Abstract:

The malignant progression of colorectal cancer （CRC） is closely associated with abnormal activation of critical oncogenes. Analysis of the cancer genome atlas （TCGA） omics data revealed that DBNDD1 is significantly upregulated in CRC tissues， with its overexpression demonstrating a significant correlation with shorter overall patient survival. This study aimed to investigate the expression characteristics， biological functions， and clinical significance of DBNDD1 in CRC. The research integrated omics analysis with experimental validation， evaluating the prognostic relevance of DBNDD1 expression through the TCGA database， assessing migration， invasion capabilities （Transwell assay， wound healing assay）， and apoptosis levels （flow cytometry） in HCT116 cells following DBNDD1 knockdown using siRNA， and monitoring tumor growth and apoptosis changes （Ki-67 immunohistochemistry， TUNEL assay） in nude mouse xenograft models. Gene set enrichment analysis （GSEA） was further employed to explore associated signaling pathways and immune microenvironment regulatory mechanisms. The experimental results demonstrated that DBNDD1 knockdown suppressed migration and invasion capabilities of HCT116 cells while promoting apoptosis. Mechanistic analysis revealed significant enrichment of NF-κB and TNF signaling pathways in DBNDD1-overexpressing samples， along with close associations with immunosuppressive microenvironment features， including increased infiltration of M2 macrophages and regulatory T cells. These findings provide novel research directions for the development of clinical molecular biomarkers and targeted therapeutic strategies in colorectal cancer.

Key words: colorectal cancer, DBNDD1, tumor microenvironment, NF-κB signaling pathway, immune infiltration

摘要：

结直肠癌（colorectal cancer，CRC）的恶性进展与关键癌基因的异常激活密切相关。基于癌症基因组图谱（the cancer genome atlas，TCGA）组学数据库分析结果显示，DBNDD1基因在CRC组织中高表达，且与患者总生存期缩短存在显著相关性。探究了DBNDD1在CRC中的表达特征、生物学功能及临床意义。通过TCGA数据库评估DBNDD1表达与预后的关联性；利用siRNA敲低DBNDD1后检测HCT116细胞的迁移、侵袭能力（划痕实验、Transwell实验）及凋亡水平（流式细胞术）；构建裸鼠移植瘤模型观察肿瘤生长及凋亡变化（Ki-67免疫组化、TUNEL检测），并结合基因集富集分析（gene set enrichment analysis，GESA）探索相关信号通路及免疫微环境调控机制。实验结果表明，DBNDD1敲低可抑制HCT116细胞的迁移及侵袭能力，同时促进细胞凋亡。进一步的机制分析显示，DBNDD1高表达样本在NF-κB和TNF信号通路上呈现显著富集，并与免疫抑制微环境特征（如M2型巨噬细胞及调节性T细胞浸润增加）存在密切关联。研究结果可为结直肠癌的临床分子标志物开发及靶向干预策略提供参考。

关键词: 结直肠癌, DBNDD1, 肿瘤微环境, NF-κB信号通路, 免疫浸润