EGFR antisense RNA blocks expression of the epidermal growth factor receptor and partially reverse the malignant phenotype of human breast cancer MDA-MB-231 cells

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

Viral Etiology Relationship between Human Papillomavirus and Human Breast Cancer and Target of Gene Therapy

Objective To explore the viral etiology of human breast cancer to determine whether there are novel molecular targets for gene therapy of breast cancer and provide evidence for the research of gene therapy and vaccine development for breast cancer. Methods PCR was used to screen HPV16 and HPV18 oncogenes E6 and E7 in the SKBR3 cell line and in 76 paraffin embedded breast cancer tissue samples. RNA interference was used to knock down the expression of HPV18 E6 and E7 in SKBR3 cells, then the changes in the expression of cell-cycle related proteins, cell viability, colony formation, metastasis, and cell cycle progression were determined. Results HPV18 oncogenes E6 and E7 were amplified and sequenced from the SKBR3 cells. Of the patient samples, 6.58% and 23.68% were tested to be positive for HPV18 E6 and HPV18 E7. In the cell culture models, the knockdown of HPV18 E6 and E7 inhibited the proliferation, metastasis, and cell cycle progression of SKBR3 cell. The knockdown also clearly affected the expression levels of cell cycle related proteins. Conclusion HPV was a contributor to virus caused human breast cancer, suggesting that the oncogenes in HPV were potential targets for gene therapy of breast cancer.

Effects of Estradiol and Tamoxifen on Proliferation of Human Breast Cancer Cells and Human Endometrial Cells

The effects of estradiol and tamoxifen on the proliferation of estrogen receptor positive cells and the relationship between the tamoxifen tolerance and cell origin were investigated The tissues of human endometrium and breast cancer were randomly selected following dissection for primary cell culture After the breast cancer cells and endometrial cells were treated with 1×10 -8 mol/L estradiol and/or 1 ×10 -6 tamoxifen, 3H-labelled thymine nucleotide was used to trace the kinetics of cell proliferation There was no significant difference in the inhibition on the human endometrial cells between tamoxifen-treated group (6 3%) and control group (6 4%), but tamoxifen could significantly inhibit the proliferation of the human breast cancer cells (45 84%) as compared with control group (52 72%) Moreover, tamoxifen could significantly stimulate the proliferation of tamoxifen resistant breast cancer cells (9 64%) as compared with control group (6 32%) Estradiol could significantly stimulate the proliferation of all the three kinds of cells as compared with control group The combined use of estradiol and tamoxifen could inhibit the proliferation of the endometrial cells and breast cancer cells as compared with estradiol used alone, but on the tamoxifen resistant breast cancer cells, they could more significantly stimulate the proliferation than E2 It was concluded that E2 could stimulate the proliferation of these three kinds of cells However, the inhibitive effects of tamoxifen on the proliferation of these cells were dependent on the estradiol

Effects of bisphenol compounds on the growth and epithelial mesenchymal transition of MCF-7 CV human breast cancer cells

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.

QCM Detection of Adhesion, Spreading and Proliferation of Human Breast Cancer Cells (MCF-7) on a Gold Surface

The quartz crystal microbalance （QCM） was used to monitor the one-day incubation of human breast cancer cells （MCF-7） on the gold electrode. In combination with an optical microscope simulation experiment, the cell-population pictures at various stages, the QCM responses to the cells＇ adhesion, spreading and proliferation on the electrode surface were discussed. The △f0 and △R1 responses were found mainly from mixed effects of viscodensity and surface stress, and in proportion to the cell coverage, rather than to the number of cells at the electrode. The significant fore-and-aft changes in cyclic voltammetry and electrochemical impedance spectroscopy of the ferri-ferrocyanide redox couple also proved that the cells were adhesion to the gold surface.

