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Biomedical subjects

F Itoh

Publications and source records attributed to F Itoh.

At least 73 records · Page 4Linked to original sources
PubMed1999

Gastric cancers of the microsatellite mutator phenotype display characteristic genetic and clinical features.

BACKGROUND & AIMS: Colon cancer of the microsatellite mutator phenotype (MMP) exhibits significant genotype differences from cancer without the MMP. Twenty-nine MMP-positive gastric cancers were analyzed to clarify if these genotype differences were also associated with distinctive clinicopathologic features. METHODS: Alterations of p53, beta2-microglobulin (beta2M ), hMLH1, and hMSH2 genes were analyzed by using polymerase chain reaction, single-strand conformational polymorphism, sequencing, microallelotyping, hypermethylation assays, and immunostaining. The results were contrasted with mutations in BAX, hMSH3, and hMSH6, genes target for the MMP. RESULTS: Tumors with the MMP had a significantly lower incidence of p53 gene mutations than the other tumors and often contained beta2M gene somatic mutations. Many tumors contained concomitant genetic and epigenetic alterations in DNA mismatch repair genes, hMLH1, hMSH2, hMSH3, and hMSH6. Gastric cancer of the MMP was associated with well/moderate differentiation, distal location, and better survival. CONCLUSIONS: Analysis of somatic alterations in microsatellite sequences and in cancer genes target for the MMP is useful for the classification of groups of gastric cancers with different prognosis. The results further support the concept that (gastric) cancer of the MMP represents a distinctive oncogenic pathway because the mutated cancer genes are usually different from those found in tumors without the MMP.

Adaptor Proteins, Signal Transducing↗
PubMed1999

Messenger RNA expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in human hepatocellular carcinoma.

BACKGROUND: The prognosis of patients with hepatocellular carcinoma is relatively poor because of the high rate of intrahepatic recurrences. We have previously demonstrated an association between enhanced secretion of active matrix metalloproteinases (MMPs; gelatinase A and matrilysin) and early recurrence in hepatocellular carcinoma. The aim of this study was to examine further the relationship between messenger RNA levels of metalloproteinases and their inhibitors and behavior of this carcinoma. METHODS: Messenger RNA expression of gelatinase A, gelatinase B, matrilysin and tissue inhibitor of metalloproteinases (TIMP)-1 and TIMP-2 were analyzed in 30 patients with hepatocellular carcinoma by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). The results were contrasted with the clinicopathological data of the patients. RESULTS: Enhanced mRNA expression of gelatinase A, gelatinase B and matrilysin in tumor was observed in 20, 22 and 19 of 30 patients, respectively. Enhanced mRNA expression of gelatinase A or gelatinase B and of matrilysin showed trends toward presence of capsular invasion (P = 0.078) and intrahepatic metastasis (P = 0.064), respectively. Concomitant overexpression of gelatinase A and matrilysin was associated with portal invasion, intrahepatic metastasis and recurrence within the first postoperative year (P < 0.05). A modest increase of mRNA expression of TIMP-1 and TIMP-2 in tumor was observed in half of the patients, but did not correlate with any clinicopathological features. CONCLUSION: Our results suggest that semiquantitative RT-PCR analysis of MMPs may be helpful in disease management of patients with hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
PubMed1999

Contribution of matrilysin (MMP-7) to the metastatic pathway of human colorectal cancers.

BACKGROUND/AIM: Matrilysin is one of the matrix metalloproteinases that has a critical role in tumour invasion, and is often expressed in gastrointestinal cancers. The aim of this study was to examine the role of matrilysin in metastasis of human colorectal cancers. PATIENTS (SUBJECTS)/METHODS: The relation between matrilysin expression and Dukes's type was investigated immunohistochemically in 83 surgically resected colorectal cancers, including five with liver metastasis. Moreover, the effects of matrilysin on the in vivo invasive and metastatic potential of colon cancer cells transfected with matrilysin cDNA were examined after subcutaneous injection into SCID mice. RESULTS: In 46% of primary and all of metastatic liver tumours, over 10% of cancer cells were stained positively for matrilysin. The expression of matrilysin correlated significantly with the presence of nodal or distant metastases (p<0.05). In addition, matrilysin transfectants formed invasive tumours and multiple liver metastases in SCID mice, without producing any significant difference in the subcutaneous tumour growth from mock transfectants. Casein zymography showed that the invading and metastasised tumours showed conspicuous matrilysin activity, which correlated with the number of metastatic lesions (p<0.001). CONCLUSIONS: Matrilysin showed a correlation with metastasis in a cohort of 83 colorectal cancer patients and marked metastatic potentiation in human colorectal cancer xenografts, indicating that it may play a critical role in the metastatic pathway of colorectal cancers.

