# Mendelian Randomization and Bioinformatics Analysis Reveal the Potential Protective Role of Metformin in Primary Liver Cancer

## TL;DR

This study suggests metformin may lower primary liver cancer risk by affecting metabolic and immune pathways, based on genetic and bioinformatics analyses.

## Contribution

The study provides novel evidence for metformin's protective role in PLC through MR and bioinformatics, identifying key genes and pathways.

## Key findings

- Metformin use is associated with reduced PLC risk (p = 0.026), but not HCC or ICC.
- Key genes like DDX52 and KIF11 are linked to PLC, with involvement in cGMP-PKG signaling and fatty acid metabolism.
- Metformin-related genes correlate with immune infiltration and drug sensitivity, suggesting therapeutic relevance.

## Abstract

Primary liver cancer (PLC) and metformin are not well understood to be associated. We conducted a Mendelian randomization (MR) analysis using genetic data from IEU OpenGWAS and FinnGen R10, with metformin as the exposure and PLC as the outcome. The inverse variance weighting (IVW) method was the primary analytical approach, with heterogeneity assessed by Cochran's Q test, pleiotropy by MR‐Egger intercept, and outliers by MR‐PRESSO. Bioinformatics analyses further explored potential mechanisms, including differential gene expression, protein–protein interactions (PPI), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, immune cell infiltration analysis, and drug sensitivity analysis. MR results demonstrated a significant association between metformin use and reduced risk of PLC (β = −5.6046, OR = 0.0037, p = 0.026), with a Benjamini‐Hochberg false discovery rate (FDR) adjusted p value of 0.13. However, no causal effect was observed for hepatocellular carcinoma (HCC) or intrahepatic cholangiocarcinoma (ICC). By cross‐referencing transcriptome data from the GEO database GSE241466 with metformin‐related gene loci, 34 overlapping genes were identified. Differentially expressed genes (DEGs) were filtered using |log2FC| > 0 and p < 0.05, with five hub genes (DDX52, KIF11, GCDH, MRPL45, and TICRR) being particularly prominent. Functional enrichment analysis revealed involvement in cGMP‐PKG signaling and fatty acid metabolism pathways. Further validation with GEPIA2, TIMER, and TISCH showed correlations between these genes and immune infiltration, while GSCA‐based drug sensitivity analysis suggested therapeutic relevance. In summary, these findings indicate that metformin may reduce PLC risk by modulating metabolic and immune‐related pathways, supporting its potential value as an adjunct therapeutic agent. However, further validation through large‐scale clinical and basic research is warranted.

Using two‐sample Mendelian randomization and bioinformatics, this study found metformin associated with reduced primary liver cancer (PLC) risk (p = 0.026), without links to HCC/ICC. Key genes (e.g., DDX52, KIF11) and pathways (cGMP‐PKG signaling, fatty acid metabolism) were identified. Results suggest metformin's protective role in PLC via metabolic and tumor‐suppressive mechanisms, warranting further investigation as a potential therapy.