目的:胰腺导管腺癌(PDAC)的高度异质性的细胞和分子组成不仅促进了异常侵袭性的肿瘤生物学,而且与目前的一刀切的对抗PDAC的治疗策略的概念相矛盾。因此,我们旨在利用以SMAD4缺乏和活化T细胞核因子高表达(SMAD4-/-/NFATc1High)为特征的临床相关分子PDAC亚组的肿瘤生物学意义和治疗脆弱性.
方法:分析转录组和临床数据,以确定SMAD4-/-/NFATc1高癌症的预后相关性。通过免疫沉淀研究了体外和体内致癌转录因子复合物的形成,邻近连接测定,并验证了交叉模型和物种。SMAD4状态对治疗靶向经典KRAS信号的影响通过全基因组基因表达分析和遗传扰动实验进行了机械破译和证实。分别。在患者来源的类器官和细胞以及转基因和原位PDAC模型中进行了新的定制治疗选择的验证。
结果:我们的发现确定了侵袭性和化疗耐药SMAD4-/-/NFATc1High亚组的肿瘤生物学特性。机械上,我们确定SMAD4缺陷是致癌NFATc1/SMAD3/cJUN转录因子复合物形成的分子先决条件,驱动RRM1/2的表达式。RRM1/2补充与代谢的吉西他滨直接竞争DNA链掺入的核苷库。通过丝裂原激活的蛋白激酶信号传导抑制(MEKi)分解NFATc1/SMAD3/cJUN复合物可使RRM1/2表达正常化,并与体内吉西他滨治疗协同作用以降低增殖指数。
结论:我们的结果表明,以SMAD4缺乏和致癌NFATc1/SMAD3/cJUN复合物形成为特征的PDAC暴露了对MEKi/吉西他滨联合治疗的敏感性。
The highly heterogeneous cellular and molecular makeup of pancreatic ductal adenocarcinoma (PDAC) not only fosters exceptionally aggressive tumor biology, but contradicts the current concept of one-size-fits-all therapeutic strategies to combat PDAC. Therefore, we aimed to exploit the tumor biological implication and therapeutic vulnerabilities of a clinically relevant molecular PDAC subgroup characterized by SMAD4 deficiency and high expression of the nuclear factor of activated T cells (SMAD4-/-/NFATc1High).
Transcriptomic and clinical data were analyzed to determine the prognostic relevance of SMAD4-/-/NFATc1High cancers. In vitro and in vivo oncogenic transcription factor complex formation was studied by immunoprecipitation, proximity ligation assays, and validated cross model and species. The impact of SMAD4 status on therapeutically targeting canonical KRAS signaling was mechanistically deciphered and corroborated by genome-wide gene expression analysis and genetic perturbation experiments, respectively. Validation of a novel tailored therapeutic option was conducted in patient-derived organoids and cells and transgenic as well as orthotopic PDAC models.
Our findings determined the tumor biology of an aggressive and chemotherapy-resistant SMAD4-/-/NFATc1High subgroup. Mechanistically, we identify SMAD4 deficiency as a molecular prerequisite for the formation of an oncogenic NFATc1/SMAD3/cJUN transcription factor complex, which drives the expression of RRM1/2. RRM1/2 replenishes nucleoside pools that directly compete with metabolized gemcitabine for DNA strand incorporation. Disassembly of the NFATc1/SMAD3/cJUN complex by mitogen-activated protein kinase signaling inhibition normalizes RRM1/2 expression and synergizes with gemcitabine treatment in vivo to reduce the proliferative index.
Our results suggest that PDAC characterized by SMAD4 deficiency and oncogenic NFATc1/SMAD3/cJUN complex formation exposes sensitivity to a mitogen-activated protein kinase signaling inhibition and gemcitabine combination therapy.