Publications -- J. Michael Mathis

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12503/31834

This collection is limited to articles published under the terms of a creative commons license or other open access publishing agreement since 2016. It is not intended as a complete list of the author's works.

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    Mechanistic studies of cytotoxic activity of the mesoionic compound MIH 2.4Bl in MCF-7 breast cancer cells
    (Spandidos Publications, 2020-06-19) Amaral de Mascena Costa, Luciana; Debnath, Dipti; Harmon, Ashlyn C.; de Sousa Araujo, Silvany; Diogenes da Silva Souza, Helivaldo; Filgueiras de Athayde Filho, Petronio; Wischral, Aurea; Adriao Gomes Filho, Manoel; Mathis, J. Michael
    In the present study, the cytotoxic effects of a 1,3-thiazolium-5-thiolate derivative of a mesoionic compound, MIH 2.4Bl, were assessed in the MCF-7 breast cancer cell line. The cytotoxic effects of MIH 2.4Bl were determined using a crystal violet assay. Using a dose-response curve, the IC50 value of MIH 2.4Bl was determined to be 45.8+/-0.8 microM. Additionally, the effects of MIH 2.4Bl on mitochondrial respiration were characterized using oxygen consumption rate analysis. Treating MCF-7 cells with increasing concentrations of MIH 2.4Bl resulted in a significant reduction in all mitochondrial respiratory parameters compared with the control cells, indicative of an overall decrease in mitochondrial membrane potential. The induction of autophagy by MIH 2.4Bl was also examined by measuring changes in the expression of protein markers of autophagy. As shown by western blot analysis, treatment of MCF-7 cells with MIH 2.4Bl resulted in increased protein expression levels of Beclin-1 and ATG5, as well as an increase in the microtubule-associated protein 1A/1B light chain 3B (LC3B)-II to LC3B-I ratio compared with the control cells. Microarray analysis of changes in gene expression following MIH 2.4Bl treatment demonstrated 3,659 genes exhibited a fold-change >/=2. Among these genes, 779 were up-regulated, and 2,880 were down-regulated in cells treated with MIH 2.4Bl compared with the control cells. Based on the identity of the transcripts and fold-change of expression, six genes were selected for verification by reverse transcription-quantitative (RT-q)PCR; activating transcription factor 3, acidic repeat-containing protein, heparin-binding EGF-like growth factor, regulator of G-protein signaling 2, Dickkopf WNT signaling pathway inhibitor 1 and adhesion molecule with Ig like domain 2. The results of RT-qPCR analysis of RNA isolated from control and MIH 2.4Bl treated cells were consistent with the expression changes identified by microarray analysis. Together, these results suggest that MIH 2.4Bl may be a promising candidate for treating breast cancer and warrants further in vitro and in vivo investigation.
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    Cytotoxic Activity of the Mesoionic Compound MIH 2.4Bl in Breast Cancer Cell Lines
    (Sage Publications, 2020-07-01) Amaral de Mascena Costa, Luciana; Harmon, Ashlyn C.; Aguiar Coelho Teixeira, Alvaro; Cassio Silva de Lima, Filipe; de Sousa Araujo, Silvany; Del Piero, Fabio; Diogenes da Silva Souza, Helivaldo; Filgueiras de Athayde Filho, Petronio; Alves Junior, Severino; de Mascena Diniz Maia, Maria; Wischral, Aurea; Adriao Gomes Filho, Manoel; Mathis, J. Michael
    In this work, we report the synthesis of a new 1,3-thiazolium-5-thiolate derivative of a mesoionic compound (MIH 2.4Bl) and the characterization of its selective cytotoxicity on a panel of breast cancer cells lines. The cytotoxic effect of MIH 2.4Bl on breast cancer cell lines was determined by XTT and crystal violet assays, flow cytometry analysis, electron microscopy characterization, and terminal deoxynucleotidyl transferase (TdT) deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL) apoptosis assays. As determined using XTT cell growth and survival assays, MIH 2.4Bl exhibited growth inhibition activity on most breast cancer cell lines tested, compared with normal human mammary epithelial cells. Three breast cancer cell lines (MCF-7, T-47D, and ZR-75-1) showed a more potent sensitivity index to growth inhibition by MIH 2.4Bl than the other breast cancer cell lines. Interestingly, these 3 cell lines were derived from tumors of Luminal A origin and have ER (estrogen receptor), PR (progesterone receptor), and HER2 (human epidermal growth factor receptor 2) positive expression. Additional analysis of cytotoxicity mediated by MIH 2.4Bl was performed using the MCF-7 cell line. MCF-7 cells displayed both time- and dose-dependent decreases in cell growth and survival, with a maximum cytotoxic effect observed at 72 and 96 hours. The MCF-7 cells were also characterized for cell cycle changes upon treatment with MIH 2.4Bl. Using flow cytometry analysis of cell cycle distribution, a treatment-dependent effect was observed; treatment of cells with MIH 2.4Bl increased the G2/M population to 34.2% compared with 0.1% in untreated (control) cells. Ultrastructural analysis of MFC-7 cells treated with MIH 2.4Bl at 2 different concentrations (37.5 and 75 muM) was performed by transmission electron microscopy. Cells treated with 37.5 muM MIH 2.4Bl showed morphologic changes beginning at 6 hours after treatment, while cells treated with 75 muM showed changes beginning at 3 hours after treatment. These changes were characterized by an alteration of nuclear morphology and mitochondrial degeneration consistent with apoptotic cell death. Results of a TUNEL assay performed on cells treated for 96 hours with MIH 2.4Bl supported the observation of apoptosis. Together, these results suggest that MIH 2.4Bl is a promising candidate for treating breast cancer and support further in vitro and in vivo investigation.