The research on androgen receptor (AR) in breast cancer is advancing.Although the prognostic value of AR in triple negative breast cancer (TNBC) is controversial,a variety of studies have demonstrated that the lack of AR expression exacerbates disease progression.Moreover,the TNBC subtype of AR(-) is more aggressive than that of AR(+) due to the lack of prognostic biomarkers and therapeutic targets.With the discovery and deepening research of novel therapeutic targets such as phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin and S-phase kinase-associated protein 2 signaling pathways,as well as the emerging of immunotherapies,the treatment options for TNBC are increasing.Regarding the role of AR in TNBC,the studies about the tumor biology of AR(-)TNBC and novel biomarkers for improved management of the disease remain insufficient.In this review,we summarize the research progress of AR in TNBC,put forward avenues for future research on TNBC,and propose potential biomarkers and therapeutic strategies that warrant investigation.
Humans ; Triple Negative Breast Neoplasms/pathology* ; Receptors, Androgen/metabolism* ; Prognosis ; Biomarkers ; Signal Transduction

OBJECTIVE: To investigate the effect of inhibition of RAB27 protein family, which plays a pivotal role in exosome secretion, on biological behaviors of triple-negative breast cancer cells. METHODS: Quantitative real-time PCR and Western blotting were used to examine the expressions of RAB27 family and exosome secretion in 3 triple-negative breast cancer cell lines (MDA-MB-231, MDA-MB-468, and Hs578T) and a normal breast epithelial cell line (MCF10A). The effect of small interfering RNA (siRNA)-mediated silencing of RAB27a and RAB27b on exosome secretion in the 3 breast cancer cell lines was detected using Western blotting, and the changes in cell proliferation, invasion and adhesion were evaluated. RESULTS: Compared with normal breast epithelial cells, the 3 triple-negative breast cancer cell lines exhibited more active exosome secretion (P < 0.001) and showed significantly higher expressions of RAB27a and RAB27b at both the mRNA and protein levels (P < 0.01). Silencing of RAB27a in the breast cancer cells significantly down-regulated exosome secretion (P < 0.001), while silencing of RAB27b did not significantly affect exosome secretion. The 3 breast cancer cell lines with RAB27a silencing-induced down-regulation of exosome secretion showed obvious inhibition of proliferation, invasion and adhesion (P < 0.01) as compared with the cell lines with RAB27b silencing. CONCLUSION RAB27a plays central role in the exosome secretion in triple-negative breast cancer cells, and inhibiting RAB27a can inhibit the proliferation, invasion and adhesion of the cells.
Humans ; rab GTP-Binding Proteins/metabolism* ; Triple Negative Breast Neoplasms ; Cell Line, Tumor ; rab27 GTP-Binding Proteins/metabolism* ; RNA, Small Interfering/genetics* ; Cell Proliferation/genetics* ; Gene Expression Regulation, Neoplastic

Objective: To observe the clinical pathology features, and immune microenvironment of HER-2 intratumoral heterogeneity breast cancer. Methods: Thirty cases of HER-2 intratumoral heterogeneous breast cancer were retrospectively analyzed in Tianjin Medical University Cancer Institute and Hospital from November 2017 to June 2020. HER-2 expression was detected by immunohistochemistry and verified by dual color silver-enhanced in-situ hybridization (D-SISH). HER-2 intratumoral positive and negative regions were divided. The pathological characteristics, subtype, and the level of tumor infiltrating lymphocytes (TILs) and the expression of programmed cell death-ligand 1 (PD-L1) were evaluated respectively. Results: The proportion of HER-2 positive cells of the breast cancer ranged from 10% to 90%. The pathological type was mainly invasive non-special typecarcinoma. Six cases presented different pathological types between HER-2 positive and negative regions. The HER-2-positive areas included 2 cases of carcinoma with apocrine differentiation, and the negative areas included 2 cases of invasive micropapillary carcinoma, 1 case of invasive papillary carcinoma, and 1 case of carcinoma with apocrine differentiation. In HER-2 positive regions, 17 cases were Luminal B and 13 cases were HER-2 overexpressed types. There were 22 cases of Luminal B and 8 cases of triple negative tumors in the HER-2 negative areas. The levels of TILs in HER-2 positive and negative areas accounted for 53.3% (16/30) and 26.7% (8/30), respectively, with a statistically significant difference (P=0.035). The positive expression of PD-L1 in HER-2 positive area and HER-2 negative area were 6 cases and 9 cases, respectively. Among 8 cases with HER-2 negative regions containing triple negative components, 4 cases were positive for PD-L1 expression. Conclusions: In the case of HER-2 intratumoral heterogeneity, it is necessary to pay attention to both HER-2 positive and negative regions, and evaluate subtype separately as far as possible. For HER-2 intratumoral heterogeneous breast cancer containing triple negative components, the treatment mode can be optimized by refining the intratumoral expression of PD-L1.
Humans ; Female ; Breast Neoplasms/pathology* ; Retrospective Studies ; B7-H1 Antigen/metabolism* ; Lymphocytes, Tumor-Infiltrating/pathology* ; Carcinoma ; Tumor Microenvironment ; Triple Negative Breast Neoplasms/pathology* ; Prognosis ; Biomarkers, Tumor/metabolism*

