Adjuvant tamoxifen switched to exemestane treatment in postmenopausal women with estrogen receptor-positive early breast cancer:A pragmatic,multicenter,and prospective clinical trial in China

Objective:This post-approval safety study assessed the efficacy and safety of exemestane after 2-3 years of tamoxifen treatment among postmenopausal women with estrogen receptor-positive(ER+)early breast cancer in China.Methods:Enrolled patients had received 2-3 years of tamoxifen and were then switched to exemestane for completion of 5 consecutive years of adjuvant endocrine therapy.The primary endpoint was the time from enrollment to the first occurrence of locoregional/distant recurrence of the primary breast cancer,appearance of a second primary or contralateral breast cancer,or death due to any cause.Other endpoints included the proportion of patients experiencing each event,incidence rate per annum,relationships between human epidermal growth factor receptor 2 status and time to event,and relationship between disease history variables and time to event.Results:Overall,558 patients were included in the full analysis set:397(71.1%)completed the study,20experienced an event,and 141 discontinued[47 owing to an adverse event(AE);37 no longer willing to participate].Median duration of treatment was 29.5(range,0.1-57.7)months.Median time to event was not reached.Eventfree survival probability at 36 months was 91.4%(95%CI,87.7%-95.1%).The event incidence over the total exposure time of exemestane therapy was 3.5 events/100 person-years(20/565).Multivariate analysis showed an association between tumor,lymph node,and metastasis stage at initial diagnosis and time to event[hazard ratio:1.532(95%CI,1.129-2.080);P=0.006].Most AEs were grade 1 or 2 in severity,with arthralgia(7.7%)being the most common treatment-related AE.Conclusions:This study supports the efficacy and safety of exemestane in postmenopausal Chinese women with ER+breast cancer previously treated with adjuvant tamoxifen for 2-3 years.No new safety signals were identified in the Chinese population.

ESTROGEN RECEPTOR-NEGATIVE BREAST CANCER CELLS TRANSFECTED WITH ESTROGEN RECEPTOR EXHIBIT DECREASED TUMOUR PROGRESSION AND SENSITIVITY TO GROWTH INHIBITION BY ESTROGEN

Breast cancer containing estrogen receptors (ER ) are responslve to antiestrogen treatment and have a better prognosis compared with ER-negative tumors. The loss of estrogen receptors appears to be associated with a progression to less clifferentiated cells. We transfected the human ER into the ER-negative breast cancer cell line MDA MD 231 cells. We found that expresslon of adequate ER is strong associated with the ability of human breast cancer cell growth inhibition and progression. Compared with nontransfected or mock-trans fected cells, ER-transfected cells exhibited growth slower, forming smaller colonles in soft agar and growth inhibited by estrogen and tamoxifen. Therefore reactivation or transfection of the estrogen receptor gene can be considered as therapeutic approaches to hormone-independent breast cancer.

Clinicopathological Features and Long-Term Prognostic Role of Human Epidermal Growth Factor Receptor-2 Low Expression in Chinese Patients with Early Breast Cancer:A Single-Institution Study

Objective This study aimed to comprehensively analyze and compare the clinicopathological features and prognosis of Chinese patients with human epidermal growth factor receptor 2(HER2)-low early breast cancer(BC)and HER2-IHC0 BC.Methods Patients diagnosed with HER2-negative BC(N=999)at our institution between January2011 and December 2015 formed our study population.Clinicopathological characteristics,association between estrogen receptor(ER)expression and HER2-low,and evolution of HER2 immunohistochemical(IHC)score were assessed.Kaplan-Meier method and log-rank test were used to compare the long-term survival outcomes(5-year follow-up)between the HER2-IHC0 and HER2-low groups.Results HER2-low BC group tended to demonstrate high expression of ER and more progesterone receptor(PgR)positivity than HER2-IHC0 BC group(P<0.001).The rate of HER2-low status increased with increasing ER expression levels(Mantel-Haenszelχ^(2)test,P<0.001,Pearson’s R=0.159,P<0.001).Survival analysis revealed a significantly longer overall survival(OS)in HER2-low BC group than in HER2-IHC0 group(P=0.007)in the whole cohort and the hormone receptor(HR)-negative group.There were no significant differences between the two groups in terms of disease-free survival(DFS).The discordance rate of HER2 IHC scores between primary and metastatic sites was 36.84%.Conclusion HER2-low BC may not be regarded as a unique BC group in this population-based study due to similar clinicopathological features and prognostic roles.

