miR-34a expression in human breast cancer is associated with drug resistance.

miR-34a is significantly down-regulated in breast cancer tissues and cell lines, which may be correlated with breast cancer multi-drug resistance (MDR). Here, we conducted cell-based experiments and clinical studies in a cohort of 113 breast cancer samples to analyze miR-34a expression and breast cancer MDR. Expression of miR-34a is down-regulated in the multi-drug resistant MDR-MCF-7 cells compared with its parental cells. Patients with miR-34a low expression had poorer overall survival (OS) and disease free survival (DFS) in comparison with those with high expression. Transfecting miR-34a mimics into MDR-MCF-7 breast cancer cells led to partial MDR reversal. Compared with the control group, miR-34a significantly reduced both the mRNA and protein expressions of BCL-2, CCND1 and NOTCH1, but no obvious changes were found in P53 or TOP-2a expression. In breast cancer tissue samples, the expression of miR-34a was related to BCL-2, CCND1 and NOTCH1, but not to HER-2, P53 and TOP-2a. Altogether, our findings suggest that miR-34a is an MDR and prognosis indicator of breast cancer, which may participate in the regulation of drug-resistant breast cancer by targeting BCL-2, CCND1, and NOTCH1.

Goiter and hearing impairment: A case of a male patient with Pendred syndrome.

Pendred syndrome is a rare genetic disease that causes a disturbance in thyroid hormone synthesis, which results in thyroid dysfunction and the development of goiter and sensorineural deafness. The present report describes the case of a young euthyroid male, who developed a large goiter and hearing impairment, despite no family history of these conditions. A left lobectomy and a subtotal right lobectomy were performed, and the patient was administered permanent hormone replacement therapy with thyroxine. Patients with Pendred syndrome exhibit distinct clinical features and the mechanisms associated with the molecular genetics of this disease have been clarified. Thus, gene detection is considered to be a reliable diagnostic method. Certain patients require surgical intervention in order to relieve the symptoms. Misdiagnosis can be significantly reduced by increasing the understanding of Pendred syndrome.