Clinical characteristics and outcome of patients with combined hepatocellular-cholangiocarcinoma-a European multicenter cohort.

BACKGROUND: There is no clear consensus on the optimal systemic treatment regimen in combined hepatocellular-cholangiocarcinoma (cHCC-CCA) patients. We describe clinical characteristics and outcome of cHCC-CCA patients, with a special focus on patients receiving palliative systemic therapy, including immune checkpoint inhibitors (ICIs). METHODS: In this European retrospective, multicenter study, patients with histologically proven cHCC-CCA treated at four institutions between April 2003 and June 2022 were included. In patients receiving palliative systemic therapy, outcome was compared between cytotoxic chemotherapy (CHT)- and non-cytotoxic CHT (nCHT)-treated patients. RESULTS: Of 101 patients, the majority were male (n = 70, 69%) with a mean age of 64.6 ± 10.6 years. Only type of first-line treatment was independently associated with overall survival (OS). Palliative systemic therapy was administered to 44 (44%) patients. Of those, 25 (57%) patients received CHT and 19 (43%) had nCHT (n = 16 of them sorafenib) in systemic first line. Although there was no significant difference in overall response rate (ORR; CHT versus nCHT: 8% versus 5%), disease control rate (24% versus 21%), and median progression-free survival {3.0 months [95% confidence interval (CI) 1.4-4.6 months] versus 3.2 months (95% CI 2.8-3.6 months), P = 0.725}, there was a trend towards longer median OS in the CHT group [15.5 months (95% CI 8.0-23.0 months) versus 5.3 months (95% CI 0-12.5 months), P = 0.052]. However, in multivariable analysis, type of first-line regimen (CHT versus sorafenib) was not associated with OS. ORR in patients receiving ICIs (n = 7) was 29%. CONCLUSIONS: In patients with cHCC-CCA, OS, progression-free survival, ORR, and disease control rate were not significantly different between individuals receiving CHT and patients receiving nCHT. Immunotherapy may be effective in a subset of patients. Prospective studies are needed to identify optimal systemic treatment regimens in cHCC-CCA.

Ultrafast multi-cycle terahertz measurements of the electrical conductivity in strongly excited solids.

Key insights in materials at extreme temperatures and pressures can be gained by accurate measurements that determine the electrical conductivity. Free-electron laser pulses can ionize and excite matter out of equilibrium on femtosecond time scales, modifying the electronic and ionic structures and enhancing electronic scattering properties. The transient evolution of the conductivity manifests the energy coupling from high temperature electrons to low temperature ions. Here we combine accelerator-based, high-brightness multi-cycle terahertz radiation with a single-shot electro-optic sampling technique to probe the evolution of DC electrical conductivity using terahertz transmission measurements on sub-picosecond time scales with a multi-undulator free electron laser. Our results allow the direct determination of the electron-electron and electron-ion scattering frequencies that are the major contributors of the electrical resistivity.

Role of immunotherapy in the management of hepatocellular carcinoma: current standards and future directions.

The multikinase inhibitor sorafenib was the only approved systemic therapy in advanced hepatocellular carcinoma (hcc) for about a decade. In recent years, the number of approved agents has increased significantly as a result of a number of positive phase iii clinical trials. Lenvatinib as a first-line treatment, and regorafenib, cabozantinib, and ramucirumab in the second-line setting are now approved by the U.S. Food and Drug Administration (fda) and the European Medicines Agency. In phase ii studies, immunotherapy with nivolumab and monotherapy using pembrolizumab yielded impressive results for overall survival in therapy-naïve and pretreated patients, leading to the accelerated approval by the fda of nivolumab and pembrolizumab for second-line treatment. However, phase iii trials of nivolumab in the first line and pembrolizumab in the second line as single agents failed to reach statistical significance, although clinical benefit for a subset of patients with long durations of response could be demonstrated. Despite that setback, immunotherapy for hcc is a promising therapeutic approach, and the combination of immunotherapy with other treatment modalities such as monoclonal antibodies, tyrosine kinase inhibitors, or local therapies has the potential to increase the overall response rate and survival. Recently, the results of a phase iii trial of combination atezolizumab-bevacizumab compared with sorafenib showed a highly significant survival benefit and median overall survival that was not reached in the immunotherapy arm, making the combination the preferred standard of care in first-line therapy. Despite the impressive results and generally good toxicity profile of immunotherapy, patients who respond to therapy constitute only a subset of the overall population, and response rates are still limited. This review focuses on the currently reported results and ongoing clinical trials of checkpoint inhibitor-based immunotherapy in hcc.

