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In principle, viral gene therapy holds significant potential for the therapy of solid cancers. However, this promise has not been fully realized and systemic administration of viruses has not proven as successful as envisioned in the clinical arena. Our research is focused on developing the next generation of efficacious viruses to specifically treat both primary cancers and a major cause of cancer lethality, metastatic tumors (that have spread from a primary site of origin to other areas in the body and are responsible for an estimated 90% of cancer deaths). We have generated a chimeric tropism‐modified type 5 and 3 adenovirus that selectively replicates in cancer cells and simultaneously produces a secreted anti‐cancer toxic cytokine, melanoma differentiation associated gene‐7/Interleukin‐24 (mda‐7/IL‐24), referred to as a Cancer Terminator Virus (CTV) (Ad.5/3‐CTV). In preclinical animal models, injection into a primary tumor causes selective cell death and therapeutic activity is also observed in non‐injected distant tumors, that is, “bystander anti‐tumor activity.” To enhance the impact and therapeutic utility of the CTV, we have pioneered an elegant approach in which viruses are encapsulated in microbubbles allowing “stealth delivery” to tumor cells that when treated with focused ultrasound causes viral release killing tumor cells through viral replication, and producing and secreting MDA‐7/IL‐24, which stimulates the immune system to attack distant cancers, inhibits tumor angiogenesis and directly promotes apoptosis in distant cancer cells. This strategy is called UTMD (ultrasound‐targeted microbubble‐destruction). This novel CTV and UTMD approach hold significant promise for the effective therapy of primary and disseminated tumors. [ABSTRACT FROM AUTHOR]

Melanoma differentiation associated gene-7/interleukin-24 (mda-7/IL-24), a cytokine belonging to the IL-10 family, displays cancer-specific apoptosis-inducing properties when delivered by a replication-incompetent adenovirus (Ad.mda-7) or as a GST-tagged recombinant protein (GST-MDA-7). Previous studies demonstrated that an adenovirus expressing M4, a truncated version of MDA-7/IL-24 containing amino acid residues 104–206, also induced similar cancer-specific apoptosis. We generated recombinant GST-M4 proteins and examined the potency of GST-MDA-7 and GST-M4 on a panel of epidermal growth factor receptor (EGFR) wild type and mutant non-small cell lung carcinoma (NSCLC) cells either as a single agent or in combination with a reversible EGFR inhibitor, Tarceva. The combination of either GST-MDA-7 or GST-M4 (∼0.1 µM) and Tarceva (10 µM), at sub-optimal apoptosis-inducing concentrations synergistically enhanced growth inhibition and apoptosis induction over that observed with either agent alone. The combination treatment also augmented inhibition of EGFR signaling, analyzed by phosphorylation of EGFR and its downstream effectors AKT and ERK1/2, over that with single-agent therapy. Tarceva enhanced GST-MDA-7 and GST-M4 toxicity in cells expressing mutated EGFR proteins that are resistant to the inhibitory effects of Tarceva. In total, these data suggest that combined treatment of NSCLC cells with an EGFR inhibitor can augment the efficacy of GST-MDA-7 and GST-M4 and that the EGFR inhibitor Tarceva may mediate this combinatorial effect by inhibiting multiple tyrosine kinases in addition to the EGFR. This approach highlights a potential new combinatorial strategy, which may prove beneficial for NSCLC patients with acquired resistance to EGFR inhibitors. J. Cell. Physiol. 215: 827–836, 2008. © 2008 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Activation of the epidermal growth factor receptor (EGFR) contributes to the pathogenesis of non-small-cell lung carcinomas (NSCLC) and gefitinib, a selective reversible EGFR inhibitor, is effective in treating patients with NSCLC. However, clinical resistance to gefitinib is a frequent occurrence highlighting the need for improved therapeutic strategies. Melanoma differentiation associated gene-7 (mda-7)/Interleukin-24 (IL-24) (mda-7/IL-24) displays cancer-selective apoptosis induction when delivered via a replication-incompetent adenovirus (Ad.mda-7). In this study, the effect of Ad.mda-7 infection, either alone or in combination with