An international group of scientists from Australia and Canada are getting closer to a new treatment for prostate cancer that works by starving tumours of an essential nutrient.
Dr Jeff Holst from Sydney’s Centenary Institute, and his colleagues from Adelaide, Brisbane and Vancouver have shown they can slow the growth of prostate cancer by stopping the protein ‘leucine’ from being pumped into tumour cells.
Leucine is involved in cell division and making proteins. It ‘feeds’ cell growth by being pumped through ‘protein pumps’ on the surface of our cells.
In 2011, Dr Holst and his colleagues showed that prostate cancer cells have more ‘protein pumps’ on their surface compared with normal cells. These pumps are allowing the cancer cell to take in more leucine, thereby stimulating overactive cell division.
In a follow-up study, recently published in the Journal of the National Cancer Institute, Dr Holst and his team were able to successfully block the leucine pumps with targeted chemical compounds. As a result, they inhibited the activity of more than 100 genes which contribute to prostate cancer growth and spread.
“There are currently no drugs that target these leucine nutrient pumps, but we are working on that.” Said Dr Holst.
“We are confident we will have new compounds available for testing in the clinic in the next few years.”
Interestingly, our bodies can’t make leucine. It is an essential nutrient which comes from our diet and is transported into cells by these specialised protein pumps.
Dr Holst said, “A lot of cancers, such as prostate cancer, are actually western diseases. Really there are very low incidence rates in Asia and Africa. But when Asian or African men migrate to the US, studies have shown that they get prostate cancer at the same rate as the Caucasian American population.”
“Western diets, high in red meat and dairy products, are correlated with prostate cancer. Interestingly these foods are also high in leucine. So we are looking at how changing diet affects how cancer cells grow—and we can now investigate this impact right down to the genetic and molecular level.”
Dr Holst and his team have suggested that other solid cancers, such as melanoma and breast cancer may well be amenable to the same approach.