Experimental research for the availability of gene therapy using ORP150, a novel molecular chaperone

新合成的蛋白质和未成熟的蛋白质由于形成疏水区而容易聚集。许多应激条件，如热休克或缺氧，减缓了它们的折叠过程，并导致细胞中未折叠/错误折叠蛋白质的积累。分子伴侣，包括热休克蛋白（iisp），在这些条件下被诱导，与未折叠/错误折叠的蛋白质结合，并帮助它们正确折叠或再折叠。分子伴侣对应激细胞的保护作用已有报道。血管生成因子如血管内皮生长因子（VEGF）在细胞应激条件下的表达涉及转录和翻译事件，以及诱导内质网（ER）伴侣的重要作用。VEGF和150- kdaoxo -regulated protein (ORP)（一种新型内质网伴侣）在人胶质母细胞瘤中的共表达表明血管生成与ORP150之间存在联系。ORP150反义转染后，C6胶质瘤细胞的ORP150表达有选择性地降低。用ORP150反义C6胶质瘤转染物培养免疫受损小鼠后，肿瘤表现出与野生型C6胶质瘤细胞相当的初始生长阶段，随后在8天内显着消退。与过度表达ORP150或载体对照的C6细胞衍生的肿瘤相比，肿瘤床内血小板/内皮细胞粘附分子1阳性结构密度降低与表达ORP150反义的C6胶质瘤血管生成减少一致。在体外，抑制ORP150表达可减少VEGF在培养上清液中的释放；在ORP150反义转染中，VEGF在内质网内的细胞内积累。这些发现表明，可诱导的内质网伴侣ORP150在肿瘤介导的血管生成过程中通过VEGF的加工发挥了关键作用，因此，强调了肿瘤治疗操作血管生成机制的新方面。热休克蛋白(HSPs)/应激蛋白是受各种环境和生理刺激诱导的分子伴侣。热休克蛋白的表达与细胞生长或转化的调节之间的关系的证据已经积累。150 kda氧调节蛋白（ORP150）是lisp家族的新成员，在内质网中起分子伴侣的作用。我们研究了转导的反义ORP150 cDNA是否能降低致瘤性和血管生成性。本文描述了这些应激蛋白与癌症的关系以及抗癌基因治疗的可能性。少

Newly synthesized protein and immature proteins are easily aggregated because they ej(pose hydrophobic regions. Many stress conditions, such as heat shock or hypoxia, slow down their folding process and cause accumulation of unfolded/misfolded proteins in the cell. Molecular chaperones, including heat shock'proteins (IISPs), are induced in these conditions, bind to unfolded/misfolded proteins, and help them to be folded or reflolded properly. The protective role of molecular chaperones for the cells under stress has been reported.Expression of angiogenic factors such as vascular endothelial growth factor (VEGF) under conditions of cell stress involves both transcriptionaland translational events, as well as an important role for inducible endoplasmicreticulum (ER) chaperones. Coexpression of VEGF and 150-kDaoxygen-regulated protein (ORP), a novel ER chaperone, in human glioblastomasuggested a link between angiogenesis and ORP150. C6 gliomacells stably transfected with ORP150 antisense … More displayed selectively reduced ORP150 expression. Tumors raised after in culation of immunocompromisedmice with ORP150 antisense C6 glioma transfectants demonstratedan initial phase of growth comparable to wild-type C6 gliomacells which was followed by marked regression within 8 days. Decreaseddensity of platelet/endothelial cell adhesion molecule 1-positive structureswithin the tumor bed was consistent with reduced angiogenesis in C6 gliomas expressing ORP150 antisense, compared with tumors derived from C6 cells overexpressing ORP150 sense or vector controls. In vitro,inhibition of ORP150 expression decreased release of VEGF into culturesupernatants ; in ORP150 antisense transfectants, VEGF accumulatedintracellularly within the ER. These findings demonstrate a critical rolefor the inducible ER chaperone ORP150 in tumor-mediated angiogenesisvia processing of VEGF, and, thus, highlight a new facet of angiogenicmechanisms amenable to therapeutic manipulation in tumors.Heat shock proteins (HSPs)/stress proteins are molecular chaperflnes that are induced by various environmental and physiological stimuli. Evidence of the relations between the expression of HSPs and the regulation of cell growth or transformation has accumulated. The 150-kDa oxygen-regulated protein (ORP150), a new member of lisp family, functions as a molecular chaperone in the endoplasmic reticulum. We have examined whether transduced antisense ORP150 cDNA reduces tumorigenicity and angiogenicity. Relations between these stress proteins and cancer and possibilities for anticancer gene therapy are described. Less