Search

Human pluripotent stem cells, such as embryonic stem cells and induced pluripotent stem cells, have the potential to differentiate into a wide variety of cells in vitro and have applications in basic developmental biology research and regenerative medicine. To understand the process of differentiation from pluripotent stem cells to functional cells, it is necessary to efficiently and safely transfer and express exogenous genes. We attempted to optimize the efficient transfer of genes into pluripotent stem cells using adenoviral vectors. Comparative study of the activities of three representative ubiquitously active promoters revealed that only the CA promoter allowed robust transgene expression in human pluripotent stem cells. In addition, we established a protocol that allowed us to efficiently introduce target genes and ensure their expression even in small numbers of cells. Adenoviral vector infection of pluripotent stem cells in single-cell suspension culture yielded high gene transfer efficiency with low cytotoxicity, without losing the undifferentiated state of the pluripotent stem cells. This optimized system will facilitate developmental biology research and regenerative medicine using pluripotent stem cells.

Aims Hepatocyte growth factor (HGF) is a multifunctional cytokine that plays important roles in pancreatic physiology. Approvals of gene therapy drugs have highlighted gene therapy as an innovative new drug modality, but the very recent reports of deaths in clinical trials have provided a warning that high-dose gene therapy can cause dangerous liver toxicity. The present study aimed to develop a safe and low-dose but therapeutically effective adenovirus-mediated HGF gene therapy for streptozotocin (STZ)-induced type 1 diabetes (T1D) in mice. Main methods A single intravenous injection of a low dose (3 × 108 plaque forming units) of adenoviral vector expressing the HGF gene under the transcriptional control of a strong promoter, i.e., the cytomegalovirus immediate-early enhancer and a modified chicken β-actin promoter (Ad.CA-HGF), was given to T1D mice. Key findings Low-dose HGF gene therapy significantly attenuated the elevation of blood glucose concentrations at the acute phase of T1D, and this effect persisted for several weeks. Temporal upregulation of plasma insulin at the acute phase was maintained at a normal level in Ad.CA-HGF-treated mice, suggesting that the therapeutic mechanism may involve protection of the remaining β-cells by HGF. Liver enzymes in plasma were not elevated in any of the mice, including the Ad.CA-HGF-treated animals, all of which looked healthy, suggesting the absence of lethal adverse effects observed in patients receiving high intravenous doses of viral vectors. Significance A low dose of intravenous Ad-mediated HGF gene therapy is clinically feasible and safe, and thus represents a new therapeutic strategy for treating T1D.

Rett syndrome (RTT) is a neurodevelopmental disorder mainly caused by mutations in the gene encoding the transcriptional regulator Methyl-CpG-binding protein 2 (MeCP2), located on the X chromosome. Many RTT patients have breathing abnormalities, such as apnea and breathing irregularity, and respiratory infection is the most common cause of death in these individuals. Previous studies showed that MeCP2 is highly expressed in the lung, but its role in pulmonary function remains unknown. In this study, we found that MeCP2 deficiency affects pulmonary gene expression and structures. We also found that Mecp2-null mice, which also have breathing problems, often exhibit inflammatory lung injury. These injuries occurred in specific sites in the lung lobes. In addition, polarizable foreign materials were identified in the injured lungs of Mecp2-null mice. These results indicated that aspiration might be a cause of inflammatory lung injury in Mecp2-null mice. On the other hand, MeCP2 deficiency affected the expression of several neuromodulator genes in the lower brainstem. Among them, neuropeptide substance P (SP) immunostaining was reduced in Mecp2-null brainstem. These findings suggest that alteration of SP expression in brainstem may be involved in autonomic dysregulation, and may be one of the causes of aspiration in Mecp2-null mice.

Human pluripotent stem cells (hPSCs) are a promising source of regenerative material for clinical applications. However, hPSC transplant therapies pose the risk of teratoma formation and malignant transformation of undifferentiated remnants. These problems underscore the importance of developing technologies that completely prevent tumorigenesis to ensure safe clinical application. Research to date has contributed to establishing safe hPSC lines, improving the efficiency of differentiation induction, and indirectly ensuring the safety of products. Despite such efforts, guaranteeing the clinical safety of regenerative medicine products remains a key challenge. Given the intrinsic genome instability of hPSCs, selective growth advantage of cancer cells, and lessons learned through failures in previous attempts at hematopoietic stem cell gene therapy, conventional strategies are unlikely to completely overcome issues related to hPSC tumorigenesis. Researchers have recently embarked on studies aimed at locating and directly treating hPSC-derived tumorigenic cells. In particular, novel approaches to directly killing tumorigenic cells by transduction of suicide genes and oncolytic viruses are expected to improve the safety of hPSC-based therapy. This article discusses the current status and future perspectives of methods aimed at directly eradicating undifferentiated tumorigenic hPSCs, with a focus on viral vector transduction., Graphical Abstract

Background Adult T-cell leukemia/lymphoma (ATL) is a peripheral T-cell malignancy caused by long-term human T-cell leukemia virus type I (HTLV-1) infection. Survivin-responsive, conditionally replicating adenoviruses regulated by multiple tumor-specific factors (Surv.m-CRAs), in which the expression of the adenoviral early region 1A gene is regulated by the survivin (BIRC5) promoter, can be used to treat several cancers. As survivin is overexpressed in ATL, we examined the effects of Surv.m-CRAs on ATL-selective replication and survival. Methods We tested two ATL cell lines and four HTLV-1-infected T-cell lines. The cells were subjected to infection with either E1-deleted, replication-defective adenoviruses or Surv.m-CRAs at various multiplicities of infection. Results Strong activation of survivin promoter was observed in all six cell lines. Moreover, the expression of the coxsackie and adenovirus receptor (CAR), which is important for adenoviral infection, was high in the cell lines. In contrast, we observed the absence of survivin promoter activity and a low expression of CAR in activated peripheral blood lymphocytes (PBLs) from healthy subjects. Surv.m-CRAs actively replicated and induced cytocidal effects in five out of six cell lines; conversely, we observed minimal viral replication and no marked cytotoxicity in normal activated PBLs. Conclusions This is the first report demonstrating that Surv.m-CRAs constitute attractive potential anti-ATL agents.

11512 Background: Whereas one of oncolytic viruses (OVs), inducing selective tumor killing and systemic anti-tumor immunity, was approved by FDA in 2015, the best OV that more safely and efficiently treats intractable cancers has not been successfully developed. By our platform technology to efficiently construct next-generation OVs, i.e., “conditionally replicating adenoviruses (CRAs) that target and/or treat tumor cells with multiple factors” (m-CRAs), we identified that among candidates, survivin-responsive m-CRAs (Surv.m-CRAs) exhibited the most potent antitumor efficacy and cancer selectivity ( i.e., safety) in preclinical studies ( Cancer Res, 2005 et al.). Here we present the data of First-In-Human phase I clinical trial of Surv.m-CRA-1 for musculoskeletal tumors (MST). Methods: This single-arm, open label study included 9 patients with unresectable and advanced MST. Patients underwent a single intratumoral injection of either 1×10^10 viral particle (vp) (low), 1×10^11 vp (mid) or 1×10^12 vp (high). The primary endpoints were safety and tolerability. The secondary endpoints included the local control of treated tumor at one month, defined by RECIST and Choi criteria, analysis of dissemination of Surv.m-CRA-1, serum cytokine and adenoviral antibody. Long-term follow-up was done in some patients. Results: Four patients (44.4%) had grade 3 or higher adverse events, including lymphopenia, leukocytopenia and mildly elevated liver transaminase in 2, 1 and 1 patient, respectively. Virus excretions, including second peak of viremia from viral replication in tumor, were observed in 1, 2 and 3 patients of low, mid and high dose, respectively. Out of 9 patients, 5 PR, 3 SD and 1 PD by Choi, and 8 SD and 1 PD by RECIST were observed. During follow-up, another 1 and 2 patients became PR by Choi and RECIST, respectively. Of note, long-term PR (over 2 years) after a single injection of Surv.m-CRA-1 was achieved in two chordoma cases in low dose. Conclusions: Surv.m-CRA-1 was well tolerated and showed antitumor activity for prolonged periods against advanced MST. We about to start Phase I/II study of multiple injections of Surv.m-CRA-1 for advanced solid tumors in two-arms for musculoskeletal tumors and pancreatic cancer. Clinical trial information: R000026464 .

