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S Toyooka

Publications and source records attributed to S Toyooka.

18 recordsLinked to original sources
PubMed2005

Aberrant promoter methylation in human DAB2 interactive protein (hDAB2IP) gene in gastrointestinal tumour.

The human DOC-2/DAB2 interactive protein (hDAB2IP) gene is a novel member of the Ras GTPase-activating family and has been demonstrated to be a tumour-suppressor gene inactivated by methylation in several cancers. In this study, we analysed the methylation and expression status of hDAB2IP in gastrointestinal tumours. The promoter region of hDAB2IP was divided into two regions (m2a and m2b) based on our previous report, and the methylation status was determined by bisulphite DNA sequencing in gastric cancer cell lines. The gene expression was semiquantified by real-time RT-PCR, and the results indicated that the m2b promoter region might be an authentic methylation-mediated key regulator of the gene expression. Based on the sequence data, we developed a methylation-specific PCR (MSP) for the m2a and m2b regions and applied it to the samples. Methylation-specific PCR revealed aberrant methylation in the m2a region in eight of 12 gastric cancer cell lines (67%), 16 of 35 gastric cancer tissues (46%) and 29 of 60 colorectal cancer tissues (48%), and in the m2b region in eight of 12 cell lines (67%), 15 of 35 gastric cancer tissues (43%) and 28 of 60 colorectal cancer tissues (47%). On the other hand, seven (12%) and 11 (19%) of 59 gastrointestinal nonmalignant mucosal specimens showed methylation in the m2a and m2b regions, respectively, suggesting that hDAB2IP methylation might play a causative role in carcinogenesis. The 5-aza-2'-deoxycytidine treatment restored the gene expression in the m2b-methylated cell lines, confirming that the methylation caused gene downregulation. We also examined the relationship between hDAB2IP methylation and the clinicopathological features in patients with primary tumours, and determined that methylation in the m2b region was associated with location of the tumour in the stomach. In summary, our results demonstrated that hDAB2IP methylation is frequently present in gastrointestinal tumours and that the resulting gene silencing plays an important role in gastrointestinal carcinogenesis.

Azacitidine↗
PubMed2004

The relationship between aberrant methylation and survival in non-small-cell lung cancers.

The present study examined the relationship between methylation of five genes (p16(INK4a), RASSF1A, APC, RARbeta and CDH13) and patient survival in 351 cases of surgically resected lung cancers. While there was no relationship between the other genes and survival, p16(INK4a) methylation was significantly related to unfavourable prognosis in lung adenocarcinomas.

Adenocarcinoma↗
PubMed2001

Aberrant promoter methylation profile of bladder cancer and its relationship to clinicopathological features.

We investigated the aberrant promoter methylation profile of bladder cancers and correlated the data with clinicopathological findings. The methylation status of 10 genes was determined in 98 surgically resected bladder cancers, and we calculated the median methylation index (MI), a reflection of the methylated fraction of the genes tested. Methylation frequencies of the genes tested in bladder cancers were 36% for CDH1, 35% for RASSF1A and APC, 29% for CDH13, 16% for FHIT, 15% for RAR beta, 11% for GSTP1, 7% for p16(INK4A), 4% for DAPK, and 2% for MGMT. Methylation of four of the individual genes (CDH1, RASSF1A, APC, and CDH13) and the MI were significantly correlated with several parameters of poor prognosis (tumor grade, growth pattern, muscle invasion, tumor stage, and ploidy pattern). Methylation of CDH1, FHIT, and a high MI were associated with shortened survival. CDH1 methylation positive status was independently associated with poor survival in multivariate analyses. Our results suggest that the methylation profile may be a potential new biomarker of risk prediction in bladder cancer.

Adult↗
PubMed2001

Aberrant methylation and simian virus 40 tag sequences in malignant mesothelioma.

Aberrant promoter methylation and resultant silencing of several genes plays an important role in the pathogenesis of many tumor types. We compared the methylation profile of 66 malignant mesotheliomas (MMs) and 40 lung adenocarcinomas using methylation-specific PCR for seven genes frequently methylated in lung cancer. We also compared the methylation frequencies of these genes as well as the methylation index, a reflection of all of the gene frequencies, with the presence of SV40 large T-antigen (Tag) sequences, histological subtype, and patient survival. Our major findings are: (a) with the exception of the RASSF1A promoter of the RASSF1 gene, frequencies of aberrant methylation were significantly lower in MMs than in adenocarcinomas; (b) the frequency of RASSF1A aberrant methylation and the value of the methylation index were significantly higher in SV40 sequence positive MM than in negative MM; and (c) the methylation index was higher in epithelial MM than in sarcomatous/mixed MM. Our results demonstrate a relationship between SV40 and aberrant methylation in MMs.

