Structure-based improvement of the binding affinity and recognition specificity of peptide competitors to target pediatric IL-5R/IL-5 interaction by gluing halogen bonds at their complex interface

Human interleukin-5 (IL-5) cytokine mediates the development of eosinophils and is involved in a variety of immune inflammatory responses that play a major role in the pathogenesis of childhood asthma, leukemia, and other pediatric allergic diseases. The immunomodulatory cytokine functions by binding to its cognate cell surface receptor IL-5R in a sheet-by-sheet manner, which can be conformationally mimicked and competitively disrupted by a double-stranded cyclic AF18748 peptide. In this study, we systematically examined the co-crystallized complex structure of human IL-5R with AF18748 peptide and rationally designed a halogen bond to glue at the protein-peptide complex interface by substituting the indole moiety of AF18748 Trp13 residue with a halogen atom (X = F, Cl, Br, or I). High-level theoretical calculations imparted presence of the halogen bond between the oxygen atom (O) of IL-5R Glu58 backbone and the halogen atom (X) of AF18748 Trp13 side chain. Experimental assays confirmed that the halogen bond can promote peptide binding moderately or considerably. More importantly, the halogen bond not only enhances peptide affinity to IL-5R, but also improves peptide selectivity for its cognate IL-5R over other noncognate IL-R proteins. As might be expected, the affinity and selectivity conferred by halogen bond increase consistently in the order: H < F < Cl < Br < I. Structural modeling revealed that the halogen bond plus its vicinal π-cation-π stacking co-define a ringed noncovalent system at the complex interface, which involves a synergistic effect to effectively improve the peptide binding potency and recognition specificity.

Genome-wide identification and expression analysis of SlRR genes in response to abiotic stress in tomato

The cytokinin two-component signal transduction system (TCS) is involved in many biological processes, including hormone signal transduction and plant growth regulation. Although cytokinin TCS has been well characterized in Arabidopsis thaliana, its role in tomato remains elusive. In this study, we characterized the diversity and function of response regulator (RR) genes, a critical component of TCS, in tomato. In total, we identified 31 RR genes in the tomato genome. These SlRR genes were classified into three subgroups (type-A, type-B and type-C). Various stress-responsive cis-elements were present in the tomato RR gene promoters. Their expression responses under pesticide treatment were evaluated by transcriptome analysis. Their expression under heat, cold, ABA, salinity and NaHCO₃ treatments was further investigated by qRT-PCR and complemented with the available transcription data under these treatments. Specifically, SlRR13 expression was significantly upregulated under salinity, drought, cold and pesticide stress and was downregulated under ABA treatment. SlRR23 expression was induced under salt treatment, while the transcription level of SlRR1 was increased under cold and decreased under salt stress. We also found that GATA transcription factors played a significant role in the regulation of SlRR genes. Based on our results, tomato SlRR genes are involved in responses to abiotic stress in tomato and could be implemented in molecular breeding approaches to increase resistance of tomato to environmental stresses.

[Exploratory study on detection of drug resistance of Mycobacterium tuberculosis in sputum specimens by next-generation sequencing]

Objective: To compare the diagnostic performance of next-generation sequencing (NGS) detection methods in sputum samples and Mycobacterium tuberculosis strains, in order to explore the feasibility of the NGS method to detect drug resistance in sputum specimens. Methods: In this retrospective study, the sputum specimens and corresponding clinical isolates of 50 pulmonary tuberculosis patients admitted to Beijing Chest Hospital from January 2017 to December 2017 were collected. The gene mutations of katG, inhA, rpoB, embA, embB, rpsL, rrs, gyrA, gyrB and tlyA in sputum specimens and corresponding clinical isolates were detected by NGS method. The phenotypic drug susceptibility test (DST) of the strains was carried out by the proportion method. Using DST results as a reference, the sensitivity, specificity, positive predictive value and negative predictive value of the NGS method for clinical strains and sputum specimens, as well as the consistency statistic (Kappa) with phenotype DST were calculated respectively. The Chi-square test was used to compare the accuracy of the NGS testing in sputum samples and strain samples. Results: The results showed that rpoB(63.83%, 30/47) and rrs(57.45%, 27/47) were the most common mutated genes, followed by katG(46.81%, 22/47), rpsL(29.79%, 14/47), gyrA(27.66%, 13/47), embB(21.28%, 10/47), tlyA(12.77%, 6/47), gyrB(8.51%, 4/47), and inhA promoter(19.15%, 9/47), embA promoter region (12.77%, 6/47) mutation. when the NGS method was compared with the resistance phenotype of isoniazid, rifampicin, ethambutol, second-line injectable drugs (streptomycin, capreomycin, kanamycin, amikacin), levofloxacin, the sensitivity were 85.71%, 91.67%, 77.78%, 81.82%, 100.00%, 87.50%, 100.00%, 69.23%, and the specificity were 100.00%, 94.12, 87.50%, 89.47%, 97.06%, 96.97%, 94.29%, 89.29% in sputum samples, while in strain samples, the sensitivity were 92.86%, 100.00%, 81.82%, 86.96%, 88.89%, 80.00%, 100.00%, 85.71%. The specificity were 100.00%, 92.86%, 87.10%, 94.74%, 100.00%, 100.00%, 97.14%, 92.86%. Compared with the phenotypic drug susceptibility results, the NGS method has better detection performance for isoniazid, rifampicin, capreomycin, kanamycin, and amikacin in sputum specimens (Kappa≥0.75); while among the strains, the NGS method had a good detection performance for isoniazid, rifampicin, streptomycin, capreomycin, kanamycin, amikacin and levofloxacin (Kappa≥0.75). With the accuracy of the NGS method for detecting strains as a reference, there was no statistically significant difference in the accuracy of all drug resistance detected between strains and sputum specimens. Conclusions: This study showed that the NGS technology was effective in predicting the resistance of isoniazid, rifampicin, and second-line injectable drugs (capreomycin, kanamycin and amikacin) by detecting sputum samples and strain genotypes, suggesting the feasibility and potential of direct detection of sputum samples by the NGS method as an early detection method for drug resistance.

