X-chromosome inactivation (XCI) is not unique to female cells and may confer some survival advantage to male cancer cells, according to scientists at the Dana-Farber Cancer Institute at Harvard. The noncoding RNA XIST (acronym for X-inactive specific transcript), which in female mammals (of genotype XX) inactivates one of the X chromosomes, preventing the overexpression of the genes of the repeated chromosome from early stages of embryonic development, also acts somatically in some male cancers, compensating for the loss of the entire chromosome.

“We found that a small percentage of male cancers are expressing XIST, which normally is expressed in female cancers. And the percentage of male cancers that express XIST is variable depending on the cancer type,” Srinivas Viswanathan, researcher in the Department of Medical Oncology at the Dana-Farber Cancer Institute at Harvard and assistant professor of Medicine at Harvard Medical School, told BioWorld.