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T Kameya

Publications and source records attributed to T Kameya.

At least 55 records · Page 3Linked to original sources
PubMed1999

The significance of frequent and independent p53 and bcl-2 expression in large-cell neuroendocrine carcinomas of the lung.

Both p53 and bcl-2 genes are involved in regulating cell death. Reports, however, concerning the relationship between p53 and bcl-2 expression are contradictory. Large-cell neuroendocrine carcinoma (LCNEC) of the lung is a newly recognized clinicopathologic entity. p53 mutation and bcl-2 overexpression are frequent in small-cell lung carcinoma (SCLC), and we observed a close correlation between bcl-2 expression and cellular neuroendocrine (NE) differentiation in non-SCLC, so we speculated that LCNEC, an NE tumor closely related to SCLC, would exhibit high incidence of both p53 alteration and bcl-2 expression. Immunohistochemical expression of p53 and bcl-2 was evaluated on consecutive sections of 26 LCNECs, including 4 combined LCNECs. p53 accumulation and diffuse bcl-2 staining were observed in 18 (69.2%) of 26 and 24 (92.3%) of 26 LCNECs, respectively, but their immunoreactivities showed no fixed distribution relevance on consecutive sections in individual tumors. Statistical analyses yielded no relationship between p53 and bcl-2 expression (P = .47). In all of the four combined LCNECs, p53 was identically either positive or negative in both tumor cell populations with and without NE differentiation. bcl-2 immunoreactivity was observed only for the tumor cells with NE phenotype in three of the four combined LCNECs and was diffuse among the NE tumor cells but geographic in distribution among the non-NE tumor cells of the remaining one combined LCNEC. Thus, our present findings suggest that p53 and bcl-2 are expressed independently and might have distinct expression significance in LCNECs. A high incidence of p53 expression in LCNECs and equal p53 expression profiles in NE and non-NE tumor cell populations of combined LCNECs suggest that p53 alteration is primarily involved in the tumorigenesis of LCNEC. On the other hand, frequent bcl-2 expression in pure LCNECs and selective bcl-2 expression in tumor cells with NE phenotype in combined LCNECs are suggestive of a role for bcl-2 in regulating cellular NE differentiation.

Carcinoma, Neuroendocrine↗
PubMed1998

CDK4, a possible critical regulator of apoptosis in rat pheochromocytoma PC12 cells.

The function of cell cycle regulator molecules during apoptosis induced by serum withdrawal was examined in rat pheochromocytoma PC12 cells. When human cDNAs encoding cyclins, cyclin-dependent kinase 2 (CDK2), CDK4, and cell-division cycle 2 (CDC2), were introduced, only CDK4-overexpressing cells were more prone to apoptosis compared with parental cells. In the parental cells, serum withdrawal resulted in the upregulation of CDK4 protein expression 6.6-fold for the first 12 h after serum withdrawal. In contrast, CDK4 protein levels in CDK4-overexpressing cells remained constant for the first 12 h followed by a gradual decline. Expression of cyclin D1 was upregulated in both cell lines. The change in CDK4 kinase activity almost paralleled that of CDK4 protein expression. These results suggest that CDK4 kinase activity is one of the critical regulators in the apoptotic cascade in PC12 cells.

Animals↗
PubMed1998

Chromogranin B (secretogranin I), a neuroendocrine-regulated secretory protein, is sorted to exocrine secretory granules in transgenic mice.

