Extra chromosomes —long a mystery in tumors—may help them grow

Cancer cells are sloppy with their DNA, often gaining entire chromosomes as they proliferate. Now, researchers have found that this extra DNA can rev up the cells' growth and stymie one of the body's main anticancer defenses. This chromosomal hoarding may leave some tumors susceptible to certain drugs, however, opening the possibility of tailored treatments. The study, in which researchers used gene editing to compare cells with and without extra chromosomes, "is important, it's novel, and it was carried out in a very elegant way," says cell biologist Uri Ben-David of Tel Aviv University, who wasn't connected to the research. Cancer cells are riddled with genomic alterations. The most common change, known as aneuploidy, involves loss or gain of full chromosomes or the sections of chromosomes termed arms. About 90% of tumors and 75% of blood cancers are aneuploid. Although aneuploidy could foster the development and growth of cancer, it might instead be a result of the turmoil in cancer cells and have no positive or negative effects. Determining whether cancer cells gain from abnormal chromosome numbers has proved difficult. "For a long time, the only thing we could do is observe aneuploidy," says cancer biologist Jason Sheltzer of Yale University School of Medicine. "It was very hard to manipulate." However, researchers have recently begun to deploy the CRISPR/Cas9 genome editor, which allows scientists to snip out DNA at specific locations or insert new seq...
Source: ScienceNOW - Category: Science Source Type: news