The unfolded protein response (UPR) is an evolutionarily conserved mechanism that activates both proapoptotic and survival pathways to allow eukaryotic cells to adapt to endoplasmic reticulum (ER) ...stress. Although the UPR has been implicated in tumorigenesis, its precise role in endogenous cancer remains unclear. A major UPR protective response is the induction of the ER chaperone GRP78/BiP, which is expressed at high levels in a variety of tumors and confers drug resistance in both proliferating and dormant cancer cells. To determine the physiologic role of GRP78 in in situ-generated tumor and the consequence of its suppression on normal organs, we used a genetic model of breast cancer in the Grp78 heterozygous mice where GRP78 expression level was reduced by about half, mimicking anti-GRP78 agents that achieve partial suppression of GRP78 expression. Here, we report that Grp78 heterozygosity has no effect on organ development or antibody production but prolongs the latency period and significantly impedes tumor growth. Our results reveal three major mechanisms mediated by GRP78 for cancer progression: enhancement of tumor cell proliferation, protection against apoptosis, and promotion of tumor angiogenesis. Importantly, although partial reduction of GRP78 in the Grp78 heterozygous mice substantially reduces the tumor microvessel density, it has no effect on vasculature of normal organs. Our findings establish that a key UPR target GRP78 is preferably required for pathophysiologic conditions, such as tumor proliferation, survival, and angiogenesis, underscoring its potential value as a novel therapeutic target for dual antitumor and antiangiogenesis activity.
The discovery of predictive factors for chemoresistance is critical for improving adjuvant therapy for cancer patients. The 78-kDa glucose-regulated protein (GRP78), widely used as an indicator of ...the unfolded protein response (UPR), is induced in the tumor microenvironment. In vitro studies suggest that GRP78 confers chemoresistance to topoisomerase inhibitors, such as Adriamycin (doxorubicin). Here, we report on a retrospective cohort study of 127 stage II and III breast cancer patients who were treated with Adriamycin-based chemotherapy. Archival tumor specimens were available for analysis and the relationship of GRP78 expression level to "time to recurrence" (TTR), used as a surrogate marker for drug resistance, was examined. Our data show that 67% of the study subjects expressed high level of GRP78 in their tumors before the initiation of chemotherapy and suggest an association between GRP78 positivity and shorter TTR hazard ratio (HR), 1.78; P = 0.16. Interestingly, subgroup analysis reveals that the HR for the GRP78-positive group increased significantly among patients who did not receive further taxane treatment (HR, 3.00; P = 0.022) and among mastectomy patients (HR, 3.33; P = 0.027). The HR was even stronger among mastectomy patients who did not receive further taxane treatment (HR, 4.82; P = 0.010). The use of GRP78 as a predictor for chemoresponsiveness and the potential interaction of GRP78 and/or the UPR pathways with taxanes warrant larger studies.
Summary
Background:
Until the advent of T cell check point inhibitors standard second-line therapy for patients with metastatic urothelial cancer (mUC) was undefined. Histone deacetylase inhibitors ...(HDACi) have anti-cancer activity in a variety of tumor models including modulation of apoptosis in bladder cancer cell lines. We evaluated the efficacy and toxicity of the HDACi vorinostat in patients with mUC failing first-line platinum-based therapy either in the adjuvant/neoadjuvant setting or for recurrent/advanced disease.
Methods:
Vorinostat was given orally 200 mg twice daily continuously until progression or unacceptable toxicity. The primary end point was RECIST response rate (RR); a RR > 20% was deemed interesting in a 2-stage design requiring one response in the first 12 patients to proceed to 2nd stage for a total of 37 subjects. CT or MRI scan imaging occurred every 6 weeks.
