Naoshi Kubo

Cronkhite-Canada syndrome containing colon cancer and serrated adenoma lesions.

We describe a case of Cronkhite-Canada syndrome associated with sigmoid colon cancer, and provide a literature review. A 77-year-old man was diagnosed with sigmoid colon cancer after presenting with hypoproteinemia, nail atrophy, loss of scalp hair, hyperpigmentation, and gastrointestinal polyposis. The findings were consistent with Cronkhite-Canada syndrome. The colon polyps were histologically serrated adenomas, whose crypts showed a saw-toothed growth pattern with dysplasia, or tubular adenoma. Cronkhite-Canada syndrome associated with colon cancer has been reported in 31 cases. The availability of histologic material permitted reexamination of 25 of these cases. Serrated adenoma of the polypoid lesions was retrospectively found in 10 (40%) of the 25 cases. By comparison, the incidence of serrated adenomas has been estimated to occur in about 1% of all general polyps. Taken together, it is suggested that Cronkhite-Canada syndrome associated with colorectal cancer frequently has polyps containing serrated adenoma lesions. In the case described here, microsatellite instability and overexpression of the p53 protein were found in the cancer lesion and serrated adenoma lesions, and none of the lesions showed a loss of heterozygosity of various genes or K-ras mutations. Thus, genetic alterations between the serrated adenoma and the colorectal cancer was correlated in this case. These findings suggested the possibility of a serrated adenoma-carcinoma sequence in this case of Cronkhite-Canada syndrome.

Ulcerative Colitis-Associated Colorectal Cancer is Frequently Associated with the Microsatellite Instability Pathway

PurposePatients with ulcerative colitis have a high risk for the development of colorectal cancer. To understand the molecular mechanisms of the carcinogenesis process of ulcerative colitis-associated colorectal cancer, the genetic alterations in inflamed or neoplastic colon epithelium in ulcerative colitis were analyzed.MethodsFifty-seven patients with ulcerative colitis were enrolled in this study. Specimens were obtained from the patients randomly at six colonic sites. Each patient was histologically classified according to the worst pathologic finding into cancer, dysplasia, indefinite, and normal cases. Microsatellite instability, mutations of target genes, hypermethylation of the hMLH1 promoter region, and mismatch repair protein expression were analyzed.ResultsHigh-microsatellite instability was found in 4 of 11 cancer cases (36 percent), 5 of 15 dysplasia cases (33 percent), 5 of 11 indefinite cases (45 percent), and none of 20 normal cases (0 percent). A significant correlation was found between the malignant potential and high-microsatellite instability. A frameshift mutation of transforming growth factor β receptor Type II (TGFβRII) was significantly correlated with worsening histologic grade. High-microsatellite instability was significantly associated with hMLH1 hypermethylation and loss of hMSH2 expression.ConclusionThe carcinogenesis process in ulcerative colitis-associated colorectal cancer was closely associated with the microsatellite instability pathway through TGFβRII mutation by a dysfunction of the mismatch repair system.

Usefulness of Non-Magnifying Narrow-Band Imaging in Screening of Early Esophageal Squamous Cell Carcinoma: A Prospective Comparative Study Using Propensity Score Matching

OBJECTIVES:The usefulness of non-magnifying endoscopy with narrow-band imaging (NBI; NM-NBI) in the screening of early esophageal squamous cell carcinoma (SCC) and high-grade intraepithelial neoplasia (HGIN) remains unclear. Here, we aimed to compare NM-NBI and chromoendoscopy with iodine staining (CE-Iodine) in terms of the diagnostic performance, and to evaluate the usefulness of NM-NBI in detecting early esophageal SCC.METHODS:We prospectively enrolled 202 consecutive patients (male/female=180/22; median age, 67 years) with high-risk factors for esophageal SCC. All patients received endoscopic examination with NM-NBI and CE-Iodine to screen for early esophageal SCC or HGIN. We conducted the examinations sequentially, and calculated the accuracy, sensitivity, and specificity through a per-lesion-based analysis. A propensity score matching analysis was performed to reduce the effects of selection bias, and we compared the respective outcomes according to NM-NBI and CE-Iodine after matching.RESULTS:The accuracy, sensitivity, and specificity of NM-NBI were 77.0, 88.3, and 75.2%, respectively, and those for unstained areas by CE-Iodine were 68.0, 94.2, and 64.0, respectively. The accuracy and specificity of NM-NBI were superior to those of CE-Iodine (P=0.03 and P=0.01, respectively). However, the sensitivity did not significantly differ between NM-NBI and CE-Iodine (P=0.67). The accuracy and specificity of NM-NBI before matching were superior to those of CE-Iodine after matching (P=0.04 and P=0.03).CONCLUSIONS:NM-NBI was useful and reliable for the diagnosis of esophageal SCC and can be a promising screening strategy for early esophageal SCC.