[Clinical characteristics and prognostic analyses of cervical neuroblastoma]

Objective: To determine the characteristics of cervical neuroblastoma and the effect of resection extent on survival and outcomes. Methods: We performed a retrospective review of 32 children with cervical neuroblastoma treated at Beijing Children's Hospital between April 2013 and August 2020. Data were collected from the medical record. The individualized therapy was designed based on staging and risk group. Based on the extent of resection, patients were divided into incomplete and complete resection groups. Event free and overall survival rates were compared between two groups using the Kaplan-Meier method. Results: The ages of patients ranged from 1 month to 81 months, with a median age of 11 months, including 7 males and 15 females. Twenty-nine patients (90.6%) presented with cervical painless mass. The average diameter of the primary tumors was (5.12±1.43) cm. Tumors were located in the parapharyngeal space in 25 cases (78.1%) and in the root of the neck in 7 cases (21.9%). None had MYCN amplification. According to International Neuroblastoma Staging System (INSS), 15 patients (46.9%) were identified as stage 1, 11 patients (34.3%) as stage 2B, 3 patients (9.4%) as stage 3 and 3 patients (9.4%) as stage 4. There were 12 patients (37.5%) at low risk, 17 patients (53.1%) at intermediate risk and 3 patients at high risk according to Children's Oncology Group (COG) risk classification system. All patients underwent tumor resection. Postoperatively Horner's syndrome occurred in 13 patients (40.6%), pneumonia in 9 patients (28.1%), pharyngeal dysfunction in 8 patients (25.0%) and transient hoarseness in 4 patients (12.5%). At a median follow-up of 36.5 months, the overall survival rate was 96.4%, with no significant difference between incomplete and complete resection groups (100.0% vs. 96.3%, χ²=0.19, P=0.667); the event free survival rate was 78.1%, with a significant difference between the two groups (40.0% vs. 85.2%, χ²=6.71, P=0.010). Conclusions: Primary cervical neuroblastoma has a young onset age, mostly in low and medium risk groups, and represents favorable lesions with good outcomes after multidisciplinary therapy. Less aggressive surgery with preservation of important structures is recommended. Complete resection should not be attempted if it would compromise vital structures.

An integrated analysis of the circRNA-miRNA-mRNA network reveals novel insights into potential mechanisms of cell proliferation during liver regeneration

Cell proliferation constitutes the fundamental process and driving force behind regrowth during liver regeneration (LR). However, it remains unclear how competing endogenous RNA (ceRNA) networks affect hepatocyte proliferation and liver regeneration. Therefore, this study was designed to explore an LR-specific ceRNA network, which regulates cell proliferation. Based on the microarray data of mRNAs, and high-throughput sequencing data of miRNAs and circRNAs from regenerating livers, this study initially applied known 1484 LR associated mRNAs to perform GO analysis, and then selected 169 LR associated mRNAs involved in cell proliferation and the cell cycle. Subsequently, 188 interactive miRNA-mRNA pairs and 5206 circRNA-miRNA pairs, respectively, were predicted using bioinformatics methods. Next, in view of the differential expressions of these ceRNAs during LR, 26 miRNA-mRNA pairs and 71 circRNA-miRNA pairs were applied to generate a circRNA-miRNA-mRNA regulatory network, and only 14 triple interactive groups were obtained based on the predicted inverse interactions among ceRNAs. Finally, circ_19698/miR-423-5p axis was demonstrated to promote cell proliferation by modulating the expression of MYC, CCNA2, and CCND1 in rat BRL-3A cells. This study suggests a potential regulatory mechanism of cell proliferation in regenerating livers, as well as a novel pathway for modulating ceRNA networks to promote liver regeneration.

Osteopontin promotes rat hepatocyte proliferation both in vitro and in vivo

Aim: This study aimed to examine the effects of osteopontin (OPN) on hepatocyte growth and liver regeneration (LR). Methods: A recombinant lentivirus expressing OPN and OPN-siRNAs were used to treat BRL-3A cells, while the adenovirus expressing OPN or OPN-targeted shRNA were applied for rat primary hepatocytes. Moreover, rrOPN and OPN-Ab were added to treat BRL-3A. Next, rrOPN was administrated into rat regenerating livers. Then in vitro and in vivo assays were performed to evaluate the biological function of OPN in hepatocyte growth and LR. Results: OPN overexpression facilitated proliferation and viability of BRL-3A cells and primary hepatocytes, while OPN silencing reversed these effects. Similarly, rrOPN stimulated cell cycle progression and viability, but OPN-Ab led to cell cycle arrest and decreased viability. OPN overexpression induced the expression of p-STAT3, p-AKT and CCND1, and OPN siRNA led to reduction of p-AKT and CCND1. Furthermore, rrOPN promoted the expression of p-STAT3 and p-AKT, while OPN-Ab and PI3K/Akt inhibitor LY294002 both inhibited the expressions of p-AKT and Bcl2. Moreover, LR rate, serum IL-6 and TNF-α, Ki-67⁺ proportion and the phosphorylation of STAT3, AKT and p65 were augmented by rrOPN treatment. Conclusion: OPN promotes hepatocyte proliferation both in vitro and in vivo through STAT3 and AKT signaling pathways.

Long-term outcomes from prophylactic or episodic treatment of haemophilia A: A systematic review

INTRODUCTION

Evaluating treatment success in patients with haemophilia A (HA) remains a vigorous debate, especially concerning the interpretation of results from clinical and observational research. The benefits of short-term prophylaxis are well established, but long-term outcomes, particularly related to humanistic and economic burden, are not as well understood.

AIM

We conducted a systematic literature review to evaluate the association of episodic or prophylactic bleed control with long-term clinical, humanistic and economic outcomes.

METHODS

Studies published in English between 1 January 2006 and 15 December 2016 were included. Participants had HA (with or without inhibitors), received prophylactic or episodic treatment and had at least 4 years of treatment or follow-up. Results were analysed qualitatively with descriptive findings.

RESULTS

A total of 2091 records were screened, resulting in 19 studies from 20 publications for inclusion. Most studies included children (84%), were limited to patients with severe disease (74%) and were conducted in Europe or North America (89%). Ten studies (53%) included patients with inhibitors. Median study follow-up ranged from 5 to 19 years. Long-term bleeding and haemarthrosis outcomes were consistently better for patients receiving prophylaxis, who also required fewer hospitalizations or surgeries. Health-related quality of life, functionality and productivity were generally more favourable in patients receiving prophylaxis. Quantitative comparisons were not feasible due to the lack of consistency in endpoint collection and reporting among studies.

CONCLUSION

This systematic review confirmed that the benefits of prophylactic treatment on short-term outcomes translate to broader long-term clinical, humanistic and economic benefits. Better harmonization of data collection and outcome assessments across both registries and clinical studies is needed to allow for effective comparisons across studies and across data sources.

