Zhang Kun, Song Haixing, Yang Ping, Dai Xiaozhen, Li Ya, Wang Lan, Du Jun, Pan Kejian, Zhang Tao
School of Biomedicine Sciences, Chengdu Medical College, Chengdu, 610500, China.
Cell Prolif. 2015 Apr;48(2):249-58. doi: 10.1111/cpr.12161. Epub 2015 Jan 21.
Expression of dishevelled-1 (DVL1) has recently been linked to cancer progression, however, its role in resistance to cancer therapy is unclear. In this study, we aimed to explore the function of DVL1 in paclitaxel-resistant human ovarian cancer cells.
The MTT assay was used to assess effects of DVL1 silencing on sensitivity of cells that were otherwise resistant to paclitaxel (Taxol). Western blotting and immunofluorescence staining were used to examine effects of DVL1 on AKT/GSK-3β/β-catenin signalling.
Dishevelled-1 was found to be over-expressed in a paclitaxel-resistant cell line derived from human ovarian cancer cell line A2780 (A2780/Taxol line) as well as parental A2780 cells. Down-regulation of DVL1 (using the inhibitor 3289-8625 or siRNA (siDVL1) against DVL1) sensitized A2780/Taxol cells to paclitaxel. Over-expression of DVL1 in A2780 cells increased protein levels of P-gp, BCRP and Bcl-2, which are known targets of β-catenin. Silencing DVL1 in A2780/Taxol cells also reduced levels of these proteins, and led to accumulation of β-catenin. In addition, DVL1 aberrantly activated AKT/GSK-3β/β-catenin signalling. Inactivation of AKT signalling attenuated DVL1-mediated inhibition of GSK-3β and accumulation of β-catenin, in both A2780 and A2780/Taxol cells.
Taken together, these results suggest that silencing DVL1 sensitized A2780/Taxol cells to paclitaxel, by down-regulating AKT/GSK-3β/β-catenin signalling, providing a novel strategy for chemosensitization of ovarian cancer to paclitaxel-induced cytotoxicity.
Dishevelled-1（DVL1）的表达最近被认为与癌症进展有关，然而，其在癌症治疗耐药性中的作用尚不清楚。在本研究中，我们旨在探讨DVL1在耐紫杉醇人卵巢癌细胞中的功能。
采用MTT法评估DVL1沉默对原本对紫杉醇（泰素）耐药的细胞敏感性的影响。蛋白质免疫印迹法和免疫荧光染色法用于检测DVL1对AKT/GSK-3β/β-连环蛋白信号通路的影响。
发现Dishevelled-1在源自人卵巢癌细胞系A2780的耐紫杉醇细胞系（A2780/泰素细胞系）以及亲代A2780细胞中过表达。下调DVL1（使用抑制剂3289-8625或针对DVL1的小干扰RNA（siDVL1））使A2780/泰素细胞对紫杉醇敏感。在A2780细胞中过表达DVL1会增加P-糖蛋白、乳腺癌耐药蛋白和Bcl-2的蛋白水平，这些都是已知的β-连环蛋白靶点。在A2780/泰素细胞中沉默DVL1也会降低这些蛋白的水平，并导致β-连环蛋白的积累。此外，DVL1异常激活AKT/GSK-3β/β-连环蛋白信号通路。在A2780和A2780/泰素细胞中，AKT信号通路的失活减弱了DVL1介导的对GSK-3β的抑制以及β-连环蛋白的积累。
综上所述，这些结果表明，沉默DVL1通过下调AKT/GSK-3β/β-连环蛋白信号通路使A2780/泰素细胞对紫杉醇敏感，为卵巢癌对紫杉醇诱导的细胞毒性进行化学增敏提供了一种新策略。
