[Expression and Clinical Significance of Serum MiR-424 and MiR-765 in Multiple Myeloma].

Objective: To investigate the expression and clinical significance of miR-424 and miR-765 in patients with multiple myeloma (MM).

Methods: The eighty-one MM patients admitted to Sanya Central Hospital from January 2017 to July 2020 were divided into phase Ⅰ (n=16), phase Ⅱ (n=25) and phase Ⅲ (n=40) according to the international staging system, while they were divided into IgG type (n=46), IgA type (n=19), light chain type (n=10) and non secretory type (n=6) according to the results of immunotyping. Another 50 healthy normal persons in the same period were selected as the control group. The levels of serum miR-424, miR-765 and Cystatin C (Cys-C) were measured in each group. The diagnostic value of serum miR-424, miR-765 and Cys-C in MM was estimated by ROC curve. Pearson correlation was used to analyze the correlation between serum levels of miR-424, miR-765 and Cys-C in MM patients.

Results: The serum levels of miR-424 (2.74±1.30 vs 0.85±0.26), miR-765 (2.05±0.82 vs 0.63±0.17) and Cys-C ［(2.18±0.86 vs 0.72±0.15) mg/L］ in MM group were significantly higher than those in control group (P<0.001). The serum levels of miR-424 (5.08±2.36 vs 1.12±0.34, 2.24±0.93), miR-765 (3.50±1.52 vs 0.74±0.20, 1.78±0.65) and Cys-C ［(3.81±1.30 vs 0.92±0.24, 1.68±0.55) mg/L］ in MM patients at stage Ⅲ were significantly higher than those in patients at stage Ⅰ and Ⅱ (P<0.001). Also the serum levels of the three molecules in phase II were significantly higher than those in phase I (P<0.001). The serum levels of miR-424 and miR-765 in MM patients at IgG type were significantly higher than those at IgA, light chain and non secretory types (P<0.001). ROC curve analysis showed that the area under the curve (0.952，95%CI: 0.890-0.993) was greatest for the combination of miR-424, miR-765 and Cys-C for diagnosis of MM, and its sensitivity and specificity were 95.0% and 87.2%. The results of correlation analysis showed that the serum levels of miR-424 and miR-765 were positively correlated with Cys-C (r=0.795，r=0.760).

Conclusion: The serum levels of miR-424 and miR-765 in MM patients are significantly increased in the pattern increasing with the progression of MM stage. Combined with Cys-C, miR-424 and miR-765 have high value in the diagnosis of MM.