Prof Arthur Shulkes, Dr Joseph Ischia, A/Prof Graham Baldwin, A/Prof Damien Bolton
Many cancers produce their own growth factors and receptors. Activation of the receptor by the growth factor further stimulates the tumour's growth and spread throughout the body.
The objective of this project is to determine the potential roles of a growth factor termed Gastrin Releasing Peptide (GRP) in prostate cancers. GRP is an established growth factor in certain lung and bowel cancers but little is known about its role in tumours of the prostate especially advanced cancers that are resistant to our best treatmenthormone therapy.
Our goal is to determine the expression of GRP and its receptors in prostate cancer, the ability of GRP to stimulate growth, and the potential of antagonists to modulate the growth of prostate cancer. We are using cell culture of prostate cancer, mice
with prostate cancers (xenografts), and human resected prostate cancers.
So far we have developed a new assay system for measuring different parts of the proGRP molecule and shown that cells resembling advanced prostate cancer produce more proGRP.
We have also shown which parts of the GRP molecule stimulate the growth of the prostate cancer cells. This is important as we can then develop methods to block their activity. We have made prostate cancer cells for which the GRP gene has been inactivated so that we can compare the growth of these cells with normal prostate cancer cells. Therefore, we can determine the importance of GRP in stimulating the growth of these advanced cancers with a view to the possibility of new treatments such as chemotherapy that would target GRP.
Another way to assess how important a particular gene is for the growth of a cancer is to block this gene at the DNA level. We have performed this for the proGRP gene and now seek to demonstrate that these cells behave differently to the normal cells. If we can show that these cells are less likely to behave like cancer cells then this provides evidence of the importance of proGRP in cancer development.