Animals↗
PubMed1999

Frequent Bax frameshift mutations in gastric cancer with high but not low microsatellite instability.

Widespread microsatellite instability (MSI) due to the defective DNA mismatch repair underlies the pathogenesis of the majority of hereditary non-polyposis colorectal cancer and a subset of various sporadic malignant tumors. Using 5 microsatellite markers and the criteria of MSI proposed by the National Cancer Institute (NCI) workshop, we analyzed 205 gastric adenocarcinomas for MSI. Based on the number of markers showing instability per tumor, the tumors were divided into three groups; those with two or more of the five markers displaying instability (high MSI, MSI-H), those with one of five markers displaying instability (low MSI, MSI-L), and those with no instability (microsatellite stable, MSS). Among 205 tumors, 30 (15%) were MSI-H, 15 (7%) were MSI-L, and 160 (78%) were MSS. All of the 30 MSI-H tumors demonstrated instability at BAT26, a sensitive marker for the widespread MSI, while none of the 15 MSI-L tumors did. MSI-H tumors were significantly associated with distal location and well or moderate differentiation, but MSI-L tumors were indistinguishable from MSS tumors. Bax frameshift mutations were detected in 60% of the 30 MSI-H tumors, while not in any of the 15 MSI-L tumors. These results suggest that microsatellite analysis using the criteria proposed by the NCI workshop may be appropriate for gastric cancers because it unveils real differences in genotype and phenotype.

Adenocarcinoma↗
PubMed1998

Decreased DCC mRNA expression in human gastric cancers is clinicopathologically significant.

Loss of heterozygosity (LOH) or decreased expression of the deleted in colorectal cancer (DCC) gene, a candidate tumor suppressor gene, has been suggested to correlate with progression in several types of tumors. In human gastric cancers, although DCC LOH has been reported to be frequent in expanding-type tumors, the relation of decreased DCC mRNA expression with clinicopathological features, including metastatic events, remains to be investigated in detail. Therefore, expression levels of DCC mRNA were examined in 52 advanced gastric cancers by the reverse transcription-polymerase chain reaction method combined with Southern blot analysis. Overall, decreased DCC mRNA expression was observed in 27 of the tumors (52%). According to Ming's [Cancer 39, 2475-2485 (1977)] classification, the expanding type showed a significantly higher incidence (71%) than the infiltrative type (17%) (p = 0.0002). Immunohistochemical analysis demonstrated the presence of DCC expression in cancer but not non-cancerous cells in infiltrative-type lesions. An additional follow-up study of tumor recurrence in 42 patients undergoing curative resection implicated decreased DCC expression in metachronous liver metastasis. The results indicate that decreased DCC mRNA expression is closely associated not only with the expanding-type phenotype but also with liver metastasis of gastric cancers. Assessment of this parameter in primary lesions may thus find predictive application.

Adult↗
PubMed1998

Transforming growth factor beta1 induces nuclear export of inhibitory Smad7.

Transforming growth factor beta (TGF-beta) signals from membrane to nucleus through serine/threonine kinase receptors and their downstream effector molecules, termed Smad proteins. Recently, Smad6 and Smad7 were identified, which antagonize TGF-beta family signaling by preventing the activation of signal-transducing Smad complexes. Here we report that Smad7, but not Smad6, inhibits TGF-beta1-induced growth inhibition and the expression of immediate early response genes, including Smad7. Interestingly, in the absence of ligand, Smad7 was found to be predominantly localized in the nucleus, whereas Smad7 accumulated in the cytoplasm upon TGF-beta receptor activation. The latter is in accordance with the physical association of Smad7 with the ligand-activated TGF-beta receptor complex in the cell membrane. Whereas the ectopically expressed C-terminal domain of Smad7 was also exported from the nucleus to the cytoplasm upon TGF-beta challenge, a Smad7 mutant with a small deletion at the C terminus or only the N-terminal domain of Smad7 was localized mainly in the cytoplasm in the absence or presence of ligand. This suggests that an intact Mad homology 2 domain is important for nuclear localization of Smad7. The nuclear localization of Smad7 suggests a functional role distinct from its antagonistic effect in receptor-mediated Smad activation.

