Flavanones structure-related inhibition on TPA-induced tumor promotion through suppression of extracellular signal-regulated protein kinases:: Involvement of prostaglandin E2 in anti-promotive process
Flavanones structure-related inhibition on TPA-induced tumor promotion through suppression of extracellular signal-regulated protein kinases:: Involvement of prostaglandin E2 in anti-promotive process
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DOI：
10.1002/jcp.10154
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发表时间：
2002-10-01
影响因子：
5.6
通讯作者：
Chen, YC
中科院分区：
文献类型：
--
作者：
Ko, CH;Shen, SC;Chen, YC
黄烷酮的生物学功能已被广泛研究，但其对12-O-十四酰佛波醇13-乙酸酯（TPA）诱导的促癌作用的结构相关活性尚不清楚。在本研究中，黄烷酮、2 ′-OH黄烷酮、4 ′-OH黄烷酮、6-OH黄烷酮在八种测试的黄烷酮中对TPA诱导的NIH 3 T3细胞增殖效应显示出最显著的剂量依赖性抑制。TPA诱导有丝分裂原活化蛋白激酶（MAPK）磷酸化、鸟苷酸脱羧酶（ODC）、c-Jun和环氧合酶2（考克斯-2）蛋白表达呈时间依赖性，最大诱导时间点为MAPK磷酸化1h，其他时间为6 h。黄烷酮、2 '-OH黄烷酮、4'-OH黄烷酮、6-OH黄烷酮对TPA刺激的MAPK磷酸化、考克斯-2、ODC、c-Jun蛋白表达具有剂量依赖性抑制作用。TPA可诱导NIH 3 T3细胞产生前列腺素E-2（PGE（2）），黄烷酮、2 ′-羟基黄烷酮、4 ′-羟基黄烷酮、6-羟基黄烷酮可显著抑制TPA诱导的PGE（2）产生。加入PGE_2可逆转黄烷酮、2 ′-羟基黄烷酮、4 ′-羟基黄烷酮、6-羟基黄烷酮对TPA诱导的细胞增殖的抑制作用。ERK的特异性抑制剂PD 98059可抑制TPA诱导的MAPK磷酸化，同时降低考克斯-2、c-Jun和ODC蛋白表达，并呈剂量依赖性抑制TPA诱导的细胞增殖。这些结果表明，PGE 2是TPA诱导细胞增殖的重要介质，MAPK磷酸化位于TPA诱导细胞增殖反应中考克斯-2、c-jun和ODC基因表达的上游。此外，黄烷酮、2 ′-OH黄烷酮、4 ′-OH黄烷酮、6-OH黄烷酮（100 μ M）抑制TPA诱导的集落形成，这与阻断MAPK磷酸化、ODC、c-Jun和考克斯-2蛋白表达有关。1，1-二苯基-2-苦基肼基（DPPH）法测定结果表明，8个化合物中的黄烷酮、2 ′-羟基黄烷酮、4 ′-羟基黄烷酮、6-羟基黄烷酮均没有明显的抗自由基活性。总之，本研究提供的分子证据表明，黄烷酮，2 '-OH黄烷酮，4'-OH黄烷酮，6-OH黄烷酮是有效的抑制剂TPA诱导的反应，没有明显的细胞毒性，通过抑制PGE 2的产生;黄烷酮的抗自由基活性与防止肿瘤促进的发生无关。我们认为，阻断TPA诱导的细胞内信号转导可能参与了黄烷酮的抗促癌机制。(C)2002 Wiley-Liss，Inc.
Biological functions of flavanones have been studied extensively, however, the structure-related activities of flavanones on 12-o-tetradecanoylphorbol 13-acetate (TPA)-induced promotive effects are still unclear. in this study, flavanone, 2'-OH flavanone, 4'-OH flavanone, 6-OH flavanone showed the most significant dose-dependent inhibition on TPA-induced proliferative effects among eight tested flavanones in NIH3T3 cells. TPA-induced mitogen activated protein kinases (MAPK) phosphorylation, ornithine decarboxylase (ODC), c-Jun, and cyclooxygenase 2 (COX-2) protein expressions in a time-dependent manner, and the maximal inductive time point is at I h for MAPK phosphorylation and 6 h for others. Flavanone, 2'-OH flavanone, 4'-OH flavanone, 6-OH flavanone showed the dose-dependent inhibition on TPA-stimulated MAPK phosphorylation, COX-2, ODC, c-Jun protein expressions. Induction of, prostaglandin E-2 (PGE(2)) production was detected in TPA-treated NIH3T3 cells, and flavanone, 2'-OH flavanone, 4'-OH flavanone, 6-OH flavanone inhibited significantly PGE2 production induced by TPA. Addition of PGE2 reverses the inhibitory activities of flavanone, 2'-OH flavanone, 4'-OH flavanone, 6-OH flavanone on TPA-induced proliferation. And, PD98059, a specific inhibitor of ERKs, inhibited TPA-induced MAPK phosphorylation, accompanied by decreasing COX-2, c-Jun, and ODC protein expression, and showed dose-dependent inhibition on TPA-induced proliferation in cells. These results demonstrated that PGE2 is an important mediator in TPA-induced proliferation, and MAPK phosphorylation was located at the upstream of COX-2, c-jun, and ODC gene expressions in TPA-induced responses. Furthermore, flavanone, 2'-OH flavanone, 4'-OH flavanone, 6-OH flavanone (100 muM) suppressed TPA-induced colony formation associated with blocking MAPK phosphorylation, ODC, c-Jun, and COX-2 proteins expression. And, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay showed that flavanone, 2'-OH flavanone, 4'-OH flavanone, 6-OH flavanone did not perform potent anti-radical activities among these eight tested compounds. In conclusion, this study provided molecular evidences to demonstrate that flavanone, 2'-OH flavanone, 4'-OH flavanone, 6-OH flavanone were potent inhibitors on TPA-induced responses without notable cytotoxicity through suppression of PGE2 production; and anti-radical activity of flavanones was not correlated with preventing the occurrence of tumor promotion. We proposed that,blocking TPA-induced intracellular signaling responses might be involved in the anti-promotive mechanism of flavanones. (C) 2002 Wiley-Liss, Inc.