# Transforming tumoroids derived from ALK-positive pulmonary adenocarcinoma to squamous cell carcinoma in vivo

## TL;DR

Researchers created a long-term lung cancer tumoroid model from a patient with ALK-positive cancer, which unexpectedly transformed into squamous cell carcinoma in mice.

## Contribution

A novel ALK-positive tumoroid model (PDT-LUAD#119) was established, showing long-term culture and squamous transformation in vivo.

## Key findings

- PDT-LUAD#119 tumoroids were sensitive to multiple ALK tyrosine kinase inhibitors.
- Xenografts of PDT-LUAD#119 tumoroids developed into adenosquamous carcinoma with ALK-positive squamous cell carcinoma.
- The tumoroid model carries TP53 and EML4-ALK v3 mutations.

## Abstract

Approximately 3–5% of non-small cell lung cancers (NSCLC) harbor ALK fusion genes and may be responsive to anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors. There are only a few reports on cell lines with EML4-ALK variant 3 (v3) and tumoroids that can be subject to long-term culture (> 3 months). In this study, we established tumoroids (PDT-LUAD#119) from a patient with lung cancer harboring EML4-ALK that could be cultured for 12 months. Whole-exome sequencing and RNA sequencing analyses revealed TP53 mutations and an EML4-ALK v3 mutation. PDT-LUAD#119 lung tumoroids were sensitive to the ALK tyrosine kinase inhibitors (ALK TKIs) crizotinib, alectinib, entrectinib, and lorlatinib, similar to NCI-H3122 cells harboring EML4-ALK variant 1 (v1). Unexpectedly, clear squamous cell carcinoma and solid adenocarcinoma were observed in xenografts from PDT-LUAD#119 lung tumoroids, indicating adenosquamous carcinoma. Immunostaining revealed that the squamous cell carcinoma was ALK positive, suggesting a squamous transformation of the adenocarcinoma. Besides providing a novel cancer model to support basic research on ALK-positive lung cancer, PDT-LUAD#119 lung tumoroids will help elucidate the pathogenesis of adenosquamous carcinoma.

The online version contains supplementary material available at 10.1007/s13577-024-01085-8.