When cell division goes wrong

It takes precise timing of the launch sequence to put a rocket into space. The same is true for cell division, according to scientists at OMRF. Errors in timing could make some cancer cells more malignant.

“When cells divide, everything has to happen at the right time and in the right order, or you’ll have a catastrophe,” said OMRF researcher Gary Gorbsky, Ph.D. “In my lab, we’re trying to understand how a cell knows the right sequence and what can happen when that goes wrong.”

Gorbsky, who holds the W.H. and Betty Phelps Chair in Developmental Biology at OMRF, and foundation scientist Sushama Sivakumar, Ph.D., found a complex of proteins plays a big role in moving cell division forward.

“Cells don’t just divide recklessly,” said Gorbsky, who is chair of OMRF’s Cell Cycle and Cancer Biology Research Program. “They must pass a series of checkpoints, kind of like quality control, making sure everything is in the right place.”

After DNA in the cell’s nucleus is duplicated, the chromosomes are lined up and pulled apart, one copy to each cell. But when scientists suppressed the Ska3 complex in dividing cells in culture, the chromosomes being pulled would not release.

“Ska3 helps ignite the next stage, so without it, the chromosomes were kept in a state of tension until it became too much and they were ripped apart,” Gorbsky said. “If cells divide with damaged chromosomes, they might just die, or there could be more serious consequences.”

Cancer cells that are initially in a benign state can gain or lose chromosomes or parts of chromosomes and then become malignant and dangerous, he said. Defects in cell division can drive cancers to become more deadly.

Other OMRF scientists who contributed to the research are Susannah Rankin, Ph.D., Aaron Tipton, Ph.D., and John Daum.

The research was funded by grant No. GM50412 from the National Institute of General Medical Sciences and by the McCasland Foundation.