miR-4653-3p overexpression is associated with a poor prognosis of pancreatic ductal adenocarcinoma via HIPK2 downregulation.

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignant tumor. Several upregulated and downregulated microRNAs (miRNAs) are associated with invasiveness, tumorigenesis, and prognosis of PDAC. Herein, using in situ hybridization, we evaluated miR-4653-3p expression and pancreatic intraepithelial neoplasia (PanIN) and the association between miR-4653-3p expression and clinicopathological factors in PDAC patients. The miR-4653-3p target was also identified. Ninety PDAC cases, including 30 each with normal pancreatic ducts, low-grade PanINs, and high-grade PanINs, were evaluated. miR-4653-3p expression increased in the order-normal pancreatic duct, low-grade PanIN, high-grade PanIN, and PDAC-with no expression detected in normal pancreatic duct. High expression significantly correlated with advanced pathological T stage, lymph node metastasis, advanced Union for International Cancer Control stage, perineural invasion, venous involvement, and shorter overall and disease-specific survival. Homeodomain Interacting Protein Kinase 2 (HIPK2) was identified as a miR-4653-3p target based on mRNA microarray analysis and database screening. In MIA PaCa-2 cells, miR-4653-3p significantly downregulated HIPK2 expression. HIPK2 expression, unlike that of miR-4653-3p, decreased in the order-normal pancreatic duct, low-grade PanIN, high-grade PanIN, and PDAC. Low HIPK2 expression was associated with shorter overall and disease-specific survival in PDAC patients. Thus, miR-4653-3p associates with tumorigenesis and worse prognosis, partly by reducing HIPK2 expression.

Low expression of DDX5 is associated with poor prognosis in patients with pancreatic ductal adenocarcinoma.

AIMS: Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal malignancies. Hence, there is a need for new markers and treatment strategies. P68/DEAD box protein 5 (DDX5) is an ATP-dependent RNA helicase of the DEAD box protein family. It is a prognostic marker for several cancers. In this study, we aimed to evaluate the expression and clinical relevance of DDX5 in PDAC. METHODS: DDX5 expression in tissue microarray blocks containing 230 PDAC samples was examined using immunohistochemical analysis. DDX5 expression was considered high when more than 50% of the cells were stained and low when less than 50% of the cells were stained. We investigated the association between DDX5 expression and clinicopathological parameters, including patient survival. RESULTS: The nuclei of normal pancreatic ducts, normal acinar cells and PDAC cells were stained positive for DDX5 although the intensity and distribution of DDX5 expression varied. Islet cells showed strong and diffuse staining of DDX5. DDX5 expression was low and high in 148 (64.3%) and 82 cases (35.7%), respectively. Low DDX5 expression was significantly associated with an advanced pT factor (pT2-pT3: tumour size,>20 mm), lymphatic involvement, advanced tumour-node-metastasis (TNM) stage (stages IIB, III, and IV), and venous involvement. In addition, the multivariate analysis revealed that DDX5 expression is an independent prognostic factor for PDAC. CONCLUSION: These results suggest that DDX5 plays an important role in tumour invasiveness and PDAC prognosis.

Hyalinized stroma is a characteristic feature of pancreatic intraductal oncocytic papillary neoplasm: An immunohistochemical study.

Hyalinized stroma (HS) is a dense, eosinophilic, and amorphous extracellular material in the stroma. HS is observed in several tumors; however, it has not been comprehensively studied in pancreatic intraductal papillary mucinous neoplasm (IPMN) or intraductal oncocytic papillary neoplasm (IOPN). Here, we aimed to evaluate the immunohistochemical and microscopic characteristics of HS in IPMN and IOPN. The prevalence of HS was determined in 168 cases of IPMN, including intestinal type (IPMN-I), gastric type (IPMN-G), and pancreatobiliary type (IPMN-PB), as well as in 11 cases of IOPN. Immunohistochemical staining for laminin and collagen (types I, II, III, IV, and V), as well as Congo red staining were performed in IPMN and IOPN cases containing HS. The prevalence of HS among the IPMN and IOPN specimens was 1.2% (2/168 cases) and 45.5% (5/11 cases), respectively. The prevalence rates of HS in each IPMN subtype were as follows: 2.2% (2/91 cases) in IPMN-G, and 0% in IPMN-PB and IPMN-I. All seven HS cases were positive for collagen I, III, IV, and V but were negative for Congo red staining. Most cases showed negative, focal, or weak expression of laminin and type II collagen. These findings indicate that HS is associated with IOPN and is primarily composed of collagen fibers.