Abstract P3-05-02: Immune profiling of paired primary and recurrent triple negative breast cancer

Background: Triple negative breast cancer (TNBC) is a heterogeneous disease with several molecular subtypes: basal-like1 (BL-1), basal-like 2 (BL-2), mesenchymal (M), and luminal androgen receptor (LAR). Molecular evolution of TNBC through chemotherapy selection pressure is well recognized but poorly understood. In addition, approximately 20% of TNBCs respond to PD-1 or PD-L1 inhibitors. It has been observed that heavily pre-treated patients may not respond well to immunotherapy. This study was carried out to perform immune profiling of paired primary and recurrent TNBC. Here we report the result of the first 10 paired tissue pilot analysis.

Methods: Twenty specimens were identified through an IRB-approved protocol via the City of Hope Biospecimen Repository (2002-2015). Two brain and one bone metastasis specimens were not included due to technical difficulty. Formalin-fixed paraffin embedded (FFPE) sample blocks were cut into 5-mm thick slides and labeled with the following antibodies: CD4, CD8, CD3, FOXP3, CD20, CD33, Pan-CK, and PD-1 using the multiplex IHC opal method. Image acquisition and cell counting were carried out using PerkinElmer Vectra automated quantitative pathology imaging system and inForm software analysis (PerkinElmer, Waltham, MA). mRNA expression profiling was performed using Affymetrix Human Genechip 2.0. Raw data were normalized and processed using Expression Console. Using Vanderbilt TNBC sub-classification tool, we have sub-classified the 20 primary and recurrent TNBC specimens. Tumor mutation burden (TMB) was generated through FoundationOne® platform.

Result: A total of 17 samples were analyzed (M, 5; LAR, 3; BL-1, 4; BL-2, 5). M-subtype had a significantly lower tumor-infiltrating CD3+ T cells (p=0.005), CD8+ T cells (p=0.024), CD4+ T cells (p=0.065) and CD4+FOXP3+ Treg cells (p=0.054), irrespective of the site of metastasis. CD20+ B cells were particularly enriched in BL-1 subtype (p=0.0013, 23.5% of 17 samples). Of 17 samples, 8 had TMB. Seven had low TMB (&lt;10 mut/Mb) and one had intermediate TMB (11 mut/Mb, LAR subtype). The tumor with intermediate TMB had the highest quantity of tumor-infiltrating CD3+ T cells, CD8+ T cells, CD8+PD1+ T cells, and CD4+FOXP3+PD1+ Treg cells compared to the 7 tumors with low TMB. Compared with recurrent tumors, primary tumors had a significantly higher percentage of tumor-infiltrating T cells (TIL). To validate multiplexed IHC results, these samples were evaluated by a licensed pathologist at City of Hope using the International TILs Working Group 2014 guidelines, and there was a good correlation between percent of TILs and CD3+ T cells by IHC approach.

Conclusion: To our knowledge, this is the first study linking tumor immune cell profiles with the TNBC 4 subtypes. Distinctive immune cell patterns were observed among 4 TNBC subtypes. M subtype had significantly lower TILs, which may indicate poor response to checkpoint inhibitors. Further analysis of a total of 50 paired TNBCs is currently underway.

Contact information: Yuan Yuan MD PhD, Email: yuyuan@coh.org

Citation Format: He T-F, Yost S, Schmolze D, Wang R, Rosario A, Tu T, Chu P, Lee P, Yuan Y. Immune profiling of paired primary and recurrent triple negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-05-02.

Abstract P1-05-26: Genomic analysis of molecular discordance of paired primary and recurrent triple negative breast cancer

Background: Triple negative breast cancer (TNBC) is a heterogeneous disease with several molecular subtypes: basal-like1 (BL1), basal-like 2 (BL-2), mesenchymal(M), mesenchymal-stem-like(MSL), immune-modulatory(IM) and unclassified (UNC) Molecular evolution of TNBC through chemotherapy selection pressure is well recognized but poorly understood. This study was carried out to perform paired genomic analysis of TNBC comparing primary breast cancer with recurrent/refractory disease. Here we report the result of the first10 paired tissue analysis.

Methods: 49 paired specimens were identified through an IRB-approved protocol via COH biorepository search (2002- 2015). miRNA and mRNA profiling of 22 samples were performed. The miRNA libraries were prepared and sequenced on Hiseq2500. Sequences were aligned to hg19 genome and miRNA expression levels were counted by in house built R scripts. Go and pathway annotation was performed using DAVID online tool. Affymetrix human Genechip 2.0st was used for mRNA expression profiling. Raw data were normalized and processed using Expression Console, and linear regression was performed using Limma to identify the differentially expressed genes between primary and recurrent/refractory TNBCs.

Result: Through mRNA profiling, we identified several unique gene expression patterns comparing the paired TNBC. Significant mRNA expression alterations were observed in: cell cycle, DNA repair and adhesion. Using Vanderbilt TNBC sub-classification tool, we have identified “phenotype shift” between primary and recurrent TNBCs. Of the 8 paired specimen analyzed, 3 paired tissue remain in the same subclass (2 in IM, 1 in M). Phenotype shift observed in: 1 from BL1 to BL2, 1 from BL2 to BL1, 1 UNC to IM; 1 MSL to UNC; 1 from M to UNC. 15 up regulated and 13 down regulated miRNAs were identified. Most significantly differentially expressed miRNA (with more than 4 fold expression changes, P-value &lt; 0.001) included: miR-206, miR-203, miR-144, miR-16-2, miR-15b, and miR-20b (un-regulated) and miR-10b, miR-125b and let-7c(down-regulated). These miRNA genes are involved in regulation of hormonal receptor signaling, cell cycle, proliferation and metastases. Statistically significant differentially expressed miRNAs identified from our TNBC patient cohort will be further validated using RT-PCR.

Conclusion: A number of mRNA gene pathways and miRNAs showed differential expression between paired recurrent and primary TNBC tumor specimen. The underlying biology driven the phenotype shift is being studied. Further analysis to include a total of 49 paired TNBCs is currently underway.

Contact information: Yuan Yuan MD PhD, Email: yuyuan@coh.org.

Citation Format: Yuan Y, Li A, Yost S, Yuan Y-C, Chu P, Warden C, Wang J, Liu Z, Liang Y, Goldstein L, Wu X. Genomic analysis of molecular discordance of paired primary and recurrent triple negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-05-26.

