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Abstract Background Ductal carcinoma in situ (DCIS) of the breast constitutes a heterogeneous group of non-obligate precursors for invasive breast cancer. To date, adequate risk stratification is lacking, which is presumed to result in overtreatment. We previously identified myxoid stromal architecture as a potential prognosticator for loco-regional recurrence. In the present study, we investigated the prognostic potential of stromal characteristics. Methods Hematoxylin and eosin stained slides from 211 DCIS patients were reviewed. The following histological features were dichotomously assessed: nuclear grade, DCIS architecture, presence of necrosis, intraductal calcifications, stromal inflammation and myxoid stromal architecture. Loco-regional recurrences constituted the primary endpoint. Results: Cox regression analysis showed that high nuclear grade, myxoid stromal architecture and moderate to extensive stromal inflammation were significantly associated with decreased recurrence-free survival, independent of radiotherapy. Based on these features, a combined risk score (CRS) was calculated, ranging from zero to three. A high CRS of three was associated with significantly shorter recurrence-free survival. Nineteen patients had a CRS of three, of which three relapsed (15.7%), whereas only one out of 113 patients with a CRS of zero relapsed (0.9%). Conclusions We were able to validate our previously reported findings regarding the prognostic potential of myxoid periductal stroma in an independent DCIS patient cohort. A CRS based on nuclear grade, myxoid stromal architecture and stromal inflammation might facilitate discrimination of low risk from high risk patients. Consequently, the CRS may tailor adjuvant therapy. Future research should investigate whether radiotherapy can be safely omitted in patients with a low CRS. [ABSTRACT FROM AUTHOR]

This viewpoint is a personal reflection on the values and merits of immunohistochemistry in current breast cancer diagnosis. Immunohistochemistry is a validated mainstay in molecular subtyping of invasive breast cancer. Immunohistochemical assessment of hormone receptor status and HER2 expression is used to determine the clinico-pathological surrogate of breast cancer intrinsic subtypes, which guide neoadjuvant and adjuvant therapy. The advent of genomic prognostic signatures and qualitative mRNA-based assays makes some clinicians and researchers wonder whether immunohistochemistry should be abandoned. However, the perils and pitfalls of these mRNA-based tests cannot be neglected. This viewpoint offers a brief overview of quality issues in immunohistochemistry and qPCR, as well as a concise summary of currently available evidence on the correlation of immunohistochemistry and mRNA-based testing for prognostic and predictive markers in invasive breast cancer. We strongly advocate the use of immunohistochemistry as it integrates valuable spatial information with quantification of protein expression. [ABSTRACT FROM AUTHOR]

Abstract: Background: Non-alcoholic fatty liver disease is a spectrum of disorders ranging from steatosis to non-alcoholic steatohepatitis (NASH). Steatosis of the liver is benign, whereas NASH can progress to cirrhosis or even hepatocellular carcinoma. Currently, a liver biopsy is the only validated method to distinct NASH from steatosis. Aim: The objective of this study was to identify a biomarker specific for NASH based on the N-glycosylation of serum proteins. Methods: N-glycosylation patterns were assessed using DNA sequencer-assisted fluorophore-assisted capillary electrophoresis and compared with histology. Results: Initially, a glycomarker (log[NGA2F]/[NA2]) was developed based on the results obtained in 51 obese non-alcoholic patients scheduled for bariatric surgery. Multivariate analysis showed that our glycomarker had the lowest P-value of all biomarkers in distinguishing NASH from steatosis (P =0.069). The glycomarker was validated in a cohort of 224 non-alcoholic fatty liver disease patients. In both pilot and validation study, glycomarker score increased in ascending amount of lobular inflammation (single-factor ANOVA, P ≤0.001 and P =0.012, respectively). The N-glycan profile of immunoglobulin G in the NASH population confirmed the significantly increased undergalactosylation present in these patients. Conclusion: Our glycomarker specifically recognises liver inflammation in obese individuals which is the main trigger for the development of steatohepatitis and can differentiate between steatosis and NASH. [Copyright &y& Elsevier]

