Fumonisin B 1-induced apoptosis in neuroblastoma, glioblastoma and hypothalamic cell lines

Abstract

Fumonisin B 1 (FB 1) is a mycotoxin produced by Fusarium verticilliodes, which commonly infects corn across the world. Fusarium fungi may also be found in moisture-damaged buildings. In this study, we investigated the role of apoptosis in the toxicity of FB 1 in four different cell lines. Activation of caspase-3-like protease, DNA fragmentation and expression of p53 and Bcl-2 family proteins were studied in mouse GT1-7 hypothalamic, rat C6 glioblastoma, human U-118MG glioblastoma, and human SH-SY5Y neuroblastoma cells exposed to 0.1–100 μM FB 1 for 0–144 h. Caspase-3-like protease activity increased in all cell lines, except SH-SY5Y, at 48–144 h, and internucleosomal DNA fragmentation occurred in all of the cell lines, pointing to a role for apoptosis in the toxicity of FB 1. However, the expressions of p53 or pro- or antiapoptotic Bcl-2 family proteins (Bax, Bcl-2, Bcl-X L and Mcl-1) were not affected in any of the cell lines even after prolonged exposure to FB 1 at high doses. The results of this study, together with the results of our previous studies, provide evidence that FB 1 is a potential neurotoxin, but that the toxicity of FB 1 varies between different cell lines. The sensitivity of these cell lines towards FB 1 is as follows: U-118MG > GT1-7 > C6 > SH-SY5Y cells. These results are consistent with the assumption that cells of glial origin may be more sensitive towards FB 1 than cells of neural origin.