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Chromosome band 8q24 is the most frequently amplified locus in various types of cancers. MYC has been identified as the primary oncogene at the 8q24 locus, whereas a long noncoding gene, PVT1, which lies adjacent to MYC, has recently emerged as another potential oncogenic regulator at this position. In this study, we established and characterized a novel cell line, AMU-ML2, from a patient with diffuse large B-cell lymphoma (DLBCL), displaying homogeneously staining regions at the 8q24 locus. Fluorescence in situ hybridization clearly detected an elevation in MYC copy numbers corresponding to the homogenously staining region. In addition, a comparative genomic hybridization analysis using high-resolution arrays revealed that the 8q24 amplicon size was 1.4 Mb, containing the entire MYC and PVT1 regions. We also demonstrated a loss of heterozygosity for TP53 at 17p13 in conjunction with a TP53 frameshift mutation. Notably, AMU-ML2 cells exhibited resistance to vincristine, and cell proliferation was markedly inhibited by MYC-shRNA-mediated knockdown. Furthermore, genes involved in cyclin D, mTOR, and Ras signaling were downregulated following MYC knockdown, suggesting that MYC expression was closely associated with tumor cell growth. In conclusion, AMU-ML2 cells are uniquely characterized by homogenously staining regions at the 8q24 locus, thus providing useful insights into the pathogenesis of DLBCL with 8q24 abnormalities.

Multiple myeloma (MM) cells are derived from mature B cells based on immunoglobulin heavy chain (IgH) gene analysis. The onset of MM is often caused by a reciprocal chromosomal translocation (cTr) between chr 14 with IgH and chr 11 with CCND1. We propose that mature B cells gain the potential to transform by reprograming, and the resulting chromosomal aberrations subsequently cause the development of abnormal B cells as a myeloma-initiating cell during B cell redifferentiation. To study myeloma-initiating cells, we previously established normal B cell-derived induced pluripotent stem cells (BiPSCs: BiPSC13 and MIB2-6); these BiPSCs have the same VDJ rearrangement of IgH as the original B lymphocytes and induce the expression of activation-induced cytidine deaminase (AID) by the Tet-off system (Sci Rep, 2017). Subsequently, we established two BiPSCs with reciprocal cTr t(11;14) using the CRISPR/Cas9 system; the cleavage site were located in the IgH Eμ region of either the VDJ rearranged allele or non-rearranged allele of IgH and the 5′-upsteam region of the CCND1 (two types of BiPSC13 with t(11;14) and MIB2-6 with t(11;14)). Furthermore, p53 was deleted using the CRISPR/Cas9 system in BiPSC13 with t(11;14) carrying the DJ-rearranged allele of IgH that reciprocally translocated with CCND1 (G28). All these BiPSCs differentiated into hematopoietic progenitor cells (HPCs) (Sci Res, 2021). Next, we created AID fused with the hormone-binding domain of the estrogen receptor T2 mutant (AID-ER) to analyze the function of AID. The ER sequence of pCAG-ERT2CreERT2 (Addgene # 13777) was amplified by PCR and cloned into the downstream part of the TREtight promoter of pRetroX-Tight-Hyg as an open reading frame using an In-Fusion HD cloning kit. The ER sequence was also cloned into the same vector as a negative control for the analysis of AID function. These vectors were packaged into a retrovirus using gp293 and pMD2.G, and the viruses were infected into HEK293 cells expressing Tet-off transcription factor and fluorescence-deficient EGFP, in which the artificially-introduced stop codon was at the 106 thcodon of the EGFP gene. The expression of AID-ER fusion protein was induced by removal of doxycycline three days before analysis. AID activity was induced by the addition of 4-hydroxytamoxifen, an agonist of ER mutants, one day before analysis. Therefore, AID activity was monitored by detecting the frequency of EGFP-positive cells, i.e., the recovery of fluorescence, by flow-cytometry. Mutation of the artificial stop codon (from TAG to TAC; from stop codon to Tyrosine) was confirmed by sequencing the EGFP DNA amplified by PCR from the sorted EGFP-positive cells. Subsequently, we examined the introduction of mutated KRAS and NRAS genes into G28, because the most frequently occurring mutations in patients with MM are in KRAS and NRAS. Mutated KRAS (G12A) and NRAS (G13D) were amplified by RT-PCR from poly (A) mRNA of MM.1S and KMM1 of MM cell lines, respectively. After confirming the sequence of these mutants, the mutant cDNA of KRAS or NRAS was cloned into pRetroX-Tight-Hyg in combination with AID-ER. These two vectors were packaged into retroviruses, following which the viruses were infected into BiPSC13 with t(11;14) expressing Tet-off transcription factors, respectively. These BiPSCs also differentiated into HPCs. However, unlike cord blood, these HPCs did not differentiate into B lymphocytes by co-culture with BM stromal cell (MS-5). Therefore, further ingenuity is required to differentiate the BiPSC-derived HPCs into B lymphocytes. Disclosures No relevant conflicts of interest to declare.

OBJECTIVE Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by progressive occlusion of the internal carotid artery and the secondary formation of collateral vessels. Patients with MMD have ischemic attacks or intracranial bleeding, but the disease pathophysiology remains unknown. In this study, the authors aimed to identify a gene expression profile specific to the intracranial artery in MMD. METHODS This was a single-center, prospectively sampled, retrospective cohort study. Microsamples of the middle cerebral artery (MCA) were collected from patients with MMD (n = 11) and from control patients (n = 9). Using microarray techniques, transcriptome-wide analysis was performed. RESULTS Comparison of MCA gene expression between patients with MMD and control patients detected 62 and 26 genes whose expression was significantly (p < 0.001 and fold change > 2) up- or downregulated, respectively, in the MCA of MMD. Gene set enrichment analysis of genes expressed in the MCA of patients with MMD revealed positive correlations with genes involved in antigen processing and presentation, the dendritic cell pathway, cytokine pathway, and interleukin-12 pathway, and negative correlations with genes involved in oxidative phosphorylation and DNA repair. Microarray analysis was validated by quantitative polymerase chain reaction. CONCLUSIONS Transcriptome-wide analysis showed upregulation of genes for immune responses and downregulation of genes for DNA repair and oxidative phosphorylation within the intracranial artery of patients with MMD. These findings may represent clues to the pathophysiology of MMD.

Malignant pleural mesothelioma (MPM), an asbestos‐related occupational disease, is an aggressive and incurable tumor of the thoracic cavity. Despite recent advances in MPM treatment, overall survival of patients with MPM is very low. Recent studies have implicated that PI3K/Akt signaling is involved in MPM cell survival and development. To investigate the effects of Akt inhibitors on MPM cell survival, we examined the effects of nine selective Akt inhibitors, namely, afuresertib, Akti‐1/2, AZD5363, GSK690693, ipatasertib, MK‐2206, perifosine, PHT‐427, and TIC10, on six MPM cell lines, namely, ACC‐MESO‐4, Y‐MESO‐8A, MSTO‐211H, NCI‐H28, NCI‐H290, and NCI‐H2052, and a normal mesothelial cell line MeT‐5A. Comparison of IC 50 values of the Akt inhibitors showed that afuresertib, an ATP‐competitive specific Akt inhibitor, exerted tumor‐specific effects on MPM cells. Afuresertib significantly increased caspase‐3 and caspase‐7 activities and apoptotic cell number among ACC‐MESO‐4 and MSTO‐211H cells. Moreover, afuresertib strongly arrested the cell cycle in the G1 phase. Western blotting analysis showed that afuresertib increased the expression of p21WAF 1/ CIP 1 and decreased the phosphorylation of Akt substrates, including GSK‐3β and FOXO family proteins. These results suggest that afuresertib‐induced p21 expression promotes G1 phase arrest by inducing FOXO activity. Furthermore, afuresertib significantly enhanced cisplatin‐induced cytotoxicity. Interestingly, results of gene set enrichment analysis showed that afuresertib modulated the expression E2F1 and MYC, which are associated with fibroblast core serum response. Together, these results suggest that afuresertib is a useful anticancer drug for treating patients with MPM.

