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Summary Objective To investigate the mechanism of mechanical stress-induced expression and regulation of aggrecanases and examine the role of runt-related transcription factor 2 (RUNX-2) in chondrocyte-like cells. Methods SW1353 cells were seeded onto stretch chambers at a concentration of 5×10 4 cells/chamber, and a uni-axial cyclic tensile strain (CTS) (0.5Hz, 10% stretch) was applied for 30min. Total RNA was extracted, reverse transcribed, and analyzed by polymerase chain reaction (PCR) and real-time PCR. RUNX-2 overexpression and small interfering RNA (siRNA) targeting RUNX-2 were used to investigate the role of RUNX-2 in CTS-induced gene expression. The involvement of diverse mitogen-activated protein kinase (MAPK) pathways in the activation of RUNX-2, MMP-13 and ADAMTS-5 during CTS was examined by Western blotting. Results CTS induced expression of RUNX-2 , MMP-13 , ADAMTS-4 , -5 , and -9 . Overexpression of RUNX-2 up-regulated expression of MMP-13 and ADAMTS-5 , whereas RUNX-2 siRNA resulted in significant down-regulation of mechanically-induced MMP-13 and ADAMTS-5 expression. CTS induced activation of p38 MAPK, and CTS induction of RUNX-2 , MMP-13 and ADAMTS-5 mRNA was down-regulated by the selective p38 MAPK inhibitor SB203580 but not by the p44/42 MAPK inhibitor U0126, or the JNK MAPK inhibitor JNK inhibitor II. Conclusions RUNX-2 might have a role as a key downstream mediator of p38's ability to regulate mechanical stress-induced MMP-13 and ADAMTS-5 expression.

We measured the relative expression levels of galectin-3 mRNA to beta-actin mRNA in normal thyroid tissues, thyroid tumor tissues and thyroid-derived fibroblasts. Galectin-3 mRNA was expressed ubiquitously in both benign and malignant thyroid tumors. Although a significant increase in its expression was observed in papillary carcinomas, no significant difference was observed between follicular carcinomas and adenomas. In contrast to the previous optimistic reports using immunohistochemical analysis of the galectin-3 protein expression, these results demonstrate that galectin-3 mRNA may not be a suitable target for molecular-based diagnosis of thyroid carcinomas.

Two distinct human light subunits of the heteromeric amino acid transporter, y+LAT-1 coded by SLC7A7 and y+LAT-2 coded by SLC7A6, are both known to induce transport system y+L activity. SLC7A7 has already been identified as the gene responsible for lysinuric protein intolerance (LPI). We successfully identified five novel SLC7A7 variants (S238F, S489P, 1630delC, 1673delG, and IVS3-IVS5del9.7kb) in Japanese patients with LPI by PCR amplification and direct DNA sequencing. In addition, we performed a semi-quantitative expression analysis of SLC7A7 and SLC7A6 in human tissue. In normal tissue, the gene-expression ratio of SLC7A6 to SLC7A7 was high in the brain, muscle, and cultured skin fibroblasts; low in the kidneys and small intestine; and at an intermediate level in peripheral blood leukocytes, the lungs, and cultured lymphoblasts. The gene-expression ratio of SLC7A6 to SLC7A7 in cultured lymphoblasts was significantly different between normal subjects and LPI patients with R410X and/or S238F, where the relative amount of SLC7A7 mRNA was significantly lower and the relative amount of SLC7A6 mRNA was statistically higher in affected lymphoblasts than in normal cells. Expression of SLC7A7 and SLC7A6 may thus be interrelated in cultured lymphoblasts. Hum Mutat 20:375–381, 2002. © 2002 Wiley-Liss, Inc.

