Abstract 5973: Targeting prolyl 4-hydroxylase subunit alpha 1 with a small molecule inhibitor, diethyl-pythiDC, reduces pancreatic ductal adenocarcinoma growth and metastasis
Authors: Afaq Farrukh , Khushman Mohd , Bajpai Prachi , Diffalha Sameer Al , Otali Dennis , Varambally Sooryanarayana , Manne Upender 
Published: March 2024

Background: Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease that has a 5-yearrelative survival rate of less than 9%. It is the fourth leading cause of cancer-associated mortality,and is projected to become the second leading cause of cancer-related deaths by 2030. Since most(~80%) PDACs are diagnosed at late stages (metastasized), there is an urgent need to identifymolecular determinants that regulate PDAC progression and serve as candidates for therapeutictargeting. Prolyl 4-hydroxylase subunit alpha 1 (P4HA1) is the major isoform overexpressed inmost cancers, including PDAC. In PDAC, high expression of P4HA1 is associated with tumorprogression and poor clinical outcomes. Thus, we investigated if targeting P4HA1 in PDAC witha small molecule inhibitor; diethyl-pythiDC, had an inhibitory effect on cell proliferation, tumorprogression/growth, and metastasis.

Methods: To demonstrate the therapeutic efficacy of diethyl-pythiDC, we performed MTT, colonyformation, wound healing, Transwell, and western blot assays in various PDAC cell lines. Tumorgrowth and metastasis was evaluated with xenografts in NOD/SCID/IL2γ receptor-null (NSG)mice. Additionally, expression of P4HA1 in human PDAC and in adjacent normal pancreatictissues was assessed.

Results: In human PDACs, there was elevated expression of P4HA1 protein relative to adjacentnormal pancreatic tissues. Treatment of various PDAC cells (S2VP10, MIA PaCa2, BxPC-3, andPANC-1) with diethyl-pythiDC reduced cell proliferation and colony formation, and inducedG2/M cell cycle arrest. Diethyl-pythiDC reduced migration and invasion of PDAC cells bymodulating epithelial-mesenchymal transition (EMT) markers (N-cadherin, E-cadherin, andvimentin). In addition, diethyl-pythiDC reduced the expression of argonaute-2 (AGO2), acomponent of microRNA biogenesis implicated in tumorigenesis, and its downstream target,matrix metalloproteinase (MMP1). In preclinical animal models of PDAC, diethyl-pythiDCreduced tumor growth and metastasis. Furthermore, in xenograft tumors, diethyl-pythiDCtreatment reduced the expression of AGO2, MMP1, and the proliferative marker, PCNA, andmodulated proteins of the EMT.

Conclusions: Treatment with diethyl-pythiDC reduces PDAC progression by decreasing cellproliferation, arresting cells in the G2/M phase, downregulating AGO2/MMP1 expression, andmodulating the EMT. These findings suggest that targeting P4HA1 by diethyl-pythiDC could be aviable strategy to improve treatment for PDACs, particularly those expressing high levels ofP4HA1. They also provide a basis to conduct clinical trials to assess the utility of targeting P4HA1by diethyl-pythiDC.

Citation Format: Farrukh Afaq, Mohd Khushman, Prachi Bajpai, Sameer Al Diffalha, Dennis Otali, Sooryanarayana Varambally, Upender Manne. Targeting prolyl 4-hydroxylase subunit alpha 1 with a small molecule inhibitor, diethyl-pythiDC, reduces pancreatic ductal adenocarcinoma growth and 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 5973.