Abstract 4615: Influence of SF3B1 gene mutation is different from that of Sf3B1 inhibitor in colorectal cancer

Purpose: We have reported that SF3B1 gene mutations are rare in colorectal cancer patients and SF3B1 gene mutations in codon 1074 are responsible for resistance to SF3B1 inhibitor (FR901464, FR) at the AACR annual meeting 2013. SF3B1 gene mutations in hematological malignancies are considered to be related to tumor progression. To elucidate the influence by SF3B1 gene mutation in colorectal cancer, we assessed the tumor growth of colorectal cancer cells bearing SF3B1 gene mutation in vitro and in vivo.

ExperimentalDesign: We assessed the tumor growth in vitro and in vivo using FR resistant clones (DLD/FR1, DLD/FR2, DLD/FR3, HCT/FR1, HCT/FR2, and LoVo/FR1) derived from DLD1, HCT116, and LoVo. We also performed microarray analysis of DLD1, DLD/FR1, HCT116, and HCT/FR1 with or without FR for 24 h to compare the change of gene expression by FR or SF3B1 gene mutation.

Results: Doubling time of growth in DLD/FR1, DLD/FR2, HCT/FR1, and HCT/FR2 in vitro was same as their parental cells. However, doubling time of growth in DLD/FR3 and LoVo/FR1 in vitro was longer than their parental cells. In mouse subcutaneous xenograft models, the tumor volume of DLD1/FR1, HCT/FR1, and HCT/FR2 were 61%, 32 %, and 25%, to compared to that of their parental DLD1 or HCT116 one month after inoculation, respectively. Microarray analysis showed the genes and pathways affected by SF3B1 inhibitor and SF3B1 gene mutation did not match at all. Though SF3B1 inhibitor strongly inhibited pathways related to cell cycle, Fanconi anemia, homologous recombination, ubiquitin mediated proteolysis, nucleotide excision repair, oocyte meiosis, basal transcription factors, and endocytosis, SF3B1 gene mutation did not influence these pathways. The genes influenced by SF3B1 gene mutations included MHC class I/II, MHC MYC, BCL2, IL2, and IL10.

Conclusion: Our data indicated SF3B1 gene mutation in colorectal cancer induced disadvantage in cancer progression by the different pathway from SF3B1 inhibitor.

Citation Format: Tomoki Yamano, Shuji Kubo, Nagahide Matsubara, Aya Yano, Naohiro Tomita. Influence of SF3B1 gene mutation is different from that of Sf3B1 inhibitor in colorectal cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4615. doi:10.1158/1538-7445.AM2014-4615

Highly efficient tumor transduction and antitumor efficacy in experimental human malignant mesothelioma using replicating gibbon ape leukemia virus

Retroviral replicating vectors (RRVs) have been shown to achieve efficient tumor transduction and enhanced therapeutic benefit in a wide variety of cancer models. Here we evaluated two different RRVs derived from amphotropic murine leukemia virus (AMLV) and gibbon ape leukemia virus (GALV), in human malignant mesothelioma cells. In vitro, both RRVs expressing the green fluorescent protein gene efficiently replicated in most mesothelioma cell lines tested, but not in normal mesothelial cells. Notably, in ACC-MESO-1 mesothelioma cells that were not permissive for AMLV-RRV, the GALV-RRV could spread efficiently in culture and in mice with subcutaneous xenografts by in vivo fluorescence imaging. Next, GALV-RRV expressing the cytosine deaminase prodrug activator gene showed efficient killing of ACC-MESO-1 cells in a prodrug 5-fluorocytosine dose-dependent manner, compared with AMLV-RRV. GALV-RRV-mediated prodrug activator gene therapy achieved significant inhibition of subcutaneous ACC-MESO-1 tumor growth in nude mice. Quantitative reverse transcription PCR demonstrated that ACC-MESO-1 cells express higher PiT-1 (GALV receptor) and lower PiT-2 (AMLV receptor) compared with normal mesothelial cells and other mesothelioma cells, presumably accounting for the distinctive finding that GALV-RRV replicates much more robustly than AMLV-RRV in these cells. These data indicate the potential utility of GALV-RRV-mediated prodrug activator gene therapy in the treatment of mesothelioma.

