The Role OF DNA Polymerases in Carcinogenesis

The major role of various types of DNA polymerases is genome replication. However, DNA polymerases are also necessary to establish the accuracy, efficiency of replication, repairing process, and consequently decrease in mutations induced by DNA-damaging agents. Cancer initiation is usually associated with induction of mutations in specific oncogenes or tumour suppressor genes by endogenous or exogenous genotoxic agents. Various point mutations occurring in cancer cells arise from error-generating activities of DNA polymerases. Published data show that decrease in the accuracy of DNA polymerases, without affecting their activity, could be the causative agents of tumors. It has also been reported in literature that the expression of DNA polymerases is altered in human cancers compared to normal tissue. In this review, we discuss some evidences of the role of various DNA polymerases in cancer development. The results of this study showed that lack of proper activity of DNA polymerases causes tumors through increase in the number of generated mutations in the genome. Attitude towards the function of these enzymes can result in new achievements for cancer prevention, diagnosis and treatment.