Anti-influenza-virus activity of total alkaloids from Commelina communis L.

The antiviral activity of total alkaloids from Commelina communis L. (TAC) against influenza virus A/PR/8/34 (H1N1) was investigated in vitro and in vivo. TAC exhibited an inhibitory action on the growth of influenza virus in Madin-Darby canine kidney cells when added before or after viral infection. In mice infected with influenza virus, orally administered TAC at 8, 16 or 32 mg/kg per day for 6 days significantly increased the survival rate, prolonged the mean survival time and reduced the viral titers in the lung and the lung index, compared with that of the untreated virus control. The results obtained suggest that TAC has a pronounced protective effect against infection by influenza A virus.

Combination of VEGF(165)/Angiopoietin-1 gene and endothelial progenitor cells for therapeutic neovascularization.

Previous studies have established that vascular endothelial growth factor (VEGF), Angiopoietin-1 (Ang1) and endothelial progenitor cells (EPCs) play important roles in neovascularization, suggesting that combination of them would be a promising therapy for ischemic diseases. So we constructed the adeno-associated virus-2 (AAV-2) vectors simultaneously encoding human VEGF(165) and Ang1 (AAV-Ang1/VEGF), and investigated the combination therapeutic effect of AAV-Ang1/VEGF with EPCs in a rabbit ischemic hindlimb model. In the present study we found that AAV-Ang1/VEGF could successfully and efficiently transfer VEGF(165) and Ang1 gene into bone marrow derived EPCs for gene therapy. Combined administration of AAV-Ang1/VEGF with EPCs had higher blood flow recovery, cellularity, capillary density and smooth muscle alpha-actin positive vessel density than administration of either of them alone. Furthermore, the strategy of pre-intramuscular injection of AAV-Ang1/VEGF followed by EPCs transplantation had a higher therapeutic effect than the strategy of transplantation of AAV-Ang1/VEGF transduced EPCs. It seemed that the former strategy may be a promising therapy for ischemic diseases.

[Death mode of Hep-3B and A549 tumor cells induced by bluetongue virus strain HbC3].

OBJECTIVE: To study the death mode of human hepatocellular carcinoma Hep-3B cells and human lung adenocarcinoma A549 cells induced by bluetongue virus strain HbC3 (BTV-HbC3) and the mechanism of its action. METHODS: BTV-HbC3 was used to infect the tumor cells, and the cytopathic effects (CPE) was observed. TUNEL staining was used to detect the apoptosis of tumor cells induced by BTV-HbC3. The changes of endoplasmic reticulum and nuclei treated with BTV-HbC3 were further examined by laser scanning confocal microscopy. The activities of caspase-3/7, caspase-8 and caspase-9 were determined by fluorescence analysis. RESULTS: Hep-3B cells were sensitive to BTV-HbC3. Lots of early apoptotic cells were found by TUNEL staining. The laser scanning confocal microscopic examination showed characteristics of apoptosis, such as pyknotic nuclei, margination of nuclear chromatin and vacuolization of endoplasmic reticulumin in Hep-3B cells exposed to BTV-HbC3. The activity of caspase-3/7 was increased, but the activity changes of caspase-8 and caspase-9 were not found. A549 cells were sensitive to BTV-HbC3 too. But no apoptotic cells were observed by TUNEL staining. The results of laser scanning confocal microscopy showed marked vacuolization of endoplasmic reticulum, but chromatin margination was not found after A549 cells was exposed to BTV-HbC3. The activity of caspase-3/7 and caspase-9 was increased, but the activity of caspase-8 was not changed. CONCLUSION: BTV-HbC3 induces apoptosis of Hep-3B tumor cells mainly through endoplasmic reticulum signal transduction pathway, and the features of cell death in A549 cells could be described as paraptosis.

Tumor-targeted therapy with a conditionally replicating mutant of HSV-1 induces regression of xenografted human hepatomas.

The selectively oncolytic effects of mtHSV, a HSV icp34.5 mutant with lacz gene insertion, on several tumor cells in vitro and its antitumor effects by the intratumoral (IT) route to nude mice loaded the human hepatoma xenografts were explored. The mtHSV could conditionally replicate in and lyse Hep-3B (human hepatoma cells), Hep-2 (human larynx cancer cells) and SPC-A1 (human lung cancer cells), but not MRC-5 (human fibroblast cells). The 125 nude mice loaded with Hep-3B were randomly divided into five treatment groups and given three IT injections with three different dose of the mtHSV, adriamycin (ADM), or vehicle (supernatant of non-infected Vero cells). Significant tumor growth inhibition (30%-70%) was seen in the nude mice treated IT with mtHSV, whereas tumors treated IT with Vero supernatant displayed rapid tumor growth. The results of regular and biochemical blood examination, systemic necropsy and pathological slices showed that mtHSV almost has no side effect on treated mice. RT-PCR results revealed that the replication of mtHSV was exclusively confined to the treated tumors, but not to other organs. Our results provide further preclinical evidence that mtHSV may be used as an oncolytic agent for cancer therapy.

Conditional replication of a recombinant adenovirus studied using neomycin as a selective marker.

An E1B-defective adenovirus, named r2/Ad carrying the neo expression cassette, was constructed by homologous recombination. The construction, selection (using neomycin as a selective marker), and propagation of the recombinant virus was performed in human embryonic kidney 293 cells (HEK 293). An in vitro study demonstrated that this recombinant virus has the ability to replicate in and lyse some p53-deficient human tumor cells such as human glioma tumor cells (U251) and human bladder cells (EJ), but not in some cells with functional p53, such as human adenocarcinoma cells (A549) and human fibroblast cells (MRC-5). Also, based on the cytopathic effect (CPE), it was demonstrated, under identical conditions, that the U251 cells were more sensitive to r2/Ad replication than the EJ cells. In this paper, we report that r2/Ad could be very useful in studying the in vitro selective replication of E1B-defective adenovirus and has great potential in cancer gene therapy.

