Objectives:This study aimed to reveal the role and possible mechanism of the ubiquitin-conjugating enzyme 2T(UBE2T)in the biological activities of breast cancer stem cells(BCSCs).Methods:The specific protein and gene ...Objectives:This study aimed to reveal the role and possible mechanism of the ubiquitin-conjugating enzyme 2T(UBE2T)in the biological activities of breast cancer stem cells(BCSCs).Methods:The specific protein and gene expression were quantified by Western blotting and quantitative real-time polymerase chain reaction,the proportion of BCSCs was examined by flow cytometry,and the self-renewal and proliferation of BCSCs were verified by serial sphere formation and soft agar.Results:Increasing expression of UBE2T was drastically found in breast cancer than that in adjacent tissues.Furthermore,UBE2T overexpression significantly increased the proportion of BCSCs in breast cancer cells and promoted their self-renewal and proliferation.Silent UBE2T exhibited the opposite functions.UBE2T increased the levels of the mammalian target of rapamycin and the phosphorylated mammalian target of rapamycin.Mammalian target of rapamycin(mTOR)inhibitor rapamycin inhibited the function of UBE2T in BCSCs.Conclusion:UBE2T plays a role in BCSCs through mTOR pathway and may suggest a novel therapeutic strategy for breast cancer.展开更多
Currently, breast cancer is the most common malignant tumour in Chinese women with a high incidence rate, and recurrence and metastasis are the main reasons affecting survival. Breast Cancer Stem Cells (BCSCs) are ste...Currently, breast cancer is the most common malignant tumour in Chinese women with a high incidence rate, and recurrence and metastasis are the main reasons affecting survival. Breast Cancer Stem Cells (BCSCs) are stem cells capable of continuous regeneration in vivo with strong self-renewal ability and multidirectional differentiation potential, which are highly tumourigenic and insensitive to radiotherapy and chemotherapy, and are highly susceptible to breast cancer recurrence. Therefore, exploring the stemness of BCSCs and their mechanism associated with recurrence is important for developing new therapeutic strategies, improving therapeutic efficacy, and improving patient prognosis.展开更多
The breast cancer is the most common cause of cancer death in women. To establish an early stage in situ imaging of breast cancer cells, green quantum dots (QDs) are used as a fluorescent signal generator. The QDs b...The breast cancer is the most common cause of cancer death in women. To establish an early stage in situ imaging of breast cancer cells, green quantum dots (QDs) are used as a fluorescent signal generator. The QDs based imaging of breast cancer cells involves anti-HER2/neu antibody for labeling the over expressed HER2 on the surface of breast cancer cells. The complete assay involves breast cancer cells, biotin labeled antibody and streptavidin conjugated QDs. The breast cancer cells are grown in culture plates and exposed to the biotin labeled antibodies, and then exposed to streptavidin labeled QDs to utilize the strong and stable biotin-streptavidin interaction. Fluorescent images of the complete assay for breast cancer cells are evaluated on a microscope with a UV light source. Results show that the breast cancer cells in the complete assay are used as fluorescent cells with brighter signals compared with those labeled by the organic dye using similar parameters and the same number of cells.展开更多
Cationic polyethylenimine (PEI) with dextran fluorescein anionic (DFA) or oligodeoxynucleotide (ODN) could form polyelectrolyte complex by self-assembly as a gene delivery vector. This study was designed to inve...Cationic polyethylenimine (PEI) with dextran fluorescein anionic (DFA) or oligodeoxynucleotide (ODN) could form polyelectrolyte complex by self-assembly as a gene delivery vector. This study was designed to investigate the effects on pharmaceutical characteristics and cell uptake PEI after a long-circulation modification with poly(ethylene glycol) (PEG). DFA or ODN reacted with PEI or PEI-PEG to form polyelectrolyte complexes. Surface characters of these complexes and the retardation of ODN by PEI and PEI-PEG were evaluated. The uptake rates of DFA/PEI and DFA/PEI-PEG complexes by MCF-7 cells were evaluated by flow cytometry. Confocal laser scanning microscopy was utilized to visualize the internalization of these complexes. ODN/PEI complex showed the dependence of their size and ξ potential on the N/P ratio. ODN/PEI-PEG complex were much less affected by N/P ratio and their size was around 30 100 nm. PEI and PEI-PEG retarded ODN even at N/P ratio as low as 4, and complete retardation was found at N/P ratio of 8. The uptake rate by MCF-7 cells was direct correlated to the DFA concentration and incubation time, and the uptake rate could exceed 99% under the selected condition. The results in this study showed that PEI self-assembly polyelectrolyte complex after stealth or long circulation modification may increase the ability as a gene vector to delivery genes into cells.展开更多
Summary: The purpose of this study was to verify that a combination of mild hyperthermia and do- cetaxel chemotherapy produces synergistic antitumor effects and to explore the action mechanisms of this treatment appr...Summary: The purpose of this study was to verify that a combination of mild hyperthermia and do- cetaxel chemotherapy produces synergistic antitumor effects and to explore the action mechanisms of this treatment approach. The effects of docetaxel on the proliferation of cells from the estrogen receptor (ER)-positive human breast cancer cell line MCF-7 and the ER-negative human breast cancer cell line MDA-MB-453 were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and effective experimental concentrations of docetaxel were determined. The effects of mild hy- perthermia plus docetaxel therapy on apoptosis rate in the MCF-7 and MDA-MB-453 human breast cancer cell lines were analyzed by using flow cytometry with Annexin-V fluorescein isothiocyanate (FITC)/propidium iodide (PI) staining. The effects of these combined treatments on cell cycle progres- sion in the MCF-7 and MDA-MB-453 human breast cancer cell lines were examined by using flow cy- tometry. The effects of these combined treatments on the expression of apoptosis-related proteins and proteins in the mitogen-activated protein kinase (MAPK) pathways were analyzed by using Western blotting. The effects of these combined treatments on the expression of the heat shock protein 70 (HSP70) and the multi-drug resistance (MDR) gene product P-glycoprotein (Pgp) were examined by using Western blotting. The results showed that the half-maximal inhibitory concentration (IC50) of do- cetaxel for MCF-7 and MDA-MB-453 cells was 19.57±1.12 and 21.64±2.31 gmol/L respectively. Mild hyperthermia with docetaxel therapy could increase apoptosis rate in the MCF-7 and MDA-MB-453 cells. Apoptosis rate in MCF-7 and MDA-MB-453 cells was increased from (23.66±3.59)% and (18.51±3.17)% in docetaxel treatment group to (47.12±6.73)% and (55.16±7.42)% in mild hyperthermia plus docetaxel group, indicating that the mild hyperthermia and docetaxel therapeutic approaches exhib- ited significant synergistic antitumor effects. Treatments of mild hyperthermia plus docetaxel induced G2/M cell cycle arrest in the MCF-7 and MDA-MB-453 cells. Western blotting demonstrated that pro- teins in the MAPK pathway were expressed at higher levels in docetaxel-treated cells following mild hypothermia than those in cells treated with docetaxel alone. As compared with blank control group, cells from the mild hyperthermia plus docetaxel group exhibited significantly decreased B-cell lym- phoma 2 (Bcl-2) protein expression but slightly increased Bcl-2-associated X protein (Bax) expression. Western blotting results revealed that HSP70 and Pgp expression levels were significantly increased following mild hypothermia. It was concluded that treatments of mild hyperthermia plus docetaxel in- hibited the proliferation of human breast cancer cells, promoted apoptosis of breast cancer cells, and produced synergistic antitumor effects.展开更多