Toward quasi-DC conductivity of warm dense matter measured by single-shot terahertz spectroscopy.

We present an experimental setup capable of measuring the near DC conductivity of laser generated warm dense matter using single-shot terahertz time-domain spectroscopy. The setup uses a reflective echelon and balanced detection to record THz waveforms with a minimum detectable signal of 0.2% in a single laser pulse. We describe details of the experimental setup and the data analysis procedure and present single-shot terahertz transmission data on aluminum that has been laser heated to an electron temperature of 0.5 eV.

Renal tubular epithelial cell-derived BAFF expression mediates kidney damage and correlates with activity of proliferative lupus nephritis in mouse and men.

B-cell activating factor of the tumour necrosis factor family (BAFF) is a cytokine, mainly produced by hematopoietic cells (e.g. monocytes/macrophages, dendritic cells), indispensable for B-cell maturation. The BLISS studies have demonstrated that blocking BAFF by the human monoclonal antibody belimumab is a valuable therapeutic approach in patients with clinically and serologically active systemic lupus erythematosus (SLE). However, the defined sources of BAFF, which contributes to SLE, are still unclear. Recent findings show that BAFF expression is not restricted to myeloid cells. Since lupus nephritis is the main cause of morbidity and mortality for SLE patients, the aim of this study was to investigate whether renal tubular epithelial cells (TEC) are an important source of BAFF and thus may contribute to the pathogenesis and progression of SLE. We found BAFF expression both in cultured murine and human TEC. These results could be verified with in situ data from the kidney. Moreover, BAFF expression in the kidneys of lupus-prone MRL- Faslpr mice correlated with disease activity, and BAFF expression on TEC in biopsies of patients with diffuse proliferative lupus nephritis showed a correlation with the histopathological activity index. In vitro functional assays revealed an autocrine loop of BAFF with its binding receptors on TEC, resulting in a strong induction of colony stimulating factor-1. Finally, we identified divergent effects of BAFF on TEC depending on the surrounding milieu ('inflammatory versus non-inflammatory'). Taken together, our findings indicate that renal-derived BAFF may play an important role in the pathophysiology of the systemic autoimmune disease SLE.

Safety and efficacy of outpatient parenteral antibiotic therapy in an academic infectious disease clinic.

