Immunohistochemistry for assessing toxicity and mechanism of action of anticancer drugs during preclinical trials. From theory to practice

Aim. To identify the most suitable pathogenetic mechanisms for in-depth study of the antitumor and antimetastatic effects of tested hybrid organotin compounds using the immunohistochemical approach. Materials and Methods . Here, we tested bis(3,5-di-tert-butyl-4-hydroxyphenylthiolate) dimethyltin (laboratory code Me-3), belonging to the class of hybrid organotin compounds, on 30 female C57Bl/6 mice using a universal model of transplantable tumors with spontaneous metastasis (B16 melanoma). 48 hours after tumor cell transplantation, we intraperitoneally administered Me-3 once daily to female C57Bl/6 mice for 10 days at a total dose (TD) of 375 mg/kg. For histological analysis, we used the primary tumor node of B16 melanoma. Immunophenotyping of B16 melanoma tissue samples was carried out using the polyclonal antibodies to transforming growth factor beta 1 (TGFβ-1), vascular endothelial growth factor A (VEGFA), Bcl2-associated X Protein (Bcl-2), cluster of differentiation 34 (CD34). Results . After the exposure to Me-3, we found a reduced immunohistochemical signal to TGF-β1 and Bcl-2 3 in the tumor tissue. Low doses of Me-3 have also impacted angiogenesis. Conclusion. Me-3 has a pro-apoptotic and anti-angiogenetic effects on B16 melanoma cells in C57Bl/6 mice.