Adenocarcinoma↗
PubMed2001

Loss of expression and aberrant methylation of the CDH13 (H-cadherin) gene in breast and lung carcinomas.

Expression of some members of the cadherin family is reduced in several human tumors, and CDH13 (H-cadherin), located on chromosome 16q24.2-3, may function as a tumor suppressor gene. In human tumors, loss of expression of many tumor suppressor genes occurs by aberrant promoter region methylation. We examined the methylation status of the CDH13 promoter in breast and lung cancers and correlated it with mRNA expression using methylation-specific PCR and reverse transcription-PCR. Methylation was frequent in primary breast tumors (18 of 55, 33%) and cell lines (7 of 20, 35%). In lung cancers, methylation was present more frequently in non-small cell lung cancer tumors (18 of 42, 43%) and cell lines (15 of 30, 50%) than in small cell lung cancer cell lines (6 of 30, 20%; P = 0.03). Only the methylated or unmethylated forms of the gene were present in most (73 of 80, 91%) tumor cell lines. CDH13 expression was present in 24 of 30 (80%) of nonmethylated tumor lines. All 18 methylated lines tested lacked expression irrespective of whether the unmethylated form was present, confirming biallelic inactivation in methylated lines. Gene expression was restored in all five methylated cell lines tested after treatment with the demethylating agent 5'-aza-2-deoxycytidine. Our results demonstrate frequent aberrant methylation of CDH13 in breast and lung cancers accompanied by loss of gene expression, although expression may occasionally be lost by other mechanisms.

Breast Neoplasms↗
PubMed2001

Epigenetic inactivation of RASSF1A in lung and breast cancers and malignant phenotype suppression.

BACKGROUND: The recently identified RASSF1 locus is located within a 120-kilobase region of chromosome 3p21.3 that frequently undergoes allele loss in lung and breast cancers. We explored the hypothesis that RASSF1 encodes a tumor suppressor gene for lung and breast cancers. METHODS: We assessed expression of two RASSF1 gene products, RASSF1A and RASSF1C, and the methylation status of their respective promoters in 27 non-small-cell lung cancer (NSCLC) cell lines, in 107 resected NSCLCs, in 47 small-cell lung cancer (SCLC) cell lines, in 22 breast cancer cell lines, in 39 resected breast cancers, in 104 nonmalignant lung samples, and in three breast and lung epithelial cultures. We also transfected a lung cancer cell line that lacks RASSF1A expression with vectors containing RASSF1A complementary DNA to determine whether exogenous expression of RASSF1A would affect in vitro growth and in vivo tumorigenicity of this cell line. All statistical tests were two-sided. RESULTS: RASSF1A messenger RNA was expressed in nonmalignant epithelial cultures but not in 100% of the SCLC, in 65% of the NSCLC, or in 60% of the breast cancer lines. By contrast, RASSF1C was expressed in all nonmalignant cell cultures and in nearly all cancer cell lines. RASSF1A promoter hypermethylation was detected in 100% of SCLC, in 63% of NSCLC, in 64% of breast cancer lines, in 30% of primary NSCLCs, and in 49% of primary breast tumors but in none of the nonmalignant lung tissues. RASSF1A promoter hypermethylation in resected NSCLCs was associated with impaired patient survival (P =.046). Exogenous expression of RASSF1A in a cell line lacking expression decreased in vitro colony formation and in vivo tumorigenicity. CONCLUSION: RASSF1A is a potential tumor suppressor gene that undergoes epigenetic inactivation in lung and breast cancers through hypermethylation of its promoter region.

Adult↗
PubMed2001

Stomach is a major source of circulating ghrelin, and feeding state determines plasma ghrelin-like immunoreactivity levels in humans.

