miR-638 mediated regulation of BRCA1 affects DNA repair and sensitivity to UV and cisplatin in triple negative breast cancer

Introduction Triple-negative breast cancer (TNBC) represents 15 to 20% of all types of breast cancer; however, it accounts for a large number of metastatic cases and deaths, and there is still no effective treatment. The deregulation of microRNAs (miRNAs) in breast cancer has been widely reported. We previously identified that miR-638 was one of the most deregulated miRNAs in breast cancer progression. Bioinformatics analysis revealed that miR-638 directly targets BRCA1. The aim of this study was to investigate the role of miR-638 in breast cancer prognosis and treatment. Methods Formalin-fixed, paraffin-embedded (FFPE) breast cancer samples were microdissected into normal epithelial and invasive ductal carcinoma (IDC) cells, and total RNA was isolated. Several breast cancer cell lines were used for the functional analysis. miR-638 target genes were identified by TARGETSCAN-VERT 6.2 and miRanda. The expression of miR-638 and its target genes was analyzed by real-time qRT-PCR and Western blotting. Dual-luciferase reporter assay was employed to confirm the specificity of miR-638 target genes. The biological function of miR-638 was analyzed by MTT chemosensitivity, matrigel invasion and host cell reactivation assays. Results The expression of miR-638 was decreased in IDC tissue samples compared to their adjacent normal controls. The decreased miR-638 expression was more prevalent in non-TNBC compared with TNBC cases. miR-638 expression was significantly downregulated in breast cancer cell lines compared to the immortalized MCF-10A epithelial cells. BRCA1 was predicted as one of the direct targets of miR-638, which was subsequently confirmed by dual-luciferase reporter assay. Forced expression of miR-638 resulted in a significantly reduced proliferation rate as well as decreased invasive ability in TNBC cells. Furthermore, miR-638 overexpression increased sensitivity to DNA-damaging agents, ultraviolet (UV) and cisplatin, but not to 5-fluorouracil (5-FU) and epirubicin exposure in TNBC cells. Host cell reactivation assays showed that miR-638 reduced DNA repair capability in post UV/cisplatin-exposed TNBC cells. The reduced proliferation, invasive ability, and DNA repair capabilities are associated with downregulated BRCA1 expression. Conclusions Our findings suggest that miR-638 plays an important role in TNBC progression via BRCA1deregulation. Therefore, miR-638 might serve as a potential prognostic biomarker and therapeutic target for breast cancer

miR-671-5p inhibits epithelial-to-mesenchymal transition by downregulating FOXM1 expression in breast cancer.

MicroRNA (miRNA) dysfunction is associated with a variety of human diseases, including cancer. Our previous study showed that miR-671-5p was deregulated throughout breast cancer progression. Here, we report for the first time that miR-671-5p is a tumor-suppressor miRNA in breast tumorigenesis. We found that expression of miR-671-5p was decreased significantly in invasive ductal carcinoma (IDC) compared to normal in microdissected formalin-fixed, paraffin-embedded (FFPE) tissues. Forkhead Box M1 (FOXM1), an oncogenic transcription factor, was predicted as one of the direct targets of miR-671-5p, which was subsequently confirmed by luciferase assays. Forced expression of miR-671-5p in breast cancer cell lines downregulated FOXM1 expression, and attenuated the proliferation and invasion in breast cancer cell lines. Notably, overexpression of miR-671-5p resulted in a shift from epithelial-to-mesenchymal transition (EMT) to mesenchymal-to-epithelial transition (MET) phenotypes in MDA-MB-231 breast cancer cells and induced S-phase arrest. Moreover, miR-671-5p sensitized breast cancer cells to cisplatin, 5-fluorouracil (5-FU) and epirubicin exposure. Host cell reactivation (HCR) assays showed that miR-671-5p reduces DNA repair capability in post-drug exposed breast cancer cells. cDNA microarray data revealed that differentially expressed genes when miR-671-5p was transfected are associated with cell proliferation, invasion, cell cycle, and EMT. These data indicate that miR-671-5p functions as a tumor suppressor miRNA in breast cancer by directly targeting FOXM1. Hence, miR-671-5p may serve as a novel therapeutic target for breast cancer management

Thoracoscopic Resection of Multiple Müllerian Cysts.

