Expression of TNF-receptor associated factor 2 correlates with poor progression-free survival time in ABC-like primary nodal diffuse large B-cell lymphomas.

Item does not contain fulltextAIMS: Tumour necrosis factor (TNF)-receptor associated factor 2 (TRAF2) is an adaptor molecule involved in nuclear factor (NF)-kappaB activation, which is characteristic of in vitro activated B-cell (ABC)-like diffuse large B-cell lymphomas (DLBCL) and may result in expression of anti-apoptotic genes and poor response to chemotherapy. TRAF2 also has direct anti-apoptotic properties via interference with the apoptosis signalling cascade. The aim was to determine whether TRAF2 is preferentially expressed in ABC-like DLBCL, and whether expression correlates with clinical outcome. METHODS AND RESULTS: TRAF2 was expressed in nine of 20 tested ABC-like DLBCLs and in only one of 13 tested germinal centre B-lymphocyte (GCB)-like DLBCLs. High TRAF2 expression was correlated with high International Prognostic Index at time of presentation, high chance of relapse and short progression-free survival time in 44 tested DLBCLs. Furthermore, when analysis was restricted to ABC-like DLBCL only, TRAF2 expression was significantly associated with poor progression-free survival time. CONCLUSIONS: TRAF2 might be involved in activation of NF-kappaB in a subset of ABC-like DLBCL, and its expression is associated with a particularly poor outcome in primary nodal DLBCL patients. Because of its possible effect on to chemotherapy resistance, resistance, TRAF2 might be an attractive candidate as a molecular target for TRAF2+ DLBCL

Phosphorylated p-70S6K predicts tamoxifen resistance in postmenopausal breast cancer patients randomized between adjuvant tamoxifen versus no systemic treatment

Contains fulltext : 136517.pdf (publisher's version ) (Open Access)INTRODUCTION: Activation of the phosphatidylinositol-3-kinase (PI3K) and/or mitogen-activated protein kinase (MAPK) pathways results in anti-estrogen resistance in vitro, but a biomarker with clinical validity to predict intrinsic resistance has not been identified. In metastatic breast cancer patients with previous exposure to endocrine therapy, the addition of a mammalian target of rapamycine (mTOR) inhibitor has been shown to be beneficial. Whether or not patients on adjuvant endocrine treatment might benefit from these drugs is currently unclear. A biomarker that predicts intrinsic resistance could potentially be used as companion diagnostic in this setting. We tested the clinical validity of different downstream-activated proteins in the PI3K and/or MAPK pathways to predict intrinsic tamoxifen resistance in postmenopausal primary breast cancer patients. METHODS: We recollected primary tumor tissue from patients who participated in a randomized trial of adjuvant tamoxifen (1-3 years) versus observation. After constructing a tissue micro-array, cores from 563 estrogen receptor alpha positive were immunostained for p-AKT(Thr308), p-AKT(Ser473), p-mTOR, p-p706SK and p-ERK1/2. Cox proportional hazard models for recurrence free interval were used to assess hazard ratios and interactions between these markers and tamoxifen treatment efficacy. RESULTS: Interactions were identified between tamoxifen and p-AKT(Thr308), p-mTOR, p-p70S6K and p-ERK1/2. Applying a conservative level of significance, p-p70S6K remained significantly associated with tamoxifen resistance. Patients with p-p70S6K negative tumors derived significant benefit from tamoxifen (HR 0.24, P < 0.0001), while patients whose tumor did express p-p70S6K did not (HR = 1.02, P =0.95), P for interaction 0.004. In systemically untreated breast cancer patients, p-p70S6K was associated with a decreased risk for recurrence. CONCLUSIONS: Patients whose tumor expresses p-p70S6K, as a marker of downstream PI3K and/or MAPK pathway activation, have a favorable prognosis, but do not benefit from adjuvant tamoxifen. A potential benefit from inhibitors of the PI3K/Akt/mTOR pathway in these patients needs to be further explored

PIK3CA mutations, phosphatase and tensin homolog, human epidermal growth factor receptor 2, and insulin-like growth factor 1 receptor and adjuvant tamoxifen resistance in postmenopausal breast cancer patients

