GliPR1 knockdown by RNA interference exerts anti-glioma effects in vitro and in vivo.

INTRODUCTION: In human glioblastomas, glioma pathogenesis-related protein1 (GliPR1) is overexpressed and appears to be an oncoprotein. We investigated whether GliPR1 knockdown in glioma cells by RNA interference exerts anti-glioma effects. METHODS: Experiments used human glioblastoma cell lines transduced with GliPR1 shRNA (sh#301, sh#258). Transduction produced stringent doxycycline-dependent GliPR1 knockdown in clones (via lentiviral "all-in-one" TetOn-shRNA vector) or stable GliPR1 knockdown in polyclonal cells (via constitutive retroviral-shRNA vector). In vitro assessments included cellular proliferation and clonogenic survival. In vivo assessments in tumor-bearing nude mice included tumor growth and survival. RESULTS: Using doxycycline-dependent GliPR1 knockdown, shGliPR1-transduced U87-MG clones demonstrated reductions in cellular proliferation in the presence versus absence of doxycycline. Using stable GliPR1 knockdown, polyclonal shGliPR1-transduced U87-MG, A172, and U343-MG cells consistently showed decreased clonogenic survival and induced apoptosis (higher proportion of early apoptotic cells) compared to control shLuc-transduced cells. In tumor-bearing nude mice, using doxycycline-dependent GliPR1 knockdown, subcutaneous and cranial transplantation of the U87-MG clone 980-5 (transduced with GliPR1 sh#301) resulted in reduced subcutaneous tumor volume and cerebral tumor area in doxycycline-treated mice versus those left untreated. Using stable GliPR1 knockdown, nude mice cranially transplanted with polyclonal U87-MG cells transduced with GliPR1 sh#258 had significantly prolonged survival compared to mice cranially transplanted with control shLuc-transduced cells (41 versus 26 days; P < 0.001). CONCLUSION: GliPR1 knockdown in glioma cells decreased cellular proliferation, decreased clonogenic survival, and induced apoptosis in vitro, and reduced glioblastoma tumor growth and prolonged survival in vivo. These findings support that GliPR1 may have potential value as a therapeutic target.

Comparison of central and local serial CT assessments of metastatic renal cell carcinoma patients in a clinical phase IIB study.

Background Clinical oncological studies attempt to improve precision of data by central radiological assessments. However, it is unclear, to which extent local and central assessments diverge. Purpose To quantify inter-reader variability and the deviation of local from central radiological assessments of computed tomography (CT) scans. Material and Methods This was a sub-study of a randomized clinical phase IIb trial in metastatic renal cell carcinoma (RCC), comparing first-line sorafenib with interferon-alpha-2a (IFN-α-2a). It analyzed agreements of local with central RECIST CT assessments by Cohen's kappa (κ), symmetry tests, deviations in waterfall plots, Bland-Altman plots, and parametric survival analyses. Results The concordance between local and central radiologic review was quantified by κ = 0.53. While local assessment yielded progressive disease (PD) in 18.6%, central assessment classified 22.5% of patient time points as PD exhibiting only a partial overlap with the 18.6% The tumor shrinkage rates in waterfall plots were 68.1% in local and 55.8% in central review (57.8% and 59% by Reader 1 and Reader 2). Bland-Altman plots identified a systematic shift of tumor change rates by -7.5% in local compared to central assessments, that may reflect a systematic tendency of more favorable results in local assessments. The discordance between local and central review was reflected by a time to progression (TTP) hazard ratio (HR) of 1.73 ( P = 0.0003). Conclusion These data suggest that central radiologic review may reduce technical measurement variability in clinical trials, which should be scrutinized in future studies compared to a volumetric reference.

NEPTUNE: Phase 3 Study of First-Line Durvalumab Plus Tremelimumab in Patients With Metastatic NSCLC.

