Role and Mechanism of BRIP1 in Anoikis Resistance of Gastric Cancer

TL;DR

This study explores how BRIP1 helps gastric cancer cells resist cell death and identifies it as a potential marker for predicting patient outcomes.

Contribution

The study introduces an eight-gene model and identifies BRIP1's role in anoikis resistance and its link to the PI3K/Akt pathway in gastric cancer.

Findings

BRIP1 is significantly overexpressed in gastric cancer tissues and cells.

BRIP1 promotes anoikis resistance by reducing reactive oxygen species and activating the PI3K/Akt pathway.

An eight-gene model was developed as an independent prognostic factor for gastric cancer patients.

Abstract

To assess the therapeutic relevance of BRIP1 in gastric cancer (GC), we examine its functional role in conferring resistance to anoikis within GC cells and elucidate the oncogenic signaling pathways modulated by BRIP1. By integrating the Cancer Genome Atlas (TCGA) and Gene Set Enrichment Analysis (GSEA) databases with Least Absolute Shrinkage and Selection Operator (LASSO) regression, a novel risk score to stratify GC patients based on prognosis was generated, and a significantly differentially expressed gene, BRIP1, was validated through reverse transcription quantitative polymerase chain reaction (RT-qPCR). Protein expression associated with apoptosis, cell cycle, and epithelial-mesenchymal transformation (EMT) was quantified via RT-qPCR and Western blot (WB). 5-Ethynyl-2′-deoxyuridine (EdU) and cell counting kit-8 (CCK-8) assays were conducted to quantify proliferative activity. The protein level in axillary tumor tissues of nude mice was detected by immunohistochemistry (IHC). We established an eight-gene anoikis-related prognostic risk assessment model (DUSP1, VCAN, P3H2, TXNIP, BRIP1, FGD6, GPX3, and RLN2) for GC. Multivariate Cox regression confirmed the risk score as an independent prognostic factor. Among these genes, BRIP1 showed significant differential expression between tumor and normal tissues, as well as normal gastric mucosal epithelial cells and GC cells. Mechanistically, BRIP1 conferred anoikis resistance to GC cells by suppressing the generation of reactive oxygen species (ROS). We found that the PI3K inhibitor LY294002 counteracted BRIP1-driven oncogenic effects, which was evidenced by restored expression of key regulators governing apoptosis, cell cycle progression, and EMT, in addition to suppressed proliferation in GC cells. BRIP1 is postulated to function upstream of the PI3K/Akt signaling cascade. This study establishes a risk scoring model and identifies BRIP1 as a potential prognostic marker for GC.

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