Kazuki Kanayama

Elimination of p19ARF-expressing cells enhances pulmonary function in mice

Senescent cells accumulate in many tissues as animals age and are considered to underlie several aging-associated pathologies. The tumor suppressors p19ARF and p16INK4a, both of which are encoded in the CDKN2A locus, play critical roles in inducing and maintaining permanent cell cycle arrest during cellular senescence. Although the elimination of p16INK4a-expressing cells extends the life span of the mouse, it is unclear whether tissue function is restored by the elimination of senescent cells in aged animals and whether and how p19ARF contributes to tissue aging. The aging-associated decline in lung function is characterized by an increase in compliance as well as pathogenic susceptibility to pulmonary diseases. We herein demonstrated that pulmonary function in 12-month-old mice was reversibly restored by the elimination of p19ARF-expressing cells. The ablation of p19ARF-expressing cells using a toxin receptor-mediated cell knockout system ameliorated aging-associated lung hypofunction. Furthermore, the aging-associated gene expression profile was reversed after the elimination of p19ARF. Our results indicate that the aging-associated decline in lung function was, at least partly, attributed to p19ARF and was recovered by eliminating p19ARF-expressing cells.

Tenascin-C May Accelerate Cardiac Fibrosis by Activating Macrophages via the Integrin αVβ3/Nuclear Factor–κB/Interleukin-6 Axis

Tenascin-C (TN-C) is an extracellular matrix protein not detected in normal adult heart, but expressed in several heart diseases closely associated with inflammation. Accumulating data suggest that TN-C may play a significant role in progression of ventricular remodeling. In this study, we aimed to elucidate the role of TN-C in hypertensive cardiac fibrosis and underlying molecular mechanisms. Angiotensin II was administered to wild-type and TN-C knockout mice for 4 weeks. In wild-type mice, the treatment induced increase of collagen fibers and accumulation of macrophages in perivascular areas associated with deposition of TN-C and upregulated the expression levels of interleukin-6 and monocyte chemoattractant protein-1 as compared with wild-type/control mice. These changes were significantly reduced in TN-C knockout/angiotensin II mice. In vitro, TN-C accelerated macrophage migration and induced accumulation of integrin &agr;V&bgr;3 in focal adhesions, with phosphorylation of focal adhesion kinase (FAK) and Src. TN-C treatment also induced nuclear translocation of phospho-NF-&kgr;B and upregulated interleukin-6 expression of macrophages in an NF-&kgr;B–dependent manner; this being suppressed by inhibitors for integrin &agr;V&bgr;3 and Src. Furthermore, interleukin-6 upregulated expression of collagen I by cardiac fibroblasts. TN-C may enhance inflammatory responses by accelerating macrophage migration and synthesis of proinflammatory/profibrotic cytokines via integrin &agr;V&bgr;3/FAK-Src/NF-&kgr;B, resulting in increased fibrosis.

Significant intratumoral heterogeneity of human epidermal growth factor receptor 2 status in gastric cancer: A comparative study of immunohistochemistry, FISH, and dual-color in situ hybridization.

The assessment of human epidermal growth factor receptor 2 (HER2) status is crucial for selecting patients with gastric cancer who may benefit from HER2‐targeted therapy. Accurate assessment using biopsy specimens is important for patients with advanced‐stage cancer. Intratumoral heterogeneity of HER2, however, is a major challenge in HER2 testing. Here, we aimed to examine whether assessment of HER2 status could be accurately carried out with currently used methods, namely, immunohistochemistry (IHC), FISH, and dual‐color in situ hybridization (DISH). Human epidermal growth factor receptor 2 status was evaluated in 108 biopsy tissues from patients with gastric adenocarcinoma and 70 matched surgical specimens by IHC, FISH, and DISH; HER2 amplification was detected in 11 (10.2%) out of 108 biopsy specimens. The IHC and FISH results were well correlated, and FISH and DISH results were consistent for all cases. The overall concordance rate of HER2 status between biopsy tissues and surgical specimens was 91.4%. All six discordant cases were false negative on biopsy; of these cases, five showed HER2 heterogeneity on surgical resection. Assessment of the HER2 status of biopsy tissues could predict the status of the whole tumor; however, a proportion of these cases may be discordant because of intratumoral heterogeneity.

Human Equilibrative Nucleoside Transporter 1 Expression in Endoscopic Ultrasonography-Guided Fine-Needle Aspiration Biopsy Samples Is a Strong Predictor of Clinical Response and Survival in the Patients With Pancreatic Ductal Adenocarcinoma Undergoing Gemcitabine-Based Chemoradiotherapy.

ObjectivesThis study aimed to clarify whether pretreatment human equilibrative nucleoside transporter (hENT1) expressions in endoscopic ultrasonography-guided fine-needle aspiration biopsy (EUS-FNAB) specimens obtained from resectable, borderline resectable, and locally advanced unresectable pancreatic ductal adenocarcinoma (PDAC) are concordant with those in the resected specimen after gemcitabine-based chemoradiotherapy (Gem-CRT) and to validate the utility of hENT1 expression using EUS-FNAB samples as a prognostic marker. MethodsWe evaluated the relationship between hENT1 expressions assessed by immunohistochemical staining and clinical outcomes in 51 of 76 patients with PDAC who were diagnosed by EUS-FNAB and received preoperative Gem-CRT. ResultsThe concordance rate of hENT1 expressions was 89.2% (K = 0.681). Median survival time (month) in the 51 whole patients and 37 patients with resection was significantly longer in hENT1 positive than in hENT1 negative: 25.0 and 30.0 versus 9.0 and 9.0, respectively. A multivariate analysis confirmed that hENT1 expression was an independent prognostic factor in both whole patients and those with resection. Regardless of T3 and T4, hENT1-positive patients with resection had significantly better prognosis than hENT1-negative patients, whose prognosis was similar to those without resection. ConclusionsThe assessment of hENT1 expression using EUS-FNAB samples before Gem-CRT provides important information on patients with PDAC who can benefit from curative-intent resection.

