Bezerra Patrícia Heloise Alves, Ferreira Isadora Marques, Franceschi Beatriz Tinoco, Bianchini Francine, Ambrósio Luciana, Cintra Adélia Cristina O, Sampaio Suely Vilela, de Castro Fabíola Attié, Torqueti Maria Regina
Laboratory of Clinical Cytology, Department of Clinical Analyses, Toxicology and Food Science, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil.
Laboratory of Hematology, Department of Clinical Analyses, Toxicology and Food Science, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil.
J Venom Anim Toxins Incl Trop Dis. 2019 Jul 29;25:e20190010. doi: 10.1590/1678-9199-JVATITD-2019-0010. eCollection 2019.
Breast cancer is the neoplasm with both the highest incidence and mortality rate among women worldwide. Given the known snake venom cytotoxicity towards several tumor types, we evaluated the effects of BthTX-I from on MCF7, SKBR3, and MDAMB231 breast cancer cell lines.
BthTX-I cytotoxicity was determined via MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide assay. Cell death was measured by a hypotonic fluorescent solution method, annexin-V-FITC/propidium iodide staining and by apoptotic/autophagic protein expression. Cancer stem cells (CSCs) were quantified by flow cytometry using anti-CD24-FITC and anti-CD44-APC antibodies and propidium iodide.
BthTX-I at 102 µg/mL induced cell death in all cell lines. The toxin induced apoptosis in MCF7, SKBR3, and MDAMB231 in a dose-dependent manner, as confirmed by the increasing number of hypodiploid nuclei. Expression of pro-caspase 3, pro-caspase 8 and Beclin-1 proteins were increased, while the level of the antiapoptotic protein Bcl-2 was diminished in MCF7 cells. BthTX-I changed the staining pattern of CSCs in MDAMB231 cells by increasing expression of CD24 receptors, which mediated cell death.
BthTX-I induces apoptosis and autophagy in all breast cancer cell lines tested and also reduces CSCs subpopulation, which makes it a promising therapeutic alternative for breast cancer.
乳腺癌是全球女性中发病率和死亡率最高的肿瘤。鉴于已知蛇毒对多种肿瘤类型具有细胞毒性，我们评估了来自[具体来源未明确]的BthTX-I对MCF7、SKBR3和MDAMB231乳腺癌细胞系的影响。
通过MTT（3-(4,5-二甲基噻唑-2-基)-2,5-二苯基溴化四氮唑）法测定BthTX-I的细胞毒性。采用低渗荧光溶液法、膜联蛋白-V-异硫氰酸荧光素/碘化丙啶染色以及凋亡/自噬蛋白表达来检测细胞死亡情况。使用抗CD24-异硫氰酸荧光素和抗CD44-别藻蓝蛋白抗体以及碘化丙啶，通过流式细胞术对癌症干细胞（CSCs）进行定量分析。
102μg/mL的BthTX-I在所有细胞系中均诱导细胞死亡。如通过亚二倍体核数量增加所证实，该毒素以剂量依赖方式诱导MCF7、SKBR3和MDAMB231细胞凋亡。在MCF7细胞中，前半胱天冬酶3、前半胱天冬酶8和Beclin-1蛋白的表达增加，而抗凋亡蛋白Bcl-2的水平降低。BthTX-I通过增加介导细胞死亡的CD24受体的表达，改变了MDAMB231细胞中CSCs的染色模式。
BthTX-I在所有测试的乳腺癌细胞系中均诱导凋亡和自噬，并且还减少了CSCs亚群，这使其成为乳腺癌一种有前景的治疗选择。
