Egami Takuya, Ohuchida Kenoki, Yasui Takaharu, Mizumoto Kazuhiro, Onimaru Manabu, Toma Hiroki, Sato Norihiro, Matsumoto Kunio, Tanaka Masao
Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Cancer Sci. 2009 Oct;100(10):1902-7. doi: 10.1111/j.1349-7006.2009.01245.x. Epub 2009 Jun 17.
Adenovirus-mediated gene therapy is a promising approach for the treatment of pancreatic cancer. We previously reported that radiation enhanced adenovirus-mediated gene expression in pancreatic cancer, suggesting that adenoviral gene therapy might be more effective in radioresistant pancreatic cancer cells. In the present study, we compared the transduction efficiency of adenovirus-delivered genes in radiosensitive and radioresistant cells, and investigated the underlying mechanisms. We used an adenovirus expressing the hepatocyte growth factor antagonist, NK4 (Ad-NK4), as a representative gene therapy. We established two radioresistant human pancreatic cancer cell lines using fractionated irradiation. Radiosensitive and radioresistant pancreatic cancer cells were infected with Ad-NK4, and NK4 levels in the cells were measured. In order to investigate the mechanisms responsible for the differences in the transduction efficiency between these cells, we measured expression of the genes mediating adenovirus infection and endocytosis. The results revealed that NK4 levels in radioresistant cells were significantly lower (P < 0.01) than those in radiosensitive cells, although there were no significant differences in adenovirus uptake between radiosensitive cells and radioresistant cells. Integrin beta3 was up-regulated and the Coxsackie virus and adenovirus receptor was down-regulated in radioresistant cells, and inhibition of integrin beta3 promoted adenovirus gene transfer. These results suggest that inhibition of integrin beta3 in radioresistant pancreatic cancer cells could enhance adenovirus-mediated gene therapy.
腺病毒介导的基因治疗是一种很有前景的胰腺癌治疗方法。我们之前报道过，放疗可增强腺病毒介导的胰腺癌基因表达，这表明腺病毒基因治疗在放射抗性胰腺癌细胞中可能更有效。在本研究中，我们比较了腺病毒递送基因在放射敏感和放射抗性细胞中的转导效率，并研究了其潜在机制。我们使用表达肝细胞生长因子拮抗剂NK4的腺病毒（Ad-NK4）作为代表性的基因治疗手段。我们通过分次照射建立了两种放射抗性人胰腺癌细胞系。用Ad-NK4感染放射敏感和放射抗性胰腺癌细胞，并检测细胞中的NK4水平。为了研究造成这些细胞转导效率差异的机制，我们检测了介导腺病毒感染和内吞作用的基因表达。结果显示，尽管放射敏感细胞和放射抗性细胞在腺病毒摄取方面没有显著差异，但放射抗性细胞中的NK4水平显著低于放射敏感细胞（P < 0.01）。放射抗性细胞中整合素β3上调，柯萨奇病毒和腺病毒受体下调，抑制整合素β3可促进腺病毒基因转移。这些结果表明，抑制放射抗性胰腺癌细胞中的整合素β3可增强腺病毒介导的基因治疗。
