Which are the Genetic Basis of Cancers?
Cancer is a disease related to abnormal growth of cells where the cells have the potential to spread and invade other parts of the body. Higher growth rate leads to the formation of an undifferentiated mass of cells known as tumours in the body. The tumour generated in cancer can be a benign tumour (does not spread to other parts) or malignant tumour (spread to other parts). There are various factors that could contribute to the occurrence of cancer like environmental and genetic.
In cancer, two types of genes known as oncogenes and tumour suppressor genes are affected. The genes that promote the activity of cell growth and reproduction are known as oncogenes. They are present in an inactive state in the body. The gain of function mutation due to any mutagen activates these genes. They increase the rate of cell growth, creating tumours in the body. The RAS family of genes represents oncogenes in the body. Tumour suppressor genes work in the opposite manner to oncogenes. They function to inhibit cell growth and limit the survival of tumour cells. The mutation that causes loss of function of these genes contributes to tumour formation leading to cancer. An example of a tumour suppressor gene is the p53 gene, BRCA1 and BRCA2 gene.
Mutation can be caused due to exposure of physical or a chemical mutagen and can be a point mutation, or a base substitution. Mutation can also occur due to defect in any DNA damage repair systems of these genes.
Step by step
Solved in 3 steps
