Biochemical and Molecular Biological Studies on Oral Cancer: An Overview

ABSTRACT

Oral cancer is the cancerous tissue growth located in the oral cavity. It may arise as a primary lesion originating in any of the oral tissues, by metastasis from a distant site of origin, or by extension from a neighboring anatomic structure, such as the nasal cavity or the maxillary sinus. Smoking and other tobacco use are associated with about 75 percent of oral cancer cases. Alcohol use is another high-risk activity associated with oral cancer. Infection with human papillomavirus (HPV), particularly type 16 (there are over 120 types), is a known risk factor and independent causative factor for oral cancer. Oncogenes, gain-of-function mutations of highly regulated normal cellular counterparts (proto-oncogenes), are likely involved in the initiation and progression of oral neoplasia. Cellular oncogenes were initially discovered by the ability of tumor cell DNA to induce transformation in gene transfer assays. Mechanisms of activation of these cellular oncogenes include point mutations and DNA re-arrangements. Several of these cellular oncogenes are homologs of retroviral oncogenes (e.g., the ras genes); others are new oncogenes. Tumor suppressor genes or anti-oncogenes have been documented to confer potent negative regulatory controls which are lost due to chromosomal alterations during tumor formation. Functional loss of multiple tumor suppressor genes is believed to be the major event leading to the development of malignancy. Treatment is done till date with the help of radiation therapy, considering the removal of tumor which proceeds with the surgery. Chemotherapy is also used but not to a wide extent and that too has to be done with radiation and research work is still going on the drug discovery for this disease, hence looking towards this fact we opted for the work in this area looking into the successful way of the treatment for oral cancer. The present review is compilation of the data pertaining to biochemistry and molecular biology of oral carcinoma and would certainly provide new insights to explore the development of nutraceuticals based on the hypothesis projected by future studies on computational biotechnology of oral carcinoma.