Estimation of microRNA (miRNA) enrichment by mapping the sequencing data to the reference.

The list of reference sequences includes hairpin miRNA transcripts, matrix RNAs (mRNAs), ribosomal RNAs (rRNAs), “filtering” RNAs (transfer RNAs, repetitive genome elements, SOLiD™ adapter sequences). Mapping was performed by Bioscope v.1.3 with a seed length of 19, allowing two mismatches. cDNA libraries were constructed on the basis of short RNA fractions: L1 – RNA fraction from the tumour tissue of mice with LLC treated with saline buffer (RNASTc); L2 – RNA fraction from the tumour tissue of mice with LLC treated with RNase A (RNASTR); L3 – RNA fraction from the blood serum of mice with LLC treated with saline buffer (RNASSc); L4 – RNA fraction from the blood serum of mice with LLC treated with RNase A (RNASSR). *- number of reads (percentage of total number mapped on the group of RNAs).