INTRODUCTION: NEPTUNE, a phase 3, open-label study, evaluated first-line durvalumab plus tremelimumab versus chemotherapy in metastatic NSCLC (mNSCLC). METHODS: Eligible patients with EGFR and ALK wild-type mNSCLC were randomized (1:1) to first-line durvalumab (20 mg/kg every 4 weeks until progression) plus tremelimumab (1 mg/kg every 4 weeks for up to four doses) or standard chemotherapy. Randomization was stratified by tumor programmed death-ligand 1 expression (≥25% versus <25%), tumor histologic type, and smoking history. The amended primary end point was overall survival (OS) in patients with blood tumor mutational burden (bTMB) greater than or equal to 20 mutations per megabase (mut/Mb). Secondary end points included progression-free survival (PFS) in patients with bTMB greater than or equal to 20 mut/Mb and safety and tolerability in all treated patients. RESULTS: As of June 24, 2019, 823 patients were randomized (intention-to-treat [ITT]); 512 (62%) were bTMB-evaluable, with 129 of 512 (25%) having bTMB greater than or equal to 20 mut/Mb (durvalumab plus tremelimumab [n = 69]; chemotherapy [n = 60]). Baseline characteristics were balanced in the intention-to-treat. Among patients with bTMB greater than or equal to 20 mut/Mb, OS improvement with durvalumab plus tremelimumab versus chemotherapy did not reach statistical significance (hazard ratio 0.71 [95% confidence interval: 0.49-1.05; p = 0.081]; median OS, 11.7 versus 9.1 months); the hazard ratio for PFS was 0.77 (95% confidence interval, 0.51-1.15; median PFS, 4.2 versus 5.1 months). In the overall safety population, incidence of grade 3 or 4 treatment-related adverse events was 20.7% (durvalumab plus tremelimumab) and 33.6% (chemotherapy). CONCLUSIONS: NEPTUNE did not meet its primary end point of improved OS with durvalumab plus tremelimumab versus chemotherapy in patients with mNSCLC and bTMB greater than or equal to 20 mut/Mb. Despite the amended study design, with a resultant small primary analysis population, therapeutic activity was aligned with expectations based on mechanistic biology and previous studies.

HIV-1 infection suppresses expression of host cell cycle-associated gene PDS5A.

OBJECTIVE: To unravel the interplay between HIV-1 and its host cell, the effect of HIV-1 infection on cellular gene expression was investigated. METHODS: HIV-1(SF33)-infected and uninfected H9 T cells were screened by differential display and RNase protection assay. The finding (PDS5A) was confirmed in HIV-1(Lai)-infected P4-CCR5 HeLa cells, which were also examined after PDS5A siRNA knockdown in regard to HIV-1 replication by quantitative RT-PCR, p24 ELISA and LTR-driven ß-galactosidase expression. The PDS5A knockdown effect on cellular gene expressions was studied by microarray analysis. PDS5A tissue expression was determined by Northern blotting. RESULTS: Regulator of cohesion maintenance, homolog A (PDS5A) was found to be down-regulated by HIV-1. When PDS5A was suppressed by siRNA, HIV-1 replication was unaffected. PDS5A was found to be highly expressed in skeletal muscle tissue, and to lesser degrees in pancreas, heart, placenta, lung, kidney, liver and brain. Microarray analysis of PDS5A knockdown revealed 91 differential gene products over-representing cell cycle, transport and protein stability regulation, including 4 genes (PP2A, RANTES, PCAF, TCF7L2) previously reported to interact with HIV-1. CONCLUSION: The data show a downregulation of proliferation-associated host gene PDS5A and suggest a role of PDS5A in HIV-1-induced cellular pathogenesis but not viral replication.

A Blood-based Assay for Assessment of Tumor Mutational Burden in First-line Metastatic NSCLC Treatment: Results from the MYSTIC Study.

