TNIP1, SLC15A4, ETS1, RasGRP3 and IKZF1 are associated with clinical features of systemic lupus erythematosus in a Chinese Han population

Systemic lupus erythematosus (SLE) is an autoimmune disease with heterogeneous clinical manifestations influenced by genetic and environmental factors. Five novel susceptibility genes (TNIP1, SLC15A4, ETS1, RasGRP3 and IKZF1) for SLE have been identified in a recent genome-wide association study of a Chinese Han population. This study investigated their relationships with disease subphenotypes, including renal nephritis, photosensitivity, antinuclear antibody (ANA), age at diagnosis, malar rash, discoid rash, immunological disorder, oral ulcer, hematological disorder, neurological disorder, serositis, arthritis and vasculitis. Significant associations were found for the single nucleotide polymorphism rs10036748 of TNIP1 with photosensitivity (odds ratio (OR) = 0.87, p = 0.01) and vasculitis (OR = 1.18, p = 0.04); rs10847697 of SLC15A4 with discoid rash (OR = 1.18, p = 0.02); rs6590330 of ETS1 with SLE of age at diagnosis <20 years (OR = 1.24, p = 8.91 x 10(-5)); rs13385731 of RasGRP3 with malar rash (OR = 1.20, p = 0.01), discoid rash (OR = 0.78, p = 0.02) and ANA (OR = 0.72, p = 0.004); rs4917014 of IKZF1 with renal nephritis (OR = 1.13, p = 0.02) and malar rash (OR = 0.83, p = 0.00038), respectively. The study suggested that these susceptibility genes might not only play important roles in the development of SLE, but also contribute to the complex phenotypes of SLE.

Variants in the BRCA1/Fanconi-Anemia Repair Pathway and Taxane-Induced Neuropathy in SWOG S0221

Background: Taxane-induced peripheral neuropathy is a dose-limiting side effect that leads to suboptimal cancer treatment and diminished quality of life. The mode of taxane neurotoxicity is unclear, but may be through stabilization of microtubules and induction of spindle checkpoint, leading to cell cycle arrest at G2/M. Fanconi Anemia (FA) genes, including FANCD2, and FANCA, appear to be involved in G2/M phase checkpoint maintenance as well as spindle checkpoint in response to internal and external signals, such as taxane treatment. Thus, we hypothesized that variants in FA genes could impact severity of taxane-induced neuropathies.Methods: Using DNA extracted from blood collected from 893 breast cancer patients participating in a trial evaluating metronomic dosing of cyclophosphamide, doxorubicin and paclitaxel (S0221), we genotyped for single nucleotide polymorphisms (SNPs) that represent all of the variability across FANCA (44 SNPs) and FANCD2 (24 SNPs) in all race/ethnicity groups, as well as a panel of ancestry informative markers to control for potential population stratification, using Illumina GoldenGate platform. SNPs with minor allele frequency (MAF) less than 0.10 and those out of Hardy Weinberg Equilibrium (HWE) proportions (p&lt;0.001) were removed from analyses. Ordinal regression was used to test for allelic and haplotypic association with grade 3 or 4 toxicities relative to 0, 1, and 2 toxicities, adjusting for age, genetic admixture index and treatment arm. To adjust for multiple testing, permutation analyses were performed on both single SNP and haplotype models.Results: Eighteen SNPs in FANCD2 and 38 SNPs in FANCA passed MAF and HWE proportion requirements. For FANCD2, 4 SNPs spanning 67.5 Kb (rs7648104, rs2272125 [coding SNP], rs6786638 and rs644215), were significantly associated with taxane-induced neuropathy (p&lt;0.001) after controlling for multiple testing, with each SNP resulting in approximately a twofold increase in odds of severe taxane-induced neuropathy. Haplotype estimation showed that all 18 SNPs comprise a single haplotype. Two major (&gt;1% frequency) haplotypes were found. The frequencies of the risk haplotype in cases (patients with grade 3 or 4 neuropathy) and controls (patients with ≤ grade 2 neuropathy) were 0.25 and 0.15, respectively. Ordinal regression analyses were highly significant (p&lt;0.0005); patients with at least one copy of the risk haplotype had more than a twofold increased risk of grade 3 or 4 taxane-induced neuropathy (OR=2.2, 95% CI 1.44, 3.44). For FANCA, no SNPs or haplotypes were significantly associated with grade 3 or 4 neurotoxicity, either prior to or after correction for multiple testing.Conclusions: These results indicate that the Fanconi-Anemia pathway may be important for neurological sensitivity to taxanes, and that genotypic markers might be able to be used to identify patients at increased risk for severe taxane-induced neuropathy. Further studies will elucidate potential associations with survival outcomes.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2001.

