Biomedical subjects

H Sonobe

Publications and source records attributed to H Sonobe.

At least 19 recordsLinked to original sources

PubMed2006

A ubiquitin ligase, skeletrophin, is a negative regulator of melanoma invasion.

Skeletrophin (mindbomb homolog 2 (MIB2)) is a RING (Really Interesting New Gene) finger-dependent ubiquitin ligase, which targets the intracellular region of Notch ligands. A previous immunohistochemical study demonstrated that skeletrophin was downregulated in many melanomas. In the present study, we have identified a promoter region of skeletrophin on a CpG island and detected aberrant methylation of this region in six of 31 invasive melanomas, but in none of 25 benign nevi or five non-invasive superficial spreading melanomas. Subsequently, we found that a zinc-finger transcriptional factor Snail, which is overexpressed in many melanoma cells, repressed the skeletrophin promoter activity via an E-box-related element and was involved in downregulation of skeletrophin. An activator protein-2, which has a tumor suppressor-like role in melanoma, increased skeletrophin expression. Interestingly, exogenously expressed skeletrophin reduced melanoma cell invasion in vitro and in vivo. Colony formation in soft agar was also reduced in a RING motif-dependent manner, without affecting cell growth. We also found that skeletrophin downregulated transcription of the Met oncogene, which encodes the hepatocyte growth factor receptor and plays a role in the determination of the invasive phenotype of many malignant tumors. Finally, exogenously expressed skeletrophin, but not its RING mutant, increased transcription of Hes1 gene, a downstream effector of Notch pathway in melanoma cells. The present findings indicate that skeletrophin might be a novel suppressor factor for melanoma invasion.

Animals↗

PubMed2001

Analysis of transforming activity of human synovial sarcoma-associated chimeric protein SYT-SSX1 bound to chromatin remodeling factor hBRM/hSNF2 alpha.

Human synovial sarcoma has been shown to exclusively harbor the chromosomal translocation t(X;18) that produces the chimeric gene SYT-SSX. However, the role of SYT-SSX in cellular transformation remains unclear. In this study, we have established 3Y1 rat fibroblast cell lines that constitutively express SYT, SSX1, and SYT-SSX1 and found that SYT-SSX1 promoted growth rate in culture, anchorage-independent growth in soft agar, and tumor formation in nude mice. Deletion of the N-terminal 181 amino acids of SYT-SSX1 caused loss of its transforming activity. Furthermore, association of SYT-SSX1 with the chromatin remodeling factor hBRM/hSNF2 alpha, which regulates transcription, was demonstrated in both SYT-SSX1-expressing 3Y1 cells and in the human synovial sarcoma cell line HS-SY-II. The binding region between the two molecules was shown to reside within the N-terminal 181 amino acids stretch (aa 1--181) of SYT-SSX1 and 50 amino acids (aa 156--205) of hBRM/hSNF2 alpha and we found that the overexpression of this binding region of hBRM/hSNF2 alpha significantly suppressed the anchorage-independent growth of SYT-SSX1-expressing 3Y1 cells. To analyze the transcriptional regulation by SYT-SSX1, we established conditional expression system of SYT-SSX1 and examined the gene expression profiles. The down-regulation of potential tumor suppressor DCC was observed among 1,176 genes analyzed by microarray analysis, and semi-quantitative reverse transcription--PCR confirmed this finding. These data clearly demonstrate transforming activity of human oncogene SYT-SSX1 and also involvement of chromatin remodeling factor hBRM/hSNF2 alpha in human cancer.

Agar↗

PubMed2001

The molt-inhibiting hormone in the American crayfish Procambarus clarkii: its chemical synthesis and biological activity.

