Adenovirus as a Vector and Oncolytic Virus.

Adenoviral vectors, both oncolytic viruses and gene delivery vectors, are among the earliest approved and commercialised vectors for gene therapy. Adenoviruses have high cytotoxicity and immunogenicity. Therefore, lentiviruses or adeno-associated viruses as viral vectors and herpes simplex virus as an oncolytic virus have recently drawn attention. Thus, adenoviral vectors are often considered relatively obsolete. However, their high cargo limit and transduction efficiency are significant advantages over newer viral vectors. This review provides an overview of the new-generation adenoviral vectors. In addition, we describe the modification of the fiber knob region that enhances affinity of adenoviral vectors for cancer cells and the utilisation of cancer-cell-specific promoters to suppress expression of unwanted transgenes in non-malignant tissues.

Nicotinamide Mononucleotide Is Safely Metabolized and Significantly Reduces Blood Triglyceride Levels in Healthy Individuals.

An increase in nicotinamide adenine dinucleotide (NAD+) levels alleviates age-related disease progression and promotes healthy life expectancy. Several studies have demonstrated that NAD+ levels can be efficiently replenished via nicotinamide mononucleotide (NMN) intake; additionally, the safety of its oral ingestion has been confirmed in recent clinical trials. However, the efficacy and safety of intravenous NMN administration in humans remain unclear. Therefore, we verified its safety in 10 healthy volunteers. Intravenous administration of NMN did not affect electrocardiograms, pulse, and blood pressure, nor did it affect metabolic markers in the liver, heart, pancreas, and kidneys. These results indicate that intravenous NMN administration is safe and beneficial in humans. Furthermore, NMN administration significantly increased blood NAD+ levels without damaging blood cells and significantly reduced blood triglyceride (TG) levels. These findings imply that intravenous administration of NMN may lead to the prevention and treatment of diseases associated with increased TG levels, such as fatty liver and diabetes.

Effects of inhalable gene transfection as a novel gene therapy for non-small cell lung cancer and malignant pleural mesothelioma.

Gene therapy using vectors has attracted attention in recent years for the treatment of cancers caused by gene mutations. Besides, new treatments are imperative for lung cancer, including non-small cell lung cancer (NSCLC) and malignant pleural mesothelioma (MPM), due to its high mortality. We developed a minimally invasive and orally inhalable tumor suppressor gene drug (SFD-p16 and SFD-p53) with non-viral vectors for lung cancer treatment by combining tumor suppressor genes with an inhalant powder that can deliver active ingredients directly to the lung. We used NSCLC (A549 and H1299) and MPM (H2052) cell lines in an air-liquid interface culture. Transfection of A549 and H2052 cells with SFD-p16 significantly increased p16 mRNA expression levels and decreased cell proliferation in both cell lines. Similar results were obtained with transfection of H1299 with the inhalable gene drug SFD-p53. In an in vivo experiment, a mouse model of lung cancer with orthotopically transplanted luciferase-expressing A549 cells was subjected to intratracheal insufflation of SFD-p16. Consequently, SFD-p16 effectively and directly affected lung cancer. This study suggests that inhalable gene drugs are effective treatments for NSCLC and MPM. We expect inhalable gene drugs to present a novel gene therapy agent for lung cancer that patients can self-administer.

Triple-negative expression (ALDH1A1-/CD133-/mutant p53-) cases in lung adenocarcinoma had a good prognosis.

Cancer stem cells (CSCs) are major contributors to the malignant transformation of cells because of their capacity for self-renewal. Aldehyde dehydrogenase1A1 (ALDH1A1) and CD133 are promising candidate of CSC markers in non-small cell lung cancer (NSCLC). Furthermore, TP53 is frequently mutated in lung cancer, and the loss of its function is associated with malignant characteristics. However, the relationship between CSCs and mutant p53 in lung adenocarcinoma is not well-established. We examined the expression of ALDH1A1, CD133, and mutant p53 in lung adenocarcinoma patients and conducted a clinicopathological study. Triple-negative cases without ALDH1A1, CD133, and mutant p53 expression in lung adenocarcinoma were shown to have a much better prognosis than others. Our present results suggest that detection of CSC markers and mutant p53 by immunohistochemical staining may be effective in therapeutic strategies for lung adenocarcinoma.

Cancer Cell-specific Transfection of hCas9 Gene Using Ad5F35 Vector.

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.

Association Between CD133 Expression and Prognosis in Human Lung Adenocarcinoma.