PURPOSE: Tumor mutational burden (TMB) has been shown to be predictive of survival benefit in patients with non-small cell lung cancer (NSCLC) treated with immune checkpoint inhibitors. Measuring TMB in the blood (bTMB) using circulating cell-free tumor DNA (ctDNA) offers practical advantages compared with TMB measurement in tissue (tTMB); however, there is a need for validated assays and identification of optimal cutoffs. We describe the analytic validation of a new bTMB algorithm and its clinical utility using data from the phase III MYSTIC trial. PATIENTS AND METHODS: The dataset used for the clinical validation was from MYSTIC, which evaluated first-line durvalumab (anti-PD-L1 antibody) ± tremelimumab (anticytotoxic T-lymphocyte-associated antigen-4 antibody) or chemotherapy for metastatic NSCLC. bTMB and tTMB were evaluated using the GuardantOMNI and FoundationOne CDx assays, respectively. A Cox proportional hazards model and minimal P value cross-validation approach were used to identify the optimal bTMB cutoff. RESULTS: In MYSTIC, somatic mutations could be detected in ctDNA extracted from plasma samples in a majority of patients, allowing subsequent calculation of bTMB. The success rate for obtaining valid TMB scores was higher for bTMB (809/1,001; 81%) than for tTMB (460/735; 63%). Minimal P value cross-validation analysis confirmed the selection of bTMB ≥20 mutations per megabase (mut/Mb) as the optimal cutoff for clinical benefit with durvalumab + tremelimumab. CONCLUSIONS: Our study demonstrates the feasibility, accuracy, and reproducibility of the GuardantOMNI ctDNA platform for quantifying bTMB from plasma samples. Using the new bTMB algorithm and an optimal bTMB cutoff of ≥20 mut/Mb, high bTMB was predictive of clinical benefit with durvalumab + tremelimumab versus chemotherapy.

Patient-Reported Outcomes with Durvalumab With or Without Tremelimumab Versus Standard Chemotherapy as First-Line Treatment of Metastatic Non-Small-Cell Lung Cancer (MYSTIC).

BACKGROUND: The phase 3 MYSTIC study of durvalumab ± tremelimumab versus chemotherapy in metastatic non-small-cell lung cancer (NSCLC) patients with tumor cell (TC) programmed cell death ligand 1 (PD-L1) expression ≥ 25% did not meet its primary endpoints. We report patient-reported outcomes (PROs). PATIENTS AND METHODS: Treatment-naïve patients were randomized (1:1:1) to durvalumab, durvalumab + tremelimumab, or chemotherapy. PROs were assessed in patients with PD-L1 TC ≥ 25% using EORTC Quality of Life Questionnaire (QLQ)-C30/LC13. Changes from baseline (12 months) for prespecified PRO endpoints of interest were analyzed by mixed model for repeated measures (MMRM) and time to deterioration (TTD) by stratified log-rank tests. RESULTS: There were no between-arm differences in baseline PROs (N = 488). Between-arm differences in MMRM-adjusted mean changes from baseline favored at least one of the durvalumab-containing arms versus chemotherapy (nominal P < .01) for C30 fatigue: durvalumab (-9.5; 99% confidence interval [CI], -17.0 to -2.0), durvalumab + tremelimumab (-11.7; 99% CI, -19.4 to -4.1); and for C30 appetite loss: durvalumab (-11.9; 99% CI, -21.1 to -2.7). TTD was longer with at least one of the durvalumab-containing arms versus chemotherapy (nominal P < .01) for global health status/quality of life: durvalumab (hazard ratio [HR] = 0.7; 95% CI, 0.5-1.0), durvalumab + tremelimumab (HR = 0.7; 95% CI, 0.5-1.0); and for physical functioning: durvalumab (HR = 0.6; 95% CI, 0.4-0.8), durvalumab + tremelimumab (HR = 0.6; 95% CI, 0.5-0.9) (both C30); as well as for the key symptoms of dyspnea: durvalumab (HR = 0.6; 95% CI, 0.5-0.9), durvalumab + tremelimumab (HR = 0.7; 95% CI, 0.5-1.0) (both LC13); fatigue: durvalumab + tremelimumab (HR = 0.6; 95% CI, 0.4-0.8); and appetite loss: durvalumab (HR = 0.5; 95% CI, 0.4-0.7), durvalumab + tremelimumab (HR = 0.7; 95% CI, 0.5-0.9) (both C30). CONCLUSION: Durvalumab ± tremelimumab versus chemotherapy reduced symptom burden and improved TTD of PROs, suggesting it had no detrimental effects on quality of life in metastatic NSCLC patients.

Inhibition of HIV-1 replication by small interfering RNAs directed against glioma pathogenesis related protein (GliPR) expression.

