A truncating mutation in the autophagy gene UVRAG drives inflammation and tumorigenesis in mice

Area of Science:

• Cell Biology
• Molecular Biology
• Cancer Research

Background:

• Aberrant autophagy is a significant risk factor for inflammatory diseases and cancer.
• The genetic basis and mechanisms underlying autophagy dysregulation remain incompletely understood.
• UVRAG is a candidate tumor suppressor implicated in autophagy, often truncated in cancers into UVRAGFS.

Purpose of the Study:

• To investigate the in vivo role of the truncated UVRAGFS variant in autophagy regulation.
• To elucidate the mechanisms by which UVRAGFS impacts inflammatory responses and tumorigenesis.
• To assess the therapeutic potential of promoting autophagy in susceptible individuals.

Main Methods:

• Generation of inducible UVRAGFS mutant mice (iUVRAGFS) for in vivo studies.
• Assessment of basal and induced autophagy levels in iUVRAGFS mice.
• Evaluation of inflammatory responses in models of sepsis, colitis, and colitis-associated cancer.
• Analysis of spontaneous tumorigenesis, β-catenin stabilization, and centrosome amplification in aged iUVRAGFS mice.

Main Results:

• iUVRAGFS mice exhibit normal basal autophagy but impaired starvation- and LPS-induced autophagy due to disrupted UVRAG-autophagy complex.
• These mice show heightened inflammatory responses in sepsis and colitis, mediated by NLRP3-inflammasome hyperactivation.
• iUVRAGFS mice develop increased spontaneous tumors with age, linked to autophagy suppression, β-catenin stabilization, and centrosome amplification.

Conclusions:

• UVRAG is a critical in vivo regulator of autophagy.
• The truncated UVRAGFS variant promotes inflammation and tumorigenesis by disrupting autophagy.
• Enhancing autophagy may offer a strategy for preventing or treating inflammatory diseases and cancer.