Contains fulltext : 136461.pdf (publisher's version ) (Open Access)INTRODUCTION: Inhibitors of the phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway can overcome endocrine resistance in estrogen receptor (ER) alpha-positive breast cancer, but companion diagnostics indicating PI3K/AKT/mTOR activation and consequently endocrine resistance are lacking. PIK3CA mutations frequently occur in ERalpha-positive breast cancer and result in PI3K/AKT/mTOR activation in vitro. Nevertheless, the prognostic and treatment-predictive value of these mutations in ERalpha-positive breast cancer is contradictive. We tested the clinical validity of PIK3CA mutations and other canonic pathway drivers to predict intrinsic resistance to adjuvant tamoxifen. In addition, we tested the association between these drivers and downstream activated proteins. METHODS: Primary tumors from 563 ERalpha-positive postmenopausal patients, randomized between adjuvant tamoxifen (1 to 3 years) versus observation were recollected. PIK3CA hotspot mutations in exon 9 and exon 20 were assessed with Sequenom Mass Spectometry. Immunohistochemistry was performed for human epidermal growth factor receptor 2 (HER2), phosphatase and tensin homolog (PTEN), and insulin-like growth factor 1 receptor (IGF-1R). We tested the association between these molecular alterations and downstream activated proteins (like phospho-protein kinase B (p-AKT), phospho-mammalian target of rapamycin (p-mTOR), p-ERK1/2, and p-p70S6K). Recurrence-free interval improvement with tamoxifen versus control was assessed according to the presence or absence of canonic pathway drivers, by using Cox proportional hazard models, including a test for interaction. RESULTS: PIK3CA mutations (both exon 9 and exon 20) were associated with low tumor grade. An enrichment of PIK3CA exon 20 mutations was observed in progesterone receptor- positive tumors. PIK3CA exon 20 mutations were not associated with downstream-activated proteins. No significant interaction between PIK3CA mutations or any of the other canonic pathway drivers and tamoxifen-treatment benefit was found. CONCLUSION: PIK3CA mutations do not have clinical validity to predict intrinsic resistance to adjuvant tamoxifen and may therefore be unsuitable as companion diagnostic for PI3K/AKT/mTOR inhibitors in ERalpha- positive, postmenopausal, early breast cancer patients

Expression of c-FLIP is primarily detected in diffuse large B-cell lymphoma and Hodgkin's lymphoma and correlates with lack of caspase 8 activation.

Contains fulltext : 51775.pdf (publisher's version ) (Closed access)AIMS: Inhibition of apoptosis is important in the pathogenesis of lymphomas. c-FLIP, a regulator of caspase 8-mediated apoptosis, plays an important role in protecting normal B and T cells from apoptosis and possibly also in lymphomas. Because of contradictory reports about immunohistochemical detection of c-FLIP expression, the aim was to test the specificity of four antibodies in c-FLIP-transfected cells and subsequently to investigate expression of c-FLIP in different types of lymphoma. METHODS AND RESULTS: Two of four antibodies were specific. In primary lymphomas c-FLIP expression was restricted to Hodgkin's lymphomas (> 90%) and diffuse large B-cell lymphomas (44%). Burkitt lymphomas and indolent B-cell lymphomas were negative in all cases. No expression was detected in primary T-cell lymphomas, although expression was observed in one relapsed ALK+ anaplastic large cell lymphoma. Expression of c-FLIP was inversely correlated with caspase 8 activation. CONCLUSIONS: c-FLIP is important in escape of B cells from apoptosis during normal follicle centre cell reaction and may thus be an important early event in the development of B-cell-derived lymphomas. Moreover, non-specific staining of frequently used antibodies might explain discrepancies in different reports of c-FLIP expression

Irritable bowel syndrome: an integrated explanatory model for clinical practice

Background Although irritable bowel syndrome (IBS) is a symptom-based diagnosis, clinicians' management of and communication about the disorder is often hampered by an unclear conceptual understanding of the nature of the problem. We aimed to elucidate an integrated explanatory model (EM) for IBS from the existing literature for pragmatic use in the clinical setting. Methods Systematic and exploratory literature searches were performed in PubMed to identify publications on IBS and EMs. Key Results The searches did not identify a single, integrated EM for IBS. However, three main hypotheses were elucidated that could provide components with which to develop an IBS EM: (i) altered peripheral regulation of gut function (including sensory and secretory mechanisms); (ii) altered brain–gut signaling (including visceral hypersensitivity); and (iii) psychological distress. Genetic polymorphisms and epigenetic changes may, to some degree, underlie the etiology and pathophysiology of IBS and could increase the susceptibility to developing the disorder. The three model components also fit into one integrated explanation for abdominal symptoms and changes in stool habit. Additionally, IBS may share a common pathophysiological mechanism with other associated functional syndromes. Conclusions & Inferences It was possible to elucidate an integrated, three-component EM as a basis for clinicians to conceptualize the nature of IBS, with the potential to contribute to better diagnosis and management, and dialog with sufferers

Expression of the apoptosis inhibitor protease inhibitor 9 predicts clinical outcome in vaccinated patients with stage III and IV melanoma.

