Zhang R, Minemura K, De Groot L J
Department of Medicine, University of Chicago, Illinois 60637, USA.
Endocrinology. 1998 Feb;139(2):601-8. doi: 10.1210/endo.139.2.5764.
We have evaluated the feasibility of gene transduction using replication-defective adenovirus vector as a novel therapy for medullary thyroid carcinoma (MTC), a thyroid C cell neoplasm. Replication-defective adenoviruses were constructed to express murine interleukin-2 (mIL-2) gene and Escherichia coli beta-galactosidase (beta-gal; lacZ) gene under the control of the human cytomegalovirus (CMV) promoter (AdCMVmIL2, AdCMVbeta-gal) by homologous recombination. The efficiency of transduction was evaluated using AdCMVbeta-gal at different conditions. The gene transduction efficiency was dependent on multiplicity of infection, duration of exposure to the virus, and viral concentration. The expression of functional mIL-2 in transduced tumor cells was verified both in vitro and in vivo. Two cell lines (rat MTC and mMTC) secreted large amounts of functional mIL-2 after transduction, as tested in cytotoxic T lymphocyte (CTL) L-2 cells. When AdCMVmIL2-infected mMTC cells were injected s.c. into their host animals, tumors developed in 2 of 10 animals, in contrast to 9 of 10 animals injected with AdCMVbeta-gal-infected mMTC cells and all 10 animals injected with parental mMTC cells. Moreover protected animals developed a long lasting immunity against mMTC tumor cells and their splenocytes, showing cytotoxicity to parental tumor cells, and active natural killer (NK) cell activity. BALB/c-SCID (severe combined immune deficiency) mice were also used to evaluate the function of NK cells in antitumor activities. No tumor developed in SCID mice injected with AdCMVmIL2-infected cells, whereas all animals injected with either AdCMVbeta-gal-infected or parental mMTC cells developed tumors. Our data indicate that IL-2 production by MTC cells leads to rejection in syngeneic animals and suggest that both cytotoxic T cells and NK cells may play an important role. In addition, transduction of adenoviral vectors into tumor cells produces some nonspecific antitumor effects.
我们评估了使用复制缺陷型腺病毒载体进行基因转导作为甲状腺髓样癌（MTC，一种甲状腺C细胞肿瘤）新型治疗方法的可行性。通过同源重组构建了复制缺陷型腺病毒，使其在人巨细胞病毒（CMV）启动子的控制下表达小鼠白细胞介素-2（mIL-2）基因和大肠杆菌β-半乳糖苷酶（β-gal；lacZ）基因（AdCMVmIL2、AdCMVβ-gal）。使用AdCMVβ-gal在不同条件下评估转导效率。基因转导效率取决于感染复数、病毒暴露时间和病毒浓度。转导的肿瘤细胞中功能性mIL-2的表达在体外和体内均得到验证。两种细胞系（大鼠MTC和mMTC）转导后分泌大量功能性mIL-2，如在细胞毒性T淋巴细胞（CTL）L-2细胞试验中所示。当将AdCMVmIL2感染的mMTC细胞皮下注射到其宿主动物体内时，10只动物中有2只长出肿瘤，相比之下，注射AdCMVβ-gal感染的mMTC细胞的10只动物中有9只长出肿瘤，而注射亲代mMTC细胞的所有10只动物都长出肿瘤。此外，受到保护的动物对mMTC肿瘤细胞及其脾细胞产生了持久的免疫力，对亲代肿瘤细胞表现出细胞毒性，并具有活跃的自然杀伤（NK）细胞活性。还使用BALB/c-SCID（严重联合免疫缺陷）小鼠评估NK细胞在抗肿瘤活性中的功能。注射AdCMVmIL2感染细胞的SCID小鼠未长出肿瘤，而注射AdCMVβ-gal感染或亲代mMTC细胞的所有动物都长出了肿瘤。我们的数据表明，MTC细胞产生的IL-2导致同基因动物中的排斥反应，并表明细胞毒性T细胞和NK细胞可能都发挥重要作用。此外，腺病毒载体转导到肿瘤细胞中会产生一些非特异性抗肿瘤作用。
