Binary or Bin toxin produced by Lysinibacillus sphaericus is composed of BinA (42 kDa) and BinB (51 kDa) subunits. These work together to exert maximal toxicity against mosquito larvae via pore formation and induction of apoptosis. The C-terminal domains in both subunits are homologous to those of aerolysin-type β pore-forming toxins, including parasporin-2 (PS2). The latter is one of the Bacillus thuringiensis toxins that exhibits specific cytotoxicity against human cancer cells. The present study investigates the possible anticancer activity of Bin toxin using PS2 as a control. We demonstrate that treatment with a high concentration of trypsin-activated Bin inhibits cell proliferation in human cancer cells A549, Caco-2, HepG2, HK-1 and KKU-M055. In the most susceptible cells, HK-1, Bin toxin exposure led to morphological alterations, decreased migration, decreased adhesion activity and apoptosis induction. Although these effects necessitated high concentrations, they suggest that Bin toxin may be optimized as a novel potential cancer-therapeutic agent.

由球形赖氨酸杆菌产生的二元或 Bin 毒素由 BinA (42 kDa) 和 BinB (51 kDa) 亚基组成。这些共同作用通过孔形成和诱导细胞凋亡对蚊子幼虫发挥最大毒性。两个亚基中的 C 端结构域与气溶素型 β 成孔毒素的结构域同源，包括 parasporin-2 (PS2)。后者是苏云金芽孢杆菌中的一种对人类癌细胞表现出特定细胞毒性的毒素。本研究使用 PS2 作为对照研究了 Bin 毒素可能的抗癌活性。我们证明用高浓度胰蛋白酶激活的 Bin 处理可抑制人类癌细胞 A549、Caco-2、HepG2、HK-1 和 KKU-M055 的细胞增殖。在最易感的细胞 HK-1 中，Bin 毒素暴露导致形态改变、迁移减少、粘附活性降低和细胞凋亡诱导。尽管这些影响需要高浓度，但它们表明 Bin 毒素可以优化为一种新型的潜在癌症治疗剂。