The cellular origin of multiple myeloma (MM) has not yet been identified. Based on immunoglobulin heavy chain (IgH) gene analysis, myeloma cells are derived from mature B cells. Chromosomal aberrations such as trisomy and chromosomal translocation (cTr) play a critical role in the early tumorigenesis of MM. We hypothesized that the abnormal cells from which myeloma cells originate might be mature B lymphocytes with chromosomal or genetic changes in the reprogrammed state that enable them to acquire the potential to become tumors in the process of redifferentiation into B lymphocytes. We established induced pluripotent stem cells (iPSs) from normal B lymphocytes (BiPSCs: BiPSC13 & MIB2-6); these BiPSCs have the same VDJ rearrangement of IgH as the original B lymphocytes and differentiate into CD34+/CD38- hematopoietic progenitor cells co-culture with stromal cells, AGM-S3 (Sci Rep, 2017). We then established a method to induce reciprocal cTr t(11;14), which is a reciprocal cTr between IgH and CCND1 and the most frequent cTr in MM, using the CRISPR/Cas9 system; cTr was induced by infection of IgH-CCND1 lentiCRISPRv2 lentivirus, which targets the human IgH Eµ region and 13kb upstream of the CCND1 coding sequence, to BiPSCs (Oncol Lett, 2019). Subsequently, we established cell lines carrying reciprocal cTr t(11;14) between CCND1 and either an allele in which VDJ rearrangement of IgH had been completed or an allele in which VDJ rearrangement had not been completed (stopped at DJ joining) in BiPSC13 t(11;14) (AZ & AX) and MIB2-6 t(11;14) (BC & BG), respectively. These BiPSCs differentiated into CD34+/CD38-/CD45+/-/CD43+/- hematopoietic progenitors cells in co-culture with AGM-S3 or in stem cell differentiation medium; this was subsequently confirmed by the differentiation into granulocytes, macrophages, and erythroblasts in a colony-formation assay. We are now trying to produce BiPSCs in which cTr t(11;14) is induced when they differentiate into mature B cells expressing CD27. First, we used the Cre-loxP recombination system to induce cTr t(11;14) in BiPSCs. BiPSCs were transfected with IgH loxP-Neo-loxP knock-in vector and IgH lentiCRISPRv2 vector. Subsequently, G418-resistant BiPSCs carrying loxP-Neo-loxP in IgH were transfected with iCre-EGFP. After removing the loxP-Neo site from EGFP-positive cells, BiPSCs carrying IgH-loxP were transfected with CCND1 loxP-FRT3-Neo-FRT3 knock-in vector and CCND1 lentiCRISPRv2 vector. Subsequently, G418-resistant BiPSCs carrying IgH-loxP in IgH and loxP-FRT3-Neo-FRT3 in CCND1 were transfected with Flpo-EGFP. After removing the FRT3-Neo site from EGFP-positive cells, BiPSCs carrying IgH-loxP in IgH and CCND1-loxP-FRT3 in CCND1 were transfected with iCre-HygR. Hygromycin B-resistant cells were picked, the reciprocal cTr t(11;14) was confirmed by polymerase chain reaction, and we established BiPSCs with der(11)t(11;14) and BiPSCs with der(14)t(11;14). We also developed a system in which Cre is expressed along with CD27 expression in the B cell lymphoma cell line Raji. These BiPSCs could be useful for the study of myeloma-initiating cells, but whether they would be able to be redifferentiated into B lymphocyte is important. Disclosures Hanamura: Mundipharma K.K.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; CSL Behring: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD K.K.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sanofi K.K.: Research Funding; Otsuka Pharmaceutical Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; SHIONOGI Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis Pharma K.K.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; DAIICHI SANKYO COMPANY, LIMITED: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kyowa Kirin Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Eisai Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; NIPPON SHINYAKU CO.,LTD.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer Japan Inc.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie Inc.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda Pharmaceutical Company Limited: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen Pharmaceutical K.K.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Ono Pharmaceutical Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

Summary: Targeted knockin mediated by double-stranded DNA cleavage is accompanied by unwanted insertions and deletions (indels) at on-target and off-target sites. A nick-mediated approach scarcely generates indels but exhibits reduced efficiency of targeted knockin. Here, we demonstrate that tandem paired nicking, a method for targeted knockin involving two Cas9 nickases that create nicks at the homologous regions of the donor DNA and the genome in the same strand, scarcely creates indels at the edited genomic loci, while permitting the efficiency of targeted knockin largely equivalent to that of the Cas9-nuclease-based approach. Tandem paired nicking seems to accomplish targeted knockin by DNA recombination analogous to Holliday’s model and creates intended genomic changes without introducing additional nucleotide changes, such as silent mutations. Targeted knockin through tandem paired nicking neither triggers significant p53 activation nor occurs preferentially in p53-suppressed cells. These properties of tandem paired nicking demonstrate its utility in precision genome engineering. : Hyodo et al. describe a method of precise genome editing using Cas9 nickases, which barely introduces unwanted insertions and deletions at the edited genomic loci. This method neither activates nor is inhibited by p53 signalling, allowing safe genome editing and suggesting promise for this method in clinical genome engineering. Keywords: CRISPR/Cas9, nickase, tandem paired nicking, knockin, Holliday’s model, crossover, non-crossover, p53, p21, tandem nicking

Arsenic, a naturally-occurring toxic element, and a traditionally-used drug, has received a great deal of attention worldwide due to its curative anti-cancer properties in patients with acute promyelocytic leukemia. Among the arsenicals, arsenic trioxide has been most widely used as an anti-cancer drug. Recent advances in cancer therapeutics have led to a paradigm shift away from traditional cytotoxic drugs towards the targeting of proteins closely associated with driving the cancer phenotype. Due to the diverse anti-cancer effects of ATO on different types of malignancies, numerous studies have made efforts to uncover the mechanisms of ATO-induced tumor suppression. From in vitro cellular models to studies in clinical settings, ATO has been extensively studied. The outcomes of these studies have opened doors to establishing improved molecular-targeted therapies for cancer treatment. The efficacy of ATO has been augmented by combination with other drugs. In this review, we discuss recent arsenic-based cancer therapies and summarize the novel underlying molecular mechanisms of the anti-cancer effects of ATO.

Osteosarcomas (OS) are aggressive tumors that are characterized by dysregulated growth and resistance to apoptosis. Reactive oxygen species (ROS) are thought to be important signal transduction molecules in the regulation of cell growth. ROS-generating nicotinamide adenine dinucleotide phosphate oxidase (NOX) family enzymes have previously been suggested to be involved in neoplastic proliferation. To examine whether NOX-mediated generation of intracellular ROS confers anti-apoptotic activity, and thus a growth advantage, the current study first analyzed the mRNA expression of NOX family members by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in five human OS cell lines. RT-PCR analysis revealed that NOX2 and NOX4 mRNAs were expressed in all the OS cell lines examined, whereas little or no NOX1 and NOX3 mRNAs were detected. By RT-qPCR, NOX2 mRNA expression levels were demonstrated to be higher than NOX4 mRNA expression levels. The viability of OS cells decreased in a dose-dependent manner with treatment of diphenylene iodonium (DPI), an inhibitor of flavoprotein-dependent oxidase. DPI treatment was observed to reduce intracellular ROS levels by ~50%, and increase the frequency of apoptosis by 30%. Notably, small interfering RNAs (siRNAs) targeting NOX2 significantly suppressed ROS generation; ROS depletion by DPI or NOX2 siRNAs induced apoptosis in OS cells. Together, the results of the present study indicate that NOX2-mediated ROS generation promotes cell survival and ROS depletion leads to apoptosis, thus highlighting the NOX2-ROS signaling pathway as a potential therapeutic target for OS treatment.

