YsRNA aberrant expression in colorectal cancer patients.

Abstract

e13525 Background: Cancer is a disease characterized by uncontrolled cell proliferation. DNA replication is the main driving force behind cell proliferation in both normal development and cancer. Non-coding Y-RNAs are important factors in initiating DNA replication in the nuclei of human cells. Excessive expression of Y-RNA is characteristic of tumors of the bladder, cervix, kidney, lung and prostate. It has also been shown that the level of small RNAs formed from the 3'- and 5'-ends of Y-RNA is significantly higher in patients with certain types of cancer compared to healthy people, therefore, these RNAs may have diagnostic value. However, for colon tumors, data on the expression of Y-RNA/YsRNA obtained in previous studies are ambiguous. The aim of the study was to analyze the differential expression of YsRNA in the tumor and non-tumor tissue of patients with CRC using next generation sequencing (NGS). Methods: For NGS, 10 patients with CRC (colon adenocarcinoma, G2). were selected. Small RNA fractions were isolated using the mirVana miRNA Isolation Kit protocol (Ambion, Life Science Technologies, USA). The library was prepared for sequencing using the TruSeq Small RNASample Preparation Kit (Illumina, USA). Sequencing of the nucleotide sequences of cDNA libraries was performed using a MiSeq (Illumina, USA). The determination of the copy number of Y-RNA fragments (YsRNA, 19-34 bp) was carried out by comparing the nucleotide sequence of the sequenced molecules in each sample with the known nucleotide sequences presented in the databases. In the analysis of differential expression, the edgeR method, implemented in the R language, was used. Results: Several different fractions of YsRNA were detected in tumor and non-tumor tissues: hY3sRNA (the most represented fraction, more than 70%), hY5sRNA and hY1sRNA. In tumor tissue relatively non-tumor, a statistically significant (p < 0.001) increase of 4 and 6 times the number of copies of hY3sRNA and hY5sRNA, respectively, was detected. The function of YsRNA in tumor and normal cells has not yet been established. Conclusions: Thus, in the tumor colon tissue differential expression of 2 YsRNA fractions - hY3sRNA and hY5sRNA, was detected. These YsRNAs can become promising tumor markers and targets for the treatment of CRC, as well as make certain contributions to understanding the mechanisms of carcinogenesis in this nosology.