WHAT IS KNOWN AND OBJECTIVE: Outpatient parenteral therapy (OPAT) has become a safe and effective modality for patients requiring intravenous or prolonged antimicrobial therapy since the 1970s. It is being increasingly utilized in various settings; however, studies evaluating the safety and efficacy of clinic-based OPAT are limited. Since 2012, patients being considered for OPAT have required an infectious disease (ID) consultation at our institution. Candidates receiving once-daily antimicrobials who were ineligible for home infusion or nursing home placement as determined by their insurance companies and those who preferred the clinic over nursing home or home infusion were referred to the ID clinic. This study assessed the safety and outcome of patients receiving OPAT in an academic inner-city ID clinic in Detroit, Michigan. METHODS: This was a retrospective cross-sectional study of electronic medical records of patients, identified through clinic records, who received at least 2 days of OPAT from December 2012 to December 2015. Demographics, types of infections, antimicrobial regimen used, adverse events and outcome were evaluated. RESULTS: A total of 122 cases were identified during the study period. Mean age was 62 years with 55% male; 102 (84%) of 122 patients had peripherally inserted central catheter (PICC). Fifty-five per cent of patients participated in the clinic-based OPAT programme for insurance reasons, and 43% preferred the clinic over nursing home or home infusion. The most common infections were bone and joint (36%), followed by skin and soft tissue (18%) and urinary tract infections (12%). Ertapenem (44%) and daptomycin (41%) alone or in combination were used most frequently with 40% of patients receiving at least 4 weeks of treatment. Thirteen patients (11%) experienced one or more adverse drug events on daptomycin and/or ertapenem; of these, nine (69%) patients were receiving daptomycin monotherapy. Gastrointestinal symptoms (29%), cramping and myalgias (29%) and asymptomatic creatine phosphokinase (CPK) elevation (24%) were the most common adverse events. Three (3%) of 102 patients had PICC-related complications. Fourteen (88%) of 16 patients with adverse events or PICC-related complications required changing or stopping antibiotics; two (2%) had infection-related readmission. Conversely, 113 (93%) of 122 patients who completed treatment were considered cured and none had treatment failure at the end of 30 days of treatment. No patients died as a result of treatment or infection-related complications. WHAT IS NEW AND CONCLUSION: Outpatient parenteral therapy in our academic ID clinic was a safe and effective alternative to home infusion or skilled nursing facilities for patients requiring long-term antibiotics with few adverse events and complications.

Coupled variable selection for regression modeling of complex treatment patterns in a clinical cancer registry.

For determining a manageable set of covariates potentially influential with respect to a time-to-event endpoint, Cox proportional hazards models can be combined with variable selection techniques, such as stepwise forward selection or backward elimination based on p-values, or regularized regression techniques such as component-wise boosting. Cox regression models have also been adapted for dealing with more complex event patterns, for example, for competing risks settings with separate, cause-specific hazard models for each event type, or for determining the prognostic effect pattern of a variable over different landmark times, with one conditional survival model for each landmark. Motivated by a clinical cancer registry application, where complex event patterns have to be dealt with and variable selection is needed at the same time, we propose a general approach for linking variable selection between several Cox models. Specifically, we combine score statistics for each covariate across models by Fisher's method as a basis for variable selection. This principle is implemented for a stepwise forward selection approach as well as for a regularized regression technique. In an application to data from hepatocellular carcinoma patients, the coupled stepwise approach is seen to facilitate joint interpretation of the different cause-specific Cox models. In conditional survival models at landmark times, which address updates of prediction as time progresses and both treatment and other potential explanatory variables may change, the coupled regularized regression approach identifies potentially important, stably selected covariates together with their effect time pattern, despite having only a small number of events. These results highlight the promise of the proposed approach for coupling variable selection between Cox models, which is particularly relevant for modeling for clinical cancer registries with their complex event patterns.

[Etiology and complications of liver cirrhosis: data from a German centre]. / Ätiologie und Komplikationen der Leberzirrhose: Daten eines deutschen Zentrums.

BACKGROUND: Liver cirrhosis develops as a terminal complication of chronic liver disease. The clinical course is determined by the underlying etiology and the accompanying risk factors, which are influenced by the geographic and cultural background. METHODS: A total of 236 patients (159 men, 77 women, median age 57 [22-81] years) were included for retrospective analysis between July 2012 and February 2014 using standardized questionnaires during an outpatient visit at a hepatology clinic. RESULTS: The most common etiologies of liver cirrhosis were related to alcohol consumption (52 %), chronic hepatitis C (28 %) or hepatitis B (14 %) infection and NASH (nonalcoholic steatohepatitis, 6 %). At the time of presentation 55 % patients had compensated cirrhosis corresponding to Child-Turcotte-Pugh (CTP) stage A, while 45 % were in a decompensated stage (30 % CTP B and 15 % CTP C). Subgroups were analyzed for the incidence of complications and the emergence of infections. Most frequently esophageal varices (60 %) and ascites (49 %) were observed, followed by pleural effusion (14 %), hepatic encephalopathy (25 %) or hepatorenal syndrome (18 %). 16 % of patients exhibited infection based on clinical criteria. An infective agent was isolated in 38 % of all cases with infection and of those 50 % were gram positive bacteria. In multivariate analysis only the presence of ascites was an independent risk factor for infection. CONCLUSION: Despite improved medical therapies for viral hepatitis, these were the most frequent causes of liver cirrhosis, closely followed by alcoholic cirrhosis. The observed complications included bacterial infection and complication related to portal hypertension.

