Abstract PO-041: Systemic screening of gene delivery methods in pancreatic ductal adenocarcinoma cells

Abstract Deaths in the United States due to Pancreatic Ductal Adenocarcinoma (PDAC) has risen steadily since 1990, and PDAC is expected to be the second leading cause of cancer death by 2025. Such a dismal prognosis is mainly attributed to the fact that tumors are detected too late for an effective treatment. Additionally, even when detected early, PDAC is challenging to treat with existing treatment options. Thus, there is a need for improved treatment strategies for pancreatic cancer patients. Great efforts have been made to develop and test new targets in various model systems such as tumor cell lines, tumor organoid models, and patient-derived xenografts (PDXs). We previously demonstrated a proof-of-principle of cellular reprogramming to pluripotent state to model PDAC progression and utilized it as a discovery tool for early detection markers for PDAC. However, reprogramming efficiency was remarkably low and it is, at least in part, attributed to uneven gene delivery efficiencies across cell types in human pancreatic normal and cancer cells. Intriguingly, classical ductal cell types were more resistant to transduction with conventional VSV-G-pseudotyped lentivirus (LeV) than squamous subtype pancreatic cancer. To better understand the susceptibility of different types of pancreatic cancer cells to viral transduction and improve the gene delivery efficiency, we analyzed transduction of LeV, Sendai Virus (SeV), and episomal vector transfection efficiencies in classical ductal and squamous cell types. We used human pancreatic duct epithelial and foreskin fibroblast cell lines as controls. We found that transduction efficiency of LeV in both types of PDAC cell lines are significantly lower compared to control cell lines and considerably higher in squamous type compared to classical ductal type. In contrast, transduction efficiency of SeV was similar for both classical ductal and squamous types of PDAC cell lines and significantly higher compared to LeV efficiency (90% vs 5-25% at MOI 1). We also found that nucleofection transfection efficiency of episomal vector is significantly higher in squamous cell type compared to classical ductal cells (67% vs 55%). This is significantly higher than transduction efficiency of LeV (25 and 5% at MOI 1 correspondingly) but lower compared to SeV transduction efficiency. Thus, both SeV and nucleofection delivery methods show higher efficiency compared to LeV and can be successfully used as gene delivery methods in PDAC cell lines. By completing this study, we can provide a tailored gene delivery method for pancreatic cancer, and this information can be harnessed for cellular reprograming of human PDAC as well as testing newly developing targets in other model systems in vitro and ex vivo.This work is supported by OHSU/CEDAR project award 68182-939-000. Citation Format: Dmytro Grygoryev, Taelor Ekstrom, Jason M. Link, Rosalie C. Sears, Jungsun Kim. Systemic screening of gene delivery methods in pancreatic ductal adenocarcinoma cells [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-041.