Enhanced antitumor efficacy of fiber-modified, midkine promoter-regulated oncolytic adenovirus in human malignant mesothelioma

Oncolytic virotherapy using adenoviruses has potential for therapeutic benefits in malignant mesothelioma. However, the downregulation of coxsackie virus/adenovirus receptor (CAR) expression is frequently a critical rate-limiting factor that impedes the effectiveness of adenovirus serotype 5 (Ad5)-based vectors in many cancer types. We evaluated CAR (Ad5 receptor) and CD46 (adenovirus serotype 35 [Ad35] receptor) expression in six human malignant mesothelioma cell lines. Very low CAR expression was observed in MSTO-211H and NCI-H2052 cells, whereas the other cell lines showed strong expression. In contrast, CD46 was highly expressed in all mesothelioma cell lines. On this basis, we replaced the CAR binding sequence of Ad5 with the CD46 binding sequence of Ad35 in the replication-defective adenoviruses and the tumor-specific midkine promoter-regulated oncolytic adenoviruses. By this fiber modification, the infectivity, virus progeny production, and in vitro cytocidal effects of the adenoviruses were significantly enhanced in low CAR-expressing MSTO-211H and NCI-H2052 cells, also resulting in similar or even higher levels in high CAR-expressing mesothelioma cell lines. In MSTO-211H xenograft models, the fiber-modified oncolytic adenovirus significantly enhanced antitumor effect compared to its equivalent Ad5-based vector. Our data demonstrate that Ad35 fiber modification of binding tropism in a midkine promoter-regulated oncolytic Ad5 vector confers transductional targeting to oncolytic adenoviruses, thereby facilitating more effective treatment of malignant mesothelioma.

Molecular targeting of hepatocyte growth factor by an antagonist, NK4, in the treatment of rheumatoid arthritis

Introduction

Hepatocyte growth factor (HGF) is a potent proangiogenic molecule that induces neovascularization. The HGF antagonist, NK4, competitively antagonizes HGF binding to its receptor. In the present study, we determined the inhibitory effect of NK4 in a rheumatoid arthritis (RA) model using SKG mice.

Methods

Arthritis was induced in SKG mice by a single intraperitoneal injection of β-glucan. Recombinant adenovirus containing NK4 cDNA (AdCMV.NK4) was also injected intravenously at the time of or 1 month after β-glucan injection. Ankle bone destruction was examined radiographically. The histopathologic features of joints were examined using hematoxylin and eosin and immunohistochemical staining. Enzyme-linked immunosorbent assays were used to determine the serum levels of HGF, interferon γ (IFN-γ, interleukin 4 (IL-4) and IL-17 production by CD4⁺ T cells stimulated with allogeneic spleen cells.

Results

The intravenous injection of AdCMV.NK4 into SKG mice suppressed the progression of β-glucan-induced arthritis. Bone destruction was also inhibited by NK4 treatment. The histopathologic findings of the ankles revealed that angiogenesis, inflammatory cytokines and RANKL expression in synovial tissues were significantly inhibited by NK4 treatment. Recombinant NK4 (rNK4) proteins inhibited IFN-γ, IL-4 and IL-17 production by CD4⁺ T cells stimulated with allogeneic spleen cells.

Conclusions

These results indicate that NK4 inhibits arthritis by inhibition of angiogenesis and inflammatory cytokine production by CD4⁺ T cells. Therefore, molecular targeting of angiogenic inducers by NK4 can potentially be used as a novel therapeutic approach for the treatment of RA.

Abstract 4350: Low frequencies of SF3B1 mutations indicate SF3B1 inhibitor as a novel moleculartargeted drug for colorectal cancer

Purpose: FR901464 (FR) is an antitumor agent that specifically binds to and inhibits the function of splicing factor 3B subunit 1 (SF3B1). Higher frequencies of SF3B1 gene mutations and their relevance to cancer progression have been shown in studies of hematological malignancies.

We assessed the frequencies of SF3B1 gene mutations in colorectal cancer (CRC) and the correlation of SF3B1 mutations and FR sensitivity in CRC.

Experimental Design: We measured FR sensitivity in CRC cell lines to establish FR-resistant clones and performed DNA sequencing of all

25 SF3B1 exons in nine CRC cell lines, FR-resistant clones, and 16 CRC patients.

On the basis our results, we performed further DNA sequencing in 80 CRC patients.

Results: The FR IC50 values in all CRC cell lines were < 1ng/ml. Six FR-resistant clones were established: three from DLD1, two from HCT116, and one from LoVo cells. The FR IC50 of the FR-resistant clones was > 500-fold greater than that of their parental cells, although the IC50 of oxaliplatin or 5-fuluorouracil were the same. We found nonsense mutations in exon 10 of DLD1 cells and no significant mutations in the other samples. All the FR-resistant clones had the missense mutations in codon 1073 of exon 22. We found no mutation in exons 10, 22, and 12-15, which were previously reported in hematological malignancies in 80 CRC patients.

Conclusion: Our data indicated the usefulness of the SF3B1 inhibitor as a novel molecular targeted drug for CRC and the other malignancies without codon 1073 mutations.

