Biomedical subjects

M Ohira

Publications and source records attributed to M Ohira.

At least 37 records · Page 2Linked to original sources

PubMed2001

Apoptosis and thymidylate synthase inductions by 5-fluorouracil in gastric cancer cells with or without p53 mutation.

We studied apoptosis and thymidylate synthase (TS) inductions by 5-fluorouracil (5-FU) in gastric cancer cells with wild-type p53 (MKN-45 and MKN-74) and with mutated p53 (MKN-28 and KATO-III). Apoptotic inductions in MKN-45 and MKN-74 were stronger than those in MKN-28 and KATO-III, suggesting that wild-type p53 may contribute to the induction of apoptosis. After continuous exposure to 0.1 microg/ml of 5-FU for 96 h, no TS induction was obtained in KATO-III, while approximately twice the amount of TS was observed compared to non-treatment cells in MKN-45, MKN-74, and MKN-28. The results of immunohistochemical staining for TS and p53 showed no relation between these two protein expressions in endoscopic biopsy specimens of 25 patients with advanced gastric cancer. These results indicated that p53 status may not play a pivotal role in regulating TS expression. We found no significantly different effects of 5-FU between intermittent (repeat of 24-h continuous infusion and 24-h drug-free) and continuous treatments in either MKN-28 or stem cells (CD34+ hematopoietic progenitor cells) when the same area under the time-concentration curve of 5-FU was administered. The TS induction in MKN-28 cells by intermittent treatment was significantly higher than that by continuous treatment; however, most TSs in both types of 5-FU treatment cells were of the inactive form, i.e., TS bound to FdUMP, a 5-FU metabolite. Therefore, neither intermittent nor continuous treatment appears to induce 5-FU resistance related to the level of increment free TS. In conclusion, our observations suggested that p53 mutation may be associated with apoptotic induction by 5-FU; however, p53 status may not strongly affect TS induction by 5-FU. Intermittent treatment can be replaced with continuous treatment without causing 5-FU resistance.

Antimetabolites, Antineoplastic↗

PubMed2001

TGF-beta1 promotes liver metastasis of pancreatic cancer by modulating the capacity of cellular invasion.

We investigated the effect of TGF-beta1 on liver metastasis of pancreatic cancer using surgical specimens of pancreatic cancer and human pancreatic cancer cell lines Capan-2 and SW1990. Immunostaining of TGF-beta1 showed that TGF-beta1 positivity was significantly related to venous invasion and tumor staging, and also relatively associated with liver metastasis. Cellular invasion and protease production of MMP-2 and u-PA, and in vivo liver metastasis were significantly enhanced after treatment of cells with TGF-beta1. These findings suggest that TGF-beta1 might play an important role in enhancing liver metastasis of pancreatic cancer.

Adenocarcinoma↗

PubMed2001

Establishment of a new scirrhous gastric cancer cell line with loss of heterozygosity at E-cadherin locus.

Scirrhous gastric carcinoma, characterized by carcinoma cell proliferation and infiltration with extensive fibrosis in the stroma, frequently causes peritoneal metastasis. We describe here a newly established cell line, OCUM-6, derived from ascites effusion of a scirrhous gastric cancer patient. The cells are floating and round shape, similar to other scirrhous gastric carcinoma cell lines previously reported. Histologic findings of xenografted tumor obtained from OCUM-6 cells showed medullary growth with a poorly differentiated adenocarcinoma containing signet ring cells. LOH at E-cadherin locus 16q22 was observed in the OCUM-6 cells. LOH at E-cadherin locus might be closely associated with histologic findings and metastatic process of scirrhous gastric cancer. The scirrhous gastric cancer cell line, OCUM-6, may be useful for investigation of the mechanisms of peritoneal dissemination and carcinogenesis.

Adenocarcinoma, Scirrhous↗

PubMed2001

A candidate tumor suppressor locus for scirrhous gastric cancer at chromosome 18q 12.2.

We investigated LOH on 5q, 16q, 17p, 17q, and 18q in scirrhous gastric cancer and identified the chromosomal locus that is frequently deleted in scirrhous gastric cancer. LOH frequency on 18q of scirrhous gastric cancer was found to be significantly higher than that of the other types of advanced gastric cancer, while no significant difference between LOH at 5q, 16q, 17p and 17q was found. Eight microsatellite markers on chromosome 18q were additionally examined in scirrhous gastric cancer. The highest rates of LOH were observed at the D18S34 locus which is located at 18q12.2. These findings suggest that the D18S34 locus might be a novel candidate tumor suppressor locus in scirrhous gastric carcinoma.

