For a long time past viruses have been recognized as being tumoricidal. At present, researchers are still pursuing studies and constructing more suitable oncolytic viruses for treating different malignant tumors. Herpes simplex virus type 1 (HSV-1) has been known as the most potential oncolytic virus among all the viruses. In this overview, we summarize the current situation of oncolytic viruses, the biology of HSV-1, its construction and application of its recombinant, and we debate on the feasibility and prospect of HSV-1 mutants labeled with radionuclides for cancer therapy.
Herpesvirus 1, Human ; genetics ; physiology ; Humans ; Mutation ; Neoplasms ; radiotherapy ; Oncolytic Virotherapy ; methods ; trends ; Oncolytic Viruses ; genetics

Naturally existing Newcastle disease virus (NDV) can specifically execute oncolytic ability in clinical studies. Reports from clinical trials using NDV as oncolytic agents showed promise and warrant results in cancer therapy. In recent years, reverse genetics technology has been used widely in the studies of NDV virology. More recently, the technology was applied to optimize the oncolytic efficacy of NDV, for instance, modification of the F gene, and expression of GM-CSF, IFN-gamma, IL-2 or TNF-alpha. NDV is widely investigated in cancer therapy and will definitely offer a prosperous future for clinical cancer therapeutics. We reviewed the developments of cancer therapy by recombinant NDV using reverse genetics technology, as well as our own experience in this domain.
Animals ; Humans ; Neoplasms ; pathology ; therapy ; Newcastle disease virus ; genetics ; physiology ; Oncolytic Virotherapy ; methods ; Oncolytic Viruses ; genetics ; physiology ; Recombination, Genetic

Naturally occurring reoviruses are live replication-proficient viruses specifically infecting human cancer cell while sparing normal counterpart. Since the discovery of reoviruses in 1950s, reoviruses have shown various degrees of safety and efficacy in pre-clinical or clinical application for human anti-cancer therapeutics. I have recently shown that cellular tumor suppressor genes, such as p53, ATM (Ataxia telangiectasia mutated), and RB (Retinoblastoma associated), are important in determining reoviral oncotropism. Thus, it is interesting to examine whether the aberrancy of c-Myc expression, whose normal function also plays an important role in the maintenance of genomic integrity, could affect reoviral oncolytic tropism. Hs68 cells are non-tumorigenic normal cells and resistant to reoviral cytopathic effects. Importantly, I found that c-Myc overexpression in human HS68 cells effectively induced reovirus cytophatic effects compared to mock expressed cells as shown by the typical reoviral cytophathology and an increased level of caspase-3 activity. Taken together, overexpression of c-Myc could play an important role in determining reoviral oncolytic tropism.
Caspase 3 ; Genes, Tumor Suppressor ; Humans ; Oncogenes ; Oncolytic Viruses ; Telangiectasis ; Tropism

Human adenoviruses are widespread causative agent that induces respiratory diseases, epidemic keratoconjunctivitis and other related diseases. Adenoviruses are commonly used in experimental and clinical areas. It is one of the most commonly used virus vectors in gene therapy, and it has attracted a lot of attention and has a high research potential in tumor gene therapy and virus oncolytic. Here, we summarize the biological characteristics, epidemiology and current application of adenovirus, in order to provide reference for engineering application of adenovirus.
Adenovirus Infections, Human ; epidemiology ; virology ; Adenoviruses, Human ; genetics ; Genetic Engineering ; methods ; trends ; Genetic Vectors ; Humans ; Oncolytic Virotherapy ; trends ; Oncolytic Viruses ; genetics ; Virus Replication

The purpose of this study was to construct a recombinant conditionally replicating adenovirus (CRAd) expressing programmed cell death 5 (pdcd5). Pdcd5 gene was inserted in the E3 region of SG600-a CRAd in which the key genes for virus replication E1a and E1b were controlled under the human telomerase reverse transcriptase promoter (hTERTp) and the hypoxia response element (HRE) respectively, and with a deletion of 24 nucleotides within CR2 region of E1a. The insertion and orientation of all recombined plasmids were confirmed by restriction enzyme digestion and polymerase chain reaction (PCR). The infection efficiencies of a recombined virus carrying enhanced green fluorescent protein (EGFP) in leukemic cell lines were observed by using fluorescence microscope. The relative pdcd5 expression levels of K562 after being infected with SG611-pdcd5 were detected by real-time quantitative PCR. The results showed that the construction of SG611-pdcd5 was completed and confirmed. Pdcd5, hTERTp, HRE, skeleton and fiber11 of recombinant adenovirus SG611-pdcd5 were successfully amplified. The infection efficiencies of SG611-EGFP were all above 70% in both leukemic K562 and MEG-01 cell lines. SG611-pdcd5 expressed pdcd5 with high efficiency in leukemic cells as compared with Ad-pdcd5 or SG611 (p < 0.001). The expression level of pdcd5 increased gradually along with the increase of MOI. It is concluded that the triple-regulated adenovirus of SG611-pdcd5 containing the pro-apopro-tic gene pdcd5 has been successfully established with high pdcd5 expression level in leukemic cells, indicating that the recombinant adenovirus, SG611-pdcd5, promises further development of targeted tumor gene therapy.
Adenoviridae ; genetics ; Apoptosis Regulatory Proteins ; genetics ; Genetic Therapy ; methods ; Neoplasm Proteins ; genetics ; Oncolytic Viruses ; genetics ; Promoter Regions, Genetic ; Telomerase ; genetics

