全面分析胃腺癌中 COL4s 的表达、预后和免疫浸润。

Comprehensive analysis of the expression, prognostic, and immune infiltration for COL4s in stomach adenocarcinoma.

机构信息

Department of Gastroenterology, Affiliated Hangzhou First People's Hospital, Westlake University School of Medicine, Hangzhou, China.

Hangzhou Institute of Digestive Diseases, Hangzhou, China.

出版信息

BMC Med Genomics. 2024 Jun 21;17(1):168. doi: 10.1186/s12920-024-01934-3.

DOI:10.1186/s12920-024-01934-3

PMID:38907304

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC11191235/

Abstract

BACKGROUND

Collagen (COL) genes, play a key role in tumor invasion and metastasis, are involved in tumor extracellular matrix (ECM)-receptor interactions and focal adhesion pathways. However, studies focusing on the diagnostic value of the COL4 family in stomach adenocarcinoma (STAD) are currently lacking.

METHODS

The TCGA database was employed to retrieve the clinical features and RNA sequencing expression profiles of patients with STAD. We conducted an investigation to examine the expression disparities between STAD and adjacent normal tissues. Kaplan-Meier survival analysis was utilized to assess their prognostic significance, while Spearman correlation analysis was employed to determine their association with immune checkpoint genes and immunomodulatory molecules. Furthermore, GO and KEGG analyses were performed on the COL4s-related genes, revealing potential biological pathways through gene set enrichment analysis (GSEA). Subsequently, we explored the extent of immune infiltration of the COL4 family in STAD using the TIMER database. Lastly, the expression levels of the COL4 family in STAD were further validated through quantitative PCR (qPCR) and western blot techniques.

RESULTS

The expression levels of COL4A1/2 were significantly upregulated, while COL4A5/6 were conspicuously downregulated in STAD. The survival analysis revealed that the upregulated COL4s indicated poorer overall survival, first progression and post-progression survival outcomes. Additionally, our findings demonstrated a positive correlation between the expressions of COL4A1/2/3/4 and the infiltration of immune cells, including CD8 + T cells, dendritic cells, macrophages, neutrophils and CD4 + T cells. Further correlation analysis uncovered a favorable association between the expression of COL4A1/2/3/4 and various crucial immunomodulatory molecules, immunological checkpoint molecules, and chemokines. Quantitative PCR analysis confirmed that the expression patterns of COL4A1/3/4/6 genes aligned with the finding from the TCGA database. However, gastric cancer cells exhibited downregulation of COL4A2. Consistently, the protein level of COL4A1 was elevated, whereas the protein level of COL4A2 was reduced in the gastric cancer cell lines.

CONCLUSION

COL4s could potentially serve as biomarkers for diagnosing and predicting the prognosis of STAD.

摘要

背景

胶原（COL）基因在肿瘤侵袭和转移中发挥关键作用，参与肿瘤细胞外基质（ECM）-受体相互作用和焦点黏附途径。然而，目前缺乏关于 COL4 家族在胃腺癌（STAD）中的诊断价值的研究。

方法

我们使用 TCGA 数据库检索了 STAD 患者的临床特征和 RNA 测序表达谱。我们进行了一项研究，以检查 STAD 与相邻正常组织之间的表达差异。Kaplan-Meier 生存分析用于评估其预后意义，Spearman 相关性分析用于确定它们与免疫检查点基因和免疫调节分子的关联。此外，我们对 COL4s 相关基因进行了 GO 和 KEGG 分析，通过基因集富集分析（GSEA）揭示了潜在的生物学途径。随后，我们使用 TIMER 数据库探索了 COL4 家族在 STAD 中的免疫浸润程度。最后，通过定量 PCR（qPCR）和 Western blot 技术进一步验证了 COL4 家族在 STAD 中的表达水平。

结果

COL4A1/2 的表达水平显著上调，而 COL4A5/6 在 STAD 中明显下调。生存分析表明，上调的 COL4s 提示整体生存率、首次进展和进展后生存率较差。此外，我们的研究结果表明，COL4A1/2/3/4 的表达与免疫细胞浸润之间呈正相关，包括 CD8+T 细胞、树突状细胞、巨噬细胞、中性粒细胞和 CD4+T 细胞。进一步的相关性分析显示，COL4A1/2/3/4 的表达与各种关键免疫调节分子、免疫检查点分子和趋化因子呈有利关联。定量 PCR 分析证实，COL4A1/3/4/6 基因的表达模式与 TCGA 数据库的发现一致。然而，胃癌细胞中 COL4A2 的表达下调。一致地，胃癌细胞系中 COL4A1 的蛋白水平升高，而 COL4A2 的蛋白水平降低。