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Biomedical subjects

K Nagasaki

Publications and source records attributed to K Nagasaki.

At least 37 records · Page 2Linked to original sources

Circulating parathyroid hormone-related protein (109-141) in malignancy-associated hypercalcemia.

For differential diagnosis between hypercalcemia-induced bone metastasis and humoral hypercalcemia of malignancy (HHM), serum parathyroid hormone-related protein (PTHrP) concentrations were measured in normal subjects and patients with malignancy-associated hypercalcemia according to the presence or absence of bone metastasis, using a new sensitive PTHrP(109-141) radioimmunoassay system. The serum PTHrP(109-141) levels in all of 14 patients without bone metastasis were significantly higher than those in normal subjects. However, in four patients with hypercalcemia associated with bone metastasis the levels were nearly the same as those in normal subjects. The time course in two hypercalcemic patients with esophageal carcinoma revealed that serum PTHrP(109-141) levels were elevated before hypercalcemia developed and that changes in PTHrP(109-141) and corrected serum calcium levels were significantly correlated. These findings suggest that determination of serum PTHrP(109-141) may be clinically important not only for differential diagnosis of HHM but also as a useful predictive marker of hypercalcemia.

Adolescent↗

Triple paraneoplastic syndrome of hypercalcemia, leukocytosis and cachexia in two human tumor xenografts in nude mice.

Nude mice bearing the human oral cavity carcinoma cell line OCC-1, and the lung cancer cell line LC-1, developed a triple paraneoplastic syndrome consisting of hypercalcemia, cachexia and leukocytosis. All of these abnormalities disappeared rapidly after surgical resection of the tumors, suggesting their ectopic humoral nature. Search for the factors responsible for the respective abnormalities revealed that the production of parathyroid hormone-related protein and colony-stimulating factors (CSFs), mainly granulocyte-CSF, by the tumors could explain the hypercalcemia and leukocytosis, respectively. With regard to the severe cachexia, the production of two cachexia-associated cytokines, interleukin-6 and leukemia inhibitory factor, was able to explain the syndrome in OCC-1 bearing nude mice; however, the factor responsible in LC-1 bearing nude mice could not be identified. The triple paraneoplastic syndrome that developed in these two animal models could be explained partly by concomitant production of the peptide hormone and cytokines by cancer cells. These animal models may be very useful for the evaluation of diagnostic and therapeutic modalities for humoral abnormalities.

Animals↗

A novel calcium-binding protein in amniotic fluid, CAAF1: its molecular cloning and tissue distribution.

We found by using a 45Ca2+ overlay technique a large amount of Ca(2+)-binding activity in bovine amniotic fluid from which a novel calcium-binding protein (CaBP) was purified and is referred to as CAAF1 (calcium-binding protein in amniotic fluid-1), with an apparent molecular mass of 8 kDa determined by N-tris(hydroxymethyl)-methylglycine/ SDS-PAGE. It was structurally homologous with MRP/calgranulin proteins (MRP8/calgranulin A and MRP14/calgranulin B), members of the S100 protein family, which are abundantly found in the cytoplasm of granulocytes and macrophages. CAAF1 lacked the predicted signal peptide sequence, which is consistent with other CaBPs. The tissue and cellular distribution of CAAF1 was determined by monoclonal antibodies developed against this protein. Its immunoreactivity was found in squamous epithelial cells, neutrophils, and some macrophages throughout the fetal body. An especially characteristic staining pattern was obtained in the squamous epithelium, including that of the esophagus, skin and amnion: CAAF1 was detected in the suprabasal squamous epithelial cells undergoing differentiation, but not in the cells in the proliferating basal layer. Northern blot analysis also showed that CAAF1 mRNA was highly expressed in bovine fetal esophagus and skin. On the other hand, our ELISA studies showed that CAAF1 protein was present in amniotic fluid at a concentration of about 120 nM, which was over 30 times as high as that in the fetal serum. These results suggested that CAAF1 is one of the stage-specific proteins in the differentiation of squamous epithelial cells, and that CAAF1 is preferentially produced by fetal squamous epithelial cells, including epidermal keratinocytes and amniotic epithelial cells, and it is stored in the amniotic fluid during embryogenesis.

Amino Acid Sequence↗

The role of angiogenesis in the tumor growth of Syrian hamster pancreatic cancer cell line HPD-NR.