Adenocarcinoma, Scirrhous↗

PubMed2001

Effect of a matrix metalloproteinase inhibitor on a lymph node metastatic model of gastric cancer cells passaged by orthotopic implantation.

Lymph node metastasis is the most frequent type of tumor recurrence and is known to be one reason for the poor prognosis in patients with digestive cancer. However, the mechanisms of lymph node metastasis are not clearly understood and a metastatic model will be useful for elucidating factors associated with lymph node metastases. In this study, we investigated the effect of R-94138, a matrix metalloproteinase (MMP) inhibitor, on the lymphnodal metastatic ability of gastric cancer cells using an in vivo orthotopic implantation model in nude mice. Injection of a gastric cancer cell line, MKN-45, into the gastric wall resulted in lymph node metastasis 8 weeks after inoculation. The number of lymph node metastases and the amount of body weight loss significantly decreased by intraperitoneal administration of R-94138. Histologically, lymphatic invasion of cancer cells was found in primary gastric tumors of control mice with lymph node metastasis. However, no lymphatic invasion was observed in the gastric wall of R-94138-treated mice without lymph node metastasis. These findings suggested that the MMP inhibitor, R-94138, could be used in adjunctive therapy for lymph node metastasis in gastric carcinoma.

Acetamides↗

PubMed2000

Identification and characterization of a 500-kb homozygously deleted region at 1p36.2-p36.3 in a neuroblastoma cell line.

Loss of heterozygosity of the distal region of chromosome 1p where tumor suppressor gene(s) might harbor is frequently observed in many human cancers including neuroblastoma (NBL) with MYCN amplification and poor prognosis. We have identified for the first time a homozygously deleted region at the marker D1S244 within the smallest region of overlap at 1p36.2-p36.3 in two NBL cell lines, NB-1 and NB-C201 (MASS-NB-SCH1), although our genotyping has suggested the possibility that both lines are derived from the same origin. The 800-kb PAC contig covering the entire region of homozygous deletion was made and partially sequenced (about 60%). The estimated length of the deleted region was 500 kb. We have, thus far, identified six genes within the region which include three known genes (DFF45, PGD, and CORT) as well as three other genes which have been reported during processing our present project for the last 3(1/2) years (HDNB1/UFD2, KIAA0591F/KIF1B-beta, and PEX14). They include the genes related to apoptosis, glucose metabolism, ubiquitin-proteasome pathway, a neuronal microtubule-associated motor molecule and biogenesis of peroxisome. At least three genes (HDNB1/UFD2, KIAA0591F/KIF1B-beta, and PEX14) were differentially expressed at high levels in favorable and at low levels in unfavorable subsets of primary neuroblastoma. Since the 1p distal region is reported to be imprinted, those differentially expressed genes could be the new members of the candidate NBL suppressor, although RT-PCR-SSCP analysis has demonstrated infrequent mutation of the genes so far identified. Full-sequencing and gene prediction for the region of homozygous deletion would elucidate more detailed structure of this region and might lead to discovery of additional candidate genes. Oncogene (2000) 19, 4302 - 4307

Carrier Proteins↗

PubMed2000

Development of a new cyano-bonded column for high-performance liquid chromatography.

A unique cyano-bonded column for high-performance liquid chromatography was developed by chemically bonding cyanopropyl groups to the silica gel support, and its chromatographic performance was described. Eight cyanopropyl-bonded silica gels were prepared under different conditions. These packing materials were packed into a stainless steel column, the chromatographic properties and durability of which were investigated in both normal- and reversed-phase partition modes. The separating selectivity and the durability of cyanopropyl-bonded silica (CN) columns were dependent on the preparation conditions. Particularly, the relationship between the density of cyanopropyl groups on the surface of the silica gel and the irreversible adsorption of basic compounds was examined. Also, the experimental results indicated that endcapping resulted in the poor separating selectivity and durability of the CN columns.

Chromatography, High Pressure Liquid↗

PubMed2000

Characterization of an avidin-bonded column for direct injection in reversed-phase high-performance liquid chromatography.

A denatured avidin-bonded column was suitable for use in the reversed-phase HPLC and complete recovery of serum protein over a wide range of pH. Retention property of the denatured avidin-bonded column was very nearly to a non-denatured avidin-bonded column already reported and, however, showed very high stability to organic solvent. A performance of the denatured avidin-bonded column was maintained even if 500 continuous injections of human serum (total 10 ml).

