Department of Clinical Pharmacology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192‑0392, Japan.
Department of Applied Biochemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan.
Int J Oncol. 2018 Jun;52(6):1959-1971. doi: 10.3892/ijo.2018.4357. Epub 2018 Apr 4.
In China, arsenic disulfide (As2S2) has been used for the treatment of hematological malignancies. The present study aimed to evaluate the effects of As2S2 on the human breast cancer MCF‑7 cell line cultured in both two‑dimensional (2D) monolayers and three‑dimensional (3D) spheroids to explore its therapeutic potential in breast cancer treatment. Cellular viability and the induction of apoptosis were examined with a cell counting kit‑8 (CCK‑8) assay and flow cytometric analysis, respectively. Alterations in the expression levels of apoptosis‑associated proteins, including Bcl‑2‑associated X protein (Bax), B‑cell lymphoma 2 (Bcl‑2), p53, and caspase‑7, as well as the cell survival‑associated proteins, phosphatidylinositol 3‑kinase (PI3K), Akt, and mammalian target of rapamycin (mTOR), were assessed by western blotting. Although a dose‑dependent reduction in cell viability, which occurred in association with the induction of apoptosis triggered by the addition of 2‑24 µM As2S2, was observed in both 2D‑ and 3D‑culture systems, 3D spheroids were less sensitive to the cytotoxic effect of As2S2 compared with the 2D cultured cells. A significant increase in the expression levels of Bax, p53, and caspase‑7 was observed in treated 2D‑cultured cells, whereas a similar increase in the expression levels of Bax was only confirmed in treated 3D spheroids, although there was a trend towards the increased expression of p53 and caspase‑7 in the 3D spheroids. These results suggested that these molecules are closely associated with As2S2‑mediated cytotoxicity in the two culture systems, and further suggested that the difference in the sensitivity to As2S2 between 2D monolayers and 3D spheroids may be attributed to the differential alterations in the expression levels of proteins associated with cell mortality. Significant downregulation of the expression levels of Bcl‑2, PI3K, Akt and mTOR was observed in the two culture systems. Taken together, the results of the present study demonstrated that As2S2 inhibits cell viability and induces apoptosis in both 2D‑ and 3D‑ cultured MCF‑7 cells, which may be associated with activation of the pro‑apoptotic pathway and the inhibition of pro‑survival signaling. These results have provided novel insights into clinical applications of As2S2 in the treatment of patients with breast cancer.
在中国，二硫化二砷 (As2S2) 已被用于治疗血液系统恶性肿瘤。本研究旨在评估 As2S2 对二维 (2D) 单层和三维 (3D) 球体培养的人乳腺癌 MCF-7 细胞系的影响，以探索其在乳腺癌治疗中的治疗潜力。通过细胞计数试剂盒-8 (CCK-8) 测定和流式细胞术分析分别检测细胞活力和凋亡诱导。通过蛋白质印迹法评估凋亡相关蛋白（包括 Bcl-2 相关 X 蛋白 (Bax)、B 细胞淋巴瘤 2 (Bcl-2)、p53 和半胱天冬酶-7）以及细胞存活相关蛋白（磷脂酰肌醇 3-激酶 (PI3K)、Akt 和哺乳动物雷帕霉素靶蛋白 (mTOR)）的表达水平。尽管在 2D 和 3D 培养系统中均观察到 2-24 μM As2S2 加入后细胞活力呈剂量依赖性降低，与凋亡诱导有关，但 3D 球体对 As2S2 的细胞毒性作用的敏感性低于 2D 培养细胞。在 2D 培养的细胞中，Bax、p53 和半胱天冬酶-7 的表达水平显著增加，而在处理的 3D 球体中仅证实了 Bax 表达水平的类似增加，尽管 3D 球体中 p53 和半胱天冬酶-7 的表达水平有增加的趋势。这些结果表明，这些分子与两种培养系统中 As2S2 介导的细胞毒性密切相关，并且进一步表明 2D 单层和 3D 球体之间对 As2S2 敏感性的差异可能归因于与细胞死亡率相关的蛋白表达水平的差异变化。在两种培养系统中均观察到 Bcl-2、PI3K、Akt 和 mTOR 的表达水平显著下调。总之，本研究的结果表明，As2S2 抑制 2D 和 3D 培养的 MCF-7 细胞的细胞活力并诱导细胞凋亡，这可能与促凋亡途径的激活和抗生存信号的抑制有关。这些结果为 As2S2 在治疗乳腺癌患者中的临床应用提供了新的见解。
