Two Faces of NOTCH1 in Liver Cancer and Immunotherapy

Area of Science:

• Oncology
• Immunology
• Genetics

Background:

• NOTCH1 signaling plays a complex role in cancer development and immune response.
• Sex-based differences in cancer incidence and treatment outcomes are increasingly recognized.
• The interplay between NOTCH1, sex chromosomes, and the tumor immune microenvironment requires further elucidation.

Purpose of the Study:

• To investigate the sex-specific role of NOTCH1 expression in hepatocellular carcinoma (HCC).
• To determine the correlation between NOTCH1 levels, HCC tumorigenicity, and response to immune checkpoint inhibitors (ICIs).
• To elucidate the mechanisms by which NOTCH1 influences anti-tumor CD8+ T-cell responses in a sex-dependent manner.

Main Methods:

• Analysis of NOTCH1 expression levels in HCC patient cohorts stratified by sex.
• Correlation studies linking NOTCH1 expression with tumor characteristics and ICI treatment outcomes.
• Investigation of NOTCH1's impact on CD8+ T-cell function and immune escape mechanisms in male and female models.

Main Results:

• High NOTCH1 expression inversely correlates with HCC tumorigenicity in males, associated with better ICI response.
• In females, high NOTCH1 expression correlates with increased HCC incidence and poorer immunotherapy outcomes.
• Activated NOTCH1 promotes sex chromosome-dependent anti-tumor CD8+ T-cell responses in males, but drives immune escape in females.

Conclusions:

• NOTCH1 exhibits dichotomous roles in HCC pathogenesis and immune response, contingent on patient sex.
• Targeting NOTCH1 or understanding its sex-specific functions may offer novel therapeutic strategies for HCC.
• Sex chromosome-dependent mechanisms mediate NOTCH1's influence on tumor immunity and immunotherapy efficacy.