Epigallocatechin-3-gallate potentiates curcumin’s ability to suppress uterine leiomyosarcoma cell growth and induce apoptosis
Epigallocatechin-3-gallate potentiates curcumin’s ability to suppress uterine leiomyosarcoma cell growth and induce apoptosis
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DOI：
10.1007/s10147-012-0387-7
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发表时间：
2013-06
影响因子：
3.3
通讯作者：
Akiko Kondo;Takashi Takeda;Bin Li;K. Tsuiji;M. Kitamura;Tze Fang Wong;N. Yaegashi
中科院分区：
文献类型：
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作者：
Akiko Kondo;Takashi Takeda;Bin Li;K. Tsuiji;M. Kitamura;Tze Fang Wong;N. Yaegashi
子宫平滑肌肉瘤(LMS)对标准化疗方案有不良反应。据报道，姜黄素和表没食子儿茶素没食子酸酯(EGCG)这两种天然化合物具有抗癌活性。我们先前曾报道，姜黄素通过靶向AKT-mTOR途径抑制子宫LMS细胞的增殖。然而，克服姜黄素生物利用度低的挑战仍然存在。MTS法检测EGCG、姜黄素及其联合作用对细胞生长的影响。Western blotting检测它们对AKT、mTOR和S6的影响。用裂解PARP特异性抗体Western blotting、caspase-3活性和TUNEL法检测细胞的凋亡。用分光光度法测细胞内姜黄素水平。用抗EGCG细胞表面受体67-kDa层粘连蛋白受体(67LR)的抗体研究该受体在EGCG增强姜黄素作用中的作用。联合用药抑制AKT、mTOR和S6的磷酸化，并在比先前报道的更低的姜黄素浓度下诱导细胞凋亡。EGCG促进姜黄素的掺入。联合应用67LR抗体可部分挽救细胞增殖抑制，但不参与EGCG促进细胞内姜黄素的掺入。结论EGCG通过促进细胞内姜黄素的掺入，显著降低抑制AKT-mTOR途径、抑制细胞增殖和诱导细胞凋亡所需的姜黄素浓度，但该过程不依赖于67LR。
BackgroundUterine leiomyosarcoma (LMS) has an unfavorable response to standard chemotherapeutic regimens. Two natural occurring compounds, curcumin and epigallocatechin gallate (EGCG), are reported to have anti-cancer activity. We previously reported that curcumin reduced uterine LMS cell proliferation by targeting the AKT–mTOR pathway. However, challenges remain in overcoming curcumin’s low bioavailability.MethodsThe human LMS cell line SKN was used. The effect of EGCG, curcumin or their combination on cell growth was detected by MTS assay. Their effect on AKT, mTOR, and S6 was detected by Western blotting. The induction of apoptosis was determined by Western blotting using cleaved-PARP specific antibody, caspase-3 activity and TUNEL assay. Intracellular curcumin level was determined by a spectrophotometric method. Antibody against EGCG cell surface receptor, 67-kDa laminin receptor (67LR), was used to investigate the role of the receptor in curcumin’s increased potency by EGCG.ResultsIn this study, we showed that the combination of EGCG and curcumin significantly reduced SKN cell proliferation more than either drug alone. The combination inhibited AKT, mTOR, and S6 phosphorylation, and induced apoptosis at a much lower curcumin concentration than previously reported. EGCG enhanced the incorporation of curcumin. 67LR antibody partially rescued cell proliferation suppression by the combination treatment, but was not involved in the EGCG-enhanced intracellular incorporation of curcumin.ConclusionsEGCG significantly lowered the concentration of curcumin required to inhibit the AKT–mTOR pathway, reduce cell proliferation and induce apoptosis in uterine LMS cells by enhancing intracellular incorporation of curcumin, but the process was independent of 67LR.