BACKGROUND/AIMS: New therapeutic approach is required for pancreatic cancer, one of the most intractable malignancies. The role of angiogenesis in the tumor growth of a Syrian hamster pancreatic cancer cell line HPD-NR, which closely resembles its human counterpart, was investigated. METHODS: Angiogenic activity was measured as stimulation of growth of human umbilical vein endothelial cells (HUVEC), and angiogenic factors produced by HPD-NR cells were identified by reverse-transcription polymerase chain reaction and Northern blot analysis. Then in vitro and in vivo antitumor effects of a potent angiogenesis inhibitor, O-(chloroacetylcarbamoyl)fumagillol (AGM-1470), were examined. RESULTS: The conditioned medium of HPD-NR cells stimulated the growth of HUVEC, and four hamster angiogenic factors were detected with an overexpression of transforming growth factor alpha and vascular endothelial growth factor messenger RNAs. AGM-1470 specifically inhibited the growth of HUVEC and that of HPD-NR tumors in vivo with decreased vascularity of the tumors but not the growth of HPD-NR cells in vitro. CONCLUSIONS: The results suggest that angiogenesis plays an important role in tumor growth of HPD-NR cells and can be a new target of medical therapy for pancreatic cancer.

Animals↗

FUS/TLS-CHOP chimeric transcripts in liposarcoma tissues.

Myxoid liposarcoma and malignant fibrous histiocytoma (MFH) are common soft tissue sarcomas of adulthood. Histopathologically they often show intratumor heterogeneity. In some cases, differential diagnosis of liposarcoma and MFH is difficult. It has been reported that myxoid liposarcomas are characterized by chromosomal translocation t (12; 16) (q13; p11), and that this results in two types (type I and type II) of FUS/TLS-CHOP fusion transcripts. In this study, the FUS/TLS-CHOP chimeric transcripts in seven malignant soft tissue tumors of Asian patients were analyzed by reverse transcription-polymerase chain reaction, DNA blot hybridization and nucleotide sequencing. One myxoid liposarcoma and two round cell liposarcomas possessed a chimeric transcript whose fusion point was the same as that of the type I fusion transcript reported previously for myxoid liposarcoma. We were thus able to detect the type I FUS/TLS-CHOP fusion transcript in clinical specimens of liposarcoma from Asian patients, including the first examples of round cell liposarcoma. These results suggest that the detection of FUS/TLS-CHOP chimeric transcripts or chimeric genes can be used as a diagnostic tool for the pathological diagnosis of liposarcomas.

Adult↗

PP1 gamma 2, a testis-specific protein-serine/threonine-phosphatase type 1 catalytic subunit, is associated with a protein having high sequence homology with the 78-kDa glucose-regulated protein, a member of the 70-kDa heat shock protein family.

Protein phosphatase 1 gamma 2 (PP1 gamma 2) is a testis-specific isotype of the protein-serine/threonine-phosphatase type 1 catalytic subunit. Three native forms of PP1 gamma 2 were detected in a crude fraction of rat testis by electrophoresis in a nondenaturing polyacrylamide gel. We purified a major native form of PP1 gamma 2 to homogeneity by successive column chromatography on Mono Q-Sepharose, EAH-agarose, protamine-agarose, and G3000SW and by electrophoresis in a nondenaturing polyacrylamide gel. The G3000SW-purified PP1 gamma 2 native form had an apparent molecular mass of 170 kDa. The purified holoenzyme from nondenaturing polyacrylamide gel was composed of the catalytic subunit and two noncatalytic subunits, of 78 kDa and 55 kDa. Partial amino acid sequence analysis of the 78-kDa protein suggested that it is the 78-kDa glucose-regulated protein, a member of the 70-kDa heat shock protein family. The 78-kDa protein may possibly function as a chaperone or by confining substrate specificity of PP1 gamma 2.

Amino Acid Sequence↗

Cloning and functional expression of poly(ADP-ribose) polymerase cDNA from Sarcophaga peregrina.