Hepatitis B virus-specific T-cell responses during IFN administration in a small cohort of chronic hepatitis B patients under nucleos(t)ide analogue treatment.

The effect of pegylated interferon-α (IFN) add-on therapy on HBV-specific T-cell responses was evaluated in 12 patients with stable, undetectable hepatitis B virus (HBV) load under nucleos(t)ide analogue therapy. Peripheral blood mononuclear cells were isolated at week 0, 4, 8, 12, 24 and 48 of IFN add-on therapy. Quantity and quality of circulating HBV S- and core-specific CD4 and CD8 T cells were analysed ex vivo by flow cytometry. HBV S- and core-specific CD4 T-cell numbers modestly increased within 8 weeks of IFN administration (P = 0.0391 and P = 0.0195), whereas HBV-specific CD8 T cells in general showed only minor changes under IFN add-on therapy. Functionality of HBV-specific CD4 but not CD8 T cells positively correlated with serum transaminase activity. In addition, we observed an increase in CD4 T cells producing tumour necrosis factor-α (TNFα) without antigen restimulation (P = 0.0039), which correlated with elevated transaminases. During IFN add-on therapy, two patients developed an anti-HBs seroconversion, only one of whom showed a relevant increase in HBV-specific T cells. In conclusion, IFN add-on therapy of chronic hepatitis B increased HBV-specific T-cell responses and affected a previously unrecognized TNFα-monofunctional CD4 T-cell population. Although the observed T-cell responses did not correlate with HBsAg seroconversion, we expect additional insights into the immunopathogenesis of hepatitis B, following the characterization of the newly identified TNF α-monofunctional T-cell population.

[Therapy of hepatocellular carcinoma]. / Therapie des hepatozellulären Karzinoms.

Today, hepatocellular carcinoma (HCC) represents the leading cause of death in patients with liver cirrhosis; in most western countries the incidence is also expected to increase further. Due to insufficient surveillance of patients at risk, most cases are diagnosed in an intermediate to advanced stage, leading-together with the underlying liver cirrhosis-to limited therapeutic options and a dismal prognosis. Therefore, classification according to stage and interdisciplinary treatment decisions in experienced centers are of paramount importance to provide an individualized treatment plan when considering potentially curative (resection, liver transplantation, local ablation) and palliative (transarterial approaches, sorafenib) treatment options. There is hope that the prognosis of patients with HCC can be improved in the near future by better prevention, stringent surveillance, multimodality treatment approaches, and an expansion of personalized medicine.

Comparison of resection and transarterial chemoembolisation in the treatment of advanced intrahepatic cholangiocarcinoma--a single-center experience.