BACKGROUND/AIM: CD133 is a promising candidate marker for cancer stem cells. However, clinical studies on CD133 expression in human lung adenocarcinoma have not yet been conducted. We hypothesized that CD133 expression in lung adenocarcinoma is a poor prognostic factor. PATIENTS AND METHODS: CD133 expression in lung adenocarcinoma was examined clinicopathologically. Then, clinicopathological parameters and patient prognosis were investigated. Moreover, CD133 expression was examined via immunohistochemical staining, and the relationship between CD133 expression and clinicopathological parameters was explored. RESULTS: Approximately 48.0% (49/102) of patients had CD133-positive cells. Based on a subgroup analysis, the CD133-positive group with pStage I+II disease had a significantly worse disease-free interval than the CD133-negative group (p<0.05). CONCLUSION: CD133 expression may be a poor prognostic factor in lung adenocarcinoma.

Identification of HUHS190, a human naftopidil metabolite, as a novel anti-bladder cancer drug.

We carried out structure-activity relationship study on anti-cancer effects of naftopidil (1) and its metabolites, resulted in identification of 1-(4-hydroxy-2-methoxyphenyl)piperazin-1-yl)-3-(naphthalen-1-yloxy) propan-2-ol (2, HUHS190), a major human metabolite of 1, which exhibited the most selective toxicities between against normal and cancer cells (Table 1). 2 was more hydrophilic compared to 1, was enough to be prepared in high concentration solution of more than 100 µM in saline for an intravesical instillation drug. Moreover, serum concentration of 2 was comparable to that of 1, an oral preparation drug, after oral administration at 32 mg/kg (Fig. 3). Both of 1 and 2 showed broad-spectrum anti-cancer activities in vitro, for example, 1 and 2 showed inhibitory activity IC50 = 21.1 µM and 17.2 µM for DU145, human prostate cancer cells, respectively, and IC50 = 18.5 µM and 10.5 µM for T24 cells, human bladder cancer cells. In this study, we estimated anticancer effects of 2 in a bladder cancer model after intravesical administration similar to clinical cases. A single intravesical administration of 2 exhibited the most potent inhibitory activities among the clinical drugs for bladder cancers, BCG and Pirarubicin, without obvious side effects and toxicity (Fig. 4). Thus, HUHS190 (2) can be effective for patients after post-TURBT therapy of bladder cancer without side effects, unlike the currently available clinical drugs.

Lentiviral Vector-mediated Gene Transfer in Human Bladder Cancer Cell Lines.

BACKGROUND/AIM: Currently, treatment of non-muscle invasive bladder cancer causes significant deterioration in a patient's quality of life (QOL). Therefore, development of novel therapeutic options without the deterioration of QOL is very important. In this study, we assessed the anti-tumor effect of lentivirus-mediated gene transfection of tumor-suppressor genes in human bladder cancer cells. MATERIALS AND METHODS: Lentiviral vectors that contained the tumor suppressor genes, p53, p16, and PTEN, were transfected into human bladder cancer cell lines, 5637, T24, 253J, and UMUC3, and the normal human uroepithelial cell line, SV-HUC-1. RESULTS: Significant growth inhibition was observed in bladder cancer cells on transfection with the p16 and PTEN vectors. However, the effect of the p53 vector was limited. In normal cells, the lentiviral vectors did not exhibit a significant growth inhibitory effect. CONCLUSION: Lentiviral vector-mediated gene transfection is useful for the application of gene therapy in bladder cancers.

Autophagy Induced by Naftopidil Inhibits Apoptosis of Human Gastric Cancer Cells.

AIM: Naftopidil is used to treat benign prostate hyperplasia. Moreover, previous studies have shown that naftopidil reduced viability of many types of cancer cells. Therefore, we investigated the antitumor mechanism of naftopidil in this study. MATERIALS AND METHODS: We used the HGC27 human gastric cancer cell line. It was treated with naftopidil, pan-caspase inhibitor, and chloroquine diphosphate (CQ). Cell viability and cell death were investigated by the assay and annexin V/ propidium iodide assay. Phosphorylation of protein kinase B (AKT) (Ser473) was measured by western blotting. Alteration of light chain 3B (LC3B) was investigated by western blotting and immunofluorescence. RESULTS: Naftopidil reduced phospho-AKT (Ser473) and altered LC3B. Combination of naftopidil and CQ reduced cell viability and phospho-AKT (Ser 473). CONCLUSION: Naftopidil induces apoptosis and autophagy of HGC27 cells, however, autophagy is considered to inhibit apoptosis. We concluded naftopidil and CQ have a synergistic antitumor effect.

The Clinical Significance of Cancer Stem Cell Markers ALDH1A1 and CD133 in Lung Adenocarcinoma.

