Growth inhibition of human malignant melanoma transfected with the human interferon-beta gene by means of cationic liposomes

Bone marrow-derived mesenchymal stem cells co-expressing interleukin-18 and interferon-β exhibit potent antitumor effect against intracranial glioma in rats

Bone marrow-derived mesenchymal stem cells (BMSCs) are promising gene vehicles for cancer gene therapy. In our previous study, we reported that BMSCs expressing interleukin (IL)-18 effectively inhibit the growth of glioma in rats. In the present study, we further detected the effect of BMSCs co-expressing IL-18 and interferon (IFN)-β, both of which are immunostimulatory cytokines. BMSCs were genetically engineered to express IL-18 and IFN-β by transfection of recombinant lentivirus-mediated gene transfer. Results showed that BMSCs co-expressing the two cytokines displayed more significant inhibition effect on glioma cell growth in vitro when compared with BMSCs solely expressing IL-18 or IFN-β. Treatment of BMSCs co-expressing IL-18 and IFN-β significantly prolonged the survival and inhibited tumor growth in a rat intracranial glioma model. Furthermore, these genetically engineered BMSCs remarkably promoted cell apoptosis, antitumor cytokine production and CD4+ and CD8+ T-cell infiltration in intracranial glioma tissues than BMSCs solely expressing IL-18 or IFN-β. Results of the present study suggested that IL-18 and IFN-β had a synergistic effect on glioma inhibition. Moreover, results provided evidence that delivery of IL-18 and IFN-β by BMSCs may be an excellent and promising approach to develop an effective treatment protocol for glioma therapy.

TRIM16 inhibits proliferation and migration through regulation of interferon beta 1 in melanoma cells

High basal or induced expression of the tripartite motif protein, TRIM16, leads to reduce cell growth and migration of neuroblastoma and skin squamous cell carcinoma cells. However, the role of TRIM16 in melanoma is currently unknown. TRIM16 protein levels were markedly reduced in human melanoma cell lines, compared with normal human epidermal melanocytes due to both DNA methylation and reduced protein stability. TRIM16 knockdown strongly increased cell migration in normal human epidermal melanocytes, while TRIM16 overexpression reduced cell migration and proliferation of melanoma cells in an interferon beta 1 (IFNβ1)-dependent manner. Chromatin immunoprecipitation assays revealed TRIM16 directly bound the IFNβ1 gene promoter. Low level TRIM16 expression in 91 melanoma patient samples, strongly correlated with lymph node metastasis, and, predicted poor patient prognosis in a separate cohort of 170 melanoma patients with lymph node metastasis. The BRAF inhibitor, vemurafenib, increased TRIM16 protein levels in melanoma cells in vitro, and induced growth arrest in BRAF-mutant melanoma cells in a TRIM16-dependent manner. High levels of TRIM16 in melanoma tissues from patients treated with Vemurafenib correlated with clinical response. Our data, for the first time, demonstrates TRIM16 is a marker of cell migration and metastasis, and a novel treatment target in melanoma.

Induction of apoptosis in glioma cells and upregulation of Fas expression using the human interferon-β gene

We investigated whether IFN-β inhibits the growth of human malignant glioma and induces glioma cell apoptosis using the human IFN-β gene transfected into glioma cells. A eukaryonic expression vector (pSV2IFNβ) for IFN-β was transfected into the glioma cell line SHG44 using liposome transfection. Stable transfection and IFN-β expression were confirmed using an enzyme-linked immunosorbent assay (ELISA). Cell apoptosis was also assessed by Hoechst staining and electron microscopy. In vivo experiments were used to establish a SHG44 glioma model in nude mice. Liposomes containing the human IFN-β gene were injected into the SHG44 glioma of nude mice to observe glioma growth and calculate tumor size. Fas expression was evaluated using immunohistochemistry. The IFN-β gene was successfully transfected and expressed in the SHG44 glioma cells in vitro. A significant difference in the number of apoptotic cells was observed between transfected and non- transfected cells. Glioma growth in nude mice was inhibited in vivo, with significant induction of apoptosis. Fas expression was also elevated. The IFN-β gene induces apoptosis in glioma cells, possibly through upregulation of Fas. The IFN-β gene modulation in the Fas pathway and apoptosis in glioma cells may be important for the treatment of gliomas.

Ultrasound-mediated interferon β gene transfection inhibits growth of malignant melanoma

We investigated the effects of ultrasound-mediated transfection (sonotransfection) of interferon β (IFN-β) gene on melanoma (C32) both in vitro and in vivo. C32 cells were sonotransfected with IFN-β in vitro. Subcutaneous C32 tumors in mice were sonicated weekly immediately after intra-tumor injection with IFN-β genes mixed with microbubbles. Successful sonotransfection with IFN-β gene in vitro was confirmed by ELISA, which resulted in C32 growth inhibition. In vivo, the growth ratio of tumors transfected with IFN-β gene was significantly lower than the other experimental groups. These results may lead to a new method of treatment against melanoma and other hard-to-treat cancers.

