Project Summary
Lung cancer is the leading cause of cancer-related mortality worldwide. Lung tumors driven by mutant KRAS
are among the most aggressive and refractory to treatment, due in part by KRAS-driven metabolic
reprogramming. Efforts to better understand the pathways regulating metabolic adaptations in oncogenic KRAS-
driven tumors will provide insight into lung cancer progression and identify vulnerabilities that could be
therapeutically targeted to improve patient survival. The Shaw lab recently showed the requirement of AMP-
activated protein kinase (AMPK) to promote the growth of oncogenic KRAS-driven non-small-cell lung cancer
(NSCLC). AMPK is a master regulator of cellular and organismal metabolism that acts as a sensor of cellular
energy by altering metabolism when energy levels are low. While the Shaw lab and others have demonstrated
that AMPK signaling provides cancer cells with flexibility to adapt to metabolic stresses, the epigenetic
mechanisms by which AMPK promotes metabolic alterations and lung tumor growth remain poorly understood.
Preliminary studies identified a de novo DNA methyltransferase as a novel substrate of AMPK. DNA methylation
is involved in many normal cellular processes and is abnormally distributed in cancer cells, contributing to some
of their aggressive characteristics. This proposal addresses the consequences of AMPK-dependent regulation
of the de novo DNA methyltransferase on DNA methylation, metabolic programs, and lung tumor growth. First,
this work aims to define the methylation profile controlled by the AMPK-dependent phosphorylated form of the
de novo DNA methyltransferase using whole-genome bisulfite sequencing, CUT&TAG, and RNA sequencing
assays. Tumorigenicity and Seahorse real-time cell metabolic analyses will determine whether this regulation
disrupts DNA methylation patterns in a manner that generates tumor-promoting epigenetic lesions and metabolic
alterations. Additionally, the generation of autochthonous KRAS-driven NSCLC mouse lines expressing
constitutive knock-in of the de novo DNA methyltransferase with a serine-to-alanine mutation at the putative
phosphor-acceptor-serine will enable testing whether regulation of the de novo DNA methyltransferase impacts
tumor initiation, growth, and metastasis. This work addresses a fundamental relationship between two hallmarks
of cancer and if successful would lead to the mechanistic connection between metabolic stresses tumor cells
face and how they may trigger sustained DNA methylation changes.