Motohiro Kojima

Autophagy is activated in pancreatic cancer cells and correlates with poor patient outcome.

Because autonomous proliferating cancer cells are often exposed to hypoxic conditions, there must be an alternative metabolic pathway, such as autophagy, that allows them to obtain energy when both oxygen and glucose are depleted. We previously reported finding that autophagy actually contributes to cancer cell survival in colorectal cancers both in vitro and in vivo. Pancreatic cancer remains a devastating and poorly understood malignancy, and hypoxia in pancreatic cancers is known to increase their malignant potential. In the present study archival pancreatic cancer tissue was retrieved from 71 cases treated by curative pancreaticoduodenectomy. Autophagy was evaluated by immunohistochemical staining with anti‐LC3 antibody, as LC3 is a key component of autophagy and has been used as a marker of autophagy. The results showed that strong LC3 expression in the peripheral area of pancreatic cancer tissue was correlated with a poor outcome (P = 0.0170) and short disease‐free period (P = 0.0118). Two of the most significant correlations among the clinicopathological factors tested were found between the peripheral intensity level of LC3 expression and tumor size (P = 0.0098) or tumor necrosis (P = 0.0127). Activated autophagy is associated with pancreatic cancer cells, and autophagy is thought to be a response to factors in the cancer microenvironment, such as hypoxia and poor nutrient supply. This is the first study to report the clinicopathological significance of autophagy in pancreatic cancer. (Cancer Sci 2008; 99: 1813–1819)

Glypican-3 expression is correlated with poor prognosis in hepatocellular carcinoma

The relationship between overexpression of glypican (GPC)‐3 that is specific for hepatocellular carcinoma (HCC) and the prognosis has not yet been clarified. We attempted to determine the expression profile of GPC3 in association with the clinicopathological factors by immunohistochemical analysis in HCC patients and investigated the potential prognostic value of GPC3 by comparing the survival rate between the GPC3‐positive and GPC3‐negative HCC patients. Primary HCC tissue samples (n = 107) obtained from patients who had undergone hepatectomy between 2000 and 2001 were analyzed. GPC3 expression was less frequently observed in well‐differentiated HCC than in moderately and poorly differentiated HCC, the difference in the frequency being statistically significant. GPC3‐positive HCC patients had a significantly lower 5‐year survival rate than the GPC3‐negative HCC patients (54.5 vs 87.7%, P = 0.031). Among 80 of the 107 (74.6%) patients with initial treatment who underwent hepatectomy, none of GPC3‐negative HCC patients (n = 16, 20.0%) died during the follow‐up period. No deaths were noted in the GPC3‐negative HCC patients among the 71 (88.7%) patients with moderately and poorly differentiated HCC. Multivariate analysis identified GPC3 expression (P = 0.034) as an independent prognostic factor for the overall survival. We showed that GPC3 expression is correlated with a poor prognosis in HCC patients. (Cancer Sci 2009)

Autoimmune pancreatitis: frequency, IgG4 expression, and clonality of T and B cells.

Autoimmune pancreatitis (AIP) is a newly recognized disease. The presence of IgG4 positive plasma cells is thought to be of diagnostic help. In a surgical series of chronic pancreatitis cases, we determined the relative frequency of AIP before and after 1990, analyzed the diagnostic significance of IgG4 expression and examined the presence of oligoclonal T or B-cell populations. The histopathology of 202 surgical specimens of chronic pancreatitis removed between 1975 and 2004 was reviewed and 2 groups were distinguished, 1 of AIP cases and the other of nonautoimmune chronic pancreatitis (non-AIP CP). The intensity of infiltration of pancreatic tissue by IgG4 positive plasma cells and other immune cells was studied immunohistochemically. Finally, T and B-cell clonality was tested by polymerase chain reaction-based analysis. Except for 1 case in 1978, all cases of AIP were observed after 1990. IgG4 positive plasma cells were detected in 72.5% of AIP cases and in 63.1% of non-AIP CP cases. More than 20 cells per high power field were only seen in AIP (sensitivity 43%, specificity 100%). This finding was associated with higher age and grade. Polyclonal T and B-cell populations were found in both AIP and non-AIP CP except for 1 AIP case showing an oligoclonal IgGH-FR3 gene rearrangement. AIP seems to have increased considerably in frequency in the last 2 decades. High density infiltrates of IgG4 positive plasma cells are diagnostic for AIP, but are seen in less than half of the cases. T or B-cell oligoclonality could not be established as a feature of AIP.