Citation Format: Tomoki Yamano, Hidenori Nakajima, Satoshi Tsuda, Shuji Kubo, Mie Hamanaka, Masayoshi Kobayashi, Daisuke Yamagishi, Takashi Kuno, Kiyoshi Tsukamoto, Astuko Tamamoto, Masafumi Noda, Nagahide Matsubara, Dave SB Hoon, Naohiro Tomita. Low frequencies of SF3B1 mutations indicate SF3B1 inhibitor as a novel moleculartargeted drug for colorectal cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4350. doi:10.1158/1538-7445.AM2013-4350

102 REPEATED OVARIAN STIMULATIONS BY EXOGENOUS GONADOTROPIN COULD ALTER ATP CONTENT AND MITOCHONDRIAL DISTRIBUTION IN MOUSE OOCYTES

Ovarian stimulation (OS) by exogenous gonadotropin enhances the availability of mammalian oocytes but compromises their developmental competence (Combelles and Albertini 2003 Biol. Reprod. 68, 812–821). Recently, several studies have reported mitochondrial function-related abnormalities in oocytes after single and repeated OSs. Because mitochondria can directly influence fertilization outcomes (El Shourbagy et al. 2006 Reproduction 131, 233–245), this study aimed to determine the relationship between mitochondria-related parameters and developmental competence on the basis of ATP content, mitochondrial DNA (mtDNA) copy number, mitochondrial distribution, and IVF results for oocytes after repeated OSs. Ovulated oocytes were recovered from ICR female mice treated with 7.5 IU of eCG and 5 IU of hCG at an interval of 48 h in 1 (control) to 3 stimulation cycles, which were performed at intervals of either 5 or 10 d (n = 15–25 in each treatment group). The ATP content in oocytes was determined using a luminometer and commercial kits (BacTiter-Glo; Promega, WI, USA; n = 15–29 in each treatment group). The mtDNA copy number in oocytes was quantified by performing absolute quantification with real-time PCR (n = 4–8 in each treatment group). Mitochondrial distribution in oocytes stained by rhodamine123 was observed under a confocal microscope (n = 12–26 in each treatment group). These analyses were performed only for morphologically normal oocytes. The data were analyzed by one-way ANOVA, followed by Fisher’s least significant difference, or by the chi-square test. Some mice did not ovulate in the third stimulation cycle for both intervals (5-d interval, 32%; 10-d interval, 80%). The mean numbers of ovulated oocytes gradually decreased with progression of the stimulation cycles. The ATP content of the oocytes significantly decreased both in the second and third stimulation cycles, performed with a 5-d interval (control, 1.038 ± 0.117 pmol; second cycle, 0.852 ± 0.189 pmol; third cycle, 0.932 ± 0.272 pmol). The mean mtDNA copy number in oocytes did not change significantly but varied widely in the third stimulation cycle (control, 146 000 ± 21 000; 5-d interval, 135 000 ± 35 000; 10-d interval: 148 000 ± 50 000; mean ± SD). The mitochondrial staining patterns were classified into homogeneous, aggregation, and perinuclear accumulation. The rates of aggregation and perinuclear accumulation increased after repeated stimulation cycles. The blastocyst rates did not significantly differ among the treatment groups after IVF (75–82%). Repeated OSs not only decreased the number of ovulated oocytes but also caused changes related with mitochondrial function, even in the morphologically normal ovulated oocytes. Translocation of active mitochondria, which are associated with energy production, has some functional correlation with successful pre-implantation development (Suzuki et al. 2006 J. Mamm. Ova. Res. 23, 128–134). Changes in mitochondrial distribution might compensate for the negative effect of the decrease in ATP content and low mtDNA copy number after repeated OSs to help reach the blastocyst stage.

Suppression of spurious mode oscillation in mega-watt 77-GHz gyrotron as a high quality probe beam source for the collective Thomson scattering in LHD

Collective Thomson scattering (CTS) diagnostic requires a strong probing beam to diagnose a bulk and fast ion distribution function in fusion plasmas. A mega-watt gyrotron for electron cyclotron resonance heating is used as a probing beam in the large helical device. Spurious mode oscillations are often observed during the turning on/off phase of the modulation. The frequency spectra of the 77-GHz gyrotron output power have been measured, and then one of the spurious modes, which interferes with the CTS receiver system, is identified as the TE(17,6) mode at the frequency of 74.7 GHz. The mode competition calculation indicates that the increase of the magnetic field strength at the gyrotron resonator can avoid such a spurious mode and excite only the main TE(18,6) mode. The spurious radiation at the 74.7 GHz is experimentally demonstrated to be suppressed in the stronger magnetic field than that optimized for the high-power operation.