Yoshida T, Hayashi M, Monkawa T, Saruta T. Regulation of obese mRNA expression by hormonal factors in primary cultures of rat adipocytes. Eur J Endocrinol 1996;135:619–25. ISSN 0804–4643 The obese (ob) gene has been cloned recently and its protein product is called "leptin". Leptin is an adipocyte-derived satiety factor that regulates body weight homeostasis. Several hormonal factors have been reported to regulate ob mRNA expression. To determine which factors are most important for regulation of ob mRNA expression, we examined the effects of insulin, dexamethasone, a β3-adrenergic agonist (CGP12177A), 8-bromo-cAMP, 8-bromo-cGMP and 1-methyl-3-isobutylxanthine (MIX) on primary cultured adipocytes. Rat adipocytes obtained from epididymal fat were cultured using the ceiling method. Total RNA was extracted and the expression of ob mRNA was measured by quantitative reverse transcription-polymerase chain reaction. After 24 h of incubation, 100 nmol/l insulin significantly increased the expression of ob mRNA (21.4-fold compared to control). Moreover, insulin increased ob mRNA expression in a dose-dependent manner over a range of 1–100 nmol/l. The effect of 100 nmol/l insulin was similar to that seen with 20% newborn calf serum. Dexamethasone (25–1000 nmol/l) also increased ob mRNA expression (2.5–2.9-fold). The effect of dexamethasone occurred more rapidly than insulin. CGP12177A (1–10 μmol/l) and 0.5 mmol/l 8-bromo-cAMP had no effects, whereas 0.5 mmol/l 8-bromo-cGMP and 0.5 mmol/l MIX had stimulatory effects (2.8- and 2.4-fold increase in ob mRNA, respectively). The combination of 250 nmol/l dexamethasone and 0.5 mmol/l MIX did not have an additive effect on ob mRNA levels. Our present data suggest that, of these agents, insulin is the most important factor regulating ob mRNA expression. Matsuhiko Hayashi, Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160, Japan

Cyclic ADP-ribose (cADPR), a well-known stimulator of ca(2+) release from the intracellular Ca(2+) pool, has recently emerged as a potential regulator of insulin secretion in pancreatic beta cells. As recently described, BST-1 is a glycosyl-phosphatidylinositol (GPI)-anchored surface molecule that exhibits homology with CD38 and Aplysia ADP-ribosyl cyclase. Like CD38, BST-1 has both ADP-ribosyl cyclase and cADPR hydrolase activities. As a step toward elucidating the physiological role of cADPR in insulin secretion we examined whether BST-1 is expressed in pancreatic islet cells. Sensitive reverse transcription-polymerase chain reaction detected almost as abundant expression of BST-1 mRNA in pancreatic islets as CD38 mRNA. Immunohistochemical analyses utilizing mirror image sections revealed that BST-1 protein is expressed in a majority of the cells in pancreatic islets and that at least beta cells and, to an even greater extent, alpha cells express BST-1. These observations suggest the involvement of multiple enzymes in the regulation of cADPR concentrations in pancreatic islet cells.

Using subcutaneous solid tumors produced by U251-MG human glioma cells, we studied the in vivo transfection of the cells with the tumor necrosis factor-alpha (TNF-alpha) gene delivered by means of liposomes. When the tumor had become 7 mm in diameter, liposomes with entrapped TNF-alpha gene were injected into the center of the subcutaneous tumor. We found that mRNA of transfection-induced TNF-alpha, which was expressed in the tumor tissue, was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) method and its protein was demonstrated by enzyme-linked immunoassay. Growth of the tumor was inhibited when the injection was carried out five times at every other day. The growth-inhibitory effect by transfection-induced TNF-alpha was much remarkable as compared with exogenous TNF-alpha and the effect was enhanced by the intraperitoneal injection of gamma-interferon (IFN-gamma) 12 h prior to intratumoral injection of the liposomes.

Erdheim-Chester disease (ECD) is a form of non-Langerhans histiocytosis. In this report, we show a case of ECD presenting diabetes insipidus and multiple xanthogranulomas received glucocorticoid treatment over a year. During this period, xanthogranulomas improved in response to the glucocorticoid therapy. Furthermore, the expression of osteopontin in xanthogranulomatous tissues significantly decreased following the treatment. Our data show the expression of osteopontin in xanthogranulomatous tissues of ECD. Furthermore, the osteopontin mRNA decreased following glucocorticoid therapy with xanthogranuloma regression, suggesting that the expression level of osteopontin could be a marker of the disease activity of ECD.

Quantitative and qualitative analyses of mRNAs from a small number of cells are extremely important for studies on gene expression in various physiological and pathological conditions in multicellular organisms. We present here an effective method for high-fidelity global mRNA amplification for in vivo gene expression profiling of as few as 100 cells obtained by laser-captured microdissection (LCM). This method, called TALPAT, is based on T7 RNA polymerase-mediated transcription, adaptor ligation, and PCR amplification followed by T7-transcription. More than 80% of genes were commonly identified as a more than 3-fold changed gene among three gastric cancer cell lines using cRNA amplified by both TALPAT and the ordinary in vitro T7-transcription. The reproducibility of TALPAT was validated by microarray analysis on 100 breast cancer cells obtained by LCM. For the application of the LCM-TALPAT method, we successfully obtained expression profiles of gastric cancer cells and the mesenchymal cells, enabling us to understand in vivo cell-to-cell cross-talk in the microenvironment.

