Question

Are tumor suppressor or oncogenes likely to be linked to genetic factors? Please explain how these two types of cancer-causing genes lead to cancer in context of genetic causes.

Answer 1

A tumor suppressor gene ( like p53 ) usually controls the cell proliferation and acts a guardian for the proper functioning of the cell. If a mutation happens in this gene in such a way that the activity is lost, uncontrollable cell proliferation will happen which is a characteristic feature of cancer cells.

An oncogene is a gene which is involved in the advancement of cell survival and proliferation but got mutated so that its activity got upregulated.

Mutations in both of genes are genetic which means they are passed to the progeny through gametes. If a mutation happens in tumor suppressor gene , (in most cases recessive mutations) leads to the loss of activity of the gene. This mutation exist in the genome and is passed to the gametes by meiosis. Suppose of the father has got the mutation, the progeny will have this mutaion in one of the homologous chromosomes. If an another mutation happens in the copy of the gene in other chromosome, it leads to the loss of function of the gene and helps for the cancer causing genes to be upregulated.

In the case of oncogenes, mutations which causes upregulation of these genes are passed to the progeny through gametes and leads to the formation of various types of cancers in the progeny.