Homo sapiens C/D box snoRNA U50. This snoRNA was cloned by Kiss-Laszlo et al. (1996), and predicted to guide the 2'O-ribose methylation of both 28S rRNA C2848 and G2863, although the latter was not mapped by Maden (1990). A closely related copy, U50B, with mutations in both anti-sense guiding sequences, resides in the same host gene.
A t(3;6)(q27;q15) translocation found in a patient with B-cell lymphoma fuses the 5' part of the BCL6 gene to the 3' part of the U50/U50B host gene (Tanaka et al., 2000). U50 acts as a tumor-suppressor in prostate cancer cells. A 2-bp homozygous deletion in the U50 sequence is associated with clinically significant prostate cancer (Dong et al., 2008).