Regulation of epidermal growth factor receptor signaling by plasmid-based microRNA-7 inhibits human malignant gliomas growth and metastasis in vivo.

MicroRNAs are endogenous, non-coding RNAs of approximately 20-22 nucleotides that regulate genes expression by binding to the 3' untranslated region (UTR) of targets mRNAs and play critical roles in cancer pathways. Malignant glioma is the most common and highly lethal central nervous system tumor for which little effective treatment is available over several decades. The purpose of this study was to explore the therapeutic potential of plasmid-based microRNA-7 (miR-7) for gliomas in vivo. Enhancing miR-7 levels in vitro could significantly induce cell apoptosis, and inhibit cell proliferation, cell migration and invasion. Western blotting analysis was performed, which indicated that miR-7 directly inhibited epidermal growth factor receptor (EGFR) and further antagonized the downstream protein kinases including ERK, Akt and Stat3. Furthermore, systemic administration of miR-7 encapsulated in cationic liposome resulted in glioma xenografts growth arrest and the metastatic nodules decrease effectively in a sequence-specific manner. In this study, miR-7 was applied in glioma treatment for the first time in vivo. Our findings suggested that the plasmid-mediated gene therapy with miR-7 appeared to be a promising candidate for the development of new antitumor and anti-metastasis treatment for human glioma.

Dynamic isomer shift in charge-ordering manganite Y(0.5)Ca(0.5)MnO(3): Mössbauer spectroscopy study.

We report the Mössbauer spectroscopy study on Fe-doped charge-ordering manganite Y(0.5)Ca(0.5)MnO(3). The dynamic isomer shift is observed for charge-ordering manganite, and its origin may be due to strong Jahn-Teller distortions in Y(0.5)Ca(0.5)MnO(3), causing electron-phonon coupling. The evolution of Mössbauer spectroscopy as a function of temperature shows two different phases with significantly different quadrupole splitting values below the charge-ordering transition temperature. This confirms that there exist two different Mn sites (i.e., Mn(3+) and Mn(4+) ions), which can be identified by the microscopic method of Mössbauer spectroscopy.

Tumor-specific oncolytic adenoviruses expressing granulocyte macrophage colony-stimulating factor or anti-CTLA4 antibody for the treatment of cancers.

The purpose of this study was to examine the tumor specificity, cytotoxicity and the antitumor activity of two conditionally replicating oncolytic adenoviruses, SKL001 and SKL002, which expressed granulocyte macrophage colony-stimulating factor (GM-CSF) or anti-cytotoxic T lymphocyte-associated antigen-4 (CTLA4) antibody, respectively, and determine their antitumor efficacy in A549 lung tumor model, B16F10 mouse melanoma tumor model and CMT-64 mouse small lung carcinoma tumor model. Virus yield and cytotoxicity were used to determine tumor specificity and virus replication-mediated cytotoxicity of SKL001 and SKL002 in a panel of human tumor cell lines and primary cells in vitro. Two subcutaneous (s.c.) tumor nexograft tumor models were used to assess their antitumor activity. Under the control of the E2F promoter, the expression of E1a genes appeared only in tumor cells, whereas the wild-type Ad5 expressed its E1a genes in both tumor cells and normal cells. GM-CSF and anti-CTLA4 production were significantly higher in tumor cells than normal cells. SKL001 and SKL002 replicated in Rb-defective cell lines as efficiently as wild-type adenovirus but produced 100-fold less virus in normal human cells. SKL001 and SKL002 was up to 1000-fold more cytotoxic in Rb pathway-defective human tumor cells in comparison with normal human cells. Antitumor activity of SKL001 and SKL002 following intravenous administration was shown in a human lung A549 s.c. xenograft tumor model and mouse B16F10 melanoma tumor model when compared with phosphate-buffered saline treatment. In immune-competent mice, the addition of GM-CSF produced a stronger antitumor activity and induced a higher number of mature dendritic cells and macrophages, whereas additive antitumor activity was observed in the group when SKL001 and SKL002 were combined. In vitro and in vivo studies showed the selective replication, cytotoxicity, gene production and antitumor efficacy of SKL001 and SKL002 in human tumor model, suggesting a potential utility of this oncolytic agent for the treatment of human cancer. Further studies are warranted to show the role of human GM-CSF and anti-CTLA4 antibody in the antitumor efficacy of these two oncolytic viruses.

IL15 combined with Caspy2 provides enhanced therapeutic efficiency against murine malignant neoplasm growth and metastasis.

Interleukin-15 (IL15) is a potential immunotherapeutic treatment for cancer. Caspy2 is an active zebra caspase for inducing apoptosis and immune response in murine tumors. In this study, we aim to evaluate the potential of gene therapy using IL15 and Caspy2 against the murine tumors. Plasmid expressing both Caspy2 and IL15 genes was constructed, encapsulated in DOTAP/cholesterol cationic liposome and injected intratumorally into the mice bearing CT26, B16-F10 and 4T1 carcinoma. We found that coexpression of IL15 and Caspy2 could significant inhibit tumor growth and prolong survival of the mice bearing CT26 or B16F10 tumor. A significant reduction in spontaneous lung metastasis was observed in the 4T1 tumor model. In CT26 model, the mice treated with IL15 and Caspy2 acquired a long-time protective immunity against the parental tumor cell rechallenge. Cytotoxic T lymphocytes and terminal deoxynucleotidyltransferase-mediated nick end labelling assays showed that the combination of capsy2 and IL15 could enhance both the apoptosis and immune response induction, which may account for its extraordinary antitumor effect. Furthermore, we showed that the observed tumor suppression by IL15 and Caspy2 concurred with the Caspy2-mediated downregulation of IL10 and upregulation of interferon-γ and tumor necrosis factor-α. Our results therefore suggested that the combination regimen might be a novel and effective strategy for cancer treatment.

Synthesis and field electron emission properties of hybrid carbon nanotubes and nanoparticles.

Hybrid ZnO-carbon nanotubes as well as nanodiamond-carbon nanotubes were synthesized via a straightforward process of plasma enhanced chemical vapor deposition. For the former, ZnO nanoparticles were instantly coated on the tube surface in the final growing process of carbon nanotubes, while for the latter diamond nanoparticles were grown using pretreatment of a silicon substrate with Ni(NO(3))(2)·6H(2)O/Mg(NO(3))(2)·6H(2)O alcohol solution prior to deposition and a high H(2)/CH(4) gas flow ratio in the deposition process. The morphology and microstructure of the obtained hybrid materials were characterized by transmission electron microscopy. Both hybrid ZnO-carbon nanotubes and nanodiamond-carbon nanotubes exhibited excellent field emission properties.

[The recombinant vaccinia viruses expressing HPV type 16 wild or mutant E7 protein elicit immunity against tumor cells in mice].

OBJECTIVE: To select mutants of HPV 16 E7 suitable for vaccine development. METHODS: Several recombinant vaccinia viruses (VwE7, VmE7-1, and VmE7-2) expressing wild E7 or its mutants, ME7-1 (24G26G) and ME7-2 (24G26G91G) respectively, were employed to study their antigenicity and anti tumor activity. RESULTS: Both VmE7-1 and VwE7 could elicit cytotoxic T lymphocytes (CTL)and protect mice against tumor cells challenge, but VmE7-2 could not induce the immune reactions compared with VmE7-1 and VwE7. CONCLUSIONS: It suggested that ME7-1 could be used to develop a therapeutic vaccine for cervical cancer.