Background & Aims: The human liver-uPA+/+-SCID mouse is currently the best small animal model available for viral hepatitis infection studies. Methods: We identify critical factors affecting animal survival, engraftment efficacy, kinetics of liver repopulation and virological outcome by analysing the data from 400 human hepatocyte transplantations and 115 subsequent HBV and/or HCV inoculations in this mouse model. Results: Almost one third of animals succumbed during the first week after hepatocyte transplantation. Only during this critical period, liver necrosis due to embolization of donor cells in the portal vein was observed. This may have caused a fatal acute liver failure that complicated the pre-existing chronic liver disease. From the second week onwards, confluent hepatocyte clusters repopulated the liver and restored its synthetic functions as evidenced by increasing human albumin levels in plasma. Xenogenic repopulation by human cells proceeded approximately 4-times slower compared to allogenic mouse hepatocytes. All HBV inoculations were successful, even in animals with low graft take. HCV infection rate varied substantially, although every donor cell type yielded infectable animals. A reproducible 100% HCV infectivity was reached with high quality inocula in animals with human albumin plasma levels >1mg/ml. Superior animal survival, adequate liver engraftment and a high viral infection rate were observed after transplanting cryopreserved commercial human hepatocytes. Conclusions: Our findings favour the use of commercially available, cryopreserved human hepatocytes for the humanization of the uPA+/+-SCID liver. While HBV infectivity criteria are less stringent, human albumin plasma levels exceeding 1mg/ml are required for a consistent HCV infection in chimeric mice. [ABSTRACT FROM AUTHOR]

The development of hepatocellular adenomas and – more rarely – carcinoma in the liver of patients with Glycogen Storage Disease type Ia (GSDIa) is a well-known complication of the disease. The pathophysiology of adenoma and carcinoma development in these patients is, however, hitherto largely unknown and is thought to be related to the metabolic control of the patient and/or the type of mutations in the G6PC gene. We report here on a very illustrative case of adenoma and carcinoma formation in a previously undiagnosed 42year old male GSDIa patient (enzymatically and genetically proven). He had two episodes of mild hypoglycaemia in childhood, never required formal treatment, showed normal growth, and only mild lactate increases after prolonged starvation. He was a long-distance runner for most of his adult life, without the need for more than normal carbohydrate intake before/during exertion. To gain a better view on the type of adenoma formed in this patient, molecular studies were performed. We show here that in this patient with mild GSDIa without recurrent hypoglycaemic episodes, adenoma and carcinoma formation still occurred and that malignant transformation of adenoma here is associated with CTNNB1 mutations and a typical mRNA profile of a β-catenin activated lesion. [Copyright &y& Elsevier]

Abstract: In this study, the prognostic and/or predictive value of different proteins (cyclo-oxygenase 2 (COX-2), Ki67 and cleaved cytokeratin (CK) 18) and fibro-inflammatory changes which might be of importance for the response to treatment were evaluated using tissue micro arrays. Samples were obtained from a subset of 95 patients included in the European Organisation for Research and Treatment of Cancer 22921 clinical trial, which randomised patients with rectal cancer to one of four arms treated with preoperative radiotherapy with or without pre- and/or postoperative chemotherapy. From our results, we can conclude that the addition of preoperative chemotherapy to radiotherapy led to significantly less COX-2 upregulation, less proliferation and more inflammation, as was seen in the resection specimen as well as less invasion and metastasis. For COX-2, Ki67 or cleaved CK18, no predictive or prognostic value could be identified. However, the fibro-inflammatory reaction after preoperative radiochemotherapy correlated with T-downstaging and seems to be an important factor for response. [Copyright &y& Elsevier]

