Early versus late distant metastasis and adjuvant chemotherapy alone versus both radiotherapy and chemotherapy in molecular apocrine breast cancer

Clinical significance of PDEF factor expression and its relation to androgen receptor in ER- breast cancer

AIMS

The mechanism of androgen receptor (AR) promoting tumour growth in oestrogen receptor-negative (ER^- ) breast cancer (BC) is undetermined. Prostate-derived ETS factor (PDEF) is highly restricted to the hormone-regulated tissues of epithelial cells, such as those in the prostate, breast and other tissues. It has been demonstrated that PDEF expression is associated with AR in prostate cancer. In this research, we aimed to investigate the relationship between PDEF and AR in ER^- BC.

METHODS AND RESULTS

We immunohistochemically evaluated the correlation between PDEF and AR expression in 246 cases of ER^- invasive BC, and investigated their relationship in ER^- BC cell lines. The expression of PDEF was associated with the positive expression of AR (P < 0.001) and a worse survival rate (P = 0.006). PDEF⁺ tumours were significantly more often AR⁺ (P < 0.001). AR and PDEF were more often co-expressed and the series of AR⁺ PDEF⁺ (126 of 246, 51.2%) had a poor survival rate (P = 0.046). In Cox models, PDEF expression (P = 0.028) was an independent predictor for overall survival (OS). At the cellular protein and mRNA levels, our experiments also showed a statistically significant positive correlation between PDEF and AR, and that PDEF may be regulated by AR.

CONCLUSIONS

PDEF is associated with markers of bad prognosis, supporting its role as a growth promoter in ER^- BC. Our findings also provide evidence that PDEF is strongly correlated with AR expression in ER^- breast cancer; it may be a downstream target gene of AR and a potential prognostic factor in ER^- BC.

Late Endobronchial Pulmonary Metastasis in a Patient with Breast Cancer

The lung is a common location for malignant metastases. However, endobronchial metastases from nonpulmonary neoplasms are rare. Metastatic breast cancer usually occurs in 2-3 years of the disease course. A 65-year-old woman visited our hospital for the evaluation of dry cough. The patient had a history of breast cancer, which was treated with modified radical mastectomy and axillary dissection 10 years ago; she was then treated with aromatase inhibitor for 5 years. Chest X-ray revealed right hilum enlargement. Thorax computed tomography revealed a 35-mm diameter mass that was localized in the right hilum. Fiberoptic bronchoscopy was performed, and an endobronchial lesion was observed in the right main lobe carina. Pathological evaluation revealed that the mass was a metastasis of the invasive ductal carcinoma of the breast. Weekly paklitaxel chemotherapy was initiated because of the symptomatic disease. We reported the case of a patient with breast cancer who had an endobronchial metastasis. Her disease-free interval was 10 years. This case indicates that a long-term follow-up of breast cancer is necessary, and biopsies must be performed to make a final diagnosis when any suspicious hilum enlargement is observed.

Androgen receptor and heat shock protein 27 co-regulate the malignant potential of molecular apocrine breast cancer

Background

The most striking feature of molecular apocrine breast cancer (MABC) is the expression of androgen receptor (AR). We report here the mechanism of the AR in regulating the behavior of MABC.

Methods

The MABC cell line, MDA-MB-453, and the nonMABC cell line, MCF7, were used in this study. The effect of dihydrotestosterone (DHT) and heat shock protein 27 (HSP27) on cell proliferation was quantified using the cell counter kit-8 (CCK8) and clonogenic assays in vitro and by a xenograft tumor model in vivo. The expression of the AR and HSP27 was analyzed using western blot, qPCR, and immunofluorescence assays. Complexes of the AR and HSP27 were detected by co-immunoprecipitation (Co-IP).

