Abstract 5986: Inverse relationship between Giant Axonal Neuropathy gene expression and EMT in human tumors

Abstract

Abstract Gigaxonin, the protein product of the Giant axonal neuropathy (GAN) gene, is a E3 ubiquitin ligase involved in neural cell and fibroblast intermediate filament processing. We have previously shown that Gigaxonin interacts with p16 in cisplatin-mediated ubiquitination of NF-κB. We analyzed cervical and head and neck cancer cell lines and primary tumors and have found exon 8 c.1293C>T single nucleotide polymorphism (SNP) to occur in both HPV positive and negative tumor cells lines and primary tumors. The prevalence of this SNP in the tumor samples was double that of the normal population (47.25% vs. 22%) and there was no relationship to HPV status. Cell lines containing the SNP showed higher expression of gigaxonin, and an inverse relationship to in vitro tumor cell line growth and cisplatin sensitivity. There was a direct relationship between the expression of gigaxonin and e-cadherin and inverse relationship to the expression of twist, snail and n-cadherin. CRISPR-Cas9 mediated conversion of T to C allele in gigaxonin overexpressing cervical cancer cell line ME 180 resulted in decreased gigaxonin expression accompanied by increased expression of twist, and snail and increased in vitro cell growth. Re-expression of gigaxonin in the CRISPR-Cas9 clone with a plasmid gigaxonin cDNA construct resulted in decreased expression of twist pointing to gigaxonin mediated downregulation of the EMT marker. We therefore hypothesize that GAN, associated with the neurodegenerative disease, is also a human tumor cell growth suppressor gene. Citation Format: Mysore S. Veena, Daniel Sanghoon Shin, Chan Jeong, Jenna R. Chatoff, Natarajan Venkatesan, Saroj K. Basak, David Gray, Sharon P. Wilczynski, Sharon P. Wilczynski, Steven J. Gray, Donald B. Kohn, Marilene B. Wang, Eri S. Srivatsan. Inverse relationship between Giant Axonal Neuropathy gene expression and EMT in human tumors [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 5986.