The molt-inhibiting hormone of the American crayfish Procambarus clarkii (Prc-MIH), a 75-residue polypeptide containing three disulfide bridges, was synthesized by chemical ligation of two peptides, i.e., synthetic Prc-MIH(1-39) and Prc-MIH(40-75)-NH(2), and by subsequent folding to form the native disulfide-containing peptide molecule. The synthetic peptide was comparable to the natural Prc-MIH in inhibiting ecdysteroid secretion by in vitro bioassay and shared features with the natural Prc-MIH in some biochemical analyses. These results indicate that the chemical ligation method can be used for the synthesis of Prc-MIH. Furthermore, it was demonstrated that synthetic Prc-MIH has hyperglycemic activity, although the activity was weaker than that of the authentic crustacean hyperglycemic hormone in the American crayfish. To examine the structural requirement of the Prc-MIH for eliciting biological activity, an antibody raised against the C-terminal region (residues 55-75) and two synthetic peptides, i.e., a core region (residues 1-54) containing three disulfide bridges and the C-terminal region, were utilized. It is suggested that Prc-MIH exerts its activities through coordination between the core region and the C-terminal region.

Animals↗

PubMed2001

T-cadherin (CDH13, H-cadherin) expression downregulated surfactant protein D in bronchioloalveolar cells.

T cadherin is a unique cadherin cell adhesion molecule that is anchored to the surface membrane through a glycosyl phosphatidyl inositol (GPI) moiety. In the present study, we postulated that T cadherin could regulate surfactant protein (SP)-D gene expression in human bronchioloalveolar type-II cells. We transfected A549 cells (human lung cancer cell line with alveolar type-II cell characteristics) with the T-cadherin expression vector. Both original and control plasmid-transfected A549 cells expressed SP-D; however, neither human nor murine T-cadherin-transfected A549 cells expressed SP-D mRNA. The downregulation of SP-D production in human T-cadherin-expressed A549 cells was also demonstrated using Western immunoblotting techniques. Control vector-transfected A549 cells showed a positive band of SP-D but not of T cadherin. In contrast, T-cadherin-transfected A549 cells, which expressed T-cadherin protein, did not produce SP-D. We further examined the relationship of T cadherin and SP-D expression in secondary pulmonary alveolar proteinosis associated with hematolymphoid malignancies. SP-D was detected in bronchioloalveolar type-II cells in alveolar proteinosis. However, little or no T-cadherin expression was detected in alveolar type-II cells in these patients. To our knowledge, this is the first report describing an effect of cadherin on SP production in bronchioloalveolar cells.

Adenocarcinoma, Bronchiolo-Alveolar↗

PubMed2001

Reduced human mismatch repair protein expression in the development of precancerous skin lesions to squamous cell carcinoma.

Loss of human mismatch repair (hMSH2) gene function has been linked to hereditary non-polyposis colorectal cancer (HNPCC), Muir-Torre syndrome (MTS), and sporadic cancers, excluding skin cancers unrelated to MTS. We immunohistochemically examined 125 squamous cell carcinomas (SCCs) using a monoclonal antibody to the hMSH2 protein and compared the results with those for 106 precursor lesions of SCC, consisting of actinic keratosis (AK), Bowenoid type of actinic keratosis (BAK), and Bowen's disease (BOD). In contrast to the homogeneous immunoreactivity of proliferating cells composed of AK, BAK, and BOD, heterogeneous and diminished immunostaining to hMSH2 was observed in tumor cells of SCCs examined. In addition, two SCCs (2 of 125; 1.6%) at multiple loci exhibited a complete lack of immunoreaction to hMSH2. Immunohistochemical staining of hMSH2 was semiquantitatively scored as 0 (0% of total cells examined), 1 (less than 10%), 2 (10-50%), or 3 (more than 50%). Percentage preservation of and average score for hMSH2 expression in normal, AK, BAK, BOD, and SCC were 56% and 2.06, 100% and 2.80, 94% and 2.88, 83% and 2.78, 63% and 2.36, respectively. The percentage preservation of and average scores for hMSH2 in AK, BAK, and BOD were significantly higher than those in presumably normal skin (P<0.01). There were no significant differences in the percentage preservation of and average scores for hMSH2 between presumably normal skin and SCC. The score for hMSH2 expression was significantly correlated with score for sun exposure in presumably normal skin of each lesion (R=0.70). These findings for hMSH2 expression in precursor lesions and SCC suggest that promotion or activation of hMSH2 expression may be induced by the increased DNA damage caused by sun exposure and that diminished expression of it might occur according to the transformation from precancerous lesions to SCC.