Chromogranin B (CgB, secretogranin I) is a secretory granule matrix protein expressed in a wide variety of endocrine cells and neurons. Here we generated transgenic mice expressing CgB under the control of the human cytomegalovirus promoter. Northern and immunoblot analyses, in situ hybridization and immunocytochemistry revealed that the exocrine pancreas was the tissue with the highest level of ectopic CgB expression. Upon subcellular fractionation of the exocrine pancreas, the distribution of CgB in the various fractions was indistinguishable from that of amylase, an endogenous constituent of zymogen granules. Immunogold electron microscopy of pancreatic acinar cells showed co-localization of CgB with zymogens in Golgi cisternae, condensing vacuoles/immature granules and mature zymogen granules; the ratio of immunoreactivity of CgB to zymogens being highest in condensing vacuoles/immature granules. CgB isolated from zymogen granules of the pancreas of the transgenic mice aggregated in a mildly acidic (pH 5.5) milieu in vitro, suggesting that low pH-induced aggregation contributed to the observed concentration of CgB in condensing vacuoles. Our results show that a neuroendocrine-regulated secretory protein can be sorted to exocrine secretory granules in vivo, and imply that a key feature of CgB sorting in the trans-Golgi network of neuroendocrine cells, i.e. its aggregation-mediated concentration in the course of immature secretory granule formation, also occurs in exocrine cells although secretory protein sorting in these cells is thought to occur largely in the course of secretory granule maturation.

Animals↗
PubMed1998

Expression of HuD protein is essential for initial phase of neuronal differentiation in rat pheochromocytoma PC12 cells.

HuD is a neuronal-specific, RNA-binding protein. Here we examined the change in the expression of HuD protein during nerve growth factor-mediated differentiation of PC12 cells. As cells differentiated and extended neurites, expression of HuD gradually increased up to 1.5-fold. When HuD expression was counteracted by antisense oligonucleotide, neurite extension was completely inhibited, yet the morphology of differentiated cells remained unchanged even after that treatment. Furthermore, this morphological change correlated well with the downregulation of cyclin-dependent kinase 2 activity. These results suggest that the HuD is critically involved in the initial phase of neuronal differentiation.

Animals↗
PubMed1998

Active cyclin A-CDK2 complex, a possible critical factor for cell proliferation in human primary lung carcinomas.

Expression of cyclins A and E and cyclin-dependent kinase 2 (CDK2) was examined immunohistochemically in 190 cases of human lung carcinoma. Cyclin A and CDK2 were expressed in the majority of squamous cell carcinomas, small cell carcinomas, and large cell carcinomas, but in significantly fewer cases of adenocarcinomas. Cyclin E was expressed in a minority of all subtypes. In particular, well differentiated cells in squamous cell carcinoma stained positively for cyclin E; in contrast, cyclin A was expressed in the nonkeratinized proliferating areas of the tumor nests. Immunoblotting revealed that all these proteins were expressed at higher levels in tumor tissues than in adjacent normal tissues. Immunoprecipitation also revealed higher levels of cyclin A and cyclin E associated with CDK2 in tumor tissues. Furthermore, tumor tissues which exhibited higher cyclin A and CDK2 expression also had higher CDK2 kinase activity. However, cyclin E-associated kinase activity was barely detectable even in tumor samples exhibiting higher cyclin E expression. Consistent with these data, elevated expression of cyclin A correlated to shorter survival periods in contrast to expression of cyclin E, which correlated to longer survival periods. These results suggest that in human lung carcinomas, elevated expression of active cyclin A-CDK2 complexes with associated higher CDK2 kinase activity is critical for promoting cell cycle progression and unrestrained proliferation of tumor cells and can be a predictive marker for patients' prognosis. On the other hand, immunohistochemical detection of cyclin E-CDK2 reflects accumulation of inactive forms of protein complexes, implying differentiation or senescence of the tumor and the better prognosis.

Adenocarcinoma↗
PubMed1998

Pituitary adenylate-cyclase-activating polypeptide (PACAP) binding sites and PACAP/vasoactive intestinal polypeptide receptor expression in human pituitary adenomas.

