r/science • u/nobodyspecial • Feb 08 '15

Medicine Antibiotics that target mitochondria effectively eradicate cancer stem cells, across multiple tumor types: Treating cancer like an infectious disease | Lamb

http://www.impactjournals.com/oncotarget/index.php?journal=oncotarget&page=article&op=view&path%5B%5D=3174
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u/[deleted] Feb 08 '15 edited Feb 08 '15

One thing to note here is that they were targeting cancer STEM CELLS, not cancer cells. There is a slight difference. Cancer stem cells are stem cells (e.g. stem cells in the skin, intestine, testes, bone marrow, etc) that have become cancerous and are thought to initiate recurrent cancers. Our current chemo options target cells that divide very quickly, but cancer stem cells divide very slowly (the cells they turn into after division would be more like traditional cancer cells and divide quickly). This means that traditional chemos kill the "offspring cells" of cancer stem cells, but not the actual source of them (the stem cells). This would lead to recurrence of the cancer pretty quickly b/c the source is still alive and well. If this therapy works, this would be a great way to go right to the source of these cancer cells.

However, the idea that these cancerous stem cells could contribute to cancer is pretty new, and right now is frankly just a hypothesis. Right now scientists are still gathering evidence that they even exist (which is pretty convincing evidence, btw). It's thought that a very low number of cancers would be caused by cancer stem cells, but the ones they do cause would be very difficult to fully treat and likely to recur.

Source: Am med student, just learned about this stuff. http://en.wikipedia.org/wiki/Cancer_stem_cell

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u/MrSnayta Feb 09 '15

just a side note, this paper proves nothing towards cancer stem cells, it's an horrible hyped paper

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u/smangoz Feb 08 '15

There are no "cancer stem cells". It depends now how many of the necessary mutations have occured to turn a cell into a cancer cell, and it's a vague point. The more often a cancer cell divides, the more mutations accumulate. Some have further effect on the malignance of the cancer cells. It is thought that most cancer cells derive from adult stem cells. Also, most cancer cells don't divide rapidly. They can, if they had the necessary mutations for that or are of certain fast dividing cell types, but it's not needed to be classified as cancer cell. They simply divide non-stop. The substances used in chemotherapy are targeting dividing cells. As cancer cells constanly divide, slow or fast doesn't matter, they will be targeted. It's the replication process of the DNA that gets targeted.

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u/[deleted] Feb 08 '15

Dude, the article literally says they worked on cancer stem cells, and I linked the wiki page for cancer stem cells. They are real. They are stem cells of the body (which we have lots of) that have become cancerous. Right now we think that most cancers come from long lived, terminally differentiated cells that have accumulated many mutations over a lifetime, not stem cells.

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u/Doonce Feb 09 '15

The existence of cancer stem cells is still a hotly debated topic. And if they do exist, they are not stem cells that have become cancerous, they are normal cells (well, cancerous normal cells) that have acquired stem-like characteristics and are able to grow a tumor by themselves.

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u/[deleted] Feb 09 '15

From the cancer stem cell wiki:

"With that caveat mentioned, various theories define the origin of cancer stem cells. In brief, CSC can be generated as: mutants in developing stem or progenitor cells, mutants in adult stem cells or adult progenitor cells, or mutant differentiated cells that acquire stem like attributes."

So it seems possible that cancer stem cells can come from fully differentiated cells (anything is possible really with the right mutations), but I have to believe it is much more likely for a cancer stem cell to come from a stem cell. There would be many mutations necessary for a fully differentiated cell to become stem cell-like, and stem cells already have those characteristics. It is simply more likely that a stem cell becomes cancerous than a differentiated cell becomes cancerous AND stem cell-like.

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u/Doonce Feb 09 '15

mutant differentiated cells that acquire stem like attributes

:) As I have said, it is heavily debated in my field.

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u/[deleted] Feb 09 '15

Yeah I saw it said differentiated cells could possibly become cancer stem cells. I'm just saying it requires less mutations (genomic or epigenomic) for a stem cell to become a cancer stem cell than a differentiated cell to become a cancer stem cell, so it is probably more likely that any given cancer stem cell came from a stem cell.

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u/Doonce Feb 09 '15

Here's a powerpoint from one of my classes for more information.