Zeranol may increase the risk of leptin-induced neoplasia in human breast

Preparation of highly sensitive monoclonal antibody against α-zearalanol based on the similar antigen determinant structure to zearalanone

In this study, we report a new method to prepare highly sensitive monoclonal antibody against α-zearalanol (ZAL) based on a similar antigen determinant structure. Zearalanone (ZAN), structural analogs of ZAL, was modified by oximation to obtain ZAN-O. ZAN-O was then coupled with bovine serum albumin using 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide (EDC) to synthesise the artificial complete antigen ZAN-O-BSA. ZAN-O-BSA was used to immunise the BALB/c mice. The splenocytes of the immunised mice were fused with myeloma NS0 cells. During the process of cell fusion, ZAL was used as an inhibitor instead of ZAN to screen the hybridoma cell lines that can secrete monoclonal antibodies against ZAL. The sensitivity (half inhibitory concentration, IC50) of the prepared monoclonal antibody was 0.475 ng/ml, the limit of detection (LOD) was 0.050 ng/ml, the linear range of detection was 0.066-3.399 ng/ml, the affinity constant Kaff was 6.18×107 l/mol, the cross-reactivity rate with structural analogues, such as β-zearalanol, α-zearalenol, β-zearalenol, ZAN and zearalenone were 28.07, 13.16, 15.83, 60.28 and 7.95% respectively. The cross-reactivity with other mycotoxin and carrier proteins were all less than 0.05%. The prepared monoclonal antibody can be used to establish a highly sensitive immunoassay for the detection of ZAL.

Alterations in global DNA methylation and metabolism-related genes caused by zearalenone in MCF7 and MCF10F cells

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by Fusarium fungi. ZEN has endocrine disruptor effects and could impair the hormonal balance. Here, we aimed at investigating possible effects of ZEN on metabolism-related pathways and its relation to epigenetic mechanisms in breast adenocarcinoma (MCF7) and breast epithelial (MCF10F) cells. Using the MTT and neutral red uptake (NRU) cell viability tests, IC₅₀ values of ZEN after 24 h were found to be 191 μmol/L and 92.6 μmol/L in MCF7 cells and 67.4 μmol/L and 79.5 μmol/L in MCF10F cells. A significant increase on global levels of 5-methylcytosine (5-mC%) was observed for MCF7 cells, correlating with the increased expression of DNA methyltransferases. No alterations were observed on levels of 5-mC% and expression of DNA methyltransferases for MCF10F cells. Further, at least threefold upregulation compared to control was observed for several genes related to nuclear receptors and metabolism in MCF7 cells, while some of these genes were downregulated in MCF10F cells. The most notably altered genes were IGF1, HK2, PXR, and PPARγ. We suggested that ZEN could alter levels of global DNA methylation and impair metabolism-related pathways.