Sydney (Australia): Researchers at the Centenary Institute have discovered a potential future treatment for prostate cancer—through starving the tumour cells of an essential nutrient they need to grow rapidly. Their work, with human cells grown in the lab, reveals targets for drugs that could slow the progress of early and late stage prostate cancer.
Each year about 3,300 Australian men die of prostate cancer. It’s Australia’s second worst cancer killer for men, matching the impact of breast cancer on women.
Current therapies for prostate cancer include surgical removal of the prostate, radiation, freezing the tumour or cutting off the supply of the hormone testosterone – but there are often side-effects including incontinence and impotence.
Growing cells need an essential nutrient, the amino acid called leucine, which is pumped into the cell by specialised proteins. And this could be prostate cancer’s weak link.
Dr Jeff Holst and his team at the Centenary Institute found that prostate cancer cells have more pumps than normal. This allows the cancer cells to take in more leucine and outgrow normal cells.
“This information allows us to target the pumps – and we have tried two routes. We found that we could disrupt the uptake of leucine firstly by reducing the expression amount of the protein pumps, and secondly by introducing a drug that competes with leucine. Both approaches slowed cancer growth, in essence ‘starving’ the cancer cells,” says Dr Jeff Holst.
First author Dr Qian Wang says by targeting different sets of pumps, the researchers were able to slow tumour growth in both the early and late stages of prostate cancer. “In some of the experiments, we were able to slow tumour growth by as much as 50 per cent. Our hope is that we could develop a treatment that slows the growth of the cancer so that it would not require surgical removal. If animal trials are successful over the next few years then clinical trials could start in as little as five years,” he says.
Dr Jeff Holst says one of the other spin-offs of the discovery is a better understanding of the links between prostate cancer and eating foods high in leucine. “Diets high in red meat and dairy are correlated with prostate cancer but still no one really understands why. We have already begun examining whether these pumps can explain the links between diet and prostate cancer.”
“Given one in nine men in Australia may develop prostate cancer in their lifetime, this discovery could touch thousands of lives,” adds Dr Jeff Holst.