Conventional cancer therapies, such as radiotherapy and chemotherapy, often damage normal cells and may induce new tumors. Oncolytic viruses (OVs) selectively target tumor cells while sparing normal cells. Most OVs used in clinical trials have been genetically engineered to enhance their ability to target tumor cells and activate immune responses. To develop a specific OV-based approach for treating cervical cancer, this study constructed an oncolytic adenovirus that delivered a base editor targeting oncogenes to achieve efficient killing of tumor cells through inhibiting tumor growth and directly lysing tumor cells. We utilized the human telomerase reverse transcriptase (TERT) promoter to drive the expression of adenovirus early region 1A (E1A) and successfully constructed the P-hTERT-E1A-GFP vector, which was validated for its activity in cervical cancer cells. Given the critical role of the MYC oncogene in the research of oncology, identifying efficient editing sites for the MYC oncogene is a key step in this study.Three MYC-targeting gRNAs were engineered and co-delivered with ABE8e base editor plasmids into HEK293T cells. Following puromycin selection, Sanger sequencing demonstrated differential editing efficiencies: MYC-1 (43%), MYC-2 (25%), and MYC-3 (35%), identifying MYC-1 as the most efficient editing locus. By constructing the P-ABEs-hTERT-E1A-GFP and P-MYC gRNA-hTERT-E1A-GFP vectors, we successfully packaged the virus and confirmed its specificity and efficacy. The experimental results demonstrate that this novel oncolytic adenovirus effectively inhibits the growth of HeLa cells in vitro, providing new experimental evidence and potential strategies for treating cervical cancer based on the HeLa cell model.
Humans ; Uterine Cervical Neoplasms/pathology* ; Oncolytic Viruses/genetics* ; Female ; HEK293 Cells ; Oncolytic Virotherapy/methods* ; Adenoviridae/genetics* ; Gene Editing/methods* ; Telomerase/genetics* ; Adenovirus E1A Proteins/genetics* ; Genetic Vectors/genetics* ; HeLa Cells

This study aims to investigate the potential of oncolytic nanoparticles encapsulating Coxsackievirus A21 (CVA21) full-genome mRNA (CVA21@ONP) to resurrect CVA21 and induce apoptosis in host cells, as well as the antitumor immune effects of CVA21@ONP in immunocompetent tumor-bearing BALB/c mice. We used lipid nanoparticles (LNPs) to encapsulate CVA21 full-genome mRNA, thus preparing CVA21@ONP. The killing efficacy of CVA21@ONP was determined by the plaque assay and cell counting kit-8 (CCK-8), and the apoptosis in HT29 and CT26-iRFP cells was evaluated by flow cytometry. Mice were administrated with CVA21@ONP at high and low doses intratumorally, and the growth of tumors expressing infra-red fluorescent protein (iRFP) was monitored. Additionally, the types and changes of immune cells in the spleen were analyzed by flow cytometry. The results demonstrated that CVA21@ONP successfully resurrected CVA21 in both HT29 and U87MG cells. The plaque assay revealed robust killing effects of CVA21@ONP against both human and murine cell lines, and flow cytometry results showed increased early and late apoptotic cells. Notably, intratumoral detection revealed significantly down-regulated expression of iRFP in both high- and low-dose CVA21@ONP groups. Flow cytometry results further indicated that CVA21@ONP treatment effectively reduced the levels of immunosuppressive cells, including myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs), in the spleen, while enhancing T cell-dependent antitumor immune responses. These findings suggest that CVA21@ONP can replicate and survive extensively both in vitro and in vivo, activating the immune system of mice administrated with CVA21@ONP to target cells at the tumor site, thereby remodeling the tumor immune microenvironment and accelerating the suppression or even complete regression of tumors. The oncolytic performance of CVA21@ONP has been verified through intratumoral injection administration in this study, aimed at further exploring its therapeutic potential and promoting the development of the field of tumor treatment.
Animals ; Nanoparticles/chemistry* ; Mice ; Mice, Inbred BALB C ; Humans ; Apoptosis ; Oncolytic Viruses/genetics* ; Oncolytic Virotherapy/methods* ; Cell Line, Tumor ; RNA, Messenger/genetics* ; HT29 Cells

