前列腺六段跨膜上皮抗原4对炎症环境下前列腺癌细胞增殖的影响

Effect of six-segment transmembrane epithelial antigen of prostate 4 on proliferation of prostate cancer cells in inflammatory environment

目的探讨脂多糖(LPS)诱导的炎症微环境下前列腺六段跨膜上皮抗原4(STEAP4)在前列腺癌发展中的作用。方法采用LPS诱导前列腺癌细胞PC3和VCa P的炎症环境;将PC3和VCa P细胞分为对照组、LPS处理组(将PC3和VCa P细胞暴露于1μg/ml的LPS)、转染对照组(LPS+转染si-con)和转染沉默组(LPS+转染si-STEAP4)。转染24 h后采用蛋白免疫印迹检测STEAP4水平。采用酶联免疫吸附试验检测细胞因子白细胞介素(IL)-6、IL-8和肿瘤坏死因子-α(TNF-α)的表达水平。采用CCK-8和Ed U染色检测细胞增殖能力。采用蛋白免疫印迹检测环鸟苷酸(c GMP)-c GMP依赖性蛋白激酶(PKG)信号通路相关蛋白表达水平。结果LPS处理组PC3和VCa P细胞的STEAP4蛋白表达水平显著高于对照组(P<0.05);LPS处理组PC3和VCa P细胞的STEAP4蛋白表达水平与转染对照组比较,差异无统计学意义(P>0.05);转染沉默组PC3和VCa P细胞的STEAP4蛋白表达水平显著低于转染对照组(P<0.05)。LPS处理组PC3和VCa P细胞的IL-6、IL-8和TNF-α的表达水平显著高于对照组(P<0.05);LPS处理组和转染对照组PC3和VCa P细胞的IL-6、IL-8和TNF-α的表达水平比较,差异无统计学意义(P>0.05);转染沉默组PC3和VCa P细胞的IL-6、IL-8和TNF-α的表达水平显著低于转染对照组(P<0.05)。LPS处理组PC3和VCa P细胞24、48、72 h的增殖活力均显著高于对照组(P<0.05);LPS处理组和转染对照组PC3和VCa P细胞24、48、72 h的增殖活力比较,差异无统计学意义(P>0.05);转染沉默组PC3和VCa P细胞24、48、72 h的增殖活力均低于转染对照组(P<0.05)。LPS处理组PC3和VCa P细胞的增殖活力显著高于对照组(P<0.05);LPS处理组和转染对照组PC3和VCa P细胞的增殖活力比较,差异无统计学意义(P>0.05);转染沉默组PC3和VCa P细胞的增殖活力显著低于转染对照组(P<0.05)。LPS处理组PC3和VCa P细胞中c GMP、PKG1、PKG2和磷酸化血管扩张剂刺激磷酸蛋白(pVASP)/VASP的相对表达量显著低于对照组(P<0.05);转染对照组和LPS处理组PC3和VCa P细胞中c GMP、PKG1、PKG2和pVASP/VASP的相对表达量比较,差异无统计学意义(P>0.05);转染沉默组的PC3和VCa P细胞中c GMP、PKG1、PKG2和pVASP/VASP的相对表达量显著高于转染对照组(P<0.05)。结论STEAP4沉默能够抑制LPS诱导的前列腺癌细胞的增殖和炎症反应。STEAP4下调可能通过减少细胞增殖和炎症反应来抑制LPS诱导的肿瘤发生。

Objective To investigate the role of six-segment transmembrane epithelial antigen of prostate 4(STEAP4)in the development of prostate cancer in the inflammatory microenvironment induced by lipopolysaccharide(LPS).Methods The inflammatory environment of prostate cancer cells PC3 and VCaP was induced by LPS.PC3 and VCaP cells were divided into control group,LPS treated group(PC3 and VCaP cells were exposed to 1μg/ml LPS),transfection control group(LPS+transfection si-con)and transfection silence group(LPS+transfection si-STEAP4).The STEAP4 level was detected 24 h after transfection by Western blot.The expression levels of cytokines interleukin(IL)-6,IL-8 and tumor necrosis factor-α(TNF-α)were detected by enzyme-linked immunosorbent assay.Cell proliferation was detected by CCK-8 and EdU staining.The expression level of cyclic guanosine monophosphate(cGMP)-cGMP-dependent protein kinase(PKG)signaling pathway related proteins was detected by Western blot.Results STEAP4 protein expression level of PC3 and VCaP cells in LPS treated group was significantly higher than that in control group(P<0.05).There was no significant difference in the expression level of STEAP4 protein in PC3 and VCaP cells in LPS treated group compared with transfection control group(P>0.05).The expression level of STEAP4 protein in PC3 and VCaP cells in transfection silence group was significantly lower than that in transfection control group(P<0.05).The expression levels of IL-6,IL-8,and TNF-αin PC3 and VCaP cells in LPS treated group were significantly higher than those in control group(P<0.05).There were no significant differences in the expression levels of IL-6,IL-8,and TNF-αin PC3 and VCaP cells between LPS treated group and transfection control group(P>0.05).The expression levels of IL-6,IL-8,and TNF-αin PC3 and VCaP cells in transfection silence group were significantly lower than those in transfection control group(P<0.05).The proliferation activity of PC3 and VCaP cells in LPS treated group was significantly higher than that in control group at 24,48,and 72 h(P<0.05).There was no significant difference in the proliferation activity of PC3 and VCaP cells at 24,48,and 72 h between LPS treated group and transfection control group(P>0.05).The proliferation activity of PC3 and VCaP cells in transfection silence group was lower than that in transfection control group at 24,48,and 72 h(P<0.05).The proliferation activity of PC3 and VCaP cells in LPS treated group was significantly higher than that in control group(P<0.05).There was no significant difference in the proliferation activity of PC3 and VCaP cells between LPS treated group and transfection control group(P>0.05).The proliferation activity of PC3 and VCaP cells in transfection silence group was significantly lower than that in transfection control group(P<0.05).The relative expression levels of cGMP,PKG1,PKG2,and phosphorylated vasodilator stimulated phosphoprotein(pVASP)/VASP in PC3 and VCaP cells of LPS treated group were significantly lower than those of control group(P<0.05).There were no significant differences in the relative expression levels of cGMP,PKG1,PKG2,and pVASP/VASP in PC3 and VCaP cells between transfection control group and LPS treated group(P>0.05).The relative expression levels of cGMP,PKG1,PKG2,and pVASP/VASP in PC3 and VCaP cells of transfection silence group were significantly higher than those of transfection control group(P<0.05).Conclusion STEAP4 silencing inhibits the proliferation and inflammatory response of prostate cancer cells induced by LPS.Downregulation of STEAP4 may inhibit LPS-induced tumorigenesis by reducing cell proliferation and inflammatory response.