The risk of tumor formation poses a challenge for human pluripotent stem cell (hPSC)-based transplantation therapy. Specific and total elimination of tumorigenic hPSCs by suicide genes has not been achieved because no methodology currently exists for testing multiple candidate transgene constructs. Here, we present a novel method for efficient generation of tumorigenic cell-targeting lentiviral vectors (TC-LVs) with diverse promoters upstream of a fluorescent protein and suicide genes. Our two-plasmid system achieved rapid and simultaneous construction of different TC-LVs with different promoters. Ganciclovir exerted remarkable cytotoxicity in herpes simplex virus thymidine kinase (HSV-tk)-transduced hPSCs, and high specificity for undifferentiated cells was achieved using the survivin promoter (TC-LV.Surv). Moreover, ganciclovir treatment completely abolished teratoma formation by TC-LV.Surv-infected hPSCs transplanted into mice, without harmful effects. Thus, TC-LV can efficiently identify the best promoter and suicide gene for specific and complete elimination of tumorigenic hPSCs, facilitating the development of safe regenerative medicine. This article is protected by copyright. All rights reserved.

Inflammatory bowel disease (IBD) severely affects the quality of life of patients. At present, there is no clinical solution for this condition; therefore, there is a need for innovative therapies for IBD. Hepatocyte growth factor (HGF) exerts various biological activities in various organs. However, a clinically applicable and effective HGF-based therapy for IBD has yet to be developed. In this study, we examined the therapeutic effect of injecting an adenoviral vector encoding the human HGF gene (Ad.HGF) into the hindlimbs of mice with dextran sodium sulfate (DSS)-induced colitis. Plasma levels of circulating human HGF (hHGF) were measured in injected mice. The results showed that weight loss and colon shortening were significantly lower in Ad.HGF-infected mice as compared to control (Ad.LacZ-infected) colitic mice. Additionally, inflammation and crypt scores were significantly reduced in the entire length of the colon, particularly in the distal section. This therapeutic effect was associated with increased cell proliferation and an antiapoptotic effect, as well as a reduction in the number of CD4+ cells and a decreased CD4/CD8 ratio. The levels of inflammatory, as well as Th1 and Th2 cytokines were higher in Ad.HGF-infected mice as compared to the control colitic mice. Thus, systemically circulating hHGF protein, produced by an adenovirally transduced hHGF gene introduced at distal sites in the limbs, significantly ameliorated DSS-induced colitis by promoting cell proliferation (i.e., regeneration), preventing apoptosis, and immunomodulation. Owing to its clinical feasibility and potent therapeutic effects, this method may be developed into a clinical therapy for treating IBD.

The precise roles of tetraspanin CD9 are unclear. Here we show that CD9 plays a stimulus-independent role in angiogenesis and that inhibiting CD9 expression or function is a potential antiangiogenic therapy. Knocking down CD9 expression significantly inhibited in vitro endothelial cell migration and invasion induced by vascular endothelial growth factor (VEGF) or hepatocyte growth factor (HGF). Injecting CD9-specific small interfering RNA (siRNA-CD9) markedly inhibited HGF- or VEGF-induced subconjunctival angiogenesis in vivo. Both results revealed potent and stimulus-independent antiangiogenic effects of targeting CD9. Furthermore, intravitreous injections of siRNA-CD9 or anti-CD9 antibodies were therapeutically effective for laser-induced retinal and choroidal neovascularization in mice, a representative ocular angiogenic disease model. In terms of the mechanism, growth factor receptor and downstream signaling activation were not affected, whereas abnormal localization of integrins and membrane type-1 matrix metalloproteinase was observed during angiogenesis, by knocking down CD9 expression. Notably, knocking down CD9 expression did not induce death and mildly inhibited proliferation of quiescent endothelial cells under conditions without an angiogenic stimulus. Thus, CD9 does not directly affect growth factor-induced signal transduction, which is required in angiogenesis and normal vasculature, but is part of the angiogenesis machinery in endothelial cells during angiogenesis. In conclusion, targeting CD9 produced stimulus-independent antiangiogenic effects predominantly in activated endothelial cells during angiogenesis, and appears to be an effective and safe antiangiogenic approach. These results shed light on the biological roles of CD9 and may lead to novel antiangiogenic therapies.

Mutations in methyl-CpG-binding protein 2 (MeCP2) gene cause the neurodevelopmental disorder Rett syndrome (RTT). Here, we describe a new experimental system that efficiently elucidates the role of MeCP2 in neural development. MeCP2-null and control ES cells were generated by adenoviral conditional targeting and examined for maintenance of the undifferentiated ES cell state, neurogenesis, and gliogenesis during in vitro differentiation. In addition, dopamine release and electrophysiological features of neurons differentiated from these ES cells were examined. Loss of MeCP2 did not affect undifferentiated ES cell colony morphology and growth, or the timing or efficiency of neural stem cell differentiation into Nestin-, TuJ- or TH-positive neurons. In contrast, gliogenesis was drastically accelerated by MeCP2 deficiency. Dopamine production and release in response to a depolarizing stimulus in MeCP2-null ES-derived dopaminergic neurons was intact. However, MeCP2-null differentiated neurons showed significantly smaller voltage-dependent Na(+) currents and A-type K(+) currents, suggesting incomplete maturation. Thus, MeCP2 is not essential for maintenance of the undifferentiated ES cell state, neurogenesis, or dopaminergic function; rather, it is principally involved in inhibiting gliogenesis. Altered neuronal maturity may indirectly result from abnormal glial development and may underlie the pathogenesis of RTT. These data contribute to a better understanding of the developmental roles of MeCP2 and the pathogenesis of RTT.