A cDNA spanning the entire coding region for poly(ADP-ribose) polymerase (PARP) of Sarcophaga peregrina was isolated and the nucleotide sequence was determined. The longest open reading frame encodes a polypeptide of 996 amino acid residues with a molecular mass of 113,033 Da. The similarities to the human PARP in amino acid sequence were relatively low in the DNA-binding and auto-modification domains, but very high in the C-terminal catalytic domain: identity of amino acids is 34% in the N-terminal DNA-binding domain (residues 1-369), 27% in the auto-modification domain (residues 370-507), and 56% in the C-terminal NAD-binding domain (residues 508-996). Two zinc-fingers (C-X2-C-X28-H-X2-C and C-X2-C-X31-H-X2-C)2 and a basic region in the N-terminal DNA-binding domain recognized in other PARP are conserved. Downstream of the basic region, another cysteine-rich motif (C-X2-C-X13-C-X9-C), a putative zinc-finger, was found to be well conserved in the PARP of Sarcophaga, Drosophila and human. A leucine-zipper motif (L-X6-L-X6-L-X6-L) which was found in the auto-modification domain of Drosophila PARP, is disrupted in the Sarcophaga enzyme: the second leucine is replaced by proline, and the third leucine by valine. Full-length cDNA for Sarcophaga PARP was cloned into an expression plasmid and expressed in Escherichia coli. A lysate of E. coli cells containing expressed protein reacted with antibody against Sarcophaga PARP, and PARP activity was detected. Thus, we conclude that isolated cDNA encodes a functional Sarcophaga PARP cDNA.

Amino Acid Sequence↗

Molecular cloning of a cDNA encoding an inducible calmodulin-dependent nitric-oxide synthase from rat liver and its expression in COS 1 cells.

Calmodulin-dependent nitric-oxide synthase, with an apparent molecular mass of 125 kDa, was induced in the liver of rats treated with Propionibacterium acnes and Escherichia coli lipopolysaccharide. Clones were isolated from a cDNA library obtained from induced rat liver using oligonucleotide probes which were synthesized based on the amino acid sequences of peptides of the purified enzyme. Four overlapping cDNA clones for a 3.8-kbp region were isolated and the nucleotide sequences were determined. These clones encompassed an open-reading frame of 3441 bases encoding 1147 amino acids. The deduced amino acid sequence of the cDNA suggested that the protein contains binding sites for NADPH, FAD and FMN. The structure of the possible calmodulin-binding site, consisting of a strongly hydrophobic region surrounded by basic amino acids, is present. The full-length cDNA was expressed in COS 1 cells under the control of a cytomegalovirus promoter and the expressed enzyme was found to be a calmodulin-dependent nitric-oxide synthase. A structural comparison suggested that the liver nitric-oxide synthase is the same as the macrophage enzyme. Northern-blot analysis showed that the mRNA in the liver is approximately 4.2 kb long and is induced transcriptionally by treatment with P. acnes and lipopolysaccharide.

Amino Acid Oxidoreductases↗

The development of hypercalcemia in a patient with an ovarian tumor producing parathyroid hormone-related protein.

Hypercalcemia developed in a 34-year-old woman with a clear cell carcinoma of the ovary. Osseous involvement with the tumor cells was not present. Primary hyperparathyroidism was absent. Operative partial resection of the metastatic supraclavicular lymph node, followed by radiation therapy, decreased her serum calcium concentrations. This case belongs to the category of humoral hypercalcemia of malignancy (HHM). Detection of a significant quantity of immunoreactive parathyroid hormone-related protein (PTH-rP) in the metastatic lymph node suggested that the HHM of the patient was induced by PTH-rP produced by the tumor. From a review of 17 cases of ovarian tumors showing HHM-like morbidity, it was found that clear cell carcinoma and cystadenocarcinoma were the major types of ovarian tumors associated with HHM.

Adenocarcinoma↗

Comparison of effects of oxygen and antioxidative enzymes on cell growth between retinal pigment epithelial cells and vascular endothelial cells in vitro.

We assayed the proliferation of porcine retinal pigment epithelial (RPE) cells, bovine melanotic and amelanotic RPE cells, and bovine aortic endothelial cells exposed to 20, 10 and 5% oxygen and compared their responses to oxygen and antioxidative enzymes (superoxide dismutase and catalase). Irrespective of the cell type, the cell growth was optimal in 10% oxygen that is most closely approximating to the oxygen concentration prevailing in the cellular environment of the choroid and the retina in vivo. However, the effects of oxygen concentrations were cell specific because bovine endothelial cells were influenced by lowering of oxygen concentrations more significantly than bovine and porcine RPE cells. Moreover, addition of antioxidative enzymes caused significant improvement in growth of porcine RPE cells, but had no significant effects on bovine RPE cells. On the contrary, the bovine vascular endothelial cells represented the only one cell type significantly inhibited by antioxidative enzymes, i.e., a decrease in reactive intermediates of oxygen was seen in the media. Our results show that responses of vascular endothelial cells to reactive species of oxygen were distinctly different from those of RPE cells and more easily influenced by the environment related to hypoxia than RPE cells.

