Article Text
Abstract
Objective Cell-cell (CC) and cell-matrix (CM) adhesions are essential for epithelial cell survival, yet dissociation-induced apoptosis is frequently circumvented in malignant cells.
Design We explored CC and CM dependence in 58 gastric cancer (GC) organoids by withdrawing either ROCK inhibitor, matrix or both to evaluate their tumorigenic potential in terms of apoptosis resistance, correlation with oncogenic driver mutations and clinical behaviour. We performed mechanistic studies to determine the role of diffuse-type GC drivers: ARHGAP fusions, RHOA and CDH1, in modulating CC (CCi) or CM (CMi) adhesion independence.
Results 97% of the tumour organoids were CMi, 66% were CCi and 52% were resistant to double withdrawal (CCi/CMi), while normal organoids were neither CMi nor CCi. Clinically, the CCi/CMi phenotype was associated with an infiltrative tumour edge and advanced tumour stage. Moreover, the CCi/CMi transcriptome signature was associated with poor patient survival when applied to three public GC datasets. CCi/CMi and CCi phenotypes were enriched in diffuse-type GC organoids, especially in those with oncogenic driver perturbation of RHO signalling via RHOA mutation or ARHGAP fusions. Inducible knockout of ARHGAP fusions in CCi/CMi tumour organoids led to resensitisation to CC/CM dissociation-induced apoptosis, upregulation of focal adhesion and tight junction genes, partial reversion to a more normal cystic phenotype and inhibited xenograft formation. Normal gastric organoids engineered with CDH1 or RHOA mutations became CMi or CCi, respectively.
Conclusions The CCi/CMi phenotype has a critical role in malignant transformation and tumour progression, offering new mechanistic information on RHO-ROCK pathway inhibition that contributes to GC pathogenicity.
- GASTRIC CANCER
- CELL ADHESION
- CELL MATRIX INTERACTION
- APOPTOSIS
Data availability statement
Data are available in a public, open access repository. The RNA sequencing data have been deposited into the European Genome-Phenome Archive with accession number EGAS00001006252 (https://www.ebi.ac.uk/ega/studies/EGAS00001006252). Application to a data access committee as a standard procedure in the ega for data access containing human genetic data is needed, for the use of data for medical research by bona fide researchers.
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Data availability statement
Data are available in a public, open access repository. The RNA sequencing data have been deposited into the European Genome-Phenome Archive with accession number EGAS00001006252 (https://www.ebi.ac.uk/ega/studies/EGAS00001006252). Application to a data access committee as a standard procedure in the ega for data access containing human genetic data is needed, for the use of data for medical research by bona fide researchers.
Footnotes
YT, PSWC and CSO contributed equally.
Correction notice This article has been corrected since it published Online First. The supplementary methods file has been replaced.
Contributors HHNY and SYL conceived, designed and supervised the study. YT, PSWC, CSO, SSKY, HHNY, SLH, WYT, DC, SPL, ASYC, SWY, HSH, STY and SYL collected data, performed experiments and/or analysed data. PSWC performed the ARHGAP fusion KO studies. CSO performed the CC and CM dependence assay in tumour organoids. YT and HCS performed the bioinformatics data analysis. SL contributed clinical data and samples. SM assisted with animal experiments. HHNY, SYL and YT wrote the manuscript with assistance from PSWC, CSO and ASC. All authors contributed comments and approval for the manuscript. HHNY and SYL are the guarantors.
Funding This work was substantially supported by a theme-based research grant (Project No. T12-710/16-R) from the Research Grants Council of the Hong Kong SAR, China, and partly supported by the Centre for Oncology and Immunology under the Health@InnoHK Initiative funded by the Innovation and Technology Commission, The Government of Hong Kong SAR, China. Functional characterisation of gastric organoids was partially supported by a General Research Fund (Project No. 17108616) from the Research Grants Council of the Hong Kong SAR, China.
Competing interests SYL and STY have received research sponsorships from Pfizer, Merck, Servier. The other authors declare no competing interests.
Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.
Provenance and peer review Not commissioned; externally peer reviewed.
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