Phosphatase and tensin homolog (PTEN) deficiency is associated with development, progression, and metastasis of various cancers. However, changes in gene expression associated with PTEN deficiency have not been fully characterized. To explore genes with altered expression in PTEN‑deficient cells, the present study generated a PTEN‑knockout cell line (ΔPTEN) from a mouse prostate cancer‑derived cell line using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR‑associated protein 9 (CRISPR/Cas9) gene editing system. Following transfection of the CRISPR/Cas9 construct, DNA sequencing was performed to identify deletion of the Pten locus and PTEN inactivation was verified by western blotting. The ΔPTEN cell line exhibited enhanced RAC‑alpha serine/threonine‑protein kinase phosphorylation and cyclin D1 expression. In addition, an increase in cell proliferation and colony formation was observed in the ΔPTEN cell line. Gene expression profiling experiments were analyzed with microarray and microRNA (miRNA) arrays. In the microarray analysis, 111 genes exhibited ≥10‑fold increased expression compared with the parent strain and mock cell line and 23 genes were downregulated. The only miRNA with increased expression of 10‑fold or more was mmu‑miR‑210‑3p. Genes with enhanced expression included genes involved in the development, progression, and metastasis of cancer such as Tet methylcytosine dioxygenase 1, twist family BHLH transcription factor 2, C‑fos‑induced growth factor and Wingless‑Type MMTV Integration Site Family, Member 3, and genes involved in immunosuppression such as Arginase 1. The results of the present study suggest that PTEN deficiency mobilizes a variety of genes critical for cancer cell survival and host immune evasion.

We investigated biaxial stress effects on the yellow 1S ortho excitons in Cu 2 O thin films recrystallized between paired MgO plates by measuring photoluminescence spectra, X-ray diffraction and polarization microscope images. On the MgO (001) surface, we found two kinds of epitaxial growth modes of the Cu 2 O thin films. In such thin films, the yellow 1S ortho exciton states split into two or three levels depending on the respective epitaxial growth modes due to the different biaxial stresses owing to the lattice mismatches between Cu 2 O and MgO. By using effective Hamiltonians including such biaxial stress effects, we estimated the strengths of the biaxial stresses from the energy splittings of the 1S ortho excitons and confirmed the two kinds of epitaxial growth modes in our Cu 2 O thin films.

Neurofibromatosis type 1 (NF1) is a genetic disorder where affected individuals develop benign or malignant nervous system tumors. To date, NF1 is caused by mutations in the NF1 tumor suppressor gene located at chromosome band 17q11.2. In this study, we aimed to characterize novel recurrent regional chromosomal imbalances and tumor-related candidate genes in NF1-associated cutaneous neurofibromas. Nine cutaneous neurofibromas from NF1 patients were screened for recurrent chromosomal imbalances using high-resolution 400K oligonucleotide array comparative genomic hybridization (aCGH). All the cases exhibited at least one sub-microscopic abnormality. Regions of recurrent chromosomal imbalances in a least one third of cases were loss of 1q13.2 (33%, FAM19A3), 1q21.1 (44%, RABGAP1L), 2q37.1 (56%, INPP5D), 3p25.1 (67%, CHCHD4), 4p15.32 (56%, FGFBP1), 5q11.2 (56%, ARL15), 6q22.31 (56%, NKAIN2), 6q22.33 (67%, ARHGAP18), 6q25.1 (67%, UST), 7q13 (56%, ADCY1), 12q13.13 (44%, KRT71), 19q13.32 (56%, GRLF1), and 20p11.21 (56%, NLP) and gain of 2p23.3 (76%, C2orf53), 8q22.3 (44%, ODF1) and 8q24.3 (67%, ARC). Several chromosomal imbalances, including loss of 7q11.23, 13q14.1, 14q32.13, 17p12, and 17q11.2 were detected at a lower frequency. We also confirmed that these chromosomal imbalances were not detected in the patient-matched lymphocyte DNAs. Amongst the 6 tumor-related candidate genes (RABGAP1L, ADCY1, SLIT2, GRLF1, UST, and ARC) identified in the regions of recurrent chromosomal imbalances, the gene expression changes of UST (down-regulation) and ARC (up-regulation) were found to be significantly associated with copy number alterations. The novel recurrent chromosomal imbalances and the altered expression levels of the tumor-related candidate genes may be associated with the development of NF1-associated benign cutaneous neurofibromas.

Versican, a large chondroitin sulfate (CS) proteoglycan, serves as a structural macromolecule of the extracellular matrix (ECM) and regulates cell behavior. We determined the function of versican in dermal development using VcanΔ3/Δ3 mutant mice expressing versican with deleted A-subdomain of the N-terminal G1 domain. The mutant versican showed a decreased hyaluronan (HA)-binding ability and failed to accumulate in the ECM. In the early developmental stage, VcanΔ3/Δ3 dermis showed a decrease in versican expression as compared with WT. As development proceeded, versican expression further decreased to a barely detectable level, and VcanΔ3/Δ3 mice died at the neonatal period (P0). At P0, VcanΔ3/Δ3 dermis exhibited an impaired ECM structure and decreased cell density. While the level of collagen deposition was similar in both genotypes, collagen biosynthesis significantly decreased in VcanΔ3/Δ3 fibroblasts as compared with that in wild type (WT). Transforming growth factor β (TGFβ) signaling mediated through the Smad2/3-dependent pathway was down-regulated in VcanΔ3/Δ3 fibroblasts and a reduced TGFβ storage in the ECM was observed. Microarray analysis revealed a decrease in the expression levels of transcription factors, early growth response (Egr) 2 and 4, which act downstream of TGFβ signaling. Thus, our results suggest that A-subdomain is necessary for adequate versican expression in dermis and that versican is involved in the formation of the ECM and regulation of TGFβ signaling.

The cellular origin of multiple myeloma (MM) has not ben identified. Based on the results of transplantation experiments using bone marrow samples from MM patients in immunodeficient mice, so-called myeloma stem cells have been inferred to be present in CD19-/CD38++/CD138+ or CD138- plasma cells populations; however, it is possible that the results indicated the presence of plasma cell populations with cell proliferation ability rather than the cellular origin of myeloma cells. On the other hand, based on immunoglobulin heavy chain (IgH) gene analysis, myeloma cells are derived from mature B cells. Chromosomal aberrations such as trisomy and chromosomal translocation play a critical role in early tumorigenesis of MM. We hypothesize that the reprograming of mature B cells, in which IgH gene rearrangements have maintained, are the origin of MM. We propose that mature B cells gain potential by reprograming, and then chromosomal aberrations cause the development of abnormal B cells as a myeloma-initiating cell during B cell redifferentiation. To identify myeloma-initiating cells, we established normal B cell-derived induced pluripotent stem cells (BiPSCs; BiPSC13 and MIB2-6). These BiPSCs maintain VDJ rearrangement of the IgH gene, and they can be induced by the tet-off system to express activation-induced cytidine deaminase (AID; BiPSC13-AID and MIB2-6-AID) and differentiate into hematopoietic progenitor cells (HPCs) (Scientific Rep, 2017). Subsequently, we used the CRISPR/Cas9 system (Oncology Letters, 2019) to establish two BiPSCs with chromosomal translocation t(11;14); the cleavage site were located in the IgH Eμ region of the VDJ non-rearranged allele of the IgH gene and the CCND1 5'-upsteam region of the CCND1 gene (BiPSC13 with t(11;14) and MIB2-6 with t(11;14)). Furthermore, p53 was deleted using the CRISPR/Cas9 system (Ota A, J Cell Sci, 2017) in BiPSC13 with t(11;14) and BiPSC13-AID with t(11;14). These BiPSCs differentiated into CD34+/CD38-/CD45+/-/CD43- HPCs in co-culture with stromal cell, AGM-S3, and their ability to subsequently differentiate into granulocytes, macrophages, and erythroblasts was confirmed by colony-formation assay. Until now, the co-culture of BiPSC13, MIB2-6, and MIB2-6 with t(11;14) with AGM-S3 followed by co-culture with stromal cell, MS-5, showed the appearance of CD34-/CD45+ and CD34-/CD10+ cell population. Also of interest, by RT-PCR, the expression levels of E2F, EBF, GATA3 and CD10 were higher in CD34+ HPCs differentiated by the co-culture of BiPSC13 and MIB2-6 with AGM-S3 when compared to the levels in cord blood-derived CD34+ cells. Overall, the results suggest that these BiPSCs have the ability to differentiate into HPCs, and that they may further differentiate into B cells. If these BiPSCs could be differentiated into mature B cells, they may be useful for the elucidation and study of myeloma-initiating cells derived from mature B cells. Disclosures Hanamura: Mundi: Honoraria; Yamada Yohojo: Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Nihon Shinyaku: Honoraria, Research Funding; Fukuyu Hospital: Research Funding; Fujimoto: Research Funding; Taiho: Research Funding; Ono: Consultancy, Honoraria, Research Funding; Otsuka: Honoraria, Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Chugai: Research Funding; Eisai: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Eli Lilly: Research Funding; Asai Clinic: Research Funding; AbbVie: Honoraria; MSD: Research Funding; Daiichi Sankyo: Consultancy, Honoraria, Research Funding; Zenyaku: Research Funding; Sanofi: Research Funding; Shionogi: Honoraria, Research Funding; Kyowa Kirin: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Astellas: Research Funding; Pfizer: Honoraria, Research Funding.

