Biomedical subjects

Shigeo Nakamura

Publications and source records attributed to Shigeo Nakamura.

At least 55 records · Page 3Linked to original sources

PubMed2005

Identification of CCND3 and BYSL as candidate targets for the 6p21 amplification in diffuse large B-cell lymphoma.

PURPOSE: Increases in gene dosage through DNA amplification represents a common feature of many tumors and can result in the up-regulation of tumor-promoting genes. Our recent genome-wide, array-based comparative genomic hybridization analysis of 66 cases of diffuse large B-cell lymphoma found that genomic gain of 6p21 was observed in as many as 17 cases, including 14 cases with low-level copy number gain and three cases with high-level copy number gains (amplifications). EXPERIMENTAL DESIGN AND RESULTS: To identify the target gene(s) for 6p21 amplification, we constructed a detailed amplicon map at the region of genomic amplification with the aid of high-resolution contig array-based comparative genomic hybridization glass slides, consisting of contiguously ordered bacterial artificial chromosome/P1-derived artificial chromosome clones covering 3 Mb throughout the 6p21 amplification region. Alignment of the amplifications identified a minimally overlapping 800 kb segment containing 15 genes. Quantitative expression analysis of the genes from both patient samples and the SUDHL9 cell line revealed that CCND3 and BYSL (1.9 kb telomeric to the CCND3 gene locus) are the targets of 6p21 genomic gain/amplification. CONCLUSIONS: Although it is known that t(6;14)(p21;q32) induces aberrant overexpression of CCND3 in B-cell malignancies, we were able to show that CCND3, which encodes the cyclin D family member protein that controls the G1-S phase of cell cycle regulation, can also be a target of genomic gain/amplification. Overexpression of CCND3 through genomic amplification is likely to lead to aberrant cell cycle control, although the precise biological role of BYSL with respect to tumorigenesis remains to be determined.

Blotting, Northern↗

PubMed2005

Overexpression of caspase recruitment domain (CARD) membrane-associated guanylate kinase 1 (CARMA1) and CARD9 in primary gastric B-cell lymphoma.

BACKGROUND: Although caspase recruitment domain (CARD) membrane-associated guanylate kinase (MAGUK) protein 1 (CARMA1) and CARD9 play important roles in lymphocyte activation, the significance of CARMA1 and CARD9 in the pathogenesis of gastric mucosa-associated lymphoid tissue (MALT) lymphoma remains to be elucidated. METHODS: By using reverse transcription-polymerase chain reaction analysis, the expression levels of mRNA of CARMA1, CARD9, Bcl10, and the apoptosis inhibitor 2 (API2)-MALT1 chimeric transcript were determined in tissue specimens from 65 patients with primary gastric B-cell lymphoma (43 patients with low-grade MALT lymphoma, 16 patients with MALT lymphoma plus diffuse large B-cell lymphoma [DLBL], and 6 patients with DLBL without MALT lymphoma) and in tissue specimens from 18 patients with chronic gastritis. The expression levels of CARMA1 and BCL10 were examined immunohistochemically in 30 patients with lymphoma. RESULTS: CARMA1 mRNA was detected in 55% of lymphoma patients but in only 17% of chronic gastritis patients. The positive rates for CARD9, Bcl10, and API2-MALT1 chimeric transcript in the lymphoma patients were 48%, 98%, and 8%, respectively, whereas the 3 molecules were not detected in any specimens from patients with chronic gastritis. The expression of CARMA1 and CARD9 was frequent in the Helicobacter pylori-negative patients (100% and 86%, respectively), in the API2-MALT1 chimeric transcript-positive patients (100% and 100%, respectively), and in the specimens from patients who did not respond to H. pylori eradication (76% and 71%, respectively). In addition, CARMA1 expression was positive more frequently in patients of DLBL without MALT lymphoma (100%) than in patients of MALT lymphoma (51%). CARMA1 protein expression was correlated significantly with the expression of CARMA1 mRNA and also with the expression of nuclear BCL10. CONCLUSIONS: The overexpression of CARMA1 and CARD9 presumably is associated with the development or progression of gastric B-cell lymphoma, especially among patients who have disease in which the pathogenesis is not related to H. pylori.

Adaptor Proteins, Signal Transducing↗

PubMed2005

Intravascular large T-cell lymphoma: a case report of CD30-positive and ALK-negative anaplastic type with cytotoxic molecule expression.

