Brisbane researchers have discovered and partially cloned two genes that may be integral to the development of colon cancer.
The research team involved National, Health and Medical Research Council (NHMRC) senior research officer in the University of Queensland's Obstetrics and Gynaecology Department Dr Michael McGuckin, Pathology Department PhD student Stephanie Williams and Dr Toni Antalis from the Queensland Institute of Medical Research (QIMR).
They found that the complex genes, known as mucin genes, were under-expressed or absent altogether in colon cancer cells. It is possible that these genes are important regulators of normal cell growth. Dr McGuckin said the mucins' structure allowed them to bind with growth factor receptors on normal cells.
Their under-expression in colon cancer cells could pave the way for the cancer to spread, he said. It is this spread of cancer cells that causes death rather than the originating tumour.
The world-first discovery widened understanding of colon cancer development and could lead to better drugs to treat the disease, Dr McGuckin said.
"Drugs could be designed to mimic the activity of the two mucin genes, slowing or even stopping the cancer's progression," Dr McGuckin said.
He said his recent study trip to the Wellcome Trust Centre for Cell Matrix Research at the University of Manchester had revealed the genes could also be involved in the pathology of other epithelial diseases including cystic fibrosis.
Dr McGuckin has been studying the way mucins operate in cancer patients for a decade.
His research focuses on the role of the epithelial group of mucins in the occurrence and spread of ovarian, cervical, breast and colon cancer. Their presence in huge numbers or absence altogether had been shown to have a direct link to these cancers' progression, Dr McGuckin said.
He said some mucins were responsible for changes in cancer cell adhesion, allowing cells to break away from the primary tumour and take hold at another, secondary location.
His work is funded by a three-year, $340,000 NHMRC grant, a three-year, $135,000 Kathleen Cunningham Foundation grant and $85,000 a year from Australian-based medical diagnostic company, Medical Innovations Ltd.
In conjunction with Medical Innovators Ltd researchers, Dr McGuckin is developing a better blood test to monitor the progression of some cancers and gauge treatment effectiveness. The test measures mucin levels in a blood sample.
"For example, an increasing test result in a patient receiving chemotherapy may alert doctors to the fact that a patient was not responding to that particular treatment and lead to an alternative treatment being prescribed," he said.
Dr McGuckin assisted Medical Innovators Ltd to develop a diagnostic blood test for certain cancers in 1993. The test is now sold internationally, opening up an important Australian export industry.
With Professor Bruce Ward, also of the Obstetrics and Gynaecology Department, Dr McGuckin is hoping to become involved in clinical trials of a mucin-based vaccine in Queensland ovarian cancer patients.
The vaccine was developed at the Austin Research Institute in Melbourne.
If found to be effective, the vaccine could be administered to cancer patients to help their bodies raise an immune response - produce large numbers of "white blood cells" or T-cells - to destroy cancer cells.
Classified as a biological therapy, it would be a powerful and less invasive addition to the current arsenal of cancer treatments including surgery, chemotherapy and radiotherapy, Dr McGuckin said.
Ovarian cancer strikes an average of one in 100 Australian women compared to the breast cancer rate of one in 14. However, there were no screening tests for ovarian cancer and a lack of symptoms meant women were often diagnosed much later reducing long-term survival chances and limiting treatment methods to radical surgery followed by chemotherapy, Dr McGuckin said.
"Whereas around 70 percent of women remain alive five years after diagnosis of breast cancer, only between 30 and 40 percent of ovarian cancer patients make it this far," he said.
For more information, contact Dr McGuckin (telephone 07 3365 5199).
