Miracle Cure?

Posted Apr 26, 2014 14:58 UTC (Sat) by nix (subscriber, #2304)
In reply to: Miracle Cure? by mpr22
Parent article: A note from your editor

Oh gods I just looked at that. They're trying to use a cyanide against cancer cells? Cyanides work by stalling the electron transport chain in mitochondria (almost literally a sort of cellular suffocation, since the net effect is that oxygen is no longer usable as an electron acceptor: the rest of the chain still works fine but is clogged with electrons with nowhere to go); cancer cells live in relatively hypoxic conditions and are strongly selected for use of fermentation instead. It is not unheard of for cancer cells to have entirely dysfunctional mitochondria, which not so coincidentally suppresses apoptosis as well, also something beneficial to a cancer cell. Such cells wouldn't even *notice* a nice dose of cyanide.

So if this thing worked it would preferentially poison *normal* cells and leave cancer cells largely untouched: just what you don't want.

Miracle Cure?

Posted Apr 26, 2014 23:56 UTC (Sat) by mathstuf (subscriber, #69389) [Link] (3 responses)

Hm. I thought cyanide worked by replacing oxygen in the red blood cells (due to similar geometry) but not being able to be removed thereby causing asphyxiation. Or is this just a second way cyanide kills?

Miracle Cure?

Posted Apr 27, 2014 2:07 UTC (Sun) by mjg59 (subscriber, #23239) [Link] (2 responses)

Carbon monoxide will bind with haemoglobin sufficiently strongly to prevent oxygen from binding, which sounds like what you're thinking of

Miracle Cure?

Posted Apr 27, 2014 4:59 UTC (Sun) by viro (subscriber, #7872) [Link] (1 responses)

That, or a confusion with methaemoglobin. That one *does* bind cyanide, but that's actually a mechanism of an antidote, not poisoning (amyl nitrite leads to conversion of hb to methb and methb binds cyanide stronger than cytochrome c).

Miracle Cure?

Posted May 2, 2014 18:40 UTC (Fri) by Wol (subscriber, #4433) [Link]

I can't remember exactly what it is, but when working with cyanide people usually have a simple antidote to hand. Iirc, it's two simple solutions which, when mixed, form some ferrOUS chemical. You can't keep it pre-mixed because it oxidises to ferrIC.

Swallow that, and it preferentially binds cyanide and takes it out of circulation for you.

Cheers,
Wol

Miracle Cure?

Posted May 8, 2014 0:38 UTC (Thu) by yodermk (subscriber, #3803) [Link] (1 responses)

I don't understand all the biology of it, but Griffin's claim is that there is an enzyme that releases the cyanide *right at the point of* the cancer cells, and another enzyme that prevents it from killing other cells.

Very fascinating, if true ...

Miracle Cure?

Posted May 8, 2014 3:10 UTC (Thu) by Cyberax (✭ supporter ✭, #52523) [Link]

Which enzyme? We know quite a lot of them pretty well by now and it'll take a very unusual enzyme to reversibly bind cyanide ions and release them in tumor cells.

Besides, tumor cells are much less sensitive to cyanide (it's even sometimes used in lab to kill healthy cells in cell cultures) because they preferably use anaerobic metabolism.

Normal cells are pretty much hardened against cyanide and can de-toxify in one hour a dose that can be lethal if administered momentarily. http://en.wikipedia.org/wiki/Thiosulfate_sulfurtransferase enzyme is used for it and it's rate-limited by the availability of sulfurous acceptors.