Expression of miR-17-5p in the plasma of patients with multiple myeloma and its role in tumorigenesis and development

Abstract

Objective: To investigate the expression of miR-17-5p in the plasma of patients with multiple myeloma (MM) and its role in tumorigenesis and development. Methods: Patients diagnosed with unidentified monoclonal gammopathy of undetermined significance (MGUS) or MM in Cancer Hospital of Zhengzhou University from April 2013 to April 2018 were enrolled, as well as 20 healthy volunteers. Reverse transcription polymerase chain reaction (qRT-PCR) was used to detect the expression levels of miR-17-5p in plasma circulation and bone marrow mononuclear cells. There were 22 cases with newly diagnosed MM (NDMM), 11 cases with complete remission MM (CRMM) and 59 case with recurrent refractory MM (RRMM). The expression levels of miR-17-5p in each group were analyzed. The correlation analysis was used to evaluate the relationship between plasma miR-17-5p and the proportion of serum M protein and bone marrow plasma cells in patients with untreated multiple myeloma. Receiver operating characteristic (ROC) curve was used to evaluate the possibility of plasma miR-17-5p as a molecular marker related to MM diagnosis. After over expression or knockdown of miR-17-5p expression, CCK-8 method was used to detect the effect of miR-17-5p on the proliferation of MM cell line. The effect of miR-17-5p on the proliferation of MM cells was detected in nude mice subcutaneous tumorigenesis experiment. Results: The expression of miR-17-5p in bone marrow mononuclear cells in NDMM and RRMM group were higher than those in healthy volunteers [1.37 (0.47, 4.87), 2.68 (1.02, 5.02) vs 1.00 (1.00, 1.00), all P<0.05], and the expression levels of miR-17-5p in plasma were also higher than those in healthy control group [1.85 (0.92, 3.51), 2.79 (1.22, 5.04) vs 1.00 (1.00, 1.00), all P<0.05]. The expression of miR-17-5p in MM cell lines such as KMS-11, RPMI-8226, H929, MM-1R, U266B1 were higher than that in bone marrow mononuclear cells of healthy control group (3.96±0.68, 1.58±0.32, 3.51±0.55, 5.08±0.76, 3.22±0.75 vs 1.00±0, all P<0.05) ; Plasma miR-17-5p was positively correlated with the ratio of serum M protein and bone marrow plasma cells (r=0.50, P<0.05; r=0.60, P<0.01). ROC curve showed that the specificity was 0.591 and the sensitivity was 0.900 of plasma miR-17-5p as a molecular marker related to diagnosis (area under ROC curve=0.74, cut-off value: 0.491). CCK-8 results showed that over expression of miR-17-5p increased the proliferation of RPMI-8226 and NCI-H929 cell lines at 72 hours compared with the control group (1.37±0.11 vs 1.07±0.09, 2.14±0.09 vs 1.82±0.11, both P<0.05), and low expression of miR-17-5p reduced the proliferation of NCI-H929 and MM-1R cell lines at 72 hours compared with the control group (1.38±0.09 vs 1.83±0.11, 1.45±0.10 vs 1.73±0.09, both P<0.05). The subcutaneous tumorigenesis experiment in nude mice showed that the tumor volume of miR-17-5p over expression group was larger than that of the control group [(1 865±181) vs (1 389±227) mm3, P<0.05], and the tumor volume of miR-17-5p low expression group was smaller than that of the control group [ (1 006±171) vs (1 389±227) mm3, P<0.05]. Conclusion: miR-17-5p may play an oncogene role in MM cell lines as a plasma molecular marker related to the development of MM disease.