Cytosine-phosphate-guanosine-DNA induces CD274 expression in human B cells and suppresses T helper type 2 cytokine production in pollen antigen-stimulated CD4-positive cells

Co-stimulatory molecules are important for regulating T cell activation and immune response. CD274 [programmed death ligand 1 (PD-L1), B7-H1] has emerged as an important immune modulator that can block T cell receptor signalling. We have investigated whether PD-L1 and other co-stimulatory ligands could be expressed in human B cells stimulated by cytosine-phosphate-guanosine (CpG)-DNA. CpG-DNA strongly induced the co-inhibitory molecule ligand, PD-L1, of human B cells. Results show that nuclear factor-kappa B (NF-κB) signalling is involved directly in CpG-DNA-induced PD-L1 expression in human B cells. We sought to determine the effect of CpG-DNA-treated B cells on T helper type 2 (Th2) cytokine production in Cry j 1 (Japanese pollen antigen)-stimulated human CD4-positive cells from patients with seasonal allergic rhinitis caused by Japanese cedar pollen. CpG-DNA-treated B cells reduced Cry j 1-induced interleukin (IL)-5 and IL-13 production in CD4-positive cells. When the binding of PD-1 to PD-L1 was inhibited by PD-1-immunoglobulin (Ig), this chimera molecule reversed the previously described reductions in IL-5 and IL-13 production. In contrast, the CpG B-treated B cells increased both interferon (IFN)-γ and IL-12 production in the presence of Cry j 1-stimulated CD4-positive cells. CpG-DNA simultaneously reduced the expression of B7RP-1 [also known as inducible co-stimulator ligand (ICOSL), B7-H2] and the ligand of CD30 (CD30L). These results indicate that CpG-DNA induces co-inhibitory molecule ligand PD-L1 expression in human B cells and PD-L1 can suppress Th2 cytokine production in Cry j 1-stimulated CD4-positive cells, while CpG-DNA increased Th1 cytokine production and reduced the expression of co-stimulatory molecule ligands that can promote Th2 inflammatory responses.

[Metastatic lung tumor from colon cancer with cavitation: report of a case]

A 55-year-old man underwent rectal amputation for rectal cancer in August 2005. A tiny thin-walled cavity lesion in his left S1+2 was found on computed tomography (CT) of the chest in November 2008. The cavity lesion in the left S1+2 gradually increased in size over 3 months and positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) showed FDG accumulation at the lesion. Videoassisted thoracoscopic (VATS) wedge resection was performed to make a definite diagnosis in March 2009. The pathological findings revealed a metastatic lung tumor from the rectal cancer. It is necessary to consider the possibility of metastatic lung tumors in a case with the cavity lesions especially in patients with a history of colon cancer.

SAP155-mediated splicing of FUSE-binding protein-interacting repressor serves as a molecular switch for c-myc gene expression

The Far UpStream Element (FUSE)-binding protein-interacting repressor (FIR), a c-myc transcriptional suppressor, is alternatively spliced removing the transcriptional repression domain within exon 2 (FIRΔexon2) in colorectal cancers. SAP155 is a subunit of the essential splicing factor 3b (SF3b) subcomplex in the spliceosome. This study aims to study the significance of the FIR-SAP155 interaction for the coordination of c-myc transcription, pre-mRNA splicing, and c-Myc protein modification, as well as to interrogate FIRΔexon2 for other functions relating to altered FIR pre-mRNA splicing. Knockdown of SAP155 or FIR was used to investigate their reciprocal influence on each other and on c-myc transcription, pre-mRNA splicing, and protein expression. Pull down from HeLa cell nuclear extracts revealed the association of FIR, FIRΔexon2, and SF3b subunits. FIR and FIRΔexon2 were coimmunoprecipitated with SAP155. FIR and FIRΔexon2 adenovirus vector (Ad-FIR and Ad-FIRΔexon2, respectively) were prepared to test for their influence on c-myc expression. FIR, SAP155, SAP130, and c-myc were coordinately upregulated in human colorectal cancer. These results reveal that SAP155 and FIR/FIRΔexon2 form a complex and are mutually upregulating. Ad-FIRΔexon2 antagonized Ad-FIR transcriptional repression of c-myc in HeLa cells. Because FIRΔexon2 still carries RRM1 and RRM2 and binding activity to FUSE, it is able to displace repression competent FIR from FUSE in electrophoretic mobility shift assays, thus thwarting FIR-mediated transcriptional repression by FUSE. Thus aberrant FIRΔexon2 production in turn sustained c-Myc expression. In conclusion, altered FIR and c-myc pre-mRNA splicing, in addition to c-Myc expression by augmented FIR/FIRΔexon2-SAP155 complex, potentially contribute to colorectal cancer development.

