ABSTRACT
Objective To explore the effect of imiquimod (IMQ) on the proliferation of glioma U87 cell line U87. Methods U87 cells were divided into control group, 1 mmol/L I mmol/L MQ group, 5 mmol/L IMQ group, 1 mmol/L IMQ+ STAT3 inhibitor(STAT3-IN) group and 5 mmol/L IMQ + STAT3-IN group. To detect the number of 5-ethynyl-2 ' - deoxyuridine(EdU) -labeled cells or proliferation absorbance(A) values in each group by EdU and MTT assays. Interleukin (I L) - 6 mRNA, tumor necrosis factor (TNF) -a mRNA and protein content in U87 cells of each group were detected by Real-time PCR or ELISA. Western blotting was used to detect the protein expression of STAT3, phosphorylated STAT3 (p - S T A T 3), nuclear factor (N F) -KB and phosphorylated NF-KB (p-NF-KB) in U87 cells of each group. Results Compared with the control group, the number of EdU-labeled cells and absorbance values of U87 cells were successively decreased in 1 mmol/L IMQ group and 5 mmol/L IMQ group, showing a dose-dependent manner (P < 0 . 0 1, n— 1 0) . However, the number of EdU-labeled cells and the A values in IMQ + STAT3-IN group and 5 mmol/L IMQ + STAT3-IN group were significantly reduced. Compared with the control group, the protein expression of STAT3, p-STAT3, N F - K B, P ~ N F - K B, IL-6 and TNF-a were continuing low level in U87 cells of 1 mmol/L IMQ group and 5 mmol/L IMQ group (P < 0 . 0 1, * = 1 0) . As well as in 1 mmol/L IMQ + STAT3-INgroup and 5 mmol/L IMQ + STAT3-IN group, the proteins of above were low expressed (P < 0 . 01, n— 10) . Conclusion Imiquimod decreased the contents of IL-6 and TNF-a by down-regulating S T A T 3 / N F - K B pathway, and thus inhibited the proliferation of U87 cells.