Background & Aims: The Rho small guanosine triphosphatase Cdc42 is critical for diverse cellular functions, including regulation of actin organization, cell polarity, intracellular membrane trafficking, transcription, cell-cycle progression, and cell transformation. This implies that Cdc42 might be required for liver function. Methods: Mice in which Cdc42 was ablated in hepatocytes and bile duct cells were generated by Cre-loxP technology. Livers were examined by histologic, immunohistochemical, ultrastructural, and serum analysis to define the effect of loss of Cdc42 on liver structure. Results: Mice lacking Cdc42 in their hepatocytes were born at Mendelian ratios. They did not show increased mortality but showed chronic jaundice. They developed hepatomegaly soon after birth, and signs of liver transformation, such as formation of nodules and tumors, became visible macroscopically at age 6 months. Hepatocellular carcinoma was observed 8 months after birth. Tumors grew slowly and lacked expression of nuclear β-catenin. Lung metastases were observed at the late stage of carcinogenesis. Immunofluorescent examination and electron microscopy revealed severe defects in the liver. At the age of 2 months, the canaliculi between hepatocytes were greatly enlarged, although the tight junctions flanking the canaliculi appeared normal. Regular liver plates were absent. E-cadherin expression pattern and gap junction localization were distorted. Analysis of serum samples indicated cholestasis. Conclusions: We describe a mouse model in which chronic liver disease leads to hepatocarcinogenesis. [Copyright &y& Elsevier]

The finding of a focal solid liver lesion represents a challenge for the clinician in terms of the most optimal diagnostic and therapeutic algorithm. Tumours may arise from hepatocytes (hepatocellular adenoma, dysplastic nodules and carcinoma), bile ducts (cholangiocarcinoma) or mesenchymal tissue (hemangioma, epithelioid haemangioendothelioma), or are metastases from primary tumours outside the liver. Focal nodular hyperplasia is the most frequent tumour-like lesion. Imaging techniques are able to detect and characterise most lesions. However, small hypervascular lesions in a cirrhotic liver may be difficult to characterise. More insight has been gathered recently in the histological classification of hepatocellular adenomas, but the differential diagnosis by imaging of adenoma versus FNH or well-differentiated hepatocellular carcinoma remains often difficult. The therapy of a focal liver lesion is determined by its natural history and the functional status of the surrounding liver parenchyma. Selected patients with primary liver cancer are candidates for liver transplantation, while patients with advanced malignant tumours have a poor outcome. [Copyright &y& Elsevier]

Background & Aims: Because current therapies for chronic hepatitis C virus (HCV) infections are suboptimal and associated with severe side effects, novel treatment options are needed. A small animal model has recently been developed to study HCV infections. To examine the usefulness of this human liver–urokinase-type plasminogen activator (uPA)+/+ severe combined immune deficient (SCID) mouse for the development of HCV-targeted drugs, we evaluated the antiviral efficacy and safety of an HCV NS3-protease inhibitor, BILN 2061. Methods: BILN 2061 was orally administered at clinical range doses for 4 days to SCID mice that differed in the presence of HCV infection, human hepatocyte grafts, and uPA zygosity. Treatment outcome was evaluated clinically, virologically, and morphologically. Using standard high-performance liquid chromatography–ultraviolet (HPLC-UV) methods and mass spectrometry, single-dose pharmacokinetics and multiple-dose drug exposures were analyzed. The 13C-aminopyrine breath test was applied to compare in vivo liver function. Results: A 4-day treatment with BILN 2061 of HCV genotype-1b infected chimeric animals reduced the viral load by >100-fold, but concomitant clinical and ultrastructural signs of cardiotoxicity appeared. BILN 2061 administration to uPA-transgenic mice induced mitochondrial swelling with aberrant cristae in cardiomyocytes, but not in skeletal muscle. Because both drug accumulation and liver function were identical in affected uPA-transgenic and nontransgenic SCID mice without cardiac involvement, the urokinase plasminogen activator transgene itself appears to be implicated. Conclusions: The human liver-uPA+/+SCID mouse is an interesting small animal model to evaluate the preclinical safety and efficacy of new antiviral compounds against HCV. The uPA-transgene increases the susceptibility of mice to BILN 2061-induced cardiotoxicity. [Copyright &y& Elsevier]

