Abstract
Betaine, known as trimethylglycine, is a non-toxic natural substance reported to affect cancer cell responses. This study delves into the impact of betaine on the survival, proliferation, and invasion of oral squamous cell carcinoma (OSCC) cells in vitro. Human OSCC cells (HSC-4 and HSC-7) were subjected to varying concentrations of betaine, and their viability and proliferation were assessed through colourimetric MTT and colony-forming unit assays. Cell cycle progression and cell apoptosis were also investigated using flow cytometry, while cell migration and invasion were examined using a transwell migration assay, and the mRNA expression was evaluated by a quantitative polymerase chain reaction. Finally, proteomic analysis was conducted through liquid chromatography-tandem mass spectrometry on the extracted protein component of the cells. Results indicate that betaine effectively suppressed OSCC proliferation and colony formation. It triggered early apoptosis without disrupting cell cycle progression, reduced cell migration, and inhibited invasion. Betaine exposure led to significantly decreased mRNA levels of MMP1, MMP2, and MMP9 while downregulating FN1, a gene linked to epithelial-to-mesenchymal transition. Proteomic analysis revealed 9240 differentially expressed up/downregulated proteins in cells treated with betaine. The significantly upregulated proteins were associated with ATP-binding cassette (ABC) transporters, while the down-regulated proteins were associated with G protein-coupled receptors (GPCR) ligand binding. In conclusion, betaine exhibits potent anti-cancer properties by attenuating OSCC cell proliferation and mitigating invasion. Exploring this natural product as an adjunct for managing oral squamous cell carcinoma shows promise, although further investigations are needed to fully elucidate its functionality.