Ghrelin, an endogenous ligand for the GH secretagogue receptor, was isolated from rat stomach and is involved in a novel system for regulating GH release. Although previous studies in rodents suggest that ghrelin is also involved in energy homeostasis and that ghrelin secretion is influenced by feeding, little is known about plasma ghrelin in humans. To address this issue, we studied plasma ghrelin-like immunoreactivity levels and elucidated the source of circulating ghrelin and the effects of feeding state on plasma ghrelin-like immunoreactivity levels in humans. The plasma ghrelin-like immunoreactivity concentration in normal humans measured by a specific RIA was 166.0 +/- 10.1 fmol/ml. Northern blot analysis of various human tissues identified ghrelin mRNA found most abundantly in the stomach and plasma ghrelin-like immunoreactivity levels in totally gastrectomized patients were reduced to 35% of those in normal controls. Plasma ghrelin-like immunoreactivity levels were increased by 31% after 12-h fasting and reduced by 22% immediately after habitual feeding. In patients with anorexia nervosa, plasma ghrelin-like immunoreactivity levels were markedly elevated compared with those in normal controls (401.2 +/- 58.4 vs. 192.8 +/- 19.4 fmol/ml) and were negatively correlated with body mass indexes. We conclude that the stomach is a major source of circulating ghrelin and that plasma ghrelin-like immunoreactivity levels reflect acute and chronic feeding states in humans.

Adult↗
PubMed2001

Statistical interferometry based on a fully developed speckle field: an experimental demonstration with noise analysis.

A novel interferometric method named statistical interferometry is proposed and studied. In the method, in contrast to the conventional deterministic interferometry, the complete randomness of the two interfering light fields, i.e., the random interference of the fully developed speckle fields, plays an essential role and is used as a standard of phase in a statistical sense. Preliminary experiments were conducted to verify the validity of the method, followed by a computer simulation. As an experimental result, the accuracy of the measurements of an out-of-plane displacement was confirmed up to lambda/800 by comparison with the heterodyne interferometer. The method has the advantage of simplicity of the optical system required, while at the same time providing high accuracy.

Journal Article↗
PubMed2001

DNA methylation profiles of lung tumors.

Aberrant methylation of CpG islands in promoter regions of tumor cells is one of the major mechanisms for silencing of tumor suppressor genes. We determined the frequency of aberrant promoter methylation of the p16, adenomatous polyposis coli (APC), H-cadherin (CDH13), glutathione S-transferase P1 (GSTP1), O6-methylguanine-DNA-methyltransferase (MGMT), retinoic acid receptor beta-2 (RAR beta), E-cadherin (CDH1), and RAS association domain family 1A (RASSF1A) genes in 198 tumors consisting of small cell lung cancers [SCLCs (n = 43)], non-small cell lung cancers [NSCLCs (n = 115)], and bronchial carcinoids (n = 40). The profile of methylated genes in the two neuroendocrine tumors (SCLC and carcinoids) were very different from that of NSCLC. However, whereas the overall pattern of aberrant methylation of carcinoids was similar to that of SCLC, carcinoids had lower frequencies of methylation for some of the genes tested. There were also significant differences in the methylation profiles between the two major types of NSCLC, adenocarcinoma and squamous cell carcinoma. We performed cluster analysis and found that SCLCs clustered with other SCLCs and carcinoids but not with NSCLCs, whereas the NSCLCs tended to cluster together. Within NSCLCs, adenocarcinomas and squamous cell carcinomas clustered with their respective histological types. Finally, we compared the methylation profiles of SCLC and NSCLC tumors and their respective cell lines (n = 44). In general, methylation frequencies were higher in tumor cell lines, but these differences were seldom significant. Thus, tumor cell lines appear to be suitable models to study aberrant DNA methylation. We conclude that SCLC, carcinoids, squamous cell carcinomas, and adenocarcinomas of the lung have unique profiles of aberrant methylation. Our findings should help us understand differences in the pathogenetic mechanisms of lung cancers.

Adenomatous Polyposis Coli Protein↗
PubMed2000

HD-PTP: A novel protein tyrosine phosphatase gene on human chromosome 3p21.3.

A human cDNA encoding a novel protein tyrosine phosphatase has been isolated. The phosphatase has unique features in its domain structure: a "Zn-hand" domain containing several SH3-binding motifs, a tyrosine phosphatase domain, a C-terminal PEST motif, and an N-terminal domain similar to yeast BRO1, an apoptosis-related mammalian AIP1 and to a RHO-binding protein, Rhophilin. The gene is located at chromosome 3p21.3, an area frequently deleted in many types of cancer, especially within the functionally defined narrow region. The gene may be a human homolog of the rat PTP-TD14 gene reported by others, which can suppress H-ras-mediated transformation. We identified a hemizygous missense mutation in a lung cancer cell line. Thus, the phosphatase gene may be a candidate for one of the tumor suppressor genes located on 3p21.3.