Background/Aims: Hepatic stellate cells (HSC) are commonly considered the precursor population of septal myofibroblasts (MF) in cirrhosis. We studied the distribution and expression profile of mesenchymal (myo)fibroblast-like populations in fibrotic and cirrhotic liver, in an attempt to elucidate their possible interrelationships.Methods: Fibrotic/cirrhotic livers (from 22 human explants and from two rat models: carbon tetrachloride intoxication, bile duct-ligation) were studied by means of immunohistochemistry (single and double immunostaining) with antibodies raised against desmin, alpha-smooth muscle actin (αSMA), glial fibrillary acidic protein (GFAP), neural-cell adhesion molecule (N-CAM), synaptophysin, neurotrophins, neurotrophin receptors and alpha B-crystallin (ABCRYS).Results: Septal MF showed the same expression profile as portal MF, in human and rat, being αSMA/ABCRYS/brain-derived nerve growth factor/GFAP-expression, with additional N-CAM- and desmin-expression in rat portal/septal MF. Perisinusoidally located HSC stained with all tested markers, MF at the septal/parenchymal interface showed an expression profile, intermediate between the profiles of HSC and portal/septal MF.Conclusions: In advanced fibrosis and in cirrhosis, regardless of cause or species, three distinct mesenchymal (myo)fibroblast-like liver cell subpopulations can be discerned: portal/septal MF, interface MF and perisinusoidally located HSC. The fact that septal MF share more characteristics with portal MF than with HSC might suggest descent. [Copyright &y& Elsevier]

Intramuscular myxoma is a soft tissue myxoid tumor with a broad morphological differential diagnosis and recent developments have led to the identification of markers that can exclude some, but not all, differential diagnostic entities. However, a sensitive confirmatory marker for intramuscular myxoma has not been clearly identified. Since there is some evidence that mutations in the GNAS gene could be such a marker, we evaluated our results of next-generation sequencing testing for GNAS mutations performed in recent years on our series of intramuscular myxoma. Next-generation sequencing was performed on 10 cases of intramuscular myxoma diagnosed between 2015 and 2019, using either the TruSight Tumor 26 panel or an in-house developed 97 cancer gene panel. Additionally, immunohistochemistry for CD34 was performed on all cases. All intramuscular myxomas showed a diffuse and strong expression of CD34 and a GNAS mutation was found in 88% of cases, making this a very sensitive positive test for the diagnosis of intramuscular myxoma. Under the condition that contemporary next-generation sequencing is applied as testing method, searching for GNAS mutations is a very sensitive confirmatory test for the diagnosis of intramuscular myxoma, obviating the necessity to perform tests that exclude other entities by the virtue of their negative result. The molecular tests results also identified strong and diffuse CD34 expression as a sensitive, albeit non-specific, marker for intramuscular myxoma. • Searching for GNAS mutations is a very sensitive positive molecular test for the diagnosis of intramuscular myxoma. • GNAS mutation testing obviates the necessity to perform multiple other tests that exclude similar entities by virtue of their negative result. • The high sensitivity of GNAS mutation testing for intramuscular myxoma is only obtained when using contemporary next-generation sequencing [ABSTRACT FROM AUTHOR]

Background/Aims: Focal nodular hyperplasias (FNHs) are benign liver lesions considered to be a hyperplastic response to increased blood flow in normal liver. In contrast, FNH-like lesions/nodules occur in cirrhotic liver but share similar histopathological features. We conducted a transcriptome analysis to identify biological pathways deregulated in FNH. Methods: Gene expression profiles obtained in FNH and normal livers were compared. Differentially-expressed genes were validated using quantitative-RT-PCR in 70 benign liver tumors including FNH-like lesions. Results: Among the deregulated genes in FNHs, 19 displayed physiological restricted distribution in the normal liver. All six perivenous genes were up-regulated in FNH, whereas 13 periportal genes were down-regulated. Almost all these genes are known to be regulated by β-catenin. Glutamine synthetase was markedly overexpressed in anastomosed areas usually centered on visible veins. Moreover, activated hypophosphorylated β-catenin protein accumulated in FNH in the absence of activating mutations. These results suggest the zonated activation of the β-catenin pathway in FNH, whereas the other benign hepatocellular tumors, including FNH-like lesions, demonstrated an entirely different pattern of β-catenin expression. Conclusions: In FNH, increased activation of the β-catenin pathway was found restricted to enlarged perivenous areas. FNH-like nodules may have a different pathogenetic origin. [Copyright &y& Elsevier]