Spatholobus suberectus column extract inhibit estrogen receptor positive breast cancer

OBJECTIVE To investigate the inhibitory effects of Spatholobus Suberectus Column Extract(SSCE)on estrogen receptor positive(ER+)breast cancer cel MCF-7and its possible molecular mechanism.METHODS MCF-7cells were cultured without estrogen and with 17-β-estrogen(10-8mol·L-1),respectively,then treated with SSCE(0,40,80,160,320μg·m L-1).MTT assay was employed to evaluate cell viability.Flow cytometry assays were performed to underlying apoptosis and detecting cel cycle of MCF-7 cells treated with SSCE(0,80,160,320μg·mL-1).Wound healing assays was conducted to detect the migration ability.Dual luciferase reporter system was used to detect the activity of p-ERα,p-ERβpresented in intra-nuclear estrogen response element(ERE).Western blotting assay was employed to identify the expression of protein such as Bax,Bcl-2,p-ERα,p-ERβ,ERK1/2,p-ERK1/2,AKT,p-AKT,m TOR,p-m TOR,PI3K,p-PI3K.RESULTS It showed that SSCE(80,160and 320μg·mL-1)significantly decreased the viability of MCF-7.SSCE also triggered apoptosis,arrested cell cycle at G0/G1phase,inhibited migration.Dual luciferase reporter system showed that SSCE suppressed intra-nuclear p-ER activity,Western blotting analysis confirmed that SSCE did repress the expression of phosphorylated-ER alpha(p-ERα),ERK1/2,p-ERK1/2,AKT,p-AKT,pmT OR,PI3K,p-PI3K,which indicate that SSCE suppress MAPK PI3K/AKT signal pathway.CONCLUSION Our result showed that SSCE cause ER+MCF-7 cells apoptosis,G0/G1phase arresting,migration decreasing,via hypo-active of ER,suppress MAPK PI3K/AKT pathway.

Current medical treatment of estrogen receptor-positive breast cancer

Approximately 80% of breast cancers(BC) are estrogen receptor(ER)-positive and thus endocrine therapy(ET) should be considered complementary to surgery in the majority of patients. The advantages of oophorectomy, adrenalectomy and hypophysectomy in women with advanced BC have been demonstrated many years ago, and currently ET consist of(1) ovarian function suppression(OFS), usually obtained using gonadotropinreleasing hormone agonists(Gn RHa);(2) selective estrogen receptor modulators or down-regulators(SERMs or SERDs); and(3) aromatase inhibitors(AIs), or a combination of two or more drugs. For patients aged less than 50 years and ER+ BC, there is no conclusive evidence that the combination of OFS and SERMs(i.e., tamoxifen) or chemotherapy is superior to OFS alone. Tamoxifen users exhibit a reduced risk of BC, both invasive and in situ, especially during the first 5 years of therapy, and extending the treatment to 10 years further reduced the risk of recurrences. SERDs(i.e., fulvestrant) are especially useful in the neoadjuvant treatment of advanced BC, alone or in combination with either cytotoxic agents or AIs. There are two types of AIs: type Ⅰ are permanent steroidal inhibitors of aromatase, while type Ⅱ are reversible nonsteroidal inhibitors. Several studies demonstrated the superiority of the third-generation AIs(i.e., anastrozole and letrozole) compared with tamoxifen, and adjuvant therapy with AIs reduces the recurrence risk especially in patients with advanced BC. Unfortunately, some cancers are or became ET-resistant, and thus other drugs have been suggested in combination with SERMs or AIs, including cyclin-dependent kinase 4/6 inhibitors(palbociclib) and mammalian target of rapamycin(m TOR) inhibitors, such as everolimus. Further studies are required to confirm their real usefulness.

