UCNP标记的ERβ基因对结直肠癌的靶向诊断和治疗作用研究

Colorectal cancer (CRC) is the second most commonly diagnosed cancer among females and third among males worldwide. It also contributes significantly to cancer-related deaths, despite the continuous progress in diagnostic and therapeutic methods. However,there is no effective therapeutic method for patients with colorectal cancer and they generally had unfavourable prognosis. Recently, most of the dosage regimen of gene therapy are intratumor injection, which limited the application of gene therapy for deep tumor. In the present project, Folic Acid (FA) was modified for reconstructed Ad-ERβ to form FA-Ad5-ERβ to achieve the purpose of targeting gene therapy for colorectal cancer through intravenous injection. Low transfection efficiency and time lag between therapy and treatment effect have limited the development of traditional therapeutic method of gene therapy. In this project, the therapeutic efficacies of ERβ will be confirmed in xenograft model of HCT-116 with intravenous injection of FA-Ad5-ERβ-UCNP. Furthermore, the diagnostic and targeted therapeutic efficacy will be monitored with real-time in vivo upconversion luminescence (UCL) imaging system and the mechanism of the anticancer effect of FA-Ad5-ERβ-UCNP also will be investigated.

结直肠癌是常见的恶性肿瘤，发病率在男性癌症发病率中占第二位，女性中占第三位，死亡率也很高。虽然在结直肠癌的诊断和治疗方面的研究也取得了一些进展，但目前国内外仍缺乏针对结直肠癌的有效治疗手段。目前，大多数基因治疗的给药方案都是瘤内注射，这限制了基因治疗方法应用于一些深层肿瘤的治疗。本项目利用叶酸的靶向作用，通过静脉注射给药，实现对结直肠癌的靶向基因治疗。传统的基因治疗方法存在转染效率低下，转染效率及治疗结果要等到后期的药理学实验结束之后才能获知的缺陷。本项目借助上转换纳米荧光探针在体成像系统无损实时在位监测转染效率、转染范围、肿瘤组织血氧等以实时优化治疗方案，并实现对深层肿瘤组织的诊断和监控治疗。此外，本项目首次将ERβ基因导入活体肿瘤模型中，考察其对结直肠癌的生长抑制作用，并对其抑瘤机制进行系统的研究。

结直肠癌是常见的恶性肿瘤，死亡率较高。虽然在结直肠癌的诊断和治疗方面的研究也取得了一些进展，但目前国内外仍缺乏针对结直肠癌的有效治疗手段并且该病的预后一般都较差。目前，大多数基因治疗的给药方案都是瘤内注射，这限制了基因治疗方法应用于一些深层肿瘤的治疗。本研究利用聚丙烯酸（PAA）上的羧基和叶酸修饰的重组腺病毒（FA-Ad5-ERβ）上的氨基反应构建激发和发射光谱均在近红外区的上转换纳米荧光粒子标记的靶向基因治疗药物FA-Ad5-ERβ-UCNP，优化了人ERβ基因的细胞转染效率，优化靶向基因治疗方案。本研究主要在如下几个方面开展了工作并取得了一定的研究成果：1）重组腺病毒（Ad5-ERβ）的构建及表征；2）上转换纳米荧光粒子标记的靶向基因治疗药物FA-Ad5-ERβ-UCNP 的构建及表征；3）体外实验考察FA-Ad5-ERβ-UCNP 对结直肠癌细胞HCT-116 的生长抑制作用；4）体内实验考察FA-Ad5-ERβ-UCNP 对裸鼠结直肠癌细胞HCT-116肿瘤模型的生长抑制作用；5）体外实验考察FA-Ad5-ERβ-UCNP 对结直肠癌细胞HCT-116 的生长抑制作用机理；6）体内实验考察FA-Ad5-ERβ-UCNP 对裸鼠结直肠癌细胞HCT-116肿瘤模型的抑瘤机理；本研究最终制备出激发和发射光谱均在近红外区的具有肿瘤靶向性及治疗作用的上转换纳米荧光探针FA-Ad5-ERβ-UCNP，并制定出用重组腺病毒FA-Ad5-ERβ-UCNP 体内体外治疗结直肠癌的有效方案。