Studies examining quantitative in vivo imaging of breast cancer-targeted,therapeutic human mast cells

摘要 乳腺癌(BC)在美国仍然是一个严重的健康问题。癌基因HER2/neu 叶酸受体α(FRA)在BC中高表达，是癌症治疗的有效靶点。 人源化IgG1单抗曲妥珠单抗(Herceptin®)已被FDA批准用于 晚期BC和几种人源化抗体对FRA的治疗正在进行临床试验。然而，他们的 疗效有限，靶向HER2/neu和FRA过表达肿瘤的其他策略仍然存在 急需之物。有趣的是，BC肿瘤中高密度的肥大细胞(MC)与良好的 预见书。我们发现人类脂肪细胞可以分化为自体的、功能齐全的MC 能在FceRI刺激下释放抗肿瘤介质TNF-a和GM-CSF并诱导BC细胞 死亡。此外，我们首次展示了原代人类MC及其干细胞前体细胞可以 通过携带绿色荧光(GFP)蛋白的慢病毒载体转导，打开了他们 可以与其他肿瘤杀伤分子(如TRAIL、颗粒酶等)一起转导。创造新的治疗方法 BC通过使用抗肿瘤药物引导免疫逃逸细胞前往肿瘤。但是，重要的是要确定 ADMC将靶向体内的癌细胞，确定这种相互作用的初始药代动力学，并 建立关于疗效的原则证明。我们的总体假设是ADMC可以通过 基因成像模块将允许可视化和量化与荧光素酶的结合 静脉注射后体内转导BC细胞/肿瘤注射。在这里，我们将使用一种新的、更安全的慢病毒 转导ADMC的载体系统带有基因模块，可以在不影响体内可视化的情况下 通过比较它们诱导BC细胞死亡的能力与非转导的BC细胞杀伤能力 ADMC。此外，我们将在体内可视化和量化ADMC与BC细胞的结合，并评估 异种移植瘤模型的毒理学活性。

ABSTRACT Breast cancer (BC) continues to be a serious health problem in the United States. The oncogene HER2/neu and the folate receptor alpha (FRa) are overexpressed in BC and validated targets for cancer therapeutics. The humanized IgG1 monoclonal antibody (Ab) trastuzumab (Herceptin®) has been approved by the FDA for the treatment of advanced BC and several humanized IgG Abs to FRa are in clinical trials. However, their efficacy is limited and additional strategies to target HER2/neu and FRa overexpressing tumors are still urgently needed. Interestingly, high densities of mast cells (MC) in BC tumors are associated with favorable prognoses. We discovered that human adipose cells can be differentiated into autologous, fully functional MC capable of releasing anti-tumor mediators TNF-a and GM-CSF upon FceRI stimulation and inducing BC cell death. In addition, we have shown for the first time that primary human MC and their stem cell precursors can be transduced with a lentiviral vector carrying green fluorescence (GFP) protein opening up the possibility they could be transduced with other tumor killing molecules (e.g. TRAIL, granzyme, etc.) to create new ways to treat BC by directing immune evading cells with anti-tumor agents to tumors. However, it is important to determine if the ADMC will target cancer cells in vivo, determine the initial pharmacokinetics of this interaction, and establish proof-of-principle in regards to efficacy. Our overall hypothesis is ADMC can be transduced with genetic imaging modules that will allow for the visualization and quantification of binding to luciferase transduced BC cells/tumors in vivo after i.v. injection. Herein, we will use a novel and safer lentivirus vector system to transduce ADMC with genetic modules that will allow for in vivo visualization without affecting BC cell killing capabilities by comparing their ability to induce BC cell death compared to non-transduced ADMC. Further, we will visualize and quantify ADMC binding to BC cells in vivo and assess overt signs of toxicology activity in xenograft tumor models.