[Background] Recent approvals of oncolytic virus (OV) by FDA and EMA attract the worldwide oncologists and anticancer market. We developed the first platform technology to efficiently construct diverse types of a next-generation conditionally replicating adenovirus (CRA), i.e., CRAs that target and/or treat tumor cells with multiple factors (m-CRAs), which can increase tumor-specificity (i.e., safety) and efficacy (Gene Ther 2005). Using this platform technology, we have generated and tested numbers of m-CRAs as anticancer agents, and found that one of the best was survivin-responsive m-CRAs (Surv.m-CRAs). In preclinical studies, Surv.m-CRAs induced more potent cytotoxic effects against most of malignant tumors than other competing CRAs, and exhibited not only stronger but also more cancer-selective phenotypes than telomerase reverse transcriptase (Tert)-responsive m-CRAs (Cancer Res 2005). Moreover, Surv.m-CRAs induced increased effectiveness against cancer stem cells, which are resistant to conventional therapies (J Trans Med 2014). Preclinical analyses suggested that Surv.m-CRA is the “best-in class” CRA. [Trial protocol] We submitted an IND in March, 2016 and have been performing the first-in-human investigator-initiated ICH-GCP clinical trial for refractory malignant bone and soft tissue tumors (Phase I). Three doses (low: 1×10^10 viral particle [vp], mid: 1×10^11 vp, high: 1×10^12 vp) are planned. Adverse effects were graded according to CTCAE v4.0. Viral shedding into blood, urine and saliva was monitored by PCR. Efficacy was assessed by CT according to RECIST and Choi criteria. [Results] Three patients underwent a single intratumoral injection of low dose Surv.m-CRA-1. Treatment-related adverse events included asymptomatic and temporal leukopenia (grade 3, n=1), CPK elevation (grade 1, n=1), fever (grade 1, n=1) or other mild events (no grade 4 events). Viral shedding into saliva was found in the first case only at 3 hours after injection and was negative in other two cases. Clinical efficacy for target lesion was observed in all three cases (PR or better). First case showed PR by Choi criteria at 4 weeks and PR by RECIST (reduction rate, 50%) at 28 weeks; surprisingly the antitumor efficacy continued for more than one year. In the second case, tumor necrosis (PR by Choi criteria) was found at 4 weeks and subsequently, bone formation (beneficial remodeling) was observed at 12 weeks after the injection. Since no DLT was observed in the low dose cohort, we started mid dose treatment. [Conclusions] First-in-human trial of Surv.m-CRA-1 demonstrated drastic and long-term antitumor effects only by a sinle injection of only 1/100 of the predicted maximal dose. Thus, the potential of “best-in-class” Surv.m-CRA-1 is, at least in part, being reproduced in clinical trial. After finishing the phase I study, we will proceed Phase I/II study of multiple injections for advanced solid tumors. Citation Format: Satoshi Nagano, Toshitaka Futagawa, Eriko Sumi, Nobuhiro Ijichi, Munekazu Yamaguchi, Masanori Nakajo, Teruto Hashiguchi, Yasuo Takeda, Takashi Yoshiura, Akira Shimizu, Muneo Takatani, Setsuro Komiya, Ken-ichiro Kosai. Phase I study of potentially "best-in-class" survivin-responsive conditionally replicating adenovirus for advanced sarcoma actually demonstrates potent and long-term efficacy and high safety [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT122.

We hypothesized that therapy, composed of antiapoptotic soluble Fas (sFas) gene transfer, combined with administration of the cardioprotective cytokine granulocyte colony-stimulating factor (G-CSF), would markedly mitigate cardiac remodeling and dysfunction following myocardial infarction (MI). On the 3rd day after MI induced by ligating the left coronary artery in mice, four different treatments were initiated: saline injection (Group C, n = 26); G-CSF administration (Group G, n = 27); adenoviral transfer of sFas gene (Group F, n = 26); and the latter two together (Group G+F, n = 26). Four weeks post-MI, Group G+F showed better survival than Group C (96 vs. 65%, P < 0.05) and the best cardiac function among the four groups. In Group G, the infarct scar was smaller and less fibrotic, whereas in Group F the scar was thicker, without a reduction in area, and contained abundant myofibroblasts and vascular cells; Group G+F showed both phenotypes. G-CSF exerted a beneficial effect on infarct tissue dynamics through antifibrotic and proliferative effects on granulation tissue; however, it also exerts an adverse proapoptotic effect that leads to thinning of the infarct scar. sFas appeared to offset the latter drawback. In vitro study using cultured myofibroblasts derived from the infarct tissue revealed that G-CSF increased proliferating activity of those cells accompanying activation of Akt and signal transducer and activator of transcription 3, while accelerating Fas-mediated apoptosis with increasing Bax-to-Bcl-2 ratio. The results suggest that combined use of G-CSF administration and sFas gene therapy is a potentially powerful tool against post-MI heart failure.

1. In the present study, we examined the effects of inhibiting transforming growth factor (TGF)-beta in a mouse model of diabetic nephropathy. 2. An adenovirus harbouring the gene encoding soluble TGF-beta type II receptor (Ad.CAG-sTbetaRII), a competitive inhibitor of TGF-beta, was injected into hindlimb muscles (systemic delivery) of mice 5 weeks after the induction of diabetes with streptozotocin. The control group was injected with an adenovirus encoding the LacZ gene (Ad-LacZ). 3. Five weeks after administration, anti-TGF-beta gene therapy was found to have had no effect on renal function, albuminuria or glucose metabolism in mice with diabetic nephropathy. Nonetheless, this gene therapy did significantly reduce fibrosis in both glomeruli and renal tubules. These effects were accompanied by attenuation of the increased expression of alpha-smooth muscle actin normally seen in kidneys of diabetic mice and better preservation of glomerular cell numbers, although the thickness of the glomerular capillary basement membrane was unchanged. The plasma concentration of soluble TGF-beta type II receptor peaked on Day 7 after treatment, but was undetectable by Day 14. Moreover, a second treatment with Ad.CAG-sTbetaRII failed to prolong the interval of gene product expression in the blood. 4. The present anti-TGF-beta gene therapy showed a significant antifibrotic effect in a model of diabetic nephropathy, but failed to improve renal function. The inadequacy of the observed effect is likely due to the relatively short interval of gene product expression. This problem will have to be overcome if gene therapies for slowly progressing diseases, like diabetic nephropathy, are to be realised.

Hepatocyte growth factor (HGF) reportedly exerts beneficial effects on the heart following myocardial infarction and during nonischemic cardiomyopathy, but the precise mechanisms underlying the latter have not been well elucidated. We generated nonischemic cardiomyopathy in mice by injecting them with doxorubicin (15 mg/kg ip). Two weeks later, when cardiac dysfunction was apparent, an adenoviral vector encoding human HGF gene (Ad.CAG-HGF, 1×1011 particles/mouse) was injected into the hindlimb muscles; LacZ gene served as the control. Left ventricular dilatation and dysfunction normally seen 4 wk after doxorubicin administration were significantly mitigated in HGF-treated mice, as were the associated cardiomyocyte atrophy/degeneration and myocardial fibrosis. Myocardial expression of GATA-4 and a sarcomeric protein, myosin heavy chain, was downregulated by doxorubicin, but the expression of both was restored by HGF treatment. The protective effect of HGF against doxorubicin-induced cardiomyocyte atrophy was confirmed in an in vitro experiment, which also showed that neither cardiomyocyte apoptosis nor proliferation plays significant roles in the present model. Upregulation of c-Met/HGF receptor was noted in HGF-treated hearts. Among the mediators downstream of c-Met, the activation of extracellular signal-regulated kinase (ERK) was reduced by doxorubicin, but the activity was restored by HGF. Levels of transforming growth factor-β1 and cyclooxygenase-2 did not differ between the groups. Our findings suggest the HGF gene delivery exerts therapeutic antiatrophic/degenerative and antifibrotic effects on myocardium in cases of established cardiac dysfunction caused by doxorubicin. These beneficial effects appear to be related to HGF-induced ERK activation and upregulation of c-Met, GATA-4, and sarcomeric proteins.