PURPOSE: There have been reports of successful treatment of metastatic melanoma patients with active specific immunotherapy (ASI) using irradiated autologous tumor cell vaccination. It is still unknown why some patients respond and others do not. Tumor cells can evade the immune system, for example through interference with antigen presentation by down-regulation of MHC molecules or expressing proteins interfering with cytotoxic lymphocyte-induced apoptosis like the granzyme B antagonist protease inhibitor 9 (PI-9). EXPERIMENTAL DESIGN: PI-9 expression was detected in melanoma cell lines. To investigated if PI-9 is important in the response to ASI, paraffin-embedded tissues from stage III or IV melanoma patients were stained. RESULTS: PI-9 is expressed in melanoma cells and expression in metastasized melanoma cells is, in this group of patients, an adverse prognostic marker with regard to overall and disease-free survival. Moreover, loss of MHC-1 expression frequently occurs during tumor progression but is not associated with poor clinical outcome. Interestingly, melanoma patients with a favorable clinical outcome after ASI therapy usually have high percentages of activated (granzyme B-positive) tumor-infiltrating lymphocytes at time of first diagnosis and low percentages of activated lymphocytes at time of recurrent tumor. CONCLUSIONS: Expression of PI-9 in metastatic melanoma cells is associated with unfavorable clinical outcome whereas MHC-1 down-regulation is not. Although it cannot be proven that PI-9 expression is directly responsible for failure of immunotherapy, these data suggest that expression of PI-9 could be an important immune escape mechanism and that modulation of this inhibitor may enhance the efficacy of immunotherapy

Immunohistochemical profiling of caspase signaling pathways predicts clinical response to chemotherapy in primary nodal diffuse large B-cell lymphomas.

Contains fulltext : 47593.pdf (publisher's version ) (Closed access)We used biopsy specimens of primary nodal diffuse large B-cell lymphoma (DLBCL) to investigate whether the inhibition of caspase 8 and/or 9 apoptosis signaling pathways predicts clinical outcome. Expression levels of cellular FLICE inhibitory protein (c-Flip) and numbers of active caspase 3-positive lymphoma cells were used to determine the status of the caspase 8-mediated pathway. Expression levels of Bcl-2 and X-linked inhibitor of apoptosis (XIAP) were used to determine the status of the caspase 9-mediated pathway. Expression of c-Flip, XIAP, Bcl-2, and caspase 3 activity all provided prognostic information. According to these immunohistochemical parameters, inhibition of either or both caspase signaling pathways was detected in all patients. Three groups of patients were identified, one with a caspase 8 inhibition profile, one with caspase 8 and 9 inhibition profiles, and one with a caspase 9 inhibition profile. Caspase 9 inhibition was strongly associated with poor response to chemotherapy and usually with fatal outcome, whereas caspase 8 inhibition was associated with excellent clinical outcome. Thus, our data strongly suggest that inhibition of the caspase 9-mediated pathway, but not the caspase 8-mediated pathway, is a major cause for therapy resistance in patients with nodal DLBCL

Profiling of apoptosis genes allows for clinical stratification of primary nodal diffuse large B-cell lymphomas.

Contains fulltext : 36362.pdf (publisher's version ) (Closed access)Intrinsic resistance of lymphoma cells to apoptosis is a probable mechanism causing chemotherapy resistance and eventual fatal outcome in patients with diffuse large B cell lymphomas (DLBCL). We investigated whether microarray expression profiling of apoptosis related genes predicts clinical outcome in 46 patients with primary nodal DLBCL. Unsupervised cluster analysis using genes involved in apoptosis (n = 246) resulted in three separate DLBCL groups partly overlapping with germinal centre B-lymphocytes versus activated B-cells like phenotype. One group with poor clinical outcome was characterised by high expression levels of pro-and anti-apoptotic genes involved in the intrinsic apoptosis pathway. A second group, also with poor clinical outcome, was characterised by high levels of apoptosis inducing cytotoxic effector genes, possibly reflecting a cellular cytotoxic immune response. The third group showing a favourable outcome was characterised by low expression levels of genes characteristic for both other groups. Our results suggest that chemotherapy refractory DLBCL are characterised either by an intense cellular cytotoxic immune response or by constitutive activation of the intrinsic mediated apoptosis pathway with concomitant downstream inhibition of this apoptosis pathway. Consequently, strategies neutralising the function of apoptosis-inhibiting proteins might be effective as alternative treatment modality in part of chemotherapy refractory DLBCL