Background Surgery is often accompanied by scar formation, which results in a pathological state called fibrosis. Fibrosis is characterized by the excess deposition of extracellular matrix molecules in the connective tissue, leading to tissue contracture and chronic pain. To understand the molecular mechanisms underlying these processes and their causative relationships, we performed comprehensive analyses of gene expression changes in the hind paw tissue of a mouse model established by generating a scar in the sole. Results Subcutaneous tissue was extensively stripped from the sole of the operation group mice, while a needle was inserted in the sole of the sham group mice. Pain threshold, as evaluated by mechanical stimulation with von Frey fiber, decreased rapidly in the operated (ipsilateral) paw and a day later in the nonoperated (contralateral) paw. The reductions were maintained for more than three weeks, suggesting that chronic pain spread to the other tissues via the central nervous system. RNA from the paw and the dorsal root ganglion (L3–L5) tissues were subjected to microarray analyses one and two weeks following the operation. The expressions of a number of genes, especially those coding for extracellular matrix molecules and peripheral perceptive nerve receptors, were altered in the operation group mice paw tissues. The expression of few genes was altered in the dorsal root ganglion tissues; distinct upregulation of some nociceptive genes such as cholecystokinin B receptor was observed. Results of real-time polymerase chain reaction and immune and histochemical staining of some of the gene products confirmed the results of the microarray analysis. Conclusion Analyses using a novel mouse model revealed the extensive involvement of extracellular matrix-related genes and peripheral perceptive nerve receptor genes resulting in scar formation with chronic pain. Future bioinformatics analyses will explore the association between these relationships.

Arsenic trioxide (ATO) is one of the most potent drugs in cancer chemotherapy, and is highly effective in treating both newly diagnosed and relapse patients with acute promyelocytic leukemia (APL). Despite a number of reports regarding the molecular mechanisms by which ATO promotes anti‐tumor or pro‐apoptotic activity in hematological and other solid malignancies, the effects of ATO on immune responses remain poorly understood. To further understand and clarify the effects of ATO on immune responses, we sought to examine whether ATO affects the production of nitric oxide (NO) in a lipopolysaccharide (LPS)‐stimulated mouse macrophage cell line, RAW 264.7. Arsenic trioxide was found to prevent NO production in a dose‐dependent manner. Arsenic trioxide significantly inhibited the increase in inducible nitric oxide synthase (iNOS) at both the mRNA and protein levels. Furthermore, our analyses revealed that the inhibitory effect of ATO on iNOS expression was ascribed to the prevention of IRF3 phosphorylation, interferon (IFN)‐β expression, and STAT1 phosphorylation, but not the prevention of the MyD88‐dependent pathway. Taken together, our results indicate that ATO prevents NO production by inhibiting the TIR‐domain‐containing adaptor protein inducing IFN‐β (TRIF)‐dependent pathway, thus highlighting an anti‐inflammatory property of ATO in innate immunity.

NADPH oxidases, also known as the Nox family, are major sources of reactive oxygen species generation that regulate redox-sensitive signaling pathways. Recent studies have implicated the Nox family in cancer development and progression. However, the involvement of its members in the development of oral squamous cell carcinoma (OSCC) remains to be elucidated. To clarify this issue, we first analyzed mRNA expression of Nox/Duox family members (Nox1, Nox2, Nox3, Nox4, Nox5, Duox1 and Duox2) in five OSCC cell lines. Nox1 and Nox4 mRNAs were highly expressed in four OSCC cell lines. Western blot analysis revealed that the protein expression level of Nox1 was higher than that of Nox4 in the OSCC cell lines. In addition, knockdown of Nox1, but not Nox4, significantly suppressed cell viability and induced apoptosis in the HSC-2 and HSC-3 cells. We also found that a specific AKT inhibitor, perifosine, dose-dependently suppressed OSCC cell growth. Notably, Nox1 knockdown significantly attenuated the phosphorylation level of AKT. Furthermore, both Nox1 knockdown and perifosine treatment markedly enhanced the cisplatin-induced cytotoxic effect. Taken together, our results highlight that the Nox1/AKT signaling pathway plays an important role in cell survival in OSCC cells.

Splice variants of certain genes impact on genetic biodiversity in mammals. The tumor suppressor TP53 gene (encoding p53) plays an important role in the regulation of tumorigenesis in hepatocellular carcinoma (HCC). Δ40p53α is a naturally occurring p53 isoform that lacks the N-terminal transactivation domain, yet little is known about the role of Δ40p53α in the development of HCC. Here, we first report on the role of Δ40p53α in HCC cell lines. In the TP53+/Δ40 cell clones, clonogenic activity and cell survival dramatically decreased, whereas the percentage of senescence-associated β-galactosidase (SA-β-gal)-positive cells and p21 (also known as WAF1, CIP1 and CDKN1A) expression significantly increased. These observations were clearly attenuated in the TP53+/Δ40 cell clones after Δ40p53α knockdown. In addition, exogenous Δ40p53 expression significantly suppressed cell growth in HCC cells with wild-type TP53, and in those that were mutant or null for TP53. Notably, Δ40p53α-induced tumor suppressor activity was markedly attenuated in cells expressing the hot-spot mutant Δ40p53α-R175H, which lacks the transcription factor activity of p53. Moreover, Δ40p53α expression was associated with increased full-length p53 protein expression. These findings enhance the understanding of the molecular pathogenesis of HCC and show that Δ40p53α acts as an important tumor suppressor in HCC cells., Summary: Δ40p53 exerts tumor suppressor activity that is associated with upregulation of p53-target gene expression and induces senescence in hepatocellular carcinoma cell lines.

We previously established normal B cell-derived induced pluripotent stem cells (BiPSCs; BiPSC13 and MIB2-6). BiPSCs are known to maintain VDJ rearrangement of the IgH gene, and they can be induced by the tet-off system to express activation-induced cytidine deaminase (AID; BiPSC13-AID and MIB2-6-AID) and differentiate into hematopoietic progenitor cells (HPCs) (Scientific Rep, 2017). Using these BiPSCs, we attempted to prove the existence of abnormal B cells, which are thought to be myeloma-initiating cells, originating from mature B cells transformed by reprogramming. We speculated that BiPSCs could develop into myeloma-initiating cells that undergo chromosomal translocation or gain genetic abnormalities during redifferentiation into mature B cells. First, using the comet assay, we confirmed the DNA-damaging effect of AID in BiPSCs-AID. Secondly, we differentiated BiPSC13-AID into CD34+/CD38-/CD43-/CD45- cells by co-culture with stromal cells (mouse embryo cell line: 10T1/2), and we subsequently transplanted the cells into the bone marrow (BM) of immunodeficient NRG mice. The presence of CD34+ cells was still observed in mouse BM 4 months after transplantation; however, no differentiation into B cells was detected. Next, using the CRISPR/Cas9 system, we attempted to make BiPSCs with chromosomal translocation t(11;14); we succeeded in establishing a 293T cell line with t(11;14), then confirmed t(11;14) in MIB2-6-AID, and the clone is now being established. Furthermore, we established BiPSC13-Pax5, which can be induced by the tet-off system to express Pax5, and we then differentiated BiPSC13-Pax5 into CD34+/Pax5+/CD38-/CD43-/CD45- cells by co-culture with stromal cells (10T1/2). We expect that the HPCs or hematopoietic stem cells (HSCs) derived from BiPSCs will further differentiate into B cells due to the expression of Pax5 in the BM of NRG mouse. We also established BiPSC13-AID-p53-/-, in which p53 was deleted using the CRISPR/Cas9 system, and the cells differentiated into HPCs. Interestingly, we detected some CD43+/CD45+ cells among CD34+/CD38- cells after the co-culture of BiPSC13-AID with aorta-gonad-mesonephros-derived stromal cell (AGM-S3) instead of 10T1/2. Therefore, AGM-S3 may promote the differentiation of BiPSCs into cells that are more similar to HSCs. These CD34+ cells differentiated from BiPSCs will be transplanted into the BM of NRG mouse. Disclosures Hanamura: CHUGAI PHARMACEUTICAL CO., LTD.: Research Funding; Kyowa Hakko Kirin Company, Limited: Research Funding; Fujimoto Pharmaceutical Corporation: Research Funding; Takeda Pharmaceutical Company Limited.: Other: Lecture fee; Bristol-Myers Squibb: Other: Lecture fee, Research Funding; Celgene: Other: Lecture fee.