Expression of Forkhead box P3 in tumour cells causes immunoregulatory function of signet ring cell carcinoma of the stomach

Background:It was recently reported that the transcription factor Forkhead box P3 (FoxP3) is expressed not only in regulatory T cells (Tregs) but also in cancer cells. The aim of this study was to clarify the clinical significance of FoxP3 expression in gastric carcinoma.Methods:We performed immunohistochemical staining of FoxP3 to examine the association of FoxP3 expression with clinicopathological features of 194 patients with gastric cancer who underwent surgical resection from 2000 to 2010. We also investigated the immunosuppressive function of FoxP3 using gastric cancer cell lines.Results:Immunohistochemical staining indicated FoxP3-positive cells within tumour tissue including both Tregs and tumour cells. Forkhead box P3-positive tumour cells were observed in 79.3% of signet ring cell carcinoma patients, and the expression of FoxP3 showed a significant correlation with lymph node metastasis. We showed that transforming growth factor-β augmented FoxP3 mRNA expression in cell lines derived from signet ring cell carcinoma. Indoleamine-2,3-dioxygenase and galectin-1, key effectors of Treg-mediated immunosuppression, were downregulated by FoxP3 knockdown.Conclusion:Our findings suggested that FoxP3 expression by tumour cells might have important roles in immune escape of gastric carcinoma, and be associated with the malignant potential of scirrhous gastric carcinoma.

Phosphorylated Smad2 in Advanced Stage Gastric Carcinoma

BackgroundTransforming growth factor β (TGFβ) receptor signaling is closely associated with the invasion ability of gastric cancer cells. Although Smad signal is a critical integrator of TGFβ receptor signaling transduction systems, not much is known about the role of Smad2 expression in gastric carcinoma. The aim of the current study is to clarify the role of phosphorylated Smad2 (p-Smad2) in gastric adenocarcinomas at advanced stages.MethodsImmunohistochemical staining with anti-p-Smad2 was performed on paraffin-embedded specimens from 135 patients with advanced gastric adenocarcinomas. We also evaluated the relationship between the expression levels of p-Smad2 and clinicopathologic characteristics of patients with gastric adenocarcinomas.ResultsThe p-Smad2 expression level was high in 63 (47%) of 135 gastric carcinomas. The p-Smad2 expression level was significantly higher in diffuse type carcinoma (p = 0.007), tumours with peritoneal metastasis (p = 0.017), and tumours with lymph node metastasis (p = 0.047). The prognosis for p-Smad2-high patients was significantly (p = 0.035, log-rank) poorer than that of p-Smad2-low patients, while a multivariate analysis revealed that p-Smad2 expression was not an independence prognostic factor.ConclusionThe expression of p-Smad2 is associated with malignant phenotype and poor prognosis in patients with advanced gastric carcinoma.

Lysyl oxidase-like 2 (LOXL2) from stromal fibroblasts stimulates the progression of gastric cancer

The aim of this study was to clarify the role of fibroblast-derived Lysyl oxidase-like 2 (LOXL2) in the development of gastric cancer. The correlation between the clinicopathological features of 548 primary gastric carcinomas and LOXL2 expression in stromal cells was examined by immunohistochemistry. Two gastric cancer cell lines, OCUM-12 and NUGC-3, and cancer-associated fibroblasts (CAFs) were used in this in vitro study. The effect of fibroblast-derived LOXL2 on the motility of gastric cancer cells was analyzed by using a wound-healing assay, a double-chamber invasion assay, and western blot. LOXL2 expression in stromal cells was significantly associated with tumor invasion depth, lymph node metastasis, lymphatic invasion, venous invasion, and peritoneal dissemination. Multivariable logistic regression analysis revealed that LOXL2 expression in stromal cells could be an independent predictive parameter for the overall survival of patients. CAFs significantly stimulated the migration and invasion of OCUM-12 and NUGC-3 cells. This motility-stimulating ability of CAFs was inhibited by LOXL2 siRNA. Western blot analysis indicated that phosphorylation of focal adhesion kinase (FAK) in cancer cells was increased by the conditioned medium from CAFs, and was decreased by the conditioned medium from LOXL2 siRNA-treated CAFs. LOXL2 expression in stromal cells may be a useful prognostic factor for patients with gastric cancer. Fibroblast-derived LOXL2 may stimulate the motility of gastric cancer cells.

The outcome of surgical treatment for elderly patients with gastric carcinoma

The aim of this study was to clarify the operative mortality and long‐term survival of gastrectomy for elderly patients with gastric cancer.

Lysyl oxidase is associated with the epithelial-mesenchymal transition of gastric cancer cells in hypoxia.

