FHIT Gene Therapy in Cancer Prevention and Treatment

FHIT基因治疗在肿瘤防治中的应用我们已经研制出小鼠上消化系统 口服/V-亚硝基甲基苄胺(NMBA)或4-硝基喹啉-1-氧化物(NQO)诱导的小鼠膀胱癌模型 治疗。野生型(WT)小鼠对这些致癌物不是很敏感，但两者都缺乏 在暴露于NMBA或NQO的情况下，FHIT或P53的肿瘤负担比WT小鼠高出10倍 可预测的时间表。早期FHIT治疗可显著减轻小鼠前胃肿瘤负担 致癌物暴露后(肿瘤预防)或晚期(肿瘤消退)，以及肺癌和宫颈癌 研究正在进行中。对小鼠临床前模型的一个警告是，普遍认为小鼠肿瘤 表现出比人类同行更少的遗传复杂性和异质性，因此人类癌症可能是 对FHIT基因治疗反应较差。拟议的研究旨在通过测试FHIT来解决这一问题 FHIT+/-xTrp53+/-重组小鼠杂交瘤的基因治疗 诱导前胃和口腔癌，表明FHIT，作为一种守门人基因产物，其丢失启动 AAVFHIT交付后的肿瘤过程，可以预防或逆转肿瘤 FHIT基因座在暴露于基因毒剂和FHIT时极易造成复制损伤 在上呼吸道肿瘤癌前病变发生的早期，蛋白质丢失或减少。 该项目的研究基于以下假设：在这些病变中替换FHIT可能：a) 根除这些器官“癌灶”中的变异细胞，从而防止复发；b)逆转 已建立的癌症的进展；c)允许识别FHIT丢失在 FHIT基因治疗前后FHIT基因缺陷动物的创业发育及蛋白质的变化 FHIT信号通路药理再激活的靶点。 因此，本研究项目的目的是：1)预防和逆转癌前病变和肿瘤 FHIT基因治疗对FHIT+/-和FHIT+/-P53+/-小鼠前胃损伤的影响 NQO诱导抑癌基因缺陷小鼠口腔癌的方案及预防和逆转 FHIT基因治疗FHIT+/-和FHIT+/-P53+/-小鼠口腔癌和肿瘤； 3)多重FHIT基因治疗NMBA和NQO损伤的FHIT和FHIT/P53缺陷小鼠 治疗剂量或FHIT基因治疗加FHIT途径靶向药物治疗。在每一个特定的目标中-/- 小鼠将被包括在内，接受和不接受FHIT基因治疗的小鼠的组织将被评估 细胞周期、DNA损伤反应和凋亡相关蛋白的表达以及FHIT-1 相互作用的蛋白质以识别因FHIT缺失而改变、通过FHIT替换而恢复的信号通路， 并可能作为治疗上消化道和其他癌症的药物靶点。

FHIT Gene Therapy in Cancer Prevention and Treatment. We have developed murine upper digestive tract cancer models induced by oral /V-nitrosomethylbenzylamine(NMBA) or 4-nitroquinoline 1-oxide (NQO) treatment. Wild type (WT) mice are not very susceptible to these carcinogens but mice deficient for either Fhit or p53 develop a tumor burden up to 10 times greater than WT mice on exposure to NMBA or NQO, on predictable schedules. Mouse forestomach tumor burden is dramatically reduced by FHIT therapy early (tumor prevention) or late (tumor regression) after carcinogen exposure, and lung and cervical cancer studies are in progress. A caveat to mouse preclinical models is the prevailing notion that mouse tumors exhibit less genetic complexity and heterogeneity than human counterparts, so that human cancers may be less responsive to FHIT gene therapy. The proposed study aims to address this concern by testing FHIT gene therapy in genetically complex mouse tumors in the recombinant mouse cross, Fhit+/-xTrp53+/-, with induced forestomach and oral cancers, to show that Fhit, as a gatekeeper gene product whose loss initiates the neoplastic process, can prevent or reverse tumors after AAVFHIT delivery The FHIT locus is exquisitely susceptible to replication damage on exposure to genotoxic agents and Fhit protein is lost or reduced early in development of precancerous lesions of upper aerodigestive tract tumors. Research in this Project is based on the hypotheses that replacement of FHIT in these lesions could: a) eradicate the altered cells in the "cancer field" of these organs, thus preventing recurrences; b) reverse progression of established cancers; c) allow identification of pathways altered by Fhit loss during development of preneoplasia in Fhit deficient animals, before and after FHIT gene therapy, and of protein targets for pharmacological reactivation of Fhit signal pathways. Thus the aims of this research project are to: 1) prevent and reverse preneoplastic and neoplastic lesions, respectively, in forestomachs of Fhit+/- and Fhit+/-p53+/-mice by FHIT gene therapy; 2) optimize the protocol for NQO induction of oral cancers in the tumor suppressor deficient mice and prevent and reverse preneoplasias and neoplasias of the oral cavity in Fhit+/- and Fhit+/-p53+/-mice by FHIT gene therapy; 3) "cure" the Fhit and Fhit/p53 deficient mice of NMBA and NQO-induced lesions by multiple FHIT gene therapy doses or FHIT gene therapy plus Fhit pathway targeted drug treatment. In each specific aim Fhit-/- mice will be included and tissues from mice with and without FHIT gene therapy will be assessed for expression of cell cycle, DNA damage response and apoptosis-associated proteins, as well as Fhit- interacting proteins to identify the signal pathways altered by Fhit absence, restored by Fhit replacement, and likely to serve as drug targets for treatment of upper digestive tract and other cancers.