Long non-coding RNAs expression profiles in hepatocytes of mice after hematopoietic stem cell transplantation

Hepatic veno-occlusive disease (HVOD), one serious complication following hematopoietic stem cell transplantation (HSCT), is mainly initiated by the damage to sinusoidal endothelial cells and hepatocytes. Long non-coding RNAs (lncRNAs) play an important role in the proliferation of hepatocytes and liver regeneration. lncRNAs profile in hepatocytes post-HSCT remains unclear. The aim of this study is to evaluate the profile of lncRNAs in hepatocytes of mice after HSCT. Mice HSCT model was established through infusion of 5 × 10(6) bone marrow mononuclear cells. On day 7, 14 and 33 after HSCT, mice were sacrificed for analysis of liver pathology, function and index. Total RNA was extracted from hepatocytes of mice on day 14 for microarray analysis of the expression profiles of lncRNAs by Arraystar Mouse lncRNA Microarray v2.0. Obvious edema and spotty necrosis of hepatocytes with inflammatory cells infiltration were observed post-HSCT. Meanwhile, increased levels of alkaline phosphatase, aspartate transaminase, and total bilirubin, as well as elevated liver index were also found. 2,918 up-regulated and 1,911 down-regulated lncRNAs in hepatocytes were identified. Some of differentially expressed mRNAs had adjacent lncRNAs that were also significantly dysregulated, with the same dysregulation direction. T-cell receptor (up-regulation) and VEGF signaling pathway (down-regulation) were identified as one of the most enriched pathways. Dysregulated lncRNAs might be involved in hepatocytes damage after HSCT, suggesting targeting them might be a novel approach in amelioration of hepatocytes damage.

Busulfan and cyclosphamide induce liver inflammation through NLRP3 activation in mice after hematopoietic stem cell transplantation

The aim of this study was to evaluate the role of NLRP3 inflammasome on BU/CY-induced liver inflammation in mice after HSCT. HSCT mice model was established through infusion of 5 × 10⁶ bone marrow mononuclear cells after conditioned with BU/CY. On day 7, 14, 21 and 28 after HSCT, mice were sacrificed for analysis of liver inflammation, cytokine secretion, NLRP3 expression and caspase-1 activation as well as release of ATP and high-mobility group protein B1 (HMGB1). Furthermore, NLRP3 selective inhibitor (BAY 11-7082) was administrated into mice after HSCT to evaluate its effects on liver inflammation. Severe liver inflammation and damage with elevated secretion of IL-1β and IL-18 were found in mice after HSCT. Meanwhile, elevated expressions of NLRP3 and caspase-1 activation in liver were found. In addition, increased release of ATP and HMGB1 were observed. Selective inhibition of NLRP3 decreased caspase-1 activation and secretion of IL-1β and IL-18. Furthermore, NLRP3 inhibition also reduced infiltration of macrophages and neutrophils and improved liver function. In conclusion, NLRP3 was involved in BU/CY-induced liver inflammation after HSCT and selectively inhibited it ameliorated liver inflammation and improved liver function, suggesting targeting NLRP3 might be a new approach in the prophylaxis of liver inflammation after HSCT.

Infusion of endothelial progenitor cells ameliorates liver injury in mice after haematopoietic stem cell transplantation

BACKGROUND & AIMS

Injury to liver sinusoidal endothelial cells (LSECs) is thought to be the initial factor for Hepatic veno-occlusive disease, a severe complication after haematopoietic stem cell transplantation (HSCT). Endothelial progenitor cells (EPCs) have the capacity to differentiate into endothelial cells and play a critical role in vasculogenesis, tissue regeneration and repair. Whether EPCs infusion ameliorates LSECs injury remains unclear. The aim of this study was to evaluate the effects of EPCs on liver injury in mice after HSCT.

METHODS

Mice received HSCT without or with EPCs infusion (HSCT + EPCs). Untreated mice were used as control. Liver and whole blood were collected post HSCT and used for the analysis of pathology of liver sinusoidal endothelial cells (LSECs) and hepatocytes, liver ultrastructure, function, level of IL-6, TNF-α and platelet activation.

RESULTS

Severe LSECs injury, hepatocyte damage, abnormal liver function was observed in HSCT group. In addition, increased P-selectin expression and secretion of IL-6, TNF-α was also found. However, all the above changes were alleviated in HSCT + EPCs at all the time points and normalized at the endpoint. Meanwhile, EPCs-induced repair of LSECs and hepatocytes was totally inhibited by the addition of anti-VE-cadherin antibody.

CONCLUSIONS

EPCs infusion ameliorated the damage to LSECs and hepatocytes as well as reduced secretion of IL-6, TNF-α and inhibited platelet activation after HSCT, leading to improved liver function, suggesting EPCs might be a new therapeutic strategy in the prophylaxis of liver injury after HSCT.

Blockage of caspase-1 activation ameliorates bone marrow inflammation in mice after hematopoietic stem cell transplantation

Conditioning regimens before hematopoietic stem cell transplantation (HSCT), cause damage to bone marrow and inflammation. Whether inflammasomes are involved in bone marrow inflammation remains unclear. The study aims to evaluate the role of inflammasomes in bone marrow inflammation after HSCT. On days 7, 14, 21 and 28 after HSCT, mice were sacrificed for analysis of bone marrow inflammation, pro-inflammatory cytokines secretion, inflammasomes expression and caspase-1 activation. Bone marrow inflammation with neutrophils and macrophages infiltration was observed after HSCT. Secretion of IL-1β, IL-18, TNF-α and IL-6 were elevated, with increased caspase-1 activation and inflammasomes expression. Caspase-1 inhibitor administration after HSCT significantly reduced infiltration of neutrophils and macrophages into bone marrow and increased the numbers of megakaryocytes and platelets. In conclusion, inflammasomes activation is involved in bone marrow inflammation after HSCT and caspase-1 inhibition attenuates bone marrow inflammation and promoted hematopoietic reconstitution, suggesting targeting caspase-1 might be beneficial for improving HSCT outcomes.