AIMS: The aim of this study is to evaluate factors associated with the outcome after surgical resection and to compare the efficacy of surgery to transarterial chemoembolisation (TACE) in patients with advanced intrahepatic cholangiocarcinoma (IHC). MATERIALS AND METHODS: 273 patients with IHC treated in our department between 1997 and 2012 were included in our study. Patients were divided according to therapy into surgical (n = 130), TACE (n = 32), and systemic chemotherapy/best supportive care (n = 111) groups. Clinicopathological characteristics and survival were reviewed retrospectively. RESULTS: The 1-, 3-, and 5-year survival rates in patients after surgical resection were 60%, 40%, and 23%, respectively. Recurrence occurred in 63 percent of patients after R0 resection. Median time of recurrence-free survival was 14 months. Univariate analysis revealed nine significant risk factors for overall survival in the resection group: major surgery, extrahepatic resection, vascular and bile duct resection, lymph node invasion, poor tumour differentiation, positive surgical margin, multiple lesions, tumour diameter, and UICC-Stage. Multivariate analysis showed that lymph node metastasis (P < 0.001), poor tumour differentiation (P = 0.002), and positive resection margins (P = 0.001) were independent prognostic factors for survival. Median survival as well as overall survival rates of TACE patients were comparable to those of lymph node positive patients and patients with tumour positive surgical margins. CONCLUSIONS: R0 resection in patients with negative lymph node status remains the best chance for long-term survival in patients with IHC. There is no significant survival benefit of surgery in lymph node positive patients or patients with positive resection margin over TACE.

Novel ways to sensitise gastrointestinal cancer to apoptosis.

Gastrointestinal (GI) cancers are major health problems, being the most common cancers worldwide. Resistance to apoptosis is closely linked to carcinogenesis and enables malignant cells to evade therapy-induced cell death. In the recent past, the increasing understanding of molecular pathways of apoptosis has provided novel targets in cancer therapy. Several drugs, either inhibiting antiapoptotic signalling or actively inducing apoptosis in cancer cells, have already entered clinical trials. Until now, agents targeting apoptosis pathways are primarily being tested alone or in combination with chemotherapy. In the near future, personalized combination therapies will probably be beneficial for patients with GI cancer. In this review, the current knowledge on defects in apoptosis signalling in GI cancer is summarised and the focus is on the potential clinical efficacy of apoptosis targeting agents.

The oral motor capacity and feeding performance of preterm newborns at the time of transition to oral feeding.

The objective of the present study was to determine the oral motor capacity and the feeding performance of preterm newborn infants when they were permitted to start oral feeding. This was an observational and prospective study conducted on 43 preterm newborns admitted to the Neonatal Intensive Care Unit of UFSM, RS, Brazil. Exclusion criteria were the presence of head and neck malformations, genetic disease, neonatal asphyxia, intracranial hemorrhage, and kernicterus. When the infants were permitted to start oral feeding, non-nutritive sucking was evaluated by a speech therapist regarding force (strong vs weak), rhythm (rapid vs slow), presence of adaptive oral reflexes (searching, sucking and swallowing) and coordination between sucking, swallowing and respiration. Feeding performance was evaluated on the basis of competence (defined by rate of milk intake, mL/min) and overall transfer (percent ingested volume/total volume ordered). The speech therapist's evaluation showed that 33% of the newborns presented weak sucking, 23% slow rhythm, 30% absence of at least one adaptive oral reflex, and 14% with no coordination between sucking, swallowing and respiration. Mean feeding competence was greater in infants with strong sucking fast rhythm. The presence of sucking-swallowing-respiration coordination decreased the days for an overall transfer of 100%. Evaluation by a speech therapist proved to be a useful tool for the safe indication of the beginning of oral feeding for premature infants.

BlotBase: a northern blot database.

