Development of new antitumor drugs and apoptotic signal transudation - Application to feline leukemia and canine lymphoma -

在临床上，实体瘤细胞与抗癌药物和放射的组合治疗被广泛用于增强细胞杀伤。1-（3-C-Ethynyl-β-D-ribo-pentofuranosyl）cytosine（ECyd）和2-chrolo-deoxyadenosine（Cl-Ade）是新近开发的通过抑制RNA合成诱导细胞死亡的抗癌药物。在这项研究中，我们研究了这些抗癌药物或/和电离辐射暴露于人胃腺癌MKN 45细胞，人白血病细胞系MOLT-4细胞和犬淋巴瘤细胞系CL-1是否诱导凋亡。在MOLT-4细胞中，Cl-Ade处理后观察到Fas表达和caspase 8/3激活的凋亡细胞死亡，随后观察到凋亡细胞死亡。2Cl-Ade和ECyd可诱导犬淋巴瘤细胞CL-1凋亡。照射前用0.1 μM ECyd处理MKN 45细胞1 h。20戈伊照射后，荧光显微镜下观察凋亡细胞和肿胀细胞 ...更多信息 结合碘化丙啶染色或电子显微镜检查，并进行评分。当细胞单独用ECyd处理时，仅出现5%的凋亡或坏死细胞。当细胞单独暴露于X射线时，出现约5%的凋亡和约45%的肿胀细胞。然而，当细胞在0.1 μM ECyd存在下暴露于X射线时，约25%的总细胞为凋亡细胞，约10%的总细胞为肿胀细胞。Ac-DEVD-CHO（caspase 3抑制剂）和TPCK（糜蛋白酶样蛋白酶抑制剂）可明显抑制ECyd和X射线联合诱导的细胞凋亡，提示caspase 3和糜蛋白酶样蛋白酶参与了ECyd和X射线联合诱导的细胞凋亡。在这项研究中，它被证明，共同处理的MKN 45细胞与ECyd和X射线激活G2期相关的凋亡信号与caspase 3和糜蛋白酶样蛋白酶。这些数据可能为开发放射联合抗癌药物治疗实体瘤的临床治疗提供有用的信息。少

Clinically, the combination treatment of solid tumor cells with an anticancer drug and radiation was widely used to enhance cell killing. 1-(3-C-Ethynyl-β-D-ribo-pentofuranosyl) cytosine (ECyd) and 2-chrolo-deoxyadenosine (Cl-Ade) was newly developed as anticancer drugs to induce cell death by inhibiting RNA synthesis. In this study, we examined whether the exposure of these anticancer drugs or /and ionizing radiation to human gastric adenocarcinoma MKN45 cells, human lekemia cell line MOLT-4 cells induce apoptosis and canine lymphoma cell line CL-1. In MOLT-4 cells, Fas expression and caspase 8/3 activation apoptotic cell death was observed after treatment of Cl-Ade, followed by apoptotic cell death. 2Cl-Ade and ECyd showed to induce apoptotic cell death in canine lymphoma cell CL-1 cells. MKN45 cells were treated with 0.1 μM ECyd for 1 h before irradiation. After irradiation with 20 Gy, apoptotic as well as swelling cells were morphologically discriminated by fluorescence microscopy … More combined with propidium iodide staining or electron microscopy and were scored. When cells were treated with ECyd alone, only 5 % of either apoptotic or necrotic cells appeared. When cells were exposed to X rays alone, about 5 % of apoptotic and about 45 % of swelling cells appeared. However, when cells were exposed to X rays in the presence of 0.1 μM ECyd, about 25 % of total cells was apoptotic cells and about 10 % of total cells was swelling cells. Apoptosis induced by treating cells with ECyd and X irradiation was significantly reduced by the treatment with Ac-DEVD-CHO (caspase 3 inhibitor) or TPCK (chymotrypsin-like protease inhibitor).These results suggested that caspase 3 and chymotrypsin-like proteases were responsible for apoptosis induced by co-treatment with ECyd and X rays. In this study, it was demonstrated that co-treatment of MKN45 cells with ECyd and X rays activated G2-phase-linked apoptotic signaling associated with caspase 3 and chymotrypsin like protease. These data may provide useful information to develop clinical treatment of radiation combined with anticancer drugs for solid tumors. Less