# Unveiling hypoxic regulatory networks by bioinformatics: mechanisms of hypoxia-related hub genes driving rituximab resistance and poor prognosis in DLBCL

## TL;DR

This study identifies hypoxia-related genes linked to rituximab resistance in DLBCL, offering new targets for improving treatment outcomes in high-risk patients.

## Contribution

The study identifies novel hypoxia-related hub genes associated with rituximab resistance and poor prognosis in DLBCL.

## Key findings

- 58 overlapping genes were identified between DLBCL-signature genes and hypoxia-related genes.
- Genes like LGALS1, TIMP1, ANXA1, and STAP1 were significantly associated with overall survival in rituximab-treated DLBCL patients.
- Functional analysis linked these genes to BCR and PI3K-AKT signaling pathways, suggesting roles in therapeutic resistance.

## Abstract

Diffuse large B-cell lymphoma (DLBCL), an aggressive subtype of non-Hodgkin lymphoma, exhibits heterogeneous clinical outcomes. While rituximab, a CD20 inhibitor, combined with chemotherapy has improved survival in some patients, resistance remains prevalent, particularly in hypoxic tumor microenvironments. Understanding hypoxia-related genes (HRGs) and their role in rituximab resistance is critical to addressing therapeutic challenges in high-risk DLBCL.

Gene expression profiles from GEO datasets (GSE56315: DLBCL tumor vs. normal; GSE104212: hypoxia-treated DLBCL cell lines) were analyzed to identify overlapping genes between DLBCL-signature genes (DSGs) and HRGs. protein interaction network topology analysis and Lasso regression modeling of TCGA-DLBC dataset were employed to screen regulator and hub genes. Hub genes linked to rituximab response and survival were validated in DLBCL patients receiving rituximab therapy. Functional enrichment analysis was used to explore associated pathways. The expression of the identified regulator and hub genes was validated using reverse transcription quantitative polymerase chain reaction (RT-qPCR).

58 overlapping genes were identified between DSGs and HRGs. PPI network and Lasso regression revealed 5 MS4A1 regulator genes and 10 hub genes. Among these, LGALS1 (HR = 0.588, p = 0.00085), TIMP1 (HR = 0.591, p = 0.00098), ANXA1 (HR = 0.614, p=0.0024) and STAP1 (HR = 0.633, p=0.0035) were significantly associated with overall survival and GPNMB (AUC = 0.869), CDCA7 (AUC = 0.686), and STAP1 (AUC = 0.663) associated with treatment response in rituximab-treated patients. Functional analysis implicated these genes in B-cell receptor (BCR) and PI3K-AKT signaling pathways, suggesting their mechanistic roles in therapeutic resistance.

This study identifies hypoxia-associated genes critical to rituximab resistance in DLBCL, highlighting potential therapeutic targets. Their involvement in BCR and PI3K-AKT pathways underscores novel vulnerabilities for overcoming refractory disease. Our findings provide a foundation for developing strategies to improve outcomes in high-risk DLBCL patients with hypoxic microenvironments.