Tumor loss-of-function mutations in STK11/LKB1 induce cachexia

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Cancer cachexia (CC) is a wasting syndrome affecting 50% of solid tumor patients, characterized by muscle and adipose tissue loss.
• Current CC management is hindered by a lack of reliable biomarkers and understanding of its underlying molecular drivers.
• Identifying molecules that drive CC phenotype is crucial for developing effective therapeutic strategies.

Purpose of the Study:

• To identify molecular drivers of cancer cachexia (CC) by analyzing human non-small cell lung cancer (NSCLC) lines.
• To investigate the role of serine/threonine kinase 11 (STK11/LKB1) in the development of CC.
• To establish STK11/LKB1 mutations as a potential genetic biomarker for CC.

Main Methods:

• Injected 54 human NSCLC lines into immunodeficient mice to observe cachexia phenotypes.
• Performed whole-exome sequencing on cachectic and non-cachectic tumor lines to identify genetic mutations.
• Utilized gene silencing techniques to assess the impact of STK11/LKB1 on CC development in both NSCLC and murine colorectal carcinoma models.
• Analyzed circulating tumor DNA from NSCLC patients to correlate STK11/LKB1 mutations with weight loss.

Main Results:

• Mutations in STK11/LKB1 were found in 8 of 10 cachexia-inducing NSCLC lines, but none of the non-cachexia lines.
• Silencing STK11/LKB1 in cancer cells induced a cachexia phenotype in transplanted models.
• Tumor STK11/LKB1 loss of function altered the tumor microenvironment's immune cell repertoire, increasing CC-associated cytokines.
• An 89% concordance was observed between STK11/LKB1 mutations in circulating tumor DNA and weight loss in NSCLC patients.

Conclusions:

• Tumor loss of function in STK11/LKB1 is a key driver of cancer cachexia.
• STK11/LKB1 mutations can serve as a predictive genetic biomarker for cancer cachexia in patients.
• These findings provide a molecular basis for CC and offer a potential diagnostic tool.