We reported a case of intravascular T-cell lymphoma (T-IVL) with anaplastic large cell morphology, the hemophagocytic syndrome, and an aggressive clinical course. Phenotypic analysis of the tumor cells revealed CD2+, CD3-, CD4+, CD5-, CD8-, CD30+, CD56-, T-cell receptor alpha/beta-, ALK-, TIA1+, granzyme B+, and perforin+. No association with Epstein-Barr virus was found by in situ hybridization. A review revealed that 25 cases of T-IVL have been reported in the available literature, only two of which were of CD30+ anaplastic large cell or cytotoxic T-cell type. The findings in the present case may highlight the unique clinicopathologic aspects of a subset of CD30-positive T-IVLs with an ALK-negative cytotoxic phenotype.

Aged↗

PubMed2005

Antidepressant-like effect of coadministration of sulpiride and fluvoxamine in mice.

We have recently reported that coadministration of sulpiride, an antipsychotic drug, and fluvoxamine, a selective serotonin (5-HT) reuptake inhibitor, selectively increases in vivo dopamine release in the prefrontal cortex. This study examined the effects of coadministration of these drugs on duration of immobility in the tail suspension test using mice. Neither sulpiride (3 or 10 mg/kg) nor fluvoxamine (10 or 20 mg/kg) alone affected immobility time, whereas coadministration significantly reduced immobility time. WAY 100635, a 5-HT(1A) receptor antagonist, did not affect the effects of sulpiride and fluvoxamine coadministration, but reduced immobility time in combination with fluvoxamine (20 mg/kg). A high dose of fluvoxamine alone (60 mg/kg) also reduced immobility time. These results suggest that the antidepressant-like effects of fluvoxamine in combination with sulpiride or WAY 100635 in the tail suspension test are mediated by the activation of dopamine or 5-HT systems, respectively.

Animals↗

PubMed2005

Blastic natural killer cell lymphoma/leukemia (CD56-positive blastic tumor): prognostication and categorization according to anatomic sites of involvement.

BACKGROUND: Blastic natural killer (NK) cell lymphoma/leukemia (BNKL) is an immature CD56-positive neoplasm, which was recognized recently and characterized by systemic proliferation of tumor cells including skin, lymph node, and bone marrow. METHODS: The current study analyzed 47 patients with BNKL (27 had leukemias and 20 had lymphomas). Patient data were collected for the survey of the NK-Cell Tumor Study Group. RESULTS: There were 33 males and 14 females, with a median age of 53 years (range, 3 months to 89 years). There were few clinicopathologic differences between the leukemia and lymphoma types. Cutaneous involvement was noted at diagnosis in 28 patients, who presented a tendency for older age of onset (median: 56 vs. 46 years, P = 0.11) than patients with noncutaneous BNKL. Cutaneous BNKL showed less frequent mediastinal involvement (4% vs. 53%, P = 0.0002) and less severe thrombocytopenia (P =0 .03). Phenotypic characteristics were also different, with cutaneous BNKL favoring CD4 and HLA-DR expression, and noncutaneous BNKL favoring CD16 and CD34 expression. Both groups responded well to chemotherapy for lymphoid malignancies, but disease recurrence was frequent. The prognosis of patients with noncutaneous BNKL was significantly poorer than that of patients with cutaneous BNKL (median survival: 15 vs. 25 months, P = 0.02). Multivariate analysis confirmed that cutaneous involvement was a significant and independent prognostic factor for BNKL, as were age of onset and leukocyte count. CONCLUSIONS: These findings suggested that BNKL is a heterogeneous disease and contains at least two subtypes. Although further investigations are needed to settle a marker for distinction, the presence of cutaneous involvement is a useful prognostic factor.

Adolescent↗

PubMed2005

Preparation and antioxidant activity of alpha-pyridoin and its derivatives.

Focusing on alpha-pyridoin (1, 1,2-di(2-pyridyl)-1,2-ethenediol) as the lead compound of the novel antioxidative enediol, we synthesized 5,5'- or 6,6'-bis-substituted derivatives of 1 from disubstituted pyridines. The antioxidant activity of 1 and its synthetic derivatives 2-7 was evaluated by DPPH (1,1-diphenyl-2-picrylhydrazyl radical) scavenging assay and inhibition of lipid peroxidation. In the DPPH assay, 1 exhibited an activity stronger than that of ascorbic acid, and 5,5'-dimethyl-(5) or 5,5'-dimethoxy-substituted derivatives (6) exhibited more potent activity than 1. The DPPH scavenging activities of alpha-pyridoins were correlated with their oxidation potential and thus the electron density of enediol. 5 and 6 effectively inhibited lipid peroxidation in the rat liver microsome/tert-butyl hydroperoxide system. Therefore, 5 and 6 serve as good candidates for a pharmacologically useful enediol antioxidant.

