The p16INK4A pathway in cervical cancer

Abstract

The p16INK4A protein has been proposed as a biomarker in cervical cancer and pre-cancer. p16INK4A over expression is in contrast to that seen in other cancers, where locus deletion or mutation is the norm. p16INK4A is encoded on the INK4A/ARF locus, with p14ARF and p15ENK4B, on chromosome 9p21.Up regulation of p16INK4A protein in cervical cancer and pre-cancer is an indirect consequence of the activities of the High Risk HPV oncoprotein E7. The indirect correlation between p16IN4A expression and High Risk HPV infection has lead to an extensive analysis of its potential use in cervical screening. Even so, very little is known about the function of the p16INK4A protein and its role in the cell. More recently, the role of miRNAs has been under investigation in cervical cancer. miRNAs function in post transcriptional repression by the sequestration and degradation of mRNA and are therefore important in the control of gene and protein expression. Several have miRNAs been described as oncogenes and tumour suppressor genes.