Staining of Capan-1 M9 cells without first antibodies as negative controls (A) and with antibody against β-catenin or Notch 1 (intra cellular domain: NICD) (B). Scale bar: 100 μm. Similar results were obtained in the staining of PANC-1, MIA PaCa-2 and Capan-1 cells (data not shown). The experiment was repeated three times and the representative results were indicated. Figure S2. The effects of signaling inhibitors on the frequency of CD133+ cells and the viability of pancreatic cancer cells. We treated Capan-1 M9 cells with the inhibitors at the indicated concentration for 3 days, then determined the frequency of CD133+ cells and their cell viability by flow cytometry and the MTT assay, respectively. The results are presented as percentages of control values in untreated cells, showing the mean and standard deviation (s.d.) of 4 replicates obtained in 1 representative experiment. Figure S3. The effects of GANT61 on the surface markers and the shape of Capan-1 M9 pancreatic cancer cells. (A) Flow cytometric analysis of CD133 and CD44 expression on Capan-1 M9 cells treated with or without GANT61. We treated the Capan-1 M9 cells for 3 days, then analyzed them. (B) Representative photographs of Capan-1 M9 cells untreated and treated with GANT61. GANT61 treatment induced a morphologic change of the Capan-1 M9 cells. This may correlate with the increased baseline level in the flow cytometric analysis of GANT61 treated cells shown in (A), which reflect the changes in the structure of the cell surface. Scale bar: 100 μm. Figure S4. The SMO-agonist SAG does not stimulate the sphere formation in Capam1M9 cells. We treated Capan-1 M9 cells with indicate4d concentration of SAG during sphere formation and determined the number of spheres formed per 96-well plate in triplicate. All data are mean and s.d. in 1 representative experiment out of 2. Table S1.Tumorigenesis of pancreatic cancer cell lines in NOD/SCID mice. Figure S5. The limiting dilution method is necessary to analyze the sphere-forming ability of PANC-1 cells. (A) PANC-1 cells form large aggregates in the multicellular sphere formation assay. We plated single-cell suspensions (103 cells in 0.5 ml) in 24 wells and cultured them. Representative photographs from day 2. (B) Representative photographs of PANC-1 spheres in the single-cell sphere formation assay. We plated single-cell suspensions (1.2 cells in 100 μl) in 96 wells and cultured them for 8 days. Scale bar: 100 μm. Figure S6. A heatmap of the DNA microarray demonstrates upregulation of GLI1 expression in spheres of Capan-1 M9 cells under stem cell culture condition. M9: Capan-1 M9 cells in two-dimensional culture with 10 % FCS, M9 Sphere: Capan-1 M9 spheres formed in a stem cell culture medium. Figure S7. (A) The hedgehog (Hh)/GLI inhibitor GANT61 (10 μM) in combination with the mTOR inhibitor rapamycin (10 nM) effectively reduced the sphere formation of Capan-1 M9 cells. The results are presented as in Fig. 3c. (B) The hedgehog (Hh)/GLI inhibitor GANT61 in combination with the mTOR inhibitor rapamycin impairs in vivo growth of xenografted pancreatic carcinoma in nude mice. Tumor growth of Capan-1 M9 xenografts which were treated with vehicle, 40 mg/kg of body weight, 1 mg/kg of body weight, or combination. Tumor volume was shown as the mean and SD from 5 mice (10 tumors) from each group. * P

Methyl-CpG-binding protein 2 (MeCP2) is an epigenetic regulator of gene expression that is essential for normal brain development. Mutations in MeCP2 lead to disrupted neuronal function and can cause Rett syndrome (RTT), a neurodevelopmental disorder. Previous studies reported cardiac dysfunction, including arrhythmias in both RTT patients and animal models of RTT. In addition, recent studies indicate that MeCP2 may be involved in cardiac development and dysfunction, but its role in the developing and adult heart remains unknown. In this study, we found that Mecp2-null ESCs could differentiate into cardiomyocytes, but the development and further differentiation of cardiovascular progenitors were significantly affected in MeCP2 deficiency. In addition, we revealed that loss of MeCP2 led to dysregulation of endogenous cardiac genes and myocardial structural alterations, although Mecp2-null mice did not exhibit obvious cardiac functional abnormalities. Furthermore, we detected methylation of the CpG islands in the Tbx5 locus and showed that MeCP2 could target these sequences. Taken together, these results suggest that MeCP2 is an important regulator of the gene-expression program responsible for maintaining normal cardiac development and cardiomyocyte structure.

The technical limitations of isolating target cells have restricted the utility of pluripotent embryonic stem (ES) cells. For example, early cardiac (i.e., precontractile) cells have not been isolated from ES cells. Here, we find that direct expression of reporter genes under cell-specific promoters—the currently available strategy for isolating cells lacking cell-specific surface markers—is ineffective for isolating progenitor cells. This was due to the weak activity of cell-specific promoters, particularly in ES cells at early stages. We show that adenoviral conditional targeting efficiently isolates viable ES cell-derived target cells without harmful effects. In this strategy, we employ the α-myosin heavy chain and Nkx2.5 promoter to visualize and purify efficiently differentiated and primitive cells of the cardiac lineage, respectively. While the former cells predominantly expressed sarcomeric proteins and maintained contractile function, the latter demonstrated neither of these features, but rather exhibited expression patterns characteristic of a mixture of primitive cells and cardiomyocytes. Interestingly, smooth muscle actin was predominantly expressed in the latter cells, and both functionally known and unknown genes were systematically identified, demonstrating the benefits of this system. Thus, our method facilitates molecular and cellular studies of development and ES cell-derived cell therapy.

Background: Effect of hepatocyte growth factor (HGF) has scarcely been determined on diabetic nephropathy. Methods: Adenovirus encoding human HGF gene or LacZ gene (as the control) was injected into the hindlimb muscles of the C57BL/KsJ-db/db (db/db) mice at the age of 12 weeks, a model of genetic diabetes. Diabetic nephropathy was then evaluated at the age of 24 weeks. Results: The urine volume and albumin excretion progressively decreased in the control, whereas they remained unchanged in the HGF-treated group during the 12-week follow-up. The HGF gene therapy did not affect glucose metabolism. However, it resulted in a better renal function as evaluated by creatinine clearance (Ccr) than the control; Ccr was progressively worsened in controls (0.14 ± 0.02 liters/day) whereas unchanged in the HGF gene-treated group (0.38 ± 0.09 liters/day, p < 0.05). Kidneys of the HGF gene-treated mice showed glomeruli with greater area and cell population, smaller glomerular sclerotic index, and less fibrosis in both glomeruli and renal tubules, where apoptotic rate of glomerular endothelial cells and that of tubular epithelial cells were significantly decreased. TGF-β1 expression was significantly decreased in kidneys of the HGF gene-treated group. Finally, the HGF treatment significantly improved the long-term survival of db/db mice. Conclusions: The HGF gene delivery thus appeared to slow down the aggravation of diabetic nephropathy in db/db mice by attenuating progression from the hyperfiltration phase into the sclerotic phase through antiapoptotic and antifibrotic actions. The present findings suggest that the HGF gene delivery can be a novel therapeutic approach against diabetic nephropathy.

