New protein crucial link to cancer

Scientists have discovered a new protein that may play a critical role in the development of cancer.

Associate Professor Kum Kum Khanna from the Queensland Institute of Medical Research (QIMR) says in the absence of this protein, defective cells end up with too many chromosomes, a situation called chromosomal instability.

Known as Cep55, the protein regulates the final stages of mitosis, ensuring the cell splits equally into two new healthy cells.

In this process, the parent cell’s DNA is replicated and a constriction ring develops that progressively tightens to cleave the cell membrane to produce two daughter cells.

Without Cep55 however, the parent cell cannot completely divide, effectively resulting in the two daughter cells becoming conjoined.

This means the cell now has two nuclei – twice the normal amount of DNA – and will continue to replicate itself over time, eventually leading to cancer.

QIMR scientists are now investigating the possible link between Cep55 and cancer development.

“Scientists now know that a complex interwoven network controls cell growth and that cancer results when there are changes within the key genes that control the cell division machinery,” Professor Khanna said.

“Proper functioning of this machinery ensures that each daughter cell receives the correct number of chromosomes when the parent cell divides.

“Irregular numbers of chromosomes are hall marks of many cancers.”