Pituitary adenylate-cyclase-activating polypeptide (PACAP) stimulates release of several anterior pituitary hormones by interacting with PACAP receptors on pituitary cells. To learn more about the distribution and possible regulatory roles of PACAP and its receptors in human pituitary adenomas, we investigated the expression of vasoactive intestinal polypeptide (VIP) and PACAP binding sites using receptor autoradiography, PACAP and PACAP/VIP receptor (PVR) mRNAs by reverse transcription polymerase chain reaction (RT-PCR), conventional in situ hybridization, and catalyzed reporter deposition in situ hybridization (CARD-ISH) analyses. PACAP mRNA was expressed in normal human hypothalamus, which was used as a positive control, but not in pituitary adenomas. Receptor autoradiography showed PACAP types I and II binding sites in all groups of pituitary adenomas, except prolactinomas. The highest levels were present in gonadotroph and null cell adenomas. PVR-2 mRNA was expressed in normal pituitaries and in all groups of pituitary adenomas by RT-PCR, whereas PVR-1 and -3 mRNAs were expressed in all groups of pituitary adenomas, except for most prolactinomas. Conventional in situ hybridization studies with digoxigenin-labeled probes demonstrated weak staining for PVR-1, -2, and -3 mRNAs in most tissues. The CARD-ISH technique, which increased the sensitivity of the in situ hybridization method, also revealed PVR-2 mRNA expression in all adenomas, whereas PVR-1 and -3 mRNAs were detected in nearly all adenomas except for prolactinomas. The presence of PACAP mRNA in the hypothalamus, but not in normal anterior pituitary or in pituitary adenomas, and the differential expression of PVRs in adenomas indicate a selective regulatory endocrine and paracrine role of PACAP in normal and neoplastic anterior pituitary cells.

Adenoma↗
PubMed1998

Isolation of a cDNA for tryptophan synthase beta from rice and studies of its expression in a 5-methyltryptophan-resistant mutant of rice.

A cDNA clone encoding rice tryptophan synthase beta (TSB) was isolated and its transcript level was examined in TR-No. 73, a derivative of a previously isolated rice mutant (TR-1) that is resistant to 5-methyltryptophan. The cDNA sequence of the rice gene for TSB was very similar to that of genes for TSB from other plants. Northern blotting analysis revealed that the steady-state level of TSB mRNA in the 5MT-resistant mutant TR-No. 73 was 1.3 times higher than the level of TSB mRNA in control rice plants under standard conditions. The level of TSB mRNA in control rice plants decreased after treatment of plants with 5MT. Similarly, the level of TSB mRNA in TR-No. 73 initially decreased, although less so than in control rice. However, after 12 h of treatment with 5MT, the level of the transcript in TR-No. 73 returned to the level under standard conditions. The activity of tryptophan synthase (TS) in seedlings of TR-No. 73 was about 2.3 times higher than that in seedlings of control rice under standard conditions.

Amino Acid Sequence↗
PubMed1998

Large cell neuroendocrine carcinoma of the lung: a histologic and immunohistochemical study of 22 cases.

Large cell neuroendocrine carcinoma (LCNEC) of the lung is defined as a poorly differentiated and high-grade neuroendocrine tumor that is morphologically and biologically between atypical carcinoid and small cell lung carcinoma (SCLC). During a survey concerning bcl-2 protein expression in the subtypes of lung cancer, we noticed that two previously diagnosed non-SCLCs met the criteria for LCNEC. Because LCNEC is a newly recognized clinicopathologic entity and because all reported cases have been retrieved from the so-called "neuroendocrine tumor file," we suspected that LCNEC had been underdiagnosed. In the present study, we histologically reviewed 766 surgically resected lung cancers and were able to diagnose 22 (2.87%) LCNECs with the neuroendocrine features subsequently confirmed by immunostaining for multiple neuroendocrine markers. Each case stained positively for at least three general neuroendocrine markers, and 12 (54.5%) also were positive for neuroendocrine hormones. Histologically, most LCNECs showed a marked decrease in or a loss of organoid architecture and could be mistaken for poorly differentiated adenocarcinoma or squamous cell carcinoma. Because our LCNECs are the first to be identified by retrospective review of routinely diagnosed lung cancers, and 18 had been classified as non-SCLC, they may represent cases relatively difficult to diagnose. The present study shows that the most difficult diagnostic factor of LCNEC is the recognition of its light microscopic neuroendocrine features, and LCNEC must be distinguished not only from atypical carcinoid or SCLC, but also from common non-SCLC. Histologically, when an organoid architecture is subtle or absent, the rosettelike structure becomes the best marker for the recognition of neuroendocrine differentiation. Clinically, the prognosis for our LCNECs was significantly worse than that for stage-comparable non-SCLCs (p = 0.046).

