Effect of Phosphoribosyltransferase Down-regulation on Malignant Glioma Cell Characteristics.

BACKGROUND/AIM: Nicotinamide phosphoribosyl-transferase (NAMPT) is a rate-limiting enzyme in the pathway synthesizing nicotinamide adenine dinucleotide (NAD (+)) from nicotinamide (NAM). Glioma tissues exhibit up-regulated NAMPT expression associated with a poor prognosis of patients. To determine if NAMPT can be a molecular therapeutic target, we investigated the effects of short hairpin RNA (shRNA)-mediated NAMPT down-regulation. MATERIALS AND METHODS: We designed shRNA to NAMPT and transfected to T98G cells. The characteristics of these cells were analyzed. RESULTS: The NAMPT shRNA-transfected cells exhibited delayed cell growth. However, there was no difference in the increase of sensitivity to temozolomide (TMZ) or X-ray irradiation between the NAMPT and scramble shRNA-transfected cells. The expression of NAMPT in the NAMPT shRNA-transfected cells increased with cell passage. Additionally, the shRNA-mediated transfection was associated with enhanced expression of quinolinic acid phosphoribo-syltransferase (QPRT). CONCLUSION: shRNA-mediated NAMPT down-regulation may not decrease the NADt to a sufficient level to increase TMZ/radiation sensitivity.

Evaluation of basophil activation caused by transgenic rice seeds expressing whole T cell epitopes of the major Japanese cedar pollen allergens.

BACKGROUND: Japanese cedar (JC) pollinosis is a serious type I allergic disease in Japan. Although subcutaneous immunotherapy and sublingual immunotherapy have been applied to treat JC pollinosis, high doses of allergens may cause IgE-mediated allergic reactions. The transgenic rice seeds that contain genetically modified Cry j 1 and Cry j 2, the two major allergens of JC pollen, have been developed as candidates for oral immunotherapy. Although the antigens in the transgenic rice seeds (Tg-rice seeds) were engineered such that they decrease binding ability with IgE and they are of insufficient length to cross-link IgE on the surface of mast cells or basophils, the safety of Tg-rice seeds for patients with JC pollinosis was unclear. METHODS: To verify the safety of Tg-rice seeds in terms of allergies, we investigated the percentage of activated basophils induced by Tg-rice seed extract in the basophil activation test. Blood samples from 29 patients with JC pollinosis were collected. Tg-rice seed extract, non-transgenic wild-type rice seed extract, and Cry j 1 and Cry j 2 were mixed with the blood with reagents. The percentage of activated basophils was assessed by CD203c expression, a basophil activation marker. RESULTS: The percentage of activated basophils after the stimulation with Tg-rice seed extract was 4.5 ± 1.6% (mean ± SD) compared with 62.9 ± 20.2% after Cry j 1- and Cry j 2-stimulation (difference 58.4%, P < 0.001, 95% confidence interval 51.0-65.9%). CONCLUSIONS: The results will contribute to the safety of Tg-rice seeds in terms of allergies.

MicroRNA-200b and -301 are associated with gemcitabine response as biomarkers in pancreatic carcinoma cells.

Chemotherapy resistance (congenital or acquired) is one of the principal challenges for the treatment of pancreatic carcinoma. Recent evidence has demonstrated that epithelial to mesenchymal transition (EMT) is associated with chemoresistance in pancreatic carcinoma cells. However, the molecular mechanism underlying the development of chemoresistance remains unknown, and limited therapeutic options are available. Therefore, to anticipate individual chemosensitivity or acquired chemoresistance for patients with pancreatic carcinoma, predictive biomarkers are urgently required. Extensive evidence suggests that microRNAs (miRNAs) serve a crucial role in regulating EMT. The aim of this study was to examine the potential role of miRNA (miR)­200b and miR­301 in predicting the chemo­responses to treatment for pancreatic carcinoma. The present results demonstrate that miR­200b expression predicted chemo­sensitivity and may have potential as a biomarker. In six different pancreatic carcinoma cell lines (Capan­1, Capan­2, Panc­1, MIAPaCa­2, BxPC­3 and PL45 cells), the expression of miR­200b correlated positively with chemosensitivity. Moreover, the enhanced expression of miR­200b increased chemosensitivity and induced mesenchymal to epithelial transition. Conversely, miR­301 modulated gemcitabine resistance and induced EMT through the downregulation of cadherin 1 expression. In addition, gemcitabine­resistant cells (Capan­2 and Panc­1) exhibited upregulated miR­301 expression and downregulated gemcitabine­induced apoptosis. In summary, these two miRNAs may serve roles as biomarkers in pancreatic carcinoma, miR­200b expression may predict chemosensitivity, and elevated miR­301 expression may have potential applications in the prediction of acquired gemcitabine resistance.

A Novel Near-infrared Fluorescent Protein, iRFP720, Facilitates Transcriptional Profiling of Prostate Cancer Bone Metastasis in Mice.