BACKGROUND: Previously, we showed that glioma pathogenesis related protein (GliPR) is induced in CEM T cells upon HIV-1 infection in vitro. To examine whether GliPR plays a role as HIV dependency factor (HDF), we tested the effect of GliPR suppression by siRNA on HIV-1 replication. RESULTS: Induction of GliPR expression by HIV-1 was confirmed in P4-CCR5 cells. When GliPR was suppressed by siRNA, HIV-1 replication was significantly reduced as measured by HIV-1 transcript levels, HIV-1 p24 protein levels, and HIV-1 LTR-driven reporter gene expression, suggesting that GliPR is a cellular co-factor of HIV-1. Microarray analysis of uninfected HeLa cells following knockdown of GliPR revealed, among a multitude of gene expression alterations, a down-regulation of syndecan-1, syndecan-2, protein kinase C alpha (PRKCA), the catalytic subunit beta of cAMP-dependent protein kinase (PRKACB), nuclear receptor co-activator 3 (NCOA3), and cell surface protein CD59 (protectin), all genes having relevance for HIV-1 pathology. CONCLUSIONS: The up-regulation of GliPR by HIV-1 and the early significant inhibition of HIV-1 replication mediated by knockdown of GliPR reveal GliPR as an important HIV-1 dependency factor (HDF), which may be exploited for HIV-1 inhibition.

Durvalumab With or Without Tremelimumab vs Standard Chemotherapy in First-line Treatment of Metastatic Non-Small Cell Lung Cancer: The MYSTIC Phase 3 Randomized Clinical Trial.

Importance: Checkpoint inhibitors targeting programmed cell death 1 or its ligand (PD-L1) as monotherapies or in combination with anti-cytotoxic T-lymphocyte-associated antigen 4 have shown clinical activity in patients with metastatic non-small cell lung cancer. Objective: To compare durvalumab, with or without tremelimumab, with chemotherapy as a first-line treatment for patients with metastatic non-small cell lung cancer. Design, Setting, and Participants: This open-label, phase 3 randomized clinical trial (MYSTIC) was conducted at 203 cancer treatment centers in 17 countries. Patients with treatment-naive, metastatic non-small cell lung cancer who had no sensitizing EGFR or ALK genetic alterations were randomized to receive treatment with durvalumab, durvalumab plus tremelimumab, or chemotherapy. Data were collected from July 21, 2015, to October 30, 2018. Interventions: Patients were randomized (1:1:1) to receive treatment with durvalumab (20 mg/kg every 4 weeks), durvalumab (20 mg/kg every 4 weeks) plus tremelimumab (1 mg/kg every 4 weeks, up to 4 doses), or platinum-based doublet chemotherapy. Main Outcomes and Measures: The primary end points, assessed in patients with ≥25% of tumor cells expressing PD-L1, were overall survival (OS) for durvalumab vs chemotherapy, and OS and progression-free survival (PFS) for durvalumab plus tremelimumab vs chemotherapy. Analysis of blood tumor mutational burden (bTMB) was exploratory. Results: Between July 21, 2015, and June 8, 2016, 1118 patients were randomized. Baseline demographic and disease characteristics were balanced between treatment groups. Among 488 patients with ≥25% of tumor cells expressing PD-L1, median OS was 16.3 months (95% CI, 12.2-20.8) with durvalumab vs 12.9 months (95% CI, 10.5-15.0) with chemotherapy (hazard ratio [HR], 0.76; 97.54% CI, 0.56-1.02; P = .04 [nonsignificant]). Median OS was 11.9 months (95% CI, 9.0-17.7) with durvalumab plus tremelimumab (HR vs chemotherapy, 0.85; 98.77% CI, 0.61-1.17; P = .20). Median PFS was 3.9 months (95% CI, 2.8-5.0) with durvalumab plus tremelimumab vs 5.4 months (95% CI, 4.6-5.8) with chemotherapy (HR, 1.05; 99.5% CI, 0.72-1.53; P = .71). Among 809 patients with evaluable bTMB, those with a bTMB ≥20 mutations per megabase showed improved OS for durvalumab plus tremelimumab vs chemotherapy (median OS, 21.9 months [95% CI, 11.4-32.8] vs 10.0 months [95% CI, 8.1-11.7]; HR, 0.49; 95% CI, 0.32-0.74). Treatment-related adverse events of grade 3 or higher occurred in 55 (14.9%) of 369 patients who received treatment with durvalumab, 85 (22.9%) of 371 patients who received treatment with durvalumab plus tremelimumab, and 119 (33.8%) of 352 patients who received treatment with chemotherapy. These adverse events led to death in 2 (0.5%), 6 (1.6%), and 3 (0.9%) patients, respectively. Conclusions and Relevance: The phase 3 MYSTIC study did not meet its primary end points of improved OS with durvalumab vs chemotherapy or improved OS or PFS with durvalumab plus tremelimumab vs chemotherapy in patients with ≥25% of tumor cells expressing PD-L1. Exploratory analyses identified a bTMB threshold of ≥20 mutations per megabase for optimal OS benefit with durvalumab plus tremelimumab. Trial Registration: ClinicalT rials.gov Identifier: NCT02453282.

