Abstract 3930: MCT1 as a potential target in the progression of oral premalignant dysplasia to invasive squamous cell carcinoma

Abstract

Abstract Introduction: Most oral squamous cell carcinomas (OSCC) progress through clinically identifiable stages, starting from premalignant epithelial dysplasia to early invasive OSCC. How cells transform from premalignant dysplasia to early invasive OSCC is unknown. High monocarboxylate transporter 1 (MCT1; SLC16A1) expression is correlated with poor outcomes in OSCC patients, where it is thought to promote tumor growth by supporting metabolic coupling between cancer cells and tumor stroma. Because expression of MCT1 is markedly increased in OSCC patients, we sought to determine if MCT1 played a role in the progression of oral dysplasia in early invasive OSCC. Methods: Immunohistochemistry (IHC) was used to evaluate changes in the levels of MCT1 expression across adjacent normal, dysplasia, and OSCC tissues to identify expression patterns during cancer progression. Genetic knockout (KO) of SLC16A1 via CRISPR/Cas9 and pharmacological blockade by the MCT1 inhibitor AZD3965 were used on OSCC (TR146) and dysplastic (DOK) cell lines. KO was confirmed by qRT-PCR and immunoblotting. MCT1-KO and AZD3965-treated cells were assayed for changes in cell invasion using Matrigel-coated transwell assays. Correlative changes in gene expression based on MCT1 staining and disease progression were also observed in adjacent normal, dysplasia, and OSCC regions in each tissue section using Nanostring GeoMx Digital Spatial Profiler. Results: Expression of MCT1 was directly correlated to the progression of disease from dysplasia to early superficially invasive OSCC relative to normal adjacent epithelium. KO of MCT1 significantly decreased the invasion of dysplastic and OSCC cell lines compared to the wild-type (parental) controls. AZD3965 also decreased invasion in the parental dysplastic and OSCC lines. To identify progressive changes in gene expression across normal, dysplasia, and early invasive OSCC, transcripts for cancer-related genes were quantified in the epithelial and stromal compartments from patient samples. Compared to the normal epithelium, upregulation in gene expression, including SLC16A1, was observed in the cell cycle and metabolic pathways in OSCC tissues. Conclusions: Our data suggest that MCT1 plays a key role in breaching of the basement membrane and facilitating tumor cell migration and invasion. Targeting MCT1 in oral dysplasia may prevent progression to OSCC in oral cancer patients. Citation Format: Ethan J. Wong, Ali Khammanivong, Ravi Maisuria, Erin B. Dickerson, Raj Gopalakrishnan. MCT1 as a potential target in the progression of oral premalignant dysplasia to invasive squamous cell carcinoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3930.