ObjectiveTo investigate the expression levels of microRNA(miR)-17-5p and phosphotase and tensin homolog(PTEN) in diffuse large B-cell lymphoma(DLBCL), and their clinical significance.

MethodsThe expression levels of miR-17-5p and PTEN in 82 cases of DLBCL carcinoma tissues and 30 cases of lymph node reactive hyperplasia tissues(control group) were detected using real-time quantitative PCR.The differences of the expression levels of miR-17-5p and PTEN between groups, and their relationship with clinicopathological features were analyzed.According to miR-17-5p sequence, the miR-17-5p inhibitors and inhibitor controls were synthesized, and transfected into the DLBCL cell lines.The MTT cell proliferation assay and Transwell chamber assay were used to observe the effects on the proliferation and invasion ability of tumor cells.The Kaplan-Meier survival analysis was used to analyze the differences between the different expression levels of miR-17-5p and PTEN and prognosis of patients.

ResultsThe relative expression level of miR-17-5p in tumor tissues was higher than that in normal tissues(P < 0.01).The relative expression level of PTEN in tumor tissue was lower than that in normal tissue(P < 0.01).The results of Pearson linear correlation analysis showed that the expression level of miR-17-5p was negatively correlated with the PTEN expression in tumor tissues(r=-0.612, P < 0.01).The expression level of miR-17-5p in patients with primary tumor site locating intra-ganglia, lactic dehydrogenase(LDH) ≤ 245 U/L and clinical stagesⅠ-Ⅱ were higher than that in patients with primary tumor site locating extra ganglia, LDH>245 U/L and clinical stage Ⅲ-Ⅳ, and the expression level of PTEN in patients with primary tumor site locating intra-ganglia, LDH ≤ 245 U/L and clinical stagesⅠ-Ⅱ was lower than that in extra ganglia, LDH>245 and linical stage Ⅲ-Ⅳ(P < 0.05 to P < 0.01).Compared with the transfection inhibitor control, the expression levels of miR-17-5p and PTEN in SU-DHL 8 cells transfected with miR-17-5p inhibitor were lower and higher, respectively(P < 0.01).Compared with the transfection inhibitor control, the proliferation and invasion ability of DLBCL cells transfected with miR-17-5p inhibitor after 96 h was significantly attenuated(P < 0.05).In Transwell chamber assay, the number of transmembrane cells transfected with miR-17-5p inhibitor was significantly reduced compared with the transfection inhibitor control group(P < 0.05).The 3-year overall survival rate of patients with high miR-17-5p was lower than that of patients with low miR-17-5p(P < 0.05), and that of patients with low PTEN expression was lower than that of patients with high PTEN expression(P < 0.05).

ConclusionsThe expression level of miR-17-5p increases, while the expression level of PTEN decreases in patients with DLBCL.Both of them are involved in the occurrence and development of DLBCL, and may become a new tumor marker for DLBCL diagnosis and treatment.