Polyubiquitination inhibition of estrogen receptor alpha and its implications in breast cancer

Estrogen receptor alpha(ERα) is detected in more than 70% of the cases of breast cancer. Nuclear activity of ERα, a transcriptional regulator, is linked to the development of mammary tumors, whereas the extranuclear activity of ERα is related to endocrine therapy resistance. ERα polyubiquitination is induced by the estradiol hormone, and also by selective estrogen receptor degraders, resulting in ERα degradation via the ubiquitin proteasome system. Moreover, polyubiquitination is related to the ERα transcription cycle, and some E3-ubiquitin ligases also function as coactivators for ERα. Several studies have demonstrated that ERα polyubiquitination is inhibited by multiple mechanisms that include posttranslational modifica-tions, intera-ctions with coregula-tors, a-nd forma-tion of specific protein complexes with ERα. These events are responsible for an increase in ERα protein levels and deregulation of its signaling in breast cancers. Thus, ERα polyubiquitination inhibition may be a key factor in the progression of breast cancer and resistance to endocrine therapy.

Estrogen receptor alpha gene amplification in breast cancer:25 years of debate

Twenty-five years ago,Nembrot and colleagues reported amplification of the estrogen receptor alpha gene(ESR1) in breast cancer,initiating a broad and still ongoing scientific debate on the prevalence and clinical significance of this genetic aberration,which affects one of the most important genes in breast cancer.Since then,a multitude of studies on this topic has been published,covering a wide range of divergent results and arguments.The reported prevalence of this alteration in breast cancer ranges from 0% to 75%,suggesting that ESR1 copy number analysis is hampered by technical and interpreter issues.To date,two major issues related to ESR1 amplification remain to be conclusively addressed:(1) The extent to which abundant amounts of messenger RNA can mimic amplification in standard fluorescence in situ hybridization assays in the analysis of strongly expressed genes like ESR1,and(2) the clinical relevance of ESR1 amplification:Such relevance is strongly disputed,with data showing predictive value for response as well as for resistance of the cancer to anti-estrogen therapies,or for subsequent development of cancers in the case of precursor lesions that display amplification of ESR1.This review provides a comprehensive summary of the various views on ESR1 amplification,and highlights explanations for the contradictions and conflicting data that could inform future ESR1 research.

Tumor biology in estrogen receptor-positive,human epidermal growth factor receptor type 2-negative breast cancer:Mind the menopausal status

Breast cancer is not one disease,but can be categorized into four major molecular subtypes according to hormone receptor [estrogen receptor(ER) and progesterone receptor(Pg R)] and human epidermal growth factor receptor type 2(HER2) expression status. Ki67 labeling index and/or multigene assays are used to classify ERpositive,HER2-negative breast cancer into luminal A and luminal B(HER2-negative) subtypes. To date,most studies analyzing predictive or prognostic factors in ER-positive breast cancer have been performed in postmenopausal women,mainly using patients and samples in adjuvant aromatase inhibitor trials. In contrast,even the clinical roles of Pg R and Ki67 have been little analyzed so far in premenopausal women. Pg R is one of the estrogen-responsive genes,and it has been reported that plasma estradiol levels are related to expression levels of estrogen-responsive genes including PGR in ER-positive breast cancer. In this article,biological differences,especially differences in expression of Pg R and Ki67 in ER-positive breast cancer between pre- and postmenopausal women are discussed. Clinical roles of Pg R and Ki67 in ER-positive breast cancer differ between pre- and postmenopausal women. We suggest that the mechanisms of development and estrogen-dependent growth of ER-positive breast cancer might differ according to menopausal status.

Intricate roles of estrogen and estrogen receptors in digestive system cancers:a systematic review

Gender disparities are evident across different types of digestive system cancers,which are typically characterized by a lower incidence and mortality rate in females compared to males.This finding suggests a potential protective role of female steroid hormones,particularly estrogen,in the development of these cancers.Estrogen is a well-known sex hormone that not only regulates the reproductive system but also exerts diverse effects on non-reproductive organs mediated through interactions with estrogen receptors(ERs),including the classic(ERαand ERβ)and non-traditional ERs[G protein-coupled estrogen receptor(GPER)].Recent advances have contributed to our comprehension of the mechanisms underlying ERs in digestive system cancers.In this comprehensive review we summarize the current understanding of the intricate roles played by estrogen and ERs in the major types of digestive system cancers,including hepatocellular,pancreatic,esophageal,gastric,and colorectal carcinoma.Furthermore,we discuss the potential molecular mechanisms underlying ERα,ERβ,and GPER effects,and propose perspectives on innovative therapies and preventive measures targeting the pathways regulated by estrogen and ERs.The roles of estrogen and ERs in digestive system cancers are complicated and depend on the cell type and tissue involved.Additionally,deciphering the intricate roles of estrogen,ERs,and the associated signaling pathways may guide the discovery of novel and tailored therapeutic and preventive strategies for digestive system cancers,eventually improving the care and clinical outcomes for the substantial number of individuals worldwide affected by these malignancies.

