City scientists spot cancer cell split

Research will help discover sites which can be targeted by drugs

The mixed lineage leukemia protein, which is closely associated with leukemia or blood cancer, plays a crucial role in cell division according to research carried out at Centre for DNA Fingerprinting and Diagnostics, Hyderabad.

MLL is a very aggressive blood cancer and is found to occur more in children. MLL fusion proteins are the result of chromosomal translocations affecting the MLL gene.

Dr Shweta Tyagi explained, “Chromosomal translocations in the MLL gene occur frequently in acute and lymphoid leukemia. Such translocations give rise to new fusion proteins. While most researchers concentrate on the fusion proteins as the cause of cancer our team has looked into how it regulates the cell cycle.”

The research has been published in the Developmental Cell.

The study found that while undergoing cell division, all chromosomes align themselves in a straight line so that they can be divided equally into two daughter cells.

Dr Tygai explained, “To segregate, the chromosomes attach to the spindle microtubules and act like ropes pulling the chromosomes to each end. During our research we found that when MLL is knocked down the chromosomes keep trying to align but are not successful. This process takes less than 40 minutes in a normal cell but goes on for several hours in the absence of MLL. As a result, both daughter cells do not receive equal number of chromosomes and such cells are highly likely to become cancerous.”

The findings have shown the researchers what happens during cell division and what leads to cancer.

This research is expected to help find drug targets for leukemia. Researchers have to carry out further studies to understanding different drug targets which can be effective.