Adult↗

PubMed2001

Angiomyofibroblastoma of the vulva: report of a case.

A 45-year-old woman was first seen by us 2 years after becoming aware of a slightly painful subcutaneous mass in her left vulva. The mass was 7.5 x 3.0 cm in size, well circumscribed, mobile, and rubbery. It was at first clinically considered to be a benign tumor. Microscopically, the resected mass was composed of spindle or polygonal tumor cells which were cellularly or hypocellularly arranged with perivascular accentuation in a mucoid or fibrocollagenous background. Immunohistochemically, myxoid tumor cells were positive for vimentin but not for alpha-smooth muscle actin, CD34, CD31, desmin, or S-100 protein. The tumor was diagnosed as an angiomyofibroblastoma (AMBF), based on the typical findings of histology and immunohistochemistry. There are many histological types of vulvar tumors, and establishing a preoperative diagnosis is difficult in many patients. Rapid intraoperative pathological diagnosis should be performed if possible, considering the possibility of diseases such as AMFB and aggressive angiomyxoma (AAM). When AAM is suspected, the peripheral tissues should also be resected to prevent recurrence.

Angiofibroma↗

PubMed2001

Expression of SMARCF1, a truncated form of SWI1, in neuroblastoma.

Previously we cloned and mapped a B120 gene to human chromosome 1p35-36.1 where possible suppressor genes for various neuroendocrine tumors including neuroblastoma have been mapped. Very recently, B120 was identified as a truncated form of p270, a putative human counterpart of SWI1. In the present study, expression of the B120 gene product was immunohistochemically investigated in 23 neuroblastomas. We also examined B120 expression in neural stem cells in developing brain and intact adrenal medulla. Four of 23 neuroblastomas strongly expressed B120 gene product in both cytoplasm and nucleus. The other neuroblastomas expressed B120 gene product in the nucleus; however, the intensity of staining was much weaker and equivalent to that in developing human brain stem cells in the subventricular region. B120 gene product was less strongly expressed in intact adrenal medulla. Subsequently, we performed loss of heterozygosity studies on 19 neuroblastomas using the polymorphic markers D1S195 and D1S511 located near the B120 gene. Loss of heterozygosity was observed in three of 19 tumors that abundantly expressed B120 protein. Furthermore, neuroblastoma cells were transfected with B120 expression vector. These transfected neuroblastoma cells adhered to each other and aggregated. Differential display experiments followed by reverse transcriptase-polymerase chain reaction and Northern blot analysis were performed and three molecules with altered expression in B120-transfected neuroblastoma cells were identified. One of three genes seemed to be a proliferation-related and cell cycle-related nucleolar protein, p120, encoding gene. We further characterized the genomic structure of B120. B120 appeared to be encoded by 17 exons in more than 20-kbp genomic DNA. The present findings contribute to understanding of the B120 gene, a truncated form of human SWII1, an approved term for which is SMARCF1, in normal cells and neuroblastomas.

Base Sequence↗

PubMed2001

Immunohistochemical expression and pathogenesis of BLM in the human brain and visceral organs.

