Final answer:
Cancer cells can proliferate without serum because of genetic mutations that override normal cell cycle controls and disable contact inhibition. They maintain telomeres with active telomerase and avoid apoptosis, leading to relentless division and potential metastasis. Treatment can involve angiogenesis inhibitors, which cut off the tumor's blood supply.
Step-by-step explanation:
Cancer cells may proliferate even when serum is not provided due to the accumulation of DNA mutations that disrupt normal cell cycle control. Unlike normal cells, which stop dividing upon forming a monolayer through contact inhibition, cancer cells lack certain cell surface proteins like gap junctions, cadherins, and integrins, preventing them from receiving signals to halt division. Uncontrolled proliferation occurs when cancer cells bypass the natural checkpoints in the cell cycle, such as those controlled by cyclin and cyclin-dependent kinases (cdk).
Moreover, due to these mutations, cancer cells often possess active telomerase, an enzyme allowing them to maintain their telomeres and continue dividing indefinitely. The evasion of apoptotic clearance also contributes to their uncontrolled growth. Ultimately, these aberrant cells can metastasize, spreading to other parts of the body.
Angiogenesis inhibitors are drugs used in cancer treatment to prevent the formation of new blood vessels that supply nutrients to tumors, thereby inhibiting their growth and potential to metastasize.