Deficiency of Fyn protein is prerequisite for apoptosis induced by Src family kinase inhibitors in human mesothelioma cells

Malignant mesothelioma is an aggressive tumor arising from mesothelial cells of serous membranes. Src family kinases (SFKs) have a pivotal role in cell adhesion, proliferation, survival and apoptosis. Here, we examined the effect of SFK inhibitors in NCI-H2052, ACC-MESO-4 and NCI-H28 cells, mesothelioma cell lines and Met5A, a human non-malignant mesothelial cell line. We found that PP2, a selective SFK inhibitor, inhibited SFK activity and induced apoptosis mediated by caspase-8 in NCI-H28 but not Met5A, NCI-H2052 and ACC-MESO-4 cells. Src, Yes, Fyn and Lyn protein, which are members of the SFK, were expressed in these cell lines, whereas NCI-H28 cells were deficient in Fyn protein. Small interfering RNA (siRNA) targeting Fyn facilitated PP2-induced apoptosis mediated by caspase-8 in NCI-H2052 and ACC-MESO-4 cells. PP2 reduced Lyn protein levels and suppressed SFK activity in all mesothelioma cell lines. Lyn siRNA induced caspase-8 activation and apoptosis in NCI-H28 cells but not in NCI-H2052 and ACC-MESO-4 cells. However, double RNA interference knockdown of Fyn and Lyn induced apoptosis accompanied by caspase-8 activation in NCI-H2052 and ACC-MESO-4 cells. Dasatinib, an inhibitor of multi-tyrosine kinases including SFK, also inhibited SFK activity and induced reduction of Lyn protein levels, caspase-8 activation and apoptosis in NCI-H28 cells but not in other cell lines. Present study suggests that SFK inhibitors induce caspase-8-dependent apoptosis caused by reduction of Lyn protein in Fyn-deficient mesothelioma cells.

Observation of long-distance radial correlation in toroidal plasma turbulence

This Letter presents the discovery of macroscale electron temperature fluctuations with a long radial correlation length comparable to the plasma minor radius in a toroidal plasma. Their spatiotemporal structure is characterized by a low frequency of ∼1-3  kHz, ballistic radial propagation, a poloidal or toroidal mode number of m/n=1/1 (or 2/1), and an amplitude of ∼2% at maximum. Nonlinear coupling between the long-range fluctuations and the microscopic fluctuations is identified. A change of the amplitude of the long-range fluctuation is transmitted across the plasma radius at the velocity which is of the order of the drift velocity.

Ischemia-induced neural stem/progenitor cells in the pia mater following cortical infarction

Increasing evidence shows that neural stem/progenitor cells (NSPCs) can be activated in the nonconventional neurogenic zones such as the cortex following ischemic stroke. However, the precise origin, identity, and subtypes of the ischemia-induced NSPCs (iNSPCs), which can contribute to cortical neurogenesis, is currently still unclear. In our present study, using an adult mouse cortical infarction model, we found that the leptomeninges (pia mater), which is widely distributed within and closely associated with blood vessels as microvascular pericytes/perivascular cells throughout central nervous system (CNS), have NSPC activity in response to ischemia and can generate neurons. These observations indicate that microvascular pericytes residing near blood vessels that are distributed from the leptomeninges to the cortex are potential sources of iNSPCs for neurogenesis following cortical infarction. In addition, our results propose a novel concept that the leptomeninges, which cover the entire brain, have an important role in CNS restoration following brain injury such as stroke.

Replication-competent retrovirus vector-mediated prodrug activator gene therapy in experimental models of human malignant mesothelioma

Replication-competent retrovirus (RCR) vectors have been shown to achieve significantly enhanced tumor transduction efficiency and therapeutic efficacy in various cancer models. In the present study, we investigated RCR vector-mediated prodrug activator gene therapy for the treatment of malignant mesothelioma, a highly aggressive tumor with poor prognosis. RCR-GFP vector expressing the green fluorescent protein marker gene successfully infected and efficiently replicated in human malignant mesothelioma cell lines, as compared with non-malignant mesothelial cells in vitro. In mice with pre-established subcutaneous tumor xenografts, RCR-GFP vector showed robust spread throughout entire tumor masses after intratumoral administration. Next, RCR-cytosine deaminase (RCR-CD), expressing the yeast CD prodrug activator gene, showed efficient transmission of the prodrug activator gene associated with replicative spread of the virus, resulting in efficient killing of malignant mesothelioma cells in a prodrug 5-fluorocytosine (5FC)-dose dependent manner in vitro. After a single intratumoral injection of RCR-CD followed by intraperitoneal administration of 5FC, RCR vector-mediated prodrug activator gene therapy achieved significant inhibition of subcutaneous tumor growth, and significantly prolonged survival in the disseminated peritoneal model of malignant mesothelioma. These data indicate the potential utility of RCR vector-mediated prodrug activator gene therapy in the treatment of malignant mesothelioma.