Animals↗

Hypercalcemia in patients with esophageal carcinoma. The pathophysiologic role of parathyroid hormone-related protein.

To elucidate the actual incidence of hypercalcemia in patients with esophageal carcinoma, 382 consecutive cases admitted to the National Cancer Center Hospital (Tokyo, Japan) from 1983 to 1988 were investigated. Hypercalcemia was detected in 5 patients of 376 (1.3%) at the time of primary detection of cancer, and in 45 patients of 120 (38%) patients with recurrent or unresectable cancer who were monitored within 2 months of death. These observations demonstrated that this electrolyte imbalance is a frequent paraneoplastic syndrome observed in patients with advanced esophageal carcinoma. With regard to the etiology, bone metastases were detected in 13 of 49 patients with hypercalcemia; the remaining 36 patients were assumed to be induced by the production of hypercalcemic substance(s) by tumor tissues. Parathyroid hormone-related protein (PTHrP) is a newly discovered factor which increases serum calcium in vivo. The detection of PTHrP mRNA in tumor tissues as well as the production of PTHrP-like immunoreactivity by tumor tissues were closely associated with the development of hypercalcemia, suggesting that PTHrP is the major cause of hypercalcemia in patients with esophageal carcinoma.

Adult↗

Cancer cachexia syndrome developed in nude mice bearing melanoma cells producing leukemia-inhibitory factor.

Melanoma-derived lipoprotein lipase inhibitor (MLPLI) is a factor purified from the conditioned medium of a human melanoma cell line, SEKI, which induced severe cachexia in tumor-bearing nude mice. Amino acid sequencing revealed that the amino-terminal portion was identical to that of leukemia-inhibitory factor (LIF). To determine whether MLPLI is actually LIF, the expression of LIF mRNA was examined in the SEKI melanoma cell line. Northern blot analyses revealed that the cell line displayed an intense hybridizable band with a molecular size of 3.8 kilobases, suggesting that MLPLI is identical to LIF. The relationship between the development of the cancer cachexia syndrome and the expression of LIF mRNA was examined in four melanoma xenografts, SEKI, G361, A375 and MEWO, in nude mice. SEKI- and G361-bearing nude mice developed cancer cachexia syndrome, and their body weights decreased by the 25th day after the transplantation to 73.6% and 73.8% of the control, respectively. A375- and MEWO-bearing nude mice, however, did not develop the syndrome. Northern blot analyses revealed that G361 as well as SEKI expressed a large amount of LIF mRNA, but A375 and MEWO did not, suggesting a close relationship between the expression of LIF mRNA and the development of the syndrome. These data support the concept that MLPLI, or LIF, plays an important role in the development of the cancer cachexia syndrome observed in melanoma-bearing nude mice.

Animals↗

Interleukin-4 blocks parathyroid hormone-related protein-induced hypercalcemia in vivo.

Interleukin (IL)-4 inhibits bone resorption. In the present study, the effect of IL-4 on hypercalcemia in nude mice under two experimental conditions was assessed. IL-4 inhibited plasma calcium elevation induced by parathyroid hormone-related protein (PTHrP) infusion. In hypercalcemic nude mice bearing PTHrP-producing tumors, IL-4 lowered plasma calcium levels to almost the normal range. These results indicate that IL-4 blocks PTHrP-induced hypercalcemia in vivo.

Animals↗

Production of parathyroid hormone-related protein in tumour xenografts in nude mice presenting with hypercalcaemia.