Real-space anisotropic dielectric response in a multiferroic skyrmion lattice

A magnetic skyrmion lattice is a microstructure consisting of hexagonally aligned skyrmions. While a skyrmion as a topologically protected carrier of information promises a number of applications, an easily accessible probe of the skyrmion and skyrmion lattice at mesoscopic scale is of significance. It is known that neutron scattering, Lorentz transmission electron microscopy, and spin-resolved STM as effective probes of skyrmions have been established. In this work, we propose that the spatial contour of dielectric permittivity in a skyrmion lattice with ferromagnetic interaction and in-plane (xy) Dzyaloshinskii-Moriya (DM) interaction can be used to characterize the skyrmion lattice. The phase field and Monte Carlo simulations are employed to develop the one-to-one correspondence between the magnetic skyrmion lattice and dielectric dipole lattice, both exhibiting the hexagonal symmetry. Under excitation of in-plane electric field in the microwave range, the dielectric permittivity shows the dumbbell-like pattern with the axis perpendicular to the electric field, while it is circle-like for the electric field along the z-axis. The dependences of the spatial contour of dielectric permittivity on external magnetic field along the z-axis and dielectric frequency dispersion are discussed.

Assessment, validation and deployment strategy of a two-barcode protocol for facile genotyping of duckweed species

Lemnaceae, commonly called duckweeds, comprise a diverse group of floating aquatic plants that have previously been classified into 37 species based on morphological and physiological criteria. In addition to their unique evolutionary position among angiosperms and their applications in biomonitoring, the potential of duckweeds as a novel sustainable crop for fuel and feed has recently increased interest in the study of their biodiversity and systematics. However, due to their small size and abbreviated structure, accurate typing of duckweeds based on morphology can be challenging. In the past decade, attempts to employ molecular barcoding techniques for species assignment have produced promising results; however, they have yet to be codified into a simple and quantitative protocol. A study that compiles and compares the barcode sequences within all known species of this family would help to establish the fidelity and limits of this DNA-based approach. In this work, we compared the level of conservation between over 100 strains of duckweed for two intergenic barcode sequences derived from the plastid genome. By using over 300 sequences publicly available in the NCBI database, we determined the utility of each of these two barcodes for duckweed species identification. Through sequencing of these barcodes from additional accessions, 30 of the 37 known species of duckweed could be identified with varying levels of confidence using this approach. From our analyses using this reference dataset, we also confirmed two instances where mis-assignment of species has likely occurred. Potential strategies for further improving the scope of this technology are discussed.

Myelitis in systemic lupus erythematosus frequently manifests as longitudinal and sometimes occurs at low disease activity

Background

Transverse myelitis (TM) is a relatively infrequent but severe complication in systemic lupus erythematosus (SLE). Owing to its rarity and unfavorable outcome, we investigated its general features on MRI and incidence in the context of lupus activity, to facilitate early recognition and treatment.

Methods

We report a case of a young man with clinically inactive lupus nephritis but who presented with a sudden attack of myelitis. We performed systematic literature search in Medline to study the clinical features of SLE-related TM.

Results

From 1960 to April 2013, a total of 72 articles containing 194 cases of lupus myelitis were found. Among acquired articles, 93 patients fulfilled the inclusion criteria. The majority of the cases (88.8%) were female. Longitudinal myelitis was the predominant imaging finding on MRI (71.4%, 45/63). Nearly two-thirds (61/94) of lupus myelitis occurred in association with active lupus, and one-third (33/94) occurred in low disease activity.

Conclusions

Upon literature review, we found myelitis in SLE more frequently manifested as longitudinal on MRI. Although lupus myelitis often presented at an active phase of SLE, one-third of events happened in the presence of low disease activity. Early initiation of effective immunosuppressive therapy facilitated recovery.

Kinetics of 90° domain wall motions and high frequency mesoscopic dielectric response in strained ferroelectrics: a phase-field simulation

The dielectric and ferroelectric behaviors of a ferroelectric are substantially determined by its domain structure and domain wall dynamics at mesoscopic level. A relationship between the domain walls and high frequency mesoscopic dielectric response is highly appreciated for high frequency applications of ferroelectrics. In this work we investigate the low electric field driven motion of 90°-domain walls and the frequency-domain spectrum of dielectric permittivity in normally strained ferroelectric lattice using the phase-field simulations. It is revealed that, the high-frequency dielectric permittivity is spatially inhomogeneous and reaches the highest value on the 90°-domain walls. A tensile strain favors the parallel domains but suppresses the kinetics of the 90° domain wall motion driven by electric field, while the compressive strain results in the opposite behaviors. The physics underlying the wall motions and thus the dielectric response is associated with the long-range elastic energy. The major contribution to the dielectric response is from the polarization fluctuations on the 90°-domain walls, which are more mobile than those inside the domains. The relevance of the simulated results wth recent experiments is discussed.

Wang-Landau sampling with logarithmic windows for continuous models

We present a modified Wang-Landau sampling (MWLS) for continuous statistical models by partitioning the energy space into a set of windows with logarithmically shrinking width. To demonstrate its necessity and advantages, we apply this sampling to several continuous models, including the two-dimensional square XY spin model, triangular J1-J2 spin model, and Lennard-Jones cluster model. Given a finite number of bins for partitioning the energy space, the conventional Wang-Landau sampling may not generate sufficiently accurate density of states (DOS) around the energy boundaries. However, it is demonstrated that much more accurate DOS can be obtained by this MWLS, and thus a precise evaluation of the thermodynamic behaviors of the continuous models at extreme low temperature (kBT<0.1) becomes accessible. The present algorithm also allows efficient computation besides the highly reliable data sampling.

P4-07-12: Identification of p53 Mutation in Whole Genome DNA from Single Circulating Tumor Cells (CTCs) and Primary Breast Cancers (BC) from Patients (pts) with Metastatic Breast Cancer (MBC)

Background: CTCs represent the source of distant metastases, and are also implied in the growth/re-growth of primary BC. Molecular/gene-level characterization of similarities and discordances between CTCs and BCs in pts with MBC may provide useful information for individualized treatment. Since somatic p53 mutations are frequently observed in primary BCs, we set out to assess the feasibility of identifying such mutations in CTCs from pts with MBCs, and compare the findings with those of the primary BCs from the same pts. Material and Method: Fiber-optic Array Scanning Technology (FAST) was used for identification and location of CTCs on large glass substrates. CTCs were identified after blood samples (10 ml) from MBC pts were stained to detect CTCs via automated digital microscopy by morphology, based on immunofuorescence staining for cytokeratin and nucleus, and the absence of CD45. Single CTCs from 10 pts with MBC were identified and removed from the glass substrates. DNA was extracted, and the whole genome of isolated CTCs was amplified by using whole genome amplification method (Sigma). P53 mutations in exon 5, exon 6, exon 7 and exon 8 were assessed. As comparison, genomic DNA from formalin-fixed and paraffin-embedded (FFPE) from primary BCs of the same pts, was amplified using the same method.