遺伝子を治療道具として使う遺伝子治療は、臨床試験が世界中で進んでいます。実際の医療手技は、遺伝子導入ベクターを注射するだけというように一般医療と近く、癌など、一部は一般医薬化も近いといわれています。一方、近年話題の再生医学には二種類あり、まず元来の生体の再生能を利用し、再生誘導物質を投与して生体内で障害した臓器を再生・治療するという理想的な治療法があります。さらに近年開発が期待されているのは、多分化能と無限増殖能を持つES (胚性幹) 細胞などから、体外で目的の細胞を創って細胞移植するという、臓器移植に代わる治療法です。また骨髄細胞移植を用いた再生医学は、科学的メカニズムには疑問もありますが、臨床応用もなされています。このような先端医療開発や臨床応用も、西洋、東洋の医学と連携し、全人的な医療を目指している点で、実は鍼灸学と同じ目標を共有しています。

Insulin-like growth factor (IGF), hepatocyte growth factor (HGF), and heparin-binding epidermal growth factor-like growth factor (HB-EGF) are cardiogenic and cardiohypertrophic growth factors. Although the therapeutic effects of IGF and HGF have been well demonstrated in injured hearts, it is uncertain whether natural upregulation of HB-EGF after myocardial infarction (MI) plays a beneficial or pathological role in the process of remodeling. To answer this question, we conducted adenoviral HB-EGF gene transduction in in vitro and in vivo injured heart models, allowing us to highlight and explore the HB-EGF-induced phenotypes. Overexpressed HB-EGF had no cytoprotective or additive death-inducible effect on Fas-induced apoptosis or oxidative stress injury in primary cultured mouse cardiomyocytes, although it significantly induced hypertrophy of cardiomyocytes and proliferation of cardiac fibroblasts. Locally overexpressed HB-EGF in the MI border area in rabbit hearts did not improve cardiac function or exhibit an angiogenic effect, and instead exacerbated remodeling at the subacute and chronic stages post-MI. Namely, it elevated the levels of apoptosis, fibrosis, and the accumulation of myofibroblasts and macrophages in the MI area, in addition to inducing left ventricular hypertrophy. Thus, upregulated HB-EGF plays a pathophysiological role in injured hearts in contrast to the therapeutic roles of IGF and HGF. These results imply that regulation of HB-EGF may be a therapeutic target for treating cardiac hypertrophy and fibrosis.

Background— Fibrosis and progressive failure are prominent pathophysiological features of hearts after myocardial infarction (MI). We examined the effects of inhibiting transforming growth factor-β (TGF-β) signaling on post-MI cardiac fibrosis and ventricular remodeling and function. Methods and Results— MI was induced in mice by left coronary artery ligation. An adenovirus harboring soluble TGF-β type II receptor (Ad.CAG-sTβRII), a competitive inhibitor of TGF-β, was then injected into the hindlimb muscles on day 3 after MI (control, Ad.CAG-LacZ). Post-MI survival was significantly improved among sTβRII-treated mice (96% versus control at 71%), which also showed a significant attenuation of ventricular dilatation and improved function 4 weeks after MI. At the same time, histological analysis showed reduced fibrous tissue formation. Although MI size did not differ in the 2 groups, MI thickness was greater and circumference was smaller in the sTβRII-treated group; within the infarcted area, α-smooth muscle actin–positive cells were abundant, which might have contributed to infarct contraction. Apoptosis among myofibroblasts in granulation tissue during the subacute stage (10 days after MI) was less frequent in the sTβRII-treated group, and sTβRII directly inhibited Fas-induced apoptosis in cultured myofibroblasts. Finally, treatment of MI-bearing mice with sTβRII was ineffective if started during the chronic stage (4 weeks after MI). Conclusions— Postinfarction gene therapy aimed at suppressing TGF-β signaling mitigates cardiac remodeling by affecting cardiac fibrosis and infarct tissue dynamics (apoptosis inhibition and infarct contraction). This suggests that such therapy may represent a new approach to the treatment of post-MI heart failure, applicable during the subacute stage.

Background— We investigated whether the improvement of cardiac function and remodeling after myocardial infarction (MI) by granulocyte colony–stimulating factor (G-CSF) relates to acceleration of the healing process, in addition to myocardial regeneration. Methods and Results— In a 30-minute coronary occlusion and reperfusion rabbit model, saline (S) or 10 μg · kg −1 · d −1 of human recombinant G-CSF (G) was injected subcutaneously from 1 to 5 days after MI. Smaller left ventricular (LV) dimension, increased LV ejection fraction, and thicker infarct-LV wall were seen in G at 3 months after MI. At 2, 7, and 14 days and 3 months after MI, necrotic tissue areas were 14.2±1.5/13.4±1.1, 0.4±0.1/1.8±0.5*, 0/0, and 0/0 mm 2 · slice −1 · kg −1 , granulation areas 0/0, 4.0±0.7/8.5±1.0*, 3.9±0.8/5.7±0.7,* and 0/0 mm 2 · slice −1 · kg −1 , and scar areas 0/0, 0/0, 0/0, and 4.2±0.5/7.9±0.9* mm 2 · slice −1 · kg −1 in G and S, respectively (* P Conclusions— The acceleration of the healing process and myocardial regeneration may play an important role for the beneficial effect of post-MI G-CSF treatment.

Defects in chromosomes or mitotic spindles activate the spindle checkpoint, resulting in cell cycle arrest at prometaphase. The prolonged activation of spindle checkpoint generally leads to mitotic exit without segregation after a transient mitotic arrest and the consequent formation of tetraploid G(1) cells. These tetraploid cells are usually blocked to enter the subsequent S phase by the activation of p53/pRb pathway, which is referred to as the G(1) tetraploidy checkpoint. A human homologue of the Drosophila warts tumor suppressor, WARTS, is an evolutionarily conserved serine-threonine kinase and implicated in development of human tumors. We previously showed that WARTS plays a crucial role in controlling mitotic progression by forming a regulatory complex with zyxin, a regulator of actin filament assembly, on mitotic apparatus. However, when WARTS is activated during cell cycle and how the loss of WARTS function leads to tumorigenesis have not been elucidated. Here we show that WARTS is activated during mitosis in mammalian cells, and that overexpression of a kinase-inactive WARTS in Rat1 fibroblasts significantly induced mitotic delay. This delay resulted from prolonged activation of the spindle assembly checkpoint and was frequently followed by mitotic slippage and the development of tetraploidy. The resulting tetraploid cells then abrogated the G(1) tetraploidy checkpoint and entered S phase to achieve a DNA content of 8N. This impairment of G(1) tetraploidy checkpoint was caused as a consequence of failure to induce p53 expression by expressing a kinase-inactive WARTS. WARTS thus plays a critical role in maintenance of ploidy through its actions in both mitotic progression and the G(1) tetraploidy checkpoint.

Background Despite the pluripotency of embryonic stem (ES) cells, the specific control of their cardiomyogenic differentiation remains difficult. The aim of the present study was to investigate whether growth factors may efficiently enhance the in vitro cardiac differentiation of ES cells. Methods and Results Recombinant growth factors at various concentrations or their inhibitors were added according to various schedules during the cardiomyogenic differentiation of ES cells. Cardiomyogenic differentiation was assessed by mRNA and protein expressions of several cardiomyocyte-specific genes. Basic fibroblast growth factor-2 (FGF-2) and/or bone morphogenetic protein-2 (BMP-2) efficiently enhanced the cardiomyogenic differentiation, but only when they were added at the optimal concentration (1.0 ng/ml in FGF-2 and 0.2 ng/ml in BMP-2; relatively lower than expected in both cases) for the first 3 days. Inhibition of FGF-2 and/or BMP-2 drastically suppressed the cardiomyogenic differentiation. Conclusion FGF-2 and BMP-2 play a crucial role in early cardiomyogenesis. The achievement of efficient cardiac differentiation using both growth factors may facilitate ES cell-derived cell therapy for heart diseases as well as contribute to developmental studies of the heart. (Circ J 2004; 68: 691 - 702)