Increased Cellular Invasion and Proliferation via Estrogen Receptor after 17-<i>β</i>-Estradiol Treatment in Breast Cancer Cells Using Stable Isotopic Labeling with Amino Acids in Cell Culture (SILAC)

17-β-estradiol (estrogen) is a steroid hormone important to human development;however, high levels of this molecule are associated with increased risk of breast cancer primarily due to estrogen’s ability to bind and activate the estrogen receptor (ER) and initiate gene transcription. Currently, estrogen mechanisms of action are classified as genomic and non-genomic and occur in an ER-dependent and ER-independent manner. In this study, we examine estrogen signaling pathways, by measuring changes in protein expression as a function of time of exposure to estrogen in both ER-positive (MCF-7) and ER-negative (MDA-MB-231) cell lines. Using a robust experimental design utilizing isotopic labeling, two-dimensional LC-MS, and bioinformatics analysis, we report genomic and non-genomic ER regulated estrogen responsive proteins. We find a little over 200 proteins differentially expressed after estrogen treatment. Cell proliferation, transcription, actin filament capping and cell to cell signaling are significantly enriched in the MCF-7 cell line alone. Translational elongation and proteolysis are enriched in both cell lines. Subsets of the proteins presented in this study are for the first time directly associated with estrogen signaling in mammary carcinoma cells. We find that estrogen affected the expression of proteins involved in numerous processes that are related to tumorigenesis such as increased cellular division and invasion in an ER-dependent manner. Moreover, we identified negative regulation of apoptosis as a non-genomic process of estrogen. This study complements gene expression studies and highlights the need for both genomic and proteomic analyses in unraveling the complex mechanisms by which estrogen affects progression of breast cancer.

Estrogen receptor beta suppresses the androgen receptor oncogenic effects in triple-negative breast cancer

Background:Triple-negative breast cancer(TNBC)is an aggressive type of breast cancer associated with poor prognosis and limited treatment options.The androgen receptor(AR)has emerged as a potential therapeutic target for luminal androgen receptor(LAR)TNBC.However,multiple studies have claimed that anti-androgen therapy for AR-positive TNBC only has limited clinical benefits.This study aimed to investigate the role of AR in TNBC and its detailed mechanism.Methods:Immunohistochemistry and TNBC tissue sections were applied to investigate AR and nectin cell adhesion molecule 4(NECTIN4)expression in TNBC tissues.Then,in vitro and in vivo assays were used to explore the function of AR and estrogen receptor beta(ERβ)in TNBC.Chromatin immunoprecipitation sequencing(ChIP-seq),co-immunoprecipitation(co-IP),molecular docking method,and luciferase reporter assay were performed to identify key molecules that affect the function of AR.Results:Based on the TNBC tissue array analysis,we revealed that ERβand AR were positive in 21.92%(32/146)and 24.66%(36/146)of 146 TNBC samples,respectively,and about 13.70%(20/146)of TNBC patients were ERβpositive and AR positive.We further demonstrated the pro-tumoral effects of AR on TNBC cells,however,the oncogenic biology was significantly suppressed when ERβtransfection in LAR TNBC cell lines but not in AR-negative TNBC.Mechanistically,we identified that NECTIN4 promoter–42 bp to–28 bp was an AR response element,and that ERβinteracted with AR thus impeding the AR-mediated NECTIN4 transcription which promoted epithelial–mesenchymal transition in tumor progression.Conclusions:This study suggests that ERβfunctions as a suppressor mediating the effect of AR in TNBC prognosis and cell proliferation.Therefore,our current research facilitates a better understanding of the role and mechanisms of AR in TNBC carcinogenesis.

