Identification of a novel gene, MASL1, within an amplicon at 8p23.1 detected in malignant fibrous histiocytomas by comparative genomic hybridization

We used comparative genomic hybridization to study malignant fibrous histiocytomas (MFHs) from 19 patients to detect changes in the copy number of DNA sequences, along entire chromosomes. Together with losses and gains in various chromosomal regions, distinct high-level amplifications were found at six loci (4q12-21, 8p21-pter, 8q24.1-qter, 9q12-13, 12p11.2-pter, and 15q11.2-15), suggesting that those regions may contain unknown (proto) oncogenes. We focused on the 8p amplicon, where detailed characterization allowed us to determine that the minimal common amplified region lay between markers D8S1819 and D8S550 at 8p23.1. A novel gene designated MASL1 (MFH-amplified sequences with leucine-rich tandem repeats 1) was isolated from within this narrowly defined region. Expression of the MASL1 gene was enhanced significantly in MFH tumors bearing the 8p amplicon. The primary structure of its deduced product revealed an ATP/GTP-binding site, three leucine zipper domains, and a leucine-rich tandem repeat, all of which are important structural or functional elements for interactions among proteins related to the cell cycle. These features suggest that overexpression of MASL1 might well be oncogenic with respect to MFH.     

Cyclooxygenase inhibitors enhance the production of tissue inhibitor-1 of metalloproteinases (TIMP-1) and pro-matrix metalloproteinase 1 (proMMP-1) in human rheumatoid synovial fibroblasts

OBJECTIVE AND DESIGN: We investigated the influence of cyclooxygenase inhibitors against the production of tissue inhibitor-1 of metalloproteinases (TIMP-1) and pro-matrix metalloproteinase 1 (proMMP-1) in rheumatoid arthritis (RA) synoviocytes. MATERIAL: Synovial fibroblasts from RA patients were used. TREATMENT: The cells were treated with recombinant human interleukin 1 beta (rhIL-1 beta) (100 ng/ml) and/or indomethacin (0.1, 1, 10 microM) and diclofenac (0.1, 1, 10 microM) and/or prostaglandin E2 (PGE2) (1, 10 microM) for 72 h. METHODS: The amounts of TIMP-1, proMMP-1 and PGE2 was measured by enzyme linked immunosorbent assay (ELISA). Statistical significance was tested with Student's t-test and Dunnett test. RESULTS: RhIL-1 beta augments the production of TIMP-1 and proMMP-1 in synovial fibroblasts from RA patients, and this IL-1-induced production of TIMP-1 and proMMP-1 was further enhanced by treatment with the cyclooxygenase inhibitors, indomethacin and diclofenac. Exogenous PGE2 significantly suppresses indomethacin- and diclofenacenhanced TIMP-1 and proMMP-1 production. CONCLUSION: PGE2 down-regulates the production of TIMP-1 and proMMP-1 in RA synoviocytes, and cyclooxygenase inhibitors regulate the production of TIMP-1 and proMMP-1 through the inhibition of PGE2 production in inflammation.     

Detection of synaptophysin-producing cells in human thymus by immunohistochemistry and nonradioactive in situ hybridization

Hemoglobin A2 (Hb A2) and hemoglobin F (Hb F) are important analytes in the diagnosis and follow up of Hb diseases. We evaluated a new capillary zone electrophoresis (CZE) kit for Hb A2 and Hb F measurements. The imprecision ranged from 3% to 6% for Hb A2 and Hb F at physiological and pathological concentrations. The method compared well with cation-exchange HPLC for Hb A2 and Hb F and with anion-exchange chromatography in microcolumns (MAEC), for Hb A2. Nevertheless, higher results were obtained [Hb A2 CZE (%) = 1.233 Hb A2 HPLC - 0.2; Hb A2 CZE (%) = 1.190 Hb A2 MAEC + 0.1; Hb FCZE (%) = 1.118 Hb FHPLC + 0.4], and new reference values had to be determined (Hb A2 2.7-3.8%; Hb F <1.2%). Quantification of Hb A2 was not influenced by Hb S. Measurement of Hb F was accurate and precise except at low concentrations in Hb AS patients. This new CZE kit is rapid, precise, and reliable, and seems appropriate for use in clinical laboratories.     