The effects of human EGFR to the malignant phenotype of human breast cancer cell line MDA-MB-231 were investigated experimentally. A retroviral vector containing a 5'1350bp fragment of the human EGFR cDNA in the a...The effects of human EGFR to the malignant phenotype of human breast cancer cell line MDA-MB-231 were investigated experimentally. A retroviral vector containing a 5'1350bp fragment of the human EGFR cDNA in the antisense orientation was transfected into targeted cells by lipofectamine. The effects on cell proliferation, cell cycle and adherent ability to extracellular matrix (ECM) components were studied after the expression of antisense transcripts to EGFR 5'1350bp fragment in target cells. In vitro studies showed that the growth ability of the transfected cells was partialy inhibited in comparison to parental cells and to cells transfected with the plasmid containing the neomycin resistance gene only. It was found that EGF (10ng/ml) had an augmenation effect on the growth of transfected MDA-AS10 cells but not MDA-MB-231 cells.Flow cytometric analysis showed that the cell cycle of the transfected cells was abnormal with a decrease of cells in G2/M and S phases and an increase of cells in G1 phase,indicating a blockage in phase G1. Immunofluorescence of EGFR expression in transfectants stained with an antiEGFR antibody was decreased and their growth in soft agarose was also severely impaired. The transfected cells showed less adherence to laminin (LN) and fibronectin (FN). In short, EGFR antisense RNA decreases the expression of EGFR on MDA-MB-231 cells and partially reverses their malignant phenotype as well.Effects of antisense EGFR on human breast cancer MDA-MB-231 cells展开更多
Recent studies have revealed that osthole,an active constituent isolated from the fruit of Cnidium monnieri(L.) Cusson,a traditional Chinese medicine,possesses anticancer activity.However,its effect on breast cancer...Recent studies have revealed that osthole,an active constituent isolated from the fruit of Cnidium monnieri(L.) Cusson,a traditional Chinese medicine,possesses anticancer activity.However,its effect on breast cancer cells so far has not been elucidated clearly.In the present study,we evaluated the effects of osthole on the proliferation,cell cycle and apoptosis of human breast cancer cells MDA-MB 435.We demonstrated that osthole is effective in inhibiting the proliferation of MDA-MB 435 cells,The mitochondrion-mediated apoptotic pathway was involved in apoptosis induced by osthole,as indicated by activation of caspase-9 and caspase-3 followed by PARP degradation.The mechanism underlying its effect on the induction of G1 phase arrest was due to the up-regulation of p53 and p21 and down-regulation of Cdk2 and cyclin D1 expression.Were observed taken together,these findings suggest that the anticancer efficacy of osthole is mediated via induction of cell cycle arrest and apoptosis in human breast cancer cells and osthole may be a potential chemotherapeutic agent against human breast cancer.展开更多
Epidermal growth factor (EGF) may increase cell motility, an event implicated in cancer cell invasion and metastasis. However, the underlying mechanisms for EGF-induced cell motility remain elusive. In this study, w...Epidermal growth factor (EGF) may increase cell motility, an event implicated in cancer cell invasion and metastasis. However, the underlying mechanisms for EGF-induced cell motility remain elusive. In this study, we found that EGF treatment could activate Ras-related C3 botulinum toxin substrate 1 (Racl), PI3K/Akt and p21- actived kinase (PAK1) along with cell migration. Ectopic expression of PAK1 K299R, a dominant negative PAK1 mutant, could largely abolish EGF-induced cell migration. Blocking PI3K/Akt signalling with LY294002 or Akt siRNA remarkably inhibited both EGF-induced PAK1 activation and cell migration. Furthermore, expression of dominant-negative Racl (T17N) could largely block EGF-induced PI3K/Akt-PAK1 activation and cell migration. Interestingly, EGF could induce a significant production of ROS, and N-acetyl-L-cysteine, a scavenger of ROS which abolished the EGF-induced ROS generation, cell migration, as well as activation of PI3K/Akt and PAK, but not Racl. Our study demonstrated that EGF-induced cell migration involves a cascade of signalling events, including activation of Racl, generation of ROS and subsequent activation of PI3K/Akt and PAK1.展开更多
Objective:To investigate the effect of piperine on human breast cancer cells.Methods:The effect of piperine on proliferation and migration of human breast cancer cells,MCF-7 and MDA-MB-231,was investigated using colon...Objective:To investigate the effect of piperine on human breast cancer cells.Methods:The effect of piperine on proliferation and migration of human breast cancer cells,MCF-7 and MDA-MB-231,was investigated using colony formation assays,wound healing assays,Matrigel migration assays,flow cytometry,RT-qPCR,and Western blotting assays.Results:Piperine inhibited the growth of MCF-7 and MDA-MB-231 cells and suppressed colony formation.Cell reduction at the G_(0)/G_(1) phase and cell arrest at the G_(2)/M phase were observed in breast cancer cells.However,the significant effect was only demonstrated in MDA-MB-231 cells.Moreover,cancer cell migration was suppressed by piperine at low concentration.RT-qPCR and Western blotting assays showed that piperine downregulated Rac1 gene and protein expression.Conclusions:Piperine could inhibit growth and migration of breast cancer cells by reducing Rac1 gene and protein expression.展开更多
The high mortality rate of breast cancer is mainly caused by the metastatic ability of cancer cells,resistance to chemotherapy and radiotherapy,and tumor regression capacity.In recent years,it has been shown that the ...The high mortality rate of breast cancer is mainly caused by the metastatic ability of cancer cells,resistance to chemotherapy and radiotherapy,and tumor regression capacity.In recent years,it has been shown that the presence of breast cancer stem cells is closely associated with the migration and metastatic ability of cancer cells,as well as with their resistance to chemotherapy and radiotherapy.The tumor microenvironment is one of the main molecular factors involved in cancer and metastatic processes development,in this sense it is interesting to study the role of platelets,one of the main communicator cells in the human body which are activated by the signals they receive from the microenvironment and can generate more than one response.Platelets can ingest and release RNA,proteins,cytokines and growth factors.After the platelets interact with the tumor microenvironment,they are called"tumor-educated platelets."Tumor-educated platelets transport material from the tumor microenvironment to sites adjacent to the tumor,thus helping to create microenvironments conducive for the development of primary and metastatic tumors.It has been observed that the clone capable of carrying out the metastatic process is a cancer cell with stem cell characteristics.Cancer stem cells go through a series of processes,including epithelial-mesenchymal transition,intravasation into blood vessels,movement through blood vessels,extravasation at the site of the establishment of a metastatic focus,and site colonization.Tumor-educated platelets support all these processes.展开更多