Bloom syndrome (BS) involves the clinical features of telangiectatic erythema, immunodeficiency, and an increased risk for cancer. In order to clarify the pathogenetic significance of the responsible gene, BLM, which encodes a protein possessing homology to Escherichia coli RecQ helicase, the immunohistochemistry of BLM was examined in human brains and visceral organs from fetuses to adults and an adult with BS, using anti-BLM antibodies. Purkinje cells exhibited positive BLM immunoreactivity from 21 gestational weeks (GW), which transiently increased at approximately 40 GW. Neurons of the pontine tegmentum were immunolabeled from the early fetal period. In visceral organs, positive BLM immunoreactivity was observed in the Hassal corpuscles in the thymus from 24 GW, in beta-cells in the Langerhans islets of the pancreas from 36 GW, and in sperm cells and sperms of the testes from 11 years of age. But in a patient with BS, it was negative in the pancreas and testis tissues examined. The characteristic effect of BLM on specific cells in different periods suggests that the BLM gene product is closely related to neuronal development as well as immune, insulin secretory and sperm functions, which appear in different periods, and disorders of which are major symptoms of BS.

Adult↗

PubMed2001

Tetrasomy 12 in ovarian tumors of thecoma-fibroma group: A fluorescence in situ hybridization analysis using paraffin sections.

Recent cytogenetical studies have indicated that trisomy 12 is a feature of ovarian tumors in the thecoma-fibroma group. Ten cases of these ovarian tumors were studied in total, including two thecomas, two fibrothecomas, four fibromas, one cellular fibroma and one fibrosarcoma, to clarify the relationship between polysomy 12 and proliferative activity in these tumors. Each formalin-fixed, paraffin-embedded tumor tissue was examined by fluorescence in situ hybridization to determine copy numbers of chromosome 12 and by immunohistochemical staining of Ki-67 for evaluation of tumor cell proliferation. Gains of trisomy 12 were found in seven of the 10 cases, and the percentage of cells with tetrasomy 12, but not that of cells with trisomy 12, was significantly and positively correlated with percentage of Ki-67-positive cells, but significantly and inversely correlated with patient age. These findings suggest that tetrasomy 12 is an age-related aberration of chromosome 12 in ovarian tumors of the thecoma-fibroma group, and that such tumors exhibit more active proliferation in younger patients.

Adult↗

PubMed2001

Malignant phyllodes tumor of the breast with expression of osteonectin and vinculin.

Phyllodes tumor is a very rare neoplasm which accounts for 2.5% of all fibroepithelial lesions of the breast. The mesenchymal component of a malignant phyllodes tumor frequently contains heterologous components. We report a case of malignant phyllodes tumor. The patient was a 40-year-old woman with a lump on the left breast. Histological examination revealed the lump to be a malignant phyllodes tumor with foci of liposarcomatous differentiation. The mesenchymal tumor cells, including those in the liposarcomatous components, were found to express vimentin, osteonectin and vinculin. However, they showed no immunoreaction to CAM 5.2, desmin, alpha-smooth muscle actin (ASMA), neuron-specific enolase (NSE) nor S-100. Ultrastructurally, the mesenchymal tumor cells were found to have abundant cytoplasmic organelles, but there was no evidence showing their differentiation to myofibroblasts. Further studies will be necessary to elucidate the significance of vinculin and osteonectin expression in malignant phyllodes tumor.

Adult↗

PubMed2001

Primary intrapelvic seminoma in Klinefelter's syndrome.

Seminoma arising in patients with Klinefelter's syndrome is extremely rare; to our knowledge, only three cases have been reported in the English language literature. We report a case of intrapelvic seminoma in a 39-year-old man with Klinefelter's syndrome. Gross examination revealed that the tumor was a solid and irregular mass measuring 90 mm in diameter. The cut surfaces of this ill-defined tumor were yellow-white with necrotic foci. Histologically, the tumor cells were separated into lobules by branching, fibrous septa containing lymphocytes. In some parts of the tumor, a cord-like arrangement of tumor cells was present. Immunohistochemically, the tumor cells were strongly and diffusely positive for antiplacental alkaline phosphatase antibody along their cytoplasmic membranes, but negative for both chorionic gonadotrophin and alpha-fetoprotein. Based on these findings, we diagnosed this tumor as a seminoma. The testes when examined were found to be atrophic bilaterally, but with no tumor lesions. Chromosomal analysis yielded a 47XXY karyotype, compatible with Klinefelter's syndrome. These findings indicate a case of primary intrapelvic seminoma in Klinefelter's syndrome. The patient underwent intensive radiation therapy postoperatively, and he demonstrated no evidence of recurrence or metastasis during the 13-month period following surgery.