Immunohistochemical detection of CD133 expression in colorectal cancer: A clinicopathological study

CD133 has been reported to be a cancer‐initiating cell marker in colorectal carcinoma. The objective of this study was to evaluate the frequency of CD133 expression in colorectal cancer, the distribution of CD133‐positive cancer cells, and their relationship to clinicopathological features, including survival. An immunohistochemical examination of CD133 expression and a clinicopathological analysis were performed in the 189 consecutive colorectal cancer patients. CD133 expression was seen at the luminal surface of cancer glands mainly with cribriform features. Expression was detected in only 29 of the 189 tumors (15.3%). Of these, 21 tumors (11.1%) showed CD133 overexpression. All 21 tumors with CD133 overexpression were diagnosed as well‐ or moderately‐differentiated adenocarcinoma. There was no difference in the distribution of CD133 expressing cells between the invasive area and surface area. Although there was no difference in recurrence‐free survival between patients with CD133 overexpression and without, the patients with CD133 overexpression had significantly poorer overall survival (P = 0.03). CD133 overexpression is a risk factor for poorer overall survival in patients with well‐ and moderately‐differentiated adenocarcinoma. Expression of this cancer‐initiating cell marker may vary with the histological type of the cancer, and further investigation of the relationship between its expression and clinicopathological features may be necessary. (Cancer Sci 2008; 99: 1578–1583)

Podoplanin, a novel marker of tumor-initiating cells in human squamous cell carcinoma A431

Squamous cell carcinoma (SCC) is a malignant tumor that shows morphologic and phenotypic similarities to normally differentiated squamous epithelium. Thus, it may be an ideal model for seeking a marker of tumor-initiating cells (TICs) based on their morphology. Using the human SCC cell line A431, we found that, as a paradigm of cancer stem cells: (1) podoplanin(+) cells generate both podoplanin(+) and podoplanin(-) cells; (2) podoplanin(-) cells rarely generate podoplanin(+) cells; (3) podoplanin(+) cells have higher colony formation efficiency and tumorigenicity than podoplanin(-) cells; (4) localization and morphology of podoplanin(+) cells in a xenografted tumor derived from podoplanin(+) cells are similar with those in human oral SCC tissue or normal epithelium. Furthermore, podoplanin(+) A431 cells share sonic hedgehog and CD44 expression with stem cells in normal squamous epithelium. Hence, we concluded that podoplanin is a novel marker to enrich TICs with stem-cell-like properties from SCC cell line A431.

Autoimmune pancreatitis (AIP) type 1 and type 2: an international consensus study on histopathologic diagnostic criteria.

Objectives: To develop and validate histologic diagnostic criteria for autoimmune pancreatitis (AIP) and its types. Methods: Thirteen pathologists participated in this 2-phase study to develop diagnostic criteria for AIP types 1 and 2 (phase 1) and validate them (phase 2). A virtual library of 40 resected pancreata with AIP and other forms of chronic pancreatitis (CP) was constructed. Readers reviewed the slides online and filled out a questionnaire for histopathologic findings and diagnosis. Results: Diagnostic criteria for AIP and its types were proposed according to the results from the top 5 reviewers in phase 1. The interobserver agreement was significantly improved in phase 2 by applying the proposed diagnostic criteria. Features distinguishing AIP from alcoholic and obstructive forms of CP were periductal lymphoplasmacytic infiltrate, inflamed cellular stroma with storiform fibrosis, obliterative phlebitis, and granulocytic epithelial lesions. Although there was overlap, 2 types of AIP were recognized. Type 1 had dense lymphoplasmacytic infiltrate with storiform fibrosis and obliterative phlebitis, whereas type 2 was distinguished from type 1 by the presence of granulocytic epithelial lesions. Conclusions: Autoimmune pancreatitis can be distinguished from other forms of CP with substantial interobserver agreement. The 2 types of AIP can be distinguished by the proposed consensus histopathologic diagnostic criteria.

Autoimmune pancreatitis : histo- and immunopathological features

In recent years autoimmune pancreatitis (AIP) has been established as a special type of chronic pancreatitis. It is characterized by its histopathological and immunological features. The morphological hallmarks are periductal infiltration by lymphocytes and plasma cells, granulocytic epithelial lesions with focal destruction of the duct epithelium, venulitis, and diffuse sclerosis in advanced stages. AIP has therefore also been called lymphoplasmacytic sclerosing pancreatitis, duct-destructive chronic pancreatitis, or sclerosing pancreatitis. AIP most commonly involves the head of the pancreas and the distal bile duct. Occasionally it is mass-forming, and has been described as an inflammatory myofibroblastic tumor. The presence of more than 20 IgG4-positive plasma cells per high-power field is of high specificity for the tissue diagnosis of AIP.

