Final answer:
The transformation into a cancerous cell involves mutations in tumor suppressor genes and proto-oncogenes, accumulation of mutations, and the inactivation of DNA repair mechanisms. Proto-oncogenes regulate cell division and, when mutated, become oncogenes that promote unrestricted cell division. Tumor suppressor genes prevent growth of abnormal cells, but when mutated, they fail to do so, facilitating cancer development.
Step-by-step explanation:
The Process of a Cell Becoming Cancerous
Cancer arises from a multi-stage process involving the accumulation of genetic damage to cells. This process is highly complex, but at its core, cancer is caused by uncontrolled cell division. The steps leading to a cell becoming cancerous typically include:
- Mutations in a tumor suppressor gene, which normally prevent cells with damaged DNA from dividing.
- Acquisition of additional mutations that may lead to the inactivation of DNA repair genes, further allowing mutations to accumulate.
- Conversion of proto-oncogenes into oncogenes due to mutations, which promote cell division.
- Inactivation of several other tumor suppressor genes that would usually inhibit cell division.
Ultimately, a series of mutations in both tumor suppressors and proto-oncogenes leads to the transformation of a normal cell into a cancer cell.
Difference Between Proto-oncogenes and Tumor Suppressor Genes
Proto-oncogenes are genes that normally help regulate cell growth and division. When these genes are mutated, they can become oncogenes that drive the cell to divide uncontrollably.
Tumor suppressor genes, on the other hand, function to restrain cell growth and division, ensuring that cells with damaged DNA do not continue to divide. Mutant tumor suppressors lose this ability, contributing to the development of cancer.