ROR2 promotes invasion and chemoresistance of triple-negative breast cancer cells by activating PI3K/AKT/mTOR signaling

Objective:This study aimed to investigate the role of receptor tyrosine kinase-like orphan receptor 2(ROR2)in triple-negative breast cancer(TNBC).Methods:ROR2 expression in primary TNBC and metastatic TNBC tissues was analyzed by immunohistochemical staining and PCR.ROR2 expression in TNBC cell lines was detected by PCR and Western blot analysis.The migration,invasion and chemosensitivity of TNBC cells with overexpression or knockdown of ROR2 were examined.Results:ROR2 expression was high in metastatic TNBC tissues.ROR2 knockdown suppressed the migration,invasion and chemoresistance of TNBC cells.ROR2 overexpression in MDA-MB-435 cells promoted the migration,invasion,and chemoresistance.Moreover,ROR2 knockdown in HC1599 and MDA-MB-435 adriamycin-resistant cells enhanced chemosensitivity to adriamycin.ROR2 could activate PI3K/AKT/mTOR signaling in TNBC cells.Conclusion:ROR2 is upregulated and promotes metastatic phenotypes of TNBC by activating PI3K/AKT/mTOR signaling.

Quercetin inhibits truncated isoform of dopamine-and cAMP-regulated phosphoprotein as adjuvant treatment for trastuzumab therapy resistance in HER2-positive breast cancer

Trastuzumab resistance is one of the causes of poor prognosis in patients with human epidermal growth factor receptor 2(HER2)-positive(HER2+)breast cancer(BC).The truncated isoform of dopamine-and cAMPregulated phosphoprotein(t-DARPP)has been reported to be involved in trastuzumab therapy resistance and promoting tumor progression.To evaluate the t-DARPP expression in BC,paired tumors and surrounding normal tissues were analyzed by real-time polymerase chain reaction and confirmed higher DARPP-32 kDa family mRNA expression in HER2+BC tumor tissues.We established 2 patient-derived xenografts(PDX)mice models to test the efficacy of trastuzumab,named model 1(non-responder)and model 2(responder).t-DARPP and p95-HER2 protein-protein interactions were detected in PDX tumor tissue from non-responders using Förster resonance energy transfer assays.Instead,there is no response from the responder.Furthermore,mechanistic studies using transwell and western blot assays demonstrated that t-DARPP could upregulate epithelial-mesenchymal transition signaling proteins,enhance p95-HER2 expression and promote cell migration.We found that quercetin effectively reduced t-DARPP expression in HER2+BC cells.In t-DARPP ShRNA-suppressed cells,quercetin synergistically enhanced trastuzumab-induced apoptotic cell death and G2/M phase arrest.In conclusion,the combination of quercetin and trastuzumab treatment by targeting t-DARPP in HER2+BC patients has the potential as a biomarker for mitigating drug resistance.

Discovery of novel covalent selective estrogen receptor degraders against endocrine-resistant breast cancer

Endocrine-resistance remains a major challenge in estrogen receptorαpositive(ERα^(+))breast cancer(BC)treatment and constitutively active somatic mutations in ERαare a common mechanism.There is an urgent need to develop novel drugs with new mode of mechanism to fight endocrineresistance.Given aberrant ERαactivity,we herein report the identification of novel covalent selective estrogen receptor degraders(cSERDs)possessing the advantages of both covalent and degradation strategies.A highly potent cSERD 29c was identified with superior anti-proliferative activity than fulvestrant against a panel of ERa+breast cancer cell lines including mutant ERα.Crystal structure of ERα-29c complex alongside intact mass spectrometry revealed that 29c disrupted ERa protein homeostasis through covalent targeting C530 and strong hydrophobic interaction collied on H11,thus enforcing a unique antagonist conformation and driving the ERαdegradation.These significant effects of the cSERD on ERαhomeostasis,unlike typical ERαdegraders that occur directly via long side chains perturbing the morphology of H12,demonstrating a distinct mechanism of action(MoA).In vivo,29c showed potent antitumor activity in MCF-7 tumor xenograft models and low toxicity.This proof-of-principle study verifies that novel cSERDs offering new opportunities for the development of innovative therapies for endocrine-resistant BC.

