表达CD40L/Dm-dNK瘤裂解腺病毒乳腺癌的靶向免疫及分子治疗

乳腺癌是世界范围的主要健康难题。早期肿瘤辅助治疗的小分子靶向治疗可以减少复发延长生存，而晚期及复发者尚不能治愈。肿瘤选择性生物及基因治疗为乳腺癌带来了新曙光。免疫抑制环境的产生是肿瘤免疫治疗的主要障碍。腺病毒E1A基因可以下调Her-2基因并已进入I期临床试验。CD40配体(CD40L)用于免疫调节及协调上皮细胞生长分化。以前的研究显示瘤裂解腺病毒装配黑腹果蝇脱氧核苷酸激酶(Dm-dNK)保持肿瘤杀伤活性，但加药可抑制腺病毒的复制。该项目将评估瘤裂解腺病毒装载CD40L 及Dm-dNK新的体系。Dm-dNK将可能作为TK类似物促进病毒复制，而又可作为安全控制机制及分子化疗的抗肿瘤杀伤机制。本项目将证实AdCD40L-dNK体系的多重抗肿瘤特性；这一携带多功能免疫激活因子CD40L和Dm-dNK/癌前药物的分子化疗特性新的治疗体系AdCD40L-dNK可能成为乳腺癌临床前试验的潜在治疗新策略

Breast cancer is a major health problem worldwide. Small targeted molecules in an adjuvant setting have shown to extend relapse-free survival of patients with early-stage disease; however, therapeutic options for advanced, metastatic malignancies remain incurable. Cancer-selective biotherapy or gene therapy approaches have been considered to be the next horizon toward developing a cure for breast cancer. The immunosuppressive environment of breast cancer is a primary obstacle to the efficacy of immunostimulatory and vaccine approaches. The capacity of the adenoviral early gene E1A to down-regulate Her-2/neu activity has led to phase I clinical trial for breast cancers in this regard. CD40 ligand (CD40L) plays a central role in immunoregulation and also directly modulates epithelial cell growth and differentiation; We previously showed that the oncolytic adenovirus armed with Deoxyribonucleoside Kinase of Drosophila Melanogaster （Dm-dNK) produced a synergistic inhibitive effect of adenovirus replication when combining with anti-virus nucleoside analogs, while maintaining specific cancer cell killing activity, and the CD40 receptor is commonly expressed in primary breast cancer tissues. Here we evaluate a novel approach to arm an oncolytic adenovirus with CD40L and Dm-dNK to stimulate beneficial immunological responses in vitro and in vivo. A double targeted chimeric adenovirus controlled by the hTERT promoter and expressing CD40L-dNK was constructed, and the breast cancer growth regulatory activities of an oncolytic adenoviral construct carrying the CD40L/Dm-dNK transgene (AdCD40L-dNK) will be examined. Dm-dNK will serve as a analog of thymidine kinase (TK) to promote the virus replicate; Dm-dNK/prodrug could also be the last attack to tumor cell and the safety-control of the system. In vitro and in vivo evaluations will be carried out on AdCD40L-dNK to validate selective viral replication and CD40L transgene activity in hypoxia inducing factor and estrogen receptor expressing human breast cancer cells. In this project, we will characterize the antitumor properties of a novel, conditional replicative,oncolytic adenoviral construct (AdCD40L-dNK) carrying the multifunctional molecule CD40L and Dm-dNK in the form of an integrated transgene. This novel strategy together with the previously known immune-activating features of CD40L and molecular chemotherapy of Dm-dNK/prodrug, will support the potential applicability of AdCD40L-dNK for preclinical treatment of human breast cancer.