Intracellular estrogen receptor-binding fragment-associated antigen 9 exerts in vivo tumor-promoting effects via its coiled-coil region

Estrogen receptor-binding fragment-associated antigen 9 (EBAG9) is a tumor-promoting factor of largely unknown function. To assess a causative role of EBAG9 in advanced malignancies, we generated the EG7-OVA and MethA murine tumor cell lines that stably express full-length or truncated EBAG9 protein, using retroviral-mediated gene transduction. Upon subcutaneous inoculation into immunocompetent mice, both cell lines showed marked acceleration of in vivo tumor growth when full-length EBAG9 was overexpressed. Interestingly, deletion of the coiled-coil region, thereby producing truncated EBAG9 protein, abolished the tumor-acceleration effect, establishing the importance of this domain in EBAG9-mediated tumor promotion. However, there was no alteration in in vitro cell proliferation or expression levels of MHC class I and co-stimulatory molecules believed to play a role in immune evasion of tumor cells in these tumor cell lines expressing full-length or truncated EBAG9 protein. Furthermore, both full-length and truncated EBAG9 proteins showed a predominantly cytoplasmic localization in the tumor cells. Collectively, these results suggest that EBAG9 overexpression can be causative in enhancing the malignant properties of tumor cells, and that tumor promotion likely requires EBAG9 intracellular association with as yet unidentified binding partners via the coiled-coil region.

PPARγ expression is increased in systemic lupus erythematosus patients and represses CD40/CD40L signaling pathway

Systemic lupus erythematosus (SLE) is a heterogeneous disease involving several immune cell types and pro-inflammatory signals, including the one triggered by binding of CD40L to the receptor CD40. Peroxisome-proliferator activated receptor gamma (PPARγ) is a transcription factor with anti-inflammatory properties. Here we investigated whether CD40 and PPARγ could exert opposite effects in the immune response and the possible implications for SLE. Increased PPARγ mRNA levels were detected by real-time PCR in patients with active SLE, compared to patients with inactive SLE PPARγ/GAPDH mRNA = 2.21 ± 0.49 vs. 0.57 ± 0.14, respectively (p < 0.05) or patients with infectious diseases and healthy subjects (p < 0.05). This finding was independent of the corticosteroid therapy. We further explored these observations in human THP1 and in SLE patient-derived macrophages, where activation of CD40 by CD40L promoted augmented PPARγ gene transcription compared to non-stimulated cells (PPARγ/GAPDH mRNA = 1.14 ± 0.38 vs. 0.14 ± 0.01, respectively; p < 0.05). This phenomenon occurred specifically upon CD40 activation, since lipopolysaccharide treatment did not induce a similar response. In addition, increased activity of PPARγ was also detected after CD40 activation, since higher PPARγ-dependent transcription of CD36 transcription was observed. Furthermore, CD40L-stimulated transcription of CD80 gene was elevated in cells treated with PPARγ-specific small interfering RNA (small interfering RNA, siRNA) compared to cells treated with CD40L alone (CD80/GAPDH mRNA = 0.11 ± 0.04 vs. 0.05 ± 0.02, respectively; p < 0.05), suggesting a regulatory role for PPARγ on the CD40/CD40L pathway. Altogether, our findings outline a novel mechanism through which PPARγ regulates the inflammatory signal initiated by activation of CD40, with important implications for the understanding of immunological mechanisms underlying SLE and the development of new treatment strategies.

Complete regression of human malignant mesothelioma xenografts following local injection of midkine promoter-driven oncolytic adenovirus

BACKGROUND

Malignant mesothelioma is a highly aggressive tumor with poor prognosis. We hypothesized that the tumor-specific midkine (Mdk) promoter could confer transcriptional targeting to oncolytic adenoviruses for effective treatment of malignant mesothelioma.

METHODS

We analysed Mdk expression by quantitative reverse transcription-polymerase chain reaction in six human mesothelioma cell lines, and tested Mdk promoter activity by luciferase reporter assay. On the basis of these data, we constructed a replication-selective oncolytic adenovirus designated AdMdk-E1-iresTK. This virus contains a Mdk promoter-driven adenoviral E1 gene and herpes simplex virus-thymidine kinase (TK) suicide gene and cytomagalovirus promoter-driven enhanced green fluorescent protein marker gene. Selectivity of viral replication and cytolysis were characterized in normal versus mesothelioma cells in vitro, and intratumoral spread and antitumor efficacy were investigated in vivo.

