Development of New Strategy of Boron Neutron Capture Therapy to Cancer Combined with Tumor Specific Gene Delivery

我们进行了肿瘤特异性基因治疗增强BNCT效应的研究。(1)我们制备了一种包埋^ B化合物的聚乙二醇（PEG）结合脂质体<10>用于递送系统。在注射了μ <10>B-裸脂质体或μ <10>B-PEG-脂质体的小鼠的热中子照射后，相对于对照，AsPC-1肿瘤生长受到抑制。26号结肠肿瘤经转铁蛋白-β<10>-PEG-脂质体BNCT治疗后肿瘤消失。注射转铁蛋白-β<10>-PEG-脂质体和β<10>-B-PEG-脂质体在体内引起热中子照射的最大肿瘤抑制。(2)我们使用CR-39塑料径迹探测器进行中子俘获放射自显影（NCAR）。在立教大学、PSI、约瑟夫·斯特凡研究所或萨克利研究所，将与样品相连的CR-39探测器暴露于热中子或冷中子。PEG<10>-脂质体可以增加肿瘤组织中的B原子的蓄积，从而增加肿瘤组织中的B原子在血液中的滞留， 关于我们 降低并逃避RES的吞噬作用。(3)我们研制了一种新型的小型脉冲中子发生器。该中子发生器将应用于BNCT。(4)在肿瘤基因治疗中应用非病毒载体时，需要提高转染效率。我们制备了新型的质粒DNA-阳离子脂质复合物，称为四元复合物（“Qplex“），并评估了DNA递送效率。Qplex由阳离子脂质体、pDNA、鱼精蛋白和转铁蛋白组成。脂质体M-（α-三甲基氨乙酰基）-双十二烷基-D-脱乙酰基甜菜碱（TMAG）/二月桂酰磷脂酰胆碱（DLPC）/二油酰磷脂酰乙醇胺（DOPE）（1：2：2）。Xgal染色结果表明，Qplex可使lac Z基因的转染效率从常规阳离子脂质体的4%提高到52%。在血清存在下转染效率上级。(5)为了提高非病毒载体基因治疗的转染效率，在Lipoplex中评价了一种新的融合肽JTS-1。癌细胞系中的荧光素酶活性在使用JTS-1/LPD复合物中最大。Xgal染色显示转染效率高。LPD的平均直径为50 nm，与lipoplex（约600 nm）相比非常紧凑。用JTS-1/LPD复合物，在0.4μg/ml的tob DNA质粒作用下，AsPC-1细胞的肿瘤生长抑制率为50%。其抑制作用是通过诱导细胞凋亡而实现的。少

We performed the study of development of enhanced effects of BNCT with tumor specific gene therapy.(1) We prepare a polyethylene-glycol (PEG) binding liposome entrapped ^<10>B compound for the delivery system. After thermal neutron irradiation of mice injected with ^<10>B-bare liposome or ^<10>B-PEG-liposome, AsPC-1 tumour growth was suppressed relative to controls. Colon 26 tumor was disappeared by BNCT with the injection of Transferrin-^<10>B-PEG-Liposome. Injection of Transferrin-^<10>B-PEG-Liposome and ^<10>B-PEG-liposome caused the greatest tumour suppression with thermal neutron irradiation in vivo.(2) We performed neutron capture autoradiography(NCAR) using CR-39 plastic track detectors. The CR-39 detectors attached with samples were exposed to thermal neutrons or cold neutrons at Rikkyo University, PSI, Institute of Jozef Stefan or Sakley Institute. We can increase the accumulation of ^<10>B atoms in the tumor tissues by PEG-liposome, which increase the retension in the blood f … More low and escape the phagocytosis by RES.(3) We developed the novel small sized palsed neutron generator. This neutron generator will be applied to BNCT.(4) It is necessary to increase the transfectional efficiency when we use non-viral vector on cancer gene therapy. We have prepared new typed plasmid DNA-cationic lipoplexes, called quatenary complex (" Qplex "), and evaluated DNA delivery efficiency. Qplex is composed with cationic liposome, pDNA, protamine and transferrin. The lipid of liposome M-( α-trimethylammonioacetyl)-didodecyl-D-glutamatechloride (TMAG) / dilauroyl-phospatidylcholine (DLPC) / dioleoylphospatidyl-ethanolamine (DOPE) (1 : 2 : 2). The transfectional efficiency of lac Z gene is increased to 52% with Qplex from 4 % with conventional cationic lipoplexes in Xgal staining. The transfection efficiency is superior in the existence of serum.(5) In order to increase the transfection efficiency in non-viral vector gene therapy, a novel fusogenic peptide, JTS-1, was evaluated in Lipoplex. Luciferase activity in cancer cell lines was greatest in the using JTS-1/LPD complex. The high transfection effeciency was observed by Xgal staining. The mean diameter of LPD is 50 nm and it is so compact compared to lipoplex ( about 600nm ). Fifty percent tumor growth suppression of AsPC-1 cells was shown at the 0.4μg per ml of tob, "a novel tumor suppressor ", DNA plasmid using JTS-1/LPD complex. The suppressive effect was caused to induction of apoptosis. Less