An organic compound found in cruciferous vegetables such as broccoli, cabbage and cauliflower can inhibit the growth of prostate cancer cells by activating a specific gene that encodes phosphatase and tensin homolog (PTEN), a tumour-suppressing enzyme. This finding may help design novel therapies for prostate and other types of cancers1.
An international research team, including a scientist from the Intonation Research Laboratories in Hyderabad, India, set out to explore the roles of PTEN, a protein encoded by the PTEN gene in cancer.
The PTEN enzyme has been found to suppress tumours when it accumulates in the cell membrane. In cell-based experiments, the researchers identified that WWP1, a protein found in cells, disrupts the function of the PTEN enzyme by dissociating it from the membrane. This, in turn, triggered a cascade of molecular events that eventually forms invasive tumours.
They found that another gene, known as MYC, also initiates tumour growth by regulating the activity of the WWP1-coding gene. When the WWP1-coding gene was deleted, PTEN was reactivated. This inhibited the growth of cancer cells.
Next, the researchers tested whether indole-3-carbinol, an organic compound found in cruciferous vegetables, could inhibit the activity of Wwp1 , the mice counterpart of WWP1, and reactivate Pten, the counterpart of PTEN in mice.
The organic compound blocked the activity of Wwp1 and restored the function of the Pten enzyme, shrinking prostate tumours significantly in mice. The treated mice remained fit and fertile, suggesting that the compound could emerge as a safe anti-cancer drug.
1. Lee, Y. et al. Reactivation of PTEN tumor suppressor for cancer treatment through inhibition of a MYC-WWP1 inhibitory pathway. Science 364, eaau0159 (2019)