An enzyme with the capacity to suppress cancer growth

Abnormal cells courtesy of Centre for Cancer Biology

Abnormal mutant cells (Caspase-2 deficient) in the right panel.

Cancer researchers at the Centre for Cancer Biology (CCB), an alliance between the University of South Australia and SA Pathology, have discovered a new aspect of cancer biology that may help to battle the spread and growth of tumours.

The research focuses on aneuploidy cells, which are often associated with abnormal chromosome content and cell division – and how an enzyme known as caspase-2, initially discovered by the lead researcher 25 years ago, can act to prevent their growth.

The research team, led by Professor Sharad Kumar and Dr Loretta Dorstyn, have discovered that caspase-2, which is found in all mammals, has the capacity to suppress cancer growth by working to destroy aneuploid cells.

“Aneuploidy is a term that describes the abnormal chromosome content of a cell and occurs when there are failings during the normal division of a cell,” Prof Kumar said.

“Aneuploidy is a feature of the majority of human tumours and is known to lead to chromosomal instability that can promote cancer onset and progression and cause drug resistance.”

In two recent publications, the team demonstrated that cells that have a deletion in the caspase-2 gene are deficient in the cell division “checkpoints” that normally prevent damaged cells from surviving and becoming aneuploid.

Their research also shows that bone marrow cells that lack caspase-2, accumulate many of these defective, potentially cancer causing aneuploid cells with age.

“This research establishes that caspase-2 is necessary to prevent the long-term survival and uncontrolled growth of aneuploid cells that could otherwise become tumorigenic,” Prof Kumar said.

“The research has provided many clues on the molecular basis of preventing aneuploidy and tumour onset and identifies caspase-2 protein levels as a potential biomarker for cancer prognosis.”

“Understanding how cells become tumorigenic and how tumours evade normal “stop growth” and “cell death” checkpoint signals, is fundamental in cancer treatment and our search for new cancer therapies”, Dr Dorstyn said.

The research was recently published in journals Cell Death & Disease and Oncogene. The original news article was posted on the University of South Australia website. Images courtesy of CCB.

The Australian Cancer Research Foundation has supported the Centre for Cancer Biology by providing two grants, totalling AUD $5.6 million, towards cutting edge cancer research equipment and technology.