A STUDY OF LECTINS IN HUMAN BREAST CANCER AND PRECANCEROUS LESIONS

This paper report the binding pattern of 12 different kinds of lectin in human breast lesions. Of the 12 kinds of lectins, WGA showed the highest binding activity to the cells of the breast tissue derived; the binding of BSL, SBA and DBA were localized to membrane or cytoplasm of cancer cells and to the lumina membrane border of the normal and benign lesions; PNA receptor is related with the differentiation of the breast; cancer; we didn't find any relationship between the lectin receptor and the tendency of metastasis of breast cancer.

Studies on mechanism of cis9,trans11-CLA and trans10,cis12-CLA inducing apoptosis of human breast cancer cell line MCF-7

Objective： The aim of the study was to explore the activities of cis9, trans11-CLA （C9, t11-CLA） and transl0, cis12-CLA （t10, c12-CLA） inhibiting tumor, and investigate their relationships with PPARy and apoptotic proteins, and mechanism of anti-cancer. Methods： The inhibitory rate, cell growth curve and apoptotic morphological observation of MCF-7 cells were obtained by MTT assay, trypan blue staining and Hoechst33342 fluorescence staining. The apoptotic rate and cell cycle were detected with flow cytometry. Transcriptional level of genes was detected with RT-PCR semi-quantitative method, and Western blot was performed to detect proteins levels. Results： The two CLA isomers could reduce cell proliferation （P 〈 0.05）, increase apoptotic rate （P 〈 0.05）, and increase obviously the transcriptional and protein levels of PPARy （P 〈 0.01）. The synchronism and correlation between the effects of CLA to PPARy and apoptotic proteins Bax, Bcl-2, Caspase 3 changes were found with the dose- and time-dependent manners. There was cooperative relation between the levels of PPARy and the rates of Bax/Bcl-2, Caspase 3 （small fragment） by experiments of PPARy inhibitor GW9662 and ligand Rosiglitazone. Conclusion： The apoptotic pathway of PPARy-Bcl-2-Caspase 3 signaling was found. The C9, t11-CLA and tl0, c12-CLA could inhibit MCF-7 cell proliferation and promote apoptosis via activating PPARy-Bcl-2-Caspase 3 pathway. CLA may be a kind of activator of PPARv.

The establishment of stable transfection of human breast cancer cell line MDA-MD-468 with exogenous PTEN gene

To investigate exogenous PTEN gene transfected human breast cancer cell line MDA-MD-468.Methods Using the lipofectamine 2000 transfection technique,wild type PTEN gene was transducted into an in vitro cultured highly metastatic breast cancer cell line MDA-MD-468.After transfection,the cells were selected by G418.The resistant clones were chosen and expanded in DMEM culture medium.RT-PCR,immunohistochemical method and western blot were used to determine the expression of target genes.Results An anti-G418 cell clone was established and expanded in culture.The transfected PTEN gene MDA-MD-468 cells showed expression of PTEN mRNA and PTEN protein.Conclusion Human breast cancer cell line MDA-MB-468 established in this study expresses consistently exogenous PTEN genes.4 refs,6 figs.

Cytotoxicity screening of Melastoma malabathricum extracts on human breast cancer cell lines in vitro

Objective:To screen the cytotoxic activity of Melasloma malabathricum(M,malubathricum)against human breast carreer cell line(MCF-7)in vitro.Methods:A three steps extraction protocol using n-hexane,chloroform and methanol as the solvents systems was carried out on leaves,stems and flowers of M.nalabathricum.Dimethyl sulfoxide was used in extracts dilution and serial dilutions were conducted to obtain five different extract concentrations(100μg/mL,50μg/mL,25μg/mL,123μg/rnL and 6.25μg/mL).The evaluation of cell growth was determined using methylene blue assay.Results:Methanol extract from the leaves showed significant anticancer activity against MCF-7cell lines with the TC_(50)value of 7.14μg/ml while methanol and chloroform extract from the flowers exhibited a moderate activity towards MCF-7 cell line,with the IC_(50)value of 33.63μg/mL and 45.76μg/mL respectively after 72 h of treatment.Conclusions:The extracts from leaves and flowers of M.nulabatkricum showed promising anticancer activity toward human breast cancer cell lines with the lowest IC_(50)at 7.14μg/mL while the extracts from stems showed less growth inhibition activity.