A pilot study of human interferon beta gene therapy for patients with advanced melanoma by in vivo transduction using cationic liposomes

BACKGROUND

Cationic liposomes containing the human interferon beta (HuIFNbeta) gene (IAB-1) was used for the clinical trial for glioma patients. HuIFNbeta gene therapy showed much higher anti-tumor activity compared with the administration of HuIFNbeta protein for melanoma. These results suggest that HuIFNbeta gene therapy is an attractive strategy for the treatment of melanoma.

METHODS

Stage IV or III melanoma patients with cutaneous or subcutaneous metastatic lesions were enrolled in this pilot study. IAB-1 was dissolved by sterile PBS at a concentration of 30 microg DNA/ml and was injected into cutaneous or subcutaneous metastatic nodules three times a week for 2 weeks and the effect on the injected and non-injected metastatic lesions was evaluated.

RESULTS

Clinical responses were as follows (five patients): mixed response (MR) and no change in each one patient, and progressive disease in three patients. In the MR patient, the IAB-1 injected lesion disappeared clinically and histopathologically and one-half of IAB-1 non-injected skin metastases were transiently inflamed and mostly regressed. In the responded non-injected lesions of this patient, histopathologically, infiltration of CD4 positive T cells was observed around the melanoma cells in the dermis, which expressed the HLA-Class II antigen. Adverse events due to this gene therapy were not recognized in any of the patients.

CONCLUSIONS

The efficacy of this gene therapy was generally insufficient; however, some immunological responses were recognized in one patient. No adverse events were observed. HuIFNbeta gene therapy could be an attractive strategy for treatment of a variety of malignancies, including melanoma, though some modifications should be required.

Susceptibility to exogenously added interferon-beta protein depends on intracellular interferon-beta mRNA level in human glioma cells

Exogenously added human interferon-beta (HuIFN-beta) protein possesses a remarkable antiproliferative activity in human glioma and melanoma. Endogenous HuIFN-beta protein, which is produced by its gene transfer using cationic liposomes, has much more effective antiproliferative activity against these tumors, even in cells resistant to exogenously added HuIFN-beta protein. As the first step to elucidate the possible difference in antiproliferative mechanisms between exogenous and endogenous HuIFN-beta protein, we here investigated the relationship between the intracellular level of its mRNA and susceptibility to exogenously added HuIFN-beta protein. In this study, we used seven human glioma cell lines (SK-MG-1, SK-MG-4, SK-AO2, U87MG, U251SP, U251MG and T98) and one human melanoma cell line (MMAN). At first, we examined the relationship between spontaneous expression of HuIFN-beta mRNA and susceptibility to exogenously added HuIFN-beta protein (50 IU/ml) in human glioma cells and then confirmed a significant correlation between them. Next, we confirmed that administration of 0-100 IU/ml exogenously added HuIFN-beta protein upregulated the HuIFN-beta mRNA in a dose-dependent manner using the RT-PCR technique and that the HuIFN-beta mRNA was suppressed by siRNA for HuIFN-beta in SK-MG-1 and MMAN cells. Furthermore, we confirmed that the siRNA for HuIFN-beta significantly suppressed the antiproliferative effect of SK-MG-1 cells treated with 10-100 IU/ml HuIFN-beta protein and MMAN cells with 25 and 50 IU/ml HuIFN-beta protein. We found this phenomenon in another human glioma cell line, U87MG cells, as well. This finding would suggest that susceptibility to exogenously added HuIFN-beta protein is related to the amount of intracellular HuIFN-beta mRNA in human glioma and melanoma cells.

Interferon-beta gene therapy for cancer: basic research to clinical application

Interferon-beta gene therapy for cancer is the first such protocol developed in Japan. Here we describe the development process of our interferon-beta gene therapy from basic research to clinical application. Interestingly, the biological and biochemical characteristics of interferon-beta gene therapy through transfer of the interferon-beta gene into tumor cells by means of cationic liposomes differed from those of conventional interferon-beta protein therapy. Interferon-beta gene transfer could induce apoptosis in interferon-beta protein-resistant tumor cells, such as glioma, melanoma, and renal cell carcinoma. Induction of apoptosis was related to the level of intracellular mRNA of interferon-beta, prolongation of the phosphorylation time of molecules in the interferon-beta signal transduction pathway, such as JAK1, Trk2, and STAT1, and activation of DNase gamma. In our preclinical study we developed lyophilized cationic liposomes containing interferon-beta gene (gene drug) for clinical use and confirmed their safety. Thereafter, we performed a pilot clinical trial in patients with malignant glioma and confirmed the safety and effectiveness of this interferon-beta gene therapy. In this review we also comment on the status of gene therapy regulation in Japan. Interferon-beta gene therapy is expected to become widely available for clinical use in cancer patients, and this new strategy might be extended to molecular targeting therapy, or used in combination with cell therapy or other therapies.