Cluster of differentiation 36 (CD36) is a membrane glycoprotein receptor capable of binding and transporting fatty acid. Nogo-B regulates the metabolism of fatty acids in the liver and affects the development of liver cancer. To date, it remains unclear whether the interaction between CD36 and Nogo-B affects the proliferation and migration of breast cancer cells. In the current study, we aimed to determine whether the interference of CD36 and Nogo-B affects the proliferation and migration of triple-negative breast cancer (TNBC) cells. The results showed that inhibition of CD36 or Nogo-B alone can inhibit the proliferation and migration of TNBC cells, and the inhibitory effect was more pronounced when CD36 and Nogo-B were inhibited simultaneously. Meanwhile, it was found that inhibition of CD36 and Nogo-B expression can inhibit the expression of Vimentin, B-cell lympoma-2 (BCL2) and proliferating cell nuclear antigen (PCNA). In vivo, knockdown of CD36 or Nogo-B in E0771 cells reduced its tumorigenic ability, which was further enhanced by knockdown of CD36 and Nogo-B simultaneously. Mechanistically, inhibition of CD36 and Nogo-B expression can decrease fatty acid binding protein 4 (FABP4) and fatty acid transport protein 4 (FATP4) expression. Moreover, overexpression of CD36 and Nogo-B-induced cell proliferation was attenuated by FABP4 siRNA, indicating that inhibition of CD36 and Nogo-B expression could inhibit the absorption and transport of fatty acids, thereby inhibiting the proliferation and migration of TNBC. Furthermore, inhibition of CD36 and Nogo-B expression activated the P53-P21-Rb signaling pathway which contributed to the CD36 and Nogo-B-inhibited proliferation and migration of TNBC. Taken together, the results suggest that inhibition of CD36 and Nogo-B can reduce the proliferation and migration of TNBC, which provides new targets for the development of drugs against TNBC.
Humans ; Triple Negative Breast Neoplasms/metabolism* ; Cell Movement ; Cell Proliferation ; Cell Line, Tumor ; Fatty Acids

This study aims to investigate the effect and mechanism of hydnocarpin(HC) in treating triple negative breast cancer(TNBC). Cell counting kit-8(CCK-8), xCELLigence real-time cellular analysis(RTCA), and colony formation assay were employed to determine the effects of HC on the proliferation of two TNBC cell lines: MDA-MB-231 and MDA-MB-436. The effects of HC on the migration and invasion of TNBC cells were detected by high-content analysis, wound-healing assay, and Transwell assay. The changes in the epithelial-mesenchymal transition(EMT) and the expression of invasion-and migration-associated proteins [E-cadherin, vimentin, Snail, matrix metalloproteinase-2(MMP-2), and MMP-9] were detected by Western blot. Western blot and RT-qPCR were employed to determine the protein and mRNA levels of Yes-associated protein(YAP) and downstream targets(CTGF and Cyr61). TNBC cells were transfected with Flag-YAP for the overexpression of YAP, and the role of YAP as a key target for HC to inhibit TNBC malignant progression was examined by CCK-8 assay, Transwell assay, and wound-healing assay. The pathway of HC-induced YAP degradation was detected by the co-treatment of proteasome inhibitor with HC and ubiquitination assay. The binding of HC to YAP and the E3 ubiquitin ligase Ccr4-not transcription complex subunit 4(CNOT4) was detected by microscale thermophoresis(MST) assay and drug affinity responsive target stability(DARTS) assay. The results showed that HC significantly inhibited the proliferation, colony formation, invasion, and EMT of TNBC cells. HC down-regulated the protein and mRNA levels of CTGF and Cyr61. HC down-regulated the total protein level of YAP, while it had no effect on the mRNA level of YAP. The overexpression of YAP antagonized the inhibitory effects of HC on the proliferation, migration, and invasion of TNBC cells. HC promoted the degradation of YAP through the proteasome pathway and up-regulated the ubiquitination level of YAP. The results of MST and DARTS demonstrated direct binding between HC, YAP, and CNOT4. The above results indicated that HC inhibited the malignant progression of TNBC via CNOT4-mediated degradation and ubiquitination of YAP.
Humans ; Triple Negative Breast Neoplasms/metabolism* ; Matrix Metalloproteinase 2/metabolism* ; Cell Line, Tumor ; Cell Proliferation ; Cell Movement ; Ubiquitination ; RNA, Messenger/metabolism* ; Epithelial-Mesenchymal Transition ; Transcription Factors/metabolism*