Avidin↗

PubMed2000

High expression of Survivin, mapped to 17q25, is significantly associated with poor prognostic factors and promotes cell survival in human neuroblastoma.

Survivin (SVV) is a family member of inhibitor of apoptosis proteins (IAPs) and its expression is cell cycle regulated. The gene is mapped to chromosome 17q25, the region of which is frequently gained in advanced stages of neuroblastoma (NBL). However, the role of SVV in NBL is poorly understood. Here we studied the clinical and biological role of SVV in NBL. A 1.9 kb SVV transcript was expressed in all of 9 NBL cell lines at higher levels than those in adult cancer cell lines. In 34 primary NBLs, high levels of SVV expression was significantly associated with age greater than 12 months (two sample t-test: P= 0.0003), advanced stages (P = 0.0136), sporadic tumors (P= 0.0027) and low levels of TrkA expression (P = 0.0030). In NBL cell lines, SVV mRNA expression was dramatically down-regulated in CHP134 and IMR32 cells undergoing apoptosis after treatment with all-trans retinoic acid (RA) or serum deprivation. It was only moderately decreased in cells (SH-SY5Y and CHP901) undergoing RA-induced differentiation. On the other hand, in proliferating NBL cells or RA-treated SK-N-AS line which is refractory to RA, the SVV mRNA remained at steady state levels or rather up-regulated. Furthermore, transfection of SVV into CHP134 cells induced remarkable inhibition of the RA-induced apoptosis. Collectively, our results suggest that high expression of SVV is a strong prognostic indicator for the advanced stage neuroblastomas, and that it could be one of the candidate genes for the 17q gain.

Apoptosis↗

PubMed2000

Identification of the homozygously deleted region at chromosome 1p36.2 in human neuroblastoma.

BACKGROUND: We have identified for the first time a homozygously deleted region within the smallest region of overlap at 1p36.2-3 in two neuroblastoma cell lines. PROCEDURE: The 800-kb PAC contig covering the entire homozygously deleted region was made and sequenced. To date, approximately 70% of sequencing has been accomplished, and the estimated length of the deleted region was 500 kb. RESULTS: Currently, we have found six genes within the region, which include three known genes as well as three other genes that have been reported during processing of our present project for the last 3(1/2) years. We report here the results of expression and mutation analyses of those genes. CONCLUSIONS: Full sequencing for the region of homozygous deletion as well as further analyses of the genes mapped within the region may reveal whether or not there is a neuroblastoma suppressor gene as proposed by the Knudson's two-hit hypothesis.

Child, Preschool↗

PubMed2000

Analysis of loss of heterozygosity at 16p12-p13 (familial neuroblastoma locus) in 470 neuroblastomas including both sporadic and mass screening tumors.

BACKGROUND: Neuroblastoma (NBL) in children usually occurs in a sporadic form. However, it rarely occurs in families. Recently, the familial neuroblastoma (FNB) locus has been mapped to 16p12-p13 by linkage analysis. PROCEDURE: Here we show the result of loss of heterozygosity in the region spanning 16p12-p13 (D16S406-D16S409, 46 cM) in 470 NBLs including both sporadic and mass screening cases. RESULTS: Allelic loss was found in 61(13%) tumors. Deletion of 16p was associated with mass screening tumor (P = 0.035) and <1 year of age at diagnosis (P = 0.048). We found two commonly deleted regions: the sizes of the region were approximately 2 cM and approximately 6 cM. CONCLUSIONS: Our data suggested that allelic loss of 16p was common in favorable NBLs, and there may be at least two candidate loci within the region of FNB.

Child↗

PubMed2000

Hunting the subset-specific genes of neuroblastoma: expression profiling and differential screening of the full-length-enriched oligo-capping cDNA libraries.

BACKGROUND: Neuroblastoma (NBL) has a distinct nature in different prognostic subgroups. PROCEDURE: To understand the molecular mechanism of NBL's genesis and biology as well as that of the neural crest development, we constructed full-length-enriched cDNA libraries by an oligo-capping method from two different subsets of primary NBL, one with favorable biology and the other with MYCN amplification. RESULTS: Sequencing analysis of these libraries revealed that the expression profile was markedly different between both subsets. To identify the genes differentially expressed between the subsets, semi-quantitative RT-PCR analyses are proceeding. CONCLUSION: So far, 54 transcripts have been found to be expressed at high levels in favorable NBLs, and significantly at low levels in unfavorable NBLs.

