Apolipoprotein E is a Potential Biomarker for Predicting Cancer Prognosis and is Correlated with Immune Infiltration

Area of Science:

• Oncology
• Molecular Biology
• Immunology

Background:

• Apolipoprotein E (APOE) is a key protein in lipoprotein metabolism, implicated in tumor growth and metastasis.
• The pan-cancer role of APOE in cancer development and progression remains largely uninvestigated.
• Understanding APOE's function in diverse cancers is vital for personalized treatment and prognosis.

Purpose of the Study:

• To investigate the diagnostic and prognostic significance of APOE across 33 distinct cancer types.
• To analyze the correlation between APOE expression and tumor mutation burden (TMB), microsatellite instability (MSI), and tumor-infiltrating cells (TICs).
• To explore the impact of APOE on the tumor immune microenvironment and its underlying physiological functions via GSEA.

Main Methods:

• Pan-cancer analysis of APOE expression in tumor versus normal tissues.
• Correlation analysis with clinical data, TMB, MSI, and TIC abundance.
• Application of ESTIMATE and CIBERSORT algorithms for immune microenvironment assessment.
• Gene Set Enrichment Analysis (GSEA) to elucidate functional pathways.

Main Results:

• APOE expression significantly differed between cancer and normal tissues across multiple tumor types.
• APOE levels were associated with survival outcomes, TMB, MSI, and TIC abundance.
• APOE expression may predict response to certain cancer chemotherapies.

Conclusions:

• APOE is closely associated with tumor development and progression in a pan-cancer context.
• APOE demonstrates potential as a predictive biomarker for prognosis and immunotherapy response in cancer patients.
• Further research into APOE's role can inform novel therapeutic strategies.