Epigenetic modifications have been observed as a decline in miRNA-21 expression and breast cancer stem cell(CSC)population after 3 cycles of standard chemotherapy.The epigenetic response(miRNAs expression)and CSCs are...Epigenetic modifications have been observed as a decline in miRNA-21 expression and breast cancer stem cell(CSC)population after 3 cycles of standard chemotherapy.The epigenetic response(miRNAs expression)and CSCs are also correlated in patients with Breast Cancer.In patients who tolerated chemotherapy well,miRNA-21(non-coding RNA)expression decreased significantly after three cycles of chemotherapy.The miRNA-21 expression in breast cancer tissue was quantified by quantitative PCR(real-time PCR)using the standard protocol.In addition,breast CSCs(CD44+/CD24-)were also decreased in these patients.The miRNA-21 regulates cell division,proliferation,and autophagy of cancerous cells(as it targets phosphatase and tensin homolog/AKT/transcription factor EB/programmed cell death 4/autophagy-related protein 5 and chemotherapy also produces similar effects),thereby contributing to these benefits.Therefore,when all of the targets on genes have been explored by mimic miRNA,chemotherapy combined with anti-miRNA21 therapy may prove useful in the care of cancer patients.展开更多
Breast cancer(BC) is the most common malignant neoplasm and the cause of death by cancer among women worldwide. Its development, including malignancy grade and patient prognosis, is influenced by various mutations tha...Breast cancer(BC) is the most common malignant neoplasm and the cause of death by cancer among women worldwide. Its development, including malignancy grade and patient prognosis, is influenced by various mutations that occur in the tumor cell and by the immune system's status, which has a direct influence on the tumor microenvironment and, consequently, on interactions with non-tumor cells involved in the immunological response. Among the immune response cells, dendritic cells(DCs) play a key role in the induction and maintenance of anti-tumor responses owing to their unique abilities for antigen cross-presentation and promotion of the activation of specific lymphocytes that target neoplasic cells. However, the tumor microenvironment can polarize DCs, transforming them into immunosuppressive regulatory DCs, a tolerogenicphenotype which limits the activity of effector T cells and supports tumor growth and progression. Various factors and signaling pathways have been implicated in the immunosuppressive functioning of DCs in cancer, and researchers are working on resolving processes that can circumvent tumor escape and developing viable therapeutic interventions to prevent or reverse the expression of immunosuppressive DCs in the tumor microenvironment. A better understanding of the pattern of DC response in patients with BC is fundamental to the development of specific therapeutic approaches to enable DCs to function properly. Various studies examining DCs immunotherapy have demonstrated its great potential for inducing immune responses to specific antigens and thereby reversing immunosuppression and related to clinical response in patients with BC. DCbased immunotherapy research has led to immense scientific advances, both in our understanding of the antitumor immune response and for the treatment of these patients.展开更多
Chemotherapy plays an important role in the treatment of metastatic breast cancer. It is important to monitor chemotherapeutic efficacy, to find a simple and efficient tool to guide treatment, and to predict the effic...Chemotherapy plays an important role in the treatment of metastatic breast cancer. It is important to monitor chemotherapeutic efficacy, to find a simple and efficient tool to guide treatment, and to predict the efficacy of treatment in a timely and accurate manner. This study aimed to detect mucin-1 (MUC1) - positive circulating tumor cells and MUC1 protein in the peripheral blood of patients with metastatic breast cancer and to investigate their relationship to chemotherapeutic efficacy. MUC1 mRNA was detected in the peripheral blood of 34 patients with newly diagnosed metastatic breast cancer by reverse transcription- polymerase chain reaction. The positive rates of MUC1 mRNA were 88.2% before chemotherapy and 70.6% after chemotherapy, without a significant difference (P = 0.564); MUC1 mRNA expression before chemotherapy had no correlation with treatment effectiveness (P = 0.281). The response rate of MUC1 mRNA -negative patients after first-cycle chemotherapy was significantly higher (P = 0.009) and the progression-free survival (PFS) was clearly longer than those of MUC1 mRNA-positive patients (P = 0.095). MUC1 protein in peripheral blood plasma was detected by an ELISA competitive inhibition assay. The patients with decreased MUC1 protein after chemotherapy had a significantly longer PFS than those with elevated MUC1 protein (P = 0.044). These results indicate that the outcomes of MUC1 mRNA - negative patients after chemotherapy are better than those of MUC1 mRNA-positive patients. In addition, patients with decreased expression of MUC1 protein have a better PFS.展开更多
Recently,breast cancer stem cells(BCSCs)have rapidly emerged as a novel target for the therapy of breast cancer as they play critical roles in tumor growth,maintenance,metastasis,and recurrence.Let-7 miRNA is known to...Recently,breast cancer stem cells(BCSCs)have rapidly emerged as a novel target for the therapy of breast cancer as they play critical roles in tumor growth,maintenance,metastasis,and recurrence.Let-7 miRNA is known to be downregulated in a variety of cancers,especially BCSCs,whereas CDK4 being overexpressed in human epidermal growth factor receptor 2(HER-2)overexpressing tumor cells.In this study,let-7 miRNA and CDK4-specific siRNA were chosen as therapeutic agents and co-encapsulated in Herceptinconjugated cationic liposomes for breast cancer therapy.Particle size,zeta potential,and encapsulation efficacy of mi/siRNA-loaded PEGylated liposome conjugated with Herceptin(Her-PEG-Lipo-mi/siRNA)were 176 nm,28.1 mV,and 99.7%±0.1%,respectively.Enhanced cellular uptake(86%)was observed by fluorescence microscopy when SK-BR-3 cells were treated with Her-PEG-Lipo-mi/siRNA.Also,the increased amount of let-7a mRNA and decreased amount of cellular CDK4 mRNA were observed by qRT-PCR when SK-BR-3 cells were treated with Her-PEG-Lipo-mi/siRNA,which was even more so when SK-BR-3 stem cells were used(197 vs 768 times increase for let-7a,62%vs 68%decrease for CDK4).Growth inhibition(65%)andmigration arrest(0.5%)of the cellswere achieved by the treatment of the cells with Her-PEG-Lipo-mi/siRNA,but not withmi/siRNA complex or other formulations.In conclusion,an efficient liposomal delivery system for the combination of miRNA and siRNA to target the BCSCs was developed and could be used as an efficacious therapeuticmodality for breast cancer.展开更多
Bisphenol-A(BPA) has been considered as an endocrine disrupting chemical(EDC) because it can exert estrogenic properties.For bisphenol-S(BPS) and bisphenol-F(BPF) that are BPA analogs and substitutes,their ris...Bisphenol-A(BPA) has been considered as an endocrine disrupting chemical(EDC) because it can exert estrogenic properties.For bisphenol-S(BPS) and bisphenol-F(BPF) that are BPA analogs and substitutes,their risk to estrogendependent cancer has been reported rarely compared with the numerous cases of BPA.In this study,we examined whether BPA,BPS,and BPF can lead to the proliferation,migration,and epithelial mesenchymal transition(EMT) of MCF-7 clonal variant(MCF-7 CV) breast cancer cells expressing estrogen receptors(ERs).In a cell viability assay,BPA,BPS,and BPF significantly increased proliferation of MCF-7 CV cells compared to control(DMSO) as did17β-estradiol(E2).In Western blotting assay,BPA,BPS,and BPF enhanced the protein expression of cell cycle progression genes such as cyclin D1 and E1.In addition,MCF-7 CV cells lost cell to cell contacts and acquired fibroblast-like morphology by the treatment of BPA,BPS,or BPF for 24 hours.In cell migration assay,BPA,BPS,and BPF accelerated the migration capability of MCF-7 CV cells as did E2.In relation with the EMT process,BPA,BPS,and BPF increased the protein expression of N-cadherin,while they decreased the protein expression of Ecadherin.When BPA,BPS,and BPF were co-treated with ICI 182,780,an ER antagonist,proliferation effects were reversed,the expression of cyclin D1 and cyclin E1 was downregulated,and the altered cell migration and expression of N-cadherin and E-cadherin by BPA,BPS,and BPF were restored to the control level.Thus,these results imply that BPS and BPF also have the risk of breast cancer progression as much as BPA in the induction of proliferation and migration of MCF-7 CV cells by regulating the protein expression of cell cycle-related genes and EMT markers via the ER-dependent pathway.展开更多