Aldehydes↗

PubMed2005

Long-term clinical outcome of Helicobacter pylori eradication for gastric mucosa-associated lymphoid tissue lymphoma with a reference to second-line treatment.

BACKGROUND: The goals of the current study were to elucidate the long-term outcome of Helicobacter pylori eradication therapy for gastric mucosa-associated lymphoid tissue (MALT) lymphoma and to clarify the therapeutic efficacy of stomach-conserving treatments for patients not responding to eradication therapy. METHODS: Ninety-six patients with gastric MALT lymphoma, including 17 patients with areas of diffuse large B-cell lymphoma, were treated by H. pylori eradication. Patients not responding to eradication therapy underwent either a gastrectomy, multiagent chemotherapy, oral monochemotherapy (OMC), or radiotherapy (RT). Predictive factors for the response to eradication therapy, overall survival (OS), and event-free survival (EFS) were determined by the Kaplan-Meier analysis with the log-rank test. The efficacy of second-line treatment was compared between OMC and RT. RESULTS: After eradication therapy, 62 (65%) patients achieved complete disease remission (CR). Transient histologic disease recurrence was confirmed in 4 (6.5%) of 62 patients with CR during the follow-up (median, 37.5 months). The OS and EFS probabilities after 5 years were 0.96 and 0.80, respectively. Second-line treatment was performed in 31 patients; gastrectomy in 4 patients, multiagent chemotherapy in 5 patients, OMC in 12 patients, and RT in 10 patients. There were no differences in the CR rate, OS, EFS, or toxicity between the OMC and RT groups. CONCLUSIONS: H. pylori eradication therapy was an effective first-line treatment for patients with gastric MALT lymphoma, which led to a favorable long-term outcome. OMC and RT had an equivalent efficacy as a second-line treatment in nonresponding patients to eradication therapy.

Adolescent↗

PubMed2005

Expression of BAFF-R (BR 3) in normal and neoplastic lymphoid tissues characterized with a newly developed monoclonal antibody.

BAFF-receptor (BAFF-R) is required for the successful maturation and survival of B-cells. We developed an anti-human BAFF-R monoclonal antibody (mAb), 8 A 7. The reactivity of 8 A 7 in normal and neoplastic tissue was examined by performing immunohistochemistry on paraffin-embedded sections. 8 A 7 reacted with lymphocytes in the mantle and marginal zones, but not with lymphocytes in the interfollicular area. Lymphocytes in the germinal centers were found to be negative or occasionally weakly positive for 8 A 7. BAFF-R expression was found only in B-cell lymphoma (44/80, positive cases/examined cases): B-lymphoblastic lymphoma 0/3, B-chronic lymphocytic leukemia/small lymphocytic lymphoma 4/4, mantle cell lymphoma 9/11, follicular lymphoma 10/14, diffuse large B-cell lymphoma (DLBCL) 11/25, marginal zone B-cell lymphoma 8/10, lymphoplasmacytic lymphoma 2/2, plasma cell myeloma 0/2, and Burkitt lymphoma 0/9, but not in T/NK cell lymphomas (0/19) or Hodgkin lymphoma (0/10). BAFF-R was expressed in most low-grade B-cell neoplasms and a small number of DLBCL, suggesting that BAFF-R may play an important role in the proliferation of neoplastic lymphoid cells. Thus, the mAb is very useful for further understanding of both healthy B-cell biology and its pathogenic neoplasms.

