目的:由于化疗耐药,大多数患者无法治愈癌症。癌症相关成纤维细胞(CAFs)在癌症化疗耐药中起着至关重要的作用,但缺乏对化疗耐药肺癌的详细了解。在这项研究中,我们研究了程序性死亡配体1(PDL-1)作为CAF诱导的化疗耐药的潜在生物标志物,并评估了其在非小细胞肺癌(NSCLC)中的作用和潜在的化疗耐药机制.
方法:对NSCLC中多个组织的基因表达谱进行系统搜索,以确定传统成纤维细胞生物标志物和CAF分泌的原瘤细胞因子的表达强度。通过ELISA分析CAFs中的PDL-1表达,西方印迹,和流式细胞术。人细胞因子阵列用于鉴定从CAF分泌的特定细胞因子。使用CRISPR/Cas9敲低和包括MTT在内的各种功能测定来评估PDL-1在NSCLC化学抗性中的作用。细胞入侵,球体形成,和细胞凋亡。使用具有活细胞成像和免疫组织化学的共植入异种移植小鼠模型进行体内实验。
结果:我们证明化疗刺激的CAFs促进NSCLC细胞的致瘤和干细胞样特性,这有助于他们的化学抗性。随后,我们发现,PDL-1表达在化疗的CAFs中上调,并与不良预后相关.沉默PDL-1表达抑制CAFs促进干细胞样特性和肺癌细胞侵袭力的能力,有利于化学抗性。机械上,PDL-1在化疗治疗的CAFs中的上调导致肝细胞生长因子(HGF)分泌增加,刺激癌症进展,细胞入侵,和肺癌细胞的干性,同时抑制细胞凋亡。
结论:我们的结果表明,PDL-1阳性CAFs通过分泌升高的HGF来调节NSCLC细胞的干细胞样特性,从而促进化学抗性。我们的发现支持PDL-1在CAF中作为化疗反应生物标志物,并作为化疗耐药NSCLC的药物递送和治疗靶点。
A cure for cancer is out of reach for most patients due to chemoresistance. Cancer-associated fibroblasts (CAFs) play a vital role in cancer chemoresistance, but detailed understanding of the process particularly in chemoresistant lung cancer is lacking. In this study, we investigated programmed death-ligand 1 (PDL-1) as a potential biomarker for CAF-induced chemoresistance and evaluated its role and the underlying mechanisms of chemoresistance in non-small cell lung cancer (NSCLC).
A systemic search of gene expression profiles of multiple tissues in NSCLC was carried out to determine the expression intensities of traditional fibroblast biomarkers and CAF-secreted protumorigenic cytokines. PDL-1 expression in CAFs was analyzed by ELISA, Western blotting, and flow cytometry. Human cytokine array was used to identify specific cytokines secreted from CAFs. Role of PDL-1 in NSCLC chemoresistance was assessed using CRISPR/Cas9 knockdown and various functional assays including MTT, cell invasion, sphere formation, and cell apoptosis. In vivo experiments were conducted using a co-implantation xenograft mouse model with live cell imaging and immunohistochemistry.
We demonstrated that chemotherapy-stimulated CAFs promoted tumorigenic and stem cell-like properties of NSCLC cells, which contribute to their chemoresistance. Subsequently, we revealed that PDL-1 expression is upregulated in chemotherapy-treated CAFs and is associated with poor prognosis. Silencing PDL-1 expression suppressed CAFs\' ability to promote stem cell-like properties and invasiveness of lung cancer cells, favoring chemoresistance. Mechanistically, an upregulation of PDL-1 in chemotherapy-treated CAFs led to an increase in hepatocyte growth factor (HGF) secretion, which stimulates cancer progression, cell invasion, and stemness of lung cancer cells, while inhibiting apoptosis.
Our results show that PDL-1-positive CAFs modulate stem cell-like properties of NSCLC cells by secreting elevated HGF, thereby promoting chemoresistance. Our finding supports PDL-1 in CAFs as a chemotherapy response biomarker and as a drug delivery and therapeutic target for chemoresistant NSCLC.