Histological and immunohistochemical analyses of splenic epidermoid cysts.

Splenic epidermoid cyst (SEC) is a rare condition. We aimed to evaluate the immunohistochemical profiles of the epithelial lining of SECs. A total of 7 SEC cases were analyzed: 2 cases involved a monolayered epithelial lining and 5 cases involved a multilayered epithelial lining. Among the multilayered SECs, the superficial/luminal layer showed mucin 4 (MUC4), cytokeratin 5/6 (CK5/6), and CK7 expression in 5 cases (100%); MUC1, carcinoembryonic antigen (CEA), CA19-9, and thrombomodulin expression in 4 cases (80%); Wilms' tumor-1 (WT-1) and Hector Battifora mesothelial-1 (HBME-1) expression in 2 cases (40%), but it did not express p63 or D2-40. The basal layer expressed MUC1, CK5/6, p63, and thrombomodulin in 5 cases (100%); CK7 and WT-1 in 4 cases (80%); D2-40 in 3 cases (60%); CA19-9 and HBME-1 in 2 cases (40%) and MUC4 in 1 case (20%) but it did not express CEA. The analysis showed that all cases of multilayered SECs were negative for MUC2, MUC5AC, MUC6, CK20, calretinin, uroplakin-II, and uroplakin-III. Both cases of monolayered SECs expressed CK5/6, CK7, HBME-1, WT-1, and thrombomodulin but not MUC2, MUC4, MUC5AC, MUC6, p63, CEA, CK20, CA19-9, D2-40, uroplakin-II, or uroplakin-III. One case of monolayered SEC expressed MUC1 and calretinin. Our findings indicate that monolayered SECs have mesothelial-like characteristics, whereas multilayered SECs have glandular and squamous-like characteristics besides mesothelial-like characteristics. Furthermore, monolayered SECs may develop from mesothelial inclusion and monolayered SECs develop squamous and glandular metaplasia, which results in multilayered SECs.

Nectin-1 expression in cancer-associated fibroblasts is a predictor of poor prognosis for pancreatic ductal adenocarcinoma.

PURPOSE: Nectin-1 is a cell adhesion molecule that regulates the formation of adherens junctions and tight junctions. We measured the expression of nectin-1 in cancer-associated fibroblasts (CAFs) in patients with pancreatic ductal adenocarcinoma (PDAC). METHODS: Nectin-1 expression was measured via immunohistochemistry using tissue microarray blocks constructed from resected PDAC tissue from 258 patients. We screened for associations between nectin-1 expression and clinicopathological parameters. According to the percentage of CAFs stained, expression was classified as negative at ≤ 30% and positive at > 30%. RESULTS: Nectin-1 expression was confirmed in CAFs from 64 patients (24.8%), and was associated with lymph node metastasis (p = 0.016), advanced Union for International Cancer Control stage (p = 0.016), perineural invasion (p = 0.022), pancreatic head tumors (p = 0.023), and shorter overall survival (p = 0.003). Multivariate analysis revealed that nectin-1 expression in CAFs was an independent prognostic factor (p = 0.038). CONCLUSIONS: Diffuse nectin-1 expression in the CAFs of PDAC patients is associated with invasion, metastasis, and shorter survival.

Epidermoid cysts are a characteristic feature of intrapancreatic but not of extrapancreatic accessory spleens.

