# Modeling Pathways of Early Growth Dysregulation at the GEJ > **NIH NIH R01** · JOHNS HOPKINS UNIVERSITY · 2024 · $731,451 ## Abstract PROJECT SUMMARY Cellular biology of the human gastroesophageal junction cardia (GEJ-cardia) has been notoriously difficult to study, in particular due to a lack of biologically relevant GEJ-cardia-specific disease models. Based on known early genetic events in GEJ-cardia neoplasia, we generated wild-type (WT) and TP53/CDKN2A dual-knockout (DKO) 3-dimensional (3D) human GEJ-cardia-derived organoids using CRISPR-Cas9 genome editing. Notably, DKO organoids grew faster, became larger, exhibited de novo intestinal, metaplastic and dysplastic morphology, and consistently grew as xenografts in vivo. Interestingly, 2-D MALDI mass spectrometric imaging revealed a markedly abnormal lipidomic profile in DKO organoids, with platelet-activating factor (PTAF) and free fatty acids (FFAs) among the most-upregulated lipids. Intriguingly, several of these FFAs (stearic acid, lauric acid, cyclo acid, oleic acid, and palmitate) function as known ligands that stimulate HNF4A, a centrally important master transcription factor (MTF) implicated during early GEJ-cardia neoplastic evolution. We hypothesize that dysregulated FFA metabolism, acting via a novel lipid-epigenome crosstalk featuring MTF hyperactivation, causes abnormal growth, proliferation and differentiation at the human GEJ-cardia. This hypothesis will be tested by two Specific Aims. In Aim 1, we will first assess the biological effects of PTAF- PTAFR signaling in our early GEJ neoplasia organoid model, using either loss- or gain-of-function approaches, followed by an examination of phenotypes, morphology, and differentiation of GEJ-cardia organoids. Similarly, potential functions of candidate FFAs will be interrogated in GEJ-cardia organoids. Furthermore, we will establish the in vivo etiologic role of PTAF-PTAFR signaling as well as candidate FFAs in early GEJ-cardia neoplasia. In Aim 2, we will explore a novel crosstalk between lipid metabolism and epigenomic reprogramming by investigating the functional contributions of FFAs and PTAF to the epigenomic activity of HNF4A. Direct binding of FFAs and PTAF to HNF4A will be measured by competitive radiometric binding assays. The functional regulation by HNF4A of GEJ-cardia chromatin accessibility and activity will be interrogated using a palette of epigenomic sequencing approaches. Finally, we will perform spatial quantification of the abundance of HNF4A- activating FFAs and PTAF in both GEJ-cardia organoids and primary patient samples by conducting advanced histopathology-guided MALDI imaging analyses. These efforts in toto promise to define biological drivers promoting early GEJ-cardia neoplastic evolution and to elucidate a novel crosstalk between lipid metabolism and epigenomic reprogramming, thereby discovering precise molecular mechanisms underpinning GEJ-cardia dysplasia and early neoplastic transformation. Moreover, this project has the potential to uncover and validate candidate approaches toward prevention and early intervention in GEJ-cardia neoplas... ## Key facts - **NIH application ID:** 10796514 - **Project number:** 1R01DK135562-01A1 - **Recipient organization:** JOHNS HOPKINS UNIVERSITY - **Principal Investigator:** De-Chen Lin - **Activity code:** R01 (R01, R21, SBIR, etc.) - **Funding institute:** NIH - **Fiscal year:** 2024 - **Award amount:** $731,451 - **Award type:** 1 - **Project period:** 2024-05-01 → 2029-02-28 ## Primary source NIH RePORTER: https://reporter.nih.gov/project-details/10796514 ## Citation > US National Institutes of Health, RePORTER application 10796514, Modeling Pathways of Early Growth Dysregulation at the GEJ (1R01DK135562-01A1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10796514. Licensed CC0. --- *[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*