Abstract: Hepatitis virus replication in the liver is often accompanied by inflammation resulting in the formation of reactive oxygen species (ROS) and nitric oxide (NO) and these may induce cell death. We investigated whether the expression of HBx or HCV core protein in HepG2 cells has an influence on the sensitivity of these cells for oxidative radicals. Our previous study, using the inducible HBV model of HepAD38, revealed that oxidative-stress-related genes are upregulated by virus replication. In the present study, we examined the intracellular pro-oxidant status with dichlorofluorescein (DCF) in HepG2 cell lines transfected with HBx, HbsAg and HCV core. Baseline intracellular oxidative levels were not different in the cell lines expressing viral proteins as compared to control. However, when these cells were exposed to H2O2, the viral protein expressing cells, especially those expressing HBx, showed a reduced level of ROS. This suggests that HBx and HCV core transfected cells can convert H2O2 to less reactive compounds at a higher rate than the control cells. When HBx or HCV core expressing cells were exposed to peroxynitrite (a highly reactive product formed under physiological conditions through interaction of superoxide (O2 − ) these cells were less sensitive to induction of cell death. In addition, these cell lines were less prone to cell death when exposed to H2O2 directly. In conclusion, HBx and HCV core expression in HepG2 cells leads to a survival benefit under oxidative stress which in vivo can be induced during inflammation. [Copyright &y& Elsevier]

p120 catenin (p120ctn) is required for the stability of classic cadherins at the cell surface and is thought to play a central role in modulating cell–cell adhesion. Cytoplasmic p120ctn promotes cell motility, and probably other activities, by modulating the activities of RhoA, Rac and Cdc42. E-cadherin is expressed in periportal but not in perivenous hepatocytes. In contrast, all hepatocytes of normal mouse liver express N-cadherin. Cholangiocytes express exclusively E-cadherin. Mice with p120ctn ablation in hepatocytes and cholangiocytes (p120LiKO mice) were generated by Cre- lox P technology. Livers were examined by histological, immunohistochemical, ultrastructural and serum analysis to determine the effect of the p120ctn ablation on liver structure and function. Mouse hepatocyte differentiation and homeostasis were not impaired. However, hepatoblasts differentiated abnormally into hybrid hepato-biliary cells, ductal plate structures were irregular in p120LiKO newborns, and further development of intrahepatic bile ducts was severely impaired. In adults, enrichment of ductular structures was accompanied by portal inflammation and fibrosis. p120LiKO mice did not spontaneously develop hepatocellular carcinoma but initiation of hepatocarcinogenesis by diethylnitrosamine was accelerated. In summary: p120ctn has a critical role in biliary differentiation and is a potent suppressor of liver tumor growth. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to investigate the effect of genetic polymorphisms in miRNA sequences, miRNA target genes and miRNA processing genes as additional biomarkers to HPV for prognosis in oropharyngeal squamous cell carcinoma (OPSCC) patients. Secondarily, the prevalence of HPV-associated OPSCC in a European cohort was mapped.Methods: OPSCC patients (n=122) were genotyped for ten genetic polymorphisms in pre-miRNAs (pre-mir-146a, pre-mir-196a2), in miRNA biosynthesis genes (Drosha, XPO5) and in miRNA target genes (KRAS, SMC1B). HPV status was assessed by p16 immunohistochemistry (IHC) and high-risk HPV in situ hybridization (ISH) or by p16 IHC and PCR followed by enzyme-immunoassay (EIA). Overall and disease specific survival were analysed using Kaplan-Meier plots (log-rank test). Cox proportional hazard model was used to calculate hazard ratios (HR).Results: The overall HPV prevalence rate in our Belgian/Dutch cohort was 27.9%. Patients with HPV(+) tumours had a better 5-years overall survival (78% vs. 46%, p=0.001) and a better 5-years disease specific survival (90% vs. 70%, p=0.016) compared to patients with HPV(-) tumours. In multivariate Cox analysis including clinical, treatment and genetic parameters, HPV negativity (HR=3.89, p=0.005), advanced T-stage (HR=1.81, p=0.050), advanced N-stage (HR=5.86, p=0.001) and >10 pack-years of smoking (HR=3.45, p=0.012) were significantly associated with reduced overall survival. The variant G-allele of the KRAS-LCS6 polymorphism was significantly associated with a better overall survival (HR=0.40, p=0.031).Conclusions: Our results demonstrate that OPSCC patients with the KRAS-LCS6 variant have a better outcome and suggest that this variant may be used as a prognostic biomarker for OPSCC. [ABSTRACT FROM AUTHOR]

