MicroRNAs (miRNA) are endogenous noncoding small RNAs that regulate the activity of mRNAs. Many miRNA genes, including let-7a-3, are located in CpG islands, suggesting possible epigenetic regulation of their expression. Promoter CpG island methylation of tumor suppressor genes is involved in cancer development and progression. Using real-time methylation-specific PCR and real-time reverse trans...

Spermatogenesis is a multistep synchronized process. Diploid spermatogonia differentiate into haploid spermatozoa following mitosis, meiosis and spermiogenesis. Division and differentiation of male germ cells is achieved through the sequential expression of several genes. Numerous mRNAs in the differentiating germ cells undergo post-transcriptional and translational regulation. MiRNAs are power...

Animal microRNAs (miRNAs) typically regulate gene expression by binding to partially complementary target sites in the 3' untranslated region (UTR) of messenger RNA (mRNA) reducing its translation and stability. They also commonly induce shortening of the mRNA 3' poly(A) tail, which contributes to their mRNA decay promoting function. The relationship between miRNA-mediated deadenylation and tra...

Adenosine deaminases acting on RNAs (ADARs) convert adenosine residues to inosines in primary microRNA (pri-miRNA) transcripts to alter the structural conformation of these precursors and the subsequent functions of the encoded microRNAs (miRNAs). Here we show that RNA editing by Drosophila ADAR modulates the expression of three co-transcribed miRNAs encoded by the evolutionarily conserved let-...

Coronary artery disease (CAD) is the most prevalent cause of mortality and morbidity worldwide and the number of individuals at risk is increasing. To better manage cardiovascular diseases, improved tools for risk prediction including the identification of novel accurate biomarkers are needed. MicroRNA (miRNA) are essential post-transcriptional modulators of gene expression leading to mRNA supp...

Expression of miRNAs in Neuroendocrine Neoplasms (NEN) is poorly characterized. We therefore wanted to examine the miRNA expression in Neuroendocrine Tumors (NETs), and identify their targets and importance in NET carcinogenesis. miRNA expression in six NEN primary tumors, six NEN metastases and four normal intestinal tissues was characterized using miRNA arrays, and validated by in-situ hybrid...

Chemotherapy resistance remains an important problem in the breast cancer clinic. The ability to predict the patients who would respond to a distinct therapy would help to optimize tailored treatment options. miRNAs can mediate a number of genes in response to drug-induced acute cellular stress. Several studies suggest that let-7 miRNA may be involved in the chemosensitivity of cancer cell line...

BACKGROUND The identification of additional prognostic markers to improve risk stratification and to avoid overtreatment is one of the most urgent clinical needs in prostate cancer (PCa). MicroRNAs, being important regulators of gene expression, are promising biomarkers in various cancer entities, though the impact as prognostic predictors in PCa is poorly understood. The aim of this study was ...

The let-7 family of miRNAs have been shown to control developmental timing in organisms from C. elegans to humans; their function in several essential cell processes throughout development is also well conserved. Numerous studies have defined several steps of post-transcriptional regulation of let-7 production; from pri-miRNA through pre-miRNA, to the mature miRNA that targets endogenous mRNAs ...

Elevation of the proinflammatory cytokine IL-6 has been implicated in depression; however, the mechanisms remain elusive. MicroRNAs (miRNAs) are small non-coding RNAs that inhibit gene expression post-transcriptionally. The lethal-7 (let-7) miRNA family was suggested to be involved in the inflammation process and IL-6 was shown to be one of its targets. In the present study, we report elevation...