RESULTS

Mdk promoter activity was restricted in normal cells, but highly activated in mesothelioma cell lines. AdMdk-E1-iresTK was seen to efficiently replicate, produce viral progeny and spread in multiple mesothelioma cell lines. Lytic spread of AdMdk-E1-iresTK mediated the efficient killing of these mesothelioma cells, and its in vitro cytocidal effect was significantly enhanced by treatment with the prodrug, ganciclovir. Intratumoral injection of AdMdk-E1-iresTK caused complete regression of MESO4 and MSTO human mesothelioma xenografts in athymic mice. In vivo fluorescence imaging demonstrated intratumoral spread of AdMdk-E1-iresTK-derived signals, which vanished after tumor eradication.

CONCLUSIONS

These data indicate that transcriptional targeting of viral replication by the Mdk promoter represents a promising general strategy for oncolytic virotherapy of cancers with up-regulated Mdk expression, including malignant mesothelioma.

Bone marrow mononuclear cells promote proliferation of endogenous neural stem cells through vascular niches after cerebral infarction

Increasing evidence shows that administration of bone marrow mononuclear cells (BMMCs) is a potential treatment for various ischemic diseases, such as ischemic stroke. Although angiogenesis has been considered primarily responsible for the effect of BMMCs, their direct contribution to endothelial cells (ECs) by being a functional elements of vascular niches for neural stem/progenitor cells (NSPCs) has not been considered. Herein, we examine whether BMMCs affected the properties of ECs and NSPCs, and whether they promoted neurogenesis and functional recovery after stroke. We compared i.v. transplantations 1 x 10(6) BMMCs and phosphate-buffered saline in mice 2 days after cortical infarction. Systemically administered BMMCs preferentially accumulated at the postischemic cortex and peri-infarct area in brains; cell proliferation of ECs (angiogenesis) at these regions was significantly increased in BMMCs-treated mice compared with controls. We also found that endogenous NSPCs developed in close proximity to ECs in and around the poststroke cortex and that ECs were essential for proliferation of these ischemia-induced NSPCs. Furthermore, BMMCs enhanced proliferation of NSPCs as well as ECs. Proliferation of NSPCs was suppressed by additional treatment with endostatin (known to inhibit proliferation of ECs) following BMMCs transplantation. Subsequently, neurogenesis and functional recovery were also promoted in BMMCs-treated mice compared with controls. These results suggest that BMMCs can contribute to the proliferation of endogenous ischemia-induced NSPCs through vascular niche regulation, which includes regulation of endothelial proliferation. In addition, these results suggest that BMMCs transplantation has potential as a novel therapeutic option in stroke treatment.

[Simultaneously treated thymoma and lung cancer; report of a case]

A 74-year-old man was admitted to our hospital in order to treat a mediastinal mass and 2 ground-glass attenuations in the right upper lobe detected by chest X-ray and computed tomography (CT). Partial resection of right lung and thymectomy were performed. The mediastinal mass and 2 ground-glass attenuations in the right upper lobe proved to be thymoma and bronchioloalveolar carcinomas, respectively by pathology.

Collective Thomson scattering of a high power electron cyclotron resonance heating beam in LHD (invited)

Collective Thomson scattering (CTS) system has been constructed at LHD making use of the high power electron cyclotron resonance heating (ECRH) system in Large Helical Device (LHD). The necessary features for CTS, high power probing beams and receiving beams, both with well defined Gaussian profile and with the fine controllability, are endowed in the ECRH system. The 32 channel radiometer with sharp notch filter at the front end is attached to the ECRH system transmission line as a CTS receiver. The validation of the CTS signal is performed by scanning the scattering volume. A new method to separate the CTS signal from background electron cyclotron emission is developed and applied to derive the bulk and high energy ion components for several combinations of neutral beam heated plasmas.

Improvements of data quality of the LHD Thomson scattering diagnostics in high-temperature plasma experiments

In Large Helical Device (LHD) experiments, an electron temperature (T(e)) more than 15 keV has been observed by the yttrium-aluminum-garnet (YAG) laser Thomson scattering diagnostic. Since the LHD Thomson scattering system has been optimized for the temperature region, 50 eV≤T(e)≤10 keV, the data quality becomes worse in the higher T(e) region exceeding 10 keV. In order to accurately determine T(e) in the LHD high-T(e) experiments, we tried to increase the laser pulse energy by simultaneously firing three lasers. The technique enables us to decrease the uncertainties in the measured T(e). Another signal accumulation method was also tested. In addition, we estimated the influence of high-energy electrons on T(e) obtained by the LHD Thomson scattering system.