Studies on Focal Adhesion Kinase in Human Breast Cancer Tissue

Aim: To study Expression and Phosphorylation status of Focal Adhesion Kinase (FAK) in Human Breast Cancer tissue. To study the relation of FAK with standard clinicopathological parameters of Human Breast Cancer. Methods: Tissue collection, Protein extraction, RNA isolation, Western Blot, Immunohistochemistry, RT-PCR, ELISA, Statistical analysis. Results: All the four techniques showed upregulated expression, phosphorylation (Tyr-397) and processing of FAK in human breast cancer tissue compared to the adjacent non-tumor tissue of the same patient. Upregulation of FAK was found to be increased parallely with the advancement of cancer. Localisation of FAK was found to be membrano-cytoplasmic. FAK is upregulated both in protein and mRNA level. Expression and phosphorylation of FAK is increased specifically in the tumor regions compared to the surrounding non-tumor region. Upregulation of FAK was frequently found in ER-positive and PR-positive but Her2/neunegative breast cancer cases. Conclusion: FAK has crucial role in development and progression of human breast cancer. FAK may be considered as an indicator of human breast cancer progression. FAK processing may be considered as an indicator of invasive potential of breast cancer. FAK may be considered as a clinical indicator of human breast cancer development and progression.

Sensitivity Evaluation of Two Human Breast Cancer Cell Lines to Tamoxifen through Apoptosis Induction

Tamoxifen citrate (TAM) has been used to treat breast cancer in women for many years. The com-parative effects of TAM in inducing apoptosis were evaluated in estrogen receptor-positive (ER- positive MCF-7) and estrogen receptor-negative (ER-negative MDA-MB-231) human breast cancer cell lines in vitro in order to determine if these two cell lines differ in their sensitivity to TAM. Mi-tochondrial membrane permeability potential disruption was assessed in both cell lines by a lip-ophilic cationic dye (DePsipher assay, Trevigen, Inc.) utilizing fluorescence microscopy. Using this specific fluorochrome, we were able to associate mitochondrial membrane disruption to early, mid-, and late apoptotic cells. TAM induced cell death via apoptosis in both ER-positive and ER- negative cells, however, apoptosis induction was more pronounced in ER-positive MCF-7 compared to ER-negative MDA-MB-231 breast cancer cells. These findings may have some therapeutic use in the treatment of estrogen dependent and estrogen independent breast cancer.

Effects of Volatile Oils of Sichuan Citrisarcodactylis fructus on Proliferation and Apoptosis of MCF-7 Human Breast Cancer Cells

[Objectives] To study the effects of volatile oils of Sichuan Citrisarcodactylis fructus on proliferation and apoptosis of MCF-7human breast cancer cells.[Methods]CCK-8 method was used to measure the cell proliferation,the flow cytometry was used to measure changes in cell cycle,Western blot was used to detect p53 and cyclin D1 activity changes,TUNEL method was used to measure percentage of apoptotic cells,inverted phase contrast microscope and transmission electron microscope were used to observe morphology of MCF-7 cells treated with different concentrations.[Results]When the concentration was 5-50 μmol/L,the cell proliferation inhibition rate increased significantly(P <0. 05),G2/M phase decreased significantly( P < 0. 05),eventually disappeared completely,G1 phase significantly increased with time and concentration( P < 0. 05),finally reached 90. 0%; the activity of cyclin D1 significantly declined( P < 0. 05),while the activity of p53 had no significant change( P > 0. 05). The apoptotic rate of MCF-7 cells significantly increased with the extension of time( P < 0. 05). At6 h,12 h and 24 h of action time,the apoptotic rate of MCF-7 cells significantly increased with the increase in volatile oil concentration(P <0. 05). Morphological observation showed that the apoptosis of MCF-7 cells was obvious.[Conclusions]The volatile oils of Citrisarcodactylis fructus have obvious inhibition of proliferation of MCF-7 cells and function of inducing apoptosis,and the effects took on the dose and time dependent. 5-50 μmol/L volatile oil of Sichuan Citrisarcodactylis fructus can inhibit the proliferation of MCF-7 cells and induce the apoptosis of MCF-7 cells through inhibiting the cyclin D1.

