Novel and robust transplantation reveals the acquisition of polarized processes by cortical cells derived from mouse and human pluripotent stem cells.

Current stem cell technologies have enabled the induction of cortical progenitors and neurons from embryonic stem cells (ESCs) and induced pluripotent stem cells in vitro. To understand the mechanisms underlying the acquisition of apico-basal polarity and the formation of processes associated with the stemness of cortical cells generated in monolayer culture, here, we developed a novel in utero transplantation system based on the moderate dissociation of adherens junctions in neuroepithelial tissue. This method enables (1) the incorporation of remarkably higher numbers of grafted cells and (2) quantitative morphological analyses at single-cell resolution, including time-lapse recording analyses. We then grafted cortical progenitors induced from mouse ESCs into the developing brain. Importantly, we revealed that the mode of process extension depends on the extrinsic apico-basal polarity of the host epithelial tissue, as well as on the intrinsic differentiation state of the grafted cells. Further, we successfully transplanted cortical progenitors induced from human ESCs, showing that our strategy enables investigation of the neurogenesis of human neural progenitors within the developing mouse cortex. Specifically, human cortical cells exhibit multiple features of radial migration. The robust transplantation method established here could be utilized both to uncover the missing gap between neurogenesis from ESCs and the tissue environment and as an in vivo model of normal and pathological human corticogenesis.

TRAIL expression up-regulated by interferon-gamma via phosphorylation of STAT1 induces myeloma cell death.

BACKGROUND: Although the cellular and molecular biological effects of interferon (IFN)-alpha have been well-investigated, the effects of IFN-gamma are less understood. MATERIALS AND METHODS: Eleven human myeloma cell lines with various myeloma-specific chromosomal translocations and overexpression of oncogenes were cultured with 1000 U/ml of IFN-gamma. In the KMS-20 cells, which showed growth inhibition due to IFN-gamma, trail expression, status of the Janus kinase (JAK)/STAT pathway were analyzed. RESULTS: KMS-20 cells showed marked up-regulation of trail, activation of STAT1 and TRAIL hyperproduction induced by IFN-gamma. CONCLUSION: The effects of IFN-gamma on growth inhibition of KMS-20 cells were characterized by activation of the JAK/STAT signalling pathway, particularly STAT1 phosphorylation, enhanced secretion of TRAIL, and auto/paracrine usage of secreted TRAIL to induce apoptotic cell death. From these results, IFN-gamma may be considered one of the drugs to be used in future multidrug chemotherapeutic regimens for myeloma patients.

Induction of CD69 antigen expression in peripheral blood mononuclear cells on exposure to silica, but not by asbestos/chrysotile-A.

While cases of silicosis are often complicated by various autoimmune disorders, patients with asbestosis develop malignant tumors such as lung cancer and malignant mesothelioma. These differences may derive from different biological effects, particularly on immunological cells, of silica and asbestos. To find differences between silica and asbestos, the early activation antigen, CD69, on T cells was examined because dysregulated and continuous activation of T cells may promote the survival of self-recognizing T cells. After cultivation of peripheral blood mononuclear cells with or without silica or chrysotile-A, an asbestos, only silica induced CD69 expression on the lymphocytes. This induction of CD69 expression was mediated by protein kinase C activation. In addition, cell-cell contact mediated by HLA-DR was more important than soluble factors secreted from silica-phagocytosed cells such as IL-1beta, IL-6, and IL-8, even though IL-6 and IL-8 were produced during the culture of PBMCs with silica and chrysotile-A. It should be examined how these activated, CD69-expressing lymphocytes affect other immune systems as well as alter themselves in terms of cytokine production and cell-cell interaction, leading to autoimmune disorders in silicosis patients.

Effects of genetic and nutritional factors on bone mineral density in young adults.

To estimate the genetic and dietary factors influencing bone mineral density (BMD) in young adults, a total of 53 healthy volunteers (HV) (age 20.89+/-1.34), from whom informed consent was obtained, answered a questionnaire on dietary factors and had DNA from peripheral blood mononuclear cells analyzed for single nucleotide polymorphisms (SNPs) for vitamin (Vit) D receptor (VDR), estrogen receptor alpha (ERalpha), interleukin 1 receptor antagonist (IL1RA), and apolipoprotein E (ApoE) genes. Daily intakes of Vit C, fiber, soybean and related foods, and green and yellow vegetables showed a correlation with % BMD. In addition, Vit B2 as well as Vit C, and vegetables were identified as important factors for BMD by Stepwise regression analysis. Among the SNPs analyzed, the B+ type of the VDR gene tended to be associated with a lower BMD, and pp type of the ER gene digested by the PvuII enzyme in females indicated a significantly lower BMD than that in males. In addition, these SNPs were also identified by factor analysis to be associated with BMD. These results suggested that a complex array of genetic factors, such as two or more SNPs or SNPs and gender, may be important to BMD.