To investigate the mechanism of the major capsid protein VP5 (encoded by the UL19 gene) of oncolytic herpes simplex virus type Ⅱ (oHSV2) in regulating the antitumor function of immune cells, we constructed a mouse breast cancer cell line 4T1-iRFP-VP5-GFP stably expressing VP5 protein, near-infrared fluorescent protein (iRFP), and green fluorescent protein (GFP) by using the PiggyBac transposon system. Flow cytometry and Western blotting were employed to screen the monoclonal cell lines expressing both GFP and VP5 and examine the expression stability of UL19 in the constructed cell line. The results of SYBR Green I real-time PCR and Western blotting showed that the copies of UL19 and the expression level of VP5 protein in the 15th passage of 4T1-iRFP-VP5-GFP cells were significantly higher than those in the 4T1 cells transiently transfected with UL19, demonstrating the stable insertion of UL19 into the 4T1 cell genome. The real-time cell analysis (RTCA) was employed to monitor the proliferation of 4T1-iRFP-VP5-GFP cells, which showed similar proliferation activity to their parental 4T1 cells. Further studies confirmed that NK92 cells exhibited stronger cytotoxicity against 4T1-iRFP-VP5-GFP cells than against 4T1 cells. This study layed a foundation for elucidating the role of VP5 protein in regulating immune cells, including T cells and NK cells, via HLA-E in 4T1 cells to exert the anti-tumor function.
Animals ; Mice ; DNA Transposable Elements/genetics* ; Cell Line, Tumor ; Capsid Proteins/biosynthesis* ; Transfection ; Green Fluorescent Proteins/metabolism* ; Oncolytic Viruses/genetics* ; Female ; Simplexvirus/genetics*

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

OBJECTIVEThe aim of this study was to construct a new oncolytic virus oHSV2hGM-CSF and evaluate its oncolytic activity in vitro and in vivo in parallel with oHSV1hGM-CSF.

METHODSoHSV2hGM-CSF was a replication-competent, attenuated HSV2 based on the HG52 virus (an HSV2 strain). It was engineered to be specific for cancer by deletion of the viral genes ICP34.5 and ICP47 and insertion of the gene encoding hGM-CSF. To measure the in vitro killing effect of the virus, 15 human tumor cell lines (HeLa, Eca-109, PG, HepG2, SK/FU, CNE-2Z, PC-3, SK-OV3, A-549, 786-0, MCF-7, Hep-2, HT-29, SK-Mel-28, U87-MG) and mouse melanoma (B16R) cell line were seeded into 24-well plates and infected with viruses at MOI = 1 (multiplicity of infection, MOI), or left uninfected. The cells were harvested 24 and 48 hours post infection, and observed under the microscope. For animal studies, the oncolytic viruses were administered intratumorally (at 3-day interval) at a dose of 2.3 x 10(6) PFU (plaque forming unit, PFU) for three times when the tumor volume reached 7-8 mm3. The tumor volume was measured at 3-day intervals and animal survival was recorded.

RESULTSBoth oHSV2hCM-CSFand oHSV1hGM-CSF induced widespread cytopathic effects at 24 h after infection. OHSV2hGM-CSF, by contrast, produced more plaques with a syncytial phenotype than oHSV1hGM-CSF. In the in vitro killing experiments for the cell lines HeLa, HepG2, SK-Mel-28, B16R and U87-MG, oHSV2hGM-CSF eradicated significantly more cells than oHSV1hGM-CSF under the same conditions. For the mouse experiments, it was observed that oHSV2hGM-CSF significantly inhibited the tumor growth. At 15 days after B16R tumor cells inoculation, the tumor volumes of the PBS, oHSV1hGCM-CSF and oHSV2hGM-CSF groups were (374.7 +/- 128.24) mm3, (128.23 +/- 45.32) mm3 (P < 0.05, vs. PBS group) or (10.06 +/- 5.1) mm3 (P < 0.01, vs. PBS group), respectively (mean +/- error). The long term therapeutic effect of oHSV2hGM-CSF on the B16R animal model was evaluated by recording animal survival over 110 days after tumor cells inoculation whereas all the mice in the PBS group died by day 22 (P < 0.01). The anti-tumor mechanism of the newly constructed oHSV2hGM-CSF against B16R cell tumor appeared to include the directly oncolytic activity and the induction of anti-tumor immunity to some degree.

CONCLUSIONThe findings of our study demonstrate that the newly constructed oHSV2hGM-CSF has potent anti-tumor activity in vitro to many tumor cell lines and in vive to the transplanted B16R tumor models.