This study examined the pathophysiological role of parathyroid hormone-related protein (PTHrP) in humoral hypercalcaemia of malignancy (HHM). Seven human tumour xenografts were analysed in nude mice; five tumours (KEsC-2, oesophageal carcinoma; FA-6, pancreatic carcinoma; SEKI, melanoma; Lu-65A and Lu-61, lung carcinomas) were associated with hypercalcaemia and two tumours (MIA PaCa-2, pancreatic carcinoma; PLC/PRF/5, hepatocellular carcinoma) with normocalcaemia. Northern blot analyses, radioimmunoassay and bioassay confirmed the synthesis of PTHrP-like peptides by all five tumours associated with hypercalcaemia, but not by the two associated with normocalcaemia. These observations indicated a very close relationship between the production of PTHrP and the development of HHM. Gel filtration studies of three tumour tissue extracts revealed at least two different molecules with both PTHrP-like immunological and biological activities. One peak eluted at a position between PTHrP (1-141) and cytochrome C and the other at a position identical to cytochrome C. These results suggest that PTHrP molecules with a molecular size equal to or greater than cytochrome C participate as causative agents of HHM. All five tumour xenografts caused hypercalcaemia when grown to a size of 1.5 g in nude mice. Under cell culture conditions, four original cell lines, KEsC-2, FA-6, SEKI and Lu-65A secreted 450.0, 45.0, 3.6 and 3.0 pmol of immunoreactive PTHrP/1.5 x 10(9) cells (approximately equivalent to 1.5 g wet weight) 24 h-1 into their respective culture media. Since a subcutaneous infusion of 100 pmol 24 h-1 of PTHrP (1-34) into nude mice was sufficient to induce significant hypercalcaemia, we speculate that PTHrP alone released from tumour cells could induce hypercalcaemia at least in the case of KEsC-2, and possibly in FA-6. With regard to other tumours associated with hypercalcaemia, further examination of PTHrP and other compounds with bone-resorbing activity in these transplantable tumours is required to obtain a better understanding of this morbidity.

Animals↗

Production of endothelin in human cancer cell lines.

Endothelin (ET)-1 is a vasoconstrictor peptide derived from endothelial cells and now known to be a local regulator of vascular tonus. Recent studies, however, have revealed that ET-1 functions also as growth factor in various cells. By using a specific ET-1 radioimmunoassay, immunoreactive (IR) ET-1, ranging from 4.2 to 150 pM (minimum detectable amount, 4.0 pM), was detected in 13 of 42 human cancer cell lines. The frequencies of IR-ET-1 production and its concentrations were high in mammary, pancreatic, and colon carcinoma cell lines. IR-ET-1 produced by cancer cells possessed the same molecular size as synthetic ET-1 and also had ET-1-like biological activity. Moreover, Northern blot analysis revealed bands corresponding to ET-1 mRNA in cancer cell lines, indicating that IR-ET-1 produced by cancer cells is a product of the ET-1 gene. Since ET-1 in the spent media is present in a sufficient amount to stimulate cellular growth, we sought ET-1 receptors in four pancreatic carcinoma cell lines and human skin fibroblasts. No ET-1 receptors were detected in the pancreatic carcinoma cell lines. However, human skin fibroblasts possessed a large number of ET-1 receptors. This finding raises the possibility that ET-1 produced by cancer cells plays a modulatory role in the growth of stromal cells surrounding cancer cells.

Cell Line↗

Parathyroid hormone-related protein is a possible autocrine growth inhibitor for lymphocytes.

Adult T-cell leukemia (ATL)-related cells have the ability to produce a newly-isolated calcium-regulating protein, parathyroid hormone-related protein (PTHrP). The present study revealed that lectin-stimulated normal lymphocytes produce immunoreactive (IR)-PTHrP. When the T-cell-enriched fraction was purified from normal lymphocytes and then treated with lectin, a similar amount of IR-PTHrP was detected, suggesting that IR-PTHrP is an actual product of T-lymphocytes. A biologically active fragment of PTHrP, PTHrP(1-34), suppressed DNA synthesis in lectin-stimulated lymphocytes at concentrations greater than 50 pg/mL; the same concentration range of IR-PTHrP detected in the cultured media of lectin-stimulated lymphocytes. Therefore, it is reasonable to postulate that PTHrP is a cytokine inhibiting the cellular growth of normal lymphocytes.

Cell Division↗

Parathyroid hormone-related protein in tumor tissues obtained from patients with humoral hypercalcemia of malignancy.

We assessed the relationship between the parathyroid hormone-related protein (PTHrP) and the development of humoral hypercalcemia of malignancy (i.e., hypercalcemia due to the production by solid tumors of hypercalcemic factors) by assaying tumor extracts from hypercalcemic and normocalcemic patients with cancer for immunoreactive PTHrP contents. Immunoreactive PTHrP was demonstrated in extracts of 21 of 22 tumor tissues obtained from 22 patients with humoral hypercalcemia of malignancy. Immunoreactive PTHrP was rarely seen in tumor tissue extracts obtained from 34 normocalcemic patients with cancer and two hypercalcemic patients with cancer with severe bone metastases. Gel filtration studies of tumor extracts revealed a molecular-size heterogeneity of immunoreactive PTHrP. These radioimmunoassay data indicate a close relationship between detection of PTHrP in tumor tissues and the development of humoral hypercalcemia of malignancy.

Adult↗