Purpose: The process of metastases involves the dissociation of cells from the primary tumor, penetration into the basement membrane, invasion, and exiting from the vasculature to seed and colonize distant tissues. miR-200a is involved in this multistep metastatic cascade. This study aimed to test the hypothesis that miR-200a promotes metastasis through increased anoikis resistance in breast cancer.Experimental Design: Breast cancer cells transfected with mimic or inhibitor for miR-200a were assayed for anoikis in vitro. miR-200a expression was assessed by quantitative real-time PCR (qRT-PCR). Luciferase assays, colony formation assays, and animal studies were conducted to identify the targets of miR-200a and the mechanism by which it promotes anoikis resistance.Results Conclusions: Our data suggest that miR-200a functions as anoikis suppressor and contributes to metastasis in breast cancer.

Increasing evidence has shown that chemokines and chemokine receptors are associated with tumor growth and metastasis. CCR4, an important chemokine receptor for regulating immune homeostasis, is thought to be involved in hematologic malignancies and has also recently implicated in some solid tumors, such as gastric cancer. The possible role of CCR4 in breast cancer has not been well elucidated. In this study, we show that CCR4 is differentially expressed in human breast cancer cell lines. Specifically, we find that CCR4 is overexpressed in breast cancer cell lines with high metastatic potential. More importantly, we used a combination of overexpression and RNA interference to demonstrate that CCR4 promotes breast tumor growth and lung metastasis in mice. Furthermore, we find that microvessel density is significantly increased in tumors formed by CCR4-overexpressing cells and decreased in those formed by CCR4-knockdown cells. We find that overexpression of CCR4 can enhance the chemotactic response of breast cancer cells to CCL17. However, the expression of CCR4 does not affect the proliferation of breast cancer cells in vitro. Furthermore, we show that CCR4 expression is positively correlated with HER2 expression, tumor recurrence and lymph node, lung and bone metastasis (P < 0.05). Multivariate analysis showed that CCR4 expression is a significant independent prognostic factor for overall survival (P = 0.036) but not for disease-free survival in patients with breast cancer (P = 0.071). Survival analysis indicated a strong association between CCR4 expression and lower overall survival (P = 0.0001) and disease-free survival (P = 0.016) in breast cancer.

PurposeThe purpose of this study was to determine the prognostic role of ten eleven translocation (TET) family proteins and DNA glycosylase (TDG) in patients with early breast cancer (EBC).MethodsExpression of mRNAs encoding TET1–3 and TDG in 162 breast cancer tissues was quantified using real-time polymerase chain reaction analysis. The general characteristics of patients and clinicopathologic factors were collected. Estimation of patient survival was calculated using the Kaplan–Meier method, and independent prognostic indicators were analyzed using Cox regression analysis.ResultsThe level of TET1 mRNA was significantly related to overall survival (OS) (P = 0.022). Multivariate analysis shows that the TNM stage was an independent predictor of disease-free survival (DFS) (HR = 1.761, 95% CI: 1.124–2.761, P = 0.014) and OS (HR = 2.135, 95% CI: 1.070–4.263, P = 0.032). Further, in patients with EBC who were treated with anthracyclines, Kaplan–Meier analysis indicates that the levels of TET3 and TDG mRNAs were related to DFS (P = 0.026 and 0.030, respectively), and multivariate analysis reveals that high levels of TET3 (HR = 1.944, 95% CI: 1.029–3.672, P = 0.040) and TDG (HR = 2.178, 95% CI: 1.140–4.163, P = 0.018) mRNAs were independent indicators of favorable DFS.ConclusionsOur study indicates that EBC patients with decreased expression of TET1 mRNA had worse OS and that the levels of TET3 and TDG mRNAs were independent prognostic factors for patients who received anthracycline chemotherapy.

BackgroundEmerging evidence suggests molecular and phenotypic association between treatment resistance and epithelial–mesenchymal transition (EMT) in cancer. Compared with the well-defined molecular events of miR-200a in EMT, the role of miR-200a in therapy resistance remains to be elucidated.MethodsBreast cancer cells transfected with mimic or inhibitor for miR-200a was assayed for chemoresistance in vitro. miR-200a expression was assessed by quantitative real-time PCR (qRT-PCR) in breast cancer patients treated with preoperative chemotherapy. Luciferase assays, cell proliferation assay were performed to identify the targets of miR-200a and the mechanism by which it promotes treatment resistance. Survival analysis was used to evaluate the prognosis value of miR-200a.ResultsIn this study, our results showed ectopic expression of miR-200a promotes chemoresistance in breast cancer cell lines to several chemotherapeutic agents, whereas inhibition of miR-200a enhances gemcitabine chemosensitivity in resistance cancer cells. We found overexpression of miR-200a was closely associated with poor response to preoperative chemotherapy and poor prognosis in breast cancer patients. Furthermore, knockdown of YAP1 and TP53INP1 phenocopied the effects of miR-200a overexpression, and confirmed that TP53INP1 is a novel target of miR-200a. Remarkably, TP53INP1 expression is inversely correlated with miR-200a expression in Breast cancer cell lines. Taken together, these clinical and experimental results demonstrate that miR-200a is a determinant of chemoresistance of breast cancer.ConclusionsUpregulated miR-200a enhances treatment resistance via antagonizing TP53INP1 and YAP1 in breast cancer.Electronic supplementary materialThe online version of this article (10.1186/s12885-017-3930-0) contains supplementary material, which is available to authorized users.

BackgroundInhibitors of DNA-binding (ID) proteins are known as important modulators in the regulation of cell proliferation and differentiation. This study sought to investigate the prognostic value of ID proteins in breast cancer.MethodsThe prognostic role of ID proteins in human breast cancer was investigated in 250 breast cancers, via tissue microarrays. The messenger (m)RNA and protein levels of E-cadherin were examined by quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and Western blotting, in cells overexpressing IDs. Dual-luciferase report assay was used to investigate the potential mechanism, and a migration assay was performed to investigate the influence of IDs on cell migratory activity.ResultsThe survival analysis with Kaplan–Meier and Cox regression showed that ID2 expression level, which correlated with estrogen receptor status and E-cadherin abundance, served as an independent prognostic factor for disease-free survival (DFS) (P=0.013). The prognostic value of ID2 for DFS was most significant in triple-negative breast cancer patients (P=0.009). We also found that ID2 was negatively correlated with E-cadherin expression by correlation analysis (P=0.020, Pearson’s R=−0.155). Subsequently, we explored the biological rationale and uncovered that the enforced expression of ID proteins could suppress E-cadherin expression significantly, thus increasing the migration ability of mammary epithelial cells. Then using a combination of ID2 and E-cadherin expression, the patients were classified into four subgroups with different DFS (P=0.023).ConclusionThe overexpression of ID2 can be used as a prognostic marker in breast cancer patients, especially in triple-negative breast cancer patients. ID proteins were still, unexpectedly, revealed to inhibit E-cadherin abundance.