New target for cancer treatment discovered

Researchers in the US have found a novel way to target cancer. Published in the journal Cell last week, the findings of a multi-institutional research team reveal that targeting a specific group of enzymes known as Type 2 PIP kinases can prevent the growth of cancers that have a mutation in the tumour suppressor protein, p53.

This protein, also known as ‘the guardian of the genome,’ is normally involved in repairing damaged DNA and sending cells down a pathway to cell death if the damage is irreparable. Due to its anti-cancer nature, p53 is mutated in up to half of all tumours. Although normal cells do not need Type 2 PIP kinases for growth, if a cancerous cell has a p53 mutation or deletion, it becomes dependent on these enzymes. When scientists suppress these enzymes in mice with p53-defective cancers, survival rates increase significantly.
Although researchers have not yet tested the technique on humans, the inhibition of these enzymes is an attractive concept, as deleting the Type 2 PIP kinases has “essentially no effect on cell survival” in normal human cells and in mice, according to the lead author, Dr. Lewis Cantley, from the Weill Cornell Medical College. This specialised targeting of cancer cells is important as it decreases the risk that inhibitors will be toxic or have off-target effects.

This research also shows that a specific subset of breast cancer may benefit from this treatment, including HER2-positive breast cancers, which are among the most aggressive and common, with up to 1 in 4 breast cancers being HER2-positive. Now begins the arduous task of developing safe and efficient drugs to inhibit these kinases.

Dr. Cantley remains optimistic. “Well-designed Type 2 PIP kinase inhibitors may turn the tide on p53 mutant cancers. This would likely be a very powerful advance in the treatment of many cancers.”
Further information at: http://weill.cornell.edu/news/releases/wcmc/wcmc_2013/11_07a_13.shtml