© 2015 The Society of Thoracic Surgeons. Müllerian cysts in the mediastinum were first described by Hattori in 2005 [1]. We report the first known case of multiple müllerian cysts in the thorax in a 35-year-old woman with cough and an abnormal chest roentgenogram. Multiple bilateral cysts were resected thoracoscopically. Histologic examination showed benign ciliated tubal epithelium that stained positive with immunohistochemical stains for estrogen receptor (ER), cancer antigen 125 (CA-125), Wilms\u27 tumor protein 1 (WT-1), and paired box gene 8 (PAX8), confirming müllerian origin. We also review the embryogenesis and pathologic characteristics of müllerian cysts and the rare occurrence of their migration to the thorax

Noninvasive carcinoma ex pleomorphic adenoma of the parotid gland: A difficult diagnosis on fine needle aspiration.

Carcinoma ex pleomorphic adenoma (CXPA) is a rare epithelial malignancy that arises from a primary or recurrent pleomorphic adenoma (PA). It may be noninvasive (NI) or invasive. NI CXPA is extremely rare. Preoperative diagnosis on fine needle aspiration (FNA) of CXPA may be difficult and poses a diagnostic challenge to clinicians and pathologists. Herein, we describe the FNA findings of a case of NI-CXPA. A 69-year-old woman presented with rapid enlargement of a stable parotid mass of 25 years. Cytologically, malignant cells were focally associated with metachromatic fibromyxoid matrix that was homogeneous and dense with a vague fibrillary quality. There were cell groups, papillary-like clusters and single malignant cells. The nuclei were pleomorphic with irregularly dispersed chromatin, and the cytoplasm was ill-defined and granular. Nucleoli were small to inconspicuous. Mitoses and necrosis were not seen. Cytological features were not specific for any type of salivary gland carcinoma. The FNA diagnosis was primary high-grade adenocarcinoma of the parotid gland, not otherwise specified. Facial nerve-sparing total parotidectomy was performed, which histologically showed PA interspersed with ducts and nests composed of pleomorphic atypical nuclei surrounded by extensive hyalinization. Single cells were also noted. No capsular infiltration was seen in the entirely sampled tumor. Immunohistochemistry for Ki-67 showed a higher proliferation rate in the malignant ducts and p63 positive cells focally surrounded some of the malignant ducts. Histological diagnosis was NI-CXPA. Accurate diagnosis is important for proper surgical management; however, the preoperative diagnosis of NI-CXPA is difficult to make on FNA

Rescreening Practices of Negative Papanicolaou Tests With Positive Human Papillomavirus Test Result

CONTEXT.—: The yield of the prospective rescreening process for negative for intraepithelial lesion or malignancy (NILM) Papanicolaou (Pap) tests is higher with the inclusion of a greater proportion of high-risk cases. One of the suggested criteria for classifying a Pap test finding as high risk is recent or concurrent high-risk human papillomavirus (HPV) positivity. OBJECTIVE.—: To evaluate how the results of HPV testing have been incorporated in the prospective rescreening of NILM Pap tests across a wide range of laboratories. DESIGN.—: A questionnaire survey was sent to laboratories participating in the 2019 College of American Pathologists (CAP) Gynecologic Cytology (PAP Education) Program. RESULTS.—: Of the 1507 participating laboratories, 667 (44%) responded to the survey. Most laboratories (59.4%; 396 of 667) had not incorporated HPV test/genotyping results to select NILM Pap tests for rescreening. Amongst the remaining laboratories, for NILM HPV-positive Pap test results, 112 (16.8%) had a policy to rescreen by a cytotechnologist only, 51 (7.6%) by a pathologist only, and 86 (12.9%) by both. Of 264 laboratories, 181 (68.6%) reported the cytology upon availability of the HPV test result and completion of the secondary review. Of 661 laboratories, 145 (21.9%) included consensus-type recommendations in the cytology report for such Pap tests. CONCLUSIONS.—: This CAP survey provides significant information regarding the current trends in the use of HPV test results in prospective rescreening of NILM Pap tests. Future studies on quality improvement can further assist in the standardization of this process across different laboratories