Epigenetics: Mechanisms, potential roles, and therapeutic strategies in cancer progression.

Mutations or abnormal expression of oncogenes and tumor suppressor genes are known to cause cancer. Recent studies have shown that epigenetic modifications are key drivers of cancer development and progression. Nevertheless, the mechanistic role of epigenetic dysregulation in the tumor microenvironment is not fully understood.

A high AR:ERα or PDEF:ERα ratio predicts a sub-optimal response to tamoxifen therapy in ERα-positive breast cancer.

Purpose: Approximately 30% oestrogen receptor alpha (ERα)-positive breast cancer (BC) patients exhibit intrinsic or recurrent resistance to adjuvant endocrine therapy with tamoxifen. The androgen receptor (AR) is expressed in about 90% of ERα-positive patients, with particularly high expression in tamoxifen-resistant tumours. Prostate-derived Ets factor (PDEF), which is a co-regulator of AR, plays a role in tamoxifen resistance in ERα-positive BC.

Interrelation of androgen receptor and miR-30a and miR-30a function in ER, PR, AR MDA-MB-453 breast cancer cells.

The association between androgen-induced androgen receptor (AR) activating signal and microRNA (miR)-30a was investigated, as well as the function of miR-30a in estrogen receptor-negative (ER), progesterone receptor-negative (PR), and AR-positive (AR) MDA-MB-453 breast cancer cells. Androgen-induced AR activating signal upregulated the expression of AR, and downregulated the expression of miR-30a, b and c. Bioinformatics analysis indicated a putative miR-30a, b and c binding site in the 3'-untranslated region of AR mRNA.

[Value of CK5/6, CK14, ER and PR detection in differential diagnosis of intraductal proliferative lesions of the breast].

Objective: To investigate the expression of high-molecular-weight keratins CK5/6, CK14, estrogen receptor (ER) and progesterone receptor (PR) in differential diagnosis of simple ductal hyperplasia (UDH), atypical ductal hyperplasia (ADH) and low-grade ductal carcinoma in situ (low-grade DCIS) .

Methods: The clinicopathological data of twenty cases of atypical ductal epithelial hyperplasia (ADH) with focal cancerization changed into low-grade DCIS diagnosed at Tianjin Medical University Cancer Institute and Hospital between January 2013 and February 2014 were reviewed and analyzed. The expressions of CK5/6, CK14, ER and PR were detected by immunohistochemistry.

Loss of FAT1 during the progression from DCIS to IDC and predict poor clinical outcome in breast cancer.

FAT1 and β-catenin are important tumor regulatory factors. The aim of this study was to detect the possible disparity in their expression from ductal carcinoma in situ (DCIS) to invasive ductal carcinoma (IDC) and to explore its correlation with clinicopathological factors. We used immunohistochemistry to detect protein expression of FAT1 and β-catenin in breast cancer tissues from 113 cases of DCIS and 149 cases of IDC.

Clinicopathologic characteristics and molecular subtypes of microinvasive carcinoma of the breast.

Patients with microinvasive carcinoma often have favorable prognosis, but it remains unclear whether this special type of breast cancer represents a distinct morphological entity with its own biological features and clinical behavior distinct from those of ductal carcinoma in situ (DCIS). The study is a retrospective analysis of a large patient cohort from a single institution. One hundred and thirty one microinvasive carcinoma and 451 DCIS cases were collected.

Androgen receptor decreases CMYC and KRAS expression by upregulating let-7a expression in ER-, PR-, AR+ breast cancer.

It is generally known that the decision to use anti-estrogen therapy is based on the expression of estrogen and progesterone receptors in breast cancers. Recent studies have shown that androgen receptor (AR) is frequently expressed in ER-, PR- breast cancer and plays an important role in the prognosis of breast cancer patients. Furthermore, AR can increase the global expression of microRNAs, post-transcriptional gene regulators that play a crucial role in the initiation and progression of breast cancer.