359 research outputs found

    miR-25 targets TNF-related apoptosis inducing ligand (TRAIL) death receptor-4 and promotes apoptosis resistance in cholangiocarcinoma.

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    It has been established that microRNA expression and function contribute to phenotypic features of malignant cells, including resistance to apoptosis. Although targets and functional roles for a number of microRNAs have been described in cholangiocarcinoma, many additional microRNAs dysregulated in this tumor have not been assigned functional roles. In this study, we identify elevated miR-25 expression in malignant cholangiocarcinoma cell lines as well as patient samples. In cultured cells, treatment with the Smoothened inhibitor, cyclopamine, reduced miR-25 expression, suggesting Hedgehog signaling stimulates miR-25 production. Functionally, miR-25 was shown to protect cells against TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. Correspondingly, antagonism of miR-25 in culture sensitized cells to apoptotic death. Computational analysis identified the TRAIL Death Receptor-4 (DR4) as a potential novel miR-25 target, and this prediction was confirmed by immunoblot, cell staining, and reporter assays. CONCLUSION: These data implicate elevated miR-25 levels in the control of tumor cell apoptosis in cholangiocarcinoma. The identification of the novel miR-25 target DR4 provides a mechanism by which miR-25 contributes to evasion of TRAIL-induced cholangiocarcinoma apoptosis

    A case of distal extrahepatic cholangiocarcinoma with two positive resection margins

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    Cholangiocarcinoma is an uncommon primary malignancy of the biliary tract that is challenging to diagnose and treat effectively due to its relatively silent and late clinical presentation. The present study reports a case of a 60-year-old male with distal extrahepatic cholangiocarcinoma with a 3-week history of painless obstructive jaundice symptoms and subjective weight loss. Imaging revealed an obstructing lesion in the common bile duct, just distal to the entrance of the cystic duct. Pathology revealed moderately differentiated cholangiocarcinoma with two positive proximal resection margins. The two positive resection margins presented a challenge during surgery and points to an urgent need for further studies to better illuminate diagnostic and therapeutic options for patients with similar clinicopathological presentation

    Hedgehog Signaling Modulates Interleukinâ 33â Dependent Extrahepatic Bile Duct Cell Proliferation in Mice

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147852/1/hep41295_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147852/2/hep41295.pd

    The true prognosis of resected distal cholangiocarcinoma

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    International audienceBACKGROUND: Prognosis of distal cholangiocarcinoma (DCC) after pancreaticoduodenectomy (PD) remains poorly assessed. The aims of this study were to describe the oncological results of PD in DCC and to compare its prognosis to pancreatic ductal adenocarcinoma (PDAC). METHODS: All PD for periampullary carcinoma performed between January 2000 and March 2013 were extracted from a prospective database. Risk factors likely to influence overall (OS) and disease-free (DFS) survivals of DCC were assessed by multivariable analyses. The DCC and PDAC prognoses were compared after matching using propensity score (nearest neighbor matching). RESULTS: Of the 290 patients analyzed, 56 had DCC, with a mean age of 65 ± 15 years. The median OS was 36.9 months. Recurrence occurred in 35 patients (67%), mostly in the liver (37%). The median DFS was 14.6 months. Combined organ resection was an independent risk factor for worse OS and DFS (P = 0.01 and P = 0.001, respectively). Matching analysis found no significant difference between DCC and PDAC in terms of OS (P = 0.284) or DFS (P = 0.438). CONCLUSION: This first propensity analysis demonstrated that DCC and PDAC have the same prognosis, linked to the high rate of early recurrence, particularly associated with the need for combined organ resection. J. Surg. Oncol. © 2016 Wiley Periodicals, In

    A nomogram incorporating six easily obtained parameters to discriminate intrahepatic cholangiocarcinoma and hepatocellular carcinoma

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    Intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC) are the most prevalent histologic types of primary liver cancer (PLC). Although ICC and HCC share similar risk factors and clinical manifestations, ICC usually bears poorer prognosis than HCC. Confidently discriminating ICC and HCC before surgery is beneficial to both treatment and prognosis. Given the lack of effective differential diagnosis biomarkers and methods, construction of models based on available clinicopathological characteristics is in need. Nomograms present a simple and efficient way to make a discrimination. A total of 2894 patients who underwent surgery for PLC were collected. Of these, 1614 patients formed the training cohort for nomogram construction, and thereafter, 1280 patients formed the validation cohort to confirm the model’s performance. Histopathologically confirmed ICC was diagnosed in 401 (24.8%) and 296 (23.1%) patients in these two cohorts, respectively. A nomogram integrating six easily obtained variables (Gender, Hepatitis B surface antigen, Aspartate aminotransferase, Alpha‐fetoprotein, Carcinoembryonic antigen, Carbohydrate antigen 19‐9) is proposed in accordance with Akaike’s Information Criterion (AIC). A score of 15 was determined as the cut‐off value, and the corresponding discrimination efficacy was sufficient. Additionally, patients who scored higher than 15 suffered poorer prognosis than those with lower scores, regardless of the subtype of PLC. A nomogram for clinical discrimination of ICC and HCC has been established, where a higher score indicates ICC and poor prognosis. Further application of this nomogram in multicenter investigations may confirm the practicality of this tool for future clinical use.Confidently discriminating ICC and HCC before surgery can improve both treatment and prognosis. The authors have used a large‐scale study to construct a simple nomogram model incorporating six easily obtained parameters, which demonstrates high accuracy (AUC >0.85) when compared with clinical histologic examination.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142986/1/cam41341.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142986/2/cam41341_am.pd

    Perk-dependent repression of miR-106b-25 cluster is required for ER stress-induced apoptosis

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    Activation of the unfolded protein response sensor PKR-like endoplasmic reticulum kinase (Perk) attenuates endoplasmic reticulum (ER) stress levels. Conversantly, if the damage is too severe and ER function cannot be restored, this signaling branch triggers apoptosis. Bcl-2 homology 3-only family member Bim is essential for ER stress-induced apoptosis. However, the regulatory mechanisms controlling Bim activation under ER stress conditions are not well understood. Here, we show that downregulation of the miR-106b-25 cluster contributes to ER stress-induced apoptosis and the upregulation of Bim. Hypericin-mediated photo-oxidative ER damage induced Perk-dependent cell death and led to a significant decrease in the levels of miRNAs belonging to miR-106b-25 cluster in wild-type (WT) but not in Perk−/− MEFs. Further, we show that expression of miR-106b-25 and Mcm-7 (host gene of miR-106b-25) is co-regulated through the transcription factors Atf4 (activating transcription factor 4) and Nrf2 (nuclear factor-erythroid-2-related factor 2). ER stress increased the activity of WT Bim 3′UTR (untranslated region) construct but not the miR-106b-25 recognition site-mutated Bim 3′UTR construct. Overexpression of miR-106b-25 cluster inhibits ER stress-induced cell death in WT but did not confer any further protection in Bim-knockdown cells. Further, we show downregulation in the levels of miR-106b-25 cluster in the symptomatic SOD1G86R transgenic mice. Our results suggest a molecular mechanism whereby repression of miR-106b-25 cluster has an important role in ER stress-mediated increase in Bim and apoptosis
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