Results:
Fourteen patients were accrued characterized by: median age 66 years (43–84); Caucasian (79%); males (86%); and Karnofsky performance status ≥90 (50%). Accrual was terminated in the first stage as no responses were observed. Best response was stable disease (3 patients). Progression was observed in 8 patients. Two patients came off therapy prior to re-imaging and a 3rd patient died while on treatment and was not assessed for response. Median number of cycles was 2 (range 1–11). Median disease-free survival and overall survival times were 1.1 (0.8, 2.1) & 3.2 (2.1, 14.5) months, respectively. Toxicities were predominantly cytopenias and thrombocytopenic bleeding. Two pts. had grade 5 toxicity unlikely related to treatment. Two pts. had grade 4 and 6 had grade 3 toxicities observed. Two patients with stable disease remained on therapy for 6+ cycles.
Conclusions:
Vorinostat on this dose-schedule had limited efficacy and significant toxicity resulting in a unfavorable risk:benefit ratio in patients with mUC. NCT00363883.
The National Cancer Institute (NCI) Investigational Drug Steering Committee (IDSC) charged the Biomarker Task Force to develop recommendations to improve the decisions about incorporation of ...biomarker studies in early investigational drug trials. The Task Force members reviewed biomarker trials, the peer-reviewed literature, NCI and U.S. Food and Drug Administration (FDA) guidance documents, and conducted a survey of investigators to determine practices and challenges to executing biomarker studies in clinical trials of new drugs in early development. This document provides standard definitions and categories of biomarkers, and lists recommendations to sponsors and investigators for biomarker incorporation into such trials. Our recommendations for sponsors focus on the identification and prioritization of biomarkers and assays, the coordination of activities for the development and use of assays, and for operational activities. We also provide recommendations for investigators developing clinical trials with biomarker studies for scientific rationale, assay criteria, trial design, and analysis. The incorporation of biomarker studies into early drug trials is complex. Thus the decision to proceed with studies of biomarkers should be based on balancing the strength of science, assay robustness, feasibility, and resources with the burden of proper sample collection on the patient and potential impact of the results on drug development. The Task Force provides these guidelines in the hopes that improvements in biomarker studies will enhance the efficiency of investigational drug development.
Nineteen patients with high-risk resected stage III and IV melanoma were immunized with three tumor antigen epitope peptides from gp100, MART-1, and tyrosinase emulsified with adjuvant Montanide ISA ...51 and received a fully human anti-cytotoxic T-lymphocyte antigen-4 (anti-CTLA-4) monoclonal antibody MDX-010. Each of three cohorts received escalating doses of antibody with vaccine primarily to evaluate the toxicities and maximum-tolerated dose (MTD) of MDX-010 with vaccine. MDX-010 pharmacokinetics and immune responses were secondary end points.
Peptide immunizations with MDX-010 were administered every 4 weeks for 6 months and then every 12 weeks for 6 months. A leukapheresis to obtain peripheral-blood mononuclear cells for immune analyses was performed before treatment and after the sixth vaccination. Patients were observed until relapse.
Grade 3 gastrointestinal (GI) toxicity (diarrhea or abdominal pain) was observed in three patients in the highest dose cohort and one in the middle dose cohort who seemed to be autoimmune. That defined the MTD with vaccine on this schedule at 1 mg/kg. Of eight patients with evidence of autoimmunity, three have experienced disease relapse. Of 11 patients without autoimmune symptoms, nine have experienced disease relapse. Significant immune responses were measured by tetramer and enzyme-linked immunospot assays against gp100 and MART-1.
Dose-related autoimmune adverse events, predominantly skin and GI toxicities, were reversible. Patients mounted an antigen-specific immune response to a peptide vaccine when combined with a human anti-CTLA-4 antibody.
To characterize long-term repopulation of peripheral immune cells following alemtuzumab-induced lymphopenia in relapsing-remitting MS (RRMS), with a focus on regulatory cell types, and to explore ...associations with clinical outcome measures.
The project was designed as a multicenter add-on longitudinal mechanistic study for RRMS patients enrolled in CARE-MS II, CARE-MS II extension at the University of Southern California and Stanford University, and an investigator-initiated study conducted at the Universities of British Columbia and Chicago. Methods involved collection of blood at baseline, prior to alemtuzumab administration, and at months 5, 11, 17, 23, 36, and 48 post-treatment. T cell, B cell, and natural killer (NK) cell subsets, chemokine receptor expression in T cells, in vitro cytokine secretion patterns, and regulatory T cell (Treg) function were assessed. Clinical outcomes, including expanded disability status score (EDSS), relapses, conventional magnetic resonance imaging (MRI) measures, and incidents of secondary autoimmunity were tracked.