Reverse transcription polymerase chain reaction (RT-PCR) was performed to evaluate the sequential alteration of proto-oncogene mRNA expression in liver, spleen, kidney and brain of mice after whole body irradiation (WBI). The mRNAs investigated in this study were Fas, c-fos, c-myc. bcl-2, and p53, and glyceraldehyde-3-phosphate dehydrogenase mRNA was employed as internal control. C3H/He mice aged 9-10 weeks were exposed to WBI of 7 Gy using a cobalt-60 teletherapy unit, without anesthesia, and sacrificed before and 0.1, 0.5, 1, 2, 3, 6, 12, 24, 48 and 96 h after irradiation. Their liver, spleen, kidney and brain were taken and immediately stored in liquid nitrogen until ready for RT-PCR. Each specimen was homogenized to extract RNA for conventional RT-PCR. The liver of mice administered 7 Gy of WBI revealed no significant changes in the expression of each of the mRNAs examined. In the spleen, c-fos mRNA expression decreased at 2 h following irradiation, and increased remarkably thereafter. In the kidney, no significant change in the expression of each mRNA was shown. In the brain c-fos mRNA expression decreased 1-24 h after irradiation, and showed a recovery thereafter. The remarkable differences in the sequential changes of c-fos mRNA expression following irradiation between each organ revealed by the present experiment may be an important aid in determining the tissue-specific radiosensitivity to ionizing radiation. Further investigations are, however, needed to clarify the signal transduction mechanisms which are mediated by the expression of these proto-oncogenes in each tissue following irradiation.

Objective To characterize the multidrug resistance (MDR) phenotype in human urothelial cancers, the expression levels of four MDR-related genes (multidrug resistance, mdrl; multidrug resistance-associated protein, MRP; glutathione S-transferase-π, GST-π; and DNA topoisomerase II, topo II) were analysed in urothelial cancers. Materials and methods Fifty-two tumour tissue and three normal urothelial mucosa samples were obtained from 44 patients with urothelial cancers. The expression of each gene was analysed with a reverse-transcription polymerase chain reaction (RT-PCR) method using β2-microglobulin (b2m) mRNA as an endogenous control. Levels of expression were expressed as the ratio of the specific products of the target gene to those specific to b2m. Results In primary urothelial cancer tissues, the mean (sd) expression of mdrl, MRP, GST-πand topo II relative to b2m expression were 0.067 (0.061), 0.27 (0.23), 0.35 (0.31) and 0.12 (0.05), respectively. The mean expressions of MRP and GST-πwere higher than those of mdrl and topo II. The mean ratios of mdrl/b2m, MRP/b2m, GST-π/b2m and topo II/b2m in normal urothelial mucosa were 0.06 (0.03), 0.12 (0.09), 0.30 (0.32) and 0.14 (0.01), respectively. There was no significant association of the expression of each gene with either the grade or extent of the primary tumour. The level of MRP expression in each sample was correlated significantly with the expression of mdrl and GST-πin the urothelial cancers (r=0.637 and 0.537, respectively). Chemotherapy did not markedly influence the induction of expression of the MDR-related genes, except for one case in which mdrl expression was 15 times greater than before chemotherapy. The expression of GST-πin the patients not receiving chemotherapy was significantly higher than in those that did. Conclusions These results suggest that the activation of MRP and GST-πexpression occurs during the tumorigenesis of urothelial cancers and that it may confer de novo and acquired drug resistance on urothelial cancers. These results should provide further insight into the complex role postulated for MDR-related genes in chemotherapy, carcinogenesis and tumour progression.

A novel murine cDNA which encodes a protein designated neuropsin was cloned. Northern and in situ hybridization analyses demonstrated that neuropsin mRNA is expressed specifically in the limbic system of mouse brain and is localized at highest concentration in pyramidal neurons of the hippocampal CA1–3 subfields. Direct hippocampal stimulation and kindling induced by amygdaloid stimulation caused a significant bilateral change in neuropsin mRNA level in the hippocampal pyramidal neurons. The activity-dependent changes and the specific localization indicate that neuropsin is involved in hippocampal plasticity.

We cloned the rat Gadd45 (growth arrest and DNA damage inducible) cDNA and examined its mRNA induction by y-ray irradiation in the rat brain. The rat Gadd45 cDNA sequence was highly homologous to the previously published human and hamster cDNAs, and was partially similar to the 28S rRNA gene. The mRNA encoding rat GADD45 was induced in the brain after γ-ray irradiation. This finding indicates that Gadd45 is an inducible gene following the ionizing radiation, not only in cultured cells in vitro, but also in animal tissues in vivo.