Results: p53 mutations were found in 8 out of 10 CTCs, and in 4 out of 10 in primary BC samples. Of 8 mutations detected in CTCs, one silent mutation and 7 missense mutations were seen. One particular point mutation, R181L, previously assessed as functional mutation, was observed in 4 out of 8 CTCs. None of the 4 mutations (a silent mutation, one missense mutation and two different deletions) detected in tumor samples were found in CTCs. We validated that the mutations detected in CTCs were not artifacts occurring during genome amplification, by comparing p53 mutations between unamplified tumor genomic DNA vs. amplified samples.

Conclusion: Whole genome amplification based on extracting DNA from single CTCs using FAST, and identification of mutations such as those in p53, is feasible. The quantitative and qualitative discordance in detecting p53 mutations between CTCs and primary BCs may be due to CTCs acquiring new -possibly epithelial-mesenchymal transition-like-characteristics with metastatic potential as they evolve from the primary tumors or metastatic sites, or, technical issues (analyzing FFPE-preserved vs. CTCs, tumor heterogeneity) may contribute to our findings. Further assessment of the functionality of high frequent functional mutations such as R181L is warranted.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-07-12.

Metallization of GaN Thin Films Prepared by Ion Beam Assisted Molecular Beam Epitaxy

Gallium nitride has generated much interest due to its ability to emit light in the blue to UV range [1]. We have investigated the ohmic contact properties of various metals evaporated onto highly auto-doped n-type GaN thin films which were grown on basal sapphire substrates by ion-assisted molecular beam epitaxy (IAMBE). Electrical measurements of transmission line structures with the metals In, InSn and AuGeNi revealed a wide range of contact resistivity (10∼2 to 10-6 Ω-cm2) which changed with annealing.

Formation of Silicon on Insulator (Soi) With Separation by Plasma Implantation of Oxygen (Spimox)

Buried oxide layers in Si were fabricated using non-mass analyzed plasma immersion ion implantation (PHI). We call this process of making separation by implantation of oxygen (SIMOX) with implantation by PIII as separation by plasma implantation of oxygen (SPIMOX). The implantation was carried out by applying a large negative bias to a Si wafer immersed in an oxygen plasma and a nominal dose of 2 × 1017 cm”2 of oxygen was obtained in less than three minutes. Cross section transmission electron microscopy (XTEM) and Rutherford backscattering spectrometry (RBS) were used to characterize the wafers. Three distinct modes of microstructure development were observed after post implantation annealing. With a low oxygen dose (< 1 × 1017 cm”2 ), isolated silicon dioxide precipitates did not grow large enough to form a continuous oxide layer. With a high oxygen dose ( > 3 × 1017 cm”2 ), however, a single buried oxide layer was observed. By optimizing the concentration ratio of 0+ and 02+ in the plasma and the implant dose, a double oxide layer (Si/oxide/Si/oxide/Si) structure, was produced in a single implantation step.

Rituximab for the treatment of relapsed or refractory stage III or IV follicular non-Hodgkin's lymphoma

This paper presents a summary of the evidence review group report into the clinical effectiveness and cost-effectiveness of rituximab for the treatment of relapsed or refractory stage III or IV follicular non-Hodgkin's lymphoma (NHL), in accordance with the licensed indication, based upon the evidence submission from Roche Products Ltd to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The submitted clinical evidence included two randomised controlled trials [European Organisation for Research and Treatment of Cancer (EORTC) and German Low Grade Lymphoma Study Group - Fludarabine, Cyclophosphamide and Mitoxantrone and (GLSG-FCM)] comparing the clinical effects of chemotherapy with or without rituximab in the induction of remission at first or second relapse and the clinical benefits of rituximab maintenance therapy versus the NHS's current clinical practice of observation for follicular lymphoma (FL) patients. Both trials showed that in patients with relapsed FL the addition of rituximab to chemotherapy induction treatment increased overall response rates. Furthermore, rituximab maintenance therapy increased the median length of remission when compared with observation only. Safety data from the two trials showed that while the majority of patients reported some adverse events, the number of patients withdrawing from treatment in the EORTC trial was low, with rates not being reported for the GLSG-FCM trial. The most commonly reported adverse events were blood/bone marrow toxicity, skin rashes and allergies. The ERG reran the manufacturer's economic model after altering several of the assumptions and parameter values in order to recalculate the cost-utility ratios, quality-adjusted life-years (QALYs) and estimates of benefits. The manufacturer reported that maintenance therapy with rituximab was cost-effective compared with observation against commonly applied thresholds, with an incremental cost-effectiveness ratio of 7721 pounds per QALY gained. The greatest clinical effectiveness is achieved by R-CHOP followed by rituximab maintenance (R-CHOP>R) and this treatment strategy had the greatest probability of being cost-effective for a QALY of approximately 18,000 pounds or greater. The guidance issued by NICE as a result of the STA states that in people with relapsed stage III or IV follicular NHL, rituximab is now an option in combination with chemotherapy to induce remission or alone as maintenance therapy during remission. Rituximab monotherapy is also an option for people with relapsed or refractory disease when all alternative treatment options have been exhausted.

Rituximab for the treatment of relapsed or refractory stage III or IV follicular non-Hodgkin’s lymphoma

