Anticancer potential of UDCA on GBM. Anticancer potential of UDCA on GBM

Glioblastoma multiforme (GBM) is the deadliest form of brain tumor with a median survival time of 15 months due to drug resistance. Ursodeoxycholic acid (UDCA) is approved of cancer suppressive potential in several tumors. Here we researched on the antitumor potential of UDCA on GBM. The CCK-8 and colony formation was used for detecting cell viability. RNA sequencing hinted transcriptional profile and pathways. PCR and western blot tested the change of related markers. Phenotype changes as cell cycle, apoptosis, MMP and ROS were measured. UDCA inhibited GBM cell viability in a dose- and time-dependent way. RNA sequencing results exhibited UDCA treatment was related to glioma progression and located on mitochondria and endoplasmic reticulum (ER). Cell cycle was arrested in G1 phase followed by caspase-independent apoptosis. UDCA led to decreased MMP, overproduction of ROS and ER stress. Three main stress sensors ATF6, IRE1αand PERK were activated in acute phase. Combining UDCA with bortezomib achieved a synergistic effect via enhancing PERK/ATF4/CHOP pathway and alleviating IRE1α activation. UDCA inhibited GBM progression and the combination with bortezomib achieved a synergistic effect via protracted ER stress. UDCA, alone or with combination of BTZ, presented a promising drug for GBM. Overall design: a total of 6 samples were analyzed including 3 control group (LN229-NC1,LN229-NC2,LN229-NC3) and 3 treatment group (LN229-U1,LN229-U2,LN229-U3)

多形性胶质母细胞瘤（Glioblastoma multiforme, GBM）是致死性最高的脑肿瘤亚型，因肿瘤耐药性问题，患者中位生存期仅为15个月。熊去氧胆酸（Ursodeoxycholic acid, UDCA）在多种肿瘤中已被证实具有抗肿瘤潜能。本研究探讨了UDCA对GBM的抗肿瘤作用。
本研究采用CCK-8法与集落形成实验检测细胞活力；通过RNA测序分析转录组特征及相关信号通路；利用聚合酶链反应（PCR）与蛋白质印迹法检测相关标志物的表达变化；并检测细胞周期、凋亡、线粒体膜电位（MMP）及活性氧（ROS）水平等表型改变。
实验结果显示，UDCA可呈剂量与时间依赖性抑制GBM细胞活力。RNA测序结果表明，UDCA处理与胶质瘤进展密切相关，且其作用靶点定位于线粒体与内质网（endoplasmic reticulum, ER）。细胞周期被阻滞于G1期，随后发生半胱天冬酶非依赖性凋亡。UDCA可降低线粒体膜电位、诱导活性氧过量生成及内质网应激。急性期激活了ATF6、IRE1α与PERK这三种主要的内质网应激感受器。将UDCA与硼替佐米（bortezomib, BTZ）联合使用时，可通过增强PERK/ATF4/CHOP通路并抑制IRE1α活化产生协同抗肿瘤效应。
综上，UDCA可抑制GBM进展，与硼替佐米联合使用可通过延长内质网应激实现协同抗肿瘤作用。UDCA单用或与BTZ联用均可作为GBM治疗的潜在候选药物。
整体实验设计：共分析6个样本，包括3个对照组（LN229-NC1、LN229-NC2、LN229-NC3）与3个处理组（LN229-U1、LN229-U2、LN229-U3）