Expression of very low density lipoprotein receptor in the vascular wall. Analysis of human tissues by in situ hybridization and immunohistochemistry

The recently cloned very low density lipoprotein (VLDL) receptor binds triglyceride-rich, apolipoprotein-E-containing lipoproteins with high affinity. The observation that VLDL receptor mRNA is abundantly expressed in extracts of tissues such as skeletal muscle and heart, but not liver, has led to the hypothesis that this receptor may facilitate the peripheral uptake of triglyceride-rich lipoproteins. However, little information is available concerning the types of cells that express this receptor in vivo. As expression of the VLDL receptor in the vascular wall might have important implications for the uptake and transport of triglyceride-rich lipoproteins, and perhaps facilitate the development of atherosclerosis in hypertriglyceridemic individuals, we used in situ hybridization and immunohistochemistry to determine whether VLDL receptor mRNA and protein was expressed in human vascular tissue. We observed expression of the receptor by both endothelial and smooth muscle cells within normal arteries and veins, as well as within atherosclerotic plaques. In the latter, the VLDL receptor was also expressed by macrophage-derived foam cells. The widespread distribution of the VLDL receptor in vascular tissue suggests a potentially important role for this receptor in normal and pathophysiological vascular processes.     

Opioid regulation of gonadotropin-releasing hormone gene expression in the male rat brain as studied by in situ hybridization

It is well documented that gonadotropin-releasing hormone (GnRH) release is negatively regulated by opiates. In order to investigate the role of opiates in the regulation of GnRH gene expression in the rat brain, we studied the effects of chronic administration of the opioid drug morphine and an opiate receptor antagonist naloxone on GnRH mRNA levels as measured by in situ hybridization. Four-day treatment with morphine (40 mg kg day-2) produced a 44% decrease in the number of silver grains overlying GnRH neurones. Conversely, naloxone (4 mg kg day-2) also administered during 4 days increased by hybridization signal by 22%. The concomitant administration of morphine and naloxone completely prevented the effect of morphine on GnRH gene expression indicating the inhibitory influence of morphine is likely to be mediated by opioid receptors. The present data clearly indicate that opiates can inhibit not only the release of GnRH and consequently LH secretion but also the biosynthesis of the neuropeptide as evaluated by mRNA level measurements.     

Analysis of immunoglobulin-synthesizing cells in human dental periapical lesions by in situ hybridization and immunohistochemistry

The iron status of 22 children and adolescents with Crohn's disease (mean age: 13 years) was evaluated. Eleven patients were suffering from active disease with inflammation, identified by at least one abnormal value for serum orosomucoid, C-reactive protein or sedimentation rate (group I). Eleven patients were in clinical remission and showed no biological evidence of inflammation (group II). Hemoglobin and red cell indices, erythrocyte protoporphyrin, serum iron, transferrin, serum ferritin and basic red cell ferritin were determined in all patients. The usual indicators of iron status, particularly serum ferritin, were affected by the inflammatory processes, but basic red cell ferritin appeared to be independent of inflammation. Basic red cell ferritin can therefore be considered to be a reliable indicator of iron status in children and adolescents with Crohn's disease.     

Differential expression of the metabotropic glutamate receptor mGluR1alpha by neurons and axons in the cochlear nucleus: in situ hybridization and immunohistochemistry