Effect of total alkaloids from Commelina communis L. on lung damage by influenza virus infection.

Whether administration of total alkaloids from Commelina communis L. (TAC) reduces lung damage in influenza virus-infected mice was investigated. Compared with untreated mice, significantly less severe damage was found in the lungs of mice administered TAC at 8 mg/kg per day for 6 days. TAC significantly decreased viral loads in the lungs. The concentrations of IFN-γ in the serum of TAC-treated mice were significantly lower than those of virus control mice at 4 and 6 days post-infection. The results indicate that TAC imparted partial protection to the mice by reducing pulmonary viral loads and limiting lesions in the lungs.

Selective in vitro cytotoxic effect of human cancer cells by bluetongue virus-10.

Bluetongue viruses (BTVs) infect primarily domestic cattle and wild ruminants but have never been shown to infect normal human cells. Thus, humans are sero-negative towards BTVs. The selective and differential effects of BTV serotype 10 (BTV-10) infection were investigated with five cell lines including primary human embryo lung fibroblast (HEL) and primary murine embryos fibroblast(MEF), human hepatic carcinoma 3B cell line (Hep-3B), human lung carcinoma cell line (A549) and mouse fibroblast cell line (NIH 3T3). In this study, comparative analyses of differential cytopathic effects (CPEs), survival rates using different Multiplicities of Infection (MOI), ultra-structural changes by transmission electron microscopy, and the preferential cell cycle changes of infected cells by flow cytometry were made among these cells. Detection of the presence of BTV genome and kinetic analysis of virus titers in TCID50 were also made. We provided the first analytical demonstration and evidence that BTV-10 could selectively infect and degrade human cancer cells but not cultured primary normal cells. No CPE or viral mRNAs could be detected within these normal cells, while various degrees of CPE could be found in Hep-3B and A549, as well as in NIH 3T3 under similar conditions. Before death, BTV-infected human cancer cells were directly arrested in the sub-G1 phase and the diversity of BTV infection as shown by the MTT method had significant difference (F = 95.635, p < 0.01). Above results suggested that this viral dose-dependent cytotoxic effect is caused by both effective virion amplification and induced apoptosis. Cellular distinctive transformation status may contribute to the selectivity. Thus, selective degradation of human cancer cells but not normal diploid cells by the newly discovered oncolytic potential of BTV would provide a very attractive approach for cancer therapy in the future.

Adeno-associated virus vectors simultaneously encoding VEGF and angiopoietin-1 enhances neovascularization in ischemic rabbit hind-limbs.

AIM: Angiopoietin-1 (Ang1) and vascular endothelial growth factor A (VEGF) play important roles in vascular formation and maturation, suggesting a combination of these 2 would be a promising therapy for ischemic diseases. So we constructed an adeno-associated virus (AAV) vector, simultaneously encoding human VEGF(165) and Ang1 (AAV-VEGF/Ang1), and investigated its therapeutic effect in a rabbit ischemic hind-limb model. METHODS: Four experimental groups were used to prepare the rabbit ischemic hind-limb model following AAV vectors intramuscular administration as follows: PBS (phosphate buffered solution), AAV-VEGF, AAV-Ang1, AAV-VEGF/Ang1. RESULTS: Eight weeks after administration, human VEGF(165) and Ang1 were detected by RT-PCR, Western blotting and histochemical staining methods in AAV-VEGF/Ang1 transduced muscles. Group AAV-VEGF/Ang1 showed a significantly increased blood-flow recovery in ischemic hind-limbs compared with the other groups. Histological staining for alkaline phosphatase showed that capillary density of group AAV-VEGF/Ang1 or AAV-VEGF was significantly higher than that of group PBS or AAV-Ang1. Histological immunostaining for smooth muscle alpha-actin (alpha-SMA) revealed that group AAV-VEGF/Ang1 had the highest density of alpha-SMA-positive vessels compared with the other groups. Vascular leakage, one of the major adverse effects induced by VEGF, was very severe in group AAV-VEGF, but the permeability was obviously reduced when VEGF was co-expressed with Ang1 in group AAV-VEGF/Ang1. CONCLUSION: AAV vectors can simultaneously encode 2 proteins which can be efficiently and stably co-expressed in transduced tissues. AAV-mediated VEGF and Ang1 gene transfer enhances neovascularization, prevents capillary leakage, and improves blood flow in a rabbit hind-limb ischemic model. These findings suggest that intramuscular administration of AAV-VEGF/Ang1 may be useful in the treatment of ischemic diseases.

Selective cytolysis of tumor cells by mumps virus S79.

We studied the sensitivity of several human cancer cell strains (HeLa, HT1080, SPC-A1, and ACHN) and normal cell strains (MRC-5 and Wish) to mumps virus (MuV) S79, a live attenuated vaccine strain. These cells exhibited a differential sensitivity to infection with MuV, and the susceptible sequences were ACHN > HeLa > HT1080 > SPC-A1 > Wish > MRC-5. In experiments in vivo, nude mice with HT1080 fibrosarcoma xenografts were randomly divided into three groups for intratumoral treatment with MuVS79, UV-inactivated MuVS79, and PBS. At 10(7) PFU, live MuVS79 injection caused in 7 of 9 mice complete regression by day 15 while rapid tumor growth occurred in all 9 mice treated with PBS. Rapid tumor progression also occurred in all 8 mice treated with UV-inactivated virus; however, tumor growth was delayed in the logarithmic phase relative to the PBS-treated tumors.