Antibodies, Monoclonal↗

PubMed2005

Comparison of genome profiles for identification of distinct subgroups of diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) comprises molecularly distinct subgroups such as activated B-cell-like (ABC) and germinal center B-cell-like (GCB) DLBCLs. We previously reported that CD5(+) and CD5(-)CD10(+) DLBCL constitute clinically relevant subgroups. To determine whether these 2 subgroups are related to ABC and GCB DLBCLs, we analyzed the genomic imbalance of 99 cases (36 CD5(+), 19 CD5(-)CD10(+), and 44 CD5(-)CD10(-)) using array-based comparative genomic hybridization (CGH). Forty-six of these cases (22 CD5(+), 7 CD5(-)CD10(+), and 17 CD5(-)CD10(-)) were subsequently subjected to gene-expression profiling, resulting in their division into 28 ABC (19 CD5(+) and 9 CD5(-)CD10(-)) and 18 GCB (3 CD5(+), 7 CD5(-)CD10(+), and 8 CD5(-)CD10(-)) types. A comparison of genome profiles of distinct subgroups of DLBCL demonstrated that (1) ABC DLBCL is characterized by gain of 3q, 18q, and 19q and loss of 6q and 9p21, and GCB DLBCL is characterized by gain of 1q, 2p, 7q, and 12q; (2) the genomic imbalances characteristic of the CD5(+) and CD5(-)CD10(+) groups were similar to those of the ABC and GCB types, respectively. These findings suggest that CD5(+) and CD5(-)CD10(+) subgroups are included, respectively, in the ABC and GCB types. Finally, when searching for genomic imbalances that affect patients' prognosis, we found that 9p21 loss (p16(INK4a) locus) marks the most aggressive type of DLBCL.

Adult↗

PubMed2005

The promoter of Milk vetch dwarf virus component 8 confers effective gene expression in both dicot and monocot plants.

The activity of a predicted promoter, PMC8, from Milk vetch dwarf virus was evaluated by comparing it with the cauliflower mosaic virus 35S RNA promoter (P35S) and PNCR, a promoter from Soybean chlorotic mottle virus. When the GUS fusion gene was introduced into tobacco, PMC8 showed a similar expression profile to P35S but with a more intense expression in proliferating tissues. The usefulness of PMC8 was confirmed by driving NPTII for selection of kanamycin-resistant tobacco plants with improved transformation efficiency. PMC8 was also effective in transgenic rice plants. Thus, PMC8 is useful as an alternative to P35S in both dicotyledonous and monocotyledonous plants, especially for gene expression in proliferating tissues.

Base Sequence↗

PubMed2005

Immunohistochemical evidence identifying the site of androgen production in the ovary of the protogynous grouper Epinephelus merra.

Androgen plays an important role in the developing ovaries of female fish. However, little is known regarding either the sites of production of androgen or its functional roles. In the present study, we investigated immunohistochemically the localization of cholesterol-side-chain-cleavage (P450scc) and cytochrome P45011beta-hydroxylase (P45011beta) with antibodies P450scc and P45011beta in the ovary of the female honeycomb grouper Epinephelus merra during its reproductive cycle. Clusters of strongly immunopositive cells, with 100-1000 cells in each cluster, against both P450scc and P45011beta, were observed throughout the annual reproductive cycle in tissue near blood vessels in the tunica ovary surrounding the outer periphery of the ovary. The ultrastructural characteristics of these cells showed that they were steroid-producing cells. In contrast, immunopositive cells against P450scc but not against P45011beta were localized in the theca layer surrounding the outer periphery of oocytes. These results suggest that two distinct steroid biosynthesis sites exist in the ovary and that cells at the two sites differ functionally. The only cells that biosynthesize 11-ketotestosterone are found in clusters in the vicinity of blood vessels; they possibly play a physiological role in oocyte growth and gonadal restructuring during the sex change of individuals of this species.

Androgens↗

PubMed2005

Genome-wide array-based CGH for mantle cell lymphoma: identification of homozygous deletions of the proapoptotic gene BIM.

Mantle cell lymphoma (MCL) is characterized by 11q13 chromosomal translocation and CCND1 overexpression, but additional genomic changes are also important for lymphomagenesis. To identify the genomic aberrations of MCL at higher resolutions, we analysed 29 patient samples and seven cell lines using array-based comparative genomic hybridization (array CGH) consisting of 2348 artificial chromosome clones, which cover the whole genome at a 1.3 mega base resolution. The incidence of identified genomic aberrations was generally higher than that determined with chromosomal CGH. The most frequent imbalances detected by array CGH were gains of chromosomes 3q26 (48%), 7p21 (34%), 6p25 (24%), 8q24 (24%), 10p12 (21%) and 17q23 (17%), and losses of chromosomes 2p11 (83%), 11q22 (59%), 13q21 (55%), 1p21-p22 (52%), 13q34 (52%), 9q22 (45%), 17p13 (45%), 9p21 (41%), 9p24 (41%), 6q23-q24 (38%), 1p36 (31%), 8p23 (34%), 10p14 (31%), 19p13 (28%), 5q21 (21%), 22q12 (21%), 1q42 (17%) and 2q13 (17%). Our analyses also detected several novel recurrent regions of loss located at 1p36, 1q42.2-q43, 2p11.2, 2q13, 17p13.3 and 19p13.2-p13.3, as well as recurrent regions of homozygous loss such as 2p11 (Ig(kappa)), 2q13 and 9p21.3-p24.1 (INK4a/ARF). Of the latter, we investigated the 2q13 loss, which led to identification of homozygous deletions of the proapoptotic gene BIM. The high-resolution array CGH technology allowed for the precise identification of genomic aberrations and identification of BIM as a novel candidate tumor suppressor gene in MCL.