Aged↗
PubMed1998

Expression of carbohydrate antigens, p80NPM/ALK, cytotoxic cell-associated antigens, and Epstein-Barr virus gene products in anaplastic large cell lymphomas.

The expression of carbohydrate antigens, including sialyl Lewis X (SLEX) and BNH9 antigen, the nucleophosmin (NPM)-anaplastic lymphoma kinase (ALK) fusion protein (p80NPM/ALK), cytotoxic cell-associated antigens, and Epstein-Barr virus (EBV) gene products in CD30+ anaplastic large cell lymphoma (ALCL) was investigated by immunohistochemistry and in situ hybridization (ISH) methods. The expression of SLEX and BNH9 antigen in ALCL was examined using CSLEX1 and BNH9, which specifically react with SLEX and oligosaccharides (H and Y haptens), respectively. SLEX was expressed in seven of 12 ALCL and BNH9 was positive for five of 12 ALCL. With respect to the relationship between SLEX and BNH9 expression in ALCL, some ALCL expressed both antigens, which suggests that they might have an increased or preserved activity of glycosyltransferase that is responsible for the synthesis of the type I or type II core sequences, although other ALCL expressed either SLEX or BNH9. To detect p80NPM/ALK in ALCL, the sections were immunostained with an anti-p80 antibody. Three of 12 ALCL expressed the NPM/ALK-encoded p80 protein. All three ALCL positive for p80NPM/ALK expressed SLEX and two of them were stained with BNH9, which raised the possibility that p80 overexpression may be involved in the aberrant expression of type I or type II chains with varying degrees of fucosylation or sialylation. While the expression of cytotoxic cell-associated antigens such as CD8, CD56 and T cell intercellular antigen 1 (TIA-1) in ALCL was immunohistochemically examined, none of the 12 ALCL expressed CD56 and only one case expressed CD8. TIA-1 was expressed in seven of 12 ALCL. Four of five BNH9-positive cases expressed TIA-1, suggesting that BNH9-positive cases tended to have TIA-1. In situ hybridization studies using an EBV-encoded RNA-1 (EBER-1) probe were performed on 12 ALCL to detect EBV in the lymphoma cells. EBER-1 signals were detected in the small lymphocytes but not in the lymphoma cells of two ALCL. However, latent membrane protein 1 immunoreactivity was found in one case. These results appear to indicate that there is no strong association between EBV and ALCL.

Adolescent↗
PubMed1998

High prevalence of T354P sodium/iodide symporter gene mutation in Japanese patients with iodide transport defect who have heterogeneous clinical pictures.