Accessory spleens (ASs), ectopic splenic tissue at intrapancreatic and extrapancreatic sites, rarely contain epidermoid cysts. Our aim was to analyze the incidence of epidermoid cysts in ASs and perform an immunohistochemical analysis of its epithelial lining. We included in the study 148 ASs from 135 patients, for which pathological data were available. Eleven were intrapancreatic ASs (IPASs) and 137 were extrapancreatic ASs (EPASs). Six of the eleven (55%) IPASs contained epidermoid cysts, but they were not detected in EPASs. Immunohistochemical analysis showed that both the superficial/luminal and basal layer of the epithelial lining of epidermoid cysts in IPASs are negative for MUC2, MUC5AC, MUC6, WT-1, calretinin, thrombomodulin, uroplakin-II, and uroplakin-III. The superficial/luminal layer was positive for MUC4, CK7, and CA19-9 in all cases (100%), for CEA and HBME-1 in three cases (50%), and for MUC1, CK5/6, and CK20 in two cases (33%). The superficial/luminal layer was negative for p63 and D2-40 in all cases. The basal layer was positive for MUC1, CK5/6, p63, and HBME-1 in all six cases (100%), for CK7 and D2-40 in two cases (33%), and for CEA in one case (17%). The basal layer was negative for MUC4, CK20, and CA19-9 in all cases. Epidermoid cysts are a characteristic feature of IPASs but not of EPASs. Immunohistochemical analysis showed that the epithelial lining of epidermoid cysts in IPASs has a mixed character of glandular, squamous, mesothelial, and urothelial epithelium.

A Serous Cystic Neoplasm of the Pancreas Coexisting with High-Grade Pancreatic Intraepithelial Neoplasia Mimicking an Intraepithelial Papillary Mucinous Neoplasm: A Case Report.

Serous cystic neoplasms of the pancreas are rare exocrine pancreatic neoplasms, most of which are benign and do not communicate with the pancreatic duct. Pancreatic intraepithelial neoplasm (PanIN) is considered a precursor of ductal adenocarcinoma that is microscopically recognized in pancreatic ducts. A 67-year-old Japanese woman presented with a 10-mm multilocular cystic lesion at the pancreatic body. Magnetic resonance pancreatography showed stenosis of the main pancreatic duct at the pancreatic body and dilatation of the distal side of the main pancreatic duct. Furthermore, communication between the cystic lesion and the main pancreatic duct was suspected based on magnetic resonance pancreatography findings. Distal pancreatectomy was performed under the preoperative diagnosis of intraductal papillary mucinous neoplasm. Histologically, the cystic lesion was lined with a non-atypical cuboidal or flat epithelium with clear cytoplasm and was thus diagnosed as a serous cystic neoplasm. High-grade PanIN lesions with stromal fibrosis were observed at the main and branch pancreatic ducts. Histological examination revealed no communication between the serous cystic neoplasm and the pancreatic ducts. Immunohistochemically, the epithelium of the serous cystic neoplasm showed positive anti-von Hippel-Lindau antibody staining, whereas the epithelium of the PanIN showed negative staining. A serous cystic neoplasm coexisting with another pancreatic neoplasm is rare. When dilatation of the main or branch pancreatic ducts coexists with a serous cystic neoplasm, as in this case, the lesion clinically mimics an intraductal papillary mucinous neoplasm.

Clinicopathological significance of Necl-4 expression in pancreatic ductal adenocarcinoma.

