Non-covalent inhibitors of thioredoxin glutathione reductase with schistosomicidal activity in vivo.

Only praziquantel is available for treating schistosomiasis, a disease affecting more than 200 million people. Praziquantel-resistant worms have been selected for in the lab and low cure rates from mass drug administration programs suggest that resistance is evolving in the field. Thioredoxin glutathione reductase (TGR) is essential for schistosome survival and a validated drug target. TGR inhibitors identified to date are irreversible and/or covalent inhibitors with unacceptable off-target effects. In this work, we identify noncovalent TGR inhibitors with efficacy against schistosome infections in mice, meeting the criteria for lead progression indicated by WHO. Comparisons with previous in vivo studies with praziquantel suggests that these inhibitors outperform the drug of choice for schistosomiasis against juvenile worms.

Nonviral Delivery of GRIM-19 Gene Inhibits Tumor Growth with Reduced Local and Systemic Complications.

Chemotherapy causes inflammation, which promotes cancer development and results in complications such as hemorrhages and thrombosis. Development of new therapeutic strategies to limit inflammatory responses will potentially reduce these side effects in cancer patients. Gene therapy is an attractive cancer treatment because of its high specificity and limited side effects. A tumor suppressor gene associated with retinoid-interferon-induced mortality-19 (GRIM-19) was delivered by an amphiphilic copolymer poly(ɛ-caprolactone) and ethanolamine-functionalized poly (glycidyl methacrylate) (PCG). The transfection outcome of PCG/pGRIM-19 complexes was studied both in vitro and in vivo. The antitumor therapeutic effects were evaluated in a well-vascularized Neuro-2a neuroblastoma tumor mouse model in comparison with that of cisplatin. The PCG/pGRIM-19 nanocomplex showed high transfection efficiency and low toxicity. In vitro transfection of PCG/pGRIM-19 in Neuro-2a cells reduced the expression levels of Cyclin D1, BCL-2, and MMPs 2 and 9, and inhibited cell proliferation, migration, and stimulated apoptosis. In vivo experiments indicated that PCG/pGRIM-19 therapy downregulated signal transducer activator of transcription 3, nuclear factor-κB, and MMP9 expression in tumor tissues. Compared with cisplatin treatment, gene therapy with PCG/pGRIM-19 significantly inhibited local complications of intratumor hemorrhages, and systemic complications such as anemia and pulmonary embolism, thereby effectively prolonged mouse survival. Our results highlight the potential of PCG/pGRIM-19 gene therapy in reducing tumor burden and complications, providing novel strategies to enhance clinical cancer therapy.

Antitumor activity of iNGR-GRIM-19 in colorectal cancer.

BACKGROUND: Gene associated with retinoid-interferon induced mortality-19 (GRIM-19) plays crucial roles in carcinogenesis. OBJECTIVE: To explore the antitumor activity of internalizing NGR (iNGR) gene associated with GRIM-19 in colorectal cancer. METHODS: Cells were incubated with fluorescein isothiocyanate-labeled fusion proteins followed by fluorescence microscopic analysis. Cell proliferation was determined by MTT assay. Cell cycle was analyzed by flow cytometric analysis. Cell migration and invasion capacity were evaluated by wound scratch and Transwell assays, respectively. Apoptosis was measured by Annexin V/PI staining and TUNEL assay. Gene expressions were determined by RT-PCR and Western blotting. Nude mice bearing colorectal cancer received vehicle, GRIM-19, or iNGR-GRIM-19 fusion protein injection, and the in vivo antitumor capacity of the fusion proteins was examined. RESULTS: iNGR-GRIM-19 was specifically taken up by human colorectal cancer Colo205 cells, but not corneal epithelial (HCEpic) cells, whereas GRIM-19 was not internalized by either cell type. Unlike GRIM-19, incubation with iNGR-GRIM-19 dose-dependently inhibited proliferation, induced G1 phase arrest, suppressed cell migration and invasion, and caused apoptosis in Colo205 cells. Additionally, injection of iNGR-GRIM-19 extended the lifespan of colorectal cancer-bearing nude mice and reduced in vivo tumor growth as compared with vehicle or GRIM-19 treatment. iNGR-GRIM-19 was localized only in the tumor mass, without affecting other tissues, such as liver or kidney. iNGR-GRIM-19 injection led to G1 phase arrest and induced cell apoptosis in xenografted colorectal cancer tissues. CONCLUSIONS: iNGR-GRIM-19 has an efficient antitumor activity in vitro and in vivo, and might be a promising agent for the treatment of colorectal cancer.