Objective: PD-1/PD-L1 immune checkpoint treatment is effective for some triple-negative breast cancer populations with PD-L1 expression, but the response rate is still not satisfactory. This study aims to explore the mechanism of drug resistance to breast cancer anti-PD-1 therapies and the strategies for overcoming the resistance to PD-1therapies. Methods: By constructing a human triple-negative breast cancer drug-resistant cell line called BT-549R5 and a mouse breast cancer drug-resistant cell line called 4T1R3, and applying the whole-gene shRNA library screening, candidate drug resistance-associated molecules were obtained and verified by cytological experiments. The expression of Tyro3, Axl and MerTK of the TAM family in the 4T1R3 group was tested using the Western blot method. The down-regulation of CDK9 on the effect of T cells killing the BT-549R5 cells was observed through T cell killing tests, while the down-regulation of Tyro3 and CDK9 on the effect of anti-PD-1 therapies for transplanted breast tumors was observed in mouse tumor formation experiments. Results: The cell lines and animal models of breast cancer resistant to PD-1 treatment were successfully constructed. Tyro3, Axl and MerTK were highly expressed in 4T1R3 cells. Whole genome sequencing showed that Tyro3 and CDK9 were highly expressed in BT-549R5 cells. T cell killing experiment showed that the survival rate of BT-549R5 cells in the CDK9 down-regulated group and the control group decreased gradually with the increase of T cells, but the survival rate of BT-549R5 cells in the CDK9 down-regulated group decreased rapidly. Tumor formation experiment in mice showed that under anti-PD-1 treatment, the transplanted tumor in the 4T1R3 cell group grew rapidly compared with the 4T1 cell group (P<0.05), and the tumor volume of the 4T1R3 group was larger than that of the 4T1 group on Day 20. Nevertheless, the tumor growth rates in the CDK9-knockdown 4T1R3 cell group and the Tyro3-knockdown 4T1R3 cell group were similar to that of the 4T1 cell group, and the tumor volumes at day 20 were signiference lower than that of 4T1R3 cell group(P<0.05). Conclusions: Tyro3 and CDK9 are associated with the drug resistance to anti-PD-1 therapies for breast cancer. Inhibiting the expression of Tyro3 and CDK9 can reverse the drug resistance to breast cancer treatment.
Humans ; Animals ; Mice ; c-Mer Tyrosine Kinase/metabolism* ; Receptor Protein-Tyrosine Kinases/genetics* ; Axl Receptor Tyrosine Kinase ; Proto-Oncogene Proteins/metabolism* ; B7-H1 Antigen/genetics* ; Triple Negative Breast Neoplasms/genetics* ; Drug Resistance, Neoplasm ; Biomarkers ; Cell Line, Tumor ; Cyclin-Dependent Kinase 9

