Abstract 548: The microRNA-10b targeted therapeutic, TTX-MC138, is effective in preclinical pancreatic adenocarcinoma

Abstract

Abstract Non-coding RNAs, such as miRNAs, represent promising targets for cancer therapy, given their role as critical players in oncogenic processes, including tumor initiation and progression, metastasis and therapeutic resistance. We and others demonstrated that miRNA-10b is a critical driver of tumor cell viability, especially in the metastatic setting. Based on this discovery, it became feasible to treat established metastatic cancer by inhibiting miR-10b. This was accomplished using a therapeutic, termed TTX-MC138, composed of antagomirs against miR-10b, conjugated to dextran-coated iron oxide nanoparticles. In our previous studies in murine models of metastatic breast cancer, we demonstrated the effectiveness of TTX-MC138 at preventing and eliminating existing metastases. Here, we describe the application of TTX-MC138 for the treatment of pancreatic adenocarcinoma. TTX-MC138 was administered weekly via intravenous injection into mice bearing orthotopic xenografts derived from human pancreatic adenocarcinoma cells. Tumor burden was measured by in vivo bioluminescence imaging. Animal survival, body weight, and tumor and metastatic burden at necropsy were also analyzed. Serum and tumor miR-10b expression, as well as global gene expression using RNA-seq were assessed to provide insight into target engagement and molecular function. Animals treated with vehicle or gemcitabine served as controls. Tumor growth rate was found to be significantly lower in animals treated with TTX-MC138 vs controls (p < 0.0001 for TTX-MC138 vs. PBS and vs. gemcitabine). Importantly, 40% of the animals treated with TTX-MC138 regressed their tumors completely as measured by bioluminescence imaging. Treatment continued for 10 weeks, after which the responding mice were monitored for disease recurrence without treatment for an additional 10 weeks. The animals showed evidence of continued weight gain and durable survival. They were sacrificed 10 weeks after treatment was discontinued, despite no evidence of morbidity, to perform necropsy. No tumors or metastases were found at the time of sacrifice. Gene expression analysis confirmed target engagement and molecular mechanism of action. Against the background of our earlier work, these studies provide further evidence of the potential of TTX-MC138 for cancer therapy and expand its relevance beyond metastatic breast cancer to also include pancreatic adenocarcinoma. Citation Format: Subrata Ghosh, Douglas Lazarus, Neil Robertson, Edward Crosier, Peter Liu, Zdravka Medarova. The microRNA-10b targeted therapeutic, TTX-MC138, is effective in preclinical pancreatic adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 548.