Objective Using a proteomic approach, we recently identified plasma CCL8 as a potential biomarker for diagnosis of graft-vs-host-disease (GVHD) in mice as well as humans. Because mass spectrometric analysis is only semi-quantitative, a quantitative method of measuring plasma CCL8 levels in mice is needed. Materials and Methods We established an enzyme-linked immunosorbent assay for the quantitative measurement of CCL8 concentrations in mouse plasma. Results Our newly established enzyme-linked immunosorbent assay revealed that the plasma CCL8 concentrations (mean ± standard error; n=12) were 1287 ± 55.7 ng/mL and 1604 ± 110.8 ng/mL on days 7 and 14 after allogeneic bone marrow transplantation (BMT), respectively, while the plasma concentrations was 316.6 ± 16.3 ng/mL on day 7 after syngeneic BMT. A Western blotting analysis also showed a difference in the plasma CCL8 levels between the allogeneic and syngeneic BMT groups, as did clinical GVHD scores. Neither lipopolysaccharide nor poly(I:C) elevated the plasma CCL8 concentrations, although a dramatic increase in interleukin-6 was detected after both treatments. Conclusion An elevated plasma CCL8 concentration may be a promising plasma marker for GVHD in mouse models.

The adeno-associated virus (AAV)-based targeting vector has been one of the tools commonly used for genome modification in human cell lines. It allows for relatively efficient gene targeting associated with 1-4-log higher ratios of homologous-to-random integration of targeting vectors (H/R ratios) than plasmid-based targeting vectors, without actively introducing DNA double-strand breaks. In this study, we sought to improve the efficiency of AAV-mediated gene targeting by introducing a 2A-based promoter-trap system into targeting constructs. We generated three distinct AAV-based targeting vectors carrying 2A for promoter trapping, each targeting a GFP-based reporter module incorporated into the genome, PIGA exon 6 or PIGA intron 5. The absolute gene targeting efficiencies and H/R ratios attained using these vectors were assessed in multiple human cell lines and compared with those attained using targeting vectors carrying internal ribosome entry site (IRES) for promoter trapping. We found that the use of 2A for promoter trapping increased absolute gene targeting efficiencies by 3.4-28-fold and H/R ratios by 2-5-fold compared to values obtained with IRES. In CRISPR-Cas9-assisted gene targeting using plasmid-based targeting vectors, the use of 2A did not enhance the H/R ratios but did upregulate the absolute gene targeting efficiencies compared to the use of IRES.

Amylase-producing myeloma exhibits refractoriness to chemotherapy and a dismal prognosis. In this study, we established a human myeloma cell line, 8226/AMY1, in which a lentivirally transfected AMY1 gene was stably expressed and explored its biological characteristics. 8226/AMY1 showed a survival advantage over mock control when treated with dexamethasone, bortezomib, and lenalidomide in vitro partly through inhibition of apoptosis induced by these reagents. In a xenograft murine model, 8226/AMY1 showed rapid tumor growth and reduced sensitivity to bortezomib compared with mock. A microarray gene expression analysis identified TCL1A, which functions as a coactivator of the cell survival kinase Akt, differentially up-regulated in 8226/AMY1. The expression of phosphorylated Akt was increased in the 8226/AMY1 cells following bortezomib treatment, but not in the mock cells. In addition, treatment with perifosine, an inhibitor of Akt phosphorylation, enhanced the anti-myeloma effect of bortezomib in the 8226/AMY1 cells. Our data suggest that amylase-producing myeloma reduced the sensitivity to bortezomib in vitro and in vivo, and the up-regulation of TCL1A may influence the drug susceptibility of 8226/AMY1 via the phosphorylation of Akt. These findings provide clues for developing treatment approaches for not only amylase-producing myeloma, but also relapsed and refractory myelomas.

Malignant pleural mesothelioma (MPM) is an aggressive tumor that is characterized by dysregulated growth and resistance to apoptosis. Reactive oxygen species (ROS)-generating NADPH oxidase (Nox) family enzymes have been suggested to be involved in neoplastic proliferation. Both the antioxidant N-acetylcysteine (NAC) and the inhibitor of flavoprotein-dependent oxidase, diphenylene iodonium (DPI), inhibited the cell viability of MPM cells in a dose-dependent manner. To examine whether Nox-mediated ROS generation confers antiapoptotic activity and thus a growth advantage to MPM cells, we analyzed the mRNA expression of Nox family members using quantitative RT-PCR in 7 MPM cell lines and a normal mesothelial cell line. Nox4 mRNA was expressed in all of the examined MPM cell lines, whereas little or no Nox2, Nox3 and Nox5 mRNA expression was detected. In 2 MPM cell lines, Nox4 mRNA expression was significantly higher than that in a normal mesothelial cell line. siRNAs targeting Nox4 suppressed ROS generation and cell viability in the MPM cell lines. In addition, DPI treatment and knockdown of Nox4 attenuated phosphorylation of AKT and ERK. Taken together, our results indicate that Nox4-mediated ROS, at least in part, transmit cell survival signals and their depletion leads to apoptosis, thus highlighting the Nox4-ROS-AKT signaling pathway as a potential therapeutic target for MPM treatment.

Accumulation of amyloid beta peptide (Abeta) in brain is a hallmark of Alzheimer's disease (AD). Inhibition of beta-site amyloid precursor protein (APP)-cleaving enzyme-1 (BACE1), the enzyme that initiates Abeta production, and other Abeta-lowering strategies are commonly tested in transgenic mice overexpressing mutant APP. However, sporadic AD cases, which represent the majority of AD patients, are free from the mutation and do not necessarily have overproduction of APP. In addition, the commonly used Swedish mutant APP alters APP cleavage. Therefore, testing Abeta-lowering strategies in transgenic mice may not be optimal. In this study, we investigated the impact of BACE1 inhibition in non-transgenic mice with physiologically relevant APP expression. Existing Abeta ELISAs are either relatively insensitive to mouse Abeta or not specific to full-length Abeta. A newly developed ELISA detected a significant reduction of full-length soluble Abeta 1-40 in mice with the BACE1 homozygous gene deletion or BACE1 inhibitor treatment, while the level of x-40 Abeta was moderately reduced due to detection of non-full-length Abeta and compensatory activation of alpha-secretase. These results confirmed the feasibility of Abeta reduction through BACE1 inhibition under physiological conditions. Studies using our new ELISA in non-transgenic mice provide more accurate evaluation of Abeta-reducing strategies than was previously feasible.