AIMS: The loss, or decreased expression, of nectin-like molecule 4 (Necl-4; an immunoglobulin-like cell adhesion molecule) is reported to be associated with the development and progression of certain types of cancer. We investigated the clinicopathological significance of Necl-4 expression in patients with pancreatic ductal adenocarcinoma (PDAC). METHODS: Immunohistochemical analyses of Necl-4 (n=258) and E-cadherin (n=256) expression were performed using tissue microarray blocks of PDAC samples. Necl-4 expression of 38 pancreatic intraepithelial neoplasia (PanIN) lesions included in tissue microarray cores was also evaluated. Necl-4 and E-cadherin expression was considered positive if >30% of cells were stained, and negative if ≤30% of cells were stained. RESULTS: Necl-4 expression was positive in 45.7% (n=118) and negative in 54.3% (n=140) of PDAC cases. Necl-4 staining was positive in 96.7% (n=29) and negative in 3.3% (n=1) of low-grade PanIN cases, and positive in 62.5% (n=5) and negative in 37.5% (n=3) of high-grade PanIN cases. The number of cases with positive Necl-4 expression decreased in the order low-grade PanIN>high-grade PanIN>PDAC (p<0.001). Negative Necl-4 expression was significantly associated with a larger tumour size of >30 mm, perineural invasion, lymphatic involvement, lymph node metastasis (pN1), an advanced TNM (tumour, node, metastases) stage (stage IIB-IV), an advanced histological grade (G2/3), and shorter overall survival. E-cadherin staining was positive in 46.1% (n=118) and negative in 53.9% (n=138) of PDAC cases. Necl-4 expression correlated positively with E-cadherin expression (r=0.405, p<0.001). CONCLUSIONS: The results suggest that Necl-4 is associated with carcinogenesis and aggressiveness of PDAC.

Endogenous reactive oxygen species cause astrocyte defects and neuronal dysfunctions in the hippocampus: a new model for aging brain.

The etiology of astrocyte dysfunction is not well understood even though neuronal defects have been extensively studied in a variety of neuronal degenerative diseases. Astrocyte defects could be triggered by the oxidative stress that occurs during physiological aging. Here, we provide evidence that intracellular or mitochondrial reactive oxygen species (ROS) at physiological levels can cause hippocampal (neuronal) dysfunctions. Specifically, we demonstrate that astrocyte defects occur in the hippocampal area of middle-aged Tet-mev-1 mice with the SDHCV69E mutation. These mice are characterized by chronic oxidative stress. Even though both young adult and middle-aged Tet-mev-1 mice overproduced MitoSOX Red-detectable mitochondrial ROS compared to age-matched wild-type C57BL/6J mice, only young adult Tet-mev-1 mice upregulated manganese and copper/zinc superoxide dismutase (Mn- and Cu/Zn-SODs) activities to eliminate the MitoSOX Red-detectable mitochondrial ROS. In contrast, middle-aged Tet-mev-1 mice accumulated both MitoSOX Red-detectable mitochondrial ROS and CM-H2 DCFDA-detectable intracellular ROS. These ROS levels appeared to be in the physiological range as shown by normal thiol and glutathione disulfide/glutathione concentrations in both young adult and middle-aged Tet-mev-1 mice relative to age-matched wild-type C57BL/6J mice. Furthermore, only middle-aged Tet-mev-1 mice showed JNK/SAPK activation and Ca2+ overload, particularly in astrocytes. This led to decreasing levels of glial fibrillary acidic protein and S100ß in the hippocampal area. Significantly, there were no pathological features such as apoptosis, amyloidosis, and lactic acidosis in neurons and astrocytes. Our findings suggest that the age-dependent physiologically relevant chronic oxidative stress caused astrocyte defects in mice with impaired mitochondrial electron transport chain functionality.

Bone morphogenetic protein-2 expression in an intraductal papillary mucinous neoplasm with marked ossification: A case report.