Animals↗
PubMed1998

Decreased expression of the metastasis suppressor gene KAI1 in gastric cancer.

KAI1 was immunohistochemically detected in the lower part of fundic glands and intestinal metaplasia in non-cancerous gastric tissues, while only 11.0% (8/73) of cancerous tissues were shown to be positive. The relationship between various clinicopathological characteristics of patients with gastric cancer and KAI1 expression in their tumors was then analyzed to reveal that the incidence of positivity was 16.6% (8/48) of patients with stage Ia-IIIa and 0% (0/25) of patients with stage IIIb-IVb (P < 0.05) and that the incidence of peritoneal or hepatic metastasis tended to be lower in KAI1-positive tumors than in negative ones. These results suggest that decreased KAI1 expression may be related to the progression of gastric cancer.

Adenocarcinoma↗
PubMed1998

Increased invasiveness of MUC1 and cDNA-transfected human gastric cancer MKN74 cells.

MUC1 mucin is an anti-adhesion molecule expressed in a wide variety of tumors. To examine whether MUC1 mucin is involved in tumor invasion, we have prepared MUC1 transfectants using the human gastric cancer cell line MKN74 and performed an in vivo tumor assay by transplanting these into nude mice. Tumor weight at 71 days after s.c. injection of transfectants was measured, showing that the in vivo growth of MUC1 transfectants was increased compared to that of mock transfectants. Furthermore, MUC1-transfectant tumors invaded into the muscle layer, whereas mock-transfectant tumors did not. In vitro invasion, adhesion to extracellular matrix components and phagokinetic track motility were then evaluated to analyze the mechanisms for the in vivo invasiveness of the transfectants. MUC1 transfectants exhibited an increased in vitro invasiveness, decreased binding to laminin, fibronectin, type I collogen and type IV collagen and increased motility. These effects of MUC1 mucin over-expression in MKN74 cells were abolished by the treatment of transfectants with an inhibitor of O-glycan biosynthesis, benzyl-alpha-GalNAc. Our data suggest that MUC1 mucin could be related to the increased invasive ability of MKN74 cells, whereas O-glycan might play an essential role.

Animals↗
PubMed1998

Development of an (X, eX) spectrometer for measuring the energies of the scattered photon and recoil electron.

The design and performance of a new spectrometer for coincidence measurements between the Compton scattered photon and the recoil electron are described. Coincidence measurements give direct information on the three-dimensional electron momentum density (EMD) of condensed matter. The present spectrometer measures energy spectra of both the photon and the electron. The energy spectrum of electrons is measured by a time-of-flight method using single-bunch operation at the Photon Factory Accumulator Ring (PF-AR). The energy resolution obtained for the recoil electron is 190 eV, which is better than that of the photon detector, so that a momentum resolution of the three-dimensional EMD of 0.3 atomic units can be achieved.

Journal Article↗
PubMed1998

High-pressure system for Compton scattering experiments.

High-pressure apparatus for Compton scattering experiments has been developed to study the momentum distribution of conduction electrons in metals and alloys at high pressure. This apparatus was applied to observe the Compton profile of metallic Li under pressure. It was found that the Compton profile at high pressure could be obtained within several hours by using this apparatus and synchrotron radiation. The result on the pressure dependence of the Fermi momentum of Li obtained here is in good agreement with that predicted from the free-electron model.

Journal Article↗
PubMed1998

Infrequent inactivation of DCC gene in replication error-positive colorectal cancers.

