Abstract 23: Precision medicine approaches to Fanconi anemia oral cancer personalized prevention and treatment

Abstract

Abstract There is an increased risk of oral cavity and other head and neck cancers as Fanconi patients live longer post transplantation. DNA repair defects in Fanconi patients contribute to “field effect” in this population, which causes frequent recurrences and often fatal, second primary oral malignancies. These developments show a need for translation of new basic science concepts for this patient population. We are examining the effects of both Metformin and Pioglitazone, and Polo kinase and Wee Kinase inhibitors in Fanconi anemia oral cancer cell lines, and leukoplakia control cells. We employed 3 FA oral cancer cell lines for the current study. We performed clonogenic and cell proliferation (MTT) experiments in replicates and repeated those experiments to establish initial dose responses of the inhibitors at biologically relevant concentrations. We used ANOVA analysis with a P<0.05 as our level of significance. Concurrently, we are examining pioglitazone-metformin signaling pathways in biopsies from precancerous oral lesion (non-FA) patients treated with pioglitazone in our multiple chemoprevention clinical trials via confocal fluorescence microscopy. We found both the Wee Kinase inhibitor and POLO kinase inhibitor resulted in dose dependent decreases in proliferation and clonogenic potential in several experiments in all cell lines. We observed decreased proliferation at 72 hours at clinically achievable serum levels of 75%. However, we also observed cytotoxic effects as well, as judged by MTT reading at 72 hours being lower than the original Day 0 MTT readings. Pioglitazone treatment also resulted in dose dependent decreases in cell proliferation and clonogenic potential at clinically achievable serum levels. Similar effects can be achieved with metformin, however, at higher doses. Additionally, we have identified surrogate endpoints as suitable pharmacodynamic readouts by IHC analysis of the cell lines. There are precision medicine treatments for FA-associated oral carcinoma and these are feasible, based on earlier promising results we present here. We are attempting to discover new treatment methodologies for these patients, as conventional agents and radiation therapy are often unacceptable, due to the DNA fragility of the patient population. In combination, these efforts support our future goals of chemoprevention in this underserved prevention population. Citation Format: Daniel K. Swenson, Beverly R. Wuertz, Mustafa M. Ali, Gretchen M. Unger, Frank G. Ondrey. Precision medicine approaches to Fanconi anemia oral cancer personalized prevention and treatment [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 23.