Abstract 1210: NFX1-123: A potential therapeutic target in cancer

Abstract Background: NFX1-123 is the longer splice variant isoform of the NFX1 gene and is highly expressed in cervical cancer. Cervical cancer is caused by high-risk HPV infections, and NFX1-123 is a protein partner with the HPV oncoprotein E6. Together, NFX1-123 and E6 affect cellular growth, longevity, differentiation, and the immune response. The expression status of NFX1-123 in cancers beyond cervical cancer, and its potential as therapeutic target, has not been investigated. Methods: TSVdb of TCGA was used to quantify NFX1-123 expression in 25 primary cancers tissues compared to adjacent normal tissues. The NFX1-123 protein structure was predicted using I-TASSER: Interactive Threading ASSEmbly Refinement tool. The modeled structure was submitted to the MTi-Openscreen Virtual screening web-server using ZINC-Database to retrieve suitable drug molecules, and further screening was evaluated by PyRx interphase and AutoDock Vina. The top four compounds, found to bind in silico to NFX1-123, were tested experimentally to determine their inhibitory effects on NFX1-123-related cellular growth and survival by MTT assay. Results: 44% of cancers (11 of 25) had significant differences in NFX1-123 expression when compared to adjacent normal solid tissues. Nine of 11 cancers (88%) had greater NFX1-123 expression: breast invasive carcinoma, cholangiocarcinoma, colon adenocarcinoma, renal cell carcinoma, renal papillary cell carcinoma, hepatocellular carcinoma, lung adenocarcinoma, sarcoma, and stomach adenocarcinoma. Two of 11 cancers (18%) had reduced NFX1-123 expression: lung squamous cell carcinoma, and pheochromocytoma and paraganglioma. Additionally, HPV+ head and neck cancers had greater expression of NFX1-123 compared to HPV- head and neck cancers. Bioinformatics and proteomic predictive analysis revealed the 3-D structure of the NFX1-123; with this structure, drug libraries were screened for high binding affinity compounds. 17 drugs with binding energies range from -11.3 to -10 Kcal/mol. were found. The top four compounds were used to treat HPV- and HPV+ cervical and head and neck cancer cell lines in culture, and two (R428 and Ketoconazole) were found to reduce NFX1-123 protein levels and inhibit cell growth and survival. R428 was also found to inhibit NFX1-123 and regulate autophagy and autophagy-mediated cell death. Conclusion: Nine out of 25 (36%) cancers expressed high levels of NFX1-123, and drug targeting of NFX1-123 can lead to cell growth inhibition. NFX1-123 may be a potential novel therapeutic target in cancers that highly express NFX1-123. Citation Format: Sreenivasulu Chintala, Anand Anbarasu, Rachel A. Katzenellenbogen. NFX1-123: A potential therapeutic target in cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1210.