Aged↗

PubMed2005

Human immunodeficiency virus-reverse transcriptase inhibition and hepatitis C virus RNA-dependent RNA polymerase inhibition activities of fullerene derivatives.

We examined the human immunodeficiency virus-reverse transcriptase and hepatitis C virus RNA-dependent RNA polymerase inhibition activities of cationic, anionic, and amino acid-type fullerene derivatives. Among the fullerene derivatives, the amino acid-type fullerene derivative was the most efficient in human immunodeficiency virus-reverse transcriptase inhibition.

Antiviral Agents↗

PubMed2005

Trisomy 3 may predict a poor response of gastric MALT lymphoma to Helicobacter pylori eradication therapy.

AIM: To investigate the relation of the response to Helicobacter pylori eradication therapy to the depth of tumor invasion and chromosome abnormalities in patients with mucosa-associated lymphoid tissue (MALT) lymphoma and to determine the clinical value of aneuploidy. METHODS: We studied 13 patients with localized gastric MALT lymphoma of stage E1. Before eradication therapy, the depth of tumor invasion was assessed by endoscopic ultrasonography in 8 patients and by endoscopic examination and gastrointestinal series in the remaining patients. To detect chromosomal abnormalities, paraffin-embedded tissue sections of diagnostic biopsy specimens underwent tissue-fluorescence in situ hybridization (FISH), using chromosome-specific alpha-satellite DNA probes for chromosomes 3,7,12, and 18 and YAC clones for t(11;18)(q21;q21). RESULTS: Seven of the 13 patients had complete regression (CR) in response to H pylori eradication therapy. No patient with CR had submucosal tumor invasion. Trisomy 18 was seen in 1 patient with CR, and both trisomies 12 and 18 were present in another patient with CR. All patients with no response or progressive disease had deep submucosal tumor invasion and showed t(11;18)(q21;q21) or trisomy 3. Trisomy 7 was not detected in this series of patients. CONCLUSION: The depth of tumor invasion is an accurate predictor of the response of stage E1 MALT lymphoma to H pylori eradication therapy and is closely associated with the presence of chromosomal abnormalities. Trisomy 3 may predict the aggressive development of MALT lymphoma.

Aged↗

PubMed2005

Cytotoxic T-cell non-Hodgkin's lymphoma of the thyroid gland.

An 86-year-old female was diagnosed with peripheral T-cell lymphoma, unspecified, which affected only her thyroid gland. Lymphoma cells were TIA-1(+), suggesting cytotoxic T-cell origin. She had not suffered from autoimmune thyroiditis and showed normal thyroid function. Without any specific therapies, the lymphomatous lesion showed the partial spontaneous regression before diagnostic hemithyroidectomy, and she had been well for 2 years without relapse. This is the first case of primary thyroid lymphoma of cytotoxic T-cell origin that showed spontaneous regression.

Aged↗

PubMed2005

Cytogenetic features of de novo CD5-positive diffuse large B-cell lymphoma: chromosome aberrations affecting 8p21 and 11q13 constitute major subgroups with different overall survival.

