Gene Therapy for Human Lung Adenocarcinoma Using a Suicide Gene Driven by a Lung-Specific Promoter Delivered by JC Virus-Like Particles.

Chun-Nun Chao,Pei-Lain Chen,Meilin Wang,Deching Chang,Cheng-Huang Shen,Mien-Chun Lin,Chiung-Yao Fang

doi:10.1371/journal.pone.0157865

Abstract

Lung adenocarcinoma, the most commonly diagnosed type of lung cancer, has a poor prognosis even with combined surgery, chemotherapy, or molecular targeted therapies. Most patients are diagnosed with an in-operable advanced or metastatic disease, both pointing to the necessity of developing effective therapies for lung adenocarcinoma. Surfactant protein B (SP-B) has been found to be overexpressed in lung adenocarcinoma. In addition, it has also been demonstrated that human lung adenocarcinoma cells are susceptible to the JC polyomavirus (JCPyV) infection. Therefore, we designed that the JCPyV virus-like particle (VLP) packaged with an SP-B promoter–driven thymidine kinase suicide gene (pSPB-tk) for possible gene therapy of human lung adenocarcinoma. Plasmids expressing the GFP (pSPB-gfp) or thymidine kinase gene (pSPB-tk) under the control of the human SP-B promoter were constructed. The promoter’s tissue specificity was tested by transfection of pSPB-gfp into A549, CH27, and H460 human lung carcinoma cells and non-lung cells. The JCPyV VLP’s gene transfer efficiency and the selective cytotoxicity of pSPB-tk combined with ganciclovir (GCV) were tested in vitro and in a xenograft mouse model. In the current study, we found that SP-B promoter–driven GFP was specifically expressed in human lung adenocarcinoma (A549) and large cell carcinoma (H460) cells. JCPyV VLPs were able to deliver a GFP reporter gene into A549 cells for expression. Selective cytotoxicity was observed in A549 but not non-lung cells that were transfected with pSPB-tk or infected with pSPB-tk–carrying JCPyV VLPs. In mice injected with pSPB-tk–carrying JCPyV VLPs through the tail vein and treated with ganciclovir (GCV), a potent 80% inhibition of growth of human lung adenocarcinoma nodules resulted. The JCPyV VLPs combined with the use of SP-B promoter demonstrates effectiveness as a potential gene therapy against human lung adenocarcinoma.

Highlights

Lung cancer is the leading cause of mortality due to malignancy worldwide [1]
These results showed that the cloned Surfactant protein B (SP-B) promoter confers tissue-specific cytotoxicity in A549 and H460 cells
These results support the potential usefulness of the SP-B promoter–driven suicide gene carried by JC polyomavirus (JCPyV) virus-like particle (VLP) as a gene therapy strategy for treating human lung adenocarcinoma

Summary

Introduction

Lung cancer is the leading cause of mortality due to malignancy worldwide [1]. Non–small cell lung cancer (NSCLC) accounts for approximately 80% of lung cancer cases diagnosed. Adenocarcinoma is the most common type of lung cancer seen in non-smokers and women, and the relative incidence of adenocarcinoma has risen dramatically in recent decades [2]. The treatment of choice for early-stage NSCLC is surgical resection supplemented by adjuvant cisplatin-based chemotherapy, which improves the patients’ 5-year survival, but by only 4–5% [3]. Surgery is the best possible treatment, only 20–25% of NSCLC patients are suitable for potentially curative resection [4]. Patients with advanced lung cancer, who are not good candidates for resection, generally have a poor prognosis or eventually develop resistant disease even when treated with newer chemotherapeutic agents or molecular targeted therapies [5,6,7]. With an overall 5-year survival rate of less than 15% [8], these patients are clearly in need of new, effective therapeutic options

Methods

Results

Conclusion