Answer:
Some of the factors that might cause unregulated cell cycle are-
- Genetic mutation
- Growth factors
- inactivation of tumor suppressor gene
- Disregulation of cell cycle check points
- Oncogenic retroviruses.
Explanation:
1. Genetic Mutation- mutation in the proto-oncogenes can turn them into oncogenes which stimulate cell division. Some common causes of genetic mutation are radiations, chemical agents called mutagens, etc.
2. Growth factors- these are the molecules that bind to receptor proteins to initiate a signaling pathway that can result in cell cycle.
3. Tumor suppressor genes- these are the genes responsible for stopping the cell to enter cell cycle. Inactivation of these genes can cause unregulated cell division.
4. Cell cycle checkpoints - during the cell cycle, a cell has to pass through certain checkpoints which make sure the continuity or stopping of the process. Problem in their regulation can cause uncontrolled cell division.
5. retroviruses- These are the viruses who have RNA as their genetic material instead of DNA. They replicate via DNA intermediate which when they insert inside a cell can start cell cycle.