With the availability of high-throughput gene expression analysis, multiple public expression databases emerged, mostly based on microarray expression data. Although these databases are of significant biomedical value, they do hold significant drawbacks, especially concerning the reliability of single gene expression profiles obtained by microarray data. Simultaneously, reliable data on an individual gene's expression are often published as single northern blots in individual publications. These data were not yet available for high-throughput screening. To reduce the gap between high-throughput expression data and individual highly reliable expression data, we designed a novel database "BlotBase", a freely and easily accessible database, currently containing approximately 700 published northern blots of human or mouse origin (http://www.medicalgenomics.org/Databases/BlotBase). As the database is open for public data submission, we expect this database to quickly become a large expression profiling resource, eventually providing higher reliability in high-throughput gene expression analysis. Realizing BlotBase, Pubmed was searched manually and by computer based text mining methods to obtain publications containing northern blot results. Subsequently, northern blots were extracted and expression values of different tissues calculated utilizing Image J. All data were made available through a user friendly web front end. The data may be searched by either full text search or list of available northern blots of a specific tissue. Northern blot expression profiles were displayed by three expression states as well as a bar chart, allowing for automated evaluation. Furthermore, we integrated additional features, e.g. instant access to the corresponding RNA sequence or primer design tools making further expression analysis more convenient. Finally, through a semiautomatic submission system this database was opened to the bioinformatics community.

The oral motor capacity and feeding performance of preterm newborns at the time of transition to oral feeding

The objective of the present study was to determine the oral motor capacity and the feeding performance of preterm newborn infants when they were permitted to start oral feeding. This was an observational and prospective study conducted on 43 preterm newborns admitted to the Neonatal Intensive Care Unit of UFSM, RS, Brazil. Exclusion criteria were the presence of head and neck malformations, genetic disease, neonatal asphyxia, intracranial hemorrhage, and kernicterus. When the infants were permitted to start oral feeding, non-nutritive sucking was evaluated by a speech therapist regarding force (strong vs weak), rhythm (rapid vs slow), presence of adaptive oral reflexes (searching, sucking and swallowing) and coordination between sucking, swallowing and respiration. Feeding performance was evaluated on the basis of competence (defined by rate of milk intake, mL/min) and overall transfer (percent ingested volume/total volume ordered). The speech therapist's evaluation showed that 33 percent of the newborns presented weak sucking, 23 percent slow rhythm, 30 percent absence of at least one adaptive oral reflex, and 14 percent with no coordination between sucking, swallowing and respiration. Mean feeding competence was greater in infants with strong sucking fast rhythm. The presence of sucking-swallowing-respiration coordination decreased the days for an overall transfer of 100 percent. Evaluation by a speech therapist proved to be a useful tool for the safe indication of the beginning of oral feeding for premature infants.

Histone deacetylase inhibition by valproic acid down-regulates c-FLIP/CASH and sensitizes hepatoma cells towards CD95- and TRAIL receptor-mediated apoptosis and chemotherapy.

Hepatocellular carcinoma (HCC) is highly resistant to chemotherapy, leading to a poor prognosis of advanced disease. Inhibitors of histone deacetylase (HDACi) induce re-differentiation in tumor cells and thereby re-establish sensitivity towards apoptotic stimuli. HDACi are entering the clinical stage of tumor treatment, and several substances are currently being tested in clinical trials to prove their efficacy in the treatment of leukemias and solid tumors. In this study, we investigated the impact of the HDACi valproic acid (VA) on TRAIL- and CD95-mediated apoptosis in hepatoma cells, as well as its sensitizing effect on a chemotherapeutic agent. Treatment of HepG2 cells with VA increased sensitivity to CD95-mediated apoptosis (4% apoptosis vs. 42%), and treatment with epirubicin (74% vs. 90% viability). Caspase-3 activity was significantly enhanced in cells treated with VA plus anti-CD95 antibodies compared to cells treated with antibodies alone. In parallel, VA strongly augmented the effect of TNF-related apoptosis-inducing ligand (TRAIL or Apo2 ligand) on HepG2 cells (10% vs. 58% apoptosis). VA induced down-regulation of cellular FLICE-inhibitory protein (c-FLIP/CASH, also known as Casper/iFLICE/FLAME-1/CLARP/MRIT/usurpin), providing a possible molecular mechanism underlying the increased sensitivity towards cell death-mediated apoptosis. HDAC inhibitors are a promising class for the treatment of leukemias. In addition, among other class members, VA deserves further evaluation as a treatment option for patients with advanced HCC.

