Purpose
Despite recent advances in colorectal cancer (CRC) treatment, the prognosis of CRC patients still remains substandard, and metastatic recurrence following curative surgery is the leading cause of poor prognosis. Therefore, it is imperative to identify prognostic markers to predict the clinical outcome of CRC. Recent evidence revealed the new role of small nucleolar RNAs (snoRNAs) in oncogenesis. Herein, we systematically evaluated dysregulation of snoRNAs in CRC, and clarified the biomarker potential and biological significance of snoRNAs in CRC.
Experimental Design
We analyzed expression levels of four snoRNAs in 274 colorectal tissues from three independent cohorts, and 6 CRC cell lines. The functional characterization for the role of SNORA42 in CRC was investigated through a series of in vitro and in vivo experiments.
Results
In the screening phase, expression levels of all four snoRNAs were significantly elevated in CRC tissues than in corresponding normal mucosa. In the clinical validation cohort, increased SNORA42 expression was an independent prognostic factor for overall survival and disease free survival, and was an independent risk factor for distant metastasis. SNORA42 expression negatively correlated with overall survival in an additional independent cohort, and identified the patients with high risk for recurrence and poor prognosis in stage II CRC. Furthermore, in vitro and in vivo analysis showed that SNORA42 overexpression resulted in enhanced cell proliferation, migration, invasion, anoikis resistance, and tumorigenicity.
Conclusion
SNORA42 appears to a novel oncogene and could serve as a promising predictive biomarker for recurrence and prognosis in CRC patients.