Observation of reversed-shear Alfvén eigenmodes excited by energetic ions in a helical plasma

Reversed-shear Alfvén eigenmodes were observed for the first time in a helical plasma having negative q₀'' (the curvature of the safety factor q at the zero shear layer). The frequency is swept downward and upward sequentially via the time variation in the maximum of q. The eigenmodes calculated by ideal MHD theory are consistent with the experimental data. The frequency sweeping is mainly determined by the effects of energetic ions and the bulk pressure gradient. Coupling of reversed-shear Alfvén eigenmodes with energetic ion driven geodesic acoustic modes generates a multitude of frequency-sweeping modes.

Establishment of in vivo fluorescence imaging in mouse models of malignant mesothelioma

Malignant mesothelioma is a highly aggressive tumor with poor prognosis, and new treatment paradigms are urgently needed. For testing preclinical efficacy of new therapeutic agents, establishment of appropriate animal models is crucial. We developed in vivo fluorescence imaging models for human malignant mesothelioma in mice using tumor cells engineered to express fluorescent proteins (EGFP, mRFP, mCherry, and mPlum) by lentiviral vectors. Among these fluorescent proteins, the expression of mCherry protein in the transduced tumor cells was shown to be robust and stable both in vitro and in vivo. In both, peritoneally disseminated and orthotopic pleural mesothelioma models, mCherry-positive tumors were sensitively detected and tumor growth was successfully monitored. This represents the first study to achieve sensitive tumor detection and tracking of tumor growth and development in the malignant mesothelioma mouse models by non-invasive in vivo fluorescence imaging. These imaging models can be versatile and powerful tools to explore new treatment paradigms for malignant mesothelioma.

Removal of a cavernous hemangioma in the orbital apex via the endoscopic transnasal approach: a case report

INTRODUCTION

The aim of this study is to describe the case of a cavernous hemangioma extending from the orbital apex to the pterygopalatine fossa that was completely removed via an endoscopic transnasal approach.

CASE REPORT

We report the case of a 48-year-old man who presented with right hemianopsia of the left eye. MRI revealed a 1.5 x 1.1 cm mass lesion extending from the infero-medial part of the left orbital apex to the pterygopalatine fossa. Removal of the lesion was performed via the endoscopic transnasal approach. Using this approach, a wide operative view of the entire extent of the lesion from the optic canal to the orbital apex and the pterygopalatine fossa was obtained, and complete removal of the lesion was performed safely. The pathological diagnosis was cavernous hemangioma.

CONCLUSION

The endoscopic transnasal approach is a safe, effective, and less invasive therapeutic modality for the removal of lesions extending from the infero-medial part of the left orbital apex to the pterygopalatine fossa. With appropriate patient selection, this approach improves access and visualization, and it enables performance of operative procedures with much less risk than the conventional microscopic transcranial or transfacial approaches.

Novel antagonists for proteinase-activated receptor 2: inhibition of cellular and vascular responses in vitro and in vivo

BACKGROUND AND PURPOSE

Proteinase-activated receptor 2 (PAR(2)) is a G-protein coupled receptor associated with many pathophysiological functions. To date, the development of PAR(2) antagonists has been limited. Here, we identify a number of novel peptide-mimetic PAR(2) antagonists and demonstrate inhibitory effects on PAR(2)-mediated intracellular signalling pathways and vascular responses.

EXPERIMENTAL APPROACH

The peptide-mimetic compound library based on the structures of PAR(2) agonist peptides were screened for inhibition of PAR(2)-induced calcium mobilisation in human keratinocytes. Representative compounds were further evaluated by radioligand binding and inhibition of NFkappaB transcriptional activity and IL-8 production. The vascular effects of the antagonists were assessed using in vitro and in vivo models.

KEY RESULTS

Two compounds, K-12940 and K-14585, significantly reduced SLIGKV-induced Ca(2+) mobilisation in primary human keratinocytes. Both K-12940 and K-14585 exhibited competitive inhibition for the binding of a high-affinity radiolabelled PAR(2)-ligand, [(3)H]-2-furoyl-LIGRL-NH(2), to human PAR(2) with K(i) values of 1.94 and 0.627 microM respectively. NFkappaB reporter activity and IL-8 production were also significantly reduced. Furthermore, relaxation of rat-isolated aorta induced by SLIGRL-NH(2) was inhibited competitively by K-14585. K-14585 also significantly lowered plasma extravasation in the dorsal skin of guinea pigs and reduced salivation in mice.

CONCLUSIONS AND IMPLICATIONS

K-12940 and K-14585 antagonized PAR(2) competitively, resulting in inhibition of PAR(2)-mediated signalling and physiological responses both in vitro and in vivo. These peptide-mimetic PAR(2) antagonists could be useful in evaluating PAR(2)-mediated biological events and might lead to a new generation of therapeutically useful antagonists.