BACKGROUND/AIM: Aldehyde dehydrogenase-1A1 (ALDH1A1) and CD133 have been identified as markers of cancer stem cells (CSCs). We investigated the expression of these markers and their clinical significance in lung adenocarcinoma. MATERIALS AND METHODS: An immunohistochemical analysis of ALDH1A1 and CD133 expression of 92 lung adenocarcinomas was performed. The association between the expression of both markers and cancer-related death and recurrence was determined. RESULTS: Cancer-related death and tumor recurrence were observed in 15 and 17 cases, respectively. The expression of CD133, but not ALDHA1A, was significantly associated with poorer overall survival (p<0.0001) and shorter disease-free interval (DFI) (p<0.0001). Multivariate analysis revealed that double negativity was independently associated with increased survival (hazard ratio(HR)=16.1, p=0.0004) and a longer DFI (HR=9.5, p=0.0007). CONCLUSION: We propose that as a functional marker, ALDH1A1 positivity may influence the viability of CSCs. The findings suggest that it is important to evaluate the expression of both markers.

The phosphatidylethanolamine derivative diDCP-LA-PE mimics intracellular insulin signaling.

Insulin facilitates glucose uptake into cells by translocating the glucose transporter GLUT4 towards the cell surface through a pathway along an insulin receptor (IR)/IR substrate 1 (IRS-1)/phosphatidylinositol 3 kinase (PI3K)/3-phosphoinositide-dependent protein kinase-1 (PDK1)/Akt axis. The newly synthesized phosphatidylethanolamine derivative 1,2-O-bis-[8-{2-(2-pentyl-cyclopropylmethyl)-cyclopropyl}-octanoyl]-sn-glycero-3-phosphatidylethanolamine (diDCP-LA-PE) has the potential to inhibit protein tyrosine phosphatase 1B (PTP1B) and to directly activate PKCζ, an atypical isozyme, and PKCε, a novel isozyme. PTP1B inhibition enhanced insulin signaling cascades downstream IR/IRS-1 by preventing tyrosine dephosphorylation. PKCζ and PKCε directly activated Akt2 by phosphorylating at Thr309 and Ser474, respectively. diDCP-LA-PE increased cell surface localization of GLUT4 and stimulated glucose uptake into differentiated 3T3-L1 adipocytes, still with knocking-down IR or in the absence of insulin. Moreover, diDCP-LA-PE effectively reduced serum glucose levels in type 1 diabetes (DM) model mice. diDCP-LA-PE, thus, may enable type 1 DM therapy without insulin injection.

Piperazine-based Alpha-1 AR Blocker, Naftopidil, Selectively Suppresses Malignant Human Bladder Cells via Induction of Apoptosis.

A retrospective observational cohort study has shown that exposure to alpha-1 adrenergic receptor (AR) blocker reduces the risk of bladder cancer (BCa). We investigated the antitumor activity of alpha-1 blockers, that are administered long-term therapeutically, in BCa. The antitumor activity of alpha-1 blockers was evaluated in terms of cell viability, cell cycle, competition, and apoptotic signaling in BCa cells. Our cell viability studies showed that naftopidil was one of the strongest alpha-1 AR blockers, regarding its antitumor action in BCa cells, independent of the grade of malignancy, but with no similar action on normal human bladder cells. Oral administration of naftopidil reduced tumor volume in a xenograft model. Our own competitive analysis using an alpha-1 AR agonist and other alpha-1 AR blockers showed that naftopidil activated cell death signaling without inhibitory action on alpha-1 ARs. We conclude that naftopidil has potential as an antitumor drug against BCa in vitro and in vivo. This finding provides a rationale for developing naftopidil in grade-independent treatment of BCa.

Adenosine deaminase inhibitor EHNA exhibits a potent anticancer effect against malignant pleural mesothelioma.

BACKGROUND/AIMS: Malignant pleural mesothelioma (MPM) is an aggressive malignant tumor and an effective therapy has been little provided as yet. The present study investigated the possibility for the adenosine deaminase (ADA) inhibitor EHNA as a target of MPM treatment. METHODS: MTT assay, TUNEL staining, monitoring of intracellular adenosine concentrations, and Western blotting were carried out in cultured human MPM cell lines without and with knocking-down ADA. The in vivo effect of EHNA was assessed in mice inoculated with NCI-H2052 MPM cells. RESULTS: EHNA induced apoptosis of human MPM cell lines in a concentration (0.01-1 mM)- and treatment time (24-48 h)-dependent manner, but such effect was not obtained with another ADA inhibitor pentostatin. EHNA increased intracellular adenosine concentrations in a treatment time (3-9 h)-dependent manner. EHNA-induced apoptosis of MPM cells was mimicked by knocking-down ADA, and the effect was neutralized by the adenosine kinase inhibitor ABT-702. EHNA clearly suppressed tumor growth in mice inoculated with NCI-H2052 MPM cells. CONCLUSION: The results of the present study show that EHNA induces apoptosis of MPM cells by increasing intracellular adenosine concentrations, to convert to AMP, and effectively prevents MPM cell proliferation. This suggests that EHNA may be useful for treatment of the tragic neoplasm MPM.

