Enhanced growth suppression in esophageal carcinoma cells using adenovirus-mediated fusion gene transfer (uracil phosphoribosyl transferase and herpes simplex virus thymidine kinase)

Update on gastric cancer treatments and gene therapies

Gastric cancer is an active topic of clinical and basic research due to high morbidity and mortality. To date, gastrectomy and chemotherapy are the only therapeutic options for gastric cancer patients, but drug resistance, either acquired or primary, is the main cause for treatment failure. Differences in development and response to cancer treatments have been observed among ethnically diverse GC patient populations. In spite of major incidence, GC Asian patients have a significantly better prognosis and response to treatments than Caucasian ones due to genetic discordances between the two populations. Gene therapy could be an alternative strategy to overcome such issues and especially CRISPR/Cas9 represents one of the most intriguing gene-editing system. Thus, in this review article, we want to provide an update on the currently used therapies for the treatment of advanced GC. Graphical abstract.

Therapeutic targeting of liver cancer with a recombinant DNA vaccine containing the hemagglutinin-neuraminidase gene of Newcastle disease virus via apoptotic-dependent pathways

A total of ~38.6 million mortalities occur due to liver cancer annually, worldwide. Although a variety of therapeutic methods are available, the efficacy of treatment at present is extremely limited due to an increased risk of malignancy and inherently poor prognosis of liver cancer. Gene therapy is considered a promising option, and has shown notable potential for the comprehensive therapy of liver cancer, in keeping with advances that have been made in the development of cancer molecular biology. The present study aimed to investigate the synergistic effects of the abilities of the hemagglutinin neuraminidase protein of Newcastle disease virus (NDV), the pro-apoptotic factor apoptin from chicken anaemia virus, and the interferon-γ inducer interleukin-18 (IL-18) in antagonizing liver cancer. Therefore, a recombinant DNA plasmid expressing the three exogenous genes, VP3, IL-18 and hemagglutinin neuraminidase (HN), was constructed. Flow cytometry, acridine orange/ethidium bromide staining and analysis of caspase-3 activity were performed in H22 cell lines transfected with the recombinant DNA plasmid. In addition, 6-week-old C57BL/6 mice were used to establish a H22 hepatoma-bearing mouse model. Mice tumor tissue was analyzed by immunohistochemistry and scanning electron microscopy. The results of the present study revealed that the recombinant DNA vaccine containing the VP3, IL-18 and HN genes inhibited cell proliferation and induced autophagy via the mitochondrial pathway in vivo and in vitro.

The establishment of a new mouse model with orthotopic esophageal cancer showing the esophageal stricture

We established a promising new experimental animal model with an orthotopic xenograft of esophageal cancer that successfully represents poor oral intake, a major clinical feature of esophageal cancer. The advantage of this model is that no surgical technique is required, only the injection of a cell suspension by a needle and syringe via the esophageal lumen from the mouth, which provides a high reproducibility of tumor implantation and a rapid progress of outcome. We propose that this model is useful to study cancer-related outcomes and for developing new therapies for esophageal cancer, and we expect it to make a contribution to clinical practice.

Accumulation of infectious mutants in stocks during the propagation of fiber-modified recombinant adenoviruses

In infected cells, replication errors during viral proliferation generate mutations in adenoviruses (Ads), and the mutant Ads proliferate and evolve in the intracellular environment. Genetically fiber-modified recombinant Ads (rAd variants) were generated, by modification of the fiber gene, for therapeutic applications in host cells that lack or express reduced levels of the Coxsackievirus and adenovirus receptor. To assess the genetic modifications of rAd variants that might induce the instability of Ad virions, we examined the frequencies of mutants that accumulated in propagated stocks. Seven of 41 lines of Ad variants generated mutants in the stocks and all mutants were infectious. Moreover, all the mutations occurred in the modified region that had been added at the 3' end of the fiber gene. Our results show that some genetic modifications at the carboxyl terminus of Ad fiber protein lead to the instability of Ad virions.

Gene therapy for gastric cancer: A review

Gastric cancer is common in China, and its early diagnosis and treatment are difficult. In recent years great progress has been achieved in gene therapy, and a wide array of gene therapy systems for gastric cancer has been investigated. The present article deals with the general principles of gene therapy and then focuses on how these principles may be applied to gastric cancer.

p53 gene therapy for esophageal cancer

Despite improvement of surgical treatment and application of multimodality therapies to advanced esophageal cancer, the prognosis is extremely poor for patients with unresectable tumors. Based on the genetic background of esophageal cancer, we have developed various gene therapy strategies against human esophageal cancer. In this article, we review molecular events of esophageal cancer and p53 gene therapy approaches for its treatment. First, we analyzed p53 genetic alterations and angiogenesis in esophageal cancer. Second, we tested a p53 recombinant adenoviral vector (Ad5CMV-p53). Significant growth suppression was observed following infection with Ad5CMV-p53 in human esophageal cancer cell lines. This observation suggests that Ad5CMV-p53 may be a potentially effective therapeutic agent for locally advanced esophageal cancer. Promising avenues for investigation include double gene therapy and adjuvant use of gene therapy with radiation therapy. Third, based on recent reports of clinical trials of p53 gene therapy for lung cancer and head and neck cancer, we developed a clinical protocol for p53 gene therapy for unresectable advanced esophageal cancer. This clinical trial was planned to evaluate vector tolerability and efficacy. Up to December 1, 2001, four patients were enrolled in this phase I/II trial. No serious adverse events related to Ad5CMV-p53 have occurred so far in these patients, and the trial has been safely conducted.