Oncolytic herpes simplex virus (HSV) can replicate in and kill cancer cells without harming normal tissue. G47delta is a third-generation HSV vector. In this study, the therapeutic effects of G47delta on human nasopharyngeal carcinoma (NPC) were determined in vitro and in vivo. The human NPC cell lines CNE-2 and SUNE-1, primary normal nasopharyngeal epithelial cells (NPECs), and immortalized nasopharyngeal cells NP-69 and NPEC2/Bmi1 were infected with G47delta at different multiplicities of infection (MOIs). The survival of infected cells was observed daily. Two subcutaneous models of NPC were established with CNE-2 and SUNE-1 in Balb/c nude mice. G47delta or virus buffer as control was injected into the subcutaneous tumors. Tumor size was measured twice a week, and animals were euthanized when the diameter of their tumors exceeded 18 mm or when the animals appeared moribund. For the NPC cell lines CNE-2 and SUNE-1, more than 85% and 95% of cells were killed on day 5 after G47delta infection at MOI = 0.01 and MOI = 0.1, respectively. Similar results were observed for an immortalized cell line NPEC2/Bmi-1. A moderate effect of G47delta was also found on another immortalized cell line NP-69, of which only 27.7% and 75.9% of cells were killed at MOI = 0.01 and MOI = 0.1, respectively. On the contrary, there was almost no effect observed on NPECs. The in vivo experiments showed that tumors in mice in the G47delta-treated group regressed completely, and the mice exhibited much longer survival time than those in the control groups. Our results suggest that the potential therapeutic effects of G47delta would be applicable for treatment of NPC patients in the future.
Animals ; Apoptosis ; Carcinoma ; Cell Line, Tumor ; Female ; Humans ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Nasopharyngeal Neoplasms ; pathology ; therapy ; virology ; Oncolytic Virotherapy ; methods ; Oncolytic Viruses ; physiology ; Simplexvirus ; physiology ; Xenograft Model Antitumor Assays

OBJECTIVETo construct an oncolytic adenovirus with the DD3 promoter regulation, expressing small hairpin RNA and targeting the SATB1 gene (SATBI-shRNA), and to evaluate its potential for inhibiting the growth of human prostatic carcinoma cells (LNCaP) in vitro.

METHODSSATB1-shRNA expression cassettes containing the H1 promoter were produced by PCR from pSilencer3. 1-SATB1 and inserted into the pZD55 vector, and the recombinant plasmid pZD55-SATB1-shRNA was constructed, pZD55SATB1-shRNA and pZXC2-DD3-E1A were digested with EcoRV and Xba I , and the obtained expression cassettes linked each other to construct the recombinant plasmid pDD3-ZD55-SATB1, which was cotransfected with the pBHGE3 packaging plasmids mixture into 293 cells by Effectence. The recombined adenoviruses DD3-ZD55-SATB1 were identified by PCR. Viruses were propagated on HEK293 cells and purified by standard techniques, and the functional PFU titers determined by plaque assay on 293 cells. The antitumor potential of DD3-ZD55-SATB1 to LNCaP was evaluated by the crystal violet dye method. The expression level of the E1A gene was detected by Western blot, and that of the SATB1 gene in the adenovirus-infected LNCaP cells by both Western blot and RT-PCR.

RESULTSAn oncolytic adenovirus expressing SATB1-shRNA with the DD3 promoter regulation, DD3-ZD55-SATB1, was constructed successfully, whose functional PFU titer was 1.2 x 10(10) PFU/ml. DD3-ZD55-SATB1 showed an obvious cytopathic effect and a selective expression of E1A in the adenovirus-infected LNCaP cells; it exhibited a high LNCaP-targetability and specific SATB1-silencing effect.

CONCLUSIONThe successful construction of the oncolytic adenovirus DD3-ZD55-SATB1 offers a new tool for researches on the gene therapy for human prostate cancer.

