Experimental Efficacy of Fiber-modified Cancer-selectively Replicating Adenovirus for Gene Therapy of Biliary Cancers

胆道肿瘤是一种预后差的高度恶性疾病。我们之前已经引入了E1A， e1b -双限制性溶瘤腺病毒AxdAdB3，该病毒在一半的胆道癌细胞系中表现出出色的感染性和溶瘤效果，并且对正常细胞具有增强的安全性。本研究的目的是评估RGD-纤维修饰AxdAdB3 (AxdAdB3- f /RGD)，使整合素依赖性感染，是否可以提高AxdAdB3治疗胆道癌的感染性和疗效。用野生型纤维或rgd修饰纤维表达lacz的复制缺陷腺病毒的感染性水平，比较了腺病毒受体、柯萨奇病毒腺病毒受体（CAR）和整合素（avb3、avb5）在体外一组胆道癌细胞中的表达。研究了一种具有RGD修饰纤维的新型E1A、E1B双限制性腺病毒AxdAdB3-F/RGD在不同胆道癌细胞和正常细胞中的体外复制和细胞毒性，并与其亲本病毒AxdAdB-3进行了比较。在异种移植肿瘤模型中比较了这些溶瘤病毒的体内抗肿瘤作用。CAR的表达与Ad的感染性显著相关，而整合素αvβ5在所有胆道癌细胞中均有丰富表达。虽然AxdAdB3仅在保留CAR表达的胆道癌细胞中有效地复制和裂解，但AxdAdB3- f /RGD在CAR阳性和CAR阴性胆道癌细胞中均表现出高效的复制和有效的溶瘤作用。AxdAdB3- f /RGD在人正常细胞（如肝细胞、WI-38细胞）和AxdAdB3中复制减弱，细胞病变小。此外，在皮下移植car缺陷人胆道癌的裸鼠中，AxdAdB3-F/RGD治疗可显著抑制肿瘤生长。总之，RGD纤维修饰策略增强了E1A、e1b双突变腺病毒对car缺陷胆道癌的感染性、复制性和溶瘤效果。此外，它还保留了双限制性病毒对正常细胞极好的安全性。这些结果表明这种药物可能用于胆道癌的治疗。少

Cancers of biliary system represent highly malignant diseases of dismal prognosis. We have previously introduced an E1A, E1B-double restricted oncolytic adenovirus, AxdAdB3, which showed excellent infectivity and oncolytic efficacy in half of the biliary cancer lines with an enhanced safety to normal cells. The purpose of this study was to evaluate whether RGD-fiber modification of AxdAdB3 (AxdAdB3-F/RGD), which enables integrin-dependent infection, can to improve the infectivity and efficacy of AxdAdB3 for biliary cancers. Expressions of adenoviral receptors, coxsackievirus adenovirus receptor (CAR) and integrins (avb3, avb5), were compared with the level of infectivity of LacZ-expressing replication-defective adenoviruses with wild type fibers or RGD-modified fibers in a panel of biliary cancer cell lines in vitro. Viral replication and cytotoxicity of AxdAdB3-F/RGD, a novel E1A, E1B double restricted adenovirus with RGD-modified fibers, in various biliary cancer cells and in normal … More cells, were compared with those of its parent virus, AxdAdB-3, in vitro. Antitumor effects in vivo of these oncolytic viruses were compared in a xenograft tumor model. Expression of CAR significantly correlated with the Ad infectivity, while integrin αvβ5 was abundantly expressed in all biliary cancer cells. While AxdAdB3 effectively replicated and lysed only the biliary cancer cells with a preserved expression of CAR, AxdAdB3-F/RGD exhibited efficient replication and potent oncolysis in both CAR-positive and CAR-negative biliary cancer cells. AxdAdB3-F/RGD showed attenuated replication and little cytopathy in human normal cells (ie ; hepatocytes, WI-38 cells) as well as AxdAdB3. Furthermore, in nude mice with subcutaneous xenografts of CAR-deficient human biliary cancer, i.t. AxdAdB3-F/RGD therapy caused a marked inhibition of tumor growth. In conclusion, the RGD fiber modification strategy exhibited enhanced infectivity, replication, and oncolytic efficacy of the E1A, E1B-double mutated adenovirus for CAR-deficient biliary cancers. In addition, it preserved the merit of excellent safety of the double-restricted virus for normal cells. These results suggest a potential use of this agent for the treatment of biliary cancers. Less