Human pluripotent stem cells (hPSCs) are promising sources for cell transplantation therapy. However, incomplete abolition of tumorigenicity, including teratomas and cancers, causes potential safety concerns in their clinical trials. Importantly, most previous approaches focused on “INDIRECT” inhibition of tumorigenicity by reducing the reprogramming-associated oncogenic potential of hiPSCs. Because they cannot completely eliminate tumorigenic potentials due to the intrinsic characteristics of hPSCs, innovative safety approaches should be developed. In this regard, we first developed “adenoviral conditional targeting”, which securely isolated target cells (Mol Ther. 14: 673-683. 2006), can increase the efficacy and safety by decreasing tumorigenicity. Second, we have recently developed a novel “oncolytic virus” strategy that specifically and efficiently eliminates undifferentiated cells, thereby inhibiting in vivo teratoma formation after hPSC transplantation (Mol Ther Methods Clin Dev. 2, 15026, 2015).Here we present the third antitumorigenic strategy by a novel methodology that can efficiently generate diverse “Tumorigenic Cell-targeting Lentiviral Vectors (TC-LVs). Tumorigenic cells in the transduced hPSCs can be specifically identified and efficiently killed by fluorescent genes and suicide genes, respectively, under the candidate promoters, which should be specifically and strongly activated in hPCSs in the undifferentiated and/or the transformed status, but not in the differentiated one.This system consists of two plasmids. One is the “LV-acceptor plasmid” (pLVA) that has a recombination cassette, upstream to the unit consisting of one of two fluorescence genes, 2A sequence and one of candidate suicide genes. The other is the “promoter-subcloning plasmid” (pPS) that has multicloning sites flanked by recombination sequences. We tested the feasibility and the utility of this construction system using the five candidate promoters. First, the promoters cloned into the pPS were surely transferred to pLVA having one of three candidate suicide genes and one of two fluorescent genes by using recombinase, resulting in the feasible and rapid generation of the different types of TC-LVs. To test the efficacy of this system, human and mouse PSCs were transduced with TC-LVs composing Venus (EGFP) and Herpes Simplex Virus Thymidine Kinase (HSV-tk) genes driven by either of the ubiquitously active CA or the cancer-specific survivin promoter, and the visualized PSCs were subsequently purified by a cell sorter. All of the PSCs in the undifferentiated status were almost perfectly killed by an addition of ganciclovir (GCV) in the GCV dose-dependent and the promoter activity-dependent manners, whereas they were viable in the differentiated status. The results importantly suggest the necessity of the best combination of the promoter (activity and specificity properties) and the suicide and the fluorescent genes.In conclusion, we have developed the novel method for a rapid generation of TC-LVs that can systematically identify the best promoter and suicide gene to surely eliminate tumorigenic cells, without harmful effect to the targeting differentiated cell. This methodology may facilitate the safe clinical application of PSCs-based cell therapy.View Large Image | Download PowerPoint Slide

The most serious problem in current gene therapy is discrepancies between experimental data and actual clinical outcomes, which may be due to insufficient analyses and/or inappropriate animal models. We have explored suicide gene therapy by using various clinically relevant animal models and doubt the clinical use of maximal suicide gene expression, which has been generally recommended. To explore this subject further, we studied what expression level of suicide gene and what promoter led to the maximal clinical benefit in the case of hepatic metastatic cancer in mice. Therapeutic and adverse side effects of 4 adenoviral vectors that express herpes simplex virus thymidine kinase (HSV-tk) under different promoters were scrupulously investigated in 2 mouse models of hepatic metastasis of gastric cancer that possess clinical characteristics. Surprisingly, increases in HSV-tk expression beyond a certain point, achieved by the Rous sarcoma virus long terminal repeat promoter, not only enhanced the adverse side effects of lethal hepatotoxicity and ganciclovir-independent cytotoxicity but also failed to further increase therapeutic potential. Moreover, the carcinoembryonic antigen (CEA) tumor-specific promoter, the therapeutic potential of which had been underestimated, was much more useful—even in the case of low CEA-producing cancer—than had been previously reported. In conclusion, the optimal therapeutic expression level of a suicide gene is a novel concept and a crucial factor for successful cancer gene therapy. The present results, which contradict those of previous studies, alert researchers about possible problems with ongoing and future clinical trials that lack this concept. (H EPATOLOGY 2003;37:155-163.)

The proto-oncogene c-myc is a multifunctional gene that regulates cell division, cell growth, and apoptosis. Here we report a new function of c-myc: induction of autophagy. Autophagy is a bulk degradation system for intracellular proteins. Autophagy proceeds with characteristic morphologies, which begins with the formation of a double-membrane structure called the autophagosome surrounding a portion of the cytoplasm, after which its outer membrane then fuses with the lysosomal membrane to become an autolysosome. Autophagosomes and autolysosomes are generally called autophagic vacuoles. When c-Myc protein was overexpressed in rat 3Y1 fibroblasts or when the chimeric protein c-MycER was activated by estrogen, the number of autophagic vacuoles in cells increased significantly. The formation of autophagic vacuoles induced by c-Myc was completely blocked by a specific inhibitor of autophagosome formation, 3-methyladenine. A c-Myc mutant lacking Myc Box II induced neither apoptosis nor oncogenic transformation, but still stimulated autophagy. An inhibitor of caspases suppressed apoptosis but not autophagy. These results suggest that the autophagy caused by c-myc is not due to the apoptosis or tumorigenesis induced by c-myc. Taken together, our results suggest that the induction of autophagy is a novel function of c-myc.

The signal transducer and activator of transcription (STAT) family proteins are transcription factors critical in mediating cytokine signaling. Among them, STAT3 is often constitutively phosphorylated and activated in human cancers and in transformed cell lines and is implicated in tumorigenesis. However, cause of the persistent activation of STAT3 in human tumor cells is largely unknown. The hepatitis C virus (HCV) is a major etiological agent of non-A and non-B hepatitis, and chronic infection by HCV is associated with development of liver cirrhosis and hepatocellular carcinoma. HCV core protein is proposed to be responsible for the virus-induced transformation. We now report that HCV core protein directly interacts with and activates STAT3 through phosphorylation of the critical tyrosine residue. Activation of STAT3 by the HCV core in NIH-3T3 cells resulted in rapid proliferation and up-regulation of Bcl-XL and cyclin-D1. Additional expression of STAT3 in HCV core-expressing cells resulted in anchorage-independent growth and tumorigenesis. We propose that the HCV core protein cooperates with STAT3, which leads to cellular transformation.

Background. Although adenovirus-mediated herpes simplex virus thymidine kinase (HSVtk) gene therapy is a potential candidate for a novel effective therapy for lung cancer, previous studies have been performed only in a subcutaneous tumor model employing nude mice. We studied therapeutic potentials in correlation with accurate adenoviral gene transduction efficiency in a more clinically relevant orthotopic lung cancer model employing imunocompetent mice. Methods. To analyze the cytotoxicity of adenoviral HSVtk gene transduction and ganciclovir, a cell proliferation assay was performed in vitro. A survival study was carried out in immunocompetent mice with orthotopic lung cancer, which was generated by intrapulmonary inoculation with syngeneic murine lung cancer cells that had been infected beforehand with each adenoviral vector at the predetermined gene transduction efficiencies. Results. Tumor cells were efficiently killed by infection with adenovirus carrying the HSVtk gene with the addition of ganciclovir in vitro. In the in vivo experiment all control mice died of rapid growth of the primary lung cancer and of metastases to mediastinal lymph nodes within 26 days after tumor inoculation. In contrast 50% and 100% of mice survived more than 40 days after inoculation with adenovirally HSVtk-transfected tumor cells that moderately and highly expressed HSVtk, respectively, when followed by ganciclovir administration. Gene transduction efficiencies were 67%. Conclusions. Adenovirus-mediated HSVtk gene therapy may be therapeutic for lung cancer when gene transduction efficiencies and sufficient expression levels of HSVtk can be achieved. Moreover, the present findings underscore the importance of the mouse orthotopic lung cancer model for studies of gene therapy.