Effects of an HMG-CoA reductase inhibitor, simvastatin, on human myeloma cells.

To look for new candidates for agents to use in maintenance therapy for myeloma patients, the growth inhibitory effects of a 3-hydroxy-3-mehtylglutaryl coenzyme A (HMG-CoA) reductase inhibitor (statin), simvastatin, was analyzed using human myeloma cell lines. Several investigations have indicated growth reduction in certain lineages of cancer cells including one report on myeloma, and inhibitory effects of statins on GTPases and involving MAP-kinases. Most (12 out of 13) myeloma lines examined showed growth inhibition when cultured with various concentrations (1-30 microM) of simvastatin in a dose-dependent manner. Simvastatin in combination with other biological response modifiers such as ATRA or DEX had additional effects on growth. In addition, anti-oxides prevented the simvastatin-induced growth inhibition and apoptosis. Furthermore, myeloma cells treated with simvastatin clearly showed inactivation of various MAP-kinase pathways such as ERK1/2, MEK1/2, JNK, and p38. Based on these findings, statins may be suitable for clinical usage in maintenance therapy for myeloma patients.

Effects of all-trans retinoic acid (ATRA) on human myeloma cells.

All-trans retinoic acid (ATRA) is a natural oxidative metabolite of Vitamin A (retinol) and is known to be a regulator of cell proliferation differentiation, especially in various malignant cells. The cyto-differentiating action of ATRA has led to its usage in the treatment of several malignancies, particularly acute promyelocytic leukemia (APL). There have been many reports regarding the cell biological effects of ATRA on human myeloma cells and a few clinical trials. Most of these reports have revealed growth inhibition by ATRA mediated by down-regulation of the IL-6/IL-6R auto/paracrine loop, and upregulation of p21/Cip1. Here, we review previous reports and introduce experimental results obtained using various myeloma cell lines established in our laboratory.

Expression of HER family receptors and effects of anti-HER2-antibody on human myeloma cell lines.

We have recently studied expression of estrogen receptors and the growth inhibitory effects of antiestrogens on human myeloma cells. In myeloma chemotherapy, Antiestrogens in combination with other chemotherapeutic agents, may have applications in which melphalan/predonisolone still remains the standard treatment. In this study, we examined expression of HER family molecules in myeloma cells to clarify the possible usage of anti-HER2-monoclonal antibody in the treatment of myeloma. Although the mRNA levels of HER family genes analyzed by RT-PCR were significantly lower in myeloma cells than breast cancer cells, some cell lines expressed a certain amount of HER2 and HER4 proteins. In addition, an anti-HER2 monoclonal antibody, rhumAbHER2, caused significant growth inhibition in six out of eight myeloma cell lines studied and these inhibitory effects were similar to those in the breast cancer cells studied previously. The rhumAbHER2 induced up-regulation of p21 family CDK-Is (cyclin dependent kinase inhibitors) and down-regulation of VEGF genes. Moreover, combination treatment with antiestrogen had an additive growth inhibitory effect. Such analyses may provide for use of rhumAbHER2 in myeloma treatment for the future.

IL-6 is a key factor in growth inhibition of human myeloma cells induced by pravastatin, an HMG-CoA reductase inhibitor.

Although recent developments in initial chemotherapeutic regimens and stem cell transplantation have achieved improvements of initial remission for myeloma patients, relapse and recurrence are still major problems. The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) have been developed for treating hyperlipidemia. Recently, there have been several reports concerning the effects of statins on cancer cells including liver, colon, leukemia, malignant B, stomach, and breast cells. In this study, the in vitro effects of pravastatin on human myeloma cells and the factors closely related to its growth inhibitory effects were examined. Although concentrations were higher than those used clinically, 4 out of 10 myeloma lines showed growth inhibition by pravastatin. The study of factors related to the inhibition indicated IL-6 is important. Indeed, rhIL-6 abolished pravastatin-induced growth inhibition in KMS-21BM cells which did not express IL-6. Statins may be useful in maintenance therapy for myeloma after the screening of IL-6 status.

IL-10 in myeloma cells.