Deletions of the 3p arm have been detected in various solid tumors, but no study to date has investigated this deletion in diffuse large B-cell lymphoma (DLBCL). Recently, we demonstrated that 3p14.2 was deleted in approximately 30% of DLBCL cases by use of a genome-wide array-comparative genomic hybridization (CGH). For a more detailed examination of the genomic losses at 3p14.2, here we made use of contig BAC array for 3p14.2, and found that 12 DLBCL samples displayed losses. All of the deleted regions were located within the fragile histidine triad (FHIT) gene, and the most frequent region of loss was mapped to 0.4 Mbp of the region encompassing the introns 4 and 5 and exon 5 of the FHIT gene. Concomitant analysis of transcripts showed that the FHIT gene was aberrantly transcribed in 31% of the DLBCL samples examined and that the lost exons of the aberrant transcripts were correlated with genomic deletions. These findings indicate that (1) loss of genomic material at 3q14.2 is responsible for exon losses of the FHIT gene, and (2) genomic loss of the FHIT gene is one of the causes of the generation of aberrant transcripts.

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin’s lymphoma and exhibits aggressive and heterogeneous clinical behavior. To genetically characterize DLBCL, we established our own array-based comparative genomic hybridization and analyzed a total of 70 cases [26 CD-positive (CD5+) DLBCL and 44 CD5-negative (CD5−) DLBCL cases]. Regions of genomic aberrations observed in >20% of cases of both the CD5+ and CD5− groups were gains of 1q21-q31, 1q32, 3p25-q29, 5p13, 6p21-p25, 7p22-q31, 8q24, 11q23-q24, 12q13-q21, 16p13, 18, and X and losses of 1p36, 3p14, 6q14-q25, 6q27, 9p21, and 17p11-p13. Because CD5 expression marks a subgroup with poor prognosis, we subsequently analyzed genomic gains and losses of CD5+ DLBCL compared with those of CD5−. Although both groups showed similar genomic patterns of gains and losses, gains of 10p14-p15 and 19q13 and losses of 1q43-q44 and 8p23 were found to be characteristic of CD5+ DLBCL. By focusing on the gain of 13q21-q34 and loss of 1p34-p36, we were also able to identify prognostically distinct subgroups among CD5+ DLBCL cases. These results suggest that array-based comparative genomic hybridization analysis provides a platform of genomic aberrations of DLBCL both common and specific to clinically distinct subgroups.

The amplification at 13q31-q32 has been reported in not only hematopoietic malignancies but also in other solid tumors. We identified previously frequent amplification of chromosomal band 13q31-q32 in 70 cases of diffuse large B-cell lymphoma patients by conventional comparative genomic hybridization analysis. In an attempt to identify a candidate gene within this region, we used array comparative genomic hybridization and fluorescent in situ hybridization to map the 13q31-q32 amplicon. We then screened the 65 expressed sequence tags and Glypican 5 (GPC5) by reverse transcription-PCR and Northern blotting. As a result, we identified a novel gene, designated Chromosome 13 open reading frame 25 (C13orf25), which was overexpressed in B-cell lymphoma cell lines and diffuse large B-cell lymphoma patients with 13q31-q32 amplifications. However, GPC5, which has been reported to be a target gene for 13q31-q32 amplification, was truncated in one cell line, Rec1, possessing the amplification, and its expression in various cell lines with amplification at 13q31-q32 was not significantly different from that in other cell lines without amplification, suggesting that GPC5 is not likely to be the candidate gene. Additional analysis identified two major transcripts in the C13orf25 gene. The two transcripts A and B predicted open reading frames of 32 and 70-amino acid polypeptides, respectively. The former has been reported as bA121J7.2, which is conserved among species. Transcript-B also contained seven mature microRNAs in its untranslated region. These results suggest that the C13orf25 gene is the most likely candidate gene for the 13q31-q32 amplicon found in hematopoietic malignancies.

OBJECTIVES: Plumbagin (PL), a naturally occurring quinoid, exerts antitumoral effects in diverse types of cancer cells. However, the effect of PL on tumor cell proliferation in oral squamous cell carcinoma (OSCC) remains poorly understood. In this study, we assessed the efficacy of PL, in human OSCC cells. METHODS: The effect of PL on the cell growth and apoptosis of OSCC cell lines was evaluated using MTT and Annexin V assays, respectively. The effect of PL on mitochondrial membrane potential loss and reactive oxygen species (ROS) generation was evaluated using flow cytometry analysis. RESULTS: MTT assay showed that PL dose-dependently suppressed OSCC cell growth, with IC50 values ranging from 3.87 to 14.6 lM. Flow cytometry analysis revealed that PL treatment resulted in a significant decrease in mitochondrial membrane potential and an increase in the number of apoptotic cells. Notably, ROS generation was significantly elevated after PL treatment. Furthermore, a ROS scavenger, N-acetylcysteine (NAC), clearly suppressed the decrease in mitochondrial membrane potential, increase of caspase-3/7 activity, and apoptosis after PL treatment. CONCLUSION: This study provides the considerable evidence of the tumor-suppressive effect of PL, thereby highlighting its therapeutic potential for OSCC treatment.

There is a growing body of evidence supporting an intimate association of immune activation with the pathogenesis of cardiovascular diseases, including atherosclerosis. Uptake of oxidized low-density lipoprotein (oxLDL) through scavenging receptors promotes the formation of mature lipid-laden macrophages, which subsequently leads to exacerbation of regional inflammation and atherosclerotic plaque formation. In this study, we first examined changes in the mRNA level of the lectin-like oxLDL receptor-1 (LOX-1) in the mouse macrophage cell line RAW264.7 and the human PMA-induced macrophage cell line THP-1 after LPS stimulation. LPS significantly up-regulated LOX-1 mRNA in RAW264.7 cells; LOX-1 cell-surface protein expression was also increased. Flow cytometry and fluorescence microscopy analyses showed that cellular uptake of fluorescence (Dil)-labeled oxLDL was significantly augmented with LPS stimulation. The augmented uptake of Dil-oxLDL was almost completely abrogated by treatment with an anti-LOX-1 antibody. Of note, knockdown of Erk1/2 resulted in a significant reduction of LPS-induced LOX-1 up-regulation. Treatment with U0126, a specific inhibitor of MEK, significantly suppressed LPS-induced expression of LOX-1 at both the mRNA and protein levels. Furthermore, LOX-1 promoter activity was significantly augmented by LPS stimulation; this augmentation was prevented by U0126 treatment. Similar results were also observed in human PMA-induced THP-1 macrophages. Taken together, our results indicate that LPS up-regulates LOX-1, at least in part through activation of the Erk1/2 signaling pathway, followed by augmented cellular oxLDL uptake, thus highlighting a critical role of TLR4-mediated aberrant LOX-1 signaling in the pathogenesis of atherosclerosis.