Adenoviridae ; genetics ; Carcinoma ; therapy ; Cell Line, Tumor ; Genetic Vectors ; Humans ; Male ; Matrix Attachment Region Binding Proteins ; genetics ; Oncolytic Virotherapy ; methods ; Oncolytic Viruses ; genetics ; Promoter Regions, Genetic ; Prostatic Neoplasms ; therapy ; RNA Interference ; RNA, Small Interfering ; genetics

The E1A gene was obtained by PCR with QBI-293A cell genome DNA as template. After enzyme digestion, the E1A gene was ligated to transfer vector pAdTrack-CMV. The positive clone pAdTrack-CMV-E1A were lineared by PmeI and co-transformed with pAdEasy-1 in BJ5183 E. coli. The recombinant adenovirus vector pAdEasy-1-pAdTrack-CMV-E1A were digested by PacI and transfected into QBI-293A cells with liposomes. The oncolytic recombinant adenovirus Ad-E1A was obtained after 7 days. The results showed that this oncolytic adenovirus Ad-E1A can replicate in ECV304 cells and inhibit growth of ECV304 cell. In addition, it also decreased the secretion of VEGF and expression of NF-kappaB of ECV304 cells, indicating that Ad-E1A have potential of inhibition of tumor metastasis.
Adenoviridae ; genetics ; physiology ; Adenovirus E1A Proteins ; biosynthesis ; genetics ; Cell Proliferation ; Cells, Cultured ; Endothelial Cells ; cytology ; metabolism ; Humans ; Oncolytic Virotherapy ; Oncolytic Viruses ; genetics ; physiology ; Promoter Regions, Genetic ; Umbilical Veins ; cytology ; metabolism

In order to evaluate the biological activity in vitro and the antitumor effects of 131I-conditionally replicating oncolytic adenovirus KH901 on HepG2 human hepatoma xenografts, the leves of GM-CSF expression were determined by ELISA method. A panel of tumor and normal cells was infected with recombinant adenovirus KH901 at MOI of 10 PPC. The medium was harvested to determine the bioactivity of GM-CSF after 24 hours. Nude mice bearing HepG2 human hepatoma xenografts were given 131-KH901. Antitumor effects were assessed using endpoints of tumor growth delay. The data showed that after 24 hours 131-KH901 replicated hugely in tumor cells and produced significant amount of GM-CSF 183.27 +/- 6.90 pg/ml, while producing very small amount of GM-CSF 20.44 +/- 0.77 pg/ml in normal cells. In the treatment of tumor, 131I-KH901 showed higher restraint rate (71.3%) compared to 131I (22.7%) or KH901 (52.7%). Therefore, 131-KH901 can inhibit the growth of human hepatoma cell in nude mice and it may be a potential drug for treating liver cancer.
Adenoviridae ; genetics ; metabolism ; Animals ; Female ; Granulocyte-Macrophage Colony-Stimulating Factor ; genetics ; metabolism ; Hep G2 Cells ; Humans ; Iodine Radioisotopes ; Liver Neoplasms, Experimental ; diagnostic imaging ; pathology ; virology ; Male ; Mice ; Mice, Nude ; Oncolytic Virotherapy ; Oncolytic Viruses ; genetics ; metabolism ; Radionuclide Imaging

OBJECTIVETo investigate the inhibitive effects of chimeric oncolytic adenovirus SG235 on leukemia cells in vitro.

METHODSThe ability of SG235 to infect leukemia cells and the expression of CD46 on blasts from the patient with leukemia were detected by flow cytometry (FACS). The cytotoxicity of the virus was evaluated by MTT assay. Apoptosis induced by SG235 was detected with Annexin-V/PI staining and TUNEL assay followed by FACS analysis.

RESULTThe majority of leukemia cells from the patient with acute leukemia was CD46-positive. GFP-positive cells were 45.1%, 35.7%, 54.2%, 37.0%, 30.1%, %67.1, 17.2% and 33.1% in Mutz-1, Kasumi-1, K562, HL60, Molt- 4, RPMI8226, L428, and Jurkat cell lines treated with SG235-EGFP vector at MOI (multiplicity of infection) of 50 for 48 h.SG235 treatment resulted in marked growth inhibition and apoptosis of Kassumi-1 cells, and also significantly inhibited expression of p-Akt.

CONCLUSIONThe chimeric oncolytic adenovirus SG235 can infect leukemia cell effectively and results in the growth inhibition and apoptosis of Kasumi-1 cells in vitro.

Adenoviridae ; genetics ; Apoptosis ; Cell Line, Tumor ; Cell Proliferation ; Genetic Vectors ; Humans ; Leukemia ; genetics ; metabolism ; pathology ; Membrane Cofactor Protein ; metabolism ; Oncolytic Viruses ; Transfection