Liu Shi-He, Davis Alan, Li Zhijun, Ballian Nikiforos, Davis Elizabeth, Wang Xiao-Ping, Fisher William, Brunicardi F Charles
Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030, USA.
J Surg Res. 2007 Jul;141(1):45-52. doi: 10.1016/j.jss.2007.02.041. Epub 2007 May 18.
Studies have demonstrated that adenovirus subtype 5 mediated rat insulin promoter directed thymidine kinase (A-5-RIP-TK)/ganciclovir (GCV) gene therapy resulted in significant enhanced cytotoxicity to both PANC-1 and MIA PaCa2 pancreatic cancer cells in vitro. However, little is known about the effect in vivo. In this study we examine the in vivo safety and efficacy of intravenous A-5-RIP-TK/GCV gene therapy.
1 x 10(6) Mia PaCa2 cells were injected intraperitoneally (i.p.) into SCID mice to create a mouse model of human pancreatic cancer. A-5-RIP-TK gene construct was administered intravenously (i.v.), followed by i.p. GCV administration. Intravenous injection of A-5-RIP-lacZ reporter gene constructs was used for evaluation of Ad-RIP-gene expression in tumors and other tissues. Optimal adenoviral and GCV doses and treatment duration were determined. Tumor volume, serum insulin, and glucose levels were measured. Immunohistochemical staining of pancreata and tumors were performed to assess morphology and hormone expression and apoptotic rates were determined.
All A-5-RIP-TK/GCV-treated mice had reduced tumor volume compared with controls, but maximal tumor volume reduction was observed with 10(8) vp followed by GCV treatment for 4 wk. A-5-RIP-TK/GCV gene therapy contributed to significant survival advantage in MIA PaCa2 bearing mice, and the greatest survival benefit was observed with 10(8) vp and was not affected by length of treatment of GCV. A-5-RIP-TK/GCV therapy increased PDX-1 expression and tumor cells apoptosis, and altered islet morphology. However, A-5-RIP-TK/GCV gene therapy caused diabetes associated with islet cell apoptosis, increased delta-cells and reduced pancreatic polypeptide (PP)-cell numbers.
Systemically administered A-5-RIP-TK/GCV is an effective treatment of pancreatic cancer. A-5-RIP-TK/GCV cytotoxicity to malignant cells varies with adenoviral dose and length of GCV treatment. However, A-5-RIP-TK/GCV is associated with islet cell toxicity and diabetogenesis. The type of diabetes observed is distinct from Types 1 and 2 and is associated with islet cell apoptosis and reduced delta- and PP-cells.
研究表明，腺病毒5型介导的大鼠胰岛素启动子定向胸苷激酶（A-5-RIP-TK）/更昔洛韦（GCV）基因治疗在体外对PANC-1和MIA PaCa2胰腺癌细胞具有显著增强的细胞毒性。然而，其体内效果却知之甚少。在本研究中，我们检测静脉注射A-5-RIP-TK/GCV基因治疗的体内安全性和疗效。
将1×10(6)个Mia PaCa2细胞腹腔注射到SCID小鼠体内，建立人胰腺癌小鼠模型。静脉注射A-5-RIP-TK基因构建体，随后腹腔注射GCV。静脉注射A-5-RIP- lacZ报告基因构建体用于评估Ad-RIP基因在肿瘤及其他组织中的表达。确定最佳腺病毒和GCV剂量以及治疗持续时间。测量肿瘤体积、血清胰岛素和葡萄糖水平。对胰腺和肿瘤进行免疫组织化学染色以评估形态学和激素表达，并确定凋亡率。
与对照组相比，所有接受A-5-RIP-TK/GCV治疗的小鼠肿瘤体积均减小，但在注射10(8)个病毒粒子（vp）并给予GCV治疗4周后观察到最大肿瘤体积减小。A-5-RIP-TK/GCV基因治疗使荷MIA PaCa2小鼠具有显著的生存优势，在注射10(8) vp时观察到最大生存获益，且不受GCV治疗时长的影响。A-5-RIP-TK/GCV治疗增加了PDX-1表达和肿瘤细胞凋亡，并改变了胰岛形态。然而，A-5-RIP-TK/GCV基因治疗导致与胰岛细胞凋亡相关的糖尿病，增加了δ细胞数量并减少了胰腺多肽（PP）细胞数量。
全身给药的A-5-RIP-TK/GCV是一种有效的胰腺癌治疗方法。A-5-RIP-TK/GCV对恶性细胞的细胞毒性随腺病毒剂量和GCV治疗时长而变化。然而，A-5-RIP-TK/GCV与胰岛细胞毒性和糖尿病发生有关。观察到的糖尿病类型不同于1型和2型糖尿病，与胰岛细胞凋亡以及δ细胞和PP细胞减少有关。