Animals ; Cell Line, Tumor ; Female ; Gene Deletion ; Genetic Engineering ; Granulocyte-Macrophage Colony-Stimulating Factor ; genetics ; Herpesvirus 2, Human ; genetics ; immunology ; Humans ; Immediate-Early Proteins ; genetics ; metabolism ; Melanoma, Experimental ; pathology ; therapy ; virology ; Mice ; Mice, Inbred C57BL ; Oncolytic Virotherapy ; methods ; Oncolytic Viruses ; genetics ; physiology ; Random Allocation ; Tumor Burden ; Viral Proteins ; genetics ; metabolism ; Xenograft Model Antitumor Assays

OBJECTIVETo study the effect of CEA gene regulation on the anti-tumor activity of oncolytic adenovirus H101 to esophageal carcinoma, and to explore the intrinsic factors influencing H101 sensitivity.

METHODSStable human esophageal cancer cell line EC9706 cells with lower (EC9706-SCEA) and higher CEA expression (EC9706-CEA) were chosen, thawed and cultured, and then to analyse the influence of CEA expressed at different levels on cell growth. The cytotoxic effect of H101 was assayed by in vitro and nude mouse in vivo.

RESULTSThe cell growth experiment showed that the population doubling time of EC9706-SCEA, EC9706-CEA and EC9706 cells were (30.9 ± 2.0) h, (31.1 ± 2.5) h and (29.1 ± 2.6) h, respectively, showing no significant difference among them (P > 0.05). The cytotoxic activity of H101 was higher on EC9706-SCEA than on other four groups, when MOI was ≥ 0.01 PFU (P < 0.05). The mouse experiment showed that H101 inhibited the growth of transplanted tumors in all experimental groups. Its effect on CEA-silenced tumors (inhibition rate was 61.5% to 74.5%) was significantly higher than that on CEA-overexpression tumors (32.3% to 38.5%) and control EC9706 transplanted tumors (35.5% to 44.8%). There was a significant difference between them (P < 0.05).

CONCLUSIONSThe results in vitro and in vivo experiments show that H101 can enhance the cytotoxic effect on EC9706 cells with lower CEA expression. To silence the expression of CEA may provide a novel strategy for target gene therapy of esophageal carcinoma.

Adenoviridae ; physiology ; Animals ; Carcinoembryonic Antigen ; genetics ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; Esophageal Neoplasms ; metabolism ; pathology ; therapy ; Female ; Gene Silencing ; Humans ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation ; Oncolytic Virotherapy ; Oncolytic Viruses ; physiology ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; genetics ; Tumor Burden

To establish a detection method of oncolytic adenovirus/p53 and standard of quality control, human telomerase reverse transcriptase (hTERT) promoter, CMV fusion promoter containing hypoxia reaction element (HRE) and p53 gene were identified by vector DNA restriction enzyme digestion and PCR analysis. The result conformed that all modified regions were in consistent with theoretical ones. Particle number was 2.0 x 10(11) mL(-1) determined by UV (A260). Infectious titer was 5.0 x 10(10) IU mL(-1) analyzed by TCID50. In vitro p53 gene expression in human lung cancer cell H1299 was determined by ELISA, and A450 ratio of nucleoprotein in virus infection group to control group was 5.2. Antitumor potency was evaluated by cytotoxicity assay using human lung cancer cell A549, and the MOI(IC50) of this gene therapy preparation was 1.0. The tumor cells targeted replication ability of recombinant virus was determined by TCID50 titer ratio of filial generation virus between human lung cancer cell A549 and human diploid epidermal fibrolast BJ cells after infected by virus with same MOI. TCID50 titer ratio of tumor cell infection group to normal cell infection control group was 398. The IE-HPLC purity of virus was 99.5%. There was less than 1 copy of wild type adenovirus within 1 x 10(7) VP recombinant virus. Other quality control items were complied with corresponding requirements in the guidance for human somatic cell therapy and gene therapy and Chinese pharmacopeia volume III. The detection method of oncolytic adenovirus/p53 was successfully established for quality control standard. The study also provided reference for quality control of other oncolytic viral vector products.
Adenoviridae ; genetics ; metabolism ; physiology ; Cell Line, Tumor ; Gene Expression Regulation, Neoplastic ; Genes, p53 ; Genetic Therapy ; Genetic Vectors ; Humans ; Neoplasms ; metabolism ; pathology ; virology ; Oncolytic Viruses ; genetics ; metabolism ; physiology ; Quality Control ; Recombinant Fusion Proteins ; genetics ; metabolism ; Transfection ; Virus Replication

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

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

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