Abstract 176: Tetraspanins in oral squamous cell carcinoma

Abstract

Abstract Objectives: To (1) investigate the expression levels of several tetraspanins in oral cancer cells and tissues; (2) characterize the subpopulation of oral cancer cells with elevated CD82; and (3) investigate roles of the tetraspanins in oral cancer migration, invasion, and metastasis. Methods: The protein expression levels of tetraspanins CD82(KAI1), CD9, CD81(TAPA), and their associate protein EWI-2(IGSF8) were quantified in normal human gingival epithelial cells (SG) and oral cancer cells (CAL27 and SCC-25 cells) using western blotting and immunofluorescence staining and imaging. CAL27 CD82 knockout cells (CD82KO) were created by CRISPR/CAS-9, sorted by Fluorescent Activated Cell Sorting, and validated by western blotting. A wound healing assay was used to study the role of CD82 in oral cancer cell migration. CD82 perturbation of the CAL27 genome and proteome were evaluated using Microarray (Affymetrix) and TRAQ/TMT Based Differential Protein Expression Analysis (Thermo, mass spectrometer). Results: So far, we have found (1) CD82 is highly expressed in CAL27 cancer cells, but its expression is low in SG and SCC-25 cells; (2) CD82 is highly expressed in human tongue cancer tissues; (3) CD9 is highly expressed in CAL27 cells; (4) The expression levels of CD81 and IGSF8 are comparable in the three cancer cell lines; (5) CAL27 cancer cells migrate faster than normal SG cells; (6) Knockout of CD82 significantly decreases the migration rate of CAL27 cells, suggesting that CD82 promotes migration of these cancer cells. Conclusions: CD82 has varied expression in different oral cancer cell lines. Its expression is very high in CAL27 cancer cells. Knockout of CD82 in CAL27 cells significantly inhibits migration of these cells. Our study suggests that CD82 might be used as a biomarker for a subpopulation of oral cancer cells and that CD82 could be a target for therapeutic interventions. Acknowledgements: Supported in part by the 2017 UTHSC CORNET Award. Supported in part by the UTHSC College of Dentistry Alumni Endowment Fund and the Tennessee Dental Association Foundation. Citation Format: Kiran K. Reddi, Kenneth M. Anderson, Franklin Garcia-Godoy, Yanhui H. Zhang. Tetraspanins in oral squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 176.