Oncogene and Tumor Suppressor Gene

Abstract

It is widely accepted that genetic alterations have causative roles for the development of human cancer. Recent advance in molecular biology has made it possible to clarify the process of stepwise accumulation of genetic alterations during tumor progression. Such genetic alterations are roughly classified into two groups ; "activation of oncogene " and "inactivation of tumor suppressor gene". In the past 10 years, more than 50 oncogenes and several candidate tumor suppressor genes have been cloned. Oncogenes are activated by several molecular mechanisms, including point mutation, amplification and rearrangement, while tumor suppressor genes are inactivated by loss and mutation. Tumor type specificity and/or association with staging of these alterations have been observed. Determination of pathogenetic and biological significance of these genetic alterations will help us to understand the molecular mechanisms of a diversity in the behavior of tumor cells.