MicroRNA—implications for cancer

MicroRNAs (miRNAs) are small RNA molecules that regulate gene expression post-transcriptionally. After the discovery of the first miRNA in the roundworm Caenorhabditis elegans, these short regulatory RNAs have been found to be an abundant class of RNAs in plants, animals, and DNA viruses. About 3% of human genes encode for miRNAs, and up to 30% of human protein coding genes may be regulated by miRNAs. MicroRNAs play a key role in diverse biological processes, including development, cell proliferation, differentiation, and apoptosis. Accordingly, altered miRNA expression is likely to contribute to human disease, including cancer. This review will summarize the emerging knowledge of the connections between human miRNA biology and different aspects of carcinogenesis. Various techniques available to investigate miRNAs will also be discussed

The miR-17/92 cluster: a comprehensive update on its genomics, genetics, functions and increasingly important and numerous roles in health and disease.

The miR-17/92 cluster is among the best-studied microRNA clusters. Interest in the cluster and its members has been increasing steadily and the number of publications has grown exponentially since its discovery with more than 1000 articles published in 2012 alone. Originally found to be involved in tumorigenesis, research work in recent years has uncovered unexpected roles for its members in a wide variety of settings that include normal development, immune diseases, cardiovascular diseases, neurodegenerative diseases and aging. In light of its ever-increasing importance and ever-widening regulatory roles, we review here the latest body of knowledge on the cluster\u27s involvement in health and disease as well as provide a novel perspective on the full spectrum of protein-coding and non-coding transcripts that are likely regulated by its members

Original Article Opportunistic infection among HIV seropositive cases in Manipal Teaching Hospital

Background: Human Immunode�ciency Virus (HIV) / Acquired Immunode�ciency Syndrome (AIDS) claimed more than 22 million deaths in the past two decades. About 10,000-15,000 Nepalese are expected to die of AIDS related deaths every year in the absence of effective treatment and care. Major cause of mortality and morbidity in HIV infected people is opportunistic infection (OI). Type of pathogen(s) responsible for OI varies from region to region. Objective: This study attempts to �nd out OI among HIV seropositive patients visiting MTH, Pokhara. Results: Tuberculosis (30%) was found to be most common OI followed by candidiasis (14%). Pulmonary tuberculosis (21.14%) was more common than extra pulmonary tuberculosis (8.92%). Oral candidiasis (8.92%) was more common than oesophageal candidiasis (5.35%). Conclusion: The study �ndings indicate that immediate and strong action needs to be taken and guidelines and strategies to tackle the HIV AIDS problems are required and should be equally implemented to achieve a decline in the rate of prevalence of HIV

Widespread changes in protein synthesis induced by microRNAs

Animal microRNAs ( miRNAs) regulate gene expression by inhibiting translation and/ or by inducing degradation of target messenger RNAs. It is unknown how much translational control is exerted by miRNAs on a genome- wide scale. We used a new proteomic approach to measure changes in synthesis of several thousand proteins in response to miRNA transfection or endogenous miRNA knockdown. In parallel, we quantified mRNA levels using microarrays. Here we show that a single miRNA can repress the production of hundreds of proteins, but that this repression is typically relatively mild. A number of known features of the miRNA- binding site such as the seed sequence also govern repression of human protein synthesis, and we report additional target sequence characteristics. We demonstrate that, in addition to downregulating mRNA levels, miRNAs also directly repress translation of hundreds of genes. Finally, our data suggest that a miRNA can, by direct or indirect effects, tune protein synthesis from thousands of genes