RADIOIMMUNOIMAGING OF HUMAN BREAST CANCER XENOGRAFTS IN NUDE MICE BY USING HUMAN ANTI-HUMAN BREAST CANCER MONOCLONAL ANTIBODIES

In this study, the human breast cancer-bearing nude mice model has been established and the radioim-munoimaging was carried out by using human anti-human monoclonal antibodies. The results showed that the breast tumor-bearing nude mice received 131I-McAb-CM-l had a clear image of the xenograft during 4 to 6 days after injection and at the same time T/NT all over 1. 0. The highest T/NT reached 7.1. It demonstrates that McAb-CM-1 can specially combine with breast cancer tissues and hopefully it could be used clinically to improve accurate rate of the early breast cancer diagnosis.

Tyrosine kinase inhibitors and human epidermal growth factor receptor-2 positive breast cancer

The body of evidence investigating human epidermal growth factor receptor-2(HER2)directed therapy in patients with breast cancer(BC)has been growing within the last decade.Recently,the use of tyrosine kinase inhibitors(TKIs)has been of particular interest in the treatment of human malignancies.This literature commentary is intended to highlight the most recent findings associated with the widely-studied TKI agents and their clinical significance in improving the outcomes of HER2 positive BC.

A comparison study of the cytotoxicity of salinomycin and salinomycin sodium toward human breast cancer stem cells as well as breast cancer cells

Salinomycin（SAL）,a polyether antibiotic isolated from Streptomyces albus,is widely used as an anticoccidial drug in poultry and other livestock and is furthermore fed to ruminescent animals to improve nutrient absorption and feed efficiency.It has recently been shown to act as a specific inhibitor of cancer stem cells.At present,the price of salinomycin sodium（SAL-Na） is 10 fold lower than that of salinomycin,however,there is no report about the comparison of the inhibitory effects of SAL and SAL-Na on cancer stem cells as well as cancer cells.In the present study,side population cells（SP cells）and non-SP cells （NSP cells）sorted from human breast cancer cell line MCF-7 were chosen as the models of cancer stem cells and cancer cells, respectively.SRB assay was performed to compare the cytotoxicity of SAL and SAL-Na.First of all,SP cells were sorted from MCF-7 cells via FACSDiva flow cytometry.Secondly,the sorted SP cells were identified with the surface makers（CD44~＋/CD24^-） of breast cancer stem cells.Finally,the inhibitory effects of SAL and SAL-Na were evaluated on the sorted SP cells and NSP cells.Results showed that,as compared to breast cancer cells,the inhibitory effect of free SAL or free SAL-Na was more potent in breast cancer stem cells.Furthermore,the inhibitory effects of free SAL and free SAL-Na had no significant difference for the SP cells as well as the NSP cells when they were in the same concentration.Thus,it suggested that salinomycin sodium should be considered as a potential candidate to take the place of salinomycin in cancer stem cells research,due to their similar inhibitory effects on cancer stem cells.

Loss of the vitamin D receptor in human breast and prostate cancers strongly induces cell apoptosis through downregulation of Wnt/β-catenin signaling