Colorectal cancers with and without the replication error (RER) exhibit fundamental differences in genotype and phenotype. While alterations in APC, p53, and K-ras genes have been characterized between RER+ and RER- colorectal cancers, the status of deleted in colorectal carcinomas (DCC) gene has not been yet. Alterations of DCC gene were analyzed in stage-matched two panels of 30 RER+ and 30 RER- colorectal cancers using semiquantitative reverse transcription-PCR and PCR-LOH analyses. Loss or reduction of DCC mRNA expression and allelic loss at the DCC locus were significantly less frequent in RER+ cancers than in RER- cancers. Interestingly, reduced DCC mRNA expression was observed in all 5 RER- cancers with liver metastasis. Our results support the concept that RER+ and RER- colorectal cancers represent different pathways of carcinogenesis and may give a hint for clarifying the specific mechanism of DCC inactivation in RER- colorectal cancers.

Colorectal Neoplasms↗
PubMed1998

Enhancement of reactivity of anti-MUC1 core protein antibody and killing activity of anti-MUC1 cytotoxic T cells by deglycosylation of target tissues or cells.

MUC1 mucin core protein contains an important tumor-associated peptide antigen that can induce cytotoxic T cells (CTLs) in vivo, although this antigen is generally masked by mucin-type glycans. To reveal the precise expression pattern of MUC1 protein in normal and neoplastic gastric tissues, we performed immunohistochemical staining of periodic acid-treated tissue sections with an anti-MUC1 core protein monoclonal antibody (mAb), MUSE11. In non-cancerous tissues, the deep portion of fundic glands and the luminal surface were predominantly immunostained in normal and metaplastic glands, respectively. In cancerous tissues, the incidence of positivity for MUC1 protein varied from 67% to 88%, depending on histological type. This frequent expression of MUC1 protein in cancer tissues after periodic acid treatment suggested that deglycosylation may be of use for exposing the target antigen of anti-MUC1 CTLs. Accordingly, we then examined the effect of benzyl-alpha-GalNAc, an inhibitor of O-glycan biosynthesis, on the expression of MUC1 protein and sensitivity to an anti-MUC1 CTL line, designated TS, in gastric cancer JRST cells. After incubation with benzyl-alpha-GalNAc, the reactivity of mAb MUSE11 with JRST cells and their sensitivity of TS were clearly increased. These findings suggest that deglycosylation may offer an important strategy for enhancing anti-tumor immunity in patients with gastric cancer.

Acetylgalactosamine↗
PubMed1998

Detection of circulating anti-MUC1 mucin core protein antibodies in patients with colorectal cancer.

MUC1 mucin has a unique immunogenic peptide epitope in the extracellular domain, which has been shown to induce humoral and cellular immune response. In this study, we evaluated the pathophysiological significance of circulating anti-MUC1 mucin core protein IgG antibodies (anti-MUC1 antibodies) in colorectal cancer by Western blot analysis and 51Cr release assay. Anti-MUC1 antibodies were detected in 5 of 31 (16.1%) healthy subjects and in 27 of 56 (48.2%) patients with colorectal cancer. The presence of circulating anti-MUC1 antibodies was not significantly correlated with the level of circulating antigen MUSE11 or with other clinicopathological parameters tested. The incidence of positivity for anti-MUC1 antibodies in stage I and II (staged according to the General Rules for Clinical and Pathological Studies on Cancer of the Colon and Rectum of the Japanese Research Society for Cancer of the Colon and Rectum) cancers was 45.5% and 58.8%, respectively, suggesting that positivity for these antibodies may be of use as an adjunct for the diagnosis of colorectal cancer in the early stages in the absence of serious complications such as liver diseases. Because of the epitope similarity, anti-MUC1 antibodies in the serum may function in a manner similar to that of anti-MUC1 peptide monoclonal antibodies (mAbs). We therefore observed antibody-dependent cell mediated cytotoxicity with anti-MUC1 peptide mAb using MUC1 cDNA-transfected colon cancer CHC-Y1 cells as the target. The decreased sensitivity of MUC1 transfectants to effector cells was restored to a level equivalent to that in control cells. These data suggest that the detection of circulating anti-MUC1 antibodies may be a useful adjunct for the early diagnosis and immunological analysis of colorectal cancer.

Adult↗
PubMed1998

Goblet cell carcinoid of the appendix endoscopically diagnosed and examined with p53 immunostaining.