Retrovirus-mediated gene delivery into hepatocytes in vivo provides long-term gene expression, which is of great importance for treating most genetic and metabolic disorders. However, clinical application has not been realized because of the requirement for prior 70% partial hepatectomy or chemical (toxic) liver injury to initiate hepatocyte replication at the time of retroviral gene transduction. In this paper, we describe a novel gene delivery system that uses recombinant hepatocyte growth factor (rHGF) prior to retrovirus-mediated in vivo gene transfer in the liver without partial hepatectomy or liver injury. A single retroviral infusion through the portal vein following five systemic injections (via the tail vein) of 100 microg/kg rHGF resulted in a 10.4% 5-bromo-2'-deoxyuridine (BrdU) labeling index (BLI) and 0.14% retroviral gene transduction efficiency (RGTE) in hepatocytes, which were 6.3- and 12.9-fold higher than those of controls, respectively. Modest additional increases in BLI and RGTE (13.4% and 0.22%, respectively) were seen after five systemic injections of 500 microg/kg rHGF. The correlation between BLI and RGTE was statistically confirmed regardless of treatment. When rats received multiple retroviral infusions through a cannulated portal vein following five portal injections of 100 microg/kg rHGF, RGTE was dramatically increased (1.3%) and in some areas of the liver exceeded more than 10%. There was no evidence of liver injury in any animal. This approach has great potential for clinical application in terms of avoiding invasive procedures or liver injury.

Excessive activity of the Fas system in the liver is an essential event and contributor to fulminant hepatic failure, whose prognosis is extremely poor with high mortality due to lack of effective therapy. Administration of agonistic anti-Fas antibody to mice rapidly led to massive liver apoptosis and fulminant hepatic failure. In contrast, administration of human recombinant hepatocyte growth factor (HGF) abrogated Fas-induced massive liver apoptosis and the lethal hepatic failure. Addition of anti-Fas antibody to hepatocytes in primary culture induced cell death, but Fas-mediated cell death was potently suppressed by HGF. HGF strongly induced Bcl-xL expression and subsequently blocked Fas-mediated signaling pathway upstream of CPP32 in the liver. These results implicate a potential therapeutic usage of HGF for treatment of fulminant hepatic failure.

In order to examine whether saliva and breast-milk are mediators of the vertical transmission of hepatitis C virus (HCV) from an HCV carrier mother, serum, saliva, and breast-milk samples from 11 HCV carrier mothers were collected at the time of delivery, and at approximately 1- to 3-months intervals for as long as 30 months postpartum. Serum was also sampled from their children. All samples were analysed for the presence of HCV RNA, using the nested polymerase chain reaction method. No HCV RNA was detected in any breast-milk samples. In saliva, HCV RNA was detected in four of the 11 mothers (36%). These four mothers also had liver function abnormalities. Hepatitis C virus RNA was not detected in any serum samples of the children, and all children had normal liver function. The children were monitored for periods from 2 to 44 months. During this period, there was no evidence of virus transmission. Breast-milk is not likely to be a source of mother-to-child transmission of HCV. Maternal saliva may harbour HCV, but it may not result in infant infection.

Interleukin-2 (IL-2) gene therapy alone and in combination with the herpes thymidine kinase gene (tk) was used to evaluate immunological responses and antitumor effects in head and neck cancer. Established floor of mouth squamous cell carcinomas in C3H/HeJ mice were directly injected with recombinant adenoviral vectors carrying both therapeutic and control genes. One week after adenoviral gene transfer, only the animals treated with combination IL-2+tk or tk alone demonstrated significant tumor regression. Residual tumors were harvested for microscopic evaluation and immunohistochemistry staining, which revealed a predominance of CD8+ lymphocytes in the tumor beds of the animals treated with IL-2. To evaluate the systemic immune effects of IL-2, animals treated with single or combination gene therapy received a second site challenge with parental tumor cells or a heterologous but syngeneic sarcoma cell line. Mice treated with combination IL-2 and tk demonstrated a protective systemic immunity specific to the parental tumor cell line, whereas no systemic immune response was evident in mice receiving IL-2 alone. In a separate experiment, a range of concentrations of the adenovirus IL-2 vector were used to treat established tumors. Even with the maximal single-dose adenovirus concentration, IL-2 alone was ineffective as a single therapy. These results support the use of adenovirus-mediated gene transfer of IL-2 as an effective immunotherapy when used adjuvantly with the tk “suicide gene”.

To assess the efficacy of an in vivo adenoviral-mediated cytotoxic gene therapy, human melanomas were established in nude mice and transduced with herpes simplex virus-thymidine kinase (tk) followed by treatment with ganciclovir (GCV). In initial experiments, adenovirus (adv) containing the beta-galactosidase reporter gene was employed to determine melanoma cell infectivity in vitro. In comparison to murine melanoma cell lines B16 and K1735-M2, human A375-SM cells exhibited up to a 10-fold greater susceptibility to adenoviral transduction, similar to the degree of infectivity found for human epidermal HaCaT cells. In addition, human A375-SM melanoma cells exhibited a greater sensitivity in vitro to the cytotoxic effects of transduction with tk-adv and treatment with GCV, which was mediated by a strong bystander effect. In vivo, intratumoral injection of relatively large human melanomas (160 mm3) with 1.2 X 109 pfu of tk-adv, followed by intraperitoneal GCV treatment (60 mg/kg twice daily) over 4 days, typically resulted in a 50% reduction in melanoma growth rate compared to mock or untreated controls. Moreover, histometrical analysis employing a rigorous computerized imaging system revealed that the residual viable tumor area in the tk-adv/GCV-treated group was only one-fifth that of solvent controls. These data show that adv is a highly efficient in vivo gene delivery system to treat experimental human melanomas. In comparison to a previous murine melanoma study, human melanomas appeared to exhibit a greater sensitivity to this cytotoxic treatment in vivo, which may hold significant promise for development of effective gene therapy modalities to treat melanoma in humans.

