Department of Gastroenterological Surgery, Graduate School of Medicine, Yokohama-city University, Yokohama, Japan.
Cancer Sci. 2013 Aug;104(8):1083-90. doi: 10.1111/cas.12196. Epub 2013 Jul 3.
Pancreatic cancer has a poor prognosis after complete macroscopic resection combined with chemotherapy. Even after neoadjuvant chemotherapy, R0 resection is often not possible. Moreover, current imaging techniques cannot reliably distinguish viable cancer cells from scar tissue at the resectional margin. We investigated the use of a conditionally replicative adenovirus (CRAd), Ad5/3Cox2CRAd-ΔE3ADP-Luc, for imaging the effects of chemotherapy. The CRAd infectivity of pancreatic cancer cells was enhanced by a chimeric Ad5/3 fiber, E1A expression was under the control of the Cox2 promoter, and the luciferase gene was inserted adjacent to the adenovirus death protein (ADP) gene. Subcutaneous xenografts of the pancreatic cancer cell line MiaPaCa-2 were established in 24 BALB/c nu/nu mice. When xenografts reached a diameter of 4-6 mm (day 1), the mice were injected i.p. with either PBS (group A; n = 12) or 1000 mg/kg gemcitabine (group B; n = 12), weekly. On days 19, 26, 33, and 40, CRAd were injected intratumorally into three mice in groups A and B. Bioluminescence was imaged 72 h after CRAd injection, and gross tumor volumes were measured then tumors were removed for ex vivo histopathology using H&E and Ki-67 staining. Correlations between gross tumor volume, pathological evaluation of the percentage of viable tumor area, and CRAd bioluminescence were analyzed. Bioluminescence correlated closely with the percentage of viable tumor area (R = 0.96), but not with gross tumor volume (R = 0.31). Therefore, CRAds might be reliable imaging tools for monitoring chemotherapy in pancreatic cancer, and could improve our ability to distinguish viable tumor cells from scar tissue.
在完全行宏观切除术联合化疗后，胰腺癌的预后较差。即使在新辅助化疗后，R0 切除也常常无法实现。此外，目前的成像技术无法可靠地区分切除边缘的存活癌细胞和疤痕组织。我们研究了使用条件复制腺病毒（CRAd），Ad5/3Cox2CRAd-ΔE3ADP-Luc，对化疗效果进行成像。嵌合 Ad5/3 纤维增强了 CRAd 的感染力，E1A 表达受 Cox2 启动子的控制，而荧光素酶基因插入到腺病毒死亡蛋白（ADP）基因的旁边。在 24 只 BALB/c nu/nu 小鼠中建立了胰腺癌细胞系 MiaPaCa-2 的皮下异种移植瘤。当异种移植瘤直径达到 4-6mm（第 1 天）时，将小鼠腹腔内注射 PBS（A 组；n = 12）或 1000mg/kg 吉西他滨（B 组；n = 12），每周一次。在第 19、26、33 和 40 天，将 CRAd 瘤内注射到 A 组和 B 组的三只小鼠中。在 CRAd 注射后 72 小时进行生物发光成像，并测量大体肿瘤体积，然后切除肿瘤用于 H&E 和 Ki-67 染色的离体组织病理学检查。分析大体肿瘤体积、存活肿瘤面积百分比的病理评估与 CRAd 生物发光之间的相关性。生物发光与存活肿瘤面积的百分比密切相关（R = 0.96），但与大体肿瘤体积无关（R = 0.31）。因此，CRAd 可能是监测胰腺癌化疗的可靠成像工具，并能提高我们区分存活肿瘤细胞和疤痕组织的能力。