We report a case of a 62-year-old woman with goblet cell carcinoid of the appendix. She was admitted to our hospital in September 1994 after the discovery of liver tumors. After admission, a tumor in the right kidney and multiple tumors in the liver were found. She was diagnosed with renal cell cancer and metastasis to the liver and underwent excision of the kidney and enucleation of the largest liver tumor. Histological examination revealed that the liver tumor was a metastatic carcinoid tumor. As carcinoid tumors have frequently been found in the appendix, endoscopic examination was performed and a lesion was found in the appendix by colonoscopy. As predicted, the biopsy specimen was a carcinoid tumor, and she underwent an appendectomy. Histologically, the tumor was a goblet cell carcinoid. Goblet cell carcinoid is a rather rare neoplasm that has the histologic features of both carcinoids and adenocarcinoma. Forty-two cases of goblet cell carcinoid of the appendix have been reported thus far in Japan. However, few were diagnosed via endoscopic examination before surgical operation. We also carried out an immunohistochemical study with anti p53 antibody on the goblet cell carcinoid tumor of the appendix. Most tumor cells were strongly positive, while in three benign carcinoid tumors investigated simultaneously they were negative. These findings suggest that goblet cell carcinoid has an aggressive phenotype compared with benign carcinoid tumors.

Appendiceal Neoplasms↗
PubMed1998

Expression of sulfated carbohydrate chain and core peptides of mucin detected by monoclonal antibodies in Barrett's esophagus and esophageal adenocarcinoma.

Columnar epithelium-lined esophagus (Barrett's esophagus) is an acquired disorder associated with a high incidence of adenocarcinoma of the lower esophagus. Columnar epithelium resembling intestinal metaplasia (IM) is especially important, since it is considered to be a premalignant condition. The aim of this study was to define the sulfated carbohydrate chain of mucin and its core peptide profile in Barrett's esophagus (BE) and to compare it with the profile in Barrett's adenocarcinoma and lower esophageal adenocarcinoma. The sulfated carbohydrate chain was not expressed in 16 specimens of normal esophageal epithelium, but in BE, it was expressed in 50% (8/16) of the specimens. This chain was detected in 100% (7/7) of esophageal adenocarcinoma specimens, including four cases of Barrett's adenocarcinoma. These data suggest that the sulfated carbohydrate chain may be associated with malignant phenotype of the esophagus. MUC1 core peptide was positive in 87% (13/15) of BE specimens and in 29% (2/7) of the esophageal adenocarcinoma specimens. MUC2 core peptide was present in 57% (8/14) and 43% (3/7) of these specimens, respectively. These data suggest that Barrett's epithelium, which is similar to IM, but not normal esophageal epithelium, expresses the sulfated sugar chain which is known to be present in gastric IM and colonic mucosa. However, there was no significant correlation between the expression of the sulfated sugar chain and the expression of either mucin core peptide MUC1 or MUC2. Thus, this carbohydrate chain may be expressed on as yet unidentified core proteins, other than MUC1 or MUC2 core peptide, in BE and esophageal adenocarcinoma. Identification of these proteins may be very important in helping to detect premalignant status in BE.

Adenocarcinoma↗
PubMed1998

Heat influences on plasma insulin and glucagon in response to secretogogues in non-lactating dairy cows.

Four non-lactating cows were offered a maintenance diet of hay wafer and a commercial concentrate. They were housed in a thermoneutral (TN; 20 degrees C) and then a hot (30 degrees C) environment in an artificial climate chamber. Glucose, arginine, butyrate, and insulin were administered through one jugular catheter, and from a catheter on the other side venous blood was collected. The peak increments in plasma insulin after the glucose and butyrate administrations were lower during heat exposure. The response of insulin after arginine injection was smaller in the hot compared with the thermoneutral environment; however, arginine injection resulted in a significantly higher secretion of glucagon in the hot environment. The response area of insulin after the insulin injection was smaller in the hot environment; however, insulin clearance rate was not changed. It is concluded that in non-lactating cows, insulin release is probably lower during heat exposure. With respect to plasma glucose during heat exposure, the lower basal values, lower concentrations after the end of the glucose infusion, and delayed recovery to basal values after the butyrate and insulin administrations observed, may indicate lower gluconeogenesis and glycogenolysis in the hot environment.

Animals↗