Antitumor effects of a lectin purified from Genipa americana in human cancer cell lines and murine melanoma cells.

BACKGROUND: Plant lectins have attracted considerable interest because of their selective interactions with tumor-associated glycans and their potential antitumor properties. However, the effects of the lectin isolated from the bark of Genipa americana (GaBL) on different cancer cell models remain unknown. Therefore, this study aimed to evaluate the effects of GaBL on the phenotypes of human epidermoid carcinoma (A431), human tongue squamous cell carcinoma (SCC9), and murine metastatic melanoma (B16) cells. METHODS: Cancer cell lines were treated with 10 µg/ml of GaBL to assess cell viability, cell migration and invasion, as well as the identification of cell membrane alterations associated with apoptosis. Real-time polymerase chain reaction for caspase-3 was performed to verify if apoptosis is activated by lectin treatment. The mRNA expression of proteins (E-cadherin, type I collagen) related to the epithelial-mesenchymal transition was also analyzed. RESULTS: GaBL decreased (27.5-50%) cell proliferation and reduced cell migration in all strains evaluated. Additionally, the lectin decreased the invasion of SCC9 cells. Apoptosis was higher against B16 and SCC9 cells treated with the lectin. GaBL induced increased mRNA expression of caspase-3, E-cadherin, together with reduced type I collagen mRNA expression in the evaluated cell lines. GaBL inhibits growth, migration, and invasion of human head and neck cancer cells and modulates the expression of genes associated with apoptosis and epithelial-mesenchymal transition. CONCLUSION: Our findings identify GaBL as a promising bioactive molecule with antitumor activity in vitro and support further studies to elucidate its molecular mechanisms and evaluate its therapeutic potential in vivo.