Steroidal alkaloids isolated from Veratrum grandiflorum Loes. as novel Smoothened inhibitors with anti-proliferation effects on DAOY medulloblastoma cells
Steroidal alkaloids isolated from Veratrum grandiflorum Loes. as novel Smoothened inhibitors with anti-proliferation effects on DAOY medulloblastoma cells
复制标题
从藜芦中分离出的甾体生物碱。
DOI：
10.1016/j.bmc.2021.116166
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发表时间：
2021-04-25
影响因子：
3.5
通讯作者：
Ye, Yi Ping
中科院分区：
文献类型：
--
作者：
Gao, Li Juan;Zhang, Meng Zhen;Ye, Yi Ping
Hedgehog （Hh）通路的组成性激活与多种恶性肿瘤的发生发展密切相关，如髓母细胞瘤（MB）等肿瘤。因此，迫切需要Hh通路的小分子抑制剂。本研究从桔黄中分离分离了3种新的甾体生物碱：Delta(5) (20R, 24R) 23-氧-24-甲基索acongetidine、Delta(5) (20S, 24R) 23-氧-24-甲基索acongetidine和veralinine 3-o - α - l- rhamnopyranosyl-(1 - bbbb2)- β - d -glucopyranoside，以及6种已知的生物碱：20-epi-verazine、verazine、protoverine 15-(l)-2 '-methylbutyrate、菊苣、veramarine和β - 1-chaconine。双荧光素酶生物测定表明，所有化合物对sh - light 2细胞均有明显的抑制作用，IC50值为0.72 ~ 14.31 μ M。为了确定这些Hh通路抑制剂是否与Smoothened （Smo）蛋白（一种重要的癌蛋白，也是该通路的靶点）作用，我们优先进行了bodipy - cycloparamine （BC）竞争结合试验。通过荧光显微镜和流式细胞仪观察，与单独使用BC相比，所有化合物均明显降低了Smooverexpression HEK293T细胞中BC与Smo结合的荧光强度。通过直接与Smo相互作用，揭示了它们实际上是新型的天然Smo抑制剂。然后，对Hh通路高表达的典型儿童脑肿瘤细胞系人MB细胞系DAOY进行抗肿瘤作用研究。有趣的是，与vismodegib一样，大多数化合物在作用24 h后对DAOY细胞有轻微的增殖抑制作用，而β - 1-chaconine对DAOY生长的抑制作用最强，IC50值为5.35 μ m。综上所述，我们的研究为靶向治疗h依赖性肿瘤提供了几种新的天然Smo抑制剂。
Constitutive activation of Hedgehog (Hh) pathway is intimately related with the occurrence and development of several malignancies, such as medulloblastoma (MB) and other tumors. Therefore, small molecular inhibitors of Hh pathway are urgently needed. In this study, three new steroidal alkaloids, Delta(5) (20R, 24R) 23-oxo-24-methylsolacongetidine, Delta(5) (20S, 24R) 23-oxo-24-methylsolacongetidine and veralinine 3-O-alpha-L-rhamnopyranosyl-(1 -> 2)-beta-D-glucopyranoside, together with six known alkaloids, 20-epi-verazine, verazine, protoverine 15-(l)-2 '-methylbutyrate, jervine, veramarine and beta 1-chaconine, were isolated and determined from Veratrum grandiflorum Loes. The dual-luciferase bioassay indicated that all compounds exhibited significant inhibitions of Hh pathway with IC50 values of 0.72-14.31 mu M against Shh-LIGHT 2 cells. To determine whether these Hh pathway inhibitors act with the Smoothened (Smo) protein, which is an important oncoprotein and target for this pathway, BODIPY-cyclopamine (BC) competitive binding assay was preferentially performed. Compared with BC alone, all compounds obviously reduced the fluorescence intensities of BC binding with Smo in Smooverexpression HEK293T cells through fluorescence microscope and flow cytometer. By directly interacting with Smo, it revealed that they were actually novel natural Smo inhibitors. Then, their anti-tumor effects were investigated against the human MB cell line DAOY, which is a typical pediatric brain tumor cells line with highly expressed Hh pathway. Interestingly, most of compounds had slight proliferation inhibitions on DAOY cells after treatment for 24 h same as vismodegib, while beta 1-chaconine showed the strongest inhibitory effect on the growth of DAOY with IC50 value of 5.35 mu M. In conclusion, our studies valuably provide several novel natural Smo inhibitors for potential targeting treatment of Hh-dependent tumors.