LKB1 controls inflammatory potential through CRTC2-dependent histone acetylation

Area of Science:

• Oncology
• Molecular Biology
• Epigenetics

Background:

• Deregulated inflammation is a hallmark of tumors with liver kinase B1 (LKB1) mutations.
• The precise mechanisms connecting LKB1 mutations to inflammation are not well understood.

Purpose of the Study:

• To elucidate the molecular mechanisms by which LKB1 loss promotes inflammation.
• To identify epigenetic regulators involved in LKB1-mutant-driven inflammation.

Main Methods:

• Investigated the role of CREB-regulated transcription coactivator 2 (CRTC2) in LKB1-deficient cells.
• Analyzed cytokine and chemokine production in response to inflammatory stimuli.
• Examined histone acetylation marks (H3K27ac) at inflammatory gene loci using ChIP assays.
• Studied the salt-inducible kinases (SIKs) pathway.

Main Results:

• LKB1 mutations sensitize cells to inflammatory stimuli, increasing cytokine and chemokine production.
• LKB1 loss leads to elevated CRTC2-CREB signaling, driven by SIKs.
• CRTC2 collaborates with CBP/p300 to deposit H3K27ac marks at inflammatory gene loci, enhancing expression.
• A novel anti-inflammatory pathway regulated by LKB1 and CRTC2-dependent histone modifications was identified.

Conclusions:

• Deregulated CRTC2 signaling downstream of LKB1 loss is an epigenetic driver of inflammation in LKB1-mutant tumors.
• This pathway links metabolic and epigenetic states to cellular inflammatory potential.
• Understanding this mechanism offers new therapeutic avenues for LKB1-mutant cancers.