TGFB2 Blockade Effects in Melanoma Cells

Abstract Objective: Transforming growth factor beta-2 (TGF-β2) is a member of TGF-β family of proteins regulating various aspects of carcinogenesis, including cancer cell proliferation, metabolism reprogramming, and microenvironment modification. Tumor microenvironment is often characterized by the presence of hypoxic areas that induces metabolic alterations in cancer cells. The aim of the study was to evaluate the efficacy of TGF-β2 blockade in B16, SK-MEL-2, and A375 melanoma cells in vitro under hypoxia as well as the antitumor activity of the TGF-β2 antisense oligonucleotides (ASO) in vivo. Material and Methods: TGF-β2 inhibition was performed by ASO transfection. The transfection efficacy was evaluated by expression analysis. Tumor growth dynamics, body weight, animal’s activity, and mass of internal organs were assessed. Results: Under hypoxic conditions (12–72 h), the expression of TGFB2 in B16 cells was increased, accompanied by the induction of HIF1A. Within 12–24 h of hypoxia exposure, B16 cells represented a fusiform shape, which can be a sign of acquiring the mesenchymal phenotype, whereas 72-h hypoxia led to the rounding of cells and loss of filopodia that can correspond to more cytotoxic effect. In vivo, monotherapy with ASO to TGF-β2 was associated with a tumor volume decrease by 2-fold as compared to negative control. Body weight, animal’s activity, and weights of internal organs did not differ between the groups studied. The results indicate that in vitro TGF-β2 inhibition effectively reduces gene expression that can be significant for better targeting of hypoxia-modified cancer cells.