Enhanced antitumor effect of cisplatin in human oral squamous cell carcinoma cells by tumor suppressor GRIM­19.

Gene associated with retinoid­interferon­induced mortality 19 (GRIM­19) is a novel candidate tumor suppressor gene located on the human chromosome 19p13.1 region. Our previous study demonstrated that the upregulation of GRIM­19 in human oral squamous cell carcinoma (OSCC) cells significantly inhibited tumor cell growth in vitro and in vivo. In the present study, the combined effects of cationic liposome (LP)­mediated GRIM­19 gene (LP­pGRIM­19) and the low­dose chemotherapeutic drug, cisplatin (CDDP), on tumor cell growth in vitro and in vivo were examined, and the molecular mechanism of their mutual action was investigated by cell proliferation, colony formation, apoptosis, migration, invasion and western blotting assays in vitro, and a node nude tumor model. It was demonstrated that cationic LP­pGRIM­19 gene therapy sensitized the response of breast cancer cells to CDDP, and that LP­pGRIM­19 in combination with CDDP significantly induced apoptosis and inhibited proliferation, colony formation, migration and invasion of the cells, compared with CDDP treatment alone. In addition, systemic treatment with a combination of intravenous injection of LP­pGRIM­19 and intraperitoneal injection of low­dose CDDP into subcutaneous HSC3 human OSCC xenograft mice resulted in a significant inhibition of tumor growth (P<0.05). Further investigations indicated that the enhancement of CPPP­mediated antitumor effects by GRIM­19 may be associated with the upregulation of phosphorylated p53 and the downregulation of B cell lymphoma­2, cyclin D1, vascular endothelial growth factor, matrix metalloproteinase (MMP)­2 and MMP­9, the proteins of which are involved in the activation of signal transducer and activator of transcription 3. The results of the present study suggested that the combination of GRIM­19 gene therapy with low­dose CPPP­based chemotherapy may be a potent therapeutic strategy for the treatment of OSCC.

Gene gun bombardment with DNA-coated golden particles enhanced the protective effect of a DNA vaccine based on thioredoxin glutathione reductase of Schistosoma japonicum.

Schistosomiasis, caused by infection with Schistosoma species, remains an important parasitic zoonosis. Thioredoxin glutathione reductase of Schistosoma japonicum (SjTGR) plays an important role in the development of the parasite and for its survival. Here we present a recombinant plasmid DNA vaccine, pVAX1/SjTGR, to estimate its protection against S. japonicum in BALB/c mice. The DNA vaccine administrated by particle bombardment induced higher protection than by intramuscular injection. All animals vaccinated with pVAX1/SjTGR developed significant specific anti-SjTGR antibodies than control groups. Moreover, animals immunized by gene gun exhibited a splenocyte proliferative response, with an increase in IFN- γ and IL-4. The recombinant plasmid administrated by gene gun achieved a medium protective efficacy of 27.83-38.83% (P < 0.01) of worm reduction and 40.38-44.51% (P < 0.01) of liver egg count reduction. It suggests that different modes of administering a DNA vaccine can influence the protective efficacy induced by the vaccine. Interestingly, from the enzymatic activity results, we found that worms obtained from pVAX1/SjTGR-vaccinated animals expressed lower enzymatic activity than the control group and the antibodies weakened the enzymatic activity of SjTGR in vitro, too. It implies that the high-level antibodies may contribute to the protective effects.