Intratumoral ossification has been reported in a number of epithelial tumors, but its presence in intraductal papillary mucinous neoplasms (IPMNs) is very rare. Herein, we present a rare case of IPMN with marked ossification. A 56-year-old Japanese man was under follow-up for a previously diagnosed IPMN. Seven years later, he was found to have dilatation of the main pancreatic duct and an enlarged solid mass, for which pancreaticoduodenectomy was performed. Macroscopically, multiple and cystically dilated pancreatic branch ducts, as well as a dilated main pancreatic duct, were identified. There was a solid, polypoid hard mass measuring 15 × 12 mm in the cystically dilated branch of the duct in the pancreatic head. Histological examination revealed papillary proliferation of atypical cuboidal or columnar epithelial cells in the dilated main and branch pancreatic ducts. The solid mass included an invasive adenocarcinoma component with a tubular or trabecular structure that showed pronounced ossification. We diagnosed the patient with invasive IPMN accompanied by marked ossification. Immunohistochemically, tumor cells in both the non-invasive and invasive lesions expressed bone morphogenetic protein-2 (BMP-2). While the mechanism of intratumoral ossification is unclear, it may have involved BMP-2 in the present case.

Molecular alterations in sporadic pancreatic neuroendocrine microadenomas.

BACKGROUND: Pancreatic neuroendocrine microadenomas (pNEMAs) are neuroendocrine tumors measuring <5 mm in diameter. They are considered the precursor of pancreatic neuroendocrine tumors (pNETs). The aim of this study was to investigate the immunohistochemical differences between pNEMA, pNET, and hyperplasia of pancreatic islet cells (HPIL) in patients with non-familial syndromes. METHODS: We evaluated 21 pNEMAs, 19 HPILs, and 21 non-functional pNETs (10 G1 and 11 G2 cases) in patients with non-familial syndromes. Immunohistochemistry for tumor-associated markers death domain-associated protein (DAXX), alpha thalassemia/mental retardation X-linked (ATRX), cytokeratin 19 (CK19), bcl-2, and CD99 was performed. RESULTS: DAXX was expressed in 95%, 71%, and 71% of HPIL, pNEMA, and pNET samples, respectively; the differences were not significant. ATRX expression in pNEMA and pNET was significantly lower than that in HPIL, whereas there was no significant difference between pNEMA and pNET (HPIL: 95%, pNEMA: 43%, and pNET: 52%). All HPIL and pNEMA cases were negative for bcl-2 and positive for CD99, whereas 29% of pNETs were positive for bcl-2 and 24% were negative for CD99. CK19 expression in HPIL was significantly lower than in pNEMA and pNET, although no significant difference was observed between pNEMA and pNET (HPIL: 5%, pNEMA: 57%, and pNET: 43%). Among G1 and G2 pNETs, CD99 was expressed in 50% of G1 pNETs but not in any G2 pNET cases. CONCLUSION: Non-familial HPIL, pNEMA, and pNET patients exhibit distinct ATRX, CD99, CK19, and bcl-2 molecular profiles.

Genetically induced oxidative stress in mice causes thrombocytosis, splenomegaly and placental angiodysplasia that leads to recurrent abortion.

Historical data in the 1950s suggests that 7%, 11%, 33%, and 87% of couples were infertile by ages 30, 35, 40 and 45, respectively. Up to 22.3% of infertile couples have unexplained infertility. Oxidative stress is associated with male and female infertility. However, there is insufficient evidence relating to the influence of oxidative stress on the maintenance of a viable pregnancy, including pregnancy complications and fetal development. Recently, we have established Tet-mev-1 conditional transgenic mice, which can express the doxycycline-induced mutant SDHC(V69E) transgene and experience mitochondrial respiratory chain dysfunction leading to intracellular oxidative stress. In this report, we demonstrate that this kind of abnormal mitochondrial respiratory chain-induced chronic oxidative stress affects fertility, pregnancy and delivery rates as well as causes recurrent abortions, occasionally resulting in maternal death. Despite this, spermatogenesis and early embryogenesis are completely normal, indicating the mutation's effects to be rather subtle. Female Tet-mev-1 mice exhibit thrombocytosis and splenomegaly in both non-pregnant and pregnant mice as well as placental angiodysplasia with reduced Flt-1 protein leading to hypoxic conditions, which could contribute to placental inflammation and fetal abnormal angiogenesis. Collectively these data strongly suggest that chronic oxidative stress caused by mitochondrial mutations provokes spontaneous abortions and recurrent miscarriage resulting in age-related female infertility.