OBJECTIVETo explore the expression and significance of miRNAs and Th17 related cytokines in patients with multiple myeloma (MM).

METHODSA total of 27 MM patients and 8 health controls were enrolled in this study. The expression of miR-15a/16,miR-34a,miR-194-2-192 cluster and miR-181a/b in bone marrow were detected by real-time quantitative PCR (qRT-PCR). Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of Th17 related cytokines interleukin-17 (IL-17), IL-21, IL-22, IL-23 and IL-27 in peripheral blood plasma. The role of miRNAs and Th17 related cytokines was analyzed in the development of MM.

RESULTSThe expression of miR-15a/16,miR-34a,miR-194-2-192 cluster in MM patients were significantly lower than those of the health controls, while miR-181a/b were exactly the reverse (P<0.05). The levels of IL-17, IL-21 and IL-27 were up-regulated in MM patients compared to health controls while IL-22 was down-regulated (P<0.05). There was no significant difference of IL-23 between the two groups. The levels of miRNAs and Th17 related cytokines had associated with ISS but not with some clinical parameters (such as gender, age, disease classification). Higher expression of IL-17, IL-21, IL-23, IL-27, miR-181a/b and lower expression of miR-15a/16,miR-34a,miR-194 and IL-22 were observed in the end stage than the early stage of MM patients (P<0.05). There was a significant correlation between miRNAs and Th17 related cytokines.

CONCLUSIONUp-regulated IL-17, IL-21 and IL-27 may potentially down-regulate the expression of several miRNAs in MM patients. Establishment of the relationship may be useful for understanding the pathogenesis of MM and for clinical diagnosis of the disease.