Naftopidil is useful for the treatment of malignant pleural mesothelioma.

Naftopidil, an α1-adrenoceptor blocker, induced apoptosis of human malignant pleural mesothelioma NCI-H2052 cells. Naftopidil upregulated the expression of tumor necrosis factor-α (TNF-α) mRNA in these cells. Naftopidil, alternatively, increased FasL secretion from NCI-H2052 cells, without affecting the expression of FasL mRNA and protein, and activated caspase-3 and -8 in NCI-H2052 cells. Naftopidil drastically suppressed tumor growth in mice inoculated with these cells. The results of the present study indicate that naftopidil induces apoptosis of NCI-H2052 cells by upregulating the expression of TNF-α and stimulating the secretion of FasL, a ligand for the death receptor Fas, both to activate caspase-8 and the effector caspase-3, leading to the suppression of NCI-H2052 cell proliferation in vivo. This raises the possibility that naftopidil could be developed as an effective drug for the treatment of malignant pleural mesothelioma.

Newly synthesized anticancer drug HUHS1015 is effective on malignant pleural mesothelioma.

The newly synthesized naftopidil analogue HUHS1015 reduced cell viability in malignant pleural mesothelioma cell lines MSTO-211H, NCI-H28, NCI-H2052, and NCI-H2452, with the potential greater than that for the anticancer drugs paclitaxel or cisplatin at concentrations higher than 30 µM. HUHS1015 induced both necrosis and apoptosis of MSTO-211H and NCI-H2052 cells. HUHS1015 upregulated expression of mRNAs for Puma, Hrk, and Noxa in MSTO-211H and NCI-H2052 cells, suggesting HUHS1015-induced mitochondrial apoptosis. HUHS1015 clearly suppressed tumor growth in mice inoculated with NCI-H2052 cells. Taken together, the results of the present study indicate that HUHS1015 could be developed as an effective anticancer drug for treatment of malignant pleural mesothelioma.

Biosafety studies of carrier cells infected with a replication-competent adenovirus introduced by IAI.3B promoter.

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.

Crosstalk between PI3 kinase/PDK1/Akt/Rac1 and Ras/Raf/MEK/ERK pathways downstream PDGF receptor.

BACKGROUND/AIMS: Our earlier studies suggested crosstalk between IRS/PI3 kinase/PDK1/Akt/Rac1/ROCK and (Shc2/Grb2/SOS)/Ras/Raf/MEK/ERK pathways downstream PDGF-ßß receptor responsible for chemotaxis and proliferation of malignant mesothelioma cells. The present study was conducted to obtain evidence for this. METHODS: To assess activation of Akt, MEK, and ERK, Western blotting was carried out on MSTO-211H malignant mesothelioma cells using antibodies against phospho-Thr308-Akt, phopho-Ser473-Akt, Akt, phospho-MEK, MEK, phopho-ERK1/2, and ERK1/2. To knock-down Akt, PI3 kinase, PDK1, and Rac1, siRNAs silencing each-targeted gene were constructed and transfected into cells. To monitor Rac1 activity, FRET monitoring was carried out on living and fixed cells. RESULTS: ERK was activated under the basal conditions in MSTO-211H cells, and the activation was prevented by inhibitors for PI3 kinase, PDK1, Akt, and Rac1 or by knocking-down PI3 kinase, PDK1, Akt, and Rac1. Akt was also activated under the basal conditions, and the activation was suppressed by a MEK inhibitor and an ERK1/2 inhibitor. In the FRET analysis, Rac1 was activated under the basal conditions, and the activation was inhibited by a MEK inhibitor and an ERK1/2 inhibitor. CONCLUSION: The results of the present study show that ERK could be activated by PI3 kinase, PDK1, Akt, and Rac1 and that alternatively, Akt and Rac1 could be activated by MEK and ERK in MSTO-211H cells.

Naftopidil induces apoptosis in malignant mesothelioma cell lines independently of α1-adrenoceptor blocking.

