Autophagic flux modulates tumor heterogeneity and lineage plasticity in SCLC

Small cell lung cancer (SCLC) is characterized by significant heterogeneity and plasticity, contributing to its aggressive progression and therapy resistance. Autophagy, a conserved cellular process, is implicated in many cancers, but its role in SCLC remains unclear.

Using a genetically engineered mouse model (Rb1 ; Trp53 ; GFP-LC3-RFP-LC3△G), we tracked autophagic flux in vivo to investigate its effects on SCLC biology. Additional in vitro experiments were conducted to modulate autophagic flux in NE and non-NE SCLC cell lines.

Tumor subpopulations with high autophagic flux displayed increased proliferation, enhanced metastatic potential, and neuroendocrine (NE) characteristics. Conversely, low-autophagic flux subpopulations exhibited immune-related signals and non-NE traits. In vitro, increasing autophagy induced NE features in non-NE cell lines, while autophagy inhibition in NE cell lines promoted non-NE characteristics.

This study provides a novel model for investigating autophagy in vivo and underscores its critical role in driving SCLC heterogeneity and plasticity, offering potential therapeutic insights.