PurposeIt has been reported that lysyl oxidase (LOX) is a hypoxia-responsive factor and is associated with the malignant progression of carcinoma. The aim of this study was to clarify the relationship between the epithelial–mesenchymal transition (EMT) and LOX in gastric cancer cells under hypoxia.MethodsTwo gastric cancer cell lines, OCUM-2MD3 and OCUM-12, were used in an in vitro study. The effect of LOX small interfering RNA (siRNA) on the EMT and motility of gastric cancer cells under hypoxic condition was analyzed by reverse transcription PCR, Western blot, a wound-healing assay, and an invasion assay. Correlations between LOX expression and the clinicopathological features of 544 patients with gastric carcinoma were examined immunohistochemically.ResultsHypoxic conditions increased the number of polygonal or spindle-shaped cells resulting from EMT in gastric cancer cells. The EMT of cancer cells induced by hypoxia was inhibited by treatment with LOX siRNA. The number of migrating and invading gastric cancer cells in hypoxia was significantly decreased by LOX knockdown. LOX siRNA significantly increased the E-cadherin level and decreased the vimentin level of gastric cancer cells. LOX expression was significantly associated with invasion depth, tumor differentiation, lymph node metastasis, lymphatic invasion, venous invasion, and peritoneal metastasis. Multivariable analysis revealed that LOX was an independent parameter for overall survival.ConclusionLOX affects the EMT of gastric cancer cells in hypoxic conditions. LOX expression is a useful prognostic factor for patients with gastric cancer.

Comparative Proteomics Analysis of Gastric Cancer Stem Cells

Cancer stem cells (CSCs) are responsible for cancer progression, metastasis, and recurrence. To date, the specific markers of CSCs remain undiscovered. The aim of this study was to identify novel biomarkers of gastric CSCs for clinical diagnosis using proteomics technology. CSC-like SP cells, OCUM-12/SP cells, OCUM-2MD3/SP cells, and their parent OCUM-12 cells and OCUM-2MD3 cells were used in this study. Protein lysates from each cell line were analyzed using QSTAR Elite Liquid Chromatography with Tandem Mass Spectrometry, coupled with isobaric tags for relative and absolute quantitation technology. Candidate proteins detected by proteomics technology were validated by immunohistochemical analysis of 300 gastric cancers. Based on the results of LC-MS/MS, eight proteins, including RBBP6, GLG1, VPS13A, DCTPP1, HSPA9, HSPA4, ALDOA, and KRT18, were up-regulated in both OCUM-12/SP cells and OCUM-2MD3/SP cells when compared to their corresponding parent cells. RT-PCR analysis indicated that the expression level of RBBP6, HSPA4, DCTPP1, HSPA9, VPS13A, ALDOA, GLG1, and CK18 was high in OCUM-12/SP and OCUM-2MD3/SP, in compared with the control of parent OCUM-12 and OCUM-2MD3. These proteins were significantly associated with advanced invasion depth, lymph node metastasis, distant metastasis, or advanced clinical stage. RBBP6, DCTPP1, HSPA4, and ALDOA expression in particular were significantly associated with a poor prognosis in the 300 gastric cancer patients. RBBP6 was determined to be an independent prognostic factor. The motility-stimulating ability of OCUM-12/SP cells and OCUM-2MD3/SP cells was inhibited by RBBP6 siRNA. These findings might suggest that the eight proteins, RBBP6, GLG1, VPS13A, DCTPP1, HSPA9, HSPA4, ALDOA, and KRT18, utilizing comparative proteomics analysis, were perceived to be potential CSC markers of gastric cancer. Of the eight candidate proteins, RBBP6 was suggested to be a promising prognostic biomarker and a therapeutic target for gastric cancer.

Role of tumor-infiltrating CD11b+ antigen-presenting cells in the progression of gastric cancer.

BACKGROUND Tumor-infiltrating antigen-presenting cells (APCs), involving tumor-associated macrophages and tumor-infiltrating dendritic cells, play an important role in tumor immunity and immune escape. The aim of this study was to determine whether tumor infiltrating CD11b(+) APCs may affect tumor progression and clinical outcome. METHODS The immunohistochemical analysis was used to evaluate the expression of CD11b, FOXP3, and CD8 in 214 gastric cancer tissues. Concentrations of immunosuppressive cytokines in medium conditioned by gastric cancer cells were measured by enzyme-linked immunosorbent assay. Effects of addition of tumor-conditioned media on CD11c(+) cells were examined by flow cytometry. RESULTS Almost all tumor-infiltrating CD11b(+) cell expressed CD11c and was considered to be APCs. High CD11b(+) cell infiltration was significantly correlated with huge tumor, positive venous invasion, lymph node metastasis, and tumor, node, metastasis stage. Patients with high CD11b(+) cell infiltration had a poorer surgical outcome than those with low CD11b infiltration. Multivariate analysis revealed that CD11b(+) cell infiltration was one of the independent prognostic factors. Tumor-conditioned medium obtained from several gastric cancer cell lines contained immunosuppressive cytokines, transforming growth factor-beta, interleukin-10, and vascular endothelial growth factor. The addition of tumor-conditioned medium decreased the expression of major histocompatibility complex-II and increased the expression of CD11b and programmed death ligand 2 on CD11c(+) APCs. Infiltration of CD11b(+) cells significantly correlate with the degree of FOXP3(+) cell infiltration but not with CD8(+) cell infiltration. CONCLUSIONS Tumor-infiltrating CD11b(+) APCs affected local tumor cell-immune cell interactions and correlated to the poor prognosis of the patients with gastric cancer.