BACKGROUND: Naftopidil, an α1-adrenoceptor blocker, has been clinically used for the treatment of benign prostate hyperplasia and hypertension. Emerging evidence has shown that naftopidil exhibits an antitumor effect on a variety of cancer types including prostate cancer. The aim of the present study was to investigate naftopidil-induced apoptosis in human malignant mesothelioma cells and to shed light on the underlying mechanism. MATERIALS AND METHODS: 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining, western blotting, and enzymatic assay of caspase-3, -8, and -9 activities were carried out on human malignant mesothelioma cell lines NCI-H28, NCI-H2052, NCI-H2452, and MSTO-211H cells. To knock-down α1D-adrenoceptor, siRNA to silence human α1D-adrenoceptor-targeted gene was constructed and transfected into cells. RESULTS: Naftopidil induced apoptosis in all the investigated malignant mesothelioma cells, and a similar effect was obtained with prazosin, another α1-adrenoceptor blocker. α1-Adrenoceptor is linked to Gq/11 protein involving activation of protein kinase C (PKC). Naftopidil-induced reduction in cell viability was inhibited by GF109203X, while prazosin-induced in cell viability was less affected. Knocking-down α1D-adrenoceptor promoted malignant mesothelioma cell proliferation. Both naftopidil and prazosin activated caspase-3 and -8 in all the investigated malignant mesothelioma cells. CONCLUSION: Naftopidil, as well as prazosin, has the potential to induce apoptosis in malignant mesothelioma cells by activating caspase-8 and the effector caspase-3, regardless of α1-adrenoceptor blocking.

Fiber-substituted conditionally replicating adenovirus Ad5F35 induces oncolysis of human bladder cancer cells in in vitro analysis.

OBJECTIVE: To assess the oncolytic effect of fiber-substituted conditionally replicating adenovirus type 5 (Ad5) F35 vector on human bladder cancer cell lines such as 253J, 5637, KK-47, T24, TCCSUP, and UMUC-3 cells. MATERIALS AND METHODS: Ad5F35 and Ad5 conditionally replicating adenovirus vectors containing the E1 gene controlled by the human midkine promoter (Ad5F35/MKp-E1 and Ad5/MKp-E1, respectively) were constructed. Reverse transcriptase-polymerase chain reaction and cell viability assay were performed in cells transfected with Ad5F35/MKp-E1 or Ad5/MKp-E1. RESULTS: Of the bladder cancer cells used, considerably lower expression of mRNA for Coxsackie and adenovirus receptor, an Ad5 receptor, was found with T24 and TCCSUP cells. However, the mRNA for CD46, an Ad35 receptor, was abundantly expressed in all the cell types. Ad5F35/MKp-E1 induced oncolysis in a plaque formation unit-dependent manner for all the bladder cancer cells used, with greater efficacy than Ad5/MKp-E1 for T24, TCCSUP, and 253J cells. CONCLUSION: The results of the present study have shown that Ad5F35/MKp-E1 is more useful for the gene therapy of bladder cancer than Ad5/MKp-E1 is for some cell lines.

A3 adenosine receptor mediates apoptosis in in vitro RCC4-VHL human renal cancer cells by up-regulating AMID expression.

PURPOSE: Accumulating studies have shown that extracellular adenosine induces apoptosis in various cancer cells via diverse signaling pathways. We sought to understand adenosine induced apoptosis in human renal cancer cells and the underlying pathway. MATERIALS AND METHODS: RCC4-VHL (European Collection of Animal Cell Cultures, Salisbury, United Kingdom), ACHN (Cell Resource Center for Biomedical Research, Institute of Development, Aging and Cancer, Tohuku University, Aoba-ku, Sendai, Japan) and 786-O (ATCC®) human renal cancer cells were cultured. MTT assay, TUNEL staining, reverse transcriptase-polymerase chain reaction and Western blot were done in cells untransfected and transfected with siRNA silencing the A(3) adenosine receptor targeted gene or the AMID targeted gene. RESULTS: Adenosine induced apoptosis in all cell types used in a concentration (1 to 10 mM) dependent manner. A similar effect was obtained with the A(3) adenosine receptor agonist 2-Cl-IB-MECA. Adenosine induced RCC4-VHL cell death was inhibited by the A(3) adenosine receptor inhibitor MRS1191 or by knocking down A(3) adenosine receptor or AMID. Adenosine up-regulated the expression of AMID mRNA and protein in RCC4-VHL cells, which was suppressed by A(3) adenosine receptor knockdown. Moreover, adenosine promoted AMID translocation from cytosol to nucleus. CONCLUSIONS: Adenosine induces RCC4-VHL cell apoptosis by up-regulating AMID expression and accumulating AMID in the nucleus via A(3) adenosine receptor.