Background: Cancer-associated fibroblasts (CAFs) are key mediators of metastatic progression in non-small cell lung cancer (NSCLC). Fibroblast activation protein (FAP) serves as the hallmark of CAF activation. However, the upstream regulation of FAP remains elusive, limiting stroma-targeted therapy development. Methods:68Ga-FAP inhibitor (FAPI)-04 PET/CT imaging was performed on 61 NSCLC patients to evaluate the clinical significance of FAP. CAFs and normal fibroblasts (NFs) were isolated from patient tissues. Bioinformatic analysis and qRT-PCR were employed to screen and validate miRNAs. Functional assays (CCK-8, collagen contraction, wound healing, transwell co-culture) were utilized to investigate the role of miR-624-5p in regulating fibroblast activation and the effects on the metastatic potential of NSCLC cells. The targeting relationship between miR-624-5p and FAP was validated using FISH, dual-luciferase assay, and Western blotting. Results:68Ga-FAPI-04 uptake was higher in advanced NSCLC (p< 0.001) and correlated with tumor size, lymph node metastases, and distant metastases (p< 0.05). Isolated primary CAFs significantly enhanced the migration and invasion of A549 and PC9 cells compared to NFs (p< 0.001). We identified miR-624-5p as a significantly downregulated miRNA in CAFs (p< 0.001). Functionally, miR-624-5p overexpression inhibited CAF proliferation and collagen contraction (p< 0.01) and reduced the proliferation, migration, and invasion capabilities of A549 and PC9 cells (p< 0.001). Mechanistically, miR-624-5p bound to FAP mRNA and negatively regulated FAP expression (p< 0.001), thus suppressing CAF activation and tumor metastasis. Conclusions: Our findings establish miR-624-5p as a novel upstream regulator that suppresses FAP expression, consequently inhibiting CAF activation and its pro-metastatic function. Targeting the miR-624-5p/FAP axis represents a promising therapeutic strategy for NSCLC metastasis.
背景：癌症相关成纤维细胞（CAFs）是非小细胞肺癌（NSCLC）转移进程中的关键介质。成纤维细胞活化蛋白（FAP）是CAF活化的标志物。然而，FAP的上游调控机制仍不明确，这限制了基质靶向治疗的开发。方法：对61例NSCLC患者进行68Ga-FAP抑制剂（FAPI）-04 PET/CT成像，以评估FAP的临床意义。从患者组织中分离CAFs和正常成纤维细胞（NFs）。采用生物信息学分析和qRT-PCR筛选并验证miRNAs。通过功能实验（CCK-8、胶原收缩、伤口愈合、transwell共培养）研究miR-624-5p在调控成纤维细胞活化中的作用及其对NSCLC细胞转移潜能的影响。利用FISH、双荧光素酶报告基因实验和Western blotting验证miR-624-5p与FAP之间的靶向关系。结果：晚期NSCLC中68Ga-FAPI-04摄取较高（p<0.001），并与肿瘤大小、淋巴结转移和远处转移相关（p<0.05）。与NFs相比，分离的原代CAFs显著增强了A549和PC9细胞的迁移和侵袭能力（p<0.001）。我们发现miR-624-5p在CAFs中表达显著下调（p<0.001）。功能上，过表达miR-624-5p抑制了CAF的增殖和胶原收缩（p<0.01），并降低了A549和PC9细胞的增殖、迁移和侵袭能力（p<0.001）。机制上，miR-624-5p结合FAP mRNA并负调控FAP表达（p<0.001），从而抑制CAF活化和肿瘤转移。结论：我们的研究确定miR-624-5p是一种新型的上游调控因子，可抑制FAP表达，进而抑制CAF活化及其促转移功能。靶向miR-624-5p/FAP轴是治疗NSCLC转移的潜在策略。
肿瘤(癌症)患者之家