In addition to interleukin (IL)-6, IL-10 is considered as one of the most important cytokines regulating the proliferation and cellular characteristics of myeloma cells. It is still unclear from the clinical data how serum IL-10 levels of various stages of myeloma, are related to clinical manifestations of this disease. Several studies have reported that IL-10 affects myeloma cells by stimulating secondary signals for cell proliferation through oncostatin M (OSM) and IL-11. In experiments using human myeloma cell lines established at our laboratory, IL-10 seemed to be expressed in half of myelomas simultaneously with OSM, and to be correlated with c-maf, a transcription factor, which has been known to be overexpressed in myelomas with t(14;16)(q32;q23). In addition, IL-10 abolishes all trans retinoic acid (ATRA)-induced growth inhibition of myeloma cells. The expression and production of IL-10 in myeloma patients may be important for sub-categorization and the establishment of a case-oriented therapy.

Effect of hypoxia on human seminoma cells.

Since hypoxia has been considered to enhance metastatic potential in solid tumors via a neo-angiogenesis caused by vascular endothelial cell growth factors (VEGFs) induced by hypoxia inducible factor-1alpha (HIF-1alpha), the effects of hypoxia on human seminoma cell lines were examined in terms of growth, morphology, gene expression, protein expression and cell cycle perturbation. Growth was inhibited in long-term cultures with morphological changes to the spindle form. The gene expression of VEGF-C was markedly enhanced and the production of VEGF-A increased during hypoxia, although HIF-1alpha was not upregulated at the protein or message level. Hypoxic culture caused G1 cell cycle arrest with upregulation of the p15/ink4b and p27/Kip1 genes, whereas no increase of apoptotic cells was observed on up-regulation of the heat shock protein (HSP) 70 gene. The adhesion molecules were only slightly altered.

Interleukin 10 abolishes the growth inhibitory effects of all-trans retinoic acid on human myeloma cells.

Recently, it was disclosed that all-trans retinoic acid (ATRA) inhibits myeloma cell growth by downregulating the interleukin 6 (IL-6)/IL-6 receptor (IL-6R) auto/paracrine loop, and upregulating p21/Cip1 cyclin-dependent kinase inhibitor (CDK-I), thereby inducing apoptosis with a decrease in Bcl-2 protein expression. To elucidate and generalize the effects of ATRA on the proliferation and cellular biology of myeloma cells, 12 human myeloma cell lines established in our laboratory were utilized. Two out of the 12 lines showed enhanced growth on supplementation of ATRA and were characterized by IL-10 production, downregulation of membrane Fas and reduced upregulation of p21/Cip1 CDK-I message. These characteristics may prove important for the clinical use of ATRA and should be considered before starting ATRA therapy for myeloma.

Participation of Fas-mediated apoptotic pathway in KB, a human head and neck squamous cell carcinoma cell line, after irradiation.

In head and neck clinical oncology, recurrent cancer after initial irradiation therapy is no longer sensitive to irradiation. To explore the irradiation resistance in head and neck squamous cell carcinoma, a human cell line, KB, derived from the floor of the oral cavity was used. The participation of the Fas-mediated apoptotic pathway was suggested by the upregulation of the surface Fas molecule, the reduction of the apoptotic cell fraction after inhibition of caspase 8 which is a Fas-related initiator caspase, and the changes in Fas-related genes after irradiation. Therefore, it is suggested that disruption of the Fas-mediated apoptotic pathway participates in the acquisition of irradiation-resistance in HNSCC.

Detection of anti-topoisomerase I autoantibody in patients with silicosis.

OBJECTIVES: The aim of this study was to detect anti-topoisomerase I (anti-topo I) autoantibodies, which are known to be limited in systemic sclerosis patients, in silicosis patients with no clinical symptoms of autoimmune disease. METHODS: Serum anti-topo I autoantibodies were detected using ELISA. Differences in clinical parameters between patients with and without anti-topo I autoantibodies were analyzed. RESULTS: Seven of 69 patients had anti-topo I autoantibodies. These 7 patients showed elevated PaCO(2) values (P=0.0212), and inverse correlations between serum soluble Fas levels and PaCO(2) values were found. CONCLUSION: Anti-topo I autoantibodies were detected in 10.1% of silicosis patients without any clinical symptoms of autoimmune disease. The findings here suggest that the genesis of anti-topo I autoantibodies might be related to pulmonary involvement or lung fibrosis associated with progression of silicosis.

Perturbation of secretory Ig A in saliva and its daily variation by academic stress.

OBJECTIVES: Several studies have reported that the secretory immunoglobulin A (S-IgA) concentration in saliva is an indicator of psychological stress. The aim of this study was to clarify the relationship between S-IgA and the stress from academic examinations. METHODS: S-IgA levels in 10 medical student volunteers from the second year course between May 4 and July 13, 2000 were examined using the ELISA method. RESULTS: There was a tendency for S-IgA in saliva to be higher on the day before academic examinations and during them, and lower on the days between these examinations. CONCLUSIONS: It may be possible to use this measurement to monitor psychological stress in students and workers.