Introduction: Primary refractory DLBCL is an extremely difficult condition to treat and represent an unmet medical need. The clarification of the molecular pathogenesis of this disease can contribute the development of new therapeutic possibilities. PVT1 is located adjacent to MYC at 8q24 and a non-protein coding gene. PVT1 produces a variety of long non-coding RNAs (lncRNAs) and has now emerged as a potential regulator in the pathogenesis of a lot of cancers. However, the precise biological and clinical significance of PVT1 remains largely unknown. In this study we established a novel human DLBCL cell line with hsr (homogeneous staining region) of 8q24 inducing high expression of PVT1 lncRNAs, named AMU-ML2. The cell line was established from a patient with primary refractory DLBCL before initiation of chemotherapy. We analyzed the genetic characteristics and investigated the drug sensitivity of the cell line in comparison with other B-cell lymphoma cell lines which had 8q24 abnormalities. Case: A 64-year-old man was diagnosed as DLBCL involved with bone marrow and pleural effusion. He was refractory to initial R-CHOP and subsequent R-hyper-CVAD/MA therapy and died of Trichosporon asahiisepsis 6 months after diagnosis. His lymphoma cells at diagnosis were positive for CD19, CD20, BCL6 and HLA-DR, and negative for CD3, CD5, CD10, cyclinD1, BCL2, MUM1, TP53 and EBER by flow cytometry and/or immunohistochemical staining, indicative of germinal center B-cell-like (GCB) DLBCL. The representative karyotype of cells was 46,XY, including add(6)(p11), add(8)(q24), hsr 8q24, add(9)(p13) and add(17)(p11.2). Establishment of the cell line: After 2 weeks of culture, the cells in pleural effusion collected before chemotherapy started to grow in suspension. The cell line was designated as AMU-ML2 after confirmation that the cells started growing again after the conventional freeze-thaw procedure. Materials and methods: B-cell lymphoma cell lines; AMU-ML2, SU-DHL-10, Raji, P3HR-1 and VAL were used in the present study. These cell lines had t(8;14)(q24;q32) or 8q24 amplification. The genomic aberration of AMU-ML2 was analyzed by cytogenetics including G-banding and FISH (fluorescence in situ hybridization) combined with array-CGH (SurePrint G3, Agilent). The TaqMan real time RT-PCR was used for measurement of expression levels of MYC and PVT1. MTT assay was used for the cell proliferation to analyze the drug sensitivities of cyclophosphamide, doxorubicin, vincristine (VCR) and prednisolone. Results: AMU-ML2 cells showed same immunophenotypic feature and karyotype as the primary sample from the patient. FISH using a MYC/IGH probe set showed no fusion signal for IGH and MYC; however, the MYC copy number was extremely increased, corresponding to hsr on chromosome 8q24. Array-CGH revealed that a 1,462 kb region, containing both the entire MYC and PVT1 genes at 8q24.21, was amplified, with greater than 20 copies present in cells (Figure 1). In addition to amplification of the MYC/PVT1 region at 8q24, 14 additional copy number alterations were detected. These included segment losses on 6p22.1-6p21.31 and 17p13 led to the LOH of human leukocyte antigen (HLA) loci and TP53, respectively (Figure 1). Using the real time RT-PCR, the expression level of the PVT1 lncRNAs were highest in AMU-ML2 among other B-cell lymphoma cell lines that we used, while the expression level of MYC in AMU-ML2 was relatively low. The proliferation rate of AMU-ML2 was significantly higher after 72-h exposure to VCR (100, 500 and 1,000 nM) compared with other cell lines (Figure 2). Discussion: AMU-ML2 was established in 2-week culture from a refractory patient before starting the chemotherapy, therefore this cell line seems to reflect the real nature of primary refractory DLBCL, not related to chemotherapy and/or cell culture. MYC amplification and the LOH of TP53 and HLA may contribute to the development of lymphoma in our case. High expression of PVT1 lncRNAs was likely to be more related with drug resistance to VCR than MYC expression, although AMU-ML2 had co-amplification of MYC and PVT1. Thus, AMU-ML2 can provide insight into the genetic and biological features and the therapeutic approaches in primary refractory DLBCL. Disclosures Ueda: Mundipharma KK: Consultancy; Kyowa Hakko Kirin: Research Funding.

Although chronic arsenic exposure is a well-known risk factor for cardiovascular diseases, including atherosclerosis, the molecular mechanism underlying arsenic-induced atherosclerosis remains obscure. Therefore, this study aimed to elucidate this molecular mechanism. We examined changes in the mRNA level of the lectin-like oxidized LDL (oxLDL) receptor (LOX-1) in a mouse aortic endothelial cell line, END-D, after sodium arsenite (SA) treatment. SA treatment significantly upregulated LOX-1 mRNA expression; this finding was also verified at the protein expression level. Flow cytometry and fluorescence microscopy analyses showed that the cellular uptake of fluorescence (Dil)-labeled oxLDL was significantly augmented with SA treatment. In addition, an anti-LOX-1 antibody completely abrogated the augmented uptake of Dil-oxLDL. We observed that SA increased the levels of the phosphorylated forms of nuclear factor of kappa light polypeptide gene enhancer in B cells (NF-κB)/p65. SA-induced upregulation of LOX-1 protein expression was clearly prevented by treatment with an antioxidant, N-acetylcysteine (NAC), or an NF-κB inhibitor, caffeic acid phenethylester (CAPE). Furthermore, SA-augmented uptake of Dil-oxLDL was also prevented by treatment with NAC or CAPE. Taken together, our results indicate that arsenic upregulates LOX-1 expression through the reactive oxygen species-mediated NF-κB signaling pathway, followed by augmented cellular oxLDL uptake, thus highlighting a critical role of the aberrant LOX-1 signaling pathway in the pathogenesis of arsenic-induced atherosclerosis.

The properties of constitutive promoters within adeno-associated viral (AAV) vectors have not yet been fully characterized. In this study, AAV vectors, in which enhanced GFP expression was directed by one of the six constitutive promoters (human β-actin, human elongation factor-1α, chicken β-actin combined with cytomegalovirus early enhancer, cytomegalovirus (CMV), simian virus 40, and herpes simplex virus thymidine kinase), were constructed and introduced into the HCT116, DLD-1, HT-1080, and MCF-10A cell lines. Quantification of GFP signals in infected cells demonstrated that the CMV promoter produced the highest GFP expression in the six promoters and maintained relatively high GFP expression for up to eight weeks after infection of HCT116, DLD-1, and HT-1080. Exogenous human CDKN2A gene expression was also introduced into DLD-1 and MCF-10A in a similar pattern by using AAV vectors bearing the human β-actin and the CMV promoters. The six constitutive promoters were subsequently placed upstream of the neomycin resistance gene within AAV vectors, and HCT116, DLD-1, and HT-1080 were infected with the resulting vectors. Of the six promoters, the CMV promoter produced the largest number of G418-resistant colonies in all three cell lines. Because AAV vectors have been frequently used as a platform to construct targeting vectors that permit gene editing in human cell lines, we lastly infected the three cell lines with AAV-based targeting vectors against the human PIGA gene in which one of the six promoters regulate the neomycin resistance gene. This assay revealed that the CMV promoter led to the lowest PIGA gene targeting efficiency in the investigated promoters. These results provide a clue to the identification of constitutive promoters suitable to express exogenous genes with AAV vectors, as well as those helpful to conduct efficient gene targeting using AAV-based targeting vectors in human cell lines.

The selective pressures leading to cancers with mutations in both KRAS and PIK3CA are unclear. Here, we show that somatic cell knockin of both KRAS G12V and oncogenic PIK3CA mutations in human breast epithelial cells results in cooperative activation of the phosphoinositide 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways in vitro, and leads to tumor formation in immunocompromised mice. Xenografts from double-knockin cells retain single copies of mutant KRAS and PIK3CA, suggesting that tumor formation does not require increased copy number of either oncogene, and these results were also observed in human colorectal cancer specimens. Mechanistically, the cooperativity between mutant KRAS and PIK3CA is mediated in part by Ras/p110α binding, as inactivating point mutations within the Ras-binding domain of PIK3CA significantly abates pathway signaling. In addition, Pdk1 activation of the downstream effector p90RSK is also increased by the combined presence of mutant KRAS and PIK3CA. These results provide new insights into mutant KRAS function and its role in carcinogenesis. Cancer Res; 73(11); 3248–61. ©2013 AACR.

Although chronic arsenic exposure is a well-known risk for cardiovascular disease and has a strong correlation with hypertension, the molecular pathogenesis underlying arsenic exposure-induced hypertension remains poorly understood. To delineate the pathogenesis, we examined changes in the mRNA levels of 2 angiotensin II Type I receptor (AT1R) subtypes, AT1AR and AT1BR, in a mouse aortic endothelial cell line, END-D. Quantitative real-time PCR analysis revealed significant increases in the mRNA levels of 2 AT1R subtypes, AT1AR and AT1BR following sodium arsenite (SA) treatment. Flow cytometry analysis revealed that SA increases the generation of reactive oxygen species (ROS) in a dose-dependent manner. In addition, western blot analysis revealed that SA enhances the phosphorylations of c-Jun N-terminal kinases (JNK) and activated protein 1 (AP-1). These phosphorylations were inhibited by N-acetylcysteine (NAC), an anti-oxidant. Finally, SA-induced AT1R expression was found to be prevented both by NAC and specific JNK inhibitor, SP6001325, strongly indicating that AT1R upregulation is a result of the ROS-mediated activation of the JNK signaling pathway. Taken together, our results indicate that arsenic indeed upregulates the AT1R expression, thus highlighting a role of arsenic-induced aberrant AT1R signaling in the pathogenesis of hypertension.

