7
$\begingroup$

Has there ever been incidences of one or more cancerous cells having all it's cell-death pathways and apoptosis mechanisms intact and functional?

$\endgroup$
2
  • $\begingroup$ Are any apoptosis mechanisms in a cell that are not functioning or suppressed or damaged a typical sign of a cancerous cell? $\endgroup$
    – user128932
    Oct 18, 2014 at 4:55
  • $\begingroup$ Could something be used to cause a mutation in a cancer cell that is 'noticeable' to the immune system? $\endgroup$
    – 201044
    Mar 29, 2015 at 5:21

2 Answers 2

5
$\begingroup$

Usually the cell death mechanisms are overridden and therefore oncogenesis. The pathway components themselves are not mutated. One classical case I can cite is that of Ras-oncogene. See this article for details. Usually the survival/growth signals (MAP-kinase) are activated with simultaneous inactivation of apoptotic regulators (Akt-pathway). A mutation of MAP-kinase component ERK can also cause cancer but apoptosis is nonetheless supressed because of the interconnections of these tow pathways in the gene regulatory network.

Whereas in the case of tumor suppressors, the cause of cancer is genomic instability and failure to initiate apoptosis.

enter image description here

$\endgroup$
3
$\begingroup$

This is pretty unlikely, since one of the most important steps for cancer cells is to shut off apoptosis and proteins which control it (like p53, BCL2 and so on). Cancer cells (especially when they are genetically unstable) acquire so much mutations and misregulations, that these would otherwise trigger apoptosis which would result in the removal of the cell.

This can look like the following (figure taken from here), when you compare normal and cancer cell:

enter image description here

$\endgroup$
19
  • $\begingroup$ quite a complete figure.. i like it.. $\endgroup$
    – WYSIWYG
    Apr 30, 2014 at 10:52
  • $\begingroup$ Thanks. It is a slightly different perspective to your figure. $\endgroup$
    – Chris
    Apr 30, 2014 at 14:11
  • $\begingroup$ Does a pre-cancerous cell shut off apoptosis and the proteins that control it before it becomes a cancer cell or is it the case a cancer cell shuts off apoptosis mechanisms after it is already cancerous? $\endgroup$
    – user128932
    May 1, 2014 at 2:00
  • $\begingroup$ Usually apoptosis is affected in a later stage of oncogenesis. However, in case of DNA damage induced oncogenesis, there is a failure to initiate apoptosis when the DNA is damaged and not repaired. In this case the signal has not yet reached the apoptotic pathway. This ensues genomic instability which may further lead to uncontrolled growth i.e cancer (as you can imagine, to grow and multiply maximally is the first instinct of any lifeform) $\endgroup$
    – WYSIWYG
    May 1, 2014 at 4:35
  • $\begingroup$ Is there some way to detect if a cells apoptosis mechanisms have been shut down or made to malfunction? If so could this be a way to detect if a cell is cancerous? $\endgroup$
    – user128932
    Oct 18, 2014 at 4:51

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .