Search

Background The clustered regularly interspaced short palindromic repeats-associated protein 9 (CRISPR-Cas9) is thought to have promising clinical potential. However, the off-target effects of Cas9 are a major concern for its application. Therefore, we hypothesized that the adverse effects of off-target gene editing might be minimized if the human codon-optimized Streptococcus pyogenes Cas9 (hCas9) could be specifically expressed in cancer cells. Materials and methods We constructed a chimeric adenoviral vector, Ad5F35-MKp-hCas9, and infected human bladder cancer cell lines with this vector. The confirmation of hCas9 gene expression was performed in 3-4 days after from infection. Results hCas9 gene expression was observed in Ad5F35-MKp-hCas9 infected bladder cancer cells but not in non-malignant cells. Conclusion Our study showed that the Ad5F35-MKp-hCas9 vector is capable of expressing the hCas9 gene with high specificity in bladder cancer cells. These findings may help in minimizing the risk of off-target effects of gene editing.

Tumor-derived extracellular vesicles (EVs), as tumor vaccines, carry tumor-associated antigens (TAAs), and were expected to transfer TAAs to antigen-presenting cells. However, treatment with tumor-derived EVs exhibited no obvious antitumor effect on the established tumors, likely due to their immuno-suppressive functions, and also to the poor immunogenicity of TAAs. In order to improve the immune stimulating properties, EVs expressing a highly immunogenic bacterial antigen, 6 kDa early secretory antigenic target (ESAT-6), from Mycobacterium tuberculosis were prepared by genetically modifying the parent tumor cells with a plasmid coding for ESAT-6. Cultured B16 tumor cells were transfected with a ternary complex system consisting of pDNA, polyethylenimine (PEI), and chondroitin sulfate. The cells that were transfected with the ternary complex secreted EVs with a higher number of ESAT-6 epitopes than those transfected by a conventional DNA/PEI binary complex, due to the low cytotoxicity, and durable high expression efficiency of the ternary complex systems. The EVs presenting the ESAT-6 epitope (ESAT-EV) were collected and explored as immune modulatory agents. Dendritic cells (DCs) were differentiated from mouse bone marrow cells and incubated with ESAT-EV. After incubating with the EVs for one day, the DCs expressed a significantly higher level of DC maturation marker, CD86. The DCs treated with ESAT-EV showed a significantly improved antitumor activity in tumor-bearing mice.

Background A549 carrier cells infected with oncolytic adenovirus can induce complete tumor reduction of subcutaneous ovarian tumors but not intraperitoneal disseminated ovarian tumors. This appears to be a result of the insufficient antitumor effect of A549 carrier cells. Therefore, in the present study, we cloned a novel carrier cell with the aim of improving the antitumor effects. Methods Carrier cells infected with oncolytic adenovirus AdE3‐midkine with a midkine promoter were cloned by limiting dilution. We examined the antitumor effects of these cells on subcutaneous and intraperitoneal OVHM ovarian tumors in a syngeneic mouse model. Biosafety tests were conducted in beagle dogs and rabbits. Results We cloned EHMK‐51‐35 carrier cells with 10‐fold higher antitumor effects compared to A549 carrier cells in vitro. EHMK‐51‐35 carrier cells co‐infected with AdE3‐midkine and Ad‐mGM‐CSF induced a 100% complete tumor reduction in subcutaneous tumors and a 60% reduction of intraperitoneal disseminated tumors. Single‐dose acute toxicity test on beagle dogs with EHMK‐51‐35 carrier cells co‐infected with AdE3‐midkine and Ad‐cGM‐CSF showed no serious side effects. Biologically active adenoviruses were not detected in the blood, saliva, feces, urine or whole organs. In a chronic toxicity test, VX2 tumors in rabbits were injected five times with EHMK‐51‐35 carrier cells infected with AdE3‐midkine and these rabbits showed no serious side effects. Conclusions Significant antitumor effects and safety of cloned EHMK‐51‐35 carrier cells were confirmed in intraperitoneal ovarian tumors and toxicity tests, respectively. These findings will be extended to preclinical efficacy studies using dogs and cats, with the aim of conducting human clinical trials on refractory solid tumors.

Objective: In this study, we evaluated the management of cervical intraepithelial neoplasia (CIN) in pregnant women and evaluated the postpartum prognosis. Methods: Twenty-four pregnant women, who were diagnosed with CIN at Ehime University Hospital between January 2008 and October 2012, were recruited. The mode of delivery and pathophysiological examination results in the postpartum period were evaluated. Results: Four patients were antenatally diagnosed with either CIN1 or CIN2. Of these patients, CIN regressed or remained stable during pregnancy, and there was no disease progression in the postpartum period. Nine patients were diagnosed with severe dysplasia (CIN3) and eleven patients had carcinoma in situ (CIS). Of these patients, 5/9 (55%) and 4/11 (36%), respectively, had disease regression postnatally. No CIN lesion progressed to invasive carcinoma after delivery. Conclusions: We determined that many cases diagnosed antenatally with CIN regressed during the postpartum period, regardless of the grade of CIN. We recommend a conservative management strategy with careful ante- and postpartum examinations for pregnant women with CIN.

We succeeded in the development of a new method for enantioselective synthesis of α-substituted-β-amino acid derivatives. Thus, nickel(0)-promoted carboxylation of ynamide gave the α-substituted-β-aminoacrylate derivative in a highly regioselective manner. Then, rhodium-catalyzed asymmetric hydrogenation of the α-substituted β-aminoacrylate produced the corresponding α-substituted β-amino acid derivative as an optically active form.

Background Although replication-competent viruses have been developed for treating cancers, their cytotoxic effects are insufficient as a result of infection inhibited by the generation of neutralizing antibodies, and systemic administration is difficult as a result of the life-threatening serious side-effects of virus-induced cytokine surge. To overcome these critical problems, we devised a plasmid/polycation/polyanion complex and assessed the potential of ternary plasmid complexes coated with chondroitin sulfate in gene therapy for ovarian cancer. The antitumor effects of chondroitin sulfate-coated complex as an anionic component were compared with those of hyaluronic acid on ovarian cancer. Methods Plasmid harboring the gene of murine granulocyte macrophage-colony-stimulating factor (mGM-CSF) was complexed with polyethyleneimine (PEI) and hyaluronic acid or chondroitin sulfate. Murine ovarian cancer cells were injected into (C57BL/6 × C3H/He) F1 mice to prepare a subcutaneous or intraperitoneal tumor model. Results DNA/PEI was charged positively and DNA/PEI/chondroitin sulfate or DNA/PEI/hyaluronic acid was charged negatively. Plasmid-green fluorescent protein (GFP)/PEI coated with 10-kilodalton (kDa) chondroitin sulfate increased transfection efficiency compared to coating with chondroitin sulfate of higher-molecular-weight or hyaluronic acid. The transfection efficiency of GFP/PEI/10-kDa chondroitin sulfate in ovarian cancer cells was six-fold higher than that in normal cells. Intraperitoneal injection of mGM-CSF/PEI coated with 10-kDa chondroitin sulfate prolonged survival compared to that coated with hyaluronic acid. Intratumoral injection of mGM-CSF/PEI coated with 10-kDa chondroitin sulfate achieved mouse survival rates of 100%, although that with hyaluronic acid did not. Conclusions These findings suggest that GM-CSF/PEI coated with 10-kDa chondroitin sulfate has the potential for use in gene therapy of ovarian cancer. Copyright © 2012 John Wiley & Sons, Ltd.

Background Although cancer therapy using replication-selective oncolytic adenoviruses has been available for many years, its anti-tumor efficacy is suboptimal as a result of low and nonspecific infectivity that depends on coxsackie adenovirus receptor expression of the target cancer and normal cells, and generation of an anti-adenovirus neutralizing antibody. In addition, concerns of triggering a severe innate immune response against the adenovirus limit the systemic administration. We developed the carrier cell-based oncolytic virus system (CBOVS) using irradiated tumor cells as carrier cells and concealing the adenovirus (Ad-IAI.3B) inside to improve the specific infectivity. We investigated the anti-tumor effect of CBOVS in a multiple lung tumor mouse model. Methods The ability of CBOVS to infect Ad-IAI.3B to the target cancer cells was examined in vitro in the presence of anti-adenovirus antibodies. To evaluate the systemic effect of CBOVS, we intravenously injected CBOVS into mice with lung tumors (KLN205 cell lines). Results CBOVS enhanced the infectivity of Ad-IAI.3B to tumor cells in the presence of anti-adenovirus antibodies in vitro. Intravenous injections of CBOVS produced an accumulation of the adenovirus in the lung-bearing tumors and produced a strong anti-tumor effect in vivo. Furthermore, lymphocytes collected from the CBOVS-treated mice induced an increase in cytokines related to the Th1 response (interferon-γ, interleukin-12) by pulsing with KLN205. Conclusions These findings suggest that CBOVS could protect adenoviruses from neutralizing antibodies and systemically deliver them to lung tumors. Furthermore, CBOVS appears to have potential as a tumor cell vaccine that activates cytotoxic immunity against cancer cells. Copyright © 2011 John Wiley & Sons, Ltd.

Background The squamous cell carcinoma antigen (SCCA) serves as a serological marker for squamous cell carcinomas. Molecular cloning of the SCCA genomic region has revealed the presence of two tandemly arrayed genes: SCCA1 and SCCA2. SCCA1 gene is up-regulated in squamous cell carcinoma cells. We analyzed the proximal region of the SCCA1 promoter and the antitumor effect of oncolytic adenovirus driven by the SCCA1 promoter in squamous cell carcinoma cells. Methods The SCCA1 promoter was analyzed by dual luciferase assay and substituted with the E1A promoter to construct the oncolytic adenovirus to determine the squamous cell carcinoma-specific cell lysis. Results Deletion analysis of SCCA1 promoter identified a 175-bp core promoter region and an enhancer region at −525 to −475 bp upstream of the transcription start site. The transcriptional activity of the SCCA1 promoter was up-regulated in squamous cell carcinoma cells. Five tandem repeats of enhancer increased SCCA1 promoter activity by four-fold. Oncolytic adenovirus driven by this SCCA1 enhancer-promoter complex specifically killed squamous cell carcinoma cells in vitro and in vivo. A549 carrier cells infected with the oncolytic adenovirus induced complete regression of syngeneic squamous cell carcinoma cell tumor by overcoming immunogenicity and adenovirus-mGM-CSF augmented the antitumor effect of carrier cells. Conclusions SCCA1 was up-regulated in squamous cell carcinoma cells and oncolytic adenovirus driven by SCCA1 promoter specifically killed these cells. These findings suggest that SCCA1 promoter is a potential target of gene therapy for squamous cell carcinoma. Copyright © 2010 John Wiley & Sons, Ltd.

The transduction efficacy of adenovirus serotype 5 (Ad5) vector in human renal carcinoma cells is generally low due to the down-regulated expression of Coxsackie and adenovirus receptor (CAR) in target cells. By contrast, the infectivity of adenovirus serotype 35 vectors depends on the binding rate to CD46 receptor, independent of CAR. In this study, we examined whether an adenovirus vector containing chimeric type 5 and type 35 fiber proteins (Ad5/F35) increases transduction efficiency compared to Ad5 vector in human renal carcinoma cells in vitro. The expression of CAR was much lower in the human renal carcinoma cells than in control HEK293 cells. By contrast, the expression of CD46 was similar and perhaps at a higher level in the human renal carcinoma cells than in the HEK293 cells. The transduction efficacy of Ad5/F35 vector was dramatically higher compared to that of Ad5 in human renal carcinoma cells, and was correlated to the expression of CD46. Thus, Ad5/35 vector may be useful for the development of novel gene therapy approaches to renal cell carcinoma.

We evaluated the long-term safety and efficacy of Ad-OC-TK (recombinant adenoviral vector carrying an osteocalcin promoter-driven herpes simplex virus thymidine kinase gene) plus VAL (valacyclovir) gene therapy for hormone-refractory prostate cancer. Ad-OC-TK/VAL therapy is the first in vivo adenovirus-mediated gene therapy to be used to treat metastatic prostate cancer, including bone metastasis. Six patients were enrolled in this trial, and two doses of Ad-OC-TK (2.5 x 10(9) or 2.5 x 10(10) plaque-forming units) were injected into locally recurrent tumor or bone metastasis on day 1 and day 8. Patients were also given VAL (3 g/day) for 21 days. Safety and efficacy were evaluated for at least 8 months in each patient. All patients tolerated this therapy with no serious adverse events. One prostate-specific antigen (PSA) response (from 318.3 to 4.9 ng/ml) was observed with a time to PSA progression (TTP) of 12 months. Docetaxel (30 mg/m2 per week) and estramustine (560 mg/day) combination chemotherapy (DE) was given to three docetaxel-naive patients on PSA failure after gene therapy. All three patients had a PSA response to DE therapy with 21, 7, and 4 months of TTP. These results suggest that additional trials are warranted.

Objectives To develop a novel therapeutic strategy against human bladder cancer using Ad-MK-E1a—a midkine (MK) promoter-regulated, conditionally replicating, adenovirus. Methods We tested several human cancer cell lines in vitro, including those of bladder cancer (KK47, 5637, and T24), lung cancer (A549), and head and neck cancer (H891). In each cell line, we examined MK mRNA expression by TaqMan real-time quantitative polymerase chain reaction, MK promoter activity, after plasmid transfection, using a luciferase assay, and the transduction efficiency by co-transfection with the cytomegalovirus-beta-gal plasmid. In these cells, we assessed the cell type-specific replication of Ad-MK-E1a virus by measuring the E1a DNA copy number by real-time polymerase chain reaction and the cell growth inhibition due to this virus using the Alamar blue assay. In animal studies, nude mice were subcutaneously inoculated with KK47 cells and later intratumorally injected with phosphate-buffered saline or Ad5-CMV-LacZ or Ad-MK-E1a. Results The MK mRNA expression level and MK promoter-driven luciferase activity were relatively greater and markedly increased, respectively, in the 5637, A549, and KK47 cells than in the T24 and H891 cells. After Ad-MK-E1a infection, the E1a DNA copy number increased more significantly in the KK47, 5637, and A549 cells than in the T24 and H891 cells. At a multiplicity of infection of 0.01, Ad-MK-E1a significantly inhibited KK47 and 5637 cell growth. In vivo, Ad-MK-E1a injection markedly inhibited KK47 tumor growth. Conclusions We have demonstrated the antitumor effect of Ad-MK-E1a in a human bladder cancer model overexpressing MK mRNA.

The CD40 ligand (CD40L) is expressed by T cells and has a critical role in immune system regulation. Interventions targeting CD40L interactions following embryo implantation represent an approach to preventing preeclampsia (PE). To better understand the role of CD40L in PE, we developed a PE mouse model in which we examined how CD40L-induced immune activation affects embryo implantation. Blastocysts were incubated with CD40L-expressing adenovirus and then were transferred into the uterine horns of pseudopregnant ICR mice. Histology, biochemistry and flow cytometry experiments were performed to examine the characteristics of the mouse model. In early pregnancy, decidualization and spiral artery remodeling were reduced in CD40L-transfected mice (CD40L mice) compared with control mice. Hematoxylin-eosin (HE) staining revealed hemorrhaging and excess fibrin deposition at the labyrinth layer-junctional zone interface of the placenta, and PAS staining demonstrated prominent focal and segmental sclerosis with collapsed glomerular capillaries in the kidneys of the CD40L mice. Flow cytometry data showed that interferon-γ production derived from CD4(+) T cells was elevated in the splenic cells of CD40L mice. Blood pressure (measured by the tail-cuff method) and urine albumin concentrations were significantly increased in CD40L mice compared with control mice. Furthermore, the plasma concentrations of soluble Flt-1 and soluble endoglin were increased in CD40L mice, as occurs in human patients with PE. Thus, CD40L-induced T-helper cell type 1 differentiation during embryo implantation may have a critical role in the pathogenesis of a PE-like presentation in a novel mouse model of PE.

Background. One major concern about adenoviral vectors for repetitive gene delivery is the induction of an immune response to the vector, thus impeding effective gene transduction. Methods. To assess the immune response to the adenoviral vector, repetitive gene dosing was performed into rhesus monkey cervix and C3H mouse skin using the adenoviral vector carrying the lacZ gene. Three repetitive intracervical injections of adenovirus- lacZ were done in the rhesus monkey at the intervals of 4 weeks. Gene expression on the second and third injection was completely suppressed. Results. Anti-adenovirus IgG levels and neutralizing antibody titers in the rhesus monkey significantly increased after the first injection of adenovirus. In the C3H mouse, neutralizing antibody titers significantly increased after the first injection of adenovirus- lacZ at more than 10 8 plaque-forming unit (PFU). The repetitive expression of lacZ gene in the mouse skin markedly decreased when the second injection is done more than 2 weeks after the first injection. Chronic low-dose treatment with cyclophosphamide or etoposide markedly suppressed neutralizing antibody titers in the mouse serum and restored the gene expression in the mouse skin on the second and third injection. Conclusions. It is suggested that repetitive gene expression by adenovirus-mediated transfer may be reduced by circulating neutralizing antibodies and could be restored by chronic low-dose treatment with cyclophosphamide or etoposide.

We examined possible application of a regulatory region of midkine (MK) gene, which is frequently upregulated in a number of human tumours but not in normal cells, to cancer gene therapy. We examined transcriptional activity of the MK genomic fragments in paired cell lines, immortalized cells and their parental normal fibroblasts, and found that the MK fragments activated a fused reporter or a suicide gene preferentially in the immortalized cells. Recombinant adenoviruses (Ad), in which the MK fragment was inserted upstream to the E1A gene (AdMK), replicated preferentially in the immortalized cells and were cytotoxie to them. Human hepatocellular carcinoma cells were significantly susceptible to AdMK compared with human normal fibroblasts in vitro and the replication of AdMK was less than that of wild-type Ad in the infected fibroblasts. Hepatocellular carcinoma cells infected with AdMK did not form tumours in immunocompromised mice and intratumoural injection of AdMK into the hepatocellular carcinoma developed in mice retarded the subsequent tumour growth. Expression of E1A and necrosis of tumours were detected in AdMK-injected but not control Ad-injected cases. The MK promoter-driven suicide gene therapy and -mediated replicative Ad can thereby produce cytotoxic effects to immortalized and tumour cells with minimal damage to normal cells.

Infection inhibition of virus by antiviral antibodies is one of the major problems that cancer gene therapy has never shown the significant antitumor activity in human clinical trial. Oncolytic adenovirus-infected A549 carrier cells develop cell fragments and exosomes containing oncolytic adenoviral particles and could infect target cancer cells by overcoming antiadenoviral immunogenicity. A549 carrier cells induce complete tumor reduction in syngeneic subcutaneous mouse tumor model by direct antitumor activity of oncolytic adenovirus, antiadenoviral cytotoxic T lymphocyte and antitumor immunity but not in syngeneic intraperitoneal ovarian cancer mouse model. In this study, we cloned and established a noble carrier cell by limiting dilution to induce the complete tumor reduction of the intraperitoneal ovarian tumor by increasing antitumor activity of carrier cells. Oncolytic adenovirus AdE3-midkine driven by midkine promoter and non-replicative adenovirus Ad-mGM-CSF were used in this study. We cloned a nobel carrier cell from EHMK adenocarcinoma cells by limiting dilution, which were established in our laboratory. EHMK cells were infected with AdE3-midkine and co-cultured with ovarian adenocarcinoma HEY cells with or without antiadenoviral antibodies. In vitro antitumor activity of cloned EHMK carrier cells was calculated by IC50 and compared with that of A549 carrier cells infected with AdE3-midkine. B6C3F1 mouse and cognate ovarian cancer OVHM cell line were used in this study. Mice were injected intraperitoneally with OVHM cells after immunization with adenovirus and treated by carrier cells infected with AdE-midkine with or without Ad-mGM-CSF. Antitumor activity of carrier cells was analyzed by Kaplan Meier survival curve. In vitro antitumor activity of EHMK carrier cells was 1.0±0.1 and 1.1±0.2 that of A549 carrier cells with or without antiadenoviral antibodies, respectively. In vitro antitumor activity of EHMK-51 carrier cells after limiting dilution of EHMK cells was 4.5±1.1 and 3.4±1.9 that of A549 carrier cells with or without antiadenoviral antibodies, respectively. EMHK-51 cells were further cloned by limiting dilution. In vitro antitumor activity of EHMK-51-35 carrier cells was 3.1±1.5 and 2.8±0.9 that of EHMK-51 carrier cells with or without antiadenoviral antibodies, respectively. In comparison with A549 carrier cells, in vitro antitumor activity of EHMK-51-35 carrier cells was 12.5±4.3 and 10.5±5.0 that of A549 carrier cells with or without antiadenoviral antibodies, respectively. In mouse intraperitoneal tumor model, A549 carrier cells infected with AdE3-midkine ± Ad-mGM-CSF did not show any antitumor effect but EHMK carrier cells infected with AdE3-midkine with or without Ad-mGM-CSF showed 40% and 70% complete tumor reduction, respectively. From these results, it is concluded that EHMK-51-35 carrier cells might be potent to treat intraperitoneally metastasized ovarian cancer

OBJECTIVE To assess the potential of p21 as a gene therapy treatment for prostate cancer, by introducing p21 into both androgen-dependent (AD) and -independent (AI) human prostate cancer cell lines via a recombinant adenoviral vector, Ad5CMV-p21, carrying human p21 cDNA. MATERIALS AND METHODS The LNCaP, DU145 and PC-3 human prostate cancer cell lines were cultured and infected with Ad5CMV-p21. Cell growth, cell-cycle progression and tumorigenicity were then assessed by thymidine incorporation into cellular DNA, and cell number, flow cytometry, and tumour growth after inoculating the cells into nude mice. RESULTS Growth was inhibited in Ad5CMV-p21 viral-infected AD and AI prostate cancer cells. The effects were dose-dependent, regardless of the androgen status of the cell lines. Flow cytometric analysis showed that Ad5CMV-p21 arrested cell-cycle progression at G1/S with no appreciable effect on the levels of apoptotic cells. The tumorigenicity of cancer cells infected with Ad5CMV-p21 was greatly reduced in athymic mice. CONCLUSIONS These results suggest that Ad5CMV-p21 may be a new therapeutic agent for human prostate cancer gene therapy.

The use of carrier cells infected with oncolytic viruses in cancer gene therapy is an attractive method because it can overcome viral immunogenicity and induce tumor immunity and significant antitumor activity. To enable human clinical trials of this treatment, acute and chronic toxicity tests must first be performed to ensure safety. IAI.3B promoter, oncolytic adenovirus AdE3- IAI.3B introduced by IAI.3B promoter, and A549 carrier cells infected with AdE3- IAI.3B were highly active in cancer cells but not in normal cells. Freeze-thawing increased the antitumor effect of A549 carrier cells by promoting the translocation of oncolytic adenovirus particles from the nucleus to the cytoplasm following the rupture of the nuclear membranes. No deaths or abnormal blood test data resulted from acute toxicity tests conducted in nude mice after a single dose. In chronic toxicity tests in rabbits, there were no serious side effects after eight doses of 1.25 × 10 7 cells/kg or less for 4 weeks; a significant immune response is known to elicit increased numbers of antiadenovirus antibodies and enlarge the spleen. From these results, it could be concluded that cancer gene therapy of recurrent solid tumors using carrier cells can be safely trialed in humans.

The squamous cell carcinoma antigen (SCCA) serves as a serological marker for squamous cell carcinomas. Molecular cloning of the SCCA genomic region has revealed the presence of two tandemly arrayed genes, SCCA1 and SCCA2 , which are 95% identical in nucleotide sequence. SCCA1 is a papain-like cysteine proteinase inhibitor, while SCCA2 is a chymotrypsin-like serine proteinase inhibitor. We analyzed here the sequence and the promoter activity of the 5′-flanking region of the SCCA1 gene. Deletion analysis of SCCA1 and SCCA2 promoter identified a 471-bp core promoter region upstream of the transcription start site. The transcriptional activity of SCCA1 promoter was up-regulated in squamous cell carcinoma cells, compared with keratinocyte and adenocarcinoma cells. The ratios of SCCA1 to SCCA2 promoter activity in squamous cell carcinoma, keratinocyte and adenocarcinoma cells were respectively 1.6, 5.3 and 2.8. Position −50 of SCCA1 and SCCA2 promoters played an important role in determining the promoter activities of SCCA1 and SCCA2 . These findings suggest that the transcriptional regulation of SCCA1 and SCCA2 might differ among squamous cell carcinoma, keratinocyte and adenocarcinoma cells, and that SCCA1 promoter might be a potential target of gene therapy for squamous cell carcinoma.

Urinary disturbance frequently develops following therapy for cervical cancer; however, no effective medical treatment has so far been reported. Sixty-five patients who developed urinary disturbance after radiation therapy, radical hysterectomy or radical hysterectomy with radiation therapy for cervical cancer underwent urodynamic assessment. Those who underwent radical hysterectomy with radiation therapy experienced the most severe urine loss, as determined by the pad test. All patients showed markedly reduced bladder compliance. A beta2-agonist (mabuterol) significantly improved compliance, bladder capacity and flow rate. It is suggested that medication with mabuterol is a potential novel approach to the treatment of urinary disturbance after therapy for cervical cancer.

We reported previously that direct injection of a recombinant adenovirus (rAd), Ad5CMV-beta-gal, into the cervix of the rhesus monkey resulted in efficient beta-galactosidase expression in the cervix within 3 days. In these studies, we also observed the induction of anti-adenovirus (Ad)-specific immunoglobulin G responses after 22 days. In the continuation of evaluating the anti-Ad-specific immune responses resulting from this approach of gene targeting to the cervix, we measured the cellular immune responses. The introduction of Ad5CMV-beta-gal into the cervix by direct injection, but not by the abrasion technique, resulted in the induction of strong proliferative responses against extracts of cells infected with Ad5CMV-beta-gal but not against control uninfected cells. These responses were initially detected at 22 days postinjection and coincided with the abrogation of transgene expression. Significant levels of proliferative responses were maintained foror =83 days. Multiple injections of rAds had no significant enhancing effect on either the level or longevity of the proliferative responses. At 3 days after the injection of Ad5CMV-beta-gal, when the transgene expression in the cervix was clearly evident, proliferative responses against the rAd were not detectable. However, the production of low but significant amounts of interleukin-10, a cytokine characteristic of T helper type 2 responses that promote humoral immune responses, was observed at the 3-day point in these animals. These results suggest that significant differences exist between the kinetics of transgene expression and the priming of specific host immune responses, and that these differences may be important for devising alternate strategies to improve techniques for Ad-mediated gene therapy of cervical cancer.

Microsatellite instability (MI) has been detected in certain sporadic cancers as well as in hereditary non-polyposis colorectal cancer (HNPCC). In order to determine the precise clinicopathological characteristics of MI in endometrial cancer, we examined 90 sporadic endometrial cancers (83 endometrioid adenocarcinomas, 3 adenosquamous carcinomas, 3 papillary serous carcinomas, and 1 clear cell carcinoma) and eight lesions of endometrial hyperplasia for replication error (RER) using polymerase chain reaction amplification of CA repeated microsatellite sequences at 15 loci. RER was observed in 23 (28%) of the 83 endometrioid adenocarcinomas at at least one locus and in 19 (23%) at two or more loci (RER+ phenotype) in the seven most commonly observed loci, but not in carcinomas of other histological types or in endometrial hyperplasia. Lymphocyte infiltration around carcinoma cells, which is one of the histological features seen in tumors from HNPCC, was severer in RER+ phenotype tumors (79%, 11/14) than in the RER- tumors (25%, 11/44) (marked/moderate infiltration versus slight, P < 0.001, chi 2 test), when 58 tumors with muscular invasion were examined. The RER+ phenotype was associated with a higher parity and gravidity (P < 0.05, Wilcoxon test). However, RER+ phenotype was not associated with tumor stage, histological grade, muscular invasion, lymph node metastasis or patient survival. In conclusion, MI occurs in a subset of endometrial cancers, which often show marked infiltration of lymphocytes around the tumor.

Purpose: Overexpressing or restoring the basal levels of tumor suppressor genes in cancer cells can suppress tumorigenicity of cancer cells. In this communication, we compared tumor suppressive activities of three well-defined tumor suppressive genes (p53, p21WAF1/CIP1, and p16CDKN2) delivered individually to prostate cancer cells with adenoviral vector (Ad).Materials and Methods: Efficacy of growth inhibition by recombinant adenoviruses bearing p53, p21WAF1/CIP1, or p16CDKN2 (Ad5CMV-p53, Ad5CMV-p21, Ad5CMV-p16) genes were tested in vitro on androgen-dependent (LNCaP) and androgen-independent (C4-2, DU-145, and PC-3) human prostate cancer cells, ex vivo and in vivo on PC-3 tumor.Results: Ad5CMV-p53 was observed to exert the greatest growth inhibitory action on all of the cell lines tested; inhibition appeared to be cytolytic. In comparison to control Ad5CMV-PA added samples, the growth inhibitory action of Ad5CMV-p21 and Ad5CMV-p16 appeared to be cytostatic. Ad5CMV-p53 is more effective than Ad5CM...

To explore the potential of an adenoviral antisense RNA transcript for gene therapy of cervical cancer, we introduced the antisense RNA transcript of E6 and E7 genes of human papillomavirus (HPV) 16 into cervical cancer cells harboring HPV 16 via a recombinant adenoviral vector, Ad5CMV-HPV 16 AS and analyzed the effects of expression of these genes on cell growth and tumor growth. Ad5CMV-HPV 16 AS contains the cytomegalovirus-promoter, E6 and E7 genes of HPV 16 in antisense orientation, and the SV40 polyadenylation signal in a mini-gene cassette, which is inserted into the E1-deleted region of modified adenovirus 5. The entire E6/E7 region of HPV 16 was amplified by polymerase chain reaction (PCR) before cloning into the mini-gene cassette. By reverse transcriptase-PCR, HPV 16 E6/E7 antisense RNA was detected in SiHa cells infected with Ad5CMV-HPV 16 AS. The growth of the Ad5CMV-HPV 16 AS-infected cells was greatly suppressed, as evidenced by a decrease in cell count. The growth inhibitory effect of Ad5CMV-HPV 16 AS was significantly enhanced by an adenoviral p53 construct, Ad5CMV-p53. In an ex vivo study in nude mice, tumorigenicity was completely inhibited in mice injected with Ad5CMV-HPV 16 AS-infected SiHa cells. These data suggest that transfection of cervical cancer cells with HPV 16 E6/E7 antisense RNA in a form such as Ad5CMV-HPV 16 AS is a potential novel approach to the therapy of HPV 16-positive cervical cancer.

Deletion of certain chromosomal regions can be demonstrated in malignant cells. Chromosome 16q is one of the regions where allelic loss is frequently detected in carcinoma of the breast and many other tumors, suggesting that gene(s) which retard tumor growth may exist here. To elucidate the clinico-pathological significance of chromosome 16q, loss of heterozygosity (LOH) was investigated using microsatellite polymorphism analysis in 58 patients with endometrial lesions (50 with endometrial carcinoma and 8 who had hyperplasia with or without atypia). When 11 regions of chromosome 16q were examined, LOH was found in 20 patients with carcinoma (40%) and none of the patients with hyperplasia. The tumors of 9 of the 20 patients (45%) showed total loss of 16q, while the others (55%) showed partial deletion. Tumors with LOH were histologically less differentiated than those without LOH (P = 0.038, x 2 test). Patients with tumors showing LOH of 16q had a worse prognosis than those without LOH according to Kaplan-Meier survival analysis (P=0.0158, log-rank test). In addition, LOH of 16q showed a significant relationship to prognosis by Cox regression analysis. Deletion mapping of 16q demonstrated that two regions (16q22.1 and 16q22.2-23.1) were frequently involved. Patients with 16q22.1 LOH had a poorer prognosis than those with intact 16q22.1 (P=0.0003, log-rank test). These findings suggest that gene(s) of which defect is possibly related to the aggressiveness of endometrial cancer are localized on a limited region of 16q that includes 16q22.1.

Human papillomavirus (HPV) has been identified in the majority of invasive cancers of the uterine cervix sampled and has been found to contribute in a significant way to the genesis of human cervical cancer. HPV has two transforming genes that encode the oncoproteins E6 and E7. E6 can form complexes with p53 and promote p53 degradation. We introduced wild-type p53 into a cervical cancer cell line via a recombinant adenoviral vector, Ad5CMV- p53. Human cervical cancer cell line HeLa, which has HPV type 18 and wild-type p53, was used in this study. Cells were grown in RPMI medium supplemented with 10% heat-inactivated fetal bovine serum. Ad5CMV- p53 was created by inserting the cytomegalovirus promoter, wild-type p53 cDNA, and SV40 polyadenylation signal in a minigene cassette into the E1-deleted region of the modified Ad5 adenovirus. The transduction efficiency was 100% when a dose ensuring a multiplicity of infection of 100 or greater was used. The p53 protein was detected in Ad5CMV- p53 -infected cells by immunohistochemical and Western blot analyses. The growth of the Ad5CMV- p53 -infected cells was greatly suppressed as detected by both cell count and [ 3 H]thymidine incorporation assay. These data suggest that transfection of HPV-positive cervical cancer cells with a wild-type p53 gene in a form such as Ad5CMV- p53 is a potential novel therapy for cervical cancer.

Background. Alterations of the p53 gene are involved in the development of diverse human malignancies, but their incidence and clinicopathologic features are still not well characterized for endometrial carcinoma. Methods. To investigate the clinicopathologic significance of p53, mutations and loss of heterozygosity (LOH) in endometrial carcinoma in 92 patients with this disease were examined. Results. Mutations of p53 were detected in 20 (22%) of the 92 patients with carcinoma, and LOH was detected in 23 (32%) of the 72 patients in whom heterozygosity of the gene was available. There was a significant correlation between the occurrence of mutation and LOH. Mutations and LOH were more frequent in patients with Grade 3 tumors than in those with Grades 1 and 2 tumors (P = 0.0498, P = 0.0051, respectively). Patients with LOH had a poorer postoperative survival than those without LOH (P = 0.0022, log-rank test), and patients with both LOH and mutation showed the worst prognosis (P < 0.0001, log rank test). Loss of heterozygosity of the p53 gene showed a significant relation to prognosis that was independent of tumor stage, histologic grade, and muscular invasion. Conclusions. Mutation and LOH of the p53 gene are prognostic indicators in patients with endometrial carcinoma, suggesting that alterations of p53 may play an important role in the development of this cancer.

Although various therapies are available to treat cancers, including surgery, chemotherapy, and radiotherapy, cancer has been the leading cause of death in Japan for the last 30 years, and new therapeutic modalities are urgently needed. As a new modality, there has recently been great interest in oncolytic virotherapy, with measles virus being a candidate virus expected to show strong antitumor effects. The efficacy of virotherapy, however, was strongly limited by the host immune response in previous clinical trials. To enhance and prolong the antitumor activity of virotherapy, we combined the use of two newly developed tools: the genetically engineered measles virus (MV-NPL) and the multilayer virus-coating method of layer-by-layer deposition of ionic polymers. We compared the oncolytic effects of this polymer-coated MV-NPL with the naked MV-NPL, both in vitro and in vivo. In the presence of anti-MV neutralizing antibodies, the polymer-coated virus showed more enhanced oncolytic activity than did the naked MV-NPL in vitro. We also examined antitumor activities in virus-treated mice. Complement-dependent cytotoxicity and antitumor activities were higher in mice treated with polymer-coated MV-NPL than in mice treated with the naked virus. This novel, polymer-coated MV-NPL is promising for clinical cancer therapy in the future.

The transduction efficacy of adenovirus serotype 5 (Ad5) vector in high-grade human bladder cancer cells is generally extremely low due to the non-expression of coxsackie and adenoviral receptor (CAR). We investigated whether fiber-modified adenovirus vector containing an RGD motif in the HI loop of the adenovirus fiber knob could increase the transduction efficiency of Ad5 into human bladder cancer cells in vitro.We examined the expressions of CAR, and of α(v), β(3) and β(5) integrin, and the transduction efficacy of fiber-modified adenovirus vector in four human bladder cancer cell lines (TCC-SUP, 253J, T24 and KK47).The expression of CAR was lower and those of α(v) and β(3) integrin were higher in four human cancer cell lines compared with the control cell line, KK47. The transduction efficacy of fiber-modified adenovirus vector increased by 20- to 470-fold compared with Ad5.Fiber-modified adenovirus vector may be useful in order to establish new effective gene therapy strategies for the treatment of high-grade human bladder cancer.

The present study aimed to evaluate the efficacy and toxicities of nadaplatin-based concurrent chemoradiotherapy (CCRT) in patients with stage IIA to IVA cervical carcinoma. Patients with an International Federation of Gynecology and Obstetrics (FIGO) stage IIA to IVA cervical carcinoma were treated with nadaplatin-based CCRT, using high-dose rate intracavitary brachytherapy (HDR-ICBT) or radiotherapy (RT) alone, in patients with FIGO stage IIA to IVA cervical carcinoma. CCRT with nedaplatin (80 mg/m2) was administered on Days 1 and 29. The records of 17 women treated either with nadaplatin-based CCRT using HSR-ICBT (n=8) or RT alone (n=9), for stage IIA to IVA cervical carcinoma were retrospectively reviewed. The activity and toxicity were compared in the two treatment groups. Progression-free survival (PFS) and overall survival (OS) were the main endpoints. The 5-year overall survival rates in the CCRT and RT groups were 68.6 and 77.8%, respectively. The median OS of the CCRT and RT groups was 38.5 and 27.3 months, respectively. There was no significant difference in either PFS (P=0.618) or OS (P= 0.231). The most common grade 3–4 or higher toxicities in the CCRT groups were leuko-/neutropenia (37.5%). The frequency of acute grade 3–4 toxicity was higher in the CCRT compared to the RT group. However, no statistically significant difference was observed. Nedaplatin-based CCRT was safely performed. Although the prognosis of patients with FIGO stage IIA to IVA cervical carcinoma was not significantly improved, fewer distant relapses were observed in this treatment. Consequently, nedaplatin-based CCRT may be considered as a potential alternative to cisplatin-based CCRT in this patient population.

Although replication-competent viruses have been developed for treating cancers, their cytotoxic effects are insufficient as a result of infection inhibited by the generation of neutralizing antibodies, and systemic administration is difficult as a result of the life-threatening serious side-effects of virus-induced cytokine surge. To overcome these critical problems, we devised a plasmid/polycation/polyanion complex and assessed the potential of ternary plasmid complexes coated with chondroitin sulfate in gene therapy for ovarian cancer. The antitumor effects of chondroitin sulfate-coated complex as an anionic component were compared with those of hyaluronic acid on ovarian cancer.Plasmid harboring the gene of murine granulocyte macrophage-colony-stimulating factor (mGM-CSF) was complexed with polyethyleneimine (PEI) and hyaluronic acid or chondroitin sulfate. Murine ovarian cancer cells were injected into (C57BL/6 × C3H/He) F(1) mice to prepare a subcutaneous or intraperitoneal tumor model.DNA/PEI was charged positively and DNA/PEI/chondroitin sulfate or DNA/PEI/hyaluronic acid was charged negatively. Plasmid-green fluorescent protein (GFP)/PEI coated with 10-kilodalton (kDa) chondroitin sulfate increased transfection efficiency compared to coating with chondroitin sulfate of higher-molecular-weight or hyaluronic acid. The transfection efficiency of GFP/PEI/10-kDa chondroitin sulfate in ovarian cancer cells was six-fold higher than that in normal cells. Intraperitoneal injection of mGM-CSF/PEI coated with 10-kDa chondroitin sulfate prolonged survival compared to that coated with hyaluronic acid. Intratumoral injection of mGM-CSF/PEI coated with 10-kDa chondroitin sulfate achieved mouse survival rates of 100%, although that with hyaluronic acid did not.These findings suggest that GM-CSF/PEI coated with 10-kDa chondroitin sulfate has the potential for use in gene therapy of ovarian cancer.

Although cancer therapy using replication-selective oncolytic adenoviruses has been available for many years, its anti-tumor efficacy is suboptimal as a result of low and nonspecific infectivity that depends on coxsackie adenovirus receptor expression of the target cancer and normal cells, and generation of an anti-adenovirus neutralizing antibody. In addition, concerns of triggering a severe innate immune response against the adenovirus limit the systemic administration. We developed the carrier cell-based oncolytic virus system (CBOVS) using irradiated tumor cells as carrier cells and concealing the adenovirus (Ad-IAI.3B) inside to improve the specific infectivity. We investigated the anti-tumor effect of CBOVS in a multiple lung tumor mouse model.The ability of CBOVS to infect Ad-IAI.3B to the target cancer cells was examined in vitro in the presence of anti-adenovirus antibodies. To evaluate the systemic effect of CBOVS, we intravenously injected CBOVS into mice with lung tumors (KLN205 cell lines).CBOVS enhanced the infectivity of Ad-IAI.3B to tumor cells in the presence of anti-adenovirus antibodies in vitro. Intravenous injections of CBOVS produced an accumulation of the adenovirus in the lung-bearing tumors and produced a strong anti-tumor effect in vivo. Furthermore, lymphocytes collected from the CBOVS-treated mice induced an increase in cytokines related to the Th1 response (interferon-γ, interleukin-12) by pulsing with KLN205.These findings suggest that CBOVS could protect adenoviruses from neutralizing antibodies and systemically deliver them to lung tumors. Furthermore, CBOVS appears to have potential as a tumor cell vaccine that activates cytotoxic immunity against cancer cells.

The oncolytic virus is expected to proliferate in and destroy tumor cells. The virus is also thought to generate antitumor immunity. Virally infected tumor cells express viral antigens on their surfaces. Such tumor cells or their fragments would be taken up by antigen-presenting cells (APCs) together with tumor-associated antigens (TAAs), and facilitated cross-priming of tumor-specific T cells. Virus-specific protein presented on the infected cells therefore played a crucial role in the enhancement of the adaptive antitumor immunity. In this study, a plasmid encoding adenovirus protein, the adenovirus death protein (ADP), was constructed, and a very fine complex of the plasmid with polyethylenimine (PEI) and chondroitin sulfate (CS) was injected into tumor-bearing mice. Transfection of the ADP gene was shown to suppress tumor growth as effectively as granulocyte-macrophage colony-stimulating factor (GM-CSF) transfection. When mice were administered plasmid coding ADP (pDNA-ADP) to generate an immune response to ADP prior to therapy, transfection of the ADP gene induced a much higher level of tumor growth suppression than that found in the non-immunized mice. An evident synergistic effect of ADP and GM-CSF genes was also observed, and at a pDNA-ADP/pDNA-GM-CSF ratio of 4:1, significant suppression of tumor growth was achieved even in the non-immunized mice.

Although replication-competent oncolytic viral vectors have been developed to improve antitumor activity, the generation of high titers of neutralizing antibodies inhibits repetitive viral infection. Many studies have reported that oncolytic virus-infected carrier cells can overcome this viral induced immunogenicity. However, the effects of oncolytic virus-infected carrier cells in human oral squamous cell carcinoma (OSCC) have not yet been examined. In the present study, simulating the clinical trial, we examined the antitumor activity of carrier cells infected with oncolytic adenovirus AdE3-IAI.3B in human OSCC. IAI.3B was highly activated in OSCC cells but not in normal cells. AdE3-IAI.3B killed OSCC cells in vitro but not normal cells. AdE3-IAI.3B-infected A549 carrier cells eradicated OSCC GFP-SAS tumors in nude mice. Anti-adenovirus neutralizing antibodies completely blocked the antitumor effect of AdE3-IAI.3B but did not block that of carrier cells. After the induction of anti-adenoviral CTL responses by immunization of adenovirus, administration of carrier cells induced complete regression of murine squamous cell carcinoma SCC7 tumors. Adenovirus-GM-CSF augmented the antitumor effect of carrier cells. The IAI.3B-driven oncolytic adenovirus-infected carrier cell system might prove useful in the treatment of OSCC and clinical trials of it should be conducted in the near future.

Layer-by-layer deposition of the ionic polymers onto adenovirus particles afforded the multilayer-coated virus vectors. The infectivity of the virus in the presence of anti-adenovirus antibody increased as the layer number and the viruses with five or six polymer layers allowed relatively high efficiency of reporter gene expression in vitro. Therapeutic effect of the intraperitoneal injection of the oncolytic adenovirus with quintal polymer multilayers on the mice bearing intraperitoneal metastatic ovarian cancer was examined. All the control mice injected with PBS died within 21 days after the tumor inoculation. On the other hand, the mice injected with the multilayer-coated oncolytic virus lived much longer and seven eighths of them lived60 days without apparent accumulation of ascites. These approaches would open a new way to create a novel, safe and efficient viral gene therapy.

The highest barriers for non-viral vectors to an efficient in vivo gene transfection would be (1) non-specific interaction with biological molecules, and (2) large size of the DNA complex particles. Protective coating of the DNA/polyethyleneimine (PEI) complexes by hyaluronic acid (HA) effectively diminished the adverse interactions with biological molecules. Here we found HA also protected the DNA/PEI complexes against aggregation and inactivation through lyophilization-and-rehydration procedures. It allows us to prepare the concentrated very small DNA complex particles (

The transduction efficacy of adenovirus serotype 5 (Ad5) vector in human renal carcinoma cells is generally extremely low due to the non-expression of Coxsackie and adenoviral receptor (CAR). We investigated whether fiber-modified Ad vector containing an RGD motif in the HI loop of the Ad fiber knob could increase the transduction efficiency of Ad5 in human renal carcinoma cells in vitro.We examined both expressions of CAR, and alpha(v), beta(3) and beta(5) integrins, and the transduction efficacy of fiber-modified adenovirus vector in all cell lines.The expression of CAR was lower and those of alpha(v) and beta(3) integrins were higher in all cell lines compared with control cell line, KK47. The transduction efficacy of fiber-modified Ad vector increased by 125- to 1,800-fold compared with Ad5.The fiber-modified Ad vector may be useful to establish effective new gene therapy strategies for the treatment of renal cell carcinoma.

The squamous cell carcinoma antigen (SCCA) serves as a serological marker for squamous cell carcinomas. Molecular cloning of the SCCA genomic region has revealed the presence of two tandemly arrayed genes, SCCA1 and SCCA2. We examined the promoter activity of the 5'-flanking proximal region of the SCCA1 gene. Deletion analysis of SCCA1 promoter identified a 175-bp core promoter region and an enhancer region at -525 to -475 bp upstream of the transcription start site. The transcriptional activity of the SCCA1 promoter was up-regulated in squamous cell carcinoma cells, compared with normal keratinocyte, normal non-keratinocyte and adenocarcinoma cells. Five tandem repeats of enhancer increased SCCA1 promoter activity by 4-fold. Oncolytic adenovirus driven by the SCCA1 promoter with 5 tandem repeats of enhancer specifically killed squamous cell carcinoma cells in vitro and in vivo. A549 carrier cells infected with the oncolytic adenovirus induced complete regression of tumor by overcoming immunogenicity and adenovirus-mGM-CSF augmented the antitumor effect of carrier cells. These findings suggest that SCCA1 promoter is a potential target of gene therapy for squamous cell carcinoma.

Objective To explore the potential clinical application of the oncolytic activity of cyclooxygenase 2 (COX-2) promoter–based, conditional, replication-selective adenovirus vector for hypopharyngeal squamous cell carcinoma. Design In vivo study and retrospective study. Setting Kobe University Hospital, Kobe, Japan. Subjects Expression of COX-2 in hypopharyngeal cancers treated at Kobe University Hospital was immunohistochemically investigated. In addition, nude mice bearing human hypopharyngeal cancer cells (H891) were used to analyze oncolytic activity of a conditional replication-selective adenovirus vector in which the expression of E1a , required for viral replication, is controlled by the COX-2 promoter Ad-COX2-E1a. Results In vivo assays showed significant growth suppression in the murine hypopharyngeal model. Cyclooxygenase 2 expression was observed in 75.3% of hypopharyngeal cancers, especially in differentiated tumor cells ( P = .001; r = 0.433). Conclusion In this study, we demonstrated the potential of oncolytic therapy using the COX-2–promoter based, conditional, replication-selective adenovirus for COX-2–expressing hypopharyngeal squamous cell carcinomas.

OBJECTIVES Cyclooxygenase-2 (COX-2) is highly expressed in several human cancers, including bladder cancer. Thus, a selective COX-2 inhibitor could be useful as an antitumor agent for a range of cancers. In the present study, we investigated the antitumor effect and E-cadherin induction of etodolac, a highly selective COX-2 inhibitor, on human bladder cancer cells in vitro and in vivo. METHODS We examined the cytotoxicity of etodolac against three human bladder cancer cell lines, T24, 5637, and KK47, and performed quantitative reverse transcriptase-polymerase chain reaction to measure the mRNA expression of COX-2, and E-cadherin. RESULTS Etodolac showed significant cytotoxicity only to T24 cells, which expressed the greatest level of COX-2 mRNA and the lowest level of E-cadherin mRNA among the three cell lines. Etodolac also increased the E-cadherin mRNA expression in T24 cells in vitro. We also found that etodolac suppressed tumor growth and induced E-cadherin expression and cell apoptosis in a T24 tumor xenograft mouse model. CONCLUSIONS Etodolac exhibited antitumor activity and induced E-cadherin expression in bladder cancer cells and might be useful for the clinical treatment and prevention of bladder cancer, especially in poorly differentiated bladder cancer with high COX-2 and low E-cadherin expression.

Although replication-competent viruses have been developed to treat cancers, their cytotoxic effects are insufficient, as infection is inhibited by the generation of neutralizing antibodies. To address this limitation, we developed a carrier cell system to deliver a replication-competent adenovirus. Carrier cells infected with replication-competent adenovirus were incubated with target cancer cells in a high titer of anti-adenovirus antibody. Carrier cells were injected into syngeneic subcutaneous tumors after immunization with adenovirus. Carrier cell–derived cell fragments containing viral particles were engulfed by proliferative target cancer cells. This engulfment-mediated transfer of adenovirus was not inhibited by the anti-adenovirus antibody and enabled repetitive infection. After the induction of anti-adenoviral cytotoxic T-lymphocyte (CTL) responses by immunization with adenovirus, administration of carrier cells infected with a replication-competent adenovirus induced complete tumor regression. Adenovirus-GM-CSF augmented the anti-tumor effect of carrier cells by increasing anti-adenoviral and anti-tumoral CTL responses and decreased the number of injections of carrier cells required to induce complete tumor regression. This novel carrier cell–mediated viral transfection system might prove useful in a variety of cancer therapies.

Background: Although there have recently been much progress in cancer treatment including surgery, chemotherapy and radiotherapy, cancers have long been the leading cause of death in Japan in the last 30 years and the development of new therapeutic modalities is imminently required. As a new modality, there has recently been great interest in oncolytic virotherapy. Particularly, measles virus is one of the candidate viruses expected for strong antitumor effects. The efficacy of virotherapy, however, was strongly limited by the immune response of the host in previous clinical trials.Methods: To enhance and prolong the antitumor activity of the virotherapy in vivo, we combined newly developed tools of the genetically engineered measles virus (MV-NPL) and multilayer virus coating method of layer-by-layer deposition of ionic polymers. We compared the oncolytic effects of this polymer-coated MV-NPL with naked MV-NPL in vitro and in vivo.Results: In the presence of anti-MV neutralizing antibodies, the polymer-coated virus showed more enhanced oncolytic activity than naked MV-NPL in vitro. We also examined the antitumor immunity in virus treated mice. Complement-dependent cytotoxicity activities in mice treated with polymer-coated MV-NPL were higher than those with naked virus and stronger antitumor activity was observed in these mice.Conclusion: This novel polymer-coated MV-NPL may be promising for future clinical cancer therapy.

Objective In most cervical cancers, human papillomaviruses (HPVs) are identified. The E6 and E7 genes of HPVs encode proteins, that interfere with the function of the tumor suppressor proteins p53 and Rb. We are exploring the potential use of antisense HPV RNA transcripts for gene therapy for HPV-positive cervical cancers. Methods Via a recombinant adenoviral vector, Ad5CMV- HPV 16 AS , we introduced the antisense RNA transcripts of the E6 and E7 genes of HPV type 16 into human cervical cancer SiHa cells harboring HPV 16. We then analyzed the effects of expression of these genes on cell and tumor growth. Results HPV 16 E6/E7 antisense RNA was detected for 14 days in Ad5CMV- HPV 16 AS -infected cells. After infection, E6 and E7 protein expression was suppressed, and p53 and Rb protein expression increased. The Ad5CMV- HPV 16 AS -infected cells underwent apoptosis in vitro and in vivo. Cell growth and tumorigenicity were greatly suppressed. Ad5CMV- HPV 16 AS treatment significantly reduced the volumes of established subcutaneous tumors. Conclusion Transfection of cervical cancer cells with HPV 16 E6/E7 antisense RNA in a form such as Ad5CMV- HPV 16 AS might be a potentially useful approach to the therapy of HPV 16-positive cervical cancer.