Variable shifts in lymphocyte populations occurred over time in favor of CD4+ T cells, B cells, and NK cells with surface phenotypes characteristic of regulatory subsets, accompanied by reduced ratios of effector to regulatory cell types. Evidence of increased Treg competence was observed after each treatment course. CD4+ and CD8+ T cells that express CXCR3 and CCR5 and CD8+ T cells that express CDR3 and CCR4 were also enriched after treatment, indicating heightened trafficking potential in activated T cells. Patterns of repopulation were not associated with measures of clinical efficacy or secondary autoimmunity, but exploratory analyses using a random generalized estimating equation (GEE) Poisson model provide preliminary evidence of associations between pro-inflammatory cell types and increased risk for gadolinium (Gd+) enhancing lesions, while regulatory subsets were associated with reduced risk. In addition, the risk for T2 lesions correlated with increases in CD3+CD8+CXCR3+ cells.
Lymphocyte repopulation after alemtuzumab treatment favors regulatory subsets in the T cell, B cell, and NK cell compartments. Clinical efficacy may reflect the sum of interactions among them, leading to control of potentially pathogenic effector cell types. Several immune measures were identified as possible biomarkers of lesion activity. Future studies are necessary to more precisely define regulatory and effector subsets and their contributions to clinical efficacy and risk for secondary autoimmunity in alemtuzumab-treated patients, and to reveal new insights into mechanisms of immunopathogenesis in MS.
Parent trials for this study are registered with ClinicalTrials.gov: CARE-MS II: NCT00548405, CARE-MS II extension: NCT00930553 and ISS: NCT01307332.
To examine interactions among clinical factors and pathologic biomarkers in predicting the outcome of patients with diffuse large B-cell lymphoma (DLBCL) treated with rituximab-based ...immunochemotherapy.
In 85 patients treated at a single institution, clinicopathologic variables were analyzed, including the International Prognostic Index (IPI); germinal/nongerminal center phenotype; MYC, p53, BCL2, Ki-67, and Epstein-Barr virus (EBV) expression; and MYC translocation status.
In univariate analysis, overall survival (OS) was worse for patients with high IPI scores, nongerminal center phenotype, high MYC and p53 expression by immunohistochemistry, and EBV positivity. In multivariable analysis, p53 expression was the strongest prognostic factor (P < .05) independent of IPI and cell of origin. A significant positive association between p53 and MYC expression was found. Moreover, coexpression of p53/MYC had an enhanced negative effect on OS independent of BCL2 expression.
Immunohistochemical assessment of p53, particularly in combination with MYC, could be useful in identifying a high-risk subgroup of DLBCL.
Recent high-throughput studies revealed recurrent RUNX1 mutations in breast cancer, specifically in oestrogen receptor-positive (ER(+)) tumours. However, mechanisms underlying the implied ...RUNX1-mediated tumour suppression remain elusive. Here, by depleting mammary epithelial cells of RUNX1 in vivo and in vitro, we demonstrate combinatorial regulation of AXIN1 by RUNX1 and oestrogen. RUNX1 and ER occupy adjacent elements in AXIN1's second intron, and RUNX1 antagonizes oestrogen-mediated AXIN1 suppression. Accordingly, RNA-seq and immunohistochemical analyses demonstrate an ER-dependent correlation between RUNX1 and AXIN1 in tumour biopsies. RUNX1 loss in ER(+) mammary epithelial cells increases β-catenin, deregulates mitosis and stimulates cell proliferation and expression of stem cell markers. However, it does not stimulate LEF/TCF, c-Myc or CCND1, and it does not accelerate G1/S cell cycle phase transition. Finally, RUNX1 loss-mediated deregulation of β-catenin and mitosis is ameliorated by AXIN1 stabilization in vitro, highlighting AXIN1 as a potential target for the management of ER(+) breast cancer.
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