Humphrey, K. S. | Search bioRxiv

bioRxiv2025

HNF1A is a novel BRD4 target and critical for BET-inhibitor response in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is an exceedingly lethal cancer that lacks actionable molecular drivers, limiting precision treatment options. We previously identified the transcription factor, HNF1A, as a novel driver of tumorigenesis and pancreatic cancer stem cell (PCSC) properties in PDAC; however, HNF1A-targeting modalities do not currently exist. Here we show that HNF1A is a direct target of the epigenetic reader protein, BRD4, and its expression is exquisitely sensitive to BET-inhibitors (BETi), which inhibit PDAC cell proliferation and block PCSC-properties in a panel of HNF1A-expressing cell lines and patient-derived xenograft cells. Remarkably, we report that the antineoplastic activity of BETi/BRD4 knockdown can be overcome by restoration of HNF1A expression, but not by re-expression of canonical BETi target MYC. RNA-sequencing analyses revealed that a subset of BETi-responsive transcripts is dependent on HNF1A expression, including receptor tyrosine kinases (RTKs), regulators and ligands. Consistent with these data, we found that HNF1A restoration rescued EGFR/ERBB3-signaling and the protective effects of HNF1A restoration could be overcome with EGFR-inhibitors. Furthermore, we found that expressions of HNF1A, BRD4, and ERBB3 were strongly correlated across PDAC patient samples using multispectral immunofluorescence, supporting a connection between these players in PDAC biology, and high expression of ERBB3 associated with better survival, supporting the clinical importance of this network in patient outcomes. These findings demonstrate that BETi can be used to ablate HNF1A expression and that the inhibition of HNF1A is critical for BETi activity, while supporting HNF1A as novel therapeutic target in PDAC. SignificanceThis study demonstrates that the oncogenic transcription factor HNF1A is a direct target of BRD4, and that the ablation of HNF1A by BET-inhibitors is central to their antineoplastic activity in PDAC.

cancer biology↗

bioRxiv2025

Targeting FGFR4 Abrogates HNF1A-driven Metastasis in Pancreatic Ductal Adenocarcinoma

PurposeWe previously identified an oncogenic role for the transcription factor HNF1A in pancreatic ductal adenocarcinoma (PDAC). However, the role of HNF1A in the metastatic progression of PDAC remains unknown and targeting modalities for HNF1A -dependent phenotypes have yet to be identified. Experimental DesignTranswell chambers were used to assess the effects of HNF1A and FGFR4 modulation on the migration and invasion of ATCC and patient-derived PDAC cells in vitro. An intrasplenic injection xenograft model was used to evaluate the impact of HNF1A knockdown and overexpression on metastatic tumor burden. Single-cell RNA sequencing, tissue microarray (TMA) data, and UMAP spatial profiling were used to identify FGFR4 as an HNF1A target gene upregulated in metastatic cells. RNAi and two FGFR4 inhibiting modalities (H3B-6527 and U3- 1784) were utilized to demonstrate the efficacy of FGFR4 inhibiting agents at reducing HNF1A- driven metastasis. ResultsKnockdown of HNF1A significantly decreases and HNF1A overexpression significantly increases PDAC cell migration and invasion. In vivo studies show that HNF1A knockdown significantly abrogates metastasis, while overexpression significantly promotes metastasis. Single-cell RNAseq shows that FGFR4 is upregulated in metastatic PDAC cells and staining for HNF1A and FGFR4 in a PDAC TMA reveals significant correlation between HNF1A and FGFR4 in PDAC patients. Further, knockdown and inhibition of FGFR4 significantly decreases HNF1A- mediated cell migration and invasion, and blocks HNF1A-driven metastasis in vivo. ConclusionsThese findings demonstrate that HNF1A drives PDAC metastasis via upregulation of FGFR4, and FGFR4 inhibition is a potential mechanism to target metastasis in PDAC patients. Translational RelevancePancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies, made even more devastating when metastases overwhelm major organs. The vast majority of PDAC patients either present with metastases or will relapse with recurrent metastatic PDAC after primary tumor resection. Unfortunately, toxic and largely ineffective chemotherapies are currently the only approved treatment options for these patients and therefore there exists a critical and unmet clinical need for targeted therapies against pro-metastatic pathways in PDAC. In the current study, we identify HNF1A as an oncogenic transcription factor that drives metastasis in PDAC, and it does so through upregulation of the receptor tyrosine kinase FGFR4. Importantly, FGFR4 is a targetable vulnerability and treatment with an FGFR4 blocking antibody reduces HNF1A-driven metastasis. These findings suggest that FGFR4 inhibitors could be an efficacious treatment for PDAC patients for the prevention or delay of metastatic tumor development.

cancer biology↗