gefitinib, was analyzed in a panel of NSCLC cell lines carrying wild-type EGFR (H-460 and H-2030) or mutant EGFR (H-1650 and H-1975). While H-2030 and H-1650 cells were sensitive, H-460 and H-1975 cells were resistance to growth inhibition by Ad.mda-7, which was reversed by the combination of Ad.mda-7 and gefitinib. This combination increased MDA-7/IL-24 and downstream effector double-stranded RNA-activated protein kinase (PKR) protein expression, promoting apoptosis induction of NSCLC cells. Inhibition of PKR significantly inhibited apoptosis induction by Ad.mda-7 when administered alone but not when used in combination with gefitinib. The combination treatment also augmented inhibition of EGFR signaling. Our findings indicate that a combinatorial treatment with Ad.mda-7 and gefitinib may provide benefit in the treatment of NSCLC, especially in patients displaying resistance to clinically used EGFR inhibitors. J. Cell. Physiol. 210: 549–559, 2007. © 2006 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Primary, glioblastoma, and secondary brain tumors, from metastases outside the brain, are among the most aggressive and therapeutically resistant cancers. A physiological barrier protecting the brain, the blood–brain barrier (BBB), functions as a deterrent to effective therapies. To enhance cancer therapy, we developed a cancer terminator virus (CTV), a unique tropism‐modified adenovirus consisting of serotype 3 fiber knob on an otherwise Ad5 capsid that replicates in a cancer‐selective manner and simultaneously produces a potent therapeutic cytokine, melanoma differentiation‐associated gene‐7/interleukin‐24 (MDA‐7/IL‐24). A limitation of the CTV and most other viruses, including adenoviruses, is an inability to deliver systemically to treat brain tumors because of the BBB, nonspecific virus trapping, and immune clearance. These obstacles to effective viral therapy of brain cancer have now been overcome using focused ultrasound with a dual microbubble treatment, the focused ultrasound‐double microbubble (FUS‐DMB) approach. Proof‐of‐principle is now provided indicating that the BBB can be safely and transiently opened, and the CTV can then be administered in a second set of complement‐treated microbubbles and released in the brain using focused ultrasound. Moreover, the FUS‐DMB can be used to deliver the CTV multiple times in animals with glioblastoma  growing in their brain thereby resulting in a further enhancement in survival. This strategy permits efficient therapy of primary and secondary brain tumors enhancing animal survival without promoting harmful toxic or behavioral side effects. Additionally, when combined with a standard of care therapy, Temozolomide, a further increase in survival is achieved. The FUS‐DMB approach with the CTV highlights a noninvasive strategy to treat brain cancers without surgery. This innovative delivery scheme combined with the therapeutic efficacy of the CTV provides a novel potential translational therapeutic approach for brain cancers. [ABSTRACT FROM AUTHOR]

Neuroblastoma (NB) is a common solid extracranial tumor developing in pediatric populations. NB can spontaneously regress or grow and metastasize displaying resistance to therapy. This tumor is derived from primitive cells, mainly those of the neural crest, in the sympathetic nervous system and usually develops in the adrenal medulla and paraspinal ganglia. Our understanding of the molecular characteristics of human NBs continues to advance documenting abnormalities at the genome, epigenome, and transcriptome levels. The high‐risk tumors have MYCN oncogene amplification, and the MYCN transcriptional regulator encoded by the MYCN oncogene is highly expressed in the neural crest. Studies on the biology of NB has enabled a more precise risk stratification strategy and a concomitant reduction in the required treatment in an expanding number of cases worldwide. However, newer treatment strategies are mandated to improve outcomes in pediatric patients who are at high‐risk and display relapse. To improve outcomes and survival rates in such high‐risk patients, it is necessary to use a multicomponent therapeutic approach. Accuracy in clinical staging of the disease and assessment of the associated risks based on biological, clinical, surgical, and pathological criteria are of paramount importance for prognosis and to effectively plan therapeutic approaches. This review discusses the staging of NB and the biological and genetic features of the disease and several current therapies including targeted delivery of chemotherapy, novel radiation therapy, and immunotherapy for NB. [ABSTRACT FROM AUTHOR]

