Antitumor effect of a dual cancer-specific oncolytic adenovirus on prostate cancer PC-3 cells.

PURPOSE: Apoptin can specifically kill cancer cells but has no toxicity to normal cells. Human telomerase reverse transcriptase (hTERT) acts as a tumor-specific promoter, triggering certain genes to replicate or express only in tumor cells, conferring specific replication and killing abilities. This study aimed to investigate the anticancer potential of the recombinant adenovirus Ad-apoptin-hTERTp-E1a (Ad-VT) in prostate cancer. METHODS: The pGL4.51 plasmid was used to transfect PC-3 cells to construct tumor cells stably expressing luciferase (PC-3-luc). Crystal violet staining and MTS assays determined the ability of Ad-VT to inhibit cell proliferation. Ad-VT-induced apoptosis of PC-3-luc cells was detected using Hoechst, Annexin V, JC-1 staining, and caspases activity analysis. PC-3-luc cells invasion and migration were detected using cell-scratch and Transwell assays. In vivo tumor inhibition was detected using imaging techniques. RESULTS: Crystal violet staining and MTS results showed that the proliferation ability of PC-3-luc cells decreased significantly. Hoechst, JC-1, and Annexin V experiments demonstrated that Ad-VT mainly induced apoptosis to inhibit PC-3-luc cell proliferation. Ad-VT could significantly inhibit the migration and invasion of PC-3-luc cells over a short period of time. In vivo, Ad-VT could effectively inhibit tumor growth and prolong survival of the mice. CONCLUSIONS: The recombinant adenovirus, comprising the apoptin protein and the hTERTp promoter, was able to inhibit the growth of prostate cancer PC-3 cells and promote their apoptosis.

SIV-Specific Antibodies are Elicited by a Recombinant Fowlpox Virus Co-expressing SIV Gag and envT.

Given the failures of past HIV-1 vaccine clinical trials, potential HIV-1 vaccine candidates should be rigorously screened in preclinical models including simian immunodeficiency virus (SIV) primate models and small animal models. In this study, we tested the immunogenicity of a recombinant fowlpox virus (rFPV) expressing the SIV gag and SIV envT (rFPVsg-se) proteins in BALB/c mice, to establish a foundation for further development. rFPVsg-se was constructed through homologous recombination techniques and purified through plaque screening assays using enhanced green fluorescent protein as the reporter gene. The integration, transcription, and translation of the SIV genes were measured by PCR (genomic DNA), RT-PCR (RNA), Western-blot, respectively. The levels of SIV-specific antibodies were assessed by ELISA following a single immunization (n = 18/group) or a prime-boost strategy (n = 24/group) with rFPVsg-se and compared to FPV and PBS controls. Residual virus was measured in distant organs following immunization using PCR. SIV-specific IgG titers against gag and gp120 were detected following single vaccination and the prime-boost. As expected the titers were higher following the prime-boost approach. The levels of Gag- and gp120-specific antibodies were significantly higher than controls (p < 0.01) 14 days after the booster immunization. Residual rFPVSg-Se was detected in the muscle at the site of injection, but not in distant organs, from day 1-7 post immunization. In summary, rFPVsg-se induced high levels of SIV-specific antibodies suggesting it may be a viable candidate for further development.

Construction of an attenuated goatpox virus AV41 strain by deleting the TK gene and ORF8-18.

Goatpox virus (GTPV) is prevalent in goats and is associated with high mortality. This virus causes fever, skin nodules, lesions in the respiratory and lymph node enlargement. Considering the safety risks and side effects of vaccination with attenuated live GPTV vaccine strain AV41, an attenuated goatpox virus (GTPV-TK-ORF), was constructed by deleting non-essential gene fragments without affecting replication and related to the virulence and immunomodulatory functions of the goatpox virus AV41 strain (GTPV-AV41) using homologous recombination and the Cre (Cyclization Recombination Enzyme)/Loxp system. The results of both in vivo and in vitro experiments demonstrated that GTPV-TK-ORF was safer than wild type GTPV-AV41, possessed satisfactory immunogenicity, and could protect goats from a virulent GTPV-AV40 infection. Moreover, the IFN-γ, GTPV-specific antibody, and neutralizing antibody levels in the GTPV-TK-ORF-immunized group were significantly higher than that in the normal saline control group following immunization (P < 0.01). Thus, GTPV-TK-ORF may be used as a potential novel vaccine and viral vector with good safety and immunogenicity.

Inhibitory effect of recombinant oncolytic adenovirus on luciferase-labeled and non-labeled human lung cancerA549 cells / 中国肿瘤生物治疗杂志

@# Objective: To investigate the inhibitory effect of recombinant oncolytic adenovirusAd-Apoptin-hTERTp-E1A(ATV) on luciferase-labeled human lung cancer cells (A549-luc) and human lung cancerA549 cells, and to compare the differences in the inhibitory effect on two cell lines. Methods:ATV was used to infectA549-luc cells andA549 cells respectively. WST-1 and crystal violet staining were used to determine the difference in the inhibitory effect of ATV. Hoechst and Annexin V-FITC/PI staining were used to verify the inhibition mode ofATV. Results: WST-1 and crystal violet staining showed thatATV had significant inhibitory effect on bothA549-luc and A549 cells ( P <0.05). ATV showed significant inhibitory effect on both cells at 24, 48 and 72 h ( P <0.05 or P <0.01), and reached the peak at 72 h; ATV at concentrations of 1, 10 and 100 MOI all showed inhibitory effect on both cells, and reached the peak at 100 MOI. Hoechst staining showed that A549-luc cells and A549 cells infected with ATV showed typical nuclear fragmentation and marginal set. The results of Annexin V-FITC/PI Flow cytometry showed that ATV infection resulted in apoptosis of A549-luc and A549 cells, which was in a time-dependent manner and reached the peak at 72 h( P <0.05 or P <0.01). Conclusion: Insertion of luciferase didn’t significantly change the inhibitory effect and inhibitory mode ofATV onA549-luc cells.ATV exerted its in vitro inhibitory effect onA549-luc and A549 cells by inducing cell apoptosis.