Abstract 5685: MiR-345-5p attenuates pancreatic cancer metastasis through KLK7/E-Cad/β-Catenin/Rap1 axis
Authors: Natesh Nagabhishek Sirpu , Nethi Susheel Kumar , White Brianna M , Kaifi Jussuf T. , Batra Surinder K. , Mallapragada Surya , Rachagani Satyanarayana 
Published: March 2024

Abstract
Background: Pancreatic cancer (PC) is a highly lethal malignancy with a 5-year survival rate of 10.8%, primarily attributed to early invasion and metastasis. Epithelial-to-mesenchymal transition (EMT) plays a crucial role in the metastatic progression of PC. Existing therapies, such as Gemcitabine, Abraxane, and FOLFIRINOX, have limited efficacy, emphasizing the need for identifying molecular targets to enhance PC patient survival. Recent advancements in miRNA therapies show promise, but a detailed understanding of miRNAs regulating PC growth and metastasis remains elusive. This study aims to uncover the role of miR-345-5p in regulating PC metastasis.
Methods: A miRNA microarray analysis of KC mouse data identified miR-345-5P as one of the significantly down-regulated miRNA, targeting multiple metastasis-related genes. Expression of miR-345-5p in PC was assessed using published databases, validated through qPCR and ISH in PC cell lines, serum samples, and patient tissue. In vitro overexpression and in vivo assays elucidated the functional roles of miR-345-5p in PC metastasis. A computational approach and dual-luciferase assays were used to identify the target of miR-345-5p. Western blots, immunohistochemistry, and immunofluorescence were utilized to decipher miR-345-5p mediated molecular mechanisms.
Results: MiR-345-5p expression was downregulated in PC tissue, serum, and cell lines compared to non-tumor tissues. Restoring miR-345-5p reduced PC cell proliferation, migration, and invasion in vitro and in vivo. KLK 7 was confirmed as a direct target, and functional experiments revealed miR-345-5p's acting as a tumor-suppressor by inhibiting the E-Cad/B-catenin/Rap1 axis signaling pathway. MiR-345-5p overexpression stabilized the E-Cadherin-β-catenin complex, leading to reduced β-catenin accumulation in the nucleus and thus leading to declined transcription of crucial genes (C-myc, cyclin D1 & MMP7) responsible for PC progression. Given the pivotal role of the c-myc gene in metabolism, we performed a metabolomic analysis. The findings unveiled significant metabolic rewiring, marked by reductions in glucose and amino acid metabolism, attributable to decreased C-myc expression due to restoration of miR-345 in PC cells.
Conclusion: MiR-345-5p overexpression negatively regulates PC proliferation and EMT by directly targeting KLK7/E-Cad/β-catenin/Rap1 axis. Restoring miR-345-5p with standard care therapies could be a promising strategy for improving survival in metastatic PC patients.
Citation Format: Nagabhishek Sirpu Natesh, Susheel Kumar Nethi, Brianna M White, Jussuf T. Kaifi, Surinder K. Batra, Surya Mallapragada, Satyanarayana Rachagani. MiR-345-5p attenuates pancreatic cancer metastasis through KLK7/E-Cad/β-Catenin/Rap1 axis [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 5685.