ERK1/2 及p38通路调节P2Y受体介导的前列腺癌细胞体外侵袭

目的 探讨细胞外信号调节激酶(ERK1／2)及p38激酶在P2Y嘌呤受体活化介导的前列腺癌细胞体外侵袭中的作用。方法 以脂质体法将负显性MAPK激酶1(KA-MEKl)及野生型p38磷酸酶(MKP-5)转染人前列腺癌细胞PC-3亚系1E8(高转移)和284(不转移)细胞,以Western印迹法检测细胞经P2Y嘌呤受体激动剂ATP刺激后ERK1／2及p38活化情况,并用体外侵袭实验检测在P2Y受体介导的前列腺癌细胞体外侵袭效应中ERK1／2及p38通路所起的作用。结果ATP可以激活ERK1／2及p38通路并促进前列腺癌细胞体外侵袭,这种侵袭促进效应可以分别被MEK1抑制剂PD98059及p38抑制剂SB203580所抑制。转染KA-MEK1及MKP-5使侵袭细胞数分别降低约40％及60％。如果加入抑制剂同时抑制ERKl／2及p38通路,细胞的侵袭能力被抑制约76％。结论 ERK1／2及p38通路在P2Y嘌呤受体活化所介导的前列腺癌细胞侵袭中起重要作用。

ERK1/2 and p38 kinases are important regulators in P2Y receptor-mediated prostate cancer invasion

Objective To explore whether ERK1/2 and p38 pathways mediate P2Y receptor-induced prostate cancer invasion.Methods The two subclones from the PC-3 human prostate carcinoma cell line: 1E8 (highly metastatic) and 2B4 (non-metastatic), were cultured and transfected with the plasmid pcDNA3-KA-MEK1 containing the dominant negative mutant of MEK1(KA-MEK1)and wild type MKP-5 (a dual-specificity phosphatase of p38). P2Y receptor-activated ERK1/2 and p38 kinases were detected using phospho-specific antibodies directed against the dually phosphorylated active forms of these kinases by Western blotting. P2Y receptor agonists ATP and P2Y receptor antagonist suramin were used respectively to observe their effects on the activity of ERK1/2. The roles ERK1/2 and p38 pathways play in P2Y receptor-induced in vitro invasion were detected by in vitro invasion assay. The cells were pre-treated with ATP, SB203580, a p38 inhibitor, and PD98059, a blocker of ERK1/2 pathway, respectively.Results ATP activated ERK1/2 and p38 kinase time-dependently. Suramin significantly inhibited the activation of ERK1/2 and p38 kinase by ATP. ATP stimulated prostate cancer cell invasion. The stimulated cancer cell invasion was significantly inhibited by pretreatment of the cells with PD98059 or SB203580. Transfected of 1E8 cells with KA-MEK1 or up-regulation of MKP-5 both, while inhibiting phosphorylation of ERK1/2 or p38, significantly reduced the invasion of prostate cancer cells in vitro. Conclusion P2Y receptor-induced prostate cancer cell invasion is mainly regulated through ERK1/2 and p38 pathways.