This paper presents a summary of the evidence review group report into the clinical effectiveness and cost-effectiveness of rituximab for the treatment of relapsed or refractory stage III or IV follicular non-Hodgkin’s lymphoma (NHL), in accordance with the licensed indication, based upon the evidence submission from Roche Products Ltd to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The submitted clinical evidence included two randomised controlled trials [European Organisation for Research and Treatment of Cancer (EORTC) and German Low Grade Lymphoma Study Group – Fludarabine, Cyclophosphamide and Mitoxantrone and (GLSG-FCM)] comparing the clinical effects of chemotherapy with or without rituximab in the induction of remission at first or second relapse and the clinical benefits of rituximab maintenance therapy versus the NHS’s current clinical practice of observation for follicular lymphoma (FL) patients. Both trials showed that in patients with relapsed FL the addition of rituximab to chemotherapy induction treatment increased overall response rates. Furthermore, rituximab maintenance therapy increased the median length of remission when compared with observation only. Safety data from the two trials showed that while the majority of patients reported some adverse events, the number of patients withdrawing from treatment in the EORTC trial was low, with rates not being reported for the GLSG-FCM trial. The most commonly reported adverse events were blood/bone marrow toxicity, skin rashes and allergies. The ERG reran the manufacturer’s economic model after altering several of the assumptions and parameter values in order to recalculate the cost–utility ratios, quality-adjusted life-years (QALYs) and estimates of benefits. The manufacturer reported that maintenance therapy with rituximab was cost-effective compared with observation against commonly applied thresholds, with an incremental cost-effectiveness ratio of £7721 per QALY gained. The greatest clinical effectiveness is achieved by R-CHOP followed by rituximab maintenance (R-CHOP > R) and this treatment strategy had the greatest probability of being cost-effective for a QALY of approximately £18,000 or greater. The guidance issued by NICE as a result of the STA states that in people with relapsed stage III or IV follicular NHL, rituximab is now an option in combination with chemotherapy to induce remission or alone as maintenance therapy during remission. Rituximab monotherapy is also an option for people with relapsed or refractory disease when all alternative treatment options have been exhausted.

Prognostic relevance of ribonucleotide reductase small subunit p53R2 in pancreatic cancer

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Background: Pancreatic cancer has the worst survival of any solid tumor, with most patients presenting with metastatic disease. Even after surgical resection the median survival is only 20 months suggesting micrometastatic disease. Ribonucleotide reductase is a critical enzyme in DNA synthesis and repair. Previous studies have shown that ribonucleotide reductase M2 (RRM2) subunit is associated with invasion and metastasis. Even though p53R2 has 80% homology to RRM2, its role is quite different. Here we report on the prognostic relevance of p53R2 in pancreatic cancer. Methods: Archived pathology specimens were obtained from 30 patients and immunohistochemistry for p53R2 performed on an IRB approved protocol (#06253). Clinical data was obtained by chart review and log-rank and Cox hazard proportional models were used to analyze overall and disease-free survival. Cell culture analysis was performed to further evaluate the role of p53R2. Utilizing a Matrigel chamber, invasive MiaPaCa-2 cells were collected for comparison to parental cells. Results: The median overall survival (OS) was 13.2 months (p53R2+) vs 8.5 months (p53R2-) (p=0.01). Disease free survival (DFS) was 12.4 vs 8.5 months respectively (p<0.05). By Western analysis, invasive cells have a higher protein level of RRM2 compared to parental cells. Interestingly, the protein level of p53R2 was low in the invasive cells suggesting an opposing role. To confirm this we inhibited p53R2 using siRNA which enhanced the migration ability of Mia PaCa-2 cells. Conclusions: Patients with p53R2 expression have improved disease-free and overall survival suggesting this may be used as a prognostic marker in pancreatic cancer patients.

No significant financial relationships to disclose.

Deferasirox for the treatment of iron overload associated with regular blood transfusions (transfusional haemosiderosis) in patients suffering with chronic anaemia: a systematic review and economic evaluation

OBJECTIVES

To assess the clinical effectiveness and cost-effectiveness of deferasirox for the treatment of iron overload associated with regular blood transfusions in patients with chronic anaemia such as beta-thalassaemia major (beta-TM) and sickle cell disease (SCD).

DATA SOURCES

Electronic databases were searched up to March 2007.

REVIEW METHODS

Methods followed accepted procedures for conducting and reporting systematic reviews and economic evaluations.

RESULTS

A total of 14 randomised controlled trials (RCTs) involving a study population of 1480 (ranging from 13 to 586) met the inclusion criteria. There was a high degree of heterogeneity between trials in terms of trial design and outcome reporting. As such it was only possible to meta-analyse serum ferritin data from six trials making comparisons between deferiprone and DFO and combination therapy and DFO. Only one of the results was statistically significant, favouring combination therapy over DFO alone for serum ferritin at 12 months. How this translates into iron loading in organs such as the heart is unclear, nor was it possible to determine the long-term benefits of chelation therapy. Eight full economic evaluations (one full paper; seven abstracts) were included in the review. The results were generally consistent and appear to demonstrate the cost-effectiveness of deferasirox compared with DFO for the treatment of iron overload in a number of different patient populations and study locations. However, a number of assumptions and, in the case of the long-term studies, extrapolation from short-term RCT data were required, which render the results highly speculative at best. Because of the paucity of long-term data we developed a simple, short-term (1 year) model to assess the costs and benefits of deferasirox, deferiprone and DFO in patients with beta-TM and SCD from an NHS perspective. A number of assumptions were required to generate results and, as such, they should be interpreted as indicative rather than factual. Our model suggests that deferasirox may be a cost-effective strategy compared with DFO, at a cost per quality-adjusted life-year (QALY) below 30,000 pounds per year, for patients with beta-TM and SCD. However, this is highly dependent upon the age of the patient and the use and benefits of balloon infusers to administer DFO. Deferasirox compared with deferiprone is likely to be cost-effective only for young children. Furthermore, if deferiprone is proven to offer the same health benefits as deferasirox, the latter will not be cost-effective for any patient compared with deferiprone.

CONCLUSIONS

In the short term there is little clinical difference between any of the three chelators in terms of removing iron from the blood and liver. Deferasirox may be cost-effective compared with DFO in patients with beta-TM and SCD, but it is unlikely to be cost-effective compared with deferiprone. Elucidating the long-term benefits of chelation therapy, including issues of adverse events and adherence, should be the primary focus for future research. Future work should aim for consistency and transparency in reporting study design and results to aid decision-making when making comparisons across trials.

Molecular profiling including epidermal growth factor receptor and p21 expression in high-risk breast cancer patients as indicators of outcome

BACKGROUND

Patients with high-risk primary breast cancer remain at high risk for relapse. More precise prognostic and predictive tools are needed to improve treatment of such patients.

PATIENTS AND METHODS

Formalin-fixed, paraffin-embedded tumors from 239 high-risk breast cancer patients were examined for expression of human epidermal growth factor receptor 2 (HER2), epidermal growth factor receptor (EGFR), estrogen receptor, progesterone receptor, Ki-67, p16, p21, p27, and p53 by immunohistochemistry. Gene expression of EGFR, HER2, glutathione S-transferase-Pi (GSTP1), excision repair cross complementation1 (ERCC1), p21, beta-tubulin-3, multidurg resistance (MDR1), cyclooxygenase2 (COX2), and cyclin-E was measured by RT-PCR.

