SINGAPORE: Researchers at the National University of Singapore Yong Loo Lin School of Medicine, A* STAR (Agency for Science, Technology and Research) and the Institute of Molecular and Cell Biology have identified another gene linked to colon cancer.

This discovery could pave the way for new forms of therapy and screening processes.

For decades, scientists worldwide thought that the key cause of colon cancer is when a tumor suppressor gene called APC is disrupted, leading to the production of bete-catenin and TCF4, which causes cancer.

But now, researchers in Singapore have discovered another gene critical to the development of early stage colon cancer. This gene, called RUNX3, is the body's mechanism that gets rid of abnormal cells.

Its inactivity or absence has led to the development of 90 per cent of colon cancer cases studied by the researchers.

RUNX3 works by inhibiting the uncontrolled growth of bete-catenin and TCF4. Recently it has also been suggested that RUNX3 is involved in other cancers such as breast, lung, liver, pancreatic and colorectal cancers.

Colon cancer has overtaken lung cancer as the leading cause of death among males in Singapore. It is the second leading cause of cancer-related deaths among females.

The discovery of the RUNX3 gene means that researchers can now start work on a diagnostic test kit to aid in the cancer screening process. This discovery also paves the way for a new form of therapy which could work by targeting a malfunctioning RUNX3 gene.

The APC, on the other hand, cannot be reactivated after its disruption on a molecular level.

Professor Yoshiaki Ito, director, Oncology Research Institute, National University of Singapore, said: "There is a way to correct it, so the gene can be reactivated, then function as a tumour suppressant."

Such specific gene therapy could yield better treatment results since it is more precise than current approaches. For example, radiotherapy and chemotherapy are not gene specific and good cells could also be damaged during the process of treatment.

Professor John Wong, director, National University Cancer Institute, said: "This is the way in which we think we can address the rising healthcare costs, in trying to understand firstly, what is happening at the molecular level which is causing the disease to happen?

"How do you then design a drug to come in and intervene at the molecular level, specifically for specific switches? Turning off or turning on the molecular target, as need be, becomes something which the patient definitely benefits from.

"You can then make very informed decisions about the cost benefit as well as the risk benefit, because you know that the chances of the drug working are extremely high because you have identified the target that it goes after."

The research team will be working with the National University Hospital more closely for the next phase of research. - CNA/vm