肿瘤特异性启动子驱动的腺病毒治疗胰岛素瘤。

Tumor-specific promoter-driven adenoviral therapy for insulinoma.

机构信息

The Research Institute for Children, Children's Hospital, 200 Henry Clay Avenue, New Orleans, LA, 70118, USA.

Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, USA.

出版信息

Cell Oncol (Dordr). 2016 Jun;39(3):279-86. doi: 10.1007/s13402-016-0274-8. Epub 2016 Feb 22.

DOI:10.1007/s13402-016-0274-8

PMID:26902080

Abstract

BACKGROUND

Insulinomas are the most common type of neuroendocrine (NE) pancreatic islet tumors. Patients with insulinomas may develop complications associated with hyperinsulinemia. To increase the treatment options for insulinoma patients, we have tested a conditionally replicating adenovirus that has been engineered in such a way that it can specifically express therapeutic genes in NE tumors.

METHODS

We used a promoter-specific adenoviral vector delivery system that is regulated by an INSM1 (insulinoma-associated-1) promoter, which is silent in normal adult tissues but active in developing NE cells and tumors. Through a series of modifications, using an insulator (HS4) and neuron-restrictive silencer elements (NRSEs), an oncolytic adenoviral vector was generated that retains tumor specificity and drives the expression of a mutated adenovirus E1A gene (Δ24E1A) and the herpes simplex virus thymidine kinase (HSV-tk) gene. The efficacy of this vector was tested in insulinoma-derived MIN, RIN, βTC-1 and pancreatic (Panc-1) cells using in vitro cell survival and in vivo tumor growth assays.

RESULTS

Using in vitro insulinoma-derived cell lines and an in vivo subcutaneous mouse tumor model we found that the INSM1 promoter-driven viruses were able to replicate specifically in INSM1-positive cells. INSM1-specific HSV-tk expression in combination with ganciclovir treatment resulted in dose-dependent tumor cell killing, leaving INSM1-negative cells unharmed. When we combined the INSM1-promoter driven HSV-tk with Δ24E1A and INSM1p-HSV-tk (K5) viruses, we found that the co-infected insulinoma-derived cells expressed higher levels of HSV-tk and exhibited more efficient tumor suppression than cells infected with INSM1p-HSV-tk virus alone.

CONCLUSIONS

INSM1 promoter-driven conditionally replicating adenoviruses may serve as a new tool for the treatment of insulinoma and may provide clinicians with additional options to combat this disease.

摘要

背景

胰岛素瘤是最常见的神经内分泌（NE）胰岛肿瘤类型。胰岛素瘤患者可能会出现与高胰岛素血症相关的并发症。为了增加胰岛素瘤患者的治疗选择，我们已经测试了一种经过工程改造的条件复制腺病毒，使其能够在 NE 肿瘤中特异性表达治疗基因。

方法

我们使用了一种受 INSM1（胰岛素瘤相关-1）启动子调节的启动子特异性腺病毒载体传递系统，该启动子在正常成年组织中沉默，但在发育中的 NE 细胞和肿瘤中活跃。通过一系列修饰，使用一个绝缘子（HS4）和神经元限制性沉默元件（NRSEs），生成了一种溶瘤腺病毒载体，该载体保留了肿瘤特异性，并驱动突变的腺病毒 E1A 基因（Δ24E1A）和单纯疱疹病毒胸苷激酶（HSV-tk）基因的表达。我们使用体外细胞存活和体内肿瘤生长测定法，在胰岛素瘤衍生的 MIN、RIN、βTC-1 和胰腺（Panc-1）细胞中测试了这种载体的疗效。

结果

使用体外胰岛素瘤衍生细胞系和体内皮下小鼠肿瘤模型，我们发现 INSM1 启动子驱动的病毒能够特异性地在 INSM1 阳性细胞中复制。INSM1 特异性 HSV-tk 表达与更昔洛韦治疗相结合，导致肿瘤细胞杀伤呈剂量依赖性，而 INSM1 阴性细胞未受伤害。当我们将 INSM1 启动子驱动的 HSV-tk 与 Δ24E1A 和 INSM1p-HSV-tk（K5）病毒结合使用时，我们发现共感染的胰岛素瘤衍生细胞表达更高水平的 HSV-tk，并表现出比单独感染 INSM1p-HSV-tk 病毒的细胞更有效的肿瘤抑制作用。