Risk and prognosis of central nervous system leukemia in patients with Philadelphia chromosome-positive acute leukemias treated with imatinib mesylate.

PURPOSE: In patients with acute leukemias, a lymphoid phenotype, the presence of a Philadelphia chromosome (Ph), and inadequate central nervous system (CNS)-directed prophylactic therapy are risk factors for CNS involvement. Imatinib mesylate has promising single-agent antileukemic activity in patients with advanced Ph(+) acute leukemias. It was the aim of this analysis to determine the incidence of, and risk factors associated with, meningeal leukemia during imatinib monotherapy. STUDY DESIGN: We analyzed 107 consecutive patients with relapsed or refractory Ph(+) acute lymphoid leukemia (ALL; n = 65) or chronic myeloid leukemia blast crisis (n = 42) who were enrolled in successive Phase II trials of single-agent imatinib and who did not receive routine prophylactic intrathecal chemotherapy. RESULTS: CNS leukemia developed in 13 of 107 patients (12%) and was associated primarily with a lymphoid or bilineage phenotype (12 of 78; 15%) and with imatinib refractory Ph(+) ALL (5 of 19; 26%). Meningeal leukemia did not occur among patients who received prior prophylactic cranial irradiation. The median survival with combined CNS and systemic disease was 108 days (range, 58-141), with no patient surviving long term. In contrast, two of three patients with exclusively meningeal leukemia achieved prolonged molecular remissions with intrathecal chemotherapy, cranial irradiation, and continued imatinib. CONCLUSIONS: Patients with Ph(+) ALL are at considerable risk of meningeal leukemia during imatinib monotherapy and should routinely receive CNS prophylaxis. Although the prognosis with combined meningeal and systemic relapse is dismal, patients with an isolated meningeal relapse may still achieve sustained remissions. The optimal type of CNS-directed treatment and the extent of protection afforded by prophylactic cranial irradiation remain to be defined.

Comparison of volumetric and linear serial CT assessments of lung metastases in renal cell carcinoma patients in a clinical phase IIB study.

RATIONALE AND OBJECTIVES: Accuracy of radiologic assessment may have a crucial impact on clinical studies and therapeutic decisions. We compared the variability of a central radiologic assessment (RECIST) and computer-aided volume-based assessment of lung lesions in patients with metastatic renal cell carcinoma (RCC). MATERIALS AND METHODS: The investigation was prospectively planned as a substudy of a clinical randomized phase IIB therapeutic trial in patients with RCC. Starting with the manual study diameter (SDM) of the central readers using RECIST in the clinical study, we performed computer-aided volume measurements. We compared SDM to an automated RECIST diameter (aRDM) and the diameter of a volume-equivalent sphere (effective diameter [EDM]), both for the individual size measurements and for the change rate (CR) between consecutive time points. One hundred thirty diameter pairs of 30 lung lesions from 14 patients were evaluable, forming 55 change pairs over two consecutive time points each. RESULTS: The SDMs of two different readers showed a correlation of 95.6%, whereas the EDMs exhibited an excellent correlation of 99.4%. Evaluation of CRs showed an SDM-CR correlation of 63.9%, which is substantially weaker than the EDM-CR correlation of 87.6%. The variability of SDM-CR is characterized by a median absolute difference of 11.4% points versus the significantly lower 1.8% points EDM-CRs variability (aRDM: 3.2% points). The limits of agreement between readers suggest that an EDM change of 10% or 1 mm can already be significant. CONCLUSIONS: Computer-aided volume-based assessments result in markedly reduced variability of parameters describing size and change, which may offer an advantage of earlier response evaluations and treatment decisions for patients.