MicroRNA Markers for the Diagnosis of Pancreatic and Biliary-Tract Cancers

It is difficult to detect pancreatic cancer or biliary-tract cancer at an early stage using current diagnostic technology. Utilizing microRNA (miRNA) markers that are stably present in peripheral blood, we aimed to identify pancreatic and biliary-tract cancers in patients. With “3D-Gene”, a highly sensitive microarray, we examined comprehensive miRNA expression profiles in 571 serum samples obtained from healthy patients, patients with pancreatic, biliary-tract, or other digestive cancers, and patients with non-malignant abnormalities in the pancreas or biliary tract. The samples were randomly divided into training and test cohorts, and candidate miRNA markers were independently evaluated. We found 81 miRNAs for pancreatic cancer and 66 miRNAs for biliary-tract cancer that showed statistically different expression compared with healthy controls. Among those markers, 55 miRNAs were common in both the pancreatic and biliary-tract cancer samples. The previously reported miR-125a-3p was one of the common markers; however, it was also expressed in other types of digestive-tract cancers, suggesting that it is not specific to cancer types. In order to discriminate the pancreato-biliary cancers from all other clinical conditions including the healthy controls, non-malignant abnormalities, and other types of cancers, we developed a diagnostic index using expression profiles of the 10 most significant miRNAs. A combination of eight miRNAs (miR-6075, miR-4294, miR-6880-5p, miR-6799-5p, miR-125a-3p, miR-4530, miR-6836-3p, and miR-4476) achieved a sensitivity, specificity, accuracy and AUC of 80.3%, 97.6%, 91.6% and 0.953, respectively. In contrast, CA19-9 and CEA gave sensitivities of 65.6% and 40.0%, specificities of 92.9% and 88.6%, and accuracies of 82.1% and 71.8%, respectively, in the same test cohort. This diagnostic index identified 18/21 operable pancreatic cancers and 38/48 operable biliary-tract cancers in the entire cohort. Our results suggest that the assessment of these miRNA markers is clinically valuable to identify patients with pancreato-biliary cancers who could benefit from surgical intervention.

Histopathologic Features of the Tumor Budding in Adenocarcinoma of the Lung: Tumor Budding As an Index to Predict the Potential Aggressiveness

Introduction: The term tumor budding has been applied to single cells or small clusters of up to four cells within the stromal tissue at the invasive margin of colorectal cancers. This morphologic feature is increasingly being recognized as an adverse prognostic factor. The purpose of this study was to evaluate the clinicopathologic significance of tumor budding in adenocarcinomas of the lung. Methods: We investigated the relationship between tumor budding and clinicopathologic parameters of adenocarcinomas of the lung and the prognostic significance of tumor budding by reviewing the cases of 201 consecutive patients who had undergone complete resection of adenocarcinoma of the lung measuring 30 mm or less in diameter. We examined immunohistochemical profile of budding cells (BCs) by immunohistochemical staining with 14 antibodies. Results: Tumor budding was observed in 78 (43.1%) of the 181 cases with invasive adenocarcinoma. The presence of tumor budding was significantly associated with lymph node metastasis (p = 0.005), pathologic stage (p < 0.001), vascular invasion (p = 0.003), lymphatic invasion (p = 0.009), and pleural invasion (p = 0.029). Examination of the relation between the presence of tumor budding and the predominant histologic subtype revealed that the predominant papillary subtype was significantly associated with the presence of tumor budding (p = 0.0023), whereas the predominant bronchioloalveolar carcinoma subtype was significantly associated with the absence of tumor budding (p < 0.001). The overall 5-year survival rates of the group with budding and the group without budding was 67.5% and 88.3%, respectively, and difference was significant (p = 0.0057). Compared with cancer cells forming nests, BCs displayed reduced expression of cellular adhesion molecule, E-cadherin, and β-catenin (p < 0.05 and p < 0.05, respectively) and increased expression of laminin5-γ2 (p < 0.05). However, BCs displayed reduced expression of differentiation marker, surfactant protein A (p < 0.05). Multivariate analysis revealed that tumor budding was significant independent prognostic factor of the small-sized adenocarcinoma of the lung. Conclusions: Our data showed that tumor budding in adenocarcinoma of the lung is a distinct morphologic feature that has biologic and prognostic significance.

Peritoneal elastic laminal invasion of colorectal cancer: the diagnostic utility and clinicopathologic relationship.

To determine whether the peritoneal elastic lamina can be a useful pathologic hallmark to classify the level of tumor spreading in colorectal cancer, we performed elastica staining in 564 pT3 and pT4a colorectal cancer cases. Associations between peritoneal elastic laminal invasion of the tumor and clinicopathologic features were evaluated. Next, morphology of tumor was compared between cases with and those without peritoneal elastic laminal invasion to estimate the morphologic alteration that occurs when tumor invades beyond the peritoneal elastic lamina. Morphometric analysis of tumor area beyond the peritoneal elastic lamina was performed and compared with other tumor area to elucidate morphologic characteristics of the tumor area beyond the peritoneal elastic lamina. Clinicopathologic analysis revealed that peritoneal elastic laminal invasion was associated with higher tumor stage, palliative resection, deeper tumor invasion, deeper ulceration, over 5 mm of muscular layer elevation and peritoneal surface retraction with fibro-inflammation, higher budding grade, and high grade of lymphovascular invasion (P<0.01). Peritoneal elastic laminal invasion was associated with recurrence and prognosis in colon cancer and was an independent risk factor for the recurrence of stage II colon cancer. Furthermore, morphometric analysis revealed that tumor area in subserosal invasive front beyond peritoneal elastic lamina exhibited significantly more prominent fibrosis and tumor budding than other tumor area (P<0.01). Peritoneal elastic lamina was useful hallmark to determine the level of tumor invasion, and was powerful indicator to predict prognosis in colon cancer. Tumor area beyond the elastic lamina is characterized by extensive tumor budding and fibrosis.