BACKGROUND: Bone represents a frequent site of prostate cancer metastasis. As the molecular mechanism remains unclear, an accessible animal model is required. MATERIALS AND METHODS: We established a novel murine metastasis model using near-infrared fluorescent protein iRFP720-labelled prostate cancer (PC3) cells. To clarify transcriptional alterations during metastasis, iRFP720-PC3 cells were intracardially injected into male mice. mRNA expression profiles of metastasis in bone using marrow cancer cells extracted by centrifugal separation and cell sorting were compared with those of parental cells by microarray. Differentially expressed genes were analyzed by pathway analysis. RESULTS: We identified 327 and 197 genes being up- and down-regulated, respectively. Pathway analysis revealed that the p53 signaling pathway, extracellular matrix receptor interaction, Mammalian target of rapamycin signaling pathway, cancer-related pathways, small cell lung cancer, and Escherichia coli infection response were altered. CONCLUSION: iRFP720 is useful for in vivo cell detection/isolation. The results of expression analysis may improve prostate cancer treatment strategies.

MicroRNA-203 induces apoptosis by upregulating Puma expression in colon and lung cancer cells.

The present study investigated the relationship between microRNA-203 (miR-203) and the p53 upregulated modulator of apoptosis (Puma) in colon (HCT116) and lung cancer (A549) cells. Colon and lung cancer cell lines were selected for this study since a relationship between p53/miR-203 and p53/Puma has been established in both cancers. In the present study, adriamycin and nutlin-3 were used to activate p53, which induced both miR-203 and Puma expression in HCT116 cells. In contrast, HCT 116 cells with downregulated p53 showed decreased miR-203 and Puma expression. Importantly, we found that overexpressed miR-203 in HCT116 cells resulted in significantly increased Puma expression (P<0.05). Based on these findings, we hypothesized that another limb of the p53/Puma axis depends on miR-203 expression. To further validate this relationship, we used lung cancer cells (A549) and found that activated p53 increased both miR-203 and Puma expression. In addition, we found that Puma expression remained elevated in cells with overexpressed miR-203 in the presence of p53 downregulation. Cumulatively, our data purport that p53 not only increased Puma expression directly, but that it may also do so through miR-203. Additionally, functional studies revealed that miR-203 overexpression induced apoptosis and inhibited cell invasiveness.

Cholangiocarcinoma cell line TK may be useful for the pharmacokinetic study of the chemotherapeutic agent gemcitabine.

Cholangiocarcinoma is a disease with a poor prognosis. A human cholangiocarcinoma cell line, TK, was previously established to enable further understanding of the disease. We conducted this investigation to determine whether or not the TK line is useful for pharmacokinetic study of the chemotherapeutic agent gemcitabine (GEM). Along with the BXPC3 human pancreatic adenocarcinoma cell line, the sensitivity to and effects on the TK cell line of GEM were compared. The influence of deoxycytidine kinase (dCK) transduction was also comparatively investigated. The effects of GEM in terms of drug sensitivity of the TK cell line, cell cycle and levels of transcripts of key enzymes were comparable to the BXPC3 cell line. Responses to the drug were similar in both cell lines. In contrast to pancreatic carcinoma, cell lines for research on cholangiocarcinoma have been limited. This study suggests the application of the TK cell line to the pharmacokinetic study of the chemosensitization of therapeutic drugs, such as GEM.

Morphological study of the TK cholangiocarcinoma cell line with three-dimensional cell culture.

Cholangiocarcinoma is an intractable carcinoma originating from the bile duct epithelium. To gain an understanding of the cell biology of cholangiocarcinoma, in vitro cell culture is valuable. However, well­characterized cell lines are limited. In the present study, the morphology of the TK cholangiocarcinoma cell line was analyzed by three­dimensional culture. Dispersed TK cells were injected into a gelatin mesh scaffold and cultivated for 3­20 days. The morphology of the TK cells was investigated by phase­contrast microscopy, optical microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). TK cells were observed to proliferate three-dimensionally in the scaffold. The cells exhibited a globoid structure and attached to the scaffold. The SEM observation demonstrated typical microvilli and plicae on the surface of the structure. Light microscopy and TEM confirmed intercellular and cell­to­scaffold attachment in the three­dimensional mesh. The culture also exhibited the formation of a duct-like structure covered by structured microvilli. In conclusion, three­dimensional culture of TK cells demonstrated the morphological characteristics of cholangiocarcinoma in vitro. Production of high levels of carbohydrate antigen (CA)19­9, CA50 and carcinoembryonic antigen was previously confirmed in the TK cell line. As a characteristic morphology was demonstrated in the present study, the TK cholangiocarcinoma cell line may be useful as an experimental model for further study of cholangiocarcinoma.

Expression of mRNAs of Urocortin in the STKM-1 gastric cancer cell line.

