Scheme of the experiment for cDNA library preparation.

Mice with intramuscularly (i.m.) implanted LLC were treated with saline or RNase A at a dose of 0.7 µg/kg for 10 days starting on the 4^th day after tumour transplantation. At 1 h after the last injection, tumour tissue and blood serum samples were collected and pooled according to groups, and long and short RNA fractions were isolated. Long RNA fractions RNA_LTc and RNA_LTR were used for qPCR for the evaluation of the expression levels of miRNA processing genes. Short tumour-derived (RNA_STc and RNA_STR) and serum-derived (RNA_SSc and RNA_SSR) RNA fractions were used for the preparation of cDNA libraries and subsequent sequencing on the SOLiD™ ABA 3.5 platform and for stem-loop qPCR.