Department of Pharmacology, School of Pharmacy, Qingdao University, Qingdao, 266021, China.
Department of Pharmacology, School of Pharmacy, Qingdao University, Qingdao, 266021, China.
Biomed Pharmacother. 2018 Jul;103:272-283. doi: 10.1016/j.biopha.2018.04.014. Epub 2018 Apr 24.
Hispidulin, a phenolic flavonoid, exerts potent cytotoxicity towards a variety of human cancers. However, the effects of hispidulin on hepatocellular carcinoma (HCC) and underlying molecular mechanisms of its action remain elusive. The present study investigated the effect of hispidulin on HCC in experimental models, including tumor cell lines and mouse tumor xenograft. Results demonstrated that hispidulin was cytotoxic and anti-proliferative to HCC cell lines (SMMC7721 and Bel7402). Hispidulin activated caspase-3 and triggered apoptosis in HCC cells. Moreover, hispidulin inhibited cell migration and invasion by inhibiting the expression of matrix metalloproteinases (MMP-2, MMP-9) and by inducing tissue inhibitor of metalloproteinase-3 (TIMP-3) expression. Hispidulin activated peroxisome proliferator-activated receptor γ (PPARγ) signaling which mainly contributed to its cytotoxicity in HCC cells. Remarkably, GW9662 (a PPARγ inhibitor) or PPARγ targeting siRNA significantly abrogated the anti-proliferative, pro-apoptotic, and anti-metastatic effects of hispidulin in HCC cells. Furthermore, hispidulin induced activation of PPARγ which was associated with increased phosphorylation of AMPK, ERK, JNK in HCC cells. Compound C (an AMPK inhibitor) or PD98059 (a MEK inhibitor) partly reversed the effects of hispidulin on PPARγ signaling in HCC cells. In contrast, no significant changes in PPARγ signaling were observed in HCC cells pretreated with SP600125 (a JNK inhibitor), while SP6000125 significantly inhibited the anti-cancer effects of hispidulin in HCC cells. Hispidulin administration effectively suppressed Bel7402 xenograft tumor growth and lung metastasis in vivo. Our findings indicate that PPARγ activation by hispidulin effectively suppressed HCC cell growth and metastasis both in vitro and in vivo.
汉黄芩素是一种酚类黄酮,对多种人类癌症具有很强的细胞毒性。然而,汉黄芩素对肝细胞癌(HCC)的影响及其作用的潜在分子机制仍不清楚。本研究在实验模型中研究了汉黄芩素对 HCC 的影响,包括肿瘤细胞系和小鼠肿瘤异种移植。结果表明,汉黄芩素对 HCC 细胞系(SMMC7721 和 Bel7402)具有细胞毒性和抗增殖作用。汉黄芩素激活 caspase-3 并触发 HCC 细胞凋亡。此外,汉黄芩素通过抑制基质金属蛋白酶(MMP-2、MMP-9)的表达和诱导组织金属蛋白酶抑制剂-3(TIMP-3)的表达来抑制细胞迁移和侵袭。汉黄芩素激活过氧化物酶体增殖物激活受体 γ(PPARγ)信号通路,这主要有助于其在 HCC 细胞中的细胞毒性。值得注意的是,GW9662(PPARγ 抑制剂)或 PPARγ 靶向 siRNA 显著削弱了汉黄芩素在 HCC 细胞中的抗增殖、促凋亡和抗转移作用。此外,汉黄芩素诱导 PPARγ 的激活,这与 HCC 细胞中 AMPK、ERK、JNK 的磷酸化增加有关。化合物 C(AMPK 抑制剂)或 PD98059(MEK 抑制剂)部分逆转了汉黄芩素对 HCC 细胞中 PPARγ 信号的影响。相比之下,在 HCC 细胞中预先用 SP600125(JNK 抑制剂)处理后,PPARγ 信号没有明显变化,而 SP6000125 显著抑制了汉黄芩素在 HCC 细胞中的抗癌作用。汉黄芩素给药有效地抑制了体内 Bel7402 异种移植肿瘤的生长和肺转移。我们的研究结果表明,汉黄芩素通过激活 PPARγ 有效地抑制了 HCC 细胞在体外和体内的生长和转移。