Adult↗

PubMed2001

Detection of SYT-SSX fusion gene in peripheral blood from a patient with synovial sarcoma.

This report describes a case involving a 22-year-old pregnant woman with synovial sarcoma in the thigh. The patient recognized an elastic hard mass accompanied by a dull pain in the anteromedial portion of the right thigh. Magnetic resonance imaging delineated a deep soft-tissue mass measuring 9 x 7 x 6 cm. Histologic diagnosis of poorly differentiated synovial sarcoma was made based the results of an open biopsy. In this patient, the SYT-SSX fusion gene transcript was detected by nested polymerase chain reaction (PCR) in the peripheral blood collected before biopsy. Two months after wide local resection of the tumor, multiple lung metastases developed. This is the first reported case in which tumor cells were detected by nested PCR in the peripheral blood of a patient with synovial sarcoma. These findings suggest that circulating tumor cells should be monitored because they may serve as a prognostic indicator for synovial sarcoma.

Adult↗

PubMed2001

Insufficient effect of p27(KIP1) to inhibit cyclin D1 in human esophageal cancer in vitro.

The cell cycle is controlled by protein complexes composed of cyclins and cyclin-dependent kinases. p27KIP1 (p27) is one of the Kip/Cip family cyclin-dependent kinase inhibitory proteins which negatively regulate cell cycle progression, and have been proposed as candidate tumor suppressor genes. To examine the role of p27 in the development of human esophageal squamous cell carcinoma (ESCC), we performed Western blot and immunoprecipitation analyses of the levels of expression of p27 protein in a series of ESCC cell lines. This protein was expressed at various levels in these cell lines during exponential growth. p27 level was significantly associated with that of cyclin D1, but not of cyclin E. Further cell cycle synchronization studies demonstrated that p27 was free or bound with affinity to cyclin E-CDK2 more than to cyclin D1-CDK4 or cyclin D1-CDK6. It is known that overexpression of cyclin D1 rather than cyclin E is involved in the pathogenesis of ESCC. Our findings indicated that high expression of p27 throughout the G1 to S phase may inhibit more likely cyclin E, than cyclin D1, which promotes tumor growth of esophageal squamous cell carcinoma.

Cell Cycle Proteins↗

PubMed2001

Immunohistochemical characterisation of a case of insular thyroid carcinoma.

A case of insular thyroid carcinoma arising in the right lobe of a 54-year-old male is reported. The tumour exhibited an invasive growth pattern with regional lymph node metastasis. Microscopically, the tumour was characterised by well-defined solid nests like insulae, including mature follicles containing colloid and immature follicles without colloid. Immunohistochemically, tumour cells in follicular areas predominantly exhibited immunopositivity to antithyroglobulin antibody. On the other hand, diffuse immunoreactions with anti-neuron-specific enolase (NSE), S-100 protein and Leu-7 were detected mainly in the tumour cells of solid areas. In addition, clear cytoplasmic immunoreactivity with anti-myelin basic protein (MBP) antibody was exhibited in a number of tumour cells. Ultrastructurally, many tumour cells possessed dense vacuoles, apparently containing colloid material, but intracytoplasmic neurosecretory granules were absent. The histopathological and ultrastructural characteristics of the tumour as well as its anti-thyroglobulin antibody immunoreactivity support the classical hypothesis that this neoplasm is a variant of poorly differentiated thyroid carcinoma. The positive immunohistochemical reactions for NSE, S-100, MBP and Leu-7 raise the possibility of aberrant differentiation, for example neural.