Objective: To provide survival evidence of anthracycline-free neoadjuvant chemotherapy for patients with stages Ⅱ-Ⅲ human epidermal growth factor receptor-2 (HER-2) positive and hormone receptor (HR) negative breast cancer. Methods: The prospective cohort study was conducted at the Department of Medical Oncology of Cancer Hospital, Chinese Academy of Medical Sciences. Patients with HER-2 positive and HR negative breast cancer in stages Ⅱ-Ⅲ were enrolled to receive neoadjuvant therapy (NAT) of dose-dense paclitaxel (175 mg/m(2)) plus carboplatin (AUC=4.0) biweekly for 6 cycles in combination with trastuzumab (PCbH), and matched patients who received standard adjuvant therapy of physicians' choice were recruited for survival and safety comparison. Results: From July 2013 to November 2019, 166 patients were included (neoadjuvant 51, adjuvant 115). Compared with those who received adjuvant therapy, patients receiving NAT were younger (<35 years: 19.6% vs 5.2%, P=0.014), had larger tumors (T3: 62.7% vs 7.8%, P<0.001) and more advanced diseases (stage ⅡA: 2.0% vs 41.7%, P<0.001). Patients in the neoadjuvant group all received surgery, and 96 (83.5%) in the adjuvant group received anthracycline-and-taxane-containing regimens. A total of 98 patients (49 pairs) were matched, and the covariates between the two groups were acceptably balanced. Within a median follow-up of 46.5 (range, 14-87) months, the 4-year recurrence-free survival (RFS) rate among patients who received NAT was 73.3% (95% CI: 59.0%-87.6%), versus 80.6% (95% CI: 67.9%-93.3%) among those in the adjuvant group without statistical difference (P=0.418). A similar result was observed for the 4-year overall survival (OS) [neoadjuvant versus adjuvant: 91.5% (95% CI: 81.7%-100.0%) vs 97.8% (95% CI: 93.5%-100.0%), P=0.314]. Compared with standard adjuvant therapy, PCbH was related to less neutropenia and better cardiac safety. Conclusions: These results support the consideration of anthracycline-free neoadjuvant chemotherapy combined with anti-HER-2 therapy for patients with stages Ⅱ-Ⅲ HER-2-positive and HR-negative breast cancer. Optimized regimens with both efficacy and safety are needed and to be further investigated.
Female ; Humans ; Anthracyclines/therapeutic use* ; Antibiotics, Antineoplastic/therapeutic use* ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; Carboplatin/therapeutic use* ; Chemotherapy, Adjuvant ; Hormones/therapeutic use* ; Neoadjuvant Therapy ; Paclitaxel/therapeutic use* ; Prospective Studies ; Receptor, ErbB-2/metabolism* ; Trastuzumab/therapeutic use* ; Triple Negative Breast Neoplasms/drug therapy*

Objectives: To find the prognostic factors related to early triple-negative breast cancer to optimize the therapeutic strategies, and explore the influence of programmed cell death ligand-1(PD-L1)expression in early triple-negative breast cancer on its prognosis, so as to provide support for clinical treatment decisions. Methods: Early triple-negative breast cancer patients treated at the National Cancer Center, National Clinical Research Center for Cancer, Cancer Hospital, Chinese Academy of Medical Sciences during 1st June, 2009 and 31st Oct, 2015 were enrolled in this study. All the clinicopathological data of patients were collected, and the paraffin sections of the surgical specimens were stained with estrogen receptor, progesterone receptor, human epidermal growth factor receptor-2, secreted protein acidic and rich in cysteine (SPARC), androgen receptor, PD-L1 and other antibodies by the immunohistochemical method. Kaplan-Meier survival and Cox regression curves were used for survival analysis of relevant clinical and pathological results and nomogram survival prediction models were established to explore the influence of relevant factors on the prognosis. Results: A total of 205 patients with triple-negative breast cancer were enrolled. Ninety patients (43.9%) were PD-L1 positive. The median follow-up time was 63 months. Thirty-seven patients were relapsed or recurrent and 16 patients were dead. The 5-year disease-free survival (DFS) rate and overall survival (OS) rate were 86.1% (95% CI: 81.4%-90.8%) and 93.6% (95% CI: 91.0%-97.6%), respectively, in the general population. Univariate Cox regression analysis showed that PD-L1 expression and lymph node metastasis were correlated with DFS and OS (P<0.05). In multivariate analysis, PD-L1 expression was an independent influencing factor of DFS, with PD-L1 positive patients possessing a significant survival benefit in DFS (HR=0.31, 95% CI: 0.13-0.73). Lymph node metastasis was an independent influencing factor of OS, and OS was significantly shortened in patients with positive lymph node metastasis (HR=3.24, 95% CI: 1.15-9.17). PD-L1, lymph node metastasis, menopausal status, Ki-67 index and adjuvant chemotherapy regimen were included to establish the 1- and 3-year DFS and OS nomogram prediction models, resulting in C indices of 0.698 and 0.748, respectively. Conclusions: PD-L1 expression is a predictive biomarker of good prognostic factor in triple-negative breast cancer patients. DFS is significantly prolonged in PD-L1 positive patients and OS also shows a prolongation trend. The nomogram prognosis prediction models have reference values for adjuvant chemotherapy in this patient group.
Humans ; Female ; Lymphatic Metastasis ; B7-H1 Antigen/metabolism* ; Triple Negative Breast Neoplasms/pathology* ; Breast Neoplasms ; Osteonectin/therapeutic use* ; Prognosis

Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors have led transformative breakthrough of clinical therapy for hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER-2)-negative breast cancer patients. CDK4/6 inhibitors that have been marketed in China include Ribociclib, Palbociclib, Abemaciclib and Dalpiciclib. For HR-positive HER-2-negative locally advanced and metastatic breast cancer, CDK4/6 inhibitors combined with endocrine therapy have become standard regimen, which can prolong the survival of patients. In the adjuvant treatment stage of early breast cancer, CDK4/6 inhibitors have also achieved positive results and been approved for indications. At present, CDK4/6 inhibitors have been widely used in clinical practice in China. In order to further improve the standardized application of CDK4/6 inhibitors in China, the Breast Cancer Expert Committee of the National Center for Cancer Quality Control and the Professional Committee of Clinical Research of Cancer Drugs of the Chinese Anti-Cancer Association organized the related expert to update the consensus based on the "CDK4/6 inhibitor consensus on clinical application of in the treatment of hormone receptor positive human epidermal growth factor receptor 2 negative advanced breast cancer (2021 edition)" . The updated consensus systematically introduces the pharmacological characteristics, drug monitoring and adverse event management, etc., of CDK4/6 inhibitors to promote the accuracy of clinical decision-making with the ultimate goal to prolong the overall survival of patients and improve the quality of life.
Humans ; Female ; Breast Neoplasms/pathology* ; Quality of Life ; Consensus ; Triple Negative Breast Neoplasms/drug therapy* ; Receptor, ErbB-2/metabolism* ; Protein Kinase Inhibitors ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; Cyclin-Dependent Kinase 4/metabolism*

Objective: PD-1/PD-L1 immune checkpoint treatment is effective for some triple-negative breast cancer populations with PD-L1 expression, but the response rate is still not satisfactory. This study aims to explore the mechanism of drug resistance to breast cancer anti-PD-1 therapies and the strategies for overcoming the resistance to PD-1therapies. Methods: By constructing a human triple-negative breast cancer drug-resistant cell line called BT-549R5 and a mouse breast cancer drug-resistant cell line called 4T1R3, and applying the whole-gene shRNA library screening, candidate drug resistance-associated molecules were obtained and verified by cytological experiments. The expression of Tyro3, Axl and MerTK of the TAM family in the 4T1R3 group was tested using the Western blot method. The down-regulation of CDK9 on the effect of T cells killing the BT-549R5 cells was observed through T cell killing tests, while the down-regulation of Tyro3 and CDK9 on the effect of anti-PD-1 therapies for transplanted breast tumors was observed in mouse tumor formation experiments. Results: The cell lines and animal models of breast cancer resistant to PD-1 treatment were successfully constructed. Tyro3, Axl and MerTK were highly expressed in 4T1R3 cells. Whole genome sequencing showed that Tyro3 and CDK9 were highly expressed in BT-549R5 cells. T cell killing experiment showed that the survival rate of BT-549R5 cells in the CDK9 down-regulated group and the control group decreased gradually with the increase of T cells, but the survival rate of BT-549R5 cells in the CDK9 down-regulated group decreased rapidly. Tumor formation experiment in mice showed that under anti-PD-1 treatment, the transplanted tumor in the 4T1R3 cell group grew rapidly compared with the 4T1 cell group (P<0.05), and the tumor volume of the 4T1R3 group was larger than that of the 4T1 group on Day 20. Nevertheless, the tumor growth rates in the CDK9-knockdown 4T1R3 cell group and the Tyro3-knockdown 4T1R3 cell group were similar to that of the 4T1 cell group, and the tumor volumes at day 20 were signiference lower than that of 4T1R3 cell group(P<0.05). Conclusions: Tyro3 and CDK9 are associated with the drug resistance to anti-PD-1 therapies for breast cancer. Inhibiting the expression of Tyro3 and CDK9 can reverse the drug resistance to breast cancer treatment.
Humans ; Animals ; Mice ; c-Mer Tyrosine Kinase/metabolism* ; Receptor Protein-Tyrosine Kinases/genetics* ; Axl Receptor Tyrosine Kinase ; Proto-Oncogene Proteins/metabolism* ; B7-H1 Antigen/genetics* ; Triple Negative Breast Neoplasms/genetics* ; Drug Resistance, Neoplasm ; Biomarkers ; Cell Line, Tumor ; Cyclin-Dependent Kinase 9