Pancreatic ductal adenocarcinoma (PDAC) typically presents as metastatic disease at diagnosis and remains refractory to treatment. Next-generation sequencing efforts have described the genomic landscape, classified molecular subtypes, and confirmed frequent alterations in major driver genes, with coexistent alterations in KRAS and TP53 correlating with the highest metastatic burden and poorest outcomes. However, translating this information to guide therapy remains a challenge. By integrating genomic analysis with an arrayed RNAi druggable genome screen and drug profiling of a KRAS/TP53 mutant PDAC cell line derived from a patient-derived xenograft (PDCL), we identified numerous targetable vulnerabilities that reveal both known and novel functional aspects of pancreatic cancer biology. A dependence on the general transcription and DNA repair factor TFIIH complex, particularly the XPB subunit and the CAK complex (CDK7/CyclinH/MAT1), was identified and further validated utilizing a panel of genomically subtyped KRAS mutant PDCLs. TFIIH function was inhibited with a covalent inhibitor of CDK7/12/13 (THZ1), a CDK7/CDK9 kinase inhibitor (SNS-032), and a covalent inhibitor of XPB (triptolide), which led to disruption of the protein stability of the RNA polymerase II subunit RPB1. Loss of RPB1 following TFIIH inhibition led to downregulation of key transcriptional effectors of KRAS-mutant signaling and negative regulators of apoptosis, including MCL1, XIAP, and CFLAR, initiating caspase-8 dependent apoptosis. All three drugs exhibited synergy in combination with a multivalent TRAIL, effectively reinforcing mitochondrial-mediated apoptosis. These findings present a novel combination therapy, with direct translational implications for current clinical trials on metastatic pancreatic cancer patients. Significance: This study utilizes functional genetic and pharmacological profiling of KRAS-mutant pancreatic adenocarcinoma to identify therapeutic strategies and finds that TFIIH inhibition synergizes with TRAIL to induce apoptosis in KRAS-driven pancreatic cancer.

中文翻译：

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TFIIH 的药理学靶向抑制 KRAS 突变型胰腺导管腺癌并与 TRAIL 协同作用

胰腺导管腺癌（PDAC）在诊断时通常表现为转移性疾病，并且仍然难以治疗。下一代测序工作已经描述了基因组景观，对分子亚型进行了分类，并确认了主要驱动基因的频繁变化，其中 KRAS 和 TP53 的共存变化与最高的转移负担和最差的结果相关。然而，将这些信息转化为指导治疗仍然是一个挑战。通过将基因组分析与阵列 RNAi 可药物基因组筛选以及源自患者异种移植物 (PDCL) 的 KRAS/TP53 突变 PDAC 细胞系的药物分析相结合，我们发现了许多可靶向的漏洞，这些漏洞揭示了胰腺癌的已知和新的功能方面生物学。利用一组基因组亚型 KRAS 突变体 PDCL 鉴定并进一步验证了对一般转录和 DNA 修复因子 TFIIH 复合物，特别是 XPB 亚基和 CAK 复合物 (CDK7/CyclinH/MAT1) 的依赖性。CDK7/12/13 (THZ1) 共价抑制剂、CDK7/CDK9 激酶抑制剂 (SNS-032) 和 XPB（雷公藤甲素）共价抑制剂可抑制 TFIIH 功能，从而破坏 TFIIH 的蛋白质稳定性RNA 聚合酶 II 亚基 RPB1。TFIIH 抑制后 RPB1 的缺失导致 KRAS 突变信号传导的关键转录效应子和细胞凋亡负调节因子（包括 MCL1、XIAP 和 CFLAR）下调，从而启动 caspase-8 依赖性细胞凋亡。所有三种药物与多价 TRAIL 组合都表现出协同作用，有效增强线粒体介导的细胞凋亡。这些发现提出了一种新颖的联合疗法，对当前转移性胰腺癌患者的临床试验具有直接的转化意义。意义：本研究利用 KRAS 突变型胰腺癌的功能遗传和药理学分析来确定治疗策略，并发现 TFIIH 抑制与 TRAIL 协同作用，诱导 KRAS 驱动的胰腺癌细胞凋亡。