BACKGROUND The aim of the present study was to investigate the role of microRNA (miRNA) let-7a in down-regulation of β1-adrenoceptors (β1-AR) and elucidate the underlying mechanism of chronic ischemia heart failure (CIHF) in rats. METHODS AND RESULTS CIHF model was established by occlusion of coronary artery for 4 weeks. β1-AR level was obviously down-regulated and let-7a up-regulated in the ...

Let-7 is one of the earliest discovered microRNAs (miRNAs) and has been reported to regulate self renewal and tumorigenicity of breast cancer cells. Let-7a is a member of this family and its function has not been fully characterized in breast cancer. First, total RNAs of breast cancer cells (MDA-MB-231, MCF-7), breast cancer tissues and corresponding adjacent normal tissues were extracted and u...

MicroRNA-7a/b (miR-7a/b) protects cardiac myocytes from apoptosis during ischemia/reperfusion injury; however, its role in angiotensin II (ANG II)-stimulated cardiac fibroblasts (CFs) remains unknown. Therefore, the present study investigated the anti-fibrotic mechanism of miR-7a/b in ANG II-treated CFs. ANG II stimulated the expression of specific protein 1 (Sp1) and collagen I in a dose- and ...

The relationship between the pri-let-7a-1 rs10739971 polymorphism and gastric cancer (GC) risk has been reported. However, the role of this polymorphism in the prognosis of GC remains largely elusive. Sequenom MassARRAY platform method and the polymerase chain reaction (PCR)-restriction fragment length polymorphism were used to investigate pri-let-7a-1 rs10739971 G→A in 334 GC patients. Real-ti...

Abnormal expression of let-7a microRNA (miRNA) in non-small cell lung cancer (NSCLC) cells and tissue has been previously reported. Our objective was to investigate whether let-7a miRNA is aberrantly expressed in the blood of NSCLC patients. Using real-time PCR (RT-PCR), we analyzed let-7a miRNA in archived whole blood from 65 participants, 35 of whom had NSCLC and 30 of whom did not. Using RT-...

78-[2-(2-Aminothiazol-4-yl)acetamido]-7a-methoxycephalosporins were synthesized both by acylation of the 7(3-amino-7a-methoxycephalosporin compound (VIII) and a new direct acyl-exchange reaction of 7a-methoxy-7,9-phosphoramido compound (VII). Some of these compounds (IXa, IXb) showed higher antibacterial activity than the 7a-unsubstituted compound against P-lactamase-producing strains of Serrat...

In recent years microRNAs (miRNAs) have been established as important biomarkers in a variety of diseases including cancer, diabetes, cardiovascular disease, aging, Alzheimer's disease, asthma, autoimmune disease and liver diseases. As a consequence, a variety of monitoring methods for miRNAs have been developed, including a fast and simple method for miRNA detection by exploitation of the uniq...

Let-7a is frequently downregulated in various types of human cancer including nasopharyngeal carcinoma. However, the underlying mechanism of let-7a action in nasopharyngeal carcinoma remains elusive. In this study, we show that the enhancer of zeste homolog 2 (EZH2) is a direct target of let-7a in human nasopharyngeal carcinoma cells. The inhibiti...

The p66Shc adaptor protein is an important regulator of lifespan in mammals, but the mechanisms responsible are still unclear. Here, we show that expression of p66Shc, p52Shc, and p46Shc is regulated at the post-transcriptional level by the microRNA let-7a. The levels of let-7a correlated inversely with the levels of Shc proteins without affecting Shc mRNA levels. We identified 'seedless' let-7...

Papillary thyroid carcinoma (PTC) is the most common endocrine malignancy. Increasing evidence showed that microRNAs (miRNAs) play an important role in the PTC progression. In our study, the result showed that let-7a is significantly downregulated in PTC tissues and thyroid cancer cell lines. Overexpression of let-7a suppressed PTC cell proliferation, migration and invasion. Interestingly, we f...