RESULTS

Eighty percent of patients presented with locally advanced, or > or =10 axillary nodal metastasis, and 20% with inflammatory breast cancer. The median age was 46 years (26-62 years) and the median number of involved axillary lymph nodes was 12 (0-42). At a median follow-up of 86 months, relapse-free survival (RFS) and overall survival for the entire group were 50% (95% CI 43% to 57%) and 62% (95% CI 56% to 69%). Multivariate Cox stepwise analysis resulted in a simple model for RFS consisting only of p21 expression, EGFR expression assessed by RT-PCR, and number of axillary nodal metastases.

CONCLUSION

A prognostic model on the basis of the expression of a limited number of proteins and genes may help to guide target-specific therapies in patients with high-risk breast cancer.

Surface and downhole prospecting tools for planetary exploration: tests of neutron and gamma ray probes

The ability to locate and characterize icy deposits and other hydrogenous materials on the Moon and Mars will help us understand the distribution of water and, therefore, possible habitats at Mars, and may help us locate primitive prebiotic compounds at the Moon's poles. We have developed a rover-borne neutron probe that localizes a near-surface icy deposit and provides information about its burial depth and abundance. We have also developed a borehole neutron probe to determine the stratigraphy of hydrogenous subsurface layers while operating within a drill string segment. In our field tests, we have used a neutron source to "illuminate" surrounding materials and gauge the instruments' efficacy, and we can simulate accurately the observed instrument responses using a Monte Carlo nuclear transport code (MCNPX). An active neutron source would not be needed for lunar or martian near-surface exploration: cosmic-ray interactions provide sufficient neutron flux to depths of several meters and yield better depth and abundance sensitivity than an active source. However, for deep drilling (>or=10 m depth), a source is required. We also present initial tests of a borehole gamma ray lithodensity tool and demonstrate its utility in determining soil or rock densities and composition.

Combining galiximab with the chemotherapeutic agents fludarabine or doxorubicin improves efficacy in animal models of lymphoma

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Background: Galiximab, a primatized monoclonal antibody that binds with high affinity to CD80 and mediates antibody- dependent, cell-mediated cytotoxicity in vitro, is currently under investigation for the treatment of follicular non-Hodgkin’s lymphoma (NHL). In a phase I/II monotherapy study, galiximab produced an overall response rate of 11%, and tumor reductions were observed in 46% of patients. Initial clinical trials also demonstrate that galiximab is well tolerated and suggest that combining galiximab with rituximab (anti-CD20) provides clinical benefit. These results are consistent with preclinical studies in murine lymphoma xenograft model systems, which demonstrate the superiority of combination therapy. Methods: To further define the therapeutic potential of galiximab, the Raji subcutaneous and the SKW disseminated lymphoma murine xenograft models were used to define the in vivo efficacy of galiximab alone or in combination with fludarabine or doxorubicin. Similar studies were performed with rituximab. Results: In the Raji model, both galiximab and rituximab exhibited maximal inhibition of the growth of preestablished (150-mg) tumors at a dose of 3 mg/kg/wk. Interestingly, higher doses of galiximab (but not rituximab) showed reduced inhibition. Galiximab (3 mg/kg/wk) inhibited tumor growth alone (P<0.0001 vs. control) and showed significantly enhanced activity when combined with fludarabine (50 or 100 mg/kg daily for 5 days; P<0.0002 vs. galiximab alone and P<0.003 vs. fludarabine alone). Similar results were observed with rituximab. In the SKW model, treatment with galiximab (5 mg/kg/wk for 6 doses) significantly enhanced survival compared with a control (P<0.0001) or doxorubicin (2.5 mg/kg/day for 3 doses; P<0.0001). Studies combining fludarabine or doxorubicin with both galiximab and rituximab are ongoing. Conclusions: Studies in animal models of lymphoma indicate that galiximab may provide clinical benefit when used in combination with chemotherapeutic agents such as fludarabine and doxorubicin, and provide a rationale for the investigation of these novel chemoimmunotherapy combinations in clinical trials.

No significant financial relationships to disclose.

Lumiliximab (anti-CD23 antibody) mediates apoptosis and antitumor activity in chronic lymphocytic leukemia (CLL) cells and CD23+ lymphoma cell lines

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Background: Given the success of treating CLL with antibody therapies, interest in those directed at alternative B-cell antigens remains high. Lumiliximab is a chimeric macaque and human anti-CD23 monoclonal antibody whose antigen is expressed on almost all CLL cells. Methods: We examined lumiliximab’s ability to mediate direct apoptosis, antibody-dependent cellular cytotoxicity (ADCC), and complement-dependent cytotoxicity (CDC) against primary CLL cells and CD23+ B-cell lines. Apoptosis was measured with a flow-cytometry based assay for active caspase-3. ADCC was determined by 51Cr-release assay. CDC assays were performed in the presence of 30% autologous plasma from patients and quantified by propidium iodide staining. Western blotting analysis was used to monitor protein expression before and after treatment with lumiliximab. The CD23+ human lymphoma SKW6.4 cell line was used for in vivo evaluation of lumiliximab in a disseminated human lymphoma model. Results: Lumiliximab mediates apoptosis, ADCC, and CDC in CD23+ B-cell lines. However, in primary CLL cells, the primary mechanism of cell killing appears to be mediated via apoptosis. Apoptosis induced by lumiliximab occurs mainly through the intrinsic pathway used by other CLL therapies. Lumiliximab decreased expression of Bcl-2 and XIAP and inhibited Akt activation in CLL cells. Lumiliximab when combined in vitro or in vivo with rituximab or fludarabine effectively mediates synergistic cytotoxicity against primary CLL cells and CD23+ B-cell lines. Significant antitumor activity was also observed with lumiliximab vs a control antibody in a SCID mouse model of human B-cell lymphoma (P <.01). More importantly, lumiliximab + rituximab or lumiliximab + fludarabine results in prolonged survival vs lumiliximab, rituximab, or fludarabine single-agent treatment. Conclusions: These results indicate that lumiliximab induces apoptosis by activating caspases and downregulating antiapoptotic proteins, and suggest that in combination with rituximab or chemotherapy, lumiliximab synergistically enhances antitumor activity in CLL or other B-cell malignancies in which this antigen is overexpressed.

No significant financial relationships to disclose.