BACKGROUND: Urocortin is analogous to corticotrophin-releasing factors (CRFs) and a member of the CRF family. We previously demonstrated that urocortin mRNAs were expressed in both human and rat glioma cell lines, and that some of these lines transcribed the receptors. We hypothesize that urocortin might also be expressed in a gastric cancer cell line. The aim of the present study was to clarify the expression of mRNAs of urocortin1 (UCN1), -2 and -3 and of CRF and CRF receptors 1 and 2 in a gastric cancer cell line. MATERIALS AND METHODS: STKM-1 a poorly-differentiated adenocarcinoma cell line was used. Transcripts in the cells were analyzed using cDNA. The fluctuation of mRNA with cellular stress, such as the one caused by a chemotherapeutic agent, serum supplementation and forskolin was examined. RESULTS: Transcripts of UCN1, -2 and CRFR2 were expressed. No changes in transcription of UCN1 and UCN2 were observed with cellular stress. However, expression of CRFR2 mRNA transcripts significantly increased after an initial 24-h exposure to forskolin. CONCLUSION: Expression of the mRNAs of UCN1, 2 and CRFR2 was confirmed in the human gastric cancer cell line, STKM-1. Although the quantity of CRFR2 transcripts varied with forskolin, the overall transcription pattern was not influenced by cellular stimuli.

Expression of mRNAs of urocortin and corticotropin-releasing factor receptors in malignant glioma cell lines.

BACKGROUND: Urocortin and corticotropin-releasing factors (CRFs) and their receptors are expressed in many organs, including the central nervous system. In this study, the expression of mRNAs of urocortin 1, 2, 3, and CRF and CRF receptors 1 and 2 in malignant glioma, was examined. MATERIALS AND METHODS: The RNAs of human and rat glioma cell lines were isolated. Transcripts in these cells were analyzed using cDNA. In addition, the effects of proliferative and cytotoxic stimulation by serum supplementation, ionizing radiation, and the antineoplastic agent temozolomide were investigated. RESULTS: Human and rat cells transcribed urocortin. CRF receptors were detected in human glioma cells. When human KNS42 cells were exposed to stimulation, transcription was altered according to the specific condition. CONCLUSION: Expression of mRNAs of urocortin and CRF receptors was confirmed in human glioma cell lines. Although the quantities of transcripts varied with the proliferative and cytotoxic stimulation, the overall transcription pattern was not influenced by these stimuli.

Expression and distribution of very late antigen-5 in mouse peritoneal macrophages upon ingestion of fibronectin-bound Staphylococcus aureus.

Many pathogens colonize host tissues by binding to the extracellular matrix via their cell surface adhesion molecules, which are called MSCRAMMs (microbial surface components recognizing adhesive matrix molecules). Staphylococcus aureus expresses several of these adhesion molecules, some of which bind to fibronectin. Of these adhesion molecules, fibronectin-binding proteins play a role in the pathogenicity of S. aureus, although it is not yet clear whether they enhance its virulence. We have previously shown that fibronectin-bound S. aureus is efficiently phagocytosed by thioglycolate-induced mouse peritoneal macrophages. Bacterial ingestion is mediated by Very Late Antigen-5 (VLA-5; alpha5beta1 integrin) and is accompanied by the formation of adhesion complexes. Here we show that the expression of VLA-5 is restricted to thioglycolate-induced inflammatory macrophages and is not found in the resident macrophages. When cells were in suspension, alpha5 integrin was not expressed on the surface of either resident or inflammatory macrophages, whereas in adherent cells, this integrin was distributed on the surface of inflammatory but not resident macrophages. A high level of this integrin was present in the cytoplasmic region only in inflammatory macrophages. In agreement with this, fibronectin-mediated phagocytosis of S. aureus was observed only in the inflammatory macrophages. In inflammatory macrophages ingesting fibronectin-bound S. aureus, alpha5 integrin was concentrated close to the phagocytosed bacteria. This change in distribution was not found in macrophages ingesting untreated bacteria. Together with our previous work, these results indicate that, upon ingestion of fibronectin-bound S. aureus, VLA-5 accumulates in the area of phagocytosis in inflammatory macrophages, where it forms adhesion complexes.

Mechanistic effect of NMSO3 on replication of human immunodeficiency virus.

NMSO3, a sulphated sialyl lipid, was evaluated for its efficacy against human immunodeficiency virus type 1 (HIV-1). The compound exhibited concentration-dependent inhibition of HIV-1 replication in primary infection cell culture systems. Substantial inhibition was observed at concentrations of NMSO3 that showed little cytotoxicity. NMSO3 also exhibited anti HIV-1 activity in chronically HIV-1 infected cultures. The production of progeny viruses was completely abolished without cytotoxicity by continuous addition of NMSO3 to chronically infected U937 cells. Furthermore, in attempting to define the inhibitory mechanism of NMSO3, we investigated its effect on several steps of the HIV-1 replication cycle. NMSO3 competes with gp120 for binding to CD4 receptors on cells and inhibits the entry of HIV-1. By epitope analysis of the human CD4 molecule, NMSO3 inhibits the binding of antibodies, which recognize the D1 domain of CD4. Moreover, semi-quantitative reverse transcribed polymerase chain reaction (RT-PCR) showed that the integrated provirus is transcriptionally inactive in NMSO3-treated cells, supporting the lack of progeny in the culture supernatant of chronically HIV-1-infected cells treated with NMSO3. These findings indicate that NMSO3 has a unique mechanism of action against HIV-1 in both primary and chronic infection, and may be a valuable compound for the treatment of HIV-1 infection.