Risk-adapted treatment according to minimal residual disease in adult ALL.

The evaluation of minimal residual disease (MRD) is a new diagnostic method which is applicable in various malignant disorders. Acute lymphoblastic leukaemia (ALL) is a somewhat ideal disease in this respect because >90% of the patients show individual clonal markers and because several methods for MRD evaluation are already established. Futhermore, it was demonstrated that level and course of MRD are significantly correlated with relapse risk in childhood and in adult ALL. In clinical practice MRD evaluation may serve for several purposes such as follow-up of individual course of disease, identification of new prognostic factors or evaluation of single treatment elements. We discuss these options as well as general considerations for MRD-based risk stratification and treatment options for risk groups. Practical applications are analysed because prospective MRD-based clinical trials have been recently started. Finally, future options for application of MRD evaluation and also limitations and pitfalls of this method are reviewed.

Proliferative arrest and cell cycle regulation in CD8(+)CD28(-) versus CD8(+)CD28(+) T cells.

CD8(+)CD28(-) T cells have been characterized by oligoclonal expansions, impaired proliferative responses, but preserved cytotoxicity and reduced telomeres. To examine this subset further and define the underlying mechanisms of proliferation arrest, we investigated several features of this cell type compared with CD8(+)CD28(+) controls. We analyzed expression of various activation markers, thymidine incorporation upon activation, T-cell receptor (TCR) zeta-chain phosphorylation, cell cycle characteristics, and cell cycle related gene expression. Flow cytometry revealed higher expression of CD11b, CD29, CD57, and CD94, and lower expression of CD25 in CD8(+)CD28(-) compared with CD8(+)CD28(+) T cells. Sorted CD8(+)CD16(-)CD28(-) cells exhibited decreased phosphorylation of the TCR zeta-chain in three of four probands. Proliferation of these T cells was impaired, even when activated with mitogens that bypass TCR signaling. Cell cycle profiles demonstrated a lower percentage of cycling cells and significantly higher levels of cyclin dependent kinase inhibitor p16(INK4a) in the CD28(-) subset compared with the CD28(+) control. These observations suggest that expanded CD8(+)CD28(-) T cells in normal elderly individuals have reduced proliferation concomitant with increased p16(INK4a) expression. Defects in TCR signaling were associated with altered TCR zeta-chain phosphorylation.

Characterization of ZC3H15 as a potential TRAF-2-interacting protein implicated in the NFκB pathway and overexpressed in AML.

The gene product of the zinc finger CCCH-type containing 15 (ZC3H15) gene, an immediate early erythropoietin response gene (synonymous: LEREPO4), was further characterized. ZC3H15 was expressed ubiquitously in all human tissues tested by northern blotting and showed mainly a diffuse cytoplasmic distribution by immune fluorescence microscopy and western blotting of subcellular protein fractions. The expression of ZC3H15 was downregulated effectively in HeLa cells to ≤13% of the control by transfection of specific small interfering RNA (siRNA). Subsequent Affymetrix microarray analysis revealed 202 differentially expressed genes including 114 induced (≥3-fold) genes and 88 suppressed (≤0.3-fold) genes. The gene ontology (GO) categories containing an over-representation of differentially expressed genes comprised cell growth, transcription, cell adhesion, regulation of NF-κB, regulation of MAPK, cell cycle arrest and immune response. ZC3H15 interacted with the signaling adapter protein tumor necrosis factor receptor associated factor 2 (TRAF-2) as shown by co-immunoprecipitation. ZC3H15 expression was found to be significantly increased in acute myeloid leukemia (AML) samples compared to MDS, CML, ALL and normal bone marrow samples using the Leukemia Gene Atlas (LGA) database. Based on these data, it is hypothesized that ZC3H15 may interact with TRAF-2 functionally within the NF-κB pathway, and may be explored as a potential target in AML.

Endoplasmic reticulum protein GliPR1 regulates G protein signaling and the cell cycle and is overexpressed in AML.