Use of chromatin immunoprecipitation to clone novel E2F target promoters.

We have taken a new approach to the identification of E2F-regulated promoters. After modification of a chromatin immunoprecipitation assay, we cloned nine chromatin fragments which represent both strong and weak in vivo E2F binding sites. Further characterization of three of the cloned fragments revealed that they are bound in vivo not only by E2Fs but also by members of the retinoblastoma tumor suppressor protein family and by RNA polymerase II, suggesting that these fragments represent promoters regulated by E2F transcription complexes. In fact, database analysis indicates that all three fragments correspond to genomic DNA located just upstream of start sites for previously identified mRNAs. One clone, ChET 4, corresponds to the promoter region for beclin 1, a candidate tumor suppressor protein. We demonstrate that another of the clones, ChET 8, is strongly bound by E2F family members in vivo but does not contain a consensus E2F binding site. However, this fragment functions as a promoter whose activity can be repressed by E2F1. Finally, we demonstrate that the ChET 9 promoter contains a consensus E2F binding site, can be activated by E2F1, and drives expression of an mRNA that is upregulated in colon and liver tumors. Interestingly, the characterized ChET promoters do not display regulation patterns typical of known E2F target genes in a U937 cell differentiation system. In summary, we have provided evidence that chromatin immunoprecipitation can be used to identify E2F-regulated promoters which contain both consensus and nonconsensus binding sites and have shown that not all E2F-regulated promoters show identical expression profiles.

Down-regulation of TDT transcription in CD4(+)CD8(+) thymocytes by Ikaros proteins in direct competition with an Ets activator.

Ikaros is a unique regulator of lymphopoiesis that associates with pericentromeric heterochromatin and has been implicated in heritable gene inactivation. Binding and competition experiments demonstrate that Ikaros dimers compete with an Ets activator for occupancy of the lymphocyte-specific TdT promoter. Mutations that selectively disrupt Ikaros binding to an integrated TdT promoter had no effect on promoter function in a CD4(+)CD8(+) thymocyte line. However, these mutations abolished down-regulation on differentiation, providing evidence that Ikaros plays a direct role in repression. Reduced access to restriction enzyme cleavage suggested that chromatin alterations accompany down-regulation. The Ikaros-dependent down-regulation event and the observed chromatin alterations appear to precede pericentromeric repositioning. Current models propose that the functions of Ikaros should be disrupted by a small isoform that retains the dimerization domain and lacks the DNA-binding domain. Surprisingly, in the CD4(+)CD8(+) thymocyte line, overexpression of a small Ikaros isoform had no effect on differentiation or on the pericentromeric targeting and DNA-binding properties of Ikaros. Rather, the small isoform assembled into multimeric complexes with DNA-bound Ikaros at the pericentromeric foci. The capacity for in vivo multimer formation suggests that interactions between Ikaros dimers bound to the TdT promoter and those bound to pericentromeric repeat sequences may contribute to the pericentromeric repositioning of the inactive gene.

Nucleosome remodeling at the IL-12 p40 promoter is a TLR-dependent, Rel-independent event.

Lipopolysaccharide (LPS) induction of the gene encoding interleukin 12 p40 requires remodeling of a promoter-encompassing nucleosome and the Toll-like receptor (TLR)-mediated activation of a c-Rel-containing complex. Analysis of TLR4-mutant mice revealed that remodeling requires TLR signaling. However, Rel proteins and other proteins required for transcription of an integrated p40 promoter were insufficient for remodeling. c-Rel was also unnecessary for remodeling, as remodeling was observed in c-Rel-/- macrophages, which lack p40 transcripts. These results suggest that remodeling requires TLR signaling pathways that diverge from the c-Rel activation pathways. The factors that stimulate remodeling may represent, therefore, newly identified targets of TLR signaling and of agents that regulate inflammatory responses and TH1 development.