Transcriptional Subtypes Resolve Tumor Heterogeneity and Identify Vulnerabilities to MEK Inhibition in Lung...

Area of Science:

• Oncology
• Genomics
• Molecular Biology

Background:

• Non-small cell lung cancer (NSCLC) is a leading cause of cancer mortality.
• Lung adenocarcinomas represent the majority of NSCLC cases.
• A significant portion of lung adenocarcinomas lack targeted therapies due to a scarcity of actionable driver mutations.

Purpose of the Study:

• To classify lung adenocarcinoma tumors based on molecular signaling similarities.
• To identify novel subgroups within lung adenocarcinomas lacking targeted therapies.
• To understand tumor heterogeneity and identify subtype-specific vulnerabilities.

Main Methods:

• Transcriptional data analysis from over 800 early- and advanced-stage lung adenocarcinoma patients.
• Identification and characterization of distinct tumor subtypes using pathway phenotypes.
• Validation of subtype stability using multi-regional intratumoral biopsies.
• Preclinical modeling and chemical library screening for drug response.

Main Results:

• Three robust lung adenocarcinoma subtypes were identified: mucinous, proliferative, and mesenchymal.
• These subtypes exhibit distinct pathway phenotypes and capture heterogeneity, even in tumors without known oncogenic drivers (e.g., KRAS, EGFR).
• Subtypes demonstrated stability despite divergent mutation evolution and were recapitulated in preclinical models.
• Differential subtype response to MEK pathway inhibition was observed, validating subtype-specific vulnerabilities.

Conclusions:

• Transcriptional subtypes of lung adenocarcinoma possess translational relevance for treatment strategies.
• Further exploration of these subtypes can potentially improve therapeutic outcomes for lung adenocarcinoma patients.
• Identification of subtype-specific vulnerabilities offers new avenues for targeted therapy development.