Abstract: Objective To investigate the expression characteristics, prognostic value, biological functions, and regulatory mechanism of COL7A1 on the PI3K/AKT signaling pathway in biliary tract cancer. Methods Using TCGA cholangiocarcinoma transcriptome data, differential expression analysis, Cox regression, and LASSO regression were performed to screen key prognostic genes. A COL7A1 stable knockdown model was established in HCCC-9810 cells. Cell proliferation, invasion, and migration were assessed by CCK-8, Transwell, and wound healing assays. A subcutaneous xenograft tumor model in nude mice was established to evaluate the effect of COL7A1 knockdown on tumor growth. Immunohistochemistry was used to detect CD8⁺ T cell infiltration. Western blotting was performed to detect the expression levels of AKT and p-AKT in cells to verify the regulatory effect of COL7A1 on the PI3K/AKT pathway. Results COL7A1 expression was significantly upregulated in cholangiocarcinoma tissues, and high expression was associated with poor patient prognosis. Knockdown of COL7A1 significantly inhibited the proliferation, invasion, and migration of HCCC-9810 cells, as well as the growth of subcutaneous xenograft tumors in nude mice. Following COL7A1 knockdown, CD8⁺ T cell infiltration in xenograft tissues was increased. At the cellular level, p-AKT phosphorylation levels were reduced after COL7A1 knockdown, while total AKT expression remained unchanged. Conclusion COL7A1 is highly expressed in biliary tract cancer and promotes tumor cell proliferation, invasion, migration, and in vivo tumorigenesis by positively regulating the phosphorylation of the PI3K/AKT pathway. Its expression level is negatively correlated with CD8⁺T cell infiltration, suggesting that COL7A1 may serve as a prognostic biomarker and therapeutic target for biliary tract cancer.

Key words: biliary tract cancer, COL7A1, PI3K/AKT signaling pathway, proliferation, invasion, prognosis

摘要： 目的 探究COL7A1在胆道肿瘤中的表达特征、预后价值、生物学功能及其对PI3K/AKT信号通路的调控机制。方法 利用TCGA胆管癌转录组数据,通过差异分析、Cox回归及LASSO回归筛选关键预后基因。在HCCC-9810细胞中构建COL7A1稳定敲低模型,通过CCK-8、Transwell及划痕实验检测细胞增殖、侵袭及迁移能力。建立裸鼠皮下移植瘤模型,评估COL7A1敲低对肿瘤生长的影响;采用免疫组化检测CD8⁺ T细胞浸润;通过Western blot检测细胞中AKT及p-AKT蛋白表达,验证COL7A1对PI3K/AKT通路的调控作用。结果 COL7A1在胆管癌组织中表达显著上调,高表达与患者不良预后相关。敲低COL7A1可显著抑制HCCC-9810细胞的增殖、侵袭及迁移能力,并抑制裸鼠皮下移植瘤生长。COL7A1敲低后移植瘤组织中CD8⁺T细胞浸润增多。细胞水平上,敲低COL7A1后p-AKT磷酸化水平降低,总AKT表达无变化。结论 COL7A1在胆道肿瘤中高表达,通过正向调控PI3K/AKT通路磷酸化促进肿瘤细胞增殖、侵袭、迁移及体内成瘤,并与CD8⁺ T细胞浸润呈负相关,有望成为胆道肿瘤的预后标志物及治疗靶点。

关键词: 胆道肿瘤, COL7A1, PI3K/AKT信号通路, 增殖, 侵袭, 预后