# E-cadherin–driven adherens junction reinforcement promotes spheroid-mediated invasion and progression in ALK–rearranged lung cancer chemoresistance

## TL;DR

This study shows how lung cancer cells become resistant to treatment by forming spheroids and strengthening cell adhesion through E-cadherin and EpCAM.

## Contribution

The study identifies E-cadherin and EpCAM as key drivers of chemoresistance through spheroid formation and cytoskeletal remodeling in ALK-rearranged lung cancer.

## Key findings

- Crizotinib-resistant H2228 cells form compact spheroids with upregulated E-cadherin and reinforced adherens junctions.
- E-cadherin knockdown disrupts spheroid architecture and partially restores drug sensitivity.
- Elevated E-cadherin and EpCAM expression in patient biopsies correlates with chemotherapy resistance.

## Abstract

Metastasis of cancer cells is driven by morphogenic changes that involve cytoskeletal remodeling and adherens junction reorganization. These cytoskeletal dynamics enable cancer cells to modulate their shape, adhesion, and motility, contributing to invasion, metastasis, and therapeutic resistance. In non–small cell lung cancer, anaplastic lymphoma kinase (ALK) gene rearrangements represent key oncogenic drivers, and ALK tyrosine kinase inhibitors such as crizotinib have significantly improved clinical outcomes. However, resistance frequently develops, often through on-target mutations or poorly understood bypass mechanisms. To investigate resistance–associated morphogenic adaptation, we employed two-dimensional and three-dimensional culture systems using crizotinib–resistant H2228 cells, along with transcriptomic profiling. The resistant cells formed compact, highly organized spheroids with upregulated E-cadherin expression and reinforced adherens junctions. This was accompanied by pronounced cytoskeleton-associated remodeling, characterized by enrichment of gene sets related to ruffle assembly, tissue morphogenesis, and the positive regulation of cell motility. Knockdown of E-cadherin disrupted spheroid architecture and partially restored crizotinib sensitivity, supporting its functional role in resistance. EpCAM was notably upregulated in peripheral protrusive cells and contributed to spheroid invasiveness in the resistant phenotype. Importantly, longitudinal biopsy samples from ALK-rearranged non–small cell lung cancer patients with cancer progression revealed elevated expression of E-cadherin and EpCAM during chemotherapy. It indicates the clinical relevance of adhesion–mediated morphogenic program impacting chemoresistance. Our findings suggest that bypass resistance is mediated, in part, by cytoskeleton–associated morphogenic plasticity that promotes spheroid formation, cell-cell adhesion, and invasive behavior. Targeting cytoskeletal remodeling and adherens junction dynamics may provide a novel therapeutic approach to overcome drug resistance in metastatic ALK–rearranged lung cancer.

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