Ichiro Kishimoto

National Hospital Organization Sagamihara Hospital, Sagamihara, Kanagawa, Japan

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Publications (6)10.89 Total impact

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    ABSTRACT: Gastrointestinal stromal tumors feature a wide spectrum of biologic behavior, ranging from benign to extremely malignant. To determine the role of p16(INK4a) alteration in progression of gastrointestinal stromal tumors of the stomach, we have investigated protein expression and gene methylation in correlation with clinicopathologic factors and survival. In addition to immunohistochemical analysis of p16(INK4a) in a series of 95 cases, real-time quantitative methylation specific polymerase chain reaction for p16(INK4a) and immunostaining for cyclin D1, cyclin E, pRb, DP-1, E2F-1, and Ki-67 were also evaluated in randomly selected samples. The p16(INK4a) labeling indices ranged from 0% to 74% (median, 21%), demonstrating a significant inverse correlation with size (P = .046). On univariate (P = .003) and multivariate (P = .067) analyses, loss of p16(INK4a) expression increased the likelihood of a poor tumor-related survival. In addition, size (P = .036) and the mitotic index (P = .005) had independent prognostic influence. The p16(INK4a) methylation index, which ranged from 0% to 100% (median, 17%), was significantly higher in larger tumors (P < .001) and in high-risk category lesions (P = .001) and inversely correlated with protein expression. Hierarchical cluster analysis based on expression of p16(INK4a) network members identified 2 clusters in 27 randomly selected tumor samples, containing 11 and 16 tumors each. Former cluster samples demonstrated higher risk category (P = .022), higher p16(INK4a) methylation (P < .001), and more reduced pRb expression (P < .018). In addition, p16(INK4a) network members clustered into 2 groups: (1) showing down-regulated p16(INK4a) protein and up-regulating of both cyclin D1 and DP-1 and (2) down-regulated pRb and up-regulated E2F-1. We conclude that p16(INK4a) alteration has an important role in progression of gastrointestinal stromal tumors of the stomach. Furthermore, the study provides a possible link between regulation of p16(INK4a) network members and gastrointestinal stromal tumors.
    Human pathology 04/2011; 42(10):1505-13. · 3.03 Impact Factor
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    ABSTRACT: We herein report two cases showing long-term complete remission (CR) in response to S-1 monotherapy. Case 1 was a 65-year-old male diagnosed with an advanced poorly differentiated adenocarcinoma of the stomach with paraaortic lymph node metastases, which disappeared after S-1 monotherapy. Subsequently a total gastrectomy was performed, and histological CR was evident. His progress is presently uneventful without recurrence 50 months after surgery. Case 2 was a 59-year-old female who underwent a total gastrectomy with a jejunal pouch. The resected tumor was a medullary type poorly differentiated adenocarcinoma infiltrating the serosa and involving the regional lymph nodes. One year after surgery, endoscopy revealed a recurrent tumor in the jejunal pouch. After the administration of S-1, this recurrent tumor completely disappeared, and she has since maintained CR for 39 months. These cases suggest that a subgroup of patients with advanced gastric cancer may attain CR with S-1 monotherapy.
    Cases Journal 01/2009; 1(1):405.
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    ABSTRACT: The p16(INK4a) (p16), cyclin D1, cyclin-dependent kinase (CDK) 4 and retinoblastoma (Rb) genes are components of the Rb pathway that controls the G1-S checkpoint of the cell cycle. The aim of this study was to assess the relationship between their abnormalities and clinicopathological features in gastric carcinomas. Immunohistochemical analysis of the encoded proteins was performed on a series of 158 cases. Loss of p16/Rb protein (pRb) expression and overexpression of cyclin D1/CDK4 were observed in 49%/40% and 37%/37% of gastric carcinomas, respectively. At least 1 of these abnormalities was found in 86% of the cases and a positive correlation was noted between p16 and pRb (P = 0.009). Cyclin D1 (P = 0.042) and CDK4 (P = 0.008) overexpession was inversely associated with lymph node metastasis and depth of invasion, respectively. Loss of pRb expression was more frequently in diffuse type lesions than in the intestinal type (P = 0.022). The patients with p16+/pRb-/cyclin D1-/CDK4- or p16-/pRb+/cyclin D1-/CDK4- tumors demonstrated particularly poor survival. With multivariate survival analysis, only depth of invasion and TNM stage could be proven as independent predictors. The Rb pathway is disrupted in the vast majority of gastric carcinomas. This study also identified specific immunohistochemical marker profiles for prognosis.
    Journal of Surgical Oncology 08/2008; 98(1):60-6. · 2.64 Impact Factor