This study examined the effect of Notch-1 signaling on malignant behaviors of breast cancer cells by regulating breast cancer stem cells (BCSCs). BCSCs were enriched by using serum-free me- dium and knocked out of N...This study examined the effect of Notch-1 signaling on malignant behaviors of breast cancer cells by regulating breast cancer stem cells (BCSCs). BCSCs were enriched by using serum-free me- dium and knocked out of Notch-1 by using a lentiviral vector. Real-time polymerase chain reaction (RT-PCR) and Western blotting were used to detect the Notch-1 expression levels in breast cancer cell lines and BCSCs, and fl0w cytometry to detect the proportion of BCSCs in BCSC spheres. The BCSC self-renewal, migration, invasion, and tumorigenicity were examined by the tumor microsphere-forming assay and transwell assay and after xenotransplantation. The results showed that the Notch-1 silencing reduced the number of BCSC spheres, the proportion of BCSCs, and the number of cells penetrating through the transwell membrane. It also decreased the size of tumors that were implanted in the nude mice. These results suggest that Notch-1 signaling is intimately linked to the behaviors of BCSCs. Blocking Notch-1 signaling can inhibit the malignant behaviors of BCSCs, which may provide a prom- ising therapeutical approach for breast cancer.展开更多
Objective:To investigate the cytotoxic effect of ethanol extract of the stem bark of asam kandis[Garcinia cowa Roxb.(G.cowa)]on T47 D breast cancer cell line.Methods:The cytotoxicity of ethanol extract was carried out...Objective:To investigate the cytotoxic effect of ethanol extract of the stem bark of asam kandis[Garcinia cowa Roxb.(G.cowa)]on T47 D breast cancer cell line.Methods:The cytotoxicity of ethanol extract was carried out against human breast cancer cell line(T47D) by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assay.The extract was added at various concentrations(0.1.1,10 and 100 μg/mL).The level of cytotoxicity was determined by calculating the level of IC_(50),that was based on the percentage of the cell death after 24 h treatment with the extract.Cell morphological changes were observed by using inverted microscope.Results:The 3-(4.5-dimelhylthiazol-2-yl)-2.5-diphenyltelrazolium bromide assay showed that ethanol extract of G.cowa exhibited significant cytotoxic effect on T47 D with IC_(50) value of(5.10+1.68) μg/mL.Morphological alteration of the cell lines after exposure to ethanol extract of G.cowa was observed under phase contrast microscope in a dosc-dependent manner.ConclusionsThe results suggest the possible use of ethanol extract of asam kandis for preparing herbal medicine for cancer-related ailments.展开更多
We sought to determine whether STAT3 mediated tamoxifen resistance of breast cancer stem cells in vitro.The capacities for mammosphere formation and STAT3 expression of CD44+CD24-/low MCF-7 and MCF-7 were observed.Th...We sought to determine whether STAT3 mediated tamoxifen resistance of breast cancer stem cells in vitro.The capacities for mammosphere formation and STAT3 expression of CD44+CD24-/low MCF-7 and MCF-7 were observed.The CD44+CD24-/low subpopulation ratio and its sensitivity to adriamycin were analyzed in MCF-7 and TAM resistant(TAM-R) cells.Cell cycle,apoptosis,STAT3 and phospho-STAT3 changes were observed af-ter treatment with tamoxifen.Small interference RNA-mediated knockdown of STAT3 in TAM-R cells was also performed.CD44+CD24-/low MCF-7 showed higher capacities for mammosphere formation and STAT3 expression than total MCF-7.The CD44+CD24-/low subpopulation was also upregulated in TAM-R cells with less sensitivity to adriamycin than MCF-7.Cell cycle changes,anti-apoptotic effects and STAT3 changes were also found.Mean-while,the knock-down of STAT3 in TAM-R resulted in an increase in sensitivity to tamoxifen.It is concluded that STAT3 plays an essential role in breast cancer stem cells,which correlated with tamoxifen resistance.展开更多
Summary: This study aimed to evaluate the effects of Pinl inhibitor Juglone on proliferation, migration and the angiogenic ability of breast cancer cell line MCF7Adr. MCF7Adr ceils were cultured and sepa- rately trea...Summary: This study aimed to evaluate the effects of Pinl inhibitor Juglone on proliferation, migration and the angiogenic ability of breast cancer cell line MCF7Adr. MCF7Adr ceils were cultured and sepa- rately treated with Pinl inhibitor Juglone (treatment group) and DMEM without drug (control group). The cell cycle was examined by flow cytometry. Cell migration was measured by wound-healing assay. Cyclin E protein content was detected by Western blotting. The angiogenesis factor vascular endothelial growth factor (VEGF) in cell media was determined by enzyme linked immunosorbent assay. The re- suits showed that the percentage of cells in GJM phase in treatment group was significantly higher than that in control group (25.5% vs. 10.1%, P〈0.05), and that in G0/G1 phase and S stage in treatment group was significantly lower than that in control group (40.5% vs. 48.2%, and 33.7% vs. 41.7%, P〈0:05). Cyclin E protein content in treatment group was significantly lower than that in control group (39.2±7.4 vs. 100±23.1, P〈0.05). (A0-A24)/A0 value in treatment group was significantly lower than that in control group (23.9±3.8 vs. 100±14.4, P〈0.05). VEGF-A, -B, and -C contents in cell media of treatment group were significantly lower than those in control group (P〈0.05). It was suggested that Pinl inhibitor Juglone can effectively inhibit the proliferation, migration and the angiogenic ability of MCF7Adr cells, and can be used as an alternative drug therapy for breast cancer.展开更多
Breast cancer remains a leading cause of morbidity and mortality in women mainly because of the propensity of primary breast tumors to metastasize. It is composed of heterogeneous cell populations with different biolo...Breast cancer remains a leading cause of morbidity and mortality in women mainly because of the propensity of primary breast tumors to metastasize. It is composed of heterogeneous cell populations with different biological properties. Breast cancer-initiating cells have been recently identified in breast carcinoma as CD44+/CD24-/low cells, which display stem cell like properties. In the present study, we have isolated breast cancer stem cells from non-metastasis tumor tissue, which is presently at passage 18 and designated as human Breast Cancer Mesenchymal Stem Cells (hBCMSCs) line. These cells showed spindle shaped morphology and formed mammos-pheres as well as pluripotency clones indicating their stem cell nature. Molecular marker study confirmed mesenchymal nature as well as pluripotency, plasticity and oncogenicity of these cells. The hBCMSCs cell line may likely contain a heterogeneous population of malignant cells. Interestingly, we also found that these cells exhibit BRCA 2 mutation, which was found in Indian population. Overall, this study revealed that hBCMSCs cell line may represent a suitable in vitro model to study the mechanism of breast cancer which further leads to an identification of molecular targets for future breast cancer targeted therapy.展开更多
基金This research was partly supported by the Fundamental Research Funds of Shandong University(21510078614097)the Shandong Natural Science Foundation General Project(ZR2022MC093).
