Regulatory Role of Small Nucleolar RNAs in Human Diseases

Stepanov, Grigory A.; Filippova, Julia A.; Komissarov, Andrey B.; Kuligina, Elena V.; Richter, Vladimir A.; Semenov, Dmitry V.

Martens-Uzunova et al. demonstrated that some box C/D and box H/ACA snoRNAs, as well as several tRNAs, are overexpressed in prostate cancer cells during the premetastatic stages [54] . The data claim that snoRNAs are capable of active participation in tumor progression. Ribosomal RNA biogenesis is known to be more robust in cancer cells than in normal cells [55] . Therefore, it can be assumed that the increase in snoRNAs level is necessary for the acceleration of rRNA maturation, ribosome assembling, and protein synthesis during tumorigenesis. It should be noted that the relationship between the deregulation of snoRNA expression and rRNA biogenesis in diseases still remains elusive. Further studies in snoRNA research area should be addressed to this issue. [56] . Six snoRNAs-SNORD33, SNORD66, SNORD73B, SNORD76, SNORD78 and SNORA42-were established to be overexpressed both in adenocarcinoma (AC) and SCC [56] . All 6 snoRNAs are present in a stable form in human blood plasma, and their level can be accurately measured by RT-qPCR. A new diagnostic system with 81.1% sensitivity and 95.8% specificity was proposed based on simultaneous assessment of three snoRNAs (SNORD33, SNORD66, and SNORD76) blood plasma levels. According to the data presented, the usage of the three diagnostic genes allows us not only to detect NSCLC, but also to distinguish it from chronic obstructive pulmonary disease. However, the levels of SNORD33, SNORD66, and SNORD76 do not reflect the stage of malignancy or histological origin [56] .