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

我们开展了BNCT与肿瘤特异性基因治疗相结合的增强效应的研究。(1)制备了聚乙二醇结合脂质体，用于给药系统。经热中子照射后，注射裸露脂质体或脂质体的小鼠ASPC-1肿瘤生长受到抑制。BNCT注射转铁蛋白-10-GT；B-聚乙二醇脂质体可使26例结肠癌肿瘤消失。体内注射转铁蛋白-10&gt；B-聚乙二醇-脂质体和转铁蛋白-10-聚乙二醇-脂质体对热中子照射的肿瘤抑制作用最强。(2)用CR-39塑料径迹探测器进行了中子捕获放射自显影(NCAR)。与样品连接的CR-39探测器在Rikkyo大学、PSI、Jozef Stefan研究所或Sakley研究所暴露于热中子或冷中子。聚乙二醇脂质体可以增加肿瘤组织中~(10)B原子的蓄积，从而增加血中…的滞留量。更低，逃脱了RES的吞噬作用。(3)研制了一种新型的小型掌状中子发生器。该中子发生器将应用于BNCT。(4)在肿瘤基因治疗中使用非病毒载体时，有必要提高转染率。我们制备了一种新型的DNA-阳离子脂复合体，称为四链复合体(Qplex)，并对DNA的传递效率进行了评价。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-trimethylammonioacetyl)-didodecyl-D-glutamatechloride)/二月桂酰磷脂酰胆碱(DLPC)/二油酰磷脂酰乙醇胺(DOPE)(1：2：2)；用Qplex将lac Z基因的转染率从常规阳离子脂质体的4%提高到52%。为了提高非病毒载体基因治疗中的转染率，在Lipoplex中对一种新的融合多肽JTS-1进行了鉴定。在使用JTS-1/LPD复合体的癌细胞中，荧光素酶活性最高。X-Gal染色观察到高转染率。LPD的平均直径为50 nm，与Lipoplex(约600 nm)相比，LPD非常致密。用JTS-1/LPD复合体构建的新型抑癌基因TOB的浓度为0.4μg/ml时，对Aspc-1细胞的生长抑制率为50%。抑制作用是通过诱导细胞凋亡来实现的。较少

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