mGluR1alpha is a metabotropic glutamate receptor involved in synaptic modifiability. A differential expression in specific neuronal types could reflect their different connections and response properties in central auditory processing. Using in situ hybridization and immunohistochemistry, we studied mGluR1alpha receptor expression throughout the cochlear nucleus. Robust labeling occurred in the dorsal cochlear nucleus and small cell shell, with less in the ventral cochlear nucleus. Among the most intensely labeled were the granule cells of the small cell shell. In the dorsal cochlear nucleus, most cell types expressed message and receptor protein, except granule cells. High levels of receptor were expressed by corn cells and cartwheel cells. The terminal dendrites and synaptic spines of cartwheel and fusiform cells contained receptor protein in the molecular layer, where they could synapse with parallel fibers. Fusiform dendrites also expressed mRNA for mGluR1alpha. The basal dendrites of fusiform cells contained receptor protein in the region where they receive cochlear nerve synapses. Immunostaining of terminal axons was prominent in the molecular layer and the small cell shell, where they were associated with synaptic nests, structures thought to provide long-term changes in excitability. Differential expression levels may reflect different functional requirements of specific cell types, including inhibitory interneurons, like corn cells and cartwheel cells, and excitatory interneurons, like granule cells in the small cell shell, which may participate in local circuits involved in modulatory or gating functions, such as stimulus enhancement or suppression. In presynaptic axons, mGluR1alpha may relate to the long-term signaling requirements of their modulatory functions.     

Role of lipopolysaccharide in colonization of the mouse intestine by Salmonella typhimurium studied by in situ hybridization

An avirulent, streptomycin-resistant Salmonella typhimurium strain, SL5319, and its lipopolysaccharide (LPS)-deficient mutant strain, SL5325, differ in their ability to colonize the large intestines of streptomycin-treated mice. When fed to mice independently, the strains colonize equally well, but when fed together, the LPS-deficient mutant is outcompeted by the wild-type strain during establishment in the gut (J.J. Nevola, B.A.D. Stocker, D.C. Laux, and P.S. Cohen, Infect. Immun. 50:152-159, 1985). In the present study, the spatial distribution in the intestinal mucosal layer of the two strains was visualized by specific hybridization to bacterial rRNA in histological sections of mouse colon and cecum. The first day after infection, 9.8% of the smooth SL5319 cells observed in mucus were found to be associated with the mouse epithelial cells, but three days after infection, the corresponding fraction of adhering bacteria was reduced to 2.1%. The LPS-deficient S. typhimurium strain was confined to the part of the mucosal layer closest to the colonic lumen and was not observed to adhere to the epithelium either at day 1 or 3 after infection. Quantitative determinations of the distance from the S. typhimurium cells to the epithelial wall confirmed that the average distance for the rough S. typhimurium SL5325 was much larger than for its smooth counterpart, S. typhimurium SL5319. Quantification of the hybridization signal from bacteria isolated from the cecal mucus revealed that the two strains had the same ribosome concentration, indicating that they have the same potential for growth in the intestinal environment. On the basis of these observations, we suggest that the better colonization ability of the strain carrying wild-type LPS is due to the better abilities to penetrate the intestinal mucosal layer and to subsequently bind to the epithelial cells in vivo.     

Kinetic analysis of the binding of human matrix metalloproteinase-2 and -9 to tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2

The dissociation constants (Kd) of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 for the active and latent forms of matrix metalloproteinase (MMP)-2 and MMP-9 were evaluated using surface plasmon resonance (SPR) and enzyme inhibition studies. SPR analysis shows biphasic kinetics with high (nM) and low (microM) affinity binding sites of TIMP-2 and TIMP-1 for MMP-2 (72- and 62-kDa species) and MMP-9 (92- and 82-kDa species), respectively. In contrast, binding data of TIMP-2 to an MMP-2 45-kDa active form lacking the C-terminal domain and to an MMP-2 C-terminal domain (CTD) fragment displays monophasic kinetics with Kd values of 315 and 60 nM, respectively. This suggests that the CTD contains the high affinity binding site, whereas the catalytic domain contains the low affinity site. Also, binding of TIMP-2 to pro-MMP-2 is stronger at both the high and low affinity sites than the corresponding binding of TIMP-2 to the MMP-2 62-kDa form demonstrating the importance of the N-terminal prodomain. In addition, the Kd value of TIMP-1 for the MMP-2 62-kDa species is 28. 6 nM at the high affinity site, yet neither the MMP-2 45-kDa species nor the CTD interacts with TIMP-1. Enzyme inhibition studies demonstrate that TIMPs are slow binding inhibitors with monophasic inhibition kinetics. This suggests that a single binding event results in enzyme inhibition. The kinetic parameters for the onset of inhibition are fast (kon approximately 10(5) M-1 s-1) with slow off rates (koff approximately 10(-3) s-1). The inhibition constants (Ki) are in the 10(-7)-10(-9) M range and correlate with the values determined by SPR.     

