Take the 2-minute tour ×
Biology Stack Exchange is a question and answer site for biology researchers, academics, and students. It's 100% free, no registration required.

How many ways can an Apoptosis mechanism be made disfunctional or irreparably damaged? If a cell has damaged Apoptosis mechanisms and it divides will its daughter cells have such damage?

share|improve this question

2 Answers 2

up vote 1 down vote accepted

Most of us have had the apoptotic process in our B-lymphocytes disrupted when we had infectious mononucleosis, caused by the EBV virus. The EBV virus (pardon the virus-virus) encodes proteins, including one that mimics a host cell protein, Bcl-2, which plays an important role in apoptosis. The set of virus 'decoy' proteins forces the infected cell to survive and be a host to produce new virus, whereas the cell's normal response would be to apoptose. Wart viruses such as HPV may have similar mechanisms.

So in summary, excessive growth or transformation to an immortal cell typically requires activation of mechanisms that promote cell growth and the inibition of mechanisms that promote cell death. "Transforming viruses' often have mechanisms to affect both cell growth and cell death.

This answer isn't to the question 'how many ways can [the] apoptosis mechanism [..] be damaged ', but answers 'what's a common way that apoptosis pathways can be disrupted'.... large DNA transforming viruses.

share|improve this answer
    
Could a transfoming virus exist that could turn on apoptosis mechanisms? You could say all cells have self-destuction mechanisms(if I'm correct) , could a cancer cell with its excessive growth still have one type of 'self-destuction'mechanism 'left-over', or could daughter cancer cells have a self-destruct ability that is presently inactive? –  user128932 Apr 15 at 6:40
    
@user128932. Could..possibly, although it would seem to be at odds with promoting growth. Yes, there are at least 2 other cell death pathways that could act if apoptosis is disrupted, but they may share common pathways and may also be disrupted. Will be cell type dependant. Daughter cells would have the same phenotype as the parent cell if they: share the same mutations (see AndroidPenguin answer), share epigenetic modifications that alter apoptotic gene expression or the virus genome (and proteins) persists. –  PlaysDice Apr 15 at 14:37
    
Do stem cells have apoptosis mechanisms? Could a stem cell having a 'self-destruction' mechanism repair the cell-death pathways in a cancer cell? –  user128932 Apr 16 at 1:36
    
@user128932 I suggest you ask that as a separate question. –  PlaysDice Apr 16 at 10:50
    
@user128932. Per the site guidelines you have the option to "accept" an answer that best addresses your question –  PlaysDice Apr 16 at 11:54

Lot's of ways. Apoptosis is complex, but falls under two pathways ending up at caspase 3. Anywhere in the pathway may there be a problem but also in things that trigger the pathway. For example in cancer there is loss of tumour suppressors which ensure a damaged cell undergoes apoptosis or prevents replication and oncogenes which allow controlled replication. Damage to these genes allows a cell to divide in the absence of signals to divide and also forget to check that it's DNA isn't damaged before replicating. This is then passed on to the daughter cancer cells. As each check is removed the cell permits more and more mutations meaning more and more likelihood for the next mutation to occur. Cancer is caused literally by one cell having defects and every daughter cell also possess the defects. Those that have defects which accidentally kill the cell are selected out.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.