Genes responsible for cancer: a review

Abstract

Cancer is a complex disease where dynamic changes in multiple genes essential for diverse molecular pathways are involved in its initiation, progression, invasion and metastasis. The genes implicated in cancer include those involved in cell cycle control, apoptosis, DNA repair, ageing and immortalization, angiogenesis and metastasis. Activation of oncogenes, inactivation of tumour suppressor genes and alterations in microRNA and other genes through sequential accumulation of mutations, combined with multiple cycles of clonal selection and evolution, facilitate the process of carcinogenesis. Disruption of about six to twelve cellular processes is required for neoplastic transformation of a cell. Many oncogenes and oncoproteins are being used as ‘tumour markers’ and ‘targets’ for cancer diagnosis, prognosis and therapy as also for the development of new anticancer drugs. In the oncology research riding on the technological advances in genomics and proteomics has resulted in the generation of molecular portraits of various cancers in individuals, thus facilitating to provide individualistic treatment options. Considerable progress has been made in producing small molecules capable of inhibiting the enzymatic activity of Abl, Kit, EGFR, and ErbB2. For cases in which the oncogene products are not enzymes, it has been much more difficult to develop new agents. The discovery of the involvement of microRNAs in the initiation and progression of human cancer may provide additional targets for anticancer treatments.