A juxtaglomerular cell tumor. Analysis of immunohistochemistry, electron microscopy and in situ hybridization

We investigated the prognosis of completely resected 119 non-small cell lung cancer patients according to the invaded organs. There was no significant difference in prognosis between T3N0M0 and T3N1M0 patients (5-year survival rate: 34% vs. 38%). However, the prognosis of T3N2M0 patients (5-year survival rate: 11%) was too poor to be regarded as the same category. Therefore, we investigated only T3N0M0 and T3N1M0 patients to assess the contribution of the invaded organs to prognosis. Of the 5 patients with diaphragm invasion, there was no 3-year survivor, and the prognosis of patients with diaphragm invasion was very poor. The chest wall invasion was divided into three parts: parietal pleural invasion, subpleural tissue invasion and intercostal muscular invasion. The 5-year survival rates of patients with such invasion was 35%, 29% and 27%, respectively. The patients with Pancoast tumor had very poor prognosis. T3 factor was heterogeneous, and the prognosis of the patients with T3 tumor was various according to invaded organs.     

High levels of messenger RNAs for tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) in primary breast carcinomas are associated with development of distant metastases

Tissue inhibitors of metalloproteinases (TIMPs) are believed to possess several cellular functions, particularly the contrasting activities of inhibiting tissue-degrading enzymes and promoting cellular growth. In attempts to elucidate which of these functions may prevail in breast cancer, expression of mRNAs for TIMP-1 and TIMP-2 in the primary carcinomas from 34 breast cancer patients was related to known prognostic parameters and the clinical outcome. High levels of TIMP-1 mRNA showed significant correlation with the presence of lymph node metastases (P = 0.0067), development of distant metastases (P = 0.014), and early death of the disease (P = 0.020). Elevated expression of TIMP-2 mRNA was associated with development of distant metastases (P = 0.0055). No correlations, however, were observed between mRNA levels of TIMPs and prognostic factors such as patient age, tumor size, grade of anaplasia, or steroid receptor status; neither were any correlations found between these clinicopathological characteristics and the mRNA expression of the collagenolytic enzymes matrix metalloproteinase-2 and matrix metalloproteinase-9. The present data suggest that high levels of TIMP-1 and TIMP-2 mRNAs in the primary carcinomas are strongly associated with development of metastasis in breast cancer.     

A patient with myelodysplastic syndrome studied by GTG-banding and fluorescent in situ hybridization (FISH)

Molecular cytogenetics using fluorescent in situ hybridization (FISH) is an extremely useful adjunct technique to conventional cytogenetics via GTG-banding. The present paper illustrates the utility of FISH by describing a patient with myelodysplastic syndrome (MDS) who was initially studied using GTG-banding and whose bone marrow was found to be populated with hyperdiploid cells. FISH was used to delineate the numerical and structural chromosomal abnormalities. It revealed the presence of trisomy 8 and determined that the previously unidentifiable marker chromosome was of chromosome 10 origin. Although trisomy 8 is a frequent finding in MDS, the structural chromosomal abnormality of chromosome 10 as reported here is not a common finding.     

The detection of human papillomavirus in papillomas of the larynx and tonsils through immunohistochemistry and DNA in situ hybridization]

Presenting a study about Human Papillomavirus (HPV) determination by immunohistochemistry and "in situ" hybridization, in 25 samples of squamous cell papillomata (15 tonsilar and 10 laryngeal lesions). Five cases resulted positive for HPV: 2 of them for immunohistochemical probes, other 2 for "in situ" hybridization and only 1 cas showed its positivity for both techniques. All these samples belonging to laryngeal cases. No significant differences were found in antecedents, clinical and histological features related with results obtained. Two patients developed a laryngeal carcinoma after papilloma and they had positive "in situ" hybridization. Literature about diagnosis of HPV-infection was revised.     