A missense and loss of function mutation of the Na+/I- symporter (NIS) gene, T354P [Thr354-->Pro (ACA-->CCA)], was found in the homozygous state in two unrelated Japanese patients with iodide transport defect. In this study we have identified the homozygous T354P NIS germline mutation in seven Japanese patients, including one previously reported, from five unrelated families. No other nucleotide changes were found in the coding regions and the exon-intron boundaries of the NIS gene in these seven patients. These results suggest a common prevalence of the T354P mutation in Japanese patients. Although these seven patients have the identical NIS mutation, T354P, marked heterogeneity in clinical pictures, especially concerning goiter and hypothyroidism, were noted among them. Therefore, another factor(s), but not the nature of the NIS mutation, may account for the clinical heterogeneity among patients with the iodide transport defect. We have previously reported that the NIS messenger ribonucleic acid was markedly increased in the thyroid of a patient with the homozygous T354P mutation. In this study we demonstrated that the NIS proteins in the patients' thyroids were significantly increased (approximately 10-fold) by Western blot analysis of integral membrane proteins using an antibody against the C-terminal peptide of the human NIS. Furthermore, we showed by immunohistochemical staining that the T354P mutant NIS proteins were overexpressed in the basal and lateral plasma membranes of patients' thyrocytes.

Adult↗
PubMed1998

A functional thyrotropin- and growth hormone-secreting pituitary adenoma with a ultrastructurally monomorphic feature: a case study.

A 38-yr-old female with a TSH- and GH-secreting pituitary adenoma is described, who had both overt symptoms, hyperthyroidism and acromegaly. Her serum TSH was not suppressed despite high concentrations of free T3 and free T4, and her alpha-subunit/TSH molar ratio was high. Her serum GH was consistently high, and was not suppressed by an oral glucose tolerance test. Preoperative testing revealed that, although the TSH response was impaired, TSH, alpha-subunit and GH were increased by TRH injection, and that these hormones were reduced by bromocriptine or somatostatin analog. Although she did not have hyperprolactinemia, the in vitro culture and immunohistochemical studies revealed that the adenoma cells produced and released PRL, in addition to TSH, alpha-subunit and GH. Immunohistochemical studies showed the presence of GH in the cytoplasm of many adenoma cells. TSH beta-positive adenoma cells were less frequently seen than GH-positive adenoma cells. No cells showed the coexistence of GH and TSH beta, and a few cells were positive for PRL. By electron microscopy, the adenoma was found to be composed of a single cell type resembling thyrotrophs, and did not have any characteristics of somatotrophs. This case was considered to be of interest, because the adenoma was ultrastructurally monomorphous, but immunohistochemically polymorphous.

Acromegaly↗
PubMed1998

[Immunohistochemical staining of thymidine phosphorylase in primary colorectal carcinoma and metastases].

Thymidine phosphorylase (TdRPase) is an enzyme involved in the pyrimidine metabolism. It was reported that many cancers contained higher levels of TdRPase than normal tissues. And TdRPase has been reported to be identical with the platelet-derived endothelial cell growth factor. To clarify the distribution of TdRPase in primary and metastatic colorectal cancer, we carried out immunohistochemical staining of formalin-fixed specimens. We investigated 35 primary colorectal cancers resected surgically, 27 hepatic metastases and 8 lung metastases from colorectal carcinoma. TdRPase was highly expressed in primary colorectal cancer with lung metastases (100.0%) and surgically resected lung metastases cancer (87.5%). The staining correspondence between primary colorectal cancer and metastases was 19 cases (70.4%) in the liver metastases and 7 cases (87.5%) in the surgically resected lung metastases. The above results suggested that immunohistochemical staining for primary colorectal cancer may provide information about the sensitivity of metastases to the chemotherapy.

Adult↗
PubMed1998

Somatic mutations of multiple endocrine neoplasia type 1 gene in the sporadic endocrine tumors.

