title: Upregulation of miR-23a-27a-24-2 cluster induces caspase-dependent and -independent apoptosis in human embryonic kidney cells.
abstract: miRNAs have emerged as important players in the regulation of gene expression and their deregulation is a common feature in a variety of diseases, especially cancer. Currently, many efforts are focused on studying miRNA expression patterns, as well as miRNA target validation. Here, we show that the over expression of miR-23a approximately 27a approximately 24-2 cluster in HEK293T cells induces apoptosis by caspase-dependent as well as caspase-independent pathway as proved by the annexin assay, caspase activation, release of cytochrome-c and AIF (apoptosis inducing factor) from mitochondria. Furthermore, the over expressed cluster modulates the expression of a number of genes involved in apoptosis including FADD (Fas Associated protein with Death Domain). Bioinformatically, FADD is predicted to be the target of hsa-miR-27a and interestingly, FADD protein was found to be up regulated consistent with very less expression of hsa-miR-27a in HEK293T cells. This effect was direct, as hsa-miR-27a negatively regulated the expression of FADD 3'UTR based reporter construct. Moreover, we also showed that over expression of miR-23a approximately 27a approximately 24-2 sensitized HEK293T cells to TNF-alpha cytotoxicity. Taken together, our study demonstrates that enhanced TNF-alpha induced apoptosis in HEK293T cells by over expression of miR-23a approximately 27a approximately 24-2 cluster provides new insights in the development of novel therapeutics for cancer.
authors.affiliation: Institute of Genomics and Integrative Biology, Delhi, India.
authors.forename: Ravindresh
authors.initials: R
authors.lastname: Chhabra
authors.forename: Yogita K
authors.initials: YK
authors.lastname: Adlakha
authors.forename: Manoj
authors.initials: M
authors.lastname: Hariharan
authors.forename: Vinod
authors.initials: V
authors.lastname: Scaria
authors.forename: Neeru
authors.initials: N
authors.lastname: Saini
mesh_terms: D000818:Animals; D017209:Apoptosis; D020169:Caspases / Q000378:metabolism*; D002460:Cell Line; D045744:Cell Line, Tumor; D045304:Cytochromes c / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D007668:Kidney / Q000166:cytology / Q000196:embryology*; D008564:Membrane Potentials; D035683:MicroRNAs / Q000096:biosynthesis* / Q000378:metabolism*; D051381:Rats; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015854:Up-Regulation
chemical_list: C543845:MIRN24 microRNA, human; C531388:MIRN27 microRNA, human; D035683:MicroRNAs; D014409:Tumor Necrosis Factor-alpha; D045304:Cytochromes c; D020169:Caspases