Poster Presentation NSW State Cancer Conference 2023

Driver or passenger? Investigation of the T1010I MET mutation in a metastatic gastric cancer model (#140)

Ann-Katrin Piper 1 2 , Chelsea Penney 1 2 , Jacqueline Holliday 1 2 , Gary Tincknell 1 3 4 , Yafeng Ma 5 , Jay Perry 1 2 , Daniel Brungs 3 4 , Marie Ranson 1 2
  1. Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia
  2. School of Chemistry and Molecular Bioscience, University of Wollongong , Wollongong, NSW, Australia
  3. School of Medicine, University of Wollongong, Wollongong, NSW, Australia
  4. Illawarra Cancer Centre, Wollongong Hospital, Wollongong, NSW, Australia
  5. Centre for Circulating Tumour Cell Diagnostics & Research, Ingham Institute, Liverpool, NSW, Australia

Background: The mesenchymal-epithelial transition factor, c-Met, is a receptor tyrosine kinase implicated in cancer progression and metastasis. Somatic and germline mutations in the MET gene have been identified in various malignancies, including gastric cancer. The T1010I missense mutation in exon 14 has been proposed as a potential activating mutation, however, its role as a tumour driver mutation in gastric cancer remains unclear.

Aim: The aim of this study was to investigate the functional significance of the T1010I MET mutation in a gastric cancer cell model.

Methods: In this study we used our unique gastric circulating tumour cell line, UWG02CTC, with a known T1010I MET mutation, as a model for metastatic gastric cancer. We used the small molecule inhibitors AMG337 and Capmatinib to investigate downstream signalling effects of c-Met inhibition via Westernblot, as well as on cell proliferation, -invasion, and -survival in 2D and 3D cell culture models. As a comparison we used the commercially available gastric cancer cell line AGS, derived from a solid tumour and with no known MET mutations.

Results: Following treatment with AMG337 and Capmatinib, no significant differences in downstream signalling pathways, including PI3K/Akt and MAPK/ERK, were observed in either cell lines. Additionally, no differences in cell proliferation or survival were detected. The only setting in which we could see a significant effect of AMG337 treatment on the UWG02CTC cells, was in our organotypic cell invasion assay, where treated cells showed significantly reduced invasion into the matrix compared to untreated controls.

Conclusions: Our findings suggest that the T1010I MET mutation is unlikely to be the primary tumour driver mutation in our UWG02CTC line. The absence of downstream signalling alterations and functional discrepancies between T1010I MET mutant and AGS wild-type MET cells indicate that this mutation does not confer a significant advantage in terms of cell proliferation, invasion, or survival. A potential explanation for these observations could be that the T1010I mutation is a germ line alteration rather than a somatic mutation specific to the tumour. The organotypic invasion results suggest that in particular circumstances, UWG02CTCs are sensitive to c-Met inhibition, which may be due to altered c-Met activation during the process of tissue invasion.

This study highlights the importance of comprehensive characterization of genetic alterations in cancer cells and their functional to identify bona fide tumour driver mutations.