Endocrine tumors of the parathyroid and pancreas are encountered either as sporadic type or as part of multiple endocrine neoplasia type 1 (MEN 1). A high frequency of the loss of heterozygosity (LOH) has been observed in tumors of the sporadic type in the locus of the MEN 1 gene, which has recently been cloned and designated the menin gene. It would be of great interest to determine whether somatic mutations in the menin gene are responsible for the sporadic endocrine tumors. For this purpose, we have investigated the menin gene mutations in 21 sporadic parathyroid adenomas, 2 parathyroid carcinomas, 4 sporadic insulinomas, and 1 malignant VIP (vasoactive intestinal polypeptide)oma with WDHA (watery diarrhea, hypokalemia, and achlorhydria) syndrome, using PCR-single strand conformation polymorphism analysis and DNA sequencing. In none of these cases did the patient have a family history or other possible association with MEN 1. We have discovered somatic point mutations in two parathyroid adenomas (A340T and A541T), in one insulinoma (T429K), and in the malignant VIPoma (W198X). In addition, we have found two polymorphisms (D418D and V367V) in two parathyroid carcinomas and two parathyroid adenomas. Of these mutations and polymorphisms, three (A340T, T429K, and V367V) are first reported here, in the present article. Our results indicate that somatic mutations of the menin gene are responsible for a proportion of the sporadic parathyroid adenomas and pancreatic islet cell tumors.

Adenoma↗
PubMed1998

[Method of preventing hepatic artery occlusion during continuous intrahepatic arterial infusion chemotherapy of 5-FU].

A randomized clinical trial of combined use of steroids, which have a vascular endothelium-protecting action, was performed to develop a method to prevent hepatic artery occlusion during continuous intrahepatic arterial infusion chemotherapy with 5-FU. The steroid used was dexamethasone palmitate (Limethason), which has a high rate of uptake by endothelial cells. The 24 patients with advanced colorectal cancer were divided into 2 groups randomly and both were treated with 5-FU 250 mg/day by continuous hepatic arterial infusion for three weeks. The weekly dose was 5-FU 7 V (1,750 mg) adjusted to 50 ml with physiological saline in Group A and 5-FU 7 V (1,750 mg) adjusted to 50 ml with Limethason 1 A (4.0 mg of dexamethasone palmitate) in Group B. The reservoir was replaced every week. No changes in the mixture (appearance, pH, granule diameter, dexamethasone palmitate content) were observed up to one week. Hepatic arterial stenosis was observed in 8 cases in Group A (67%), but was not observed in any of the cases in Group B. The above results indicated that Limethason has a preventive effect against hepatic artery occlusion.

Anti-Inflammatory Agents↗
PubMed1998

Neuron-specific enolase-producing epithelioid leiomyosarcoma with gross vascular invasion and intracardiac involvement.

We present an unusual case of epithelioid leiomyosarcoma in the right shoulder. A 10-cm tumor eroding the right scapula occurred in a 59-year-old man and grew into the subclavian vein with extension to the right atrium. An elevated serum level of neuron-specific enolase was also detected. Clinical presentation suggested small cell carcinoma of the lung (Pancoast tumor) with intravenous extension. Eventually, the patient died of respiratory insufficiency. Autopsy revealed a primary tumor in the right shoulder, numerous tumor emboli in the pulmonary arteries, and associated hemorrhagic infarction. Histopathologic features revealed an epithelioid leiomyosarcoma. Furthermore, immunohistochemical and immunoblotting analyses of the tumor demonstrated positive reactions for neuron-specific enolase. We interpreted this peculiar case to be a neuron-specific enolase-producing epithelioid leiomyosarcoma of the soft tissue associated with gross vascular invasion.

Angiography↗
PubMed1997

Cell cycle control with minimal participation of Cdk2 in a murine fibrosarcoma clone cultured in protein-free medium.

The differences in the protein expression of cyclins, cyclin-dependent kinases (cdks), and their inhibitors and cdk kinase activities were examined in serum dependent (SD) and independent (PF) clones of the murine fibrosarcoma cell line, Gc-4. The expression of cyclin A in SD was minimal in contrast to PF. Furthermore, cdk2 kinase activity in PF was remarkably lower than that in SD, yet the G1/S transition in PF appeared normal. PF was also resistant against the selective inhibitor of cdk2, butyrolactone I. These findings suggest that tumor cell proliferation and tumor progression can be promoted by the activation of a molecule(s) downstream of cdk2.

4-Butyrolactone↗