Objective : Two Japanese brothers with neonatal cholestasis associated with pigment granules in the hepatocytes and hepatosteatosis were evaluated for the possible role of hepatosteatosis in the Dubin-Johnson syndrome. Methodology and results The morphology of pigment accumulation and the laboratory data in these cases were examined. The elevation of urinary coproporphrin isomer I to more than 90% and the presence cholestasis resembled that in the Dubin-Johnson syndrome, but the hypertriglyceridaemia (

We developed a method to efficiently construct diverse “conditionally replicating adenoviruses regulated with multiple cancer-specific factors” (m-CRAs) for an ideal gene-viro-therapy (Gene Ther 2005), after we had developed the immunological gene therapy, including granulocyte macrophage colony-stimulating factor (GM-CSF) (PNAS 1995, 1996, Cancer Res 1996). We then identified by systematic m-CRA analyses that survivin-responsive m-CRA (Surv.m-CRA), in which E1A is regulated by survivin promoter, could achieve stronger and more cancer-selective potentials than competing m-CRAs (Cancer Res 2005). The new Surv.m-CRA, of which an altered E1B promoter is regulated with another cancer-specific promoter (CS-Pr), further increased cancer specificity without reduced anticancer effects (Cancer Gene Ther 2011). Moreover, the unique feature of the increased effectiveness against cancer stem cells suggests that Surv.m-CRA is promising anticancer agent (J Trans Med 2014). In addition, we have developed a novel m-CRA strategy that specifically eliminates undifferentiated cells in pluripotent stem cell-based regenerative medicine (Mol Ther Methods Clin Dev 2015). Taken altogether, we are about to start its clinical trial in Japan. As the first-in-class oncolytic virus expressing GM-CSF was recently approved, m-CRAs expressing immunostimulatory genes should be promising. In general, the development of oncolytic adenoviruses with cytokines has been hampered by two technical limitations in the vector construction and the viral replication-permissive animals. Here we demonstrate a novel system to efficiently generate diverse types of m-CRAs expressing candidate immunostimulatory genes under candidate promoters, and systematically analyze their potentials in syngenic hamster models. We tested the feasibility of this methodology, and succeeded in the rapid generation of the new Surv.m-CRAs comprising 18 different therapeutic units, including a mouse or human cytokine gene downstream to a ubiquitously active promoter (UA-Pr) or CS-Pr. To test the utility of our experimental system, we first analyzed in vivo antitumor efficiencies and toxicities of Surv.m-CRA expressing GM-CSF under a strong UA-Pr in xenograft syngeneic tumor of syrian hamster. An intratumoral injection of the control Surv.m-CRA without GM-CSF inhibited a tumor growth and extended a survival to some degrees. Whereas Surv.m-CRAs expressing mouse GM-CSF more drastically reduced tumor growth, some of these animals died of excessive GM-CSF expressions (showing the remarkable splenomegaly) within 3 days. The results importantly suggest the necessity of systematical analyses to identify the best combination of cytokine genes and promoters to achieve the optimal cytokine levels (Int J Oncol 2004), and we are now analyzing 18 different Surv.m-CRAs, including those expressing GM-CSF at a moderate level and/or in the cancer-specific manner. In conclusion, we have developed a novel system to efficiently generate the candidate m-CRAs expressing diverse immunostimulatory genes under several promoters and to systematically analyze them in syngenic hamster models.View Large Image | Download PowerPoint Slide

Rett syndrome (RTT) is a neurodevelopmetal disorder associated with mutations in the methyl-CpG–binding protein 2 (MeCP2) gene. MeCP2-deficient mice recapitulate the neurological degeneration observed in RTT patients. Recent studies indicated a role of not only neurons but also glial cells in neuronal dysfunction in RTT. We cultured astrocytes from MeCP2-null mouse brain and examined astroglial gene expression, growth rate, cytotoxic effects, and glutamate (Glu) clearance. Semi-quantitative RT-PCR analysis revealed that expression of astroglial marker genes, including GFAP and S100β, was significantly higher in MeCP2-null astrocytes than in control astrocytes. Loss of MeCP2 did not affect astroglial cell morphology, growth, or cytotoxic effects, but did alter Glu clearance in astrocytes. When high extracellular Glu was added to the astrocyte cultures and incubated, a time-dependent decrease of extracellular Glu concentration occurred due to Glu clearance by astrocytes. Although the shapes of the profiles of Glu concentration versus time for each strain of astrocytes were grossly similar, Glu concentration in the medium of MeCP2-null astrocytes were lower than those of control astrocytes at 12 and 18 h. In addition, MeCP2 deficiency impaired downregulation of excitatory amino acid transporter 1 and 2 (EAAT1/2) transcripts, but not induction of glutamine synthetase (GS) transcripts, upon high Glu exposure. In contrast, GS protein was significantly higher in MeCP2-null astrocytes than in control astrocytes. These findings suggest that MeCP2 affects astroglial genes expression in cultured astrocytes, and that abnormal Glu clearance in MeCP2-deficient astrocytes may influence the onset and progression of RTT.

Although previous studies modified two components of conditionally replicating adenoviruses (CRAs), which selectively replicate in and kill cancer cells, the most accurate ways to achieve increased cancer specificity (that is, safety) without reducing the anticancer (that is, therapeutic) effects are unknown. Here, we generated two types of survivin-responsive m-CRAs (Surv.m-CRAs), Surv.m-CRA-CMVp and Surv.m-CRA-OCp, which use two and three different mechanisms to target cancer, that is, early region 1A (E1A) regulated by the survivin promoter and mutated E1BΔ55K regulated by the ubiquitously active cytomegalovirus promoter and cancer/tissue-specific osteocalcin promoter, respectively, and carefully examined their safety and anticancer effects. Endogenous osteocalcin mRNA was expressed and further enhanced by vitamin D(3) in all osteosarcoma and prostate cancer cell lines and human osteoblasts, but not in human fibroblasts. The osteocalcin promoter activity was weak even with vitamin D(3) treatment in these osteocalcin-expressing cancers, leading to low E1BΔ55K expression after Surv.m-CRA-OCp infection. Nevertheless, Surv.m-CRA-OCp had significantly increased cancer specificity without reduced anticancer effects in both in vitro and in vivo experiments. The unexpected but favorable fact that strong activity of an altered E1B promoter is unnecessary indicates that the majority of cancer/tissue-specific promoters may be used to generate ideal m-CRAs and will advance the development of m-CRA-based cancer therapies.

The aim of this study is to investigate the role of hepatic stellate cells (HSCs) and the effect of vitamin A administration on liver damage induced by bile duct ligation (BDL) and administration of CCl(4).Two types of animal model were used; one was BDL as a model of biliary atresia, the other was CCl(4)-induced hepatic fibrosis. Pathological changes of the liver with or without administration of vitamin A were compared by light and electron microscopy with focusing on HSCs in each experimental group. Immunohistochemical examination was performed with anti-keratinocyte growth factor (KGF), anti-alpha-smooth muscle actin (α-SMA), and anti-glial fibrillary acidic protein (GFAP) antibodies, as markers of fibrosis.On light microscopic findings, periportal inflammation with bile ductular proliferation was obvious in BDL group and pericentral necrosis with fatty degeneration was observed in CCl(4) group, both of which were ameliorated by subcutaneous injection of vitamin A. Electron microscopy showed lipid droplets were almost depleted in the HSCs treated with BDL or CCl(4), which improved with vitamin A administration. Immunohistochemistry demonstrated that enhanced expression of all three fibrotic markers in the BDL group was diminished by vitamin A administration.Although most of our data are qualitative observation, vitamin A may ameliorate hepatic fibrosis in the BDL model by restoring vitamin A in the HSCs.

The incidence of diabetes is increasing worldwide, yet current treatments are not always effective for all patient or disease types.Here, we summarize the biologic and clinical roles of leptin in diabetes, and discuss candidate viral vectors that may be employed in the clinical use of central leptin gene therapy for diabetes.We discuss how studies on leptin, a regulator of the insulin-glucose axis, have significantly advanced our understanding of the roles of energy homeostasis and insulin resistance in the pathogeneses of metabolic syndrome and diabetes. Recent studies have demonstrated the long-term therapeutic effects of central leptin gene therapy in obesity and diabetes via decreased insulin resistance and increased glucose metabolism. Many of these studies have employed viral vectors, which afford high in vivo gene transduction efficiencies compared with non-viral vectors.Adeno-associated viral vectors are particularly well suited for central leptin gene therapy owing to their low toxicity and ability to drive transgene expression for extended periods.