Expression of osteopontin in Meckel's cartilage cells during phenotypic transdifferentiation in vitro, as detected by in situ hybridization and immunocytochemical analysis

The localization of osteopontin (OP) was examined in Meckel's cartilage cells that bipotentially expressed cartilage and bone phenotypes during cellular transformation in vitro. Cultured cells were analyzed by in situ hybridization, immunostaining followed by light and electron microscopy, electron microscopy, and electron probe microanalysis. The combination of ultrastructural analysis and immunoperoxidase staining indicated that OP-synthesizing cells were cells that were autonomously undergoing a change from chondrocytes to bone-forming cells at the top of nodules. Double immunofluorescence staining of 2-week-old cultures revealed that OP was first synthesized by chondrocytic cells at the top of nodules. After further time in culture, the distribution of OP expanded from the central toward the peripheral regions of the nodules. Electron probe microanalysis revealed that the localization of OP was associated with matrices of calcified cartilage and osteoid nodules that contained calcium and phosphorus. Immunoperoxidase electron microscopy revealed that, in addition to the intracellular immunoreactivity in chondrocytes and small round cells that were undergoing transformation, matrix foci of calcospherites and matrix vesicles, in particular, included growing crystals that were immunopositive for OP. An intense signal due to mRNA for OP in 3-week-old cultures was detected in nodule-forming round cells, while fibroblastic cells, spreading in a monolayer over the periphery of nodules, were only weakly labeled. These findings indicate that OP might be expressed sequentially by chondrocytes and by cells that are transdifferentiating further and exhibit an osteocytic phenotype, and moreover, that expression of OP is closely associated with calcifying foci in the extracellular matrix.     

Detection of EBV RNA (EBER-1 and EBER-2) in malaria lymph nodes by in situ hybridization

Acute Plasmodium falciparum malaria in African children allows expansion of latent Epstein-Barr virus infection, leading to colonization of lymph nodes by virus-infected lymphoblasts in 60% of cases as demonstrated by in situ hybridization for the detection of EBER-1 and EBER-2 RNA. This probably arises against a background of malaria-induced immunosuppression to EBV and concurrent lymphoid activation. The relevance of the results to the pathogenesis of African endemic Burkitt's lymphoma is discussed.     

Transient expression of acetylcholinesterase messenger RNA and enzyme activity in developing rat thalamus studied by quantitative histochemistry and in situ hybridization

The molecular basis for transient expression of acetylcholinesterase in noncholinergic regions of the early postnatal rat brain was studied by in situ hybridization histochemistry. A 33P-labelled 63-mer DNA oligonucleotide was used to probe acetylcholinesterase messenger RNA in the brains of rat pups at one, two, six, nine, 12, 16 and 21 days of age (birth = day 0). Cryostat brain-sections were hybridized with probe and exposed to X-ray film or emulsion coatings. Acetylcholinesterase messenger RNA was quantitated by counting silver grains and by measuring X-ray film density with video imaging and computer-based densitometry. Adjacent sections were stained histochemically for acetylcholinesterase activity, also quantitated by video densitometry. Overall there was a significant correlation between apparent levels of acetylcholinesterase activity and acetylcholinesterase messenger RNA. Increases in message tended to accompany the surges of acetylcholinesterase activity that marked the maturation of thalamocortical sensory relay pathways. Acetylcholinesterase expression in the youngest rats was generally sparse but it increased markedly during the first postnatal week, especially in the sensory relay nuclei of the thalamus. Levels of message and enzyme activity in the medial and dorsolateral geniculate and the ventral posteromedial and ventral posterolateral nuclei rose to a peak, typically about day 9. Beyond this time there was a gradual decline. By day 21 the staining and in situ hybridization patterns resembled those in adult brains, whose thalamic relay nuclei are impoverished in acetylcholinesterase activity and messenger RNA. Thus, acetylcholinesterase expression is strongly modulated in certain thalamic systems as they undergo neural morphogenesis.