De novo CD5-positive diffuse large B-cell lymphoma (CD5(+)DLBCL) is regarded as a different clinicopathological entity from CD5-negative DLBCL (CD5(-)DLBCL) and mantle cell lymphoma (MCL). Because only a few published cytogenetic studies of de novo CD5(+)DLBCL are available, we investigated chromosomal changes in 23 Japanese patients who had de novo CD5(+)DLBCL. A characteristic of cytogenetic abnormalities in de novo CD5(+)DLBCL was a high incidence of chromosomal aberrations affecting 8p21 and 11q13. Major chromosomal breakpoints were concentrated at 8p21, 11q13, and 3q27. Patients with 8p21 aberrations showed aggressive clinical features, including advanced stage of disease, elevated serum LDH level, poor performance status, and an inferior survival curve compared with patients who had 11q13 changes (P = .043). Chromosomal abnormalities of both 8p21 and 11q13 were not observed in the same patient, and each abnormality showed different chromosomal gains and losses. These results indicate that de novo CD5(+)DLBCL may occur in previously unidentified subgroups that differ in their chromosomal abnormalities. The conflicting results of previous studies on prognosis may thus be explained in part by the differences in chromosomal changes.

Adult↗

PubMed2005

Genome-wide array-based comparative genomic hybridization of natural killer cell lymphoma/leukemia: different genomic alteration patterns of aggressive NK-cell leukemia and extranodal Nk/T-cell lymphoma, nasal type.

Natural killer (NK) cell lymphomas/leukemias are highly aggressive lymphoid malignancies, but little is known about their genomic alterations, and thus there is an urgent need for identification and analysis of NK cell lymphomas/leukemias. Recently, we developed our own array-based comparative genomic hybridization (array CGH) with an average resolution of 1.3 Mb. We performed an array CGH analysis for 27 NK-cell lymphoma/leukemia cases that were classified into two disease groups based on the World Health Organization Classification (10 aggressive NK-cell leukemia cases and 17 extranodal NK/T-cell [NK/T] lymphomas, nasal type). We identified the differences in the genomic alteration patterns of the two groups. The recurrent regions characteristic of the aggressive NK-cell leukemia group compared with those of the extranodal NK/T lymphoma, nasal-type group, were gain of 1q and loss of 7p15.1-p22.3 and 17p13.1. In particular, gain of 1q23.1-24.2 (P = 0.041) and 1q31.3-q44 (P = 0.003-0.047), and loss of 7p15.1-p22.3 (P = 0.012-0.041) and 17p13.1 (P = 0.012) occurred significantly more frequently in the former than in the latter group. Recurrent regions characteristic of the extranodal NK/T lymphoma, nasal-type group, compared with those of the other group were gain of 2q, and loss of 6q16.1-q27, 11q22.3-q23.3, 5p14.1-p14.3, 5q34-q35.3, 1p36.23-p36.33, 2p16.1-p16.3, 4q12, and 4q31.3-q32.1. Our results can be expected to provide further insights into the genetic basis of lymphomagenesis and the clinicopathologic features of NK-cell lymphomas/leukemias.

Adolescent↗

PubMed2005

Microsatellite instability is linked to loss of hMLH1 expression in advanced gastric cancers: lack of a relationship with the histological type and phenotype.

BACKGROUND: It has been suggested that the prevalence of microsatellite instability (MSI) is high in intramucosal differentiated gastric cancers with gastric foveolar phenotypic expression, and that these tumors are prone to lose their glandular structures and progress to undifferentiated-type lesions. To test this hypothesis, we examined the relationships among human MutL homologue 1 (hMLH1) expression (which is linked to MSI), the phenotype, and the histological type in patients with advanced and intramucosal gastric cancer. METHODS: We analyzed hMLH1 expression by immunohistochemistry in 70 advanced and 30 intramucosal gastric cancers with histological evaluation and assessment of the phenotype, and Cdx2 expression determined by immunohistochemistry. The MSI status was also examined in 20 cases. RESULTS: Thirteen (18.6%) advanced and 5 (16.7%) intramucosal gastric cancers were judged to be hMLH1-negative. In the advanced cases, no association was observed between the histological type and the phenotype and loss of hMLH1. In the intramucosal cases, MUC5AC expression was observed in all 5 hMLH1-negative differentiated-type cancers. However, no hMLH1-negative lesions were detected in the intramucosal undifferentiated cancers (0/14; P < 0.05 vs differentiated types). In the advanced cases, MSI-positivity (MSI +) and loss of hMLH1 expression did correlate (P < 0.0001), while no association was observed between MSI +, histological type, and phenotype. CONCLUSION: Our data support the hypothesis that, phenotypically, some MSI-positive differentiated gastric cancers of gastric foveolar phenotypic expression may easily change, from gastric to intestinal phenotypic expression, also changing, histologically, from differentiated to undifferentiated type with progression.

Adaptor Proteins, Signal Transducing↗