Abstract A60: Targeted disruption of PI3K/Akt/mTOR signaling pathway induces cell cycle arrest, apoptosis, and autophagy, and inhibits inflammation, invasion and angiogenesis of OSCC cells

Abstract

Abstract Purpose: The phosphoinositide-3-kinase (PI3K) pathway is frequently altered in human cancer. This has led to the development and study of novel PI3K inhibitors for targeted therapy and also to overcome resistance to radiotherapy. Method: The antitumor effects of PI3K inhibitors (PI-828, PI-103 and PX-866) in terms of cell proliferation, colony formation, induction of apoptosis, cell cycle arrest, invasion, autophagy, and pNF-κB/p65 translocation in SCC-4, SCC-9 and SCC-25 cells was studied by performing MTT, clonogenic, DAPI staining, propidium iodide staining, annexin-V binding, Matrigel invasion, acridine orange staining and immunofluorescence assay. Western blot assay was performed to assess the alteration in the expression of various proteins. Results: PI-828 and PI-103 treatment exhibited dose-dependent inhibition of growth and proliferation of OSCC cells with a concomitant induction of apoptosis, altered cell cycle regulation and decreased invasiveness (p <0.01). PX-866 induced apoptosis, cell cycle arrest, autophagy and a significant decrease in the invasiveness of oral cancer cells as compared to untreated cells (p <0.01). These compounds significantly reduced expression of COX-2, Cyclin-D and VEGF in the treated cells besides cytoplasmic accumulation of pNF-κB/p65 protein. In addition to PI3Kα, inactivation of downstream components, i.e., Akt and mTOR, was seen. Conclusion: PI3K inhibitors such as PI-103, PI-828 and PX-866 may be developed as potential chemotherapeutic agents for effective treatment of OSCC and other malignancies associated with activated PI3K/Akt pathway. Note: This abstract was not presented at the conference. Citation Format: Sadhna Aggarwal, Sarah John, Suresh C. Sharma, Satya N. Das. Targeted disruption of PI3K/Akt/mTOR signaling pathway induces cell cycle arrest, apoptosis, and autophagy, and inhibits inflammation, invasion and angiogenesis of OSCC cells [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr A60.