Amino Acid Sequence↗
PubMed1998

[Intrathoracic vagal nerve schwannoma preoperative diagnosis is correct because of clinical and characteristic CT findings--a case report and review of the literature].

A 60-year-old man was operated with the clinical diagnosis of intrathoracic vagal nerve schwannoma because of characteristic CT findings and no symptom of neurofibromatosis. Thoracoscopic surgery was performed and it was confirmed pathologically. Intrathoracic vagal nerve tumor is rare, so preoperative diagnosis seems to be difficult. We review the intrathoracic vagal nerve tumors reported in Japan (52 cases of schwannoma and 9 cases of neurofibroma), and analyzed the tumor location, furthermore, the relationship of neurofibromatosis and schwannoma and neurofibroma on vagal nerve tumor.

Humans↗
PubMed1992

Prophylactic use of ofloxacin in granulocytopenic patients with hematological malignancies during post-remission chemotherapy.

The prophylactic efficacy of ofloxacin (OFLX) therapy was evaluated in 51 granulocytopenic episodes in 22 patients with hematological malignancies during post-remission chemotherapy in a prospective, randomized, controlled trial. Oral administration of OFLX plus amphotericin-B (AMPH) and polymyxin-B (PL) reduced episodes of fever and infection more than did the control regimen with PL and AMPH alone (p less than 0.01), and the reduction in the incidence of infection was evident even in patients showing severe granulocytopenia (p less than 0.01). Furthermore, the first fever after the onset of granulocytopenia in the OFLX regimen developed later than that in the control regimen (p less than 0.05). Clinically, the prophylactic efficacy was 92% for the OFLX regimen and 40% for the control regimen (p less than 0.01). These findings suggest that OFLX is a promising prophylactic agent following post-remission chemotherapy. Patient hemomyelogram findings similar to those of patients with other malignancies may imply that OFLX is widely effective in granulocytopenic patients taking aggressive chemotherapy.

Adolescent↗
PubMed1989

[Asynchronous quadruplicate malignancies: cancer of the stomach, breast and uterus and acute leukemia].

A 71-year-old female was admitted to the Fukui Red Cross Hospital because of abnormal genital bleeding in Feb., 1987. She underwent gastrectomy for early gastric cancer (IIc) 5 years earlier, mastectomy for early breast cancer (stage I) 3 years earlier and radiation therapy (60Co 350rad x 25 days) and chemotherapy (5FU, 200 mg/day, orally) for uterine cancer (stage IIb) 2.5 years earlier. These 3 cancers had quite different histological features one from the other. Laboratory investigation revealed leukocytosis (216, 100/microliters) with 90% blasts. The bone marrow was hyperplastic with 87% blasts. Although 90% of blasts had myeloperoxidase activity, surface marker analysis of the blasts revealed T-cell (CD2, CD3) phenotypes suggesting that the disease was so-called hybrid acute leukemia. She died of intracranial hemorrhage on the 2nd hospital day. An autopsy showed generalized leukemic infiltration and residual uterine cancer without metastasis to other sites. In our country, quadruplicate malignancies including hematological malignancy have been rarely described. The possible pathogenesis of multiple cancers has been discussed.

Acute Disease↗
PubMed1986

Detection of metastatic medullary thyroid cancer with 131I-MIBG scans in Sipple's syndrome.

While 131I-meta-iodobenzyl guanidine (131I-MIBG) scanning has made possible the scintigraphic visualization of pheochromocytoma and neuroblastoma, an accumulation of this agent has recently been reported in medullary thyroid cancer. We present the case of a patient with Sipple's syndrome (multiple endocrine neoplasia type IIa), in whom we were able to identify distant metastases and local invasion of medullary thyroid cancer as well as primary thyroid tumour and right adrenal pheochromocytoma, using 131I-MIBG scans. This case highlights the usefulness of 131I-MIBG in the detection of metastatic medullary thyroid cancer and suggests that this agent may also be of therapeutic use in the treatment of tumours.

3-Iodobenzylguanidine↗