The microRNA (miRNA) pathway has emerged as one of the biologic pathways implicated in stem cell regulation. miRNA is a noncoding, single-stranded RNA consisting of 20-25 nucleotides that inhibits the protein production at the step of translation. The molecular effects of lidocaine and procaine on adipose stem cells were investigated by examining RNA expression array.

Adipose stem cells were isolated from a prior abdominal liposuction procedure. The human adipose stem cells were cultured and then added to a mixture of 1 ml of culture medium plus 1 ml of 2% lidocaine or 2% procaine for the duration of 30 minutes. The expression levels of miRNAs were estimated by using peptide nucleic acid (PNA)-miRNA array analysis throughout the denaturation and hybridization processes after the isolation of miRNA. The miRNAs detected by microarray that either decreased by half fold or increased by 1.5 fold from the control level were interpreted as significant.

According to microarray analysis there were 61 miRNAs in total, and no miRNA had decreased expression levels. The stem cells treatment with lidocaine showed 4 alteration of expression with miR-9a^* (1.53 fold), miR-29a (1.64 fold), miR-296-5p (1.64 fold) and miR-373 (1.94 fold). The stem cells treated with procaine showed 32 miRNAs that were significantly up-regulated with a range of 1.5 to 2.06 fold. They were stem cell differentiation-related miRNAs, apoptosis and cell cycle-associated miRNAs, immunity-associated miRNAs and hormonal response-related miRNAs.

Lidocaine and procaine affect the miRNA expression on adipose stem cells and the effect of procaine is more marked than that of lidocaine.