Investigation of the correlation between AGRN expression and perineural invasion in colon cancer

Abstract

Background and purpose: Colon cancer is one of the most common gastrointestinal malignancies. According to the traditional view, the primary modes of transmission include direct dissemination, hematogenous metastasis, and lymph node metastasis. In recent years, the role of perineural invasion (PNI) in the spread and metastasis of tumors has received immense attention. However, there are still relatively few reports on the potential mechanisms and biomarkers of PNI occurrence and development in colon cancer.

Method: We identified genes linked to the onset and progression of PNI in colon cancer using bioinformatics tools and extensive databases. Gene function enrichment analysis was used to explore the potential roles of these genes in tumor proliferation, invasion, and PNI. A collection of postoperative pathological specimens from colon cancer patients who underwent surgery, related clinicopathological data, and immunohistochemistry were used to validate AGRN expression in PNI tissues.

Results: Bioinformatics analysis revealed that AGRN is overexpressed in colon cancer tissues and correlates with poor patient prognosis. The findings from gene association and enrichment studies indicate that AGRN and its associated genes may play a role in PNI development and progression in colon cancer by simultaneously enhancing tumor cell invasion and neural cell growth. Immunohistochemical analysis of clinical samples confirmed that AGRN expression is elevated in colon cancer tissues with PNI.

Conclusion: We found that AGRN is significantly overexpressed in colon cancer tissues exhibiting PNI and is linked to poor patient survival. AGRN and its related genes may contribute to PNI by promoting tumor cell invasion and neural cell growth. Hence, AGRN may play a crucial role in the initiation and progression of PNI in colon cancer.

Keywords: AGRN; bioinformatics; colon cancer; immunohistochemistry; perineural invasion.

FIGURE 1

PNI-related genes in colon cancer. (A) Volcano plot displaying the expression levels of PNI-associated genes in colon cancer tissue. (B) AGRN Kaplan-Meier curve. (C) Comparison of AGRN expression between tumor and normal tissues. (D) Comparison of AGRN gene expression between tumor tissues and matched adjacent normal tissues. (E). AUC Curve for Colon Cancer Prediction Based on AGRN Expression Levels. (F). The relationship between AGRN-related methylation levels and patient prognosis. (G). A mulberry plot depicting the association between AGRN and related clinical data.

FIGURE 2

The association between AGRN and tumor staging and pan-cancer analysis. Tumor stage with AGRN: (A) T stage, (B) N stage, (C) M stage, and (D) TNM stage. (E–F) AGRN pan-cancer analysis.

FIGURE 3

Immune infiltration analysis of AGRN in digestive system tumors using six different immune infiltration algorithms.

FIGURE 4

Gene expression correlation analysis. (A) A volcano plot depicting gene correlations centered on AGRN, with each point representing a gene and the color indicating the P-value. (B) Gene correlation heatmap is a detailed representation where blue lines denote negative correlations, and red lines indicate positive ones. (C–F) The correlation between AGRN and the expression levels of BCAR1, CIC, ECE1, and SDF4.

FIGURE 5

AGRN-associated genes and pathways display. (A) AGRN in the STRING database. (B–D) Pie and bar charts depicting pathways associated with AGRN-centered gene sets and their functional relationships. (E) Enrichment of genes with AGRN gene as the core gene in the Webgestalt database.

FIGURE 6

Gene set prognosis analysis. (A) Risk score curves. (B) Point plots of different survival states. (C) Heatmap of prognostic data for high-risk and low-risk groups. (D) KM curves. (E) ROC curves.

FIGURE 7

Immunohistochemical detection of AGRN. (A) PNI-negative tumor tissue. (B) AGRN immunohistochemical staining in PNI-negative cancer tissue, indicated by red arrows showing AGRN expression. (C) PNI-positive cancer tissue, with arrows highlighting nerve cells encircled by tumor cells. (D) AGRN immunohistochemical staining in PNI-positive cancer tissue, with arrows marking neural tissue. Seale bars = 50 μm. (E–F) KM curves showing overall OS (E) and DFS (F).