Biomarkers, Tumor↗

PubMed2000

Pauson-Khand reaction of optically active 6,7-bis(tert-butyldimethylsiloxy)non-1-en-8-ynes

Treatment of (6S,7S)-7-bis(tert-butyldimethylsiloxy)non-1-en-8-ynes with dicobalt octacarbonyl gave the corresponding cobalt complex. This complex was subsequently exposed to the Pauson-Khand conditions in the presence of a promoter such as cyclohexylamine, thioanisole, methyl isopropyl sulfide, and butyl methyl sulfide ending up with the stereoselective production of the (2S,3S,6S,7S)-7-methylbicyclo[4.3.0]nonenone derivatives instead of the expected (2S,3S,7S)-bicyclo[5.3.0]decenone species.

Journal Article↗

PubMed2000

SYT-SSX fusion proteins in synovial sarcomas: detection and characterization with new antibodies.

To identify and characterize the SYT-SSX fusion proteins in synovial sarcomas, we developed two polyclonal antibodies against the N-terminal part and for the C-terminal part of the SYT-SSX2 protein. Specificity was demonstrated on COS-7 cells transfected with two subtypes of SYT-SSX fusion genes, SYT-SSX1 and SYT-SSX2. Both antibodies recognized a single protein of 61 kDa in an immunoprecipitation of the transfected COS-7 cell lysates. These antibodies also detected the native protein of 61 kDa in the lysate of a human synovial sarcoma cell line (HS-SY41) with immunoprecipitation, and in extracts of human synovial sarcomas with western blot analysis. An immunohistochemical study, using human synovial sarcoma tissues, demonstrated that the SYT-SSX fusion proteins localized in the nucleus of the tumor cells. These antibodies provide a useful method for studying the expression of the SYT-SSX fusion proteins.

Antibodies, Neoplasm↗

PubMed2000

A giant cell angiofibroma involving 6q.

Giant cell angiofibroma, a recently proposed new clinicopathological entity, arises exclusively in the orbit in adults and histologically exhibits features intermediate between those of giant cell fibroblastoma and solitary fibrous tumor. In a typical case of giant cell angiofibroma, abnormalities of chromosome 6 with a common pattern involving 6q13 were detected together with various other chromosomal aberrations. To our knowledge, this is the first reported case of giant cell angiofibroma demonstrating chromosomal abnormalities.

Angiofibroma↗

PubMed2000

Overexpression of cyclin D1 in nonmelanocytic skin cancer.

Although the overexpression of cyclin D1 has been believed to play important roles in neoplastic transformation of some tumors, little is known about the function of cyclin D1 protein in carcinogenesis in human skin. A total of 307 patients with nonmelanocytic skin cancer, being 46 with Bowen's disease (BOD), 134 with squamous cell carcinoma (SCC) and 127 with basal cell carcinoma (BCC), were investigated immunohistochemically using monoclonal antibody to cyclin D1 by the LSAB method, to assess the expression of cyclin D1 in skin cancer including its precursors. The positive rates of cyclin D1 immunostaining in BOD, SCC and BCC were 63.0%, 69.4% and 54.3%, respectively. The positive rates in dysplasia adjoining BOD, SCC and BCC were 43.6%, 67.9% and 59.8%, respectively. In morphologically normal skin, however, only 2 cases, 1 of SCC and 1 of BCC, exhibited positive staining. These findings suggested that overexpression of cyclin D1 is an early event in dysplastic lesions of skin. Overexpression of cyclin D1 was related to sun exposure, especially in dysplasia of SCC. The score for cyclin D1 expression in dysplasia of BCC was correlated with age. Expression of cyclin D1 markedly increased from normal skin through dysplasia to BOD, but was not significantly related to the degree of SCC differentiation. These findings demonstrate that the effect of cyclin D1 overexpression is restricted to proliferation of cells, so that they gain a growth advantage, but their differentiation is not increased. Comparison with the results for p53 protein expression in these tumors, a significant correlation with cyclin D1 expression was found in dysplasia in BOD and SCC, and in patients with BCC who were less than 74 years old. These findings suggested the hypothesis that prior aberrant p53 expression may affect or regulate the overexpression of cyclin D1.

Adult↗