A case of pancreatic ductal adenocarcinoma with marked infiltration with IgG4-positive cells

A 75-year-old man was diagnosed as having pancreatic ductal carcinoma containing remarkable lymphocytic and plasma cell infiltration, as revealed by the cytological examination of endoscopic ultrasound guided fine-needle aspiration (EUS-FNA) specimen. The EUS-FNA specimen showed small amounts of atypical epithelium with noticeable lymphocytes and plasma cells. A pancreatic resection was performed, and the histopathological features showed an invasive pancreatic ductal carcinoma with autoimmune pancreatitis (AIP) lymphoplasmacytic sclerosing pancreatitis (LPSP)-like lesions. Most of the plasma cells were immunoreactive to anti-IgG4 antibody. EUS-FNA may be necessary for the differential diagnosis of AIP and pancreatic cancer, and close attention should be given to the presence of marked lymphoplasmacytic cells in EUS-FNA specimens while making the diagnosis.

Splenectomy increases the number of circulating hematopoietic stem/progenitor cells in patients with hepatitis C virus-associated liver cirrhosis

The spleen is not believed to contribute to hematopoiesis in healthy adults. However, several reports have demonstrated that the spleen in adults contains a large number of hematopoietic stem/progenitor cells (HSC). Although splenectomy increases platelet and leukocyte counts, the effects of splenectomy on circulating HSC have not been elucidated. In this study, we evaluated the association between the number of circulating HSC and splenectomy in patients with hepatitis C virus (HCV)‐associated liver cirrhosis (LC).

ASF-4-1 fibroblast-rich culture increases chemoresistance and mTOR expression of pancreatic cancer BxPC-3 cells at the invasive front in vitro, and promotes tumor growth and invasion in vivo

Pancreatic cancer develops dense stromal tissue through the desmoplastic reaction. The aim of the present study was to assess the effects of a fibroblast-rich environment on the malignant potential of pancreatic cancer. Cells from the human pancreatic cancer cell line BxPC-3 were mixed at a ratio of 1:3 (fibroblast-rich) or 1:1 (fibroblast-poor) with cells from the human skin fibroblast line ASF-4-1. In the fibroblast-rich co-culture, tumor budding was observed and BxPC-3 cells were found to be more resistant to gemcitabine than those in the fibroblast-poor co-culture. Immunohistochemistry revealed that the expression of mammalian target of rapamycin was increased at the invasive front of fibroblast-rich co-cultures. In addition, in mouse xenografts of fibroblast-rich co-cultures, tumors were larger and had a higher Ki-67 index compared with that of the fibroblast-poor co-culture xenografts. These results indicate that fibroblast-rich co-cultures may promote the malignant potential of the pancreatic cancer cell line BxPC-3, both in vitro and in vivo.

Cytological findings of an ectopic pancreas of the stomach obtained at endoscopic ultrasound-guided fine needle aspiration, differential diagnosis from acinar cell carcinoma: a case report.

An ectopic pancreas occurs in various sites of the gastrointestinal tract, such as the gastroesophageal junction, gastric antrum and jejunum. Because an ectopic pancreas tends to present as a submucosal mass, its clinical differential diagnosis includes a gastrointestinal stromal tumour (GIST) and neuroendocrine tumour (NET). Also, pancreatic-type acinar cell carcinoma (ACC) has been reported to occur in the stomach. Therefore, this should also be considered in the differential diagnosis. A few reports about the cytological findings of an ectopic pancreas using endoscopic ultrasound-guided-fine needle aspiration (EUS-FNA) have been published. Herein, we present a case of an ectopic pancreas of the stomach that was obtained using EUS-FNA, and discuss the cytological differential diagnosis from ACC.

A Study of Cervical Smear Cytology in Large Cell Neuroendocrine Carcinoma

We examined the possibility of diagnosing Large Cell Neuroendocrine Carcinoma (LCNEC) by cervical smear cytology. The study findings suggest that if a large number of consistent cytology characteristic features specific to LCNEC are observed in the specimen, such as salt and pepper chromatin, molding arrangement of the nuclei, rosette formation and palisade-like arrangement at the periphery of cell clumps, cytological diagnosis is possible.

Association of HER2 gene amplification and tumor progression in early gastric cancer

Overexpression of human epidermal growth factor receptor 2 (HER2) protein in association with HER2 gene amplification is found in 7–34% of gastric cancers. In breast cancer, HER2 overexpression is a prognostic factor in advanced cases and is associated with tumor progression in ductal carcinoma in situ. However, the biological and clinical significance of HER2 status in early gastric cancer is unknown. Here, we aimed to examine the correlation between HER2 gene amplification and tumor progression in early gastric cancer. The HER2 status was evaluated in 149 lesions from 141 consecutive patients with early gastric cancer who underwent endoscopic resection by immunohistochemistry and dual color in situ hybridization. HER2 gene amplification was detected in 35 (23.5%) of 149 lesions, and of those, 26 cases (74.3%) showed intratumoral heterogeneity. HER2 gene amplification was found in noninvasive carcinoma, and there was a significant correlation between HER2 status and T factor (P = 0.0290). Our study demonstrated that HER2 gene amplification occurred during the early stages of gastric cancer and showed heterogeneity in several cases. HER2 gene amplification may be involved in tumor progression in early gastric cancer.