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    ABSTRACT: Tumour budding, defined as small clusters of undifferentiated cancer cells at invasive margins, has been shown to reflect biologic aggressiveness of colorectal cancers. We therefore examined the prognostic significance of tumour budding in patients with colorectal carcinoma, particularly focusing on comparisons with other clinicopathological findings. Tumour budding was investigated in surgically resected specimens from 159 patients with colorectal carcinoma. With haematoxylin and eosin stained slides containing the entire invasive margin, the degree of tumour budding was classified into three grades: mild, <1/3 of the entire invasive margin; moderate, 1/3-2/3; marked, >2/3. Mild tumour budding was found in 54 (34%) cases, moderate in 59 (37%) cases and marked in 46 (29%) cases. The degree of budding was linked with poor tumour differentiation, lymph node metastasis and advanced TNM stage (P < 0.001). In univariate analysis, patients with marked tumour budding [5-year cancer-related survival (CRS)/recurrence-free survival (RFS), 39%/53%] had significantly worse survival [CRS, hazard ratio (HR), 4.561; 95% confidence interval (CI), 2.265-9.184; P < 0.001; RFS, HR, 3.240; 95% CI, 1.430-7.342; P = 0.005] than those with mild (5-year CRS/RFS, 80%/82%) or moderate (63%/66%) budding. In the Cox regression model, marked tumour budding (HR, 3.137; 95% CI, 1.517-6.487; P = 0.002) and advanced tumour stage (stage III, HR, 3.226; 95% CI, 1.475-7.053; P = 0.003; stage IV, HR, 24.443; 95% CI, 10.843-55.100; P < 0.001) proved to be an independent predictor of short CRS. Tumour budding is a practical and significant histological index for identification of high malignant potential and poor outcome in patients with colorectal carcinoma.
    Colorectal Disease 01/2008; 10(1):41-7. · 2.08 Impact Factor
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    ABSTRACT: P21WAF1/CIP1 is a cyclin-dependent kinase inhibitor activated by p53 to produce cell cycle arrest. A consensus has not been reached concerning the prognostic value of p21WAF1/CIP1 expression in colorectal cancers. P21WAF1/CIP1 expression was determined immunohistochemically in a series of 211 cases of colorectal carcinomas, together with its relation to p53, bcl-2, cell turnover (as assessed by Ki67 expression and apoptotic counts) and the Kras gene status. The expression of p21WAF1/CIP1 was also compared with reference to clinicopathological parameters and patient survival. The median value for nuclear p21WAF1/CIP1 expression was 31% (interquartile range, 13-47%) and the fraction of cases considered to be high expressers (>20%) was 66%. Expression of p21WAF1/CIP1 was not associated with immunoreactivity for p53 or bcl-2, or cell turnover. P21WAF1/CIP1 high-expressing tumors were more often well differentiated (P<0.001), node-negative (P=0.037), Dukes' B (P=0.027) and Kras gene-mutated cases (P=0.04). On univariate analysis, low p21WAF1/CIP1 expressers (<or=20%) had lower cancer-related survival as compared with high expressers (5-year survival, 56 vs. 70%; P=0.042). Lymph node status, liver metastasis and tumor size were also significant predictors. Multivariate analysis revealed lymph node-positive (P<0.001), liver metastasis (P<0.001), and low p21WAF1/CIP1 expression (P=0.017) to be independent predictors of short survival. The regulation of p21WAF1/CIP1, independent of p53 or bcl-2 expression, appears to be associated with Kras mutations. The immunohistochemical detection of p21WAF1/CIP11 might thus be used to predict more precise outcome in colorectal cancer patients.
    European Journal of Gastroenterology & Hepatology 10/2007; 19(10):883-9. · 1.92 Impact Factor
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    ABSTRACT: In spite of the clinicopathological differences between Crohn's disease (CD) and ulcerative colitis (UC), they share the fundamental feature of destructive inflammatory processes involving the intestinal wall. The aim of the present study was to investigate the contribution of cell-mediated cytotoxicity to mucosal damage in CD and UC. Colonic mucosal biopsy specimens from patients with active CD (n=25) and UC (n=26) and normal controls (n=12) were immunohistochemically analyzed for the expression of CD3, CD4, CD8, and T cell-restricted intracellular antigen (TIA)-1, which promotes apoptosis by alternative splicing of pre-messenger RNA of the Fas receptor, and granzyme B (GrB), which leads to apoptosis through induction of perforin. Histological scores for cryptal apoptosis and ulceration were assessed in hematoxylin- and eosin-stained sections. In patients with CD and UC, CD3+(P<0.001), CD4+(P<0.001), CD8+(P<0.01), TIA-1+(CD, P<0.01; UC, P<0.001), and GrB+(CD, P<0.01; UC, P<0.001) intraepithelial lymphocytes (IELs) were significantly increased as compared with controls. Positive relationships were found between the histological scores for apoptosis or ulceration and the numbers of CD8+or TIA-1+IELs. In conclusion, cytotoxic T lymphocytes are present in increased numbers in the mucosa of patients with active CD and UC, and local activation of IELs may contribute to mucosal damage with these diseases.
    Pathology - Research and Practice 01/2007; 203(10):717-23. · 1.21 Impact Factor