Department of Biology, University of Rome Tor Vergata, Via della Ricerca Scientifica, 00133, Rome, Italy.
J Cell Mol Med. 2010 Mar;14(3):564-77. doi: 10.1111/j.1582-4934.2008.00588.x. Epub 2008 Nov 14.
Garlic organosulphur compounds have been successfully used as redox anti-proliferative agents. In this work, we dissect the effects of diallyl disulphide (DADS) focusing on the events upstream of cell cycle arrest and apoptosis induced in neuroblastoma SH-SY5Y cells. We demonstrate that DADS is able to cause early morphological changes, cytoskeleton oxidation, microfilaments reduction and depolymerization of microtubules. These events are attenuated in cells stably overexpressing the antioxidant enzyme SOD1, suggesting that superoxide plays a crucial role in destabilizing cytoskeleton. Moreover, we evidence that the main microtubules-associated protein Tau undergoes PP1-mediated dephosphorylation as demonstrated by treatment with okadaic acid as well as by immunoreaction with anti-Tau-1 antibody, which specifically recognizes its dephosphorylated forms. Tau dephosphorylation is inhibited by the two-electron reductants NAC and GSH ester but not by SOD1. The inability of DADS to induce apoptosis in neuroblastoma-differentiated cells gives emphasis to the anti-proliferative activity of DADS, which can be regarded as a promising potent anti-neuroblastoma drug by virtue of its widespread cytoskeleton disrupting action on proliferating cells.
大蒜有机硫化合物已成功用作氧化还原抗增殖剂。在这项工作中，我们剖析了二烯丙基二硫（DADS）的作用，重点研究了其在诱导神经母细胞瘤 SH-SY5Y 细胞周期停滞和细胞凋亡过程中上游事件。我们证明 DADS 能够引起早期形态变化、细胞骨架氧化、微丝减少和微管解聚。在稳定过表达抗氧化酶 SOD1 的细胞中，这些事件被减弱，这表明超氧阴离子在破坏细胞骨架方面起着至关重要的作用。此外，我们证明主要的微管相关蛋白 Tau 经历了蛋白磷酸酶 1（PP1）介导的去磷酸化，这一点通过用渥曼青霉素处理以及用抗 Tau-1 抗体进行免疫反应得到证实，抗 Tau-1 抗体特异性识别其去磷酸化形式。Tau 的去磷酸化被二电子还原剂 NAC 和 GSH 酯抑制，但不受 SOD1 抑制。DADS 不能在神经母细胞瘤分化细胞中诱导细胞凋亡，这强调了 DADS 的抗增殖活性，由于其对增殖细胞广泛的细胞骨架破坏作用，DADS 可被视为一种有前途的强效抗神经母细胞瘤药物。