Results

In MDA-MB-453 cells, DHT promoted cell proliferation and stimulated AR and HSP27 translocation from the cytoplasm to the nucleus, whereas, it inhibited MCF7 cell growth, and only the AR translocated into the nucleus. HSP27 knock-down decreased the proliferative ability of MDA-MB-453 cells, which could be rescued by DHT, while HSP27 and DHT had synergistic effects on MCF7 cells. HSP27 phosphorylation was a prerequisite for AR translocation into the nucleus, especially phosphorylation on serine 82. In addition, DHT stimulated the tumorigenic and metastatic capacities of MDA-MB-453 cells, while HSP27 knock-down decreased the rate of tumor formation and induced apoptosis in cells.

Conclusions

The results suggest that HSP27 assists the AR in regulating the malignant behavior of MABC, and these findings might be helpful in the treatment of MABC.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0762-y) contains supplementary material, which is available to authorized users.

The importance of EGFR as a biomarker in molecular apocrine breast cancer

Molecular apocrine breast cancer (MABC) is a molecular subtype with a poor prognosis, and there is urgent need to find new therapeutic targets. Epidermal growth factor receptor (EGFR) plays an important part in regulating the biological behavior of tumor cells, and EGFR-targeted drugs have already been used in therapy for lung and colorectal cancers. The purpose of this study was to analyze the significance of EGFR expression in MABC. A total of 400 patients with invasive breast cancer were analyzed, including 200 MABC and 200 non-MABC cases. Immunohistochemistry and immunofluorescence were carried out to evaluate the expression of estrogen receptor, progesterone receptor, androgen receptor (AR), EGFR, epidermal growth factor receptor 2 (HER2), and other biomarkers. Two hundred twelve (53%) cases were positive for EGFR expression, including 173 MABC and 39 non-MABC cases. EGFR expression was positively associated with AR expression in MABC, as well as with more advanced tumor stage and high Ki67 expression. Patients with EGFR expression had worse outcomes than those without. As a prognosis biomarker, EGFR was significantly associated with poorer clinical outcomes, and the co-expression of EGFR and HER2 often predicted worse outcomes in MABC. This study suggests that the identification of new targets such as HER2 and EGFR may help with assessing the prognosis of patients with MABC. Using both AR and EGFR as therapeutic targets may be especially important in MABC and may help to guide the choice of suitable treatments for individual breast cancer patients.

The immunohistochemical expression and potential prognostic value of HDAC6 and AR in invasive breast cancer

Previous studies have investigated the role of histone deacetylase 6 (HDAC6) in the regulation of androgen receptor (AR) in prostate cancer; however, the role of HDAC6 has not yet been clearly identified in breast cancer. The aim of this study was to examine the expression of HDAC6 and AR, determine the correlation between HDAC6 and AR, and assess the prognostic value of HDAC6 and AR in breast cancer. A total of 228 cases of invasive breast cancer were randomly selected. The expression of HDAC6 and AR was analyzed by immunohistochemistry. χ² Tests were performed to determine the association between conventional clinicopathological factors and HDAC6, AR, and HDAC6/AR co-expression. Spearman correlation methods were performed to determine the correlation between HDAC6 and AR, and Kaplan-Meier analyses were performed to determine the prognostic impact of HDAC6, AR and HDAC6/AR co-expression; 58.8% (134/228) patients exhibited high expression of HDAC6. High HDAC6 expression was significantly associated with high histologic grade (G3) (P<.001) and p53 overexpression (P=.002). HDAC6 and AR expression levels were significantly associated (r=0.382, P<.01). In estrogen receptor (ER)-negative samples, high expression of HDAC6 was more common in the AR+ groups (P<.001) and correlated with high histologic grade (G3) (P=.009), as well as higher HER2 (P=.006) and p53 levels (P=.012). Higher expression of AR and HDAC6 and HDAC6/AR co-expression had a worse clinical prognosis. The expression levels of HDAC6 and AR are correlated in breast cancer; moreover, HDAC6 and AR have prognostic value in predicting the overall survival (OS) of ER-negative breast cancer patients.