Vitamin D co-regulates cell proliferation, differentiation and apoptosis in numerous tissues, including cancers. The known anti-proliferative and pro-apoptotic actions of the active metabolite of vitamin D, 1,25-dihydroxy-vitamin D [1,25（OH）2D] are mediated through binding to the vitamin D receptor （VDR）. Here, we report on the unexpected finding that stable knockdown of VDR expression in the human breast and prostate cancer cell lines, MDA-MB-231 and PC3, strongly induces cell apoptosis and inhibits cell proliferation in vitro. Implantation of these VDR knockdown cells into the mammary fat pad （MDA-MB-231）, subcutaneously （PC3） or intra-tibially （both cell lines） in immune-incompetent nude mice resulted in reduced tumor growth associated with increased apoptosis and reduced cell proliferation compared with controls. These growth-retarding effects of VDR knockdown occur in the presence and absence of vitamin D and are independent of whether cells were grown in bone or soft tissues. Transcriptome analysis of VDR knockdown and non-target control cell lines demonstrated that loss of the VDR was associated with significant attenuation in the Wnt/0-catenin signaling pathway. In particular, cytoplasmic and nuclear β-catenin protein levels were reduced with a corresponding downregulation of downstream genes such as Axin2, Cyclin D1, interleukin-6 （IL-6）, and IL-8. Stabilization of 0-catenin using the GSK-3β inhibitor BIO partly reversed the growth-retarding effects of VDR knockdown. Our results indicate that the unliganded VDR possesses hitherto unknown functions to promote breast and prostate cancer growth, which appear to be operational not only within but also outside the bone environment. These novel functions contrast with the known anti-proliferative nuclear actions of the liganded VDR and may represent targets for new diagnostic and therapeutic approaches in breast and prostate cancer.

Lymphocyte subsets predictive value and possible involvement of human papilloma virus infection on breast cancer molecular subtypes

AIM To detect human papilloma virus(HPV) presence and to characterize cellular immune response in breast cancer patients. METHODS A total of 74 women were included, of which 48 samples were from patients diagnosed with breast cancer and 26 patients with benign pathology of the breast. Molecular subtype classification was performed based on the immunohistochemical reports of the tumor piece. HPV genome detection and genotyping from fresh breast biopsies was performed using the INNO-LIPA HPV Genotyping Extra test(Innogenetics, Ghent, Belgium). CD3+, CD4+, CD8+ and natural killer(NK)+ cells levels from peripheral blood samples from patients with breast cancer and benign pathology were measured by flow cytometry. RESULTS Luminal A was the most frequent breast cancer molecular subtype(33.33%). HPV was detected in 25% of the breast cancer patients, and genotype 18 was the most frequent in the studied population. The mean of CD3+, CD4+ and CD8+ subpopulations were decreased in patients with breast cancer, in relation to those with benign pathology, with a statistically significant difference in CD8+ values(P = 0.048). The mean of NK+ cells was increased in the benign pathology group. The average level of CD3+, CD4+, CD8+ and NK+ cells decreased as the disease progressed. HER2+ and Luminal B HER2+ tumors had the lowest counts of cell subsets. HPV breast cancer patients had elevated counts of cellular subsets. CONCLUSION Determining level changes in cellular subsets in breast cancer patients is a useful tool to evaluate treatment response.

A novel mouse model of human breast cancer stem-like cells with high CD44^＋CD24^–/lower phenotype metastasis to human bone

Background A satisfactory animal model of breast cancer metastasizing to bone is unavailable. In this study, we used human breast cancer stem-like cells and human bone to build a novel “human-source” model of human breast cancer skeletal metastasis. Methods Human breast cancer stem-like cells, the CD44^＋/CD24^-/lower subpopulation, was separated and cultured. Before injection with the stem-like cells, mice were implanted with human bone in the right or left dorsal flanks. Animals in Groups A, B, and C were injected with 1×10^5, 1×10^6 human breast cancer stem-like cells, and 1×10^6 parental MDA-MB-231 cells, respectively. A positive control group （D） without implantation of human bone was also injected with 1×10^6 MDA-MB-231 cells. Immunohistochemistry was performed for determination of CD34, CD105, smooth muscle antibody, CD44, CD24, cytokine, CXC chemokine receptor-4 （CXCR4）, and osteopontin （OPN）. mRNA levels of CD44, CD24, CXCR4, and OPN in bone metastasis tissues were analyzed by real-time quantitative polymerase chain reaction （PCR）.Results Our results demonstrated that cells in implanted human bones of group B, which received 1×10^6 cancer stem-like cells, stained strongly positive for CD44, CXCR4, and OPN, whereas those of other groups showed no or minimum staining. Moreover, group B had the highest incidence of human bone metastasis （77.8%, P=0.0230） and no accompaniment of other tissue metastasis. The real-time PCR showed an increase of CD44, CXCR4, and OPN mRNA in metastatic bone tissues in group B compared with those of groups C and D, however the expression of CD24 mRNA in group B were the lowest. Conclusions In the novel “human source” model of breast cancer, breast cancer stem-like cells demonstrated a higher human bone-seeking ability. Its mechanism might be related to the higher expressions of CD44, CXCR4, and OPN, and the lower expression of CD24 in breast cancer stem-like cells.

