Question

Please write down 4 main types of defects found in cancer cells, along with a brief explanation of what the long term result of that defect is for the cell. Then conclude with a statement of how the extracellular matrix plays a role in keeping normal cells under control and the means by which it does this.

Answer 1

Ans) The defects found in the cancer cells are :

1) Loss of the control on the cell cycle checkpoint mechanisms.This is the reason for their indefinite proliferation and thus they just go on dividing thereby producing tumor formation.

2) Faulty DNA damage repair mechanisms allow them to replicate and divide indefinitely.

3) Genomic instability is observed in cancer cells.Changes in chromosome numbers due to non-disjunction can result in the aneuploidy etc.The faulty cell cycle checkpoint mechanisms,faulty DNA damage repair mechanisms etc can result in the genomic instability.

4) Loss of function of pro-apoptotic genes.This results in the inhibition of apoptosis and due to this the cancer cells will just divide without having cell death by apoptosis.

ECM plays a crucial role in order to attach or adhere the normal cells.But the cancer cells secrete matrixmetalloproteases which has the ability to degrade the ECM components like fibronectin,cadherin etc as a result of which they can undergo metastasis and ultimately leads to malignant tumor formation.