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

  • $\begingroup$ 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 '14 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 '15 at 5:21

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


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

  • $\begingroup$ quite a complete figure.. i like it.. $\endgroup$ – WYSIWYG Apr 30 '14 at 10:52
  • $\begingroup$ Thanks. It is a slightly different perspective to your figure. $\endgroup$ – Chris Apr 30 '14 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 '14 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 '14 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 '14 at 4:51

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