SLC2A3 promotes tumor progression through lactic acid-promoted TGF-β signaling pathway in oral squamous cell carcinoma

PLoS One. 2024 Apr 16;19(4):e0301724. doi: 10.1371/journal.pone.0301724. eCollection 2024.

Abstract

Backgrounds: Oral squamous cell carcinoma is a malignant tumor of the head and neck, and its molecular mechanism remains to be explored.

Methods: By analyzing the OSCC data from the TCGA database, we found that SLC2A3 is highly expressed in OSCC patients. The expression level of SLC2A3 was verified by RT-PCR and western blotting in OSCC cell lines. The function of SLC2A3 in OSCC cell lines and Lactic acid in SLC2A3-knockdown OSCC cells were detected by colony formation, CCK8, transwell, and wound healing assays. The effect of SLC2A3 on tumor growth and metastasis was tested in vivo. GSEA and Western blot were used to analyze and validate tumor phenotypes and signaling pathway molecules.

Results: We analyzed OSCC datasets in the TCGA database and found that SLC2A3 had abnormally high expression and was associated with poor prognosis. We also found that oral squamous cell carcinoma cells had increased proliferation, migration, invasion, EMT phenotype, and glycolysis due to SLC2A3 overexpression. Conversely, SLC2A3 knockdown had the opposite effect. Our in vivo experiments confirmed that SLC2A3 overexpression promoted tumor growth and metastasis while knockdown inhibited it. We also observed that high SLC2A3 expression led to EMT and the activation of the TGF-β signaling pathway, while knockdown inhibited it. Interestingly, exogenous lactic acid restored the EMT, proliferation, migration, and invasion abilities of oral cancer cells inhibited by knocking down SLC2A3.

Conclusions: Our study reveals that SLC2A3 expression was up-regulated in OSCC. SLC2A3 activates the TGF-β signaling pathway through lactic acid generated from glycolysis, thus regulating the biological behavior of OSCC.

MeSH terms

  • Carcinoma, Squamous Cell* / pathology
  • Cell Line, Tumor
  • Cell Movement / genetics
  • Cell Proliferation
  • Gene Expression Regulation, Neoplastic
  • Glucose Transporter Type 3 / genetics
  • Head and Neck Neoplasms* / genetics
  • Humans
  • Mouth Neoplasms* / pathology
  • Signal Transduction
  • Squamous Cell Carcinoma of Head and Neck / genetics
  • Transforming Growth Factor beta / metabolism

Substances

  • Transforming Growth Factor beta
  • SLC2A3 protein, human
  • Glucose Transporter Type 3

Grants and funding

The author(s) received no specific funding for this work.