文摘Objectives:This study aimed to reveal the role and possible mechanism of the ubiquitin-conjugating enzyme 2T(UBE2T)in the biological activities of breast cancer stem cells(BCSCs).Methods:The specific protein and gene expression were quantified by Western blotting and quantitative real-time polymerase chain reaction,the proportion of BCSCs was examined by flow cytometry,and the self-renewal and proliferation of BCSCs were verified by serial sphere formation and soft agar.Results:Increasing expression of UBE2T was drastically found in breast cancer than that in adjacent tissues.Furthermore,UBE2T overexpression significantly increased the proportion of BCSCs in breast cancer cells and promoted their self-renewal and proliferation.Silent UBE2T exhibited the opposite functions.UBE2T increased the levels of the mammalian target of rapamycin and the phosphorylated mammalian target of rapamycin.Mammalian target of rapamycin(mTOR)inhibitor rapamycin inhibited the function of UBE2T in BCSCs.Conclusion:UBE2T plays a role in BCSCs through mTOR pathway and may suggest a novel therapeutic strategy for breast cancer.
文摘Currently, breast cancer is the most common malignant tumour in Chinese women with a high incidence rate, and recurrence and metastasis are the main reasons affecting survival. Breast Cancer Stem Cells (BCSCs) are stem cells capable of continuous regeneration in vivo with strong self-renewal ability and multidirectional differentiation potential, which are highly tumourigenic and insensitive to radiotherapy and chemotherapy, and are highly susceptible to breast cancer recurrence. Therefore, exploring the stemness of BCSCs and their mechanism associated with recurrence is important for developing new therapeutic strategies, improving therapeutic efficacy, and improving patient prognosis.
基金Supported by the Foundation for Cultivating the Excellent Doctoral Dissertation of Jiangxi Province of China (YBP08A03)~~
文摘The breast cancer is the most common cause of cancer death in women. To establish an early stage in situ imaging of breast cancer cells, green quantum dots (QDs) are used as a fluorescent signal generator. The QDs based imaging of breast cancer cells involves anti-HER2/neu antibody for labeling the over expressed HER2 on the surface of breast cancer cells. The complete assay involves breast cancer cells, biotin labeled antibody and streptavidin conjugated QDs. The breast cancer cells are grown in culture plates and exposed to the biotin labeled antibodies, and then exposed to streptavidin labeled QDs to utilize the strong and stable biotin-streptavidin interaction. Fluorescent images of the complete assay for breast cancer cells are evaluated on a microscope with a UV light source. Results show that the breast cancer cells in the complete assay are used as fluorescent cells with brighter signals compared with those labeled by the organic dye using similar parameters and the same number of cells.
基金National Nature Science Foundation of China (Grant No.30772665)Beijing Nature Science Foundation (Grant No.7083111).
文摘Cationic polyethylenimine (PEI) with dextran fluorescein anionic (DFA) or oligodeoxynucleotide (ODN) could form polyelectrolyte complex by self-assembly as a gene delivery vector. This study was designed to investigate the effects on pharmaceutical characteristics and cell uptake PEI after a long-circulation modification with poly(ethylene glycol) (PEG). DFA or ODN reacted with PEI or PEI-PEG to form polyelectrolyte complexes. Surface characters of these complexes and the retardation of ODN by PEI and PEI-PEG were evaluated. The uptake rates of DFA/PEI and DFA/PEI-PEG complexes by MCF-7 cells were evaluated by flow cytometry. Confocal laser scanning microscopy was utilized to visualize the internalization of these complexes. ODN/PEI complex showed the dependence of their size and ξ potential on the N/P ratio. ODN/PEI-PEG complex were much less affected by N/P ratio and their size was around 30 100 nm. PEI and PEI-PEG retarded ODN even at N/P ratio as low as 4, and complete retardation was found at N/P ratio of 8. The uptake rate by MCF-7 cells was direct correlated to the DFA concentration and incubation time, and the uptake rate could exceed 99% under the selected condition. The results in this study showed that PEI self-assembly polyelectrolyte complex after stealth or long circulation modification may increase the ability as a gene vector to delivery genes into cells.
文摘Summary: The purpose of this study was to verify that a combination of mild hyperthermia and do- cetaxel chemotherapy produces synergistic antitumor effects and to explore the action mechanisms of this treatment approach. The effects of docetaxel on the proliferation of cells from the estrogen receptor (ER)-positive human breast cancer cell line MCF-7 and the ER-negative human breast cancer cell line MDA-MB-453 were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and effective experimental concentrations of docetaxel were determined. The effects of mild hy- perthermia plus docetaxel therapy on apoptosis rate in the MCF-7 and MDA-MB-453 human breast cancer cell lines were analyzed by using flow cytometry with Annexin-V fluorescein isothiocyanate (FITC)/propidium iodide (PI) staining. The effects of these combined treatments on cell cycle progres- sion in the MCF-7 and MDA-MB-453 human breast cancer cell lines were examined by using flow cy- tometry. The effects of these combined treatments on the expression of apoptosis-related proteins and proteins in the mitogen-activated protein kinase (MAPK) pathways were analyzed by using Western blotting. The effects of these combined treatments on the expression of the heat shock protein 70 (HSP70) and the multi-drug resistance (MDR) gene product P-glycoprotein (Pgp) were examined by using Western blotting. The results showed that the half-maximal inhibitory concentration (IC50) of do- cetaxel for MCF-7 and MDA-MB-453 cells was 19.57±1.12 and 21.64±2.31 gmol/L respectively. Mild hyperthermia with docetaxel therapy could increase apoptosis rate in the MCF-7 and MDA-MB-453 cells. Apoptosis rate in MCF-7 and MDA-MB-453 cells was increased from (23.66±3.59)% and (18.51±3.17)% in docetaxel treatment group to (47.12±6.73)% and (55.16±7.42)% in mild hyperthermia plus docetaxel group, indicating that the mild hyperthermia and docetaxel therapeutic approaches exhib- ited significant synergistic antitumor effects. Treatments of mild hyperthermia plus docetaxel induced G2/M cell cycle arrest in the MCF-7 and MDA-MB-453 cells. Western blotting demonstrated that pro- teins in the MAPK pathway were expressed at higher levels in docetaxel-treated cells following mild hypothermia than those in cells treated with docetaxel alone. As compared with blank control group, cells from the mild hyperthermia plus docetaxel group exhibited significantly decreased B-cell lym- phoma 2 (Bcl-2) protein expression but slightly increased Bcl-2-associated X protein (Bax) expression. Western blotting results revealed that HSP70 and Pgp expression levels were significantly increased following mild hypothermia. It was concluded that treatments of mild hyperthermia plus docetaxel in- hibited the proliferation of human breast cancer cells, promoted apoptosis of breast cancer cells, and produced synergistic antitumor effects.