As a strategy to identify gene expression changes affected by human polynucleotide phosphorylase ( hPNPaseold-35), we performed gene expression analysis of HeLa cells in which hPNPaseold-35 was overexpressed. The observed changes were then compared to those of HO-1 melanoma cells in which hPNPaseold-35 was stably knocked down. Through this analysis, 90 transcripts, which positively or negatively correlated with hPNPaseold-35 expression, were identified. The majority of these genes were associated with cell communication, cell cycle, and chromosomal organization gene ontology categories. For a number of these genes, the positive or negative correlations with hPNPaseold-35 expression were consistent with transcriptional data extracted from the TCGA (The Cancer Genome Atlas) expression datasets for colon adenocarcinoma (COAD), skin cutaneous melanoma (SKCM), ovarian serous cyst adenocarcinoma (OV), and prostate adenocarcinoma (PRAD). Further analysis comparing the gene expression changes between Ad. hPNPaseold-35 infected HO-1 melanoma cells and HeLa cells overexpressing hPNPaseold-35 under the control of a doxycycline-inducible promoter, revealed global changes in genes involved in cell cycle and mitosis. Overall, this study provides further evidence that hPNPaseold-35 is associated with global changes in cell cycle-associated genes and identifies potential gene targets for future investigation. J. Cell. Physiol. 229: 1952-1962, 2014. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Retinoic acid inducible gene-I (RIG-I) functions as the first line of defense against viral infection by sensing dsRNA and inducing type I interferon (IFN) production. The expression of RIG-I itself is induced by IFN-α/β and dsRNA. To comprehend the molecular mechanism of expression regulation, we cloned the RIG-I promoter and analyzed its activity upon IFN-β and dsRNA treatment. Under basal condition, RIG-I mRNA level and promoter activity were significantly higher in normal cells versus their tumor counterparts. In both normal and cancer cells, RIG-I expression was induced by IFN-β and dsRNA. A single IRF-1 binding site in the proximal promoter functioned as a crucial regulator of basal, IFN-β- and dsRNA-mediated induction of the RIG-I promoter. IFN-β and dsRNA treatment increased IRF-1 binding to the RIG-I promoter. IRF-1 expression was also higher in normal cells than in cancer cells and it was induced by IFN-β with similar kinetics as RIG-I. These results confirm that by controlling RIG-I expression, IRF-1 plays an essential role in anti-viral immunity. IRF-1 is a tumor suppressor and the expression profile of RIG-I together with its regulation by IRF-1 and the presence of a caspase-recruitment domain in RIG-I suggest that RIG-I might also possess tumor suppressor properties. J. Cell. Physiol. 213: 502–510, 2007. © 2007 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Gene therapy, which involves replacement of a defective gene with a functional, healthy copy of that gene, is a potentially beneficial cancer treatment approach particularly over chemotherapy, which often lacks selectivity and can cause non-specific toxicity. Despite significant progress pre-clinically with respect to both enhanced targeting and expression in a tumor-selective manner several hurdles still prevent success in the clinic, including non-specific expression, low-efficiency delivery and biosafety. Various innovative genetic approaches are under development to reconstruct vectors/transgenes to make them safer and more effective. Utilizing cutting-edge delivery technologies, gene expression can now be targeted in a tissue- and organ-specific manner. With these advances, gene therapy is poised to become amenable for routine cancer therapy with potential to elevate this methodology as a first line therapy for neoplastic diseases. This review discusses recent advances in gene therapy and their impact on a pre-clinical and clinical level. J. Cell. Physiol. 230: 259-271, 2015. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]