Gene Expression Regulation, Neoplastic↗

PubMed2000

Association between favorable neuroblastoma and high expression of the novel metalloproteinase gene, nbla3145/XCE, cloned by differential screening of the full-length-enriched oligo-capping neuroblastoma cDNA libraries.

BACKGROUND: The biology of neuroblastoma (NBL) is at least partly regulated by neurotrophic factors and their receptors. PROCEDURE: To identify novel NBL-related genes that affect growth, differentiation, and programmed cell death of the tumor, we constructed full-length-enriched cDNA libraries by oligo-capping method. RESULTS: Semi-quantitative and quantitative real-time RT-PCR showed that the nbla3145 gene was significantly highly expressed in favorable subset of NBL. The nucleo-tide sequence of nbla3145 revealed that it was a novel member of metalloproteinase, endothelin-converting enzyme, and was the same gene recently reported as XCE. We also cloned nbla3145beta which was a novel truncated form of nbla3145 (or nbla3145alpha). CONCLUSIONS: Our results suggested that nbla3145/XCE plays an important role in regulating growth and differentiation of NBL.

Gene Expression Regulation, Neoplastic↗

PubMed2000

Molecular cloning and expression analysis of the human DA41 gene and its mapping to chromosome 9q21.2-q21.3.

DA41 was previously identified as one of the DAN-binding proteins, via a yeast-based two-hybrid screening strategy. In the present study, we cloned a human homolog of DA41 cDNA. Structural analysis revealed that human DA41 cDNA consisted of 2,861 nucleotides in length and encoded a protein of 589 amino acids, with a predicted molecular mass of 62.4kDa. Human DA41 exhibited an 86% amino acid sequence identity to rat DA41, indicating the evolutionarily conserved structure and function of DA41. A database search for DA41-related protein(s) identified mouse PLIC-1, PLIC-2, frog XDRP1, and yeast DSK2. DA41 and each DA41-related protein contain a ubiquitin-like domain in their amino-terminal regions. DA41 was expressed ubiquitously in adult human tissues, with relatively higher levels in pituitary gland, adrenal gland, kidney, thymus, and placenta. Fluorescence in situ hybridization (FISH) revealed that DA41 was mapped to human chromosome 9q21.2-q21.3, a position overlapping the candidate tumor suppressor locus for bladder cancer.

Adaptor Proteins, Signal Transducing↗

PubMed2000

Long-term follow-up of childhood acute lymphoblastic leukemia in Tokyo Children's Cancer Study Group 1981-1995.

The objectives were as follows: Firstly, to estimate the overall probability of event-free survival (EFS) and isolated CNS relapse in the studies for children with acute lymphoblastic leukemia (ALL) during the 1980s and 1990s. Secondly, to report the EFS according to presenting features and lineage. Thirdly, to evaluate the treatment results re-classified by the risks of NCI criteria. Four consecutive protocol studies were performed in the Tokyo Children's Cancer Study Group: L81-10 protocol (1981-1984, 189 patients), L84-11 (1984-1989, 484 patents), L89-12 (1989-1992, 418 patients) and L92-13 (1992-1995, 347 patients). Overall EFS at 5 years in each protocol was 56.5 +/- 3.8(1 s.e.)%, 71.0 +/- 2.1%, 67.8 +/- 2.3%, and 63.4 +/- 2.7%, respectively. The cumulative isolated CNS relapse rate at 5 years was 8.1 +/- 2.1%, 3.5 +/- 0.9%, 3.6 +/- 1.0%, 1.0 +/- 0.6. The EFS in SR/HR (standard risk/high risk) according to the NCI criteria in B-precursor ALL at 5 years was 61.9 +/- 4.3%/41.4 +/- 7.4% (lineage was not confirmed.), 72.5 +/- 2.6%/63.4 +/- 5.0%, 77.4 +/- 2.7%/56.3 +/- 4.7%, and 67.8 +/- 3.4%/56.7 +/- 5.4% in each protocol. Also EFSs according to NCI SR/HR at 5 years of T-ALL in protocols L84-11, L89-12 and L92-13 were 55.6 +/- 16.6%/60.9 +/- 10.1%, 72.7 +/- 13.4%/51.6 +/- 9.1%, and 77.1 +/- 14.4%/53.6/10.1%, respectively. The truncation of maintenance therapy to 6 months resulted in a decreased EFS in L92-13, particularly due to an increase of bone marrow relapse after cessation of therapy in SR and HR. The NCI risk criteria work properly even in the patients treated by different intensities, so that it makes the comparison possible among the patients in various groups. The overall EFSs in childhood ALL improved in 1980s, but it seemed stable or decreased in 1990s. The short maintenance therapy resulted in poor outcome in SR on the L92-13 protocol. Many of these late relapsers were effectively rescued and overall survival remained at a high level. The proportion of patients who received cranial irradiation reduced without any increase of the CNS events.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2000

Identification of the full-length KIAA0591 gene encoding a novel kinesin-related protein which is mapped to the neuroblastoma suppressor gene locus at 1p36.2.