文摘The effects of human EGFR to the malignant phenotype of human breast cancer cell line MDA-MB-231 were investigated experimentally. A retroviral vector containing a 5'1350bp fragment of the human EGFR cDNA in the antisense orientation was transfected into targeted cells by lipofectamine. The effects on cell proliferation, cell cycle and adherent ability to extracellular matrix (ECM) components were studied after the expression of antisense transcripts to EGFR 5'1350bp fragment in target cells. In vitro studies showed that the growth ability of the transfected cells was partialy inhibited in comparison to parental cells and to cells transfected with the plasmid containing the neomycin resistance gene only. It was found that EGF (10ng/ml) had an augmenation effect on the growth of transfected MDA-AS10 cells but not MDA-MB-231 cells.Flow cytometric analysis showed that the cell cycle of the transfected cells was abnormal with a decrease of cells in G2/M and S phases and an increase of cells in G1 phase,indicating a blockage in phase G1. Immunofluorescence of EGFR expression in transfectants stained with an antiEGFR antibody was decreased and their growth in soft agarose was also severely impaired. The transfected cells showed less adherence to laminin (LN) and fibronectin (FN). In short, EGFR antisense RNA decreases the expression of EGFR on MDA-MB-231 cells and partially reverses their malignant phenotype as well.Effects of antisense EGFR on human breast cancer MDA-MB-231 cells
基金supported by grant from the Natural Science Foundation of Jiangsu Province(No.BK2011140)
文摘Recent studies have revealed that osthole,an active constituent isolated from the fruit of Cnidium monnieri(L.) Cusson,a traditional Chinese medicine,possesses anticancer activity.However,its effect on breast cancer cells so far has not been elucidated clearly.In the present study,we evaluated the effects of osthole on the proliferation,cell cycle and apoptosis of human breast cancer cells MDA-MB 435.We demonstrated that osthole is effective in inhibiting the proliferation of MDA-MB 435 cells,The mitochondrion-mediated apoptotic pathway was involved in apoptosis induced by osthole,as indicated by activation of caspase-9 and caspase-3 followed by PARP degradation.The mechanism underlying its effect on the induction of G1 phase arrest was due to the up-regulation of p53 and p21 and down-regulation of Cdk2 and cyclin D1 expression.Were observed taken together,these findings suggest that the anticancer efficacy of osthole is mediated via induction of cell cycle arrest and apoptosis in human breast cancer cells and osthole may be a potential chemotherapeutic agent against human breast cancer.
基金supported by grants from the National Natural Science Foundation of China (No. 30872926)the Program for AdvancedTalents within Six Industries of Jiangsu Province (08-D) to Dr. Luo Gu+1 种基金the Science Development Foundation of Nanjing Medical University (No. 2010NJMUZ35)the Research Program funded by Schoolof Basic Medical Science, Nanjing Medical University to Dr. Jun Du
文摘Epidermal growth factor (EGF) may increase cell motility, an event implicated in cancer cell invasion and metastasis. However, the underlying mechanisms for EGF-induced cell motility remain elusive. In this study, we found that EGF treatment could activate Ras-related C3 botulinum toxin substrate 1 (Racl), PI3K/Akt and p21- actived kinase (PAK1) along with cell migration. Ectopic expression of PAK1 K299R, a dominant negative PAK1 mutant, could largely abolish EGF-induced cell migration. Blocking PI3K/Akt signalling with LY294002 or Akt siRNA remarkably inhibited both EGF-induced PAK1 activation and cell migration. Furthermore, expression of dominant-negative Racl (T17N) could largely block EGF-induced PI3K/Akt-PAK1 activation and cell migration. Interestingly, EGF could induce a significant production of ROS, and N-acetyl-L-cysteine, a scavenger of ROS which abolished the EGF-induced ROS generation, cell migration, as well as activation of PI3K/Akt and PAK, but not Racl. Our study demonstrated that EGF-induced cell migration involves a cascade of signalling events, including activation of Racl, generation of ROS and subsequent activation of PI3K/Akt and PAK1.
基金financially supported by Mahasarakham University 2021(MSU2021).
文摘Objective:To investigate the effect of piperine on human breast cancer cells.Methods:The effect of piperine on proliferation and migration of human breast cancer cells,MCF-7 and MDA-MB-231,was investigated using colony formation assays,wound healing assays,Matrigel migration assays,flow cytometry,RT-qPCR,and Western blotting assays.Results:Piperine inhibited the growth of MCF-7 and MDA-MB-231 cells and suppressed colony formation.Cell reduction at the G_(0)/G_(1) phase and cell arrest at the G_(2)/M phase were observed in breast cancer cells.However,the significant effect was only demonstrated in MDA-MB-231 cells.Moreover,cancer cell migration was suppressed by piperine at low concentration.RT-qPCR and Western blotting assays showed that piperine downregulated Rac1 gene and protein expression.Conclusions:Piperine could inhibit growth and migration of breast cancer cells by reducing Rac1 gene and protein expression.
文摘The high mortality rate of breast cancer is mainly caused by the metastatic ability of cancer cells,resistance to chemotherapy and radiotherapy,and tumor regression capacity.In recent years,it has been shown that the presence of breast cancer stem cells is closely associated with the migration and metastatic ability of cancer cells,as well as with their resistance to chemotherapy and radiotherapy.The tumor microenvironment is one of the main molecular factors involved in cancer and metastatic processes development,in this sense it is interesting to study the role of platelets,one of the main communicator cells in the human body which are activated by the signals they receive from the microenvironment and can generate more than one response.Platelets can ingest and release RNA,proteins,cytokines and growth factors.After the platelets interact with the tumor microenvironment,they are called"tumor-educated platelets."Tumor-educated platelets transport material from the tumor microenvironment to sites adjacent to the tumor,thus helping to create microenvironments conducive for the development of primary and metastatic tumors.It has been observed that the clone capable of carrying out the metastatic process is a cancer cell with stem cell characteristics.Cancer stem cells go through a series of processes,including epithelial-mesenchymal transition,intravasation into blood vessels,movement through blood vessels,extravasation at the site of the establishment of a metastatic focus,and site colonization.Tumor-educated platelets support all these processes.