Background & Aims: Hepatocellular adenomas (HCA) are benign liver tumors mainly related to oral contraception and classified into 4 molecular subgroups: inflammatory (IHCA), HNF1A-inactivated (H-HCA), β-catenin-activated (bHCA) or unclassified (UHCA). Glycogen storage disease type I (GSD) is a rare hereditary metabolic disease that predisposes to HCA development. The aim of our study was to characterize the molecular profile of GSD-associated HCA. Methods: We characterized a series of 25 HCAs developed in 15 patients with GSD by gene expression and DNA sequence of HNF1A, CTNNB1, IL6ST, GNAS, and STAT3 genes. Moreover, we searched for glycolysis, gluconeogenesis, and fatty acid synthesis alterations in GSD non-tumor livers and compared our results to those observed in a series of sporadic H-HCA and various non-GSD liver samples. Results: GSD adenomas were classified as IHCA (52%) mutated for IL6ST or GNAS, bHCA (28%) or UHCA (20%). In contrast, no HNF1A inactivation was observed, showing a different molecular subtype distribution in GSD-associated HCA from that observed in sporadic HCA (p= 0.0008). In non-tumor GSD liver samples, we identified glycolysis and fatty acid synthesis activation with gluconeogenesis repression. Interestingly, this gene expression profile was similar to that observed in sporadic H-HCA. Conclusions: Our study showed a particular molecular profile in GSD-related HCA characterized by a lack of HNF1A inactivation. This exclusion could be explained by similar metabolic defects observed with HNF1A inactivation and glucose-6-phosphatase deficiency. Inversely, the high frequency of β-catenin mutations could be related to the increased frequency of malignant transformation in hepatocellular carcinoma. [ABSTRACT FROM AUTHOR]

Background & Aims: The placental growth factor (PlGF) is a member of the vascular endothelial growth factor (VEGF) family known to stimulate endothelial cell growth, migration and survival, attract angiocompetent macrophages, and determine the metastatic niche. Unlike VEGF, genetic studies have shown that PlGF is specifically involved in pathologic angiogenesis, thus its inhibition would not affect healthy blood vessels, providing an attractive drug candidate with a good safety profile. Methods: We assess whether inhibition of PlGF could be used as a potential therapy against hepatocellular carcinoma (HCC), by using PlGF knockout mice and monoclonal anti-PlGF antibodies in a mouse model for HCC. In addition, the effect of PlGF antibodies is compared to that of sorafenib, as well as the combination of both therapies. Results: We have found that both in a transgenic knockout model and in a treatment model, targeting PlGF significantly decreases tumor burden. This was achieved not only by inhibiting neovascularisation, but also by decreasing hepatic macrophage recruitment and by normalising the remaining blood vessels, thereby decreasing hypoxia and reducing the prometastatic potential of HCC. Conclusions: Considering the favourable safety profile and its pleiotropic effect on vascularisation, metastasis and inflammation, PlGF inhibition could become a valuable therapeutic strategy against HCC. [ABSTRACT FROM AUTHOR]