Enhanced p53 gene transfer to human ovarian cancer cells using the cationic nonviral vector, DDC

OBJECTIVE

Previously we have formulated a new cationic liposome, DDC, composed of dioleoyltrimethylamino propane (DOTAP), 1,2-dioeoyl-3-phosphophatidylethanolamine (DOPE), and cholesterol (Chol), and it efficiently delivered plasmid DNA into ovarian cancer cells. Mutations in the p53 tumor suppressor gene are the most common molecular genetic abnormalities to be described in ovarian cancer. However, there has been so far no report of nonviral vector-mediated p53 gene deliveries in ovarian cancer. In this study, wild-type p53 DNA was transfected into the ovarian cancer cells, using the DDC as a nonviral vector and the expression and activity of p53 gene were evaluated both in vitro and in vivo.

METHOD

DDC liposomes were prepared by mixing DOTAP:DOPE:Chol in a 1:0.7:0.3 molar ratio using the extrusion method. Plasmid DNA (pp53-EGFP) and DDC complexes were transfected into ovarian carcinoma cells (OVCAR-3 cells) and gene expression was determined by reverse transcription-polymerase chain reaction and Western blot analysis. The cellular growth inhibition and apoptosis of DDC-mediated p53 transfection were assessed by trypan blue exclusion assay and annexin-V staining, respectively. The OVCAR-3 cells treated with DDC/pp53-EGFP complexes were inoculated into female balb/c nude mice and tumor growth was observed.

RESULTS

The transfection of liposome-complexed p53 gene resulted in a high level of wild-type p53 mRNA and protein expressions in OVCAR-3 cells. In vitro cell growth assay showed growth inhibition of cancer cells transfected with DDC/pp53-EGFP complexes compared with the control cells. The reestablishment of wild-type p53 function in ovarian cancer cells restored the apoptotic pathway. Following the inoculation of DDC/pp53-EGFP complexes, the volumes of tumors in nude mice were significantly reduced more than 60% compared to the control group.

CONCLUSION

The DDC-mediated p53 DNA delivery may have the potential for clinical application as nonviral vector-mediated ovarian cancer therapy due to its effective induction of apoptosis and tumor growth inhibition.

Repeated cationic multilamellar liposome-mediated gene transfer enhanced transduction efficiency against murine melanoma cell lines

We investigated whether repeated cationic multilamellar liposome-mediated gene transfers enhanced the transduction efficiency against murine melanoma cell lines and experimental subcutaneous melanoma. In the former, the murine melanoma cell line, B16F10, was transfected by our original cationic multilamellar liposomes containing pVLacZ, which express beta-galactosidase in eukaryotic cells. Cells were exposed to the liposomes in a single, double, or triple procedure during the cell logarithmic proliferative period. We then evaluated the transduction efficiency by X-gal staining and beta-galactosidase assay. The number of positive cells and level of beta-galactosidase activity were significantly increased by repeated exposures compared with a single one. Cells transfected by the fluorescently labeled cationic liposome containing pEGFP-C1 showed both an increased uptake of liposomes and an increased number of EGFP expression cells following repeated exposures. In the latter, murine subcutaneous melanomas, which were made by transplantation of B16F10 in C57BL6 mice, were transfected by same liposomes. Subcutaneous melanomas were exposed to the liposomes in a single, double, or triple procedure. We then evaluated the transduction efficiency by the beta-galactosidase assay. The level of beta-galactosidase activity was significantly increased by repeated exposures compared with a single one. The results indicate that repeated exposures to the liposomes enhanced the transduction efficiency toward murine melanoma cells and experimental subcutaneous melanoma, and may provide a basis for the repeated-exposure protocol for human trials.

Recent advances in melanoma research

Recent advancement in the research of malignant melanoma is reviewed. Among many gene alterations detected in human melanoma, defect of CDKN2A located at chromosome 9p21 seems to be most important in the earlier developmental phase, though significance of this gene in the evolution of melanoma in situ has not been confirmed yet. Deletions of PTEN/MMAC1 on 10q23.3 and AIM1 on 6q21 as well as mutations of ras gene are involved in the later progression stages of melanoma. Adhesion molecules relevant to development and progression of melanoma have been intensely investigated in recent years, revealing crucial roles of cadherins and alpha(v)beta(3) integrin in the biologic behaviors of melanoma cells. Melanoma is characterized by extremely high potential of developing metastases. Dynamic changes of matrix metalloproteinase activity during invasion and movement of melanoma cells may be a major concern in this field. Fragility of blood vessels in melanoma lesions is another important point related to hematogeneous metastases. Acral lentiginous melanoma is a unique subtype of melanoma, because, in contrast to other subtypes, ultraviolet irradiation is not a major factor in its development. Investigation of pathogenesis of acral lentiginous melanoma surely provides us with new information about mechanism of melanocyte transformation. Recent advances in the management of malignant melanoma are also briefly reviewed, such as biochemotherapy, immunotherapy, and gene therapy. Finally, the concept of molecular classification of melanoma by gene expression profile is introduced, which possibly enables us to give the tailor-made therapy for each melanoma patient in the near future.