For prostate cancer awareness month, we focus on the work of Dr Valentine Macaulay.
Prostate cancer is curable if diagnosed early, but incurable if there is spread away from the prostate to form secondary tumours (metastases). Metastatic prostate cancers respond initially to hormone therapy and some to radiotherapy and chemotherapy, but invariably develop resistance to treatment.
Dr Macaulay’s group discovered that a protein called Insulin-like Growth Factor Receptor (IGFR) affects how aggressively prostate cancer behaves. The more IGFR is present and active in a tumour, the harder the tumour is to treat.
IGFR is a protein bound to the surface of cells. IGFR is activated by a small hormone-like protein called Insulin-like Growth Factor (IGF), most of which is made in our livers. When IGFR is activated, it switches on other proteins inside the cell, carrying a message that encourages cells to grow. This function of IGFR plays an important role in normal growth and development.
"Microscope image of a prostate tumour. The brown colour shows the higher level of IGFR in the tumour and the location of the IGFR in the nucleus of the cancer cells."
Many cancers show excessive activation of IGFR. This encourages cancer cells to grow and spread, forming secondary tumours, and helps the cancer cells survive in the face of anti-cancer treatments.
The discovery that some prostate tumours have too much IGFR or IGFR that is hyperactive may explain why some advanced prostate tumours become resistant to therapy. Dr Macaulay’s group has also found that IGFR can move into the nucleus of cancer cells, switching on genes that help the cells to grow and move .
Dr Macaulay and her group are now working to discover more about how IGF and IGFR promote cancer development and treatment resistance, and whether blocking IGFR will restore the effectiveness of anti-cancer therapies.
Blocking IGFR has the promise to offer improved treatments for men with prostate cancer as well as patients with other tumours including breast and bowel cancers.