基金Supported by SERB:Department of Science and Technology,New Delhi,No. NPDF:SERB 2015/000322
文摘Epigenetic modifications have been observed as a decline in miRNA-21 expression and breast cancer stem cell(CSC)population after 3 cycles of standard chemotherapy.The epigenetic response(miRNAs expression)and CSCs are also correlated in patients with Breast Cancer.In patients who tolerated chemotherapy well,miRNA-21(non-coding RNA)expression decreased significantly after three cycles of chemotherapy.The miRNA-21 expression in breast cancer tissue was quantified by quantitative PCR(real-time PCR)using the standard protocol.In addition,breast CSCs(CD44+/CD24-)were also decreased in these patients.The miRNA-21 regulates cell division,proliferation,and autophagy of cancerous cells(as it targets phosphatase and tensin homolog/AKT/transcription factor EB/programmed cell death 4/autophagy-related protein 5 and chemotherapy also produces similar effects),thereby contributing to these benefits.Therefore,when all of the targets on genes have been explored by mimic miRNA,chemotherapy combined with anti-miRNA21 therapy may prove useful in the care of cancer patients.
文摘Breast cancer(BC) is the most common malignant neoplasm and the cause of death by cancer among women worldwide. Its development, including malignancy grade and patient prognosis, is influenced by various mutations that occur in the tumor cell and by the immune system's status, which has a direct influence on the tumor microenvironment and, consequently, on interactions with non-tumor cells involved in the immunological response. Among the immune response cells, dendritic cells(DCs) play a key role in the induction and maintenance of anti-tumor responses owing to their unique abilities for antigen cross-presentation and promotion of the activation of specific lymphocytes that target neoplasic cells. However, the tumor microenvironment can polarize DCs, transforming them into immunosuppressive regulatory DCs, a tolerogenicphenotype which limits the activity of effector T cells and supports tumor growth and progression. Various factors and signaling pathways have been implicated in the immunosuppressive functioning of DCs in cancer, and researchers are working on resolving processes that can circumvent tumor escape and developing viable therapeutic interventions to prevent or reverse the expression of immunosuppressive DCs in the tumor microenvironment. A better understanding of the pattern of DC response in patients with BC is fundamental to the development of specific therapeutic approaches to enable DCs to function properly. Various studies examining DCs immunotherapy have demonstrated its great potential for inducing immune responses to specific antigens and thereby reversing immunosuppression and related to clinical response in patients with BC. DCbased immunotherapy research has led to immense scientific advances, both in our understanding of the antitumor immune response and for the treatment of these patients.
基金supported by Beijing Capital Development Foundation for Medical Sciences(No.2007-2053)
文摘Chemotherapy plays an important role in the treatment of metastatic breast cancer. It is important to monitor chemotherapeutic efficacy, to find a simple and efficient tool to guide treatment, and to predict the efficacy of treatment in a timely and accurate manner. This study aimed to detect mucin-1 (MUC1) - positive circulating tumor cells and MUC1 protein in the peripheral blood of patients with metastatic breast cancer and to investigate their relationship to chemotherapeutic efficacy. MUC1 mRNA was detected in the peripheral blood of 34 patients with newly diagnosed metastatic breast cancer by reverse transcription- polymerase chain reaction. The positive rates of MUC1 mRNA were 88.2% before chemotherapy and 70.6% after chemotherapy, without a significant difference (P = 0.564); MUC1 mRNA expression before chemotherapy had no correlation with treatment effectiveness (P = 0.281). The response rate of MUC1 mRNA -negative patients after first-cycle chemotherapy was significantly higher (P = 0.009) and the progression-free survival (PFS) was clearly longer than those of MUC1 mRNA-positive patients (P = 0.095). MUC1 protein in peripheral blood plasma was detected by an ELISA competitive inhibition assay. The patients with decreased MUC1 protein after chemotherapy had a significantly longer PFS than those with elevated MUC1 protein (P = 0.044). These results indicate that the outcomes of MUC1 mRNA - negative patients after chemotherapy are better than those of MUC1 mRNA-positive patients. In addition, patients with decreased expression of MUC1 protein have a better PFS.
基金Supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(No.2017R1D1A1B03030849)the National Research Foundation of Korea grant funded by the Korea Government(MEST,No.2011-0030074).
文摘Recently,breast cancer stem cells(BCSCs)have rapidly emerged as a novel target for the therapy of breast cancer as they play critical roles in tumor growth,maintenance,metastasis,and recurrence.Let-7 miRNA is known to be downregulated in a variety of cancers,especially BCSCs,whereas CDK4 being overexpressed in human epidermal growth factor receptor 2(HER-2)overexpressing tumor cells.In this study,let-7 miRNA and CDK4-specific siRNA were chosen as therapeutic agents and co-encapsulated in Herceptinconjugated cationic liposomes for breast cancer therapy.Particle size,zeta potential,and encapsulation efficacy of mi/siRNA-loaded PEGylated liposome conjugated with Herceptin(Her-PEG-Lipo-mi/siRNA)were 176 nm,28.1 mV,and 99.7%±0.1%,respectively.Enhanced cellular uptake(86%)was observed by fluorescence microscopy when SK-BR-3 cells were treated with Her-PEG-Lipo-mi/siRNA.Also,the increased amount of let-7a mRNA and decreased amount of cellular CDK4 mRNA were observed by qRT-PCR when SK-BR-3 cells were treated with Her-PEG-Lipo-mi/siRNA,which was even more so when SK-BR-3 stem cells were used(197 vs 768 times increase for let-7a,62%vs 68%decrease for CDK4).Growth inhibition(65%)andmigration arrest(0.5%)of the cellswere achieved by the treatment of the cells with Her-PEG-Lipo-mi/siRNA,but not withmi/siRNA complex or other formulations.In conclusion,an efficient liposomal delivery system for the combination of miRNA and siRNA to target the BCSCs was developed and could be used as an efficacious therapeuticmodality for breast cancer.
