A Micro-RNA Connection in BRafV600E-Mediated Premature Senescence of Human Melanocytes

Recent high-throughput-sequencing of the cancer genome has identified oncogenic mutations in BRaf genetic locus as one of the critical events in melanomagenesis. In normal cells, the activity of BRaf is tightly regulated. Gain-of-function mutations like those identified in melanoma frequently lead t...

Full description

Saved in:
Bibliographic Details
Main Authors: Gang Ren, Jingwei Feng, Ila Datar, Aaron H. Yeung, Srinivas Vinod Saladi, Yongqing Feng, Ivana de la Serna, Kam C. Yeung
Format: Article
Language:English
Published: Wiley 2012-01-01
Series:International Journal of Cell Biology
Online Access:http://dx.doi.org/10.1155/2012/913242
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Recent high-throughput-sequencing of the cancer genome has identified oncogenic mutations in BRaf genetic locus as one of the critical events in melanomagenesis. In normal cells, the activity of BRaf is tightly regulated. Gain-of-function mutations like those identified in melanoma frequently lead to enhanced cell-survival and unrestrained growth. The activating mutation of BRaf will also induce the cells to senesce. However, the mechanism by which the oncogenic BRaf induces the senescent barrier remains poorly defined. microRNAs have regulatory functions toward the expression of genes that are important in carcinogenesis. Here we show that expression of several microRNAs is altered when the oncogenic version of BRaf is introduced in cultured primary melanocytes and these cells undergo premature cellular senescence. These include eight microRNAs whose expression rates are significantly stimulated and three that are repressed. While most of the induced microRNAs have documented negative effects on cell cycle progression, one of the repressed microRNAs has proven oncogenic functions. Ectopic expression of some of these induced microRNAs increased the expression of senescence markers and induced growth arrest and senescence in primary melanocytes. Taken together, our results suggest that the change in microRNA expression rates may play a vital role in senescence induced by the oncogenic BRaf.
ISSN:1687-8876
1687-8884