FAK activity sustains intrinsic and acquired ovarian cancer resistance to platinum chemotherapy [KMF parental, KMF clone KT13 (FAK-/-), KT13 + GFP-FAK, KT13 + GFP-FAK R454, and KT13 + deltaGSK beta-catenin]

Gene copy number changes, cancer stem cell (CSC) increases, and platinum chemotherapy resistance contribute to poor prognosis in patients with recurrent high grade serous ovarian cancer (HGSOC). CSC phenotypes involving Wnt-b-catenin and aldehyde dehydrogenase activities, platinum resistance, and tumor initiating frequency are here associated with spontaneous genetic gains, including genes encoding KRAS, MYC and FAK, in a new murine model of ovarian cancer (KMF). Noncanonical FAK signaling was sufficient to sustain human and KMF tumorsphere proliferation, CSC survival, and platinum resistance. Increased FAK tyrosine phosphorylation occurred in HGSOC patient tumors surviving neo-adjuvant platinum and paclitaxel chemotherapy and platinum resistant tumorspheres acquired FAK dependence for growth. Importantly, combining a pharmacologic FAK inhibitor with platinum overcame chemoresistance and triggered apoptosis in vitro and in vivo. Knockout, rescue, genomic and transcriptomic analyses collectively identified more than 400 genes regulated along a FAK/b-catenin/Myc axis impacting stemness and DNA repair in HGSOC, with 66 genes gained in a majority of Cancer Genome Atlas samples. Together, these results support combinatorial testing of FAK inhibitors for the treatment of recurrent ovarian cancer. mRNA profiles of KMF parental, KMF clone KT13 (FAK-/-), KT13 + GFP-FAK, KT13 + GFP-FAK R454, and KT13 + deltaGSK beta-catenin cells were generated in triplicate using an Illumina NovaSeq 6000 Sequencing System

复发性高级别浆液性卵巢癌（high grade serous ovarian cancer, HGSOC）患者的不良预后与基因拷贝数变异、癌症干细胞（cancer stem cell, CSC）比例升高及铂类化疗耐药密切相关。本研究在新型卵巢癌小鼠模型KMF中发现，涉及Wnt-β-连环蛋白（Wnt-β-catenin）与乙醛脱氢酶（aldehyde dehydrogenase）活性的CSC表型、铂类耐药及肿瘤起始频率，与包括KRAS、MYC及FAK在内的基因发生自发遗传获得存在关联。非经典FAK信号通路足以维持人类及KMF模型肿瘤球的增殖、CSC存活与铂类化疗耐药性。在经新辅助铂类联合紫杉醇化疗后存活的HGSOC患者肿瘤组织中，FAK酪氨酸磷酸化水平升高；而铂类耐药的肿瘤球则获得了对FAK的生长依赖性。值得注意的是，将FAK抑制剂药物与铂类化疗联合使用，可在体外及体内逆转化疗耐药并诱导细胞凋亡。通过基因敲除、拯救实验、基因组及转录组分析，本研究共鉴定出400余个受FAK/β-连环蛋白/Myc信号轴调控的基因，这些基因参与调控HGSOC的干细胞干性与DNA修复过程，其中66个基因在大多数癌症基因组图谱（Cancer Genome Atlas）样本中存在遗传获得现象。综上，本研究结果支持开展FAK抑制剂联合疗法治疗复发性卵巢癌的临床试验。本研究利用Illumina NovaSeq 6000测序系统（Illumina NovaSeq 6000 Sequencing System）对KMF亲本细胞、KMF克隆株KT13（FAK基因敲除型，FAK-/-）、KT13+GFP-FAK、KT13+GFP-FAK R454及KT13+缺失GSK位点β-连环蛋白细胞进行了三次生物学重复的mRNA表达谱测序。