Abstract 1489: The role of EPAS1 and TEAD1 in gastric cancer liver metastasis

Abstract Gastric cancer ranks fifth in incidence and fourth for cancer-related mortality worldwide. While the liver is widely recognized as the leading site of metastasis in gastric cancer, the intricate mechanisms underpinning its tropism toward the liver and the hematogenous metastasis process remain poorly understood and demand further investigation. Hematogenous metastasis encompasses the generation of circulating tumor cells from the primary tumor site and their subsequent attachment to the metastatic niche. This process involves the transition between adherent and suspension states. In our investigation of anchorage dependency, we identified 20 transcription factors upregulated in suspension cells compared to adherent cells and 18 transcription factors upregulated in adherent cells relative to suspension cells, respectively. To investigate factors involved in gastric cancer metastasis, RNA sequencing of paired primary and metastatic tissue samples obtained from 15 patients diagnosed with advanced gastric cancer was conducted, which disclosed the selective upregulation of EPAS1 and TEAD1 in metastatic liver tissue compared to the matched primary tumor tissue and the metastatic tissue originating from other sites. Through in vitro analysis, we observed a portion of adherent cells transitioning into suspension cells when subjected to a hyperdense environment. We also observed cell reattachment upon harvesting and replating these suspension-state transited cells. Comparing EPAS1 and TEAD1 expression in these states unveiled increased expression of EPAS1 and TEAD1 in reattached cells relative to suspension-state cells. We established a gastric cancer metastasis mouse model introducing gastric cancer cells into the mouse circulatory system via intracardiac injection to validate our findings. In vivo imaging was utilized to confirm systemic metastasis. After fluorescence-based cell sorting, EPAS1 and TEAD1 expression in cancer cells collected from the blood, liver, and ovary were assessed. We detected higher expression of EPAS1 and TEAD1 in liver metastasis compared to the circulating tumor cells. Furthermore, EPAS1 and TEAD1 were upregulated in liver metastatic cancer cells compared to ovarian metastatic cancer cells. Our findings underscore EPAS1 and TEAD1 as pivotal factors governing gastric cancer liver tropism and metastasis, offering insights that may contribute to targeted interventions in the clinical landscape. Citation Format: DONG KI Lee, Hyun Woo Park, Jae-Ho Cheong, Heon Yung Gee. The role of EPAS1 and TEAD1 in gastric cancer liver metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1489.