Glioma pathogenesis­related protein 1 (GliPR1) is a pleiotropic protein involved in cell proliferation, tumor growth and apoptosis. The aim of the present study was to further characterize GliPR1 in regard to its subcellular localization and its overall effect on cellular gene expression. Knockdown of GliPR1 and Affymetrix microarray mRNA expression analysis revealed 262 GliPR1­dependent differentially expressed genes, of which 40 were induced and 222 were suppressed. Differentially expressed genes were overrepresented in five Gene Ontology categories: G protein signaling pathways, regulation of cyclin­dependent protein kinase activity, ER to Golgi vesicle-mediated transport, axon guidance and dephosphorylation. GliPR1-EGFP fusion protein co­localized with the endoplasmic reticulum (ER) or with cytoplasmic vesicles as demonstrated by confocal microscopy. GliPR1 expression was found to be significantly increased in acute myeloid leukemia (AML) bone marrow samples, while markedly reduced in acute lymphoblastic leukemia, unchanged in myelodysplastic syndrome and slightly decreased in chronic lymphocytic leukemia as well as in chronic myelocytic leukemia (CML) when compared to normal samples. GliPR1 was localized and involved in the ER secretory protein pathway. GliPR1 affects G protein signaling and cell cycle regulation. Based on the observed overexpression in AML samples, GliPR1 should be further explored as a potential target for AML.

Knockdown of ERM family member moesin in host cells increases HIV type 1 replication.

Moesin is a member of the ERM (ezrin, radixin, moesin) family of cytoskeleton/membrane structure organizing and signal transduction proteins. Previously, we found an increased expression of moesin during HIV-1 infection. Moesin was also reported to be incorporated into HIV-1 virions. To analyze whether moesin is a host factor affecting the replication cycle of human immunodeficiency virus type 1 (HIV-1), we used small interfering RNAs (siRNAs) to evaluate the effect of moesin knockdown on HIV-1 replication in P4-CCR5 cells. Moesin's knockdown did not affect the cell viability or cell phenotype. Interestingly, we observed a marked increase in viral replication, as demonstrated by enhanced HIV-1 RNA, p24 antigen, and ß-galactosidase reporter expression. Moesin-dependent enhancement of HIV-1 replication was confirmed in lymphocytic host cells (Jurkat). These results suggest an overall rather restrictive role of moesin for HIV-1 replication in host cells in vitro.

Inhibition of X4-tropic HIV type 1 replication by knockdown of the cellular protein LEREPO4.

Human immunodeficiency virus 1 (HIV-1) and host cell factors show important mutual interactions. We found that HIV-1 infection induced expression of a likely ortholog of mouse immediate early response erythropoietin 4 (LEREPO4) in vitro. When LEREPO4 expression was suppressed by siRNA in P4-CCR5 cells, HIV-1 replication showed significantly reduced HIV-1 transcript and p24 protein levels as measured by quantitative PCR and ELISA, respectively. The LEREPO4 knockdown also had an inhibitory effect on HIV-1-LTR-driven reporter plasmid expression of ß-galactosidase. Furthermore, the inhibitory effect of LEREPO4 silencing on HIV-1 replication was confirmed in Jurkat T cells. The up-regulation of LEREPO4 by HIV-1 and the inhibition of HIV-1 replication mediated by knockdown of LEREPO4 may point to an important functional role of LEREPO4 as a novel HIV-1 dependency factor.

Randomized phase II trial of first-line treatment with sorafenib versus interferon Alfa-2a in patients with metastatic renal cell carcinoma.