Background & Aims: The two major primary liver cancers in adults are hepatocellular carcinoma and cholangiocarcinoma. These tumors rapidly outgrow their vascular supply and become hypoxic, resulting in the production of hypoxia inducible factors. Recently, interest has grown in the regulators of these factors. Several reports have been published describing the role of prolyl hydroxylase domains – the key oxygen sensor responsible for the degradation of hypoxia inducible factors – in tumor progression and vascularisation. The effect of prolyl hydroxylase domain 2 on the pathogenesis of liver cancer has never been studied. Methods: A diethylnitrosamine-induced mouse model was used in this study, allowing primary hepatic tumors to occur as a result of chronic liver damage. Several parameters of prolyl hydroxylase domain 2-haplodeficient mice were compared to those of wild type mice, thereby focussing on the expression of angiogenic factors and on the hepatic progenitor cell activation and differentiation. Results: This study shows that inhibiting prolyl hydroxylase domain 2 increases the hepatocarcinogenesis and stimulates the development of cholangiocarcinoma. Furthermore, PHD2 deficiency and the accompanying continuous HIF activation, selected for a more metastatic tumor phenotype. Conclusions: The effect of prolyl hydroxylase domain 2 deficiency on hepatocarcinogenesis hold a great potential for therapeutic intervention, since hypoxia and the selection for a more aggressive cholangiocarcinoma phenotype might also have a repercussion on patients receiving long-term treatment with anti-angiogenic compounds. [Copyright &y& Elsevier]

Abstract: Purpose: To assess the feasibility and efficacy of the COX-2 inhibitor celecoxib in conjunction with preoperative chemoradiation for patients with locally advanced rectal cancer in a double blind randomized phase II study. Materials and methods: Thirty-five patients of the initially planned 80 patients with locally advanced rectal cancer were treated with preoperative radiation (45Gy; 1.8Gy/fraction, 5days/week) combined with 5-fluorouracil (continuous infusion, 225mg/m2/day) and celecoxib (2×400mg/day) or placebo. Pathological response and toxicity of study treatment were evaluated, as well as expression of COX-2 and Ki67 in tumor tissue and IL-6 in plasma as possible molecular correlates and predictors of response to treatment. Results: Patients treated with celecoxib tended to show a better response (61%) when compared to those treated with placebo (35%), although not significant (p= 0.13). T-downstaging and N-downstaging were also slightly higher with celecoxib. Plasma IL-6 levels and intratumoral COX2 or Ki67 were altered by chemoradiation, but were not further altered by celecoxib treatment and therefore not useful for prediction of treatment benefit. Celecoxib therapy in conjunction with chemoradiation was not associated with additional toxicity and seemed to help mitigate therapy-related pain. Conclusions: Addition of celecoxib to preoperative chemoradiation is feasible for patients with locally advanced rectal cancer. To study the individual effect of COX-2 inhibitors on pathological response phase III studies are required. [Copyright &y& Elsevier]

MRP1 (multidrug resistance-associated protein 1) is well known for its role in providing multidrug resistance to cancer cells. In addition, MRP1 has been associated with both pro- and anti-inflammatory functions in nonmalignant cells. The pro-inflammatory function is evident from the fact that MRP1 is a high affinity transporter for cysteinyl-leukotriene C4 (LTC4), a lipid mediator of inflammation. It remains unexplained, however, why the absence of Mrp1 leads to increased intestinal epithelial damage in mice treated with dextran-sodium sulfate, a model for inflammatory bowel disease (IBD). We found that MRP1 expression is induced in the inflamed intestine of IBD patients, e.g. Crohn disease and ulcerative colitis. Increased MRP1 expression was detected at the basolateral membrane of intestinal epithelial cells. To study a putative role for MRP1 in protecting epithelial cells against inflammatory cues, we manipulated MRP1 levels in human epithelial DLD-1 cells and exposed these cells to cytokines and anti-Fas. Inhibition of MRP1 (by MK571 or RNA interference) resulted in increased cytokine- and anti-Fas-induced apoptosis of DLD-1 cells. Opposite effects, e.g. protection of DLD-1 cells against cytokine- and anti-Fas-induced apoptosis, were observed after recombinant MRP1 overexpression. Inhibition of LTC4 synthesis reduced anti-Fas-induced apoptosis when MRP1 function was blocked, suggesting that LTC4 is the pro-apoptotic compound exported by epithelial MRP1 during inflammation. These data show that MRP1 protects intestinal epithelial cells against inflammation-induced apoptotic cell death and provides a functional role for MRP1 in the inflamed intestinal epithelium of IBD patients. [ABSTRACT FROM AUTHOR]