Researchers from the Bellvitge Biomedical Research Institute (IDIBELL) in Barcelona, Spain, have studied the role of a peculiar class of small non-coding RNAs that are mainly expressed in the human male germline. Whereas messenger RNAs transmit the genetic information required for protein synthesis, non-coding RNAs are functional molecules that are never translated into proteins and have important roles in diverse cellular processes. In human spermatozoa, these tiny RNAs are epigenetically regulated (by changes in the genome that do not alter the DNA sequence, such as DNA methylation) and play a critical role in male germline development. Importantly, these RNAs have also been detected in human cancer cells.
In a work published in the January 2014 issue of Epigenetics, which is entirely devoted to "Non-coding RNAs in Epigenetic Regulation," the researchers asked if in their natural functional context (the normal human testis) these small RNAs undergo aberrant epigenetic regulation, compromising their function and contributing to the transformation of cells into testicular tumor cells. The reported data suggest that epigenetic disruption of an entire small non-coding RNA pathway in human testis is indeed a hallmark for the development of testicular tumors.