去泛素化酶USP33通过下调SLIT2/ROBO1信号通路抑制肺腺癌的侵袭和转移

USP33 suppresses lung adenocarcinoma lung cell invasion and metastasis by down-regulating SLIT2/ROBO1 signaling pathway

目的探讨去泛素化酶USP33参与调节SLIT2/ROBO1信号通路抑制肺腺癌的侵袭转移的机制。方法采用q PCR、免疫组化的方法检查USP33在肺腺癌中的表达,利用A549、SPC-A-1细胞,以沉默USP33后作为沉默组,空白组作为对照,72 h后用q PCR与Western blot检测USP33的沉默效果,利用划痕实验、细胞迁移和侵袭基质胶法检测USP33沉默后对细胞侵袭转移的影响,利用Western blot检测USP33的沉默后SLIT2和ROBO1表达,IL6刺激后USP33的表达。结果 q PCR、免疫组化显示与肺腺癌癌组织相比,癌旁组织USP33表达量明显增加(P<0.05);与空白组相比,qPCR、Western blot结果显示沉默组USP33的表达量明显下降(P<0.05);划痕实验,Transwell迁移实验,Boyden侵袭实验提示USP33沉默后细胞迁移、侵袭转移率明显增加(P<0.05);抑制USP33后,SLIT2和ROBO1表达均下调;IL6刺激使USP33的表达增加(P<0.05)。结论 USP33抑制A549、SPC-A-1细胞迁移、侵袭转移,其侵袭转移的机制可能与炎症因子IL6、SLIT2/ROBO1信号通路存在交叉作用。

Objective To investigate the role of USP33 as an independent prognostic marker in the regulation of SLIT2/ROBO1 signaling pathway to inhibit lung adenocarcinoma invasion and metastasis. Methods The expression of USP33 in 20 lung adenocarcinoma specimens was detected by q PCR and immunohistochemistry. A549 and SPC-A-1 cells with small interfering RNA（si RNA）-mediated USP33 silencing were examined for changes in invasion and metastasis abilities using scratch assay and Matrigel assay. Western blotting was used to detect the expression of SLIT2 and ROBO1 in the cells after USP33 silencing and the expression of USP33 after interleukin-6（IL-6） stimulation. Results q PCR and immunohistochemistry showed that USP33 was significantly decreased in lung adenocarcinoma tissues as compared with the adjacent tissues. USP33 silencing in A549 and SPC-A-1 cells significantly promoted the cell migration, invasion and metastasis and obviously down-regulated the expressions of SLIT2 and ROBO1. IL-6 stimulation of the cells obviously enhanced the expression of USP33. Conclusion USP33 silencing can promote the migration, invasion and metastasis of lung adenocarcinoma cells in vitro, and the mechanism may involve IL-6 and SLIT2/ROBO1 signaling pathways.