Wei Y Q, Zhao X, Kariya Y, Teshigawara K, Uchida A
Department of Late Effect Studies, Kyoto University, Japan.
Cancer Immunol Immunother. 1995 Feb;40(2):73-8. doi: 10.1007/BF01520287.
Tumor cells often express elevated levels of heat-shock protein (HSP) 70. The present study was designed to investigate the role of HSP70 in the proliferation and survival of tumor cells in the human system. When Molt-4 and other tumor cells were treated in vitro with HSP70 antisense oligomer, they displayed propidium-iodide-stained condensed nuclei (intact or fragmented). A ladder-like pattern of DNA fragments was observed with HSP70 antisense-oligomer-treated tumor cells in agrose gel electrophoresis, which was consistent with internucleosomal DNA fragmentation. Flow cytometry analysis revealed the hypodiploid DNA peak of propidium-iodide-stained nuclei in the antisense-oligomer-treated cells. The apoptosis induced by HSP antisense oligomer was dose- and time-dependent. The antisense oligomer induced apoptosis mainly in tumor cells at G1 and S phase, resulting in an inhibition of cell proliferation. HSP70 antisense oligomer caused DNA-sequence-specific inhibition of HSP70 expression, which preceded apparent apoptosis. These results indicate that HSP70 antisense treatment inhibits the expression of HSP70, which in turn inhibits cell proliferation and induces apoptosis in tumor cells and suggest that HSP70 is required for tumor cells to proliferate and survive under normal condition.
肿瘤细胞常常表达高水平的热休克蛋白（HSP）70。本研究旨在探讨HSP70在人体系统中肿瘤细胞增殖和存活过程中的作用。当用HSP70反义寡聚体体外处理Molt-4细胞和其他肿瘤细胞时，它们呈现出碘化丙啶染色的凝聚细胞核（完整或碎片化）。在琼脂糖凝胶电泳中，用HSP70反义寡聚体处理的肿瘤细胞观察到了DNA片段的梯状模式，这与核小体间DNA片段化一致。流式细胞术分析显示，在反义寡聚体处理的细胞中，碘化丙啶染色的细胞核出现亚二倍体DNA峰。HSP反义寡聚体诱导的凋亡呈剂量和时间依赖性。反义寡聚体主要在处于G1期和S期的肿瘤细胞中诱导凋亡，从而抑制细胞增殖。HSP70反义寡聚体导致HSP70表达的DNA序列特异性抑制，这先于明显的凋亡发生。这些结果表明，HSP70反义处理抑制了HSP70的表达，进而抑制了肿瘤细胞的增殖并诱导其凋亡，提示HSP70是肿瘤细胞在正常条件下增殖和存活所必需的。