The distal region of a short arm of chromosome 1p is frequently deleted in many human cancers including neuroblastoma (NBL), in which it has been narrowed down to the smallest region of overlap between D1S244 and D1S214 (approximately 7 cM). During the search for the candidate tumor suppressor genes mapped within the region, we found the KIAA0591 gene which encoded a new human kinesin-related protein with a homology to human axonal transporter of synaptic vesicles (ATSV). The kinesin is an intracellular motor protein and often associated with neuronal differentiation and survival. Here we identified a complete open reading frame of the KIAA0591 gene by screening a cDNA library derived from human substantia nigra. The KIAA0591 protein contains a possible pleckstrin homology (PH) domain at its carboxy-terminus. However, it did not possess a force-generating motor domain which is well conserved among kinesin superfamily members (KIFs). Northern blot analysis demonstrated that KIAA0591 mRNA was preferentially expressed in both adult and fetal brains, kidney, skeletal muscle and pancreas. KIAA0591 was expressed in favorable NBLs at higher levels than in unfavorable NBLs, although RT-PCR SSCP analysis showed no mutation within the coding region of the KIAA0591 gene, when 8 neuroblastoma tissues and 15 neuroblastoma-derived cell lines were examined. Thus, the full-length KIAA0591 gene may be a novel member of human KIF superfamily which lacks motor domain and might function as a tumor suppressor in an epigenetic but not a classic Knudson's manner.

Amino Acid Sequence↗

PubMed2000

Contribution of angiogenesis to the progression of colon cancer: possible inhibitory effect of angiogenesis inhibitor TNP-470 on tumor growth and hepatic metastasis.

The contribution of angiogenesis to tumor growth and hepatic metastasis of colorectal cancer was investigated by means of immunohistochemical study and in vitro and in vivo experiments. Colorectal cancer specimens from 30 patients with hepatic metastasis and 39 patients without hepatic metastasis were studied by staining with antibodies against factor VIII-related antigen. Microvessel count in patients with liver metastasis was significantly higher than in those without liver metastasis (p<0.005). The effect of TNP-470 was evaluated with in vitro and in vivo experiments using human colon cancer cell line, LM and the highly hepatic metastasis cell line, LM-H5. The effect of TNP-470 on the proliferation of the cancer cells and human umbilical vein endothelial cells (HUVECs) was examined. TNP-470 inhibited more sensitively the proliferation of HUVECs than cancer cells in vitro. IC50 was approximately 3 pg/ml in HUVECs and approximately 2 microg/ml in cancer cells. The effect of TNP-470 on the growth of xenografts and liver metastases by LM-H5 in nude mice was examined. TNP-470 (30 mg/kg) was administered by subcutaneous injection every third day for 4 weeks. TNP-470 inhibited both the growth of xenograft and the hepatic metastasis. The number of metastatic foci in the liver was 78.2+/-30.1 in the control group and 20.6+/-16.5 in the treated group. These results suggest that TNP-470 is a potent agent to inhibit tumor growth and hepatic metastasis of colon cancer.

Adult↗

PubMed2000

[Hepatic arterial infusion chemotherapy for unresectable liver metastasis of gastrointestinal cancers].

Thirty-two patients with colorectal cancer, eleven with gastric cancer and two with pancreatic cancer were treated by hepatic arterial infusion chemotherapy from March 1988 to December 1999. A single administration of 5-FU, MMC and epirubicin (FAM group), or intermittent continuous infusion of 5-FU 500 mg/2 h (5-FU continuous group) was used for each patient once a week. Overall survival rates were not significantly different between the gastric and colorectal cancer patients. In patients with colorectal cancer, there was a significant prolongation in overall survival for the response group. With gastric cancer, however, there was no significant difference. For both of the two patients with pancreatic cancer, although they were responsive to the therapy, there was no prolongation of survival. In conclusion, intermittent continuous infusion was more effective for the patients with colorectal cancer. In patients with gastric and pancreatic cancer, hepatic intra-arterial infusion could control the progression of liver metastasis.

Antineoplastic Combined Chemotherapy Protocols↗