Ohara Tadashi, Morishita Tetsuo, Suzuki Hidekazu, Masaoka Tatsuhiro, Ishii Hiromasa, Hibi Toshifumi
Department of Internal Medicine, Tokyo Dental College, Chiba Hospital, Chiba 261-8502, Japan.
Anticancer Res. 2004 Nov-Dec;24(6):3723-30.
The effects of bacterial eradication therapy cannot be fully explained simply by elimination of the target bacteria, if one considers the effects of eradication therapy in H. pylori-negative cases of low-grade malignancy MALTomas of the rectum. The present study was undertaken to examine the possibility and mechanism of direct induction of apoptosis of the tumor cells by the antibiotics used for bacterial eradication therapy.
A B cell lymphoma cell line (300-19) derived from BALB/c mice was co-cultured with amoxicillin or clarithromycin, and amoxicillin and clarithromycin at concentrations equal to or 1/10 x MIC of either drug. Cells co-cultured with 1/100 x MIC of the standard anti-tumor agents, adriamycin, vincristine and cyclophosphamide, served as positive controls. Cells cultured without any antibiotic or anti-tumor agent served as controls. In each group, the following analyses were performed: (i) the time-course of changes in the cellular morphology, (ii) the time-course of occurrence of DNA fragmentation, (iii) the appearance of apoptotic changes as evaluated by trypan blue staining, (iv) Bcl-2 expression as examined by immunoblotting; and (v) the expression of TNFR1, Fas, FasL and caspase-3, -8 and -9, as evaluated by immunoblotting.
Cells treated with amoxicillin and clarithromycin showed the formation of apoptotic bodies, and degeneration and detachment of the cells in a dose-dependent manner. DNA fragmentation was induced in these cells to a degree similar to that seen in cells treated with the anti-tumor agents. Trypan blue staining also demonstrated apoptosis of the cells and loss of cell viability. Bcl-2 expression was seen only in the control group and FasL was never seen, while the expression of TNFR1, Fas and caspase-3, -8 and -9 was seen in the amoxicillin-treated group, clarithromycin-treated group, amoxicillin and clarithromycin-treated group and the positive control group.
Antibiotics used for the eradication of H. pylori can also directly induce apoptosis in mouse B cell lymphoma cells, an action which involves the TNF system.
如果考虑根除治疗对直肠低级别恶性黏膜相关淋巴组织淋巴瘤（MALToma）中幽门螺杆菌阴性病例的影响，单纯通过消除目标细菌并不能完全解释细菌根除治疗的效果。本研究旨在探讨用于细菌根除治疗的抗生素直接诱导肿瘤细胞凋亡的可能性及其机制。
将源自BALB/c小鼠的B细胞淋巴瘤细胞系（300-19）与阿莫西林或克拉霉素，以及浓度等于或为任一药物最低抑菌浓度（MIC）1/10的阿莫西林和克拉霉素共同培养。与浓度为标准抗肿瘤药物阿霉素、长春新碱和环磷酰胺1/100 MIC共同培养的细胞作为阳性对照。未用任何抗生素或抗肿瘤药物培养的细胞作为对照。在每组中进行以下分析：（i）细胞形态变化的时间进程；（ii）DNA片段化发生的时间进程；（iii）通过台盼蓝染色评估凋亡变化的出现情况；（iv）通过免疫印迹检测Bcl-2表达；以及（v）通过免疫印迹评估肿瘤坏死因子受体1（TNFR1）、Fas、Fas配体（FasL）和半胱天冬酶-3、-8和-9的表达。
用阿莫西林和克拉霉素处理的细胞呈现凋亡小体形成以及细胞的变性和脱离，且呈剂量依赖性。这些细胞中诱导的DNA片段化程度与用抗肿瘤药物处理的细胞相似。台盼蓝染色也显示细胞凋亡和细胞活力丧失。仅在对照组中观察到Bcl-2表达，从未观察到FasL表达，而在阿莫西林处理组、克拉霉素处理组、阿莫西林和克拉霉素处理组以及阳性对照组中观察到TNFR1、Fas和半胱天冬酶-3、-8和-9的表达。
用于根除幽门螺杆菌的抗生素也可直接诱导小鼠B细胞淋巴瘤细胞凋亡，这一作用涉及肿瘤坏死因子系统。