Application of pegylated recombinant human granulocyte colony-stimulating factor(PEG-rhG-CSF) for the prevention of neutropenia in triple negative breast cancer patients older than 65 years during adjuvant chemotherapy

Objective The aim of this study was to compare the efficacy and safety of pegylated recombinant human granulocyte colony-stimulating factor(PEG-rhG-CSF)and recombinant human granulocyte colonystimulating factor(rhG-CSF)for the prevention of neutropenia in elderly breast cancer patients during adjuvant chemotherapy.Methods A total of 45 oncology inpatients with breast cancer,who received adjuvant chemotherapy and were older than 65 years from May 2017 to October 2018 in the General Hospital of the Northern Theater of the Chinese people’s Liberation Army,were included.Epirubivin Cyclophoshamide-Docetaxel(EC-T)sequential adjuvant chemotherapy was chosen.Forty-five patients were randomly divided into two groups;25 patients in the treatment group were treated with PEG-rhG-CSF and 20 patients in the control group were not treated with PEG-rhG-CSF,but only rhG-CSF.The experimental group was treated with the PEG-rhG-CSF at the end of chemotherapy for 24–48 h,with a 6 mg subcutaneous injection once per chemotherapy cycle.In the control group,rhG-CSF was administered after 48 h of chemotherapy,with a 100μg subcutaneous injection,1/d,d 1–7.The dosage could be increased step by step with the exacerbation of neutropenia.The primary aims of this study was to discover the incidence of leukopenia,neutropenia,neutrophilic fever,and adverse reactions in the two groups.Results The incidence of neutropenia,neutrophilic fever and adverse reactions decreased in the treatment group compared to the control group,but no significant difference existed between two groups(P>0.05).Patients in treatment group had a lower,but not statistically significant,incidence of adverse reactions(P>0.05).Conclusion Applying PEG-rhG-CSF could be effective in preventing neutropenia in elderly patients with postoperative adjuvant chemotherapy to treat breast cancer.It may effectively control the occurrence of neutropenia after chemotherapy and reduce the chance of infection.The incidence of side effects,such as fever and bone pain,was low.The adverse drug reactions were well tolerated by patients,which could ensure the smooth progress of chemotherapy.

Loss of human epidermal receptor-2 in human epidermal receptor-2+breast cancer after neoadjuvant treatment:A case report

BACKGROUND Human epidermal receptor-2(HER-2)expression has been reported to be discordant between primary tumor and metastatic tissue.CASE SUMMARY We presented a case diagnosed with the HER-2+breast cancer patient who exhibited changes in the expression of HER-2 receptors on tumour samples from surgical specimens obtained after neoadjuvant treatment(NAT)compared with initial biopsy.The patient underwent a HER-2-targeted therapy consequently,in spite of HER+gene loss.After the surgery,the patient subsequently underwent endocrine therapy and radiotherapy.CONCLUSION Changes in HER-2 expression after NAT should be retested by physicians and pathologists before systemic treatment instead of avoiding further HER-2-targeted therapy,and we will perform immunohistochemical multiple-spot biopsy analyses of other important clinical issues to better define prognosis and tailor subsequent adjuvant therapy.