基金supported by a grant from the NextGeneration BioGreen 21 Program(no.PJ011355-2015)supported by Priority Research Centers Program through NRF funded by the Ministry of Education,Science and Technology (2015R1A6A1A04020885)
文摘Bisphenol-A(BPA) has been considered as an endocrine disrupting chemical(EDC) because it can exert estrogenic properties.For bisphenol-S(BPS) and bisphenol-F(BPF) that are BPA analogs and substitutes,their risk to estrogendependent cancer has been reported rarely compared with the numerous cases of BPA.In this study,we examined whether BPA,BPS,and BPF can lead to the proliferation,migration,and epithelial mesenchymal transition(EMT) of MCF-7 clonal variant(MCF-7 CV) breast cancer cells expressing estrogen receptors(ERs).In a cell viability assay,BPA,BPS,and BPF significantly increased proliferation of MCF-7 CV cells compared to control(DMSO) as did17β-estradiol(E2).In Western blotting assay,BPA,BPS,and BPF enhanced the protein expression of cell cycle progression genes such as cyclin D1 and E1.In addition,MCF-7 CV cells lost cell to cell contacts and acquired fibroblast-like morphology by the treatment of BPA,BPS,or BPF for 24 hours.In cell migration assay,BPA,BPS,and BPF accelerated the migration capability of MCF-7 CV cells as did E2.In relation with the EMT process,BPA,BPS,and BPF increased the protein expression of N-cadherin,while they decreased the protein expression of Ecadherin.When BPA,BPS,and BPF were co-treated with ICI 182,780,an ER antagonist,proliferation effects were reversed,the expression of cyclin D1 and cyclin E1 was downregulated,and the altered cell migration and expression of N-cadherin and E-cadherin by BPA,BPS,and BPF were restored to the control level.Thus,these results imply that BPS and BPF also have the risk of breast cancer progression as much as BPA in the induction of proliferation and migration of MCF-7 CV cells by regulating the protein expression of cell cycle-related genes and EMT markers via the ER-dependent pathway.
基金supported by the National Nature Science Foundation of China(No.30972935)
文摘This study examined the effect of Notch-1 signaling on malignant behaviors of breast cancer cells by regulating breast cancer stem cells (BCSCs). BCSCs were enriched by using serum-free me- dium and knocked out of Notch-1 by using a lentiviral vector. Real-time polymerase chain reaction (RT-PCR) and Western blotting were used to detect the Notch-1 expression levels in breast cancer cell lines and BCSCs, and fl0w cytometry to detect the proportion of BCSCs in BCSC spheres. The BCSC self-renewal, migration, invasion, and tumorigenicity were examined by the tumor microsphere-forming assay and transwell assay and after xenotransplantation. The results showed that the Notch-1 silencing reduced the number of BCSC spheres, the proportion of BCSCs, and the number of cells penetrating through the transwell membrane. It also decreased the size of tumors that were implanted in the nude mice. These results suggest that Notch-1 signaling is intimately linked to the behaviors of BCSCs. Blocking Notch-1 signaling can inhibit the malignant behaviors of BCSCs, which may provide a prom- ising therapeutical approach for breast cancer.
基金Supported by Hibah Doktor scheme of Directorate General of Higher Education,Ministry of Education and Culture,Republic of Indonesia(Grant No.DIPA 09/UN.16/D-DD/2014)
文摘Objective:To investigate the cytotoxic effect of ethanol extract of the stem bark of asam kandis[Garcinia cowa Roxb.(G.cowa)]on T47 D breast cancer cell line.Methods:The cytotoxicity of ethanol extract was carried out against human breast cancer cell line(T47D) by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assay.The extract was added at various concentrations(0.1.1,10 and 100 μg/mL).The level of cytotoxicity was determined by calculating the level of IC_(50),that was based on the percentage of the cell death after 24 h treatment with the extract.Cell morphological changes were observed by using inverted microscope.Results:The 3-(4.5-dimelhylthiazol-2-yl)-2.5-diphenyltelrazolium bromide assay showed that ethanol extract of G.cowa exhibited significant cytotoxic effect on T47 D with IC_(50) value of(5.10+1.68) μg/mL.Morphological alteration of the cell lines after exposure to ethanol extract of G.cowa was observed under phase contrast microscope in a dosc-dependent manner.ConclusionsThe results suggest the possible use of ethanol extract of asam kandis for preparing herbal medicine for cancer-related ailments.
文摘We sought to determine whether STAT3 mediated tamoxifen resistance of breast cancer stem cells in vitro.The capacities for mammosphere formation and STAT3 expression of CD44+CD24-/low MCF-7 and MCF-7 were observed.The CD44+CD24-/low subpopulation ratio and its sensitivity to adriamycin were analyzed in MCF-7 and TAM resistant(TAM-R) cells.Cell cycle,apoptosis,STAT3 and phospho-STAT3 changes were observed af-ter treatment with tamoxifen.Small interference RNA-mediated knockdown of STAT3 in TAM-R cells was also performed.CD44+CD24-/low MCF-7 showed higher capacities for mammosphere formation and STAT3 expression than total MCF-7.The CD44+CD24-/low subpopulation was also upregulated in TAM-R cells with less sensitivity to adriamycin than MCF-7.Cell cycle changes,anti-apoptotic effects and STAT3 changes were also found.Mean-while,the knock-down of STAT3 in TAM-R resulted in an increase in sensitivity to tamoxifen.It is concluded that STAT3 plays an essential role in breast cancer stem cells,which correlated with tamoxifen resistance.
文摘Summary: This study aimed to evaluate the effects of Pinl inhibitor Juglone on proliferation, migration and the angiogenic ability of breast cancer cell line MCF7Adr. MCF7Adr ceils were cultured and sepa- rately treated with Pinl inhibitor Juglone (treatment group) and DMEM without drug (control group). The cell cycle was examined by flow cytometry. Cell migration was measured by wound-healing assay. Cyclin E protein content was detected by Western blotting. The angiogenesis factor vascular endothelial growth factor (VEGF) in cell media was determined by enzyme linked immunosorbent assay. The re- suits showed that the percentage of cells in GJM phase in treatment group was significantly higher than that in control group (25.5% vs. 10.1%, P〈0.05), and that in G0/G1 phase and S stage in treatment group was significantly lower than that in control group (40.5% vs. 48.2%, and 33.7% vs. 41.7%, P〈0:05). Cyclin E protein content in treatment group was significantly lower than that in control group (39.2±7.4 vs. 100±23.1, P〈0.05). (A0-A24)/A0 value in treatment group was significantly lower than that in control group (23.9±3.8 vs. 100±14.4, P〈0.05). VEGF-A, -B, and -C contents in cell media of treatment group were significantly lower than those in control group (P〈0.05). It was suggested that Pinl inhibitor Juglone can effectively inhibit the proliferation, migration and the angiogenic ability of MCF7Adr cells, and can be used as an alternative drug therapy for breast cancer.
文摘Breast cancer remains a leading cause of morbidity and mortality in women mainly because of the propensity of primary breast tumors to metastasize. It is composed of heterogeneous cell populations with different biological properties. Breast cancer-initiating cells have been recently identified in breast carcinoma as CD44+/CD24-/low cells, which display stem cell like properties. In the present study, we have isolated breast cancer stem cells from non-metastasis tumor tissue, which is presently at passage 18 and designated as human Breast Cancer Mesenchymal Stem Cells (hBCMSCs) line. These cells showed spindle shaped morphology and formed mammos-pheres as well as pluripotency clones indicating their stem cell nature. Molecular marker study confirmed mesenchymal nature as well as pluripotency, plasticity and oncogenicity of these cells. The hBCMSCs cell line may likely contain a heterogeneous population of malignant cells. Interestingly, we also found that these cells exhibit BRCA 2 mutation, which was found in Indian population. Overall, this study revealed that hBCMSCs cell line may represent a suitable in vitro model to study the mechanism of breast cancer which further leads to an identification of molecular targets for future breast cancer targeted therapy.