Expression of ΔDNMT3B Variants and Its Association with Estrogen/Progestogen Receptor Status in Breast Cancer

Objective： Our previous study has showed that △DNMT3B is the predominant form of DNMT3B in non-small cell lung cancer （NSCLC）. In this study, we aimed to explore the expression patterns of the △DNMT3B variants in breast cancer and to identify whether the pattern was similar to that in NSCLC or not and its clinical significance. Methods： Expression of seven △DNMT3B variants in 59 breast cancer and the corresponding normal tissue was measured using RT-PCR. The correlations between the expressions of △DNMT3B variants and the clinical parameters including ER/PR status, clincopathologic feature and survivals were analyzed. Results： There were significant differences in the expression ratios of △DNMT3B1-7 variants between breast cancer tissues and normal tissues （P〈0.001）. The positive ratio of △DNMT3B1-7 variants were 66%, 71%, 17%, 51%, 76.2%, 50% and 61% in tumor tissue, respectively; while 16%, 8.4%, 3.38%, 3.38%, 11.8%, 13.5% and 5.08% in the corresponding normal tissue, which was different from the pattern of △DNMT3B1-7 expression in NSCLC （62%, 76%, 2.5%, 46%, 18%, 27% and 16% in tumor tissue, respectively; while 18%, 11%, 0%, 3.3%, 0%, 0% and 0% in normal lung tissue, respectively; P〈0.0001）. Expressions of △DNMT3B2, 3B4 and 3B7 were higher in the patients with negative estrogen receptor （ER） than those with positive estrogen receptor （P=0.035, P=0.0141 and P=0.0219, respectively）. △DNMT3B7 expression was higher for the patients with negative progestogen receptor （PR） compared to those with positive progestogen receptor （P=0.0379）. Expression ratio of △DNMT3B5 in stage Ⅲ tumors is lower than that in stage Ⅰ/Ⅱ ones （P= 0.041）. But we did not find any relation between the △DNMT3B variants and the patients＇ survival. Conclusion： The pattern of △DNMT3B variants in breast cancer is different from that in NSCLC. Expressions of △DNMT3B2, 3B4 and 3B7 are associated with estrogen receptors status. While △DNMT3B7 is associated with progestogen receptor. No relation between the △DNMT3B variants and the patients＇ survival were found.

Pre-Operative MRI in HER-2 Receptor Positive and Her-2 Receptor Negative Breast Cancer: A Comparison

Objectives: MRI is the most sensitive modality for local staging of breast cancer. Herceptin receptor over-expression is seen in 15% - 30% of breast tumours, and is associated with increased aggression, poorer prognosis, higher grade at diagnosis and increased lymphatic dissemination. This study aimed at evaluating the role of MRI in Herceptin receptor positive vs negative tumours. Methods: 193 pre-operative MRIs were performed in 2021 for staging of 162 Her-2 negative and 37 Her-2 positive tumours. Recall rates and further biopsies (ipsilateral/contralateral) were assessed in both groups, and MRI largest size was compared to pathological size of invasive cancer and DCIS. Results: 36.4% of Her-2 negative tumours were recalled;further ipsilateral malignancy was identified in 13.6%. Contralateral malignancy was identified in 1.2%. 29.7% of Her-2 positive tumours were recalled;further ipsilateral malignancy was identified in 16.2%. No contralateral malignancy was seen in Her-2 positive tumours. The OR of Her-2 positive tumours having ipsilateral foci of malignancy on MRI is 0.83 (CI 0.3, 2.2). Pathological size concordance with MRI size was seen in 70.3% of Her-2 negative, and 48.6% of Her-2 positive tumours. Discordance in both groups was due to MRI size overestimation (70.8% of Her-2 negative discordance;89.4% of Her-2 positive discordance). Conclusions: Pre-operative MRI did not detect significant increased additional foci in Her-2 positive tumours. Significant concordance with pathological size was not seen in both groups;MRI overestimation was the most frequent cause for discordance in both groups. Advances in Knowledge: This study compares MRI features of Her-2 positive and Her-2 negative tumours. It demonstrates that there is no significant increased multifocality or multicentricity of Her-2 positive tumours, but MRI over-estimates size in 30% of Her-2 negative and 51% of Her-2 positive cancers.

