■Chidamide(CHI)是在中国开发的一种亚型选择性组蛋白去乙酰化酶抑制剂(HDACI),并被批准为激素受体阳性(HR)/人表皮生长因子受体2阴性(HER2-)晚期乳腺癌的二线治疗方法。然而,耐药性通常发生在长期用药后。本研究旨在研究诱导CHI耐药的特征,并探讨对化疗药物的潜在交叉耐药。
■将浓度逐渐增加的CHI添加到乳腺癌MCF7细胞中,以建立耐CHI的MCF7(MCF7-CHI-R)细胞系。进行细胞计数试剂盒-8(CCK-8)测定以检测CHI的半数最大抑制浓度(IC50)。集落形成用于确定增殖抑制率。Westernblot分析检测细胞周期相关蛋白的表达,凋亡,铁性凋亡,和组蛋白脱乙酰酶(HDAC)。流式细胞术用于分析细胞凋亡和细胞周期。
■与MCF7细胞相比,MCF7-CHI-R细胞的CHI的IC50值增加。CHI导致细胞周期停滞和铁凋亡,在MCF7-CHI-R细胞中未显示。此外,与MCF7细胞相比,MCF7-CHI-R细胞中HDAC活性降低,HDAC1和HDAC10可能参与CHI耐药。此外,MCF7-CHI-R细胞对吉西他滨(GEM)耐药,阿霉素(ADM),多西他赛(DXT),白蛋白结合型紫杉醇(nab-PTX)和紫杉醇(PTX)。
■建立了MCF7-CHI-R,并且抗铁凋亡途径的激活参与了MCF-CHI-R细胞的抗性。此外,MCF7-CHI-R细胞对GEM有抗性,ADM,DXT,nab-PTX和PTX。
UNASSIGNED: Chidamide (CHI) is a subtype-selective histone deacetylase inhibitor (HDACI) developed in China and approved as a second-line treatment combined with the aromatase inhibitor for hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer. However, drug resistance is commonly occurred after a long period of medication. This study aimed to investigate the characterization of induced resistance to CHI and explore the potential cross-resistance to chemotherapeutic agents.
UNASSIGNED: CHI with gradually increasing concentrations was added to breast cancer MCF7 cells to establish a CHI-resistant MCF7 (MCF7-CHI-R) cell line. Cell counting kit-8 (CCK-8) assays were performed to detect half-maximal inhibitory concentration (IC50) of CHI. Colony formation was used to determine the proliferation inhibition rate. Western blot analysis was conducted to detect expressions of protein related with cell cycle, apoptosis, ferroptosis, and histone deacetylase (HDAC). Flow cytometry was used to analyze apoptosis and cell cycle.
UNASSIGNED: The IC50 value of CHI of MCF7-CHI-R cells was increased in comparison with MCF7 cells. And CHI led to cell cycle arrest and ferroptosis, which were not exhibited in MCF7-CHI-R cells. Moreover, HDAC activity decreased in MCF7-CHI-R cells in comparison with MCF7 cells, and HDAC1 and HDAC10 might be involved in the resistance to CHI. In addition, MCF7-CHI-R cells were resistant to gemcitabine (GEM), doxorubicin (ADM), docetaxel (DXT), albumin-bound paclitaxel (nab-PTX) and paclitaxel (PTX).
UNASSIGNED: The MCF7-CHI-R was established and the anti-ferroptosis pathway activation was involved in the resistance of MCF-CHI-R cells. Also, MCF7-CHI-R cells were resistant to GEM, ADM, DXT, nab-PTX and PTX.