Glucose or Glutamine?
I was confused? One report says glucose, the other says NOT glucose but the amino acid glutamine is what melanoma lives on.
These are the two articles that seemed like a conflict to me:
I decided to ask the expert and see if he will answer me?
He kindly responded first thing! So I thought I would post his answer for others to read. Thank you Jeff!
The statement in the article that confused me was " Unlike normal cells, melanoma and other cancer cells rely on the amino acid glutamine instead of glucose for the energy" Which in my mind implied that melanoma does not use glucose at all!
I emailed the scientist named in the article on glutamine and below is his answer:
There are many different ways to "starve" a cancer - and it seems that either glucose or glutamine can do the trick. The picture is a very simple version I found showing that glucose and glutamine have many common pathways through energy generation in the TCA cycle and breakdown into lipids, amino acids and nucleotides. Therefore blocking either will have similar effects on the cancer cell.
However, it is a very complex balance, and certainly our work has only been done in the lab, not in any animal models or humans, so we still have a way to go to fully understand whether we can target these pathways. Interestingly we have also shown that blocking another amino acid, leucine, can slow prostate cancer cells - again adding to the complexity, but showing that there are a number of nutrient that are critical for cancer cells.
The key word in the statement is energy - glucose is used more for the generation of other molecules in cancer rather than in normal cells where energy generation is key, and instead glutamine is pulled in and used for energy generation in cancer cells. So they are both critical for the cells, but it is just a switch in their "normal" roles. But under certain conditions and in different tumours, this can be different, and we are still a way off finding out what mediates these differences (although as you can see, glucose is important in the BRAF mutant tumours according to the other study). We saw no difference for glutamine in either BRAF mutant or normal BRAF tumours in our study though.
JEFF HOLST, PhD
Head, Origins of Cancer Laboratory
Thanks so much Jeff! You are awesome!!!!