Gene targeting in most of human somatic cell lines has been labor-intensive because of low homologous recombination efficiency. The development of an experimental system that permits a facile evaluation of gene targeting efficiency in human somatic cell lines is the first step towards the improvement of this technology and its application to a broad range of cell lines. In this study, we utilized phosphatidylinositol glycan anchor biosynthesis class A (PIGA), a gene essential for the synthesis of glycosylphosphatidyl inositol (GPI) anchors, as a reporter of gene targeting events in human somatic cell lines. Targeted disruption of PIGA was quantitatively detected with FLAER, a reagent that specifically binds to GPI anchors. Using this PIGA-based reporter system, we successfully detected adeno-associated virus (AAV)-mediated gene targeting events both with and without promoter-trap enrichment of gene-targeted cell population. The PIGA-based reporter system was also capable of reproducing previous findings that an AAV-mediated gene targeting achieves a remarkably higher ratio of homologous versus random integration (H/R ratio) of targeting vectors than a plasmid-mediated gene targeting. The PIGA-based system also detected an approximately 2-fold increase in the H/R ratio achieved by a small negative selection cassette introduced at the end of the AAV-based targeting vector with a promoter-trap system. Thus, our PIGA-based system is useful for monitoring AAV-mediated gene targeting and will assist in improving gene targeting technology in human somatic cell lines.

β-actin (ACTB) is one of the genes expressed most abundantly and ubiquitously in human non-muscular tissues. Here, we investigated the long-term activity of a 550-bp-long human ACTB promoter region in human cells in comparison with other commonly used constitutive promoters. We first constructed plasmid vectors expressing enhanced green fluorescent protein (GFP) driven by one of the 5 promoters, human ACTB, human elongation factor-1α (EF1α), cytomegalovirus early enhancer/chicken β-actin (CAG), cytomegalovirus (CMV), and herpes simplex virus thymidine kinase, and transfected them into multiple human somatic cell lines. Stable transfectants were maintained for 45 days, and GFP signals from the cells were quantified by fluorescence flow cytometry. GFP signals driven by the human ACTB and the CMV promoters were also compared over time for up to 60 days following transfection. We observed robust, prolonged transcriptional activity with the human ACTB promoter that is comparable to the human EF1α and the CAG promoters and significantly more stable than the CMV promoter.

Biallelic inactivation of cancer susceptibility gene BRCA1 leads to breast and ovarian carcinogenesis. Paradoxically, BRCA1 deficiency in mice results in early embryonic lethality, and similarly, lack of BRCA1 in human cells is thought to result in cellular lethality in view of BRCA1 's essential function. To survive homozygous BRCA1 inactivation during tumorigenesis, precancerous cells must accumulate additional genetic alterations, such as p53 mutations, but this requirement for an extra genetic “hit” contradicts the two-hit theory for the accelerated carcinogenesis associated with familial cancer syndromes. Here, we show that heterozygous BRCA1 inactivation results in genomic instability in nontumorigenic human breast epithelial cells in vitro and in vivo. Using somatic cell gene targeting, we demonstrated that a heterozygous BRCA1 185delAG mutation confers impaired homology-mediated DNA repair and hypersensitivity to genotoxic stress. Heterozygous mutant BRCA1 cell clones also showed a higher degree of gene copy number loss and loss of heterozygosity in SNP array analyses. In BRCA1 heterozygous clones and nontumorigenic breast epithelial tissues from BRCA mutation carriers, FISH revealed elevated genomic instability when compared with their respective controls. Thus, BRCA1 haploinsufficiency may accelerate hereditary breast carcinogenesis by facilitating additional genetic alterations.

Background Hepatocellular carcinoma (HCC) is the most commonly occurring primary liver cancer and ranks as the fifth most frequently occurring cancer, overall, and the third leading cause of cancer deaths, worldwide. At present, effective therapeutic options available for HCC are limited; consequently, the prognosis for these patients is poor. Our aim in the present study was to identify a novel target for antibody therapy against HCC. Methodology/Principal Findings We used Western blot and flow cytometric and immunocytochemical analyses to investigate the regulation of FGFR1 expression by interferon-α/β in several human hepatic cancer cell lines. In addition, we tested the efficacy of combined treatment with anti-FGFR1 monoclonal antibody and interferon-α/β in a murine xenograft model of human HCC. We found that interferon-α/β induces expression of FGFR1 in human HCC cell lines, and that an anti-FGFR1 monoclonal antibody (mAb) targeting of the induced FGFR1 can effectively inhibit growth and survival of HCC cells in vitro and in vivo. Moreover, the combination of interferon-α, anti-FGFR1 mAb and peripheral blood mononuclear cells (PBMCs) exerted a significant antitumor effect in vitro. Conclusions Our results suggest that the combined use of an anti-FGFR1 antibody and interferon-α/β is a promising approach to the treatment of HCC.

Objective To elucidate the significance of early expression of CC-chemokine ligand motif 8 (CCL8) in mice with graft-vs.-host disease (GVHD), we investigated its induction mechanisms and correlation with overall survival rate in GVHD mice. Plasma CCL8 increases on day 5 of allogeneic transplantation, when signs of GVHD are barely detectable. Increase of allogeneic splenocytes in grafts exacerbates GVHD and leads to upregulation of plasma CCL8 on day 5. Overall survival is the gold standard in determining the severity of acute GVHD in mice, but the absence of clinical and/or pathological manifestations in the early phase make it difficult to estimate vital outcomes at this stage of allogeneic marrow transplantation. Materials and Methods After lethal irradiation, BALB/c mice received bone marrow transplantation from C57BL/6 mice. Survival rate was monitored and clinical and pathological scores of GVHD were examined. Coculture of BALB/c-derived dendritic cells and C57BL/6-derived splenocytes was performed. CCL8 was measured by immunoassay. Results The plasma CCL8 level at day 5 of transplantation was closely correlated with survival rate and clinical/pathological scores on day 14. In vitro study revealed that the BALB/c-derived dendritic cells expressed CCL8 upon stimulation of C57BL/6 CD4 + T cells by cell interactions through major histocompatibility complex class II molecules. Conclusions These investigations indicate that early and preclinical expression of CCL8 in plasma predicts overall survival of GVHD mice. Together with an involvement of allo-recognition in CCL8 expression, it suggests that CCL8 plays an important role in GVHD pathology.

We have developed a novel enzyme-linked immunosorbent assay (ELISA) system for the detection of N-ERC/mesothelin in the serum of mesothelioma patients and have begun to examine its clinical usefulness. N-ERC/mesothelin is a 31-kDa protein that forms the N-terminal fragment of the full-length 71-kDa ERC/mesothelin protein, and is physiologically secreted into the blood of mesothelioma patients where it can be detected using our sandwich ELISA containing two antibodies (rabbit polyclonal anti-ERC/mesothelin antibody-282 and mouse monoclonal antibody 7E7). Our ELISA system has thus far detected much higher serum levels of N-ERC/mesothelin in mesothelioma patients than in healthy controls or patients with other lung or pleural diseases. In conclusion, N-ERC/mesothelin is a promising candidate tumor marker for mesothelioma.

We investigated the stress effects on nP yellow excitons in Cu2O thin films recrystallized epitaxially in a sample gap between paired MgO substrates. In such samples, it is expected that a two-dimensional compressive stress acts on Cu2O because of the slightly larger lattice constant of Cu2O than of MgO. To clarify such stress effects, we measured the X-ray diffraction and nP absorption transitions of the yellow excitonic system and analyzed the strain and stress effects. Although the detected lattice strain and the energy shift of the yellow excitonic band gap are smaller than the values expected from the lattice mismatch at the heterointerface, this can be explained self-consistently by considering strain and stress relaxations in Cu2O thin films with departing from the MgO heterointerface. Consequently, we can find that shallow trapping potentials for the yellow excitons are formed in the ∼1.3-µm-thick region interfaced with the MgO substrates.