Advances in drug resistance of triple negative breast cancer caused by pregnane X receptor

Breast cancer is the most common malignancy in women worldwide.Triplenegative breast cancer(TNBC),refers breast cancer negative for estrogen receptor,progesterone receptor and human epidermal growth factor receptor 2,characterized by high drug resistance,high metastasis and high recurrence,treatment of which is a difficult problem in the clinical treatment of breast cancer.In order to better treat TNBC clinically,it is a very urgent task to explore the mechanism of TNBC resistance in basic breast cancer research.Pregnane X receptor(PXR)is a nuclear receptor whose main biological function is to participate in the metabolism,transport and clearance of allobiological agents in PXR.PXR plays an important role in drug metabolism and clearance,and PXR is highly expressed in tumor tissues of TNBC patients,which is related to the prognosis of breast cancer patients.This reviews synthesized the important role of PXR in the process of high drug resistance to TNBC chemotherapeutic drugs and related research progress.

The Relationship of CyclinD1 and Estrogen Receptor Expression in the Process of Proliferation and Metastasis in Breast Neoplasm

The role of CyclinD1 and estrogen receptor (ER) in the process of proliferation and metastasis of breast neoplasm and their relationship were studied. The expression levels of CyclinD1 and ER in the tissue samples were detected by using flow cytometry and L SAB immunohistochemistry staining, respectively. The results showed that CyclinD1 and ER expression levels in breast cancer were significantly higher than in benign breast neoplasm (P<0.05). The CyclinD1 expression levels in stage I was much lower than in stages Ⅱ, Ⅲ, Ⅳ (P<0.05). The positive rate of ER was not related with tumor size, lymph node metastasis and TNM stage (P>0.05), but the CyclinD1 expression level in ER (+) group was significantly higher than in ER (-) group (P<0.05). It was concluded that CyclinD1 expression level might be obviously related with the proliferation and metastasis of breast neoplasm and ER.

Shugan Liangxue Decoction(舒肝凉血方)Down-Regulates Estrogen ReceptorαExpression in Breast Cancer Cells

Objective： To observe the effect of Shugan Liangxue Decoction（舒肝凉血方, SGLXD） on estrogen receptor α（ERα） in human breast cancer cells. Methods： The effect of SGLXD（0.85–5.10 mg/m L） on the proliferation of breast cancer cells were evaluated by 3-（4,5-dimethyl-2-thiazolyl）-2,5-diphenyl-2-H-tetrazolium bromide（MTT） assay. The nuclear ERα protein levels in MCF-7, T47 D and ZR-75-1 cells which treated by SGLXD for 24 h were examined by western blot and immunofluorescence assay. MCF-7 and MDA-MB-231 cells were treated by 17β-estradiol（E2） with or without SGLXD, for 24 h, and the E2 targeted genes c-myc and bcl-2 protein product was evaluated by western blot. Results： SGLXD showed dose-dependent inhibition on the proliferation of MCF-7, T47 D and ZR-75-1 cells, but did not inhibit the proliferation of MDA-MB-231 cells. Furthermore, the promotive effect on cell growth induced by E2 was also significantly inhibited by SGLXD treatment. With the treatment of 1.70, 3.40, 5.10 mg/m L SGLXD, the nuclear ERα protein level was reduced to 88.1%, 70.4% and 60.9% in MCF-7 cells, and was decreased to 43.0%, 38.4% and 5.9% in ZR-75-1 cells as compared with the control group. In T47 D cells, the nuclear ERα protein was down-regulated to 51.3% and 4.3% by 3.40 and 5.10 mg/m L SGLXD treatment. The down-regulative effect of SGLXD on nuclear ERα was confirmed by immunofluorescence assay. SGLXD decreased the protein product of c-myc and bcl-2. Conclusions： SGLXD may exhibit selective inhibition effect on the proliferation of ER positive breast cancer cells. SGLXD reduced the nuclear ERα expression and the protein product of E2 target gene c-myc and bcl-2.

A Review Study on the Effects of Estrogen Level on Vaginal Candida spp.of Women with Estrogen-Related Receptor Breast Cancer

The aim of the present study have been reported to review the estrogen level in the patients with the breast cancer and healthy individuals.Breast cancer is one of the most common diseases in women worldwide that is characterized by uncontrolled growth of malignant cells in the mammary epithelial tissue.The estrogen was found at normal level in most patients with ER-positive breast cancer and in healthy individuals,while its high level was higher among patients with ER-negative breast cancer.Many studies show evidences about the role of estrogen at a high level on the development of breast cancer.The association between the estrogen levels and the presence of Candida spp.in vagina of patients with breast cancer was reviewed.