PURPOSE: An open-label, phase II study to evaluate progression-free survival (PFS), overall best response, adverse events (AEs), and patient-reported outcomes with sorafenib versus interferon alfa-2a (IFN-alpha-2a) in patients with untreated, advanced renal cancer. PATIENTS AND METHODS: A total of 189 patients were randomly assigned to oral sorafenib 400 mg twice daily or to subcutaneous IFN-alpha-2a 9 million U three times weekly (period 1). Sorafenib patients who progressed were dose-escalated to 600 mg twice daily; IFN-alpha-2a patients who progressed were switched to sorafenib 400 mg twice daily (period 2). RESULTS: In period 1 PFS was similar for sorafenib-treated (n = 97; 5.7 months) and IFN-alpha-2a-treated patients (n = 92; 5.6 months); more sorafenib-treated patients had tumor shrinkage (68.2% v 39.0%). Common drug-related AEs (Grades > or = 3) for sorafenib were hand-foot skin reaction (11.3%), diarrhea (6.2%), and rash/desquamation (6.2%); for IFN-alpha-2a, these were fatigue (10.0%), nausea (3.3%), flu-like syndrome (2.2%), and anorexia (2.2%). Sorafenib-treated patients reported fewer symptoms, better quality of life (QOL), and greater treatment satisfaction. In period 2, 41.9% of patients who received sorafenib 600 mg twice daily (n = 43) experienced tumor reduction (median PFS, 3.6 months). After the switch to sorafenib 400 mg twice daily, tumors were reduced in 76.2% of 50 patients (median PFS, 5.3 months). AEs were mostly grade 1 to 2; no increase in AEs of grades > or = 3 occurred after sorafenib dose escalation. CONCLUSION: In this study, sorafenib resulted in similar PFS as IFN-alpha-2a in patients with untreated RCC. However, sorafenib-treated patients experienced greater rates of tumor size reduction, better QOL, and improved tolerability. Both dose escalation of sorafenib after progression and a switch to sorafenib after progression on IFN-alpha-2a resulted in clinical benefit.

Clinical significance of minimal residual disease quantification in adult patients with standard-risk acute lymphoblastic leukemia.

Adult patients with acute lymphoblastic leukemia (ALL) who are stratified into the standard-risk (SR) group due to the absence of adverse prognostic factors relapse in 40% to 55% of the cases. To identify complementary markers suitable for further treatment stratification in SR ALL, we evaluated the predictive value of minimal residual disease (MRD) and prospectively monitored MRD in 196 strictly defined SR ALL patients at up to 9 time points in the first year of treatment by quantitative polymerase chain reaction (PCR). Frequency of MRD positivity decreased from 88% during early induction to 13% at week 52. MRD was predictive for relapse at various follow-up time points. Combined MRD information from different time points allowed definition of 3 risk groups (P < .001): 10% of patients with a rapid MRD decline to lower than 10(-4) or below detection limit at day 11 and day 24 were classified as low risk and had a 3-year relapse rate (RR) of 0%. A subset of 23% with an MRD of 10(-4) or higher until week 16 formed the high-risk group, with a 3-year RR of 94% (95% confidence interval [CI] 83%-100%). The remaining patients whose RR was 47% (31%-63%) represented the intermediate-risk group. Thus, MRD quantification during treatment identified prognostic subgroups within the otherwise homogeneous SR ALL population who may benefit from individualized treatment.

Early molecular response to posttransplantation imatinib determines outcome in MRD+ Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL).

In adult Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL), minimal residual disease (MRD) after stem cell transplantation (SCT) is associated with a relapse probability exceeding 90%. Starting imatinib in the setting of MRD may decrease this high relapse rate. In this prospective multicenter study, 27 Ph+ ALL patients received imatinib upon detection of MRD after SCT. Bcr-abl transcripts became undetectable in 14 (52%) of 27 patients, after a median of 1.5 months (0.9-3.7 months) ((early)CR(mol)). All patients who achieved an (early)CR(mol) remained in remission for the duration of imatinib treatment; 3 patients relapsed after imatinib was discontinued. Failure to achieve polymerase chain reaction (PCR) negativity shortly after starting imatinib predicted relapse, which occurred in 12 (92%) of 13 patients after a median of 3 months. Disease-free survival (DFS) in (early)CR(mol) patients is 91% +/- 9% and 54% +/- 21% after 12 and 24 months, respectively, compared with 8% +/- 7% after 12 months in patients remaining MRD+ (P < .001). In conclusion, approximately half of patients with Ph+ ALL receiving imatinib for MRD positivity after SCT experience prolonged DFS, which can be anticipated by the rapid achievement of a molecular complete remission (CR). Continued detection of bcr-abl transcripts after 2 to 3 months on imatinib identifies patients who will ultimately experience relapse and in whom additional or alternative antileukemic treatment should be initiated.