Abstract：
The pleiotropic effect of cancer-associated fibroblasts (CAFs) on tumour progression depends on the environment. circFARP1 is critical for CAFs-induced gemcitabine (GEM) resistance in pancreatic cancer. Its specific role and mechanism in non-small cell lung cancer (NSCLC) have not been reported yet. We prepared a cancer-associated fibroblasts-conditioned medium (CAF-CM) to incubate the A549 cells. Quantitative real-time polymerase chain reaction was used to detect RNA levels. We detected protein expression by immunohistochemistry, immunocytochemistry, western blot and immunofluorescence. We also detected the targeting impact between circFARP1, miR-338-3p and SRY-box transcription factor 4 (SOX4) by using dual-luciferase reporter and RNA pull-down assays. We determined cell proliferation, migration and invasion capabilities through Cell Counting Kit-8 and transwell assays. In addition, we measured tumour volume and weight in vivo by establishing a xenograft tumour model. CircFARP1 levels were remarkably high in the CAFs. The transfection experiments found that circFARP1 downregulation in CAFs caused migration, proliferation and invasion inhibition of CAFs and A549 cells, whereas inhibiting miR-38-3p or overexpressing SOX4 in CAFs could significantly reverse the inhibition. In vivo study in nude mice confirmed that CAFs could promote NSCLC tumour growth and knockdown of circFARP1 could inhibit tumour growth of NSCLC, whereas miR-38-3p downregulation or SOX4 overexpression could significantly reverse the inhibition. circFARP1 promotes NSCLC development by stimulating miR-338-3p/SOX4 signalling axis to regulate CAFs.
摘要：
癌症相关成纤维细胞（CAF）对肿瘤进展的多效性作用取决于环境。circFARP1对于胰腺癌中CAFs诱导的吉西他滨（GEM）耐药至关重要。其在非小细胞肺癌（NSCLC）中的具体作用和机制尚未见报道。我们制备了癌症相关的成纤维细胞条件培养基(CAF-CM)以孵育A549细胞。定量实时聚合酶链反应用于检测RNA水平。我们通过免疫组织化学检测蛋白表达，免疫细胞化学,免疫印迹和免疫荧光。我们还通过使用双荧光素酶报告基因和RNA下拉法检测了circFARP1，miR-338-3p和SRY-box转录因子4（SOX4）之间的靶向影响。我们确定了细胞增殖，通过细胞计数试剂盒-8和transwell测定的迁移和侵袭能力。此外,我们通过建立异种移植肿瘤模型来测量体内肿瘤的体积和重量。CircFARP1水平在CAF中非常高。转染实验发现CAFs中circFARP1下调导致迁移，抑制CAFs和A549细胞的增殖和侵袭，而在CAFs中抑制miR-38-3p或过表达SOX4可以显著逆转这种抑制作用。在裸鼠体内研究证实，CAFs可以促进NSCLC肿瘤生长，circFARP1敲低可以抑制NSCLC肿瘤生长，而miR-38-3p下调或SOX4过表达可显著逆转抑制。circFARP1通过刺激miR-338-3p/SOX4信号轴调节CAFs促进NSCLC发展。