LPS mediated injury to oligodendrocytes is mediated by the activation of nNOS: relevance to human demyelinating disease

Loss of oligodendrocytes and the destruction of myelin form the core features of inflammatory demyelinating disease. Although many of the inflammatory and cellular mediators of tissue injury are known, recent studies have suggested an important role for nitric oxide NO and other reactive nitrogen species in oligodendrocyte injury. The human transformed oligodendrocyte cell line, MO3.13 cells, express Toll like receptor genes (TLR) genes and are activated by lipopolysaccharide (LPS). We determined the activation and consequences of neuronal nitric oxide synthase (nNOS) following stimulation with LPS in the MO3.13 cell line. Our studies show that MO3.13 cells induce nNOS following stimulation with LPS. Most importantly, these studies show a susceptibility of MO3.13 cells to NO mediated cell death by the activation of nNOS but not of inducible NOS (iNOS). MO3.13 cells show increased susceptibility to peroxynitrite mediated cellular injury to mitochondrial proteins and decreased cell survival in the presence of LPS. Our studies suggest that the presence and activation of nNOS in oligodendrocytes can directly mediate oligodendrocyte (OC) injury and reduce cell viability.

Stress echocardiography: risk stratification, prognosis, patient outcomes and cost-effectiveness

The utilization of stress echocardiography has undergone considerable expansion and evolution over the past three decades. Although stress echocardiography was first conceived as a noninvasive diagnostic tool for determining the presence or absence of coronary artery disease (CAD), its prognostic value is now well established. Thus, identification of patients at risk for future cardiac events has become a primary objective in the noninvasive evaluation of patients with chest pain syndromes and among patients with known CAD. In particular, the ability of stress echocardiography to identify patients at low (<1%), intermediate (1-5%) or high (>5%) risk for future cardiac events is essential to patient management decisions. Moreover, previous studies have conclusively demonstrated the incremental prognostic value of stress echocardiography over clinical and treadmill exercise data, in predicting future cardiac events. This review addresses the current role and summarizes current literature with respect to the use of stress echocardiography in determining patient risk for cardiac events and the cost-effective integration of such information into patient management decisions.

Outcomes of conservatively managed localized prostate cancer

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Background: The natural history of screen-detected prostate cancer has not been well described. Methods: Cancer-specific and overall mortality, assessed through competing risk analyses, were determined for 14,516 men aged 65 years or older diagnosed between 1992–2002 and did not receive surgery or radiation within 6 months of cancer diagnosis. The population-based cohort was identified from US cancer registries, which had 98% completeness in case ascertainment. Results: Compared to earlier era studies, survival has improved considerably for conservatively managed patients diagnosed in the contemporary prostate specific antigen (PSA) era ( Table ). Conclusions: Men diagnosed with prostate cancer in the PSA era have survival outcomes significantly better than those in the past. Patients and healthcare providers may need to reassess some treatment options in light of these data.

[Table: see text]

No significant financial relationships to disclose.

A phase I dose-escalation study of the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of SCH 727965, a novel cyclin-dependent kinase inhibitor, administered weekly in subjects with advanced malignancies

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Background: SCH 727965 is a potent and selective inhibitor of the cyclin-dependent kinases CDK1,2,5 and 9 with IC50's of < 5nM. SCH 727965 induces apoptosis in a broad array of tumor cell lines, causes tumor growth inhibition or regression in various xenograft models, and has a greater therapeutic index than flavopiridol in an in vivo screening model. SCH 727965 was advanced into clinical trials. Methods: SCH 727965 was administered by 2-hour IV infusion on days 1, 8 and 15 of a 28-day cycle. Doses were escalated with an accelerated titration algorithm to define the maximally administered dose (MAD) and the recommended phase 2 dose (RPTD). PD assessments included an ex vivo PHA lymphocyte stimulation assay, skin biopsies for IHC measurement of retinoblastoma protein phosphorylation, and functional imaging using FDG-PET/CT scans. PK and PD data were obtained during Cycle 1. Results: 43 subjects have been treated at doses ranging from 0.33 to 14 mg/m2. The most common treatment-emergent adverse events were nausea, anemia, and fatigue. The MAD was 14 mg/m2 defined by a DLT of grade 3 hypotension in one subject and transient grade 4 hyperuricemia in another subject. The RPTD was 12 mg/m2. Grade 3 or 4 treatment related adverse events were uncommon. Grade 3 or 4 neutropenia was seen in only 3 subjects. SCH 727965 inhibition of lymphocyte proliferation was dose-dependent, indicating a PD effect, and was sustained up to 8 hours post-dose at the RPTD. Drug exposure was dose-proportional. SCH 727965 was rapidly eliminated with a terminal half-life of 1.5 to 3 hours. No objective responses by RECIST criteria have yet been observed although PET SUV signal decreases as large as >30% have been observed in some subjects. Conclusions: SCH 727965 is safe and well tolerated at the recommended phase 2 dose of 12 mg/m2. The AE profile of weekly dosing differed from that seen in an every -21 day dosing schedule, and plasma concentrations at the RPTD or lower doses were above those required for in vivo efficacy in xenograft tumor models. PD activity was verified in an ex vivo lymphocyte proliferation assay, and preliminary changes on PET/CT suggest drug related modulation of tumor metabolic activity.

[Table: see text]

Analysis of six synthetic adulterants in herbal weight-reducing dietary supplements by LC electrospray ionization-MS

A liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) method was developed for the simultaneous determination of six synthetic adulterants, namely fenfluramine, phenolphthalein, N-di-desmethyl sibutramine, N-mono-desmethyl sibutramine, sibutramine, and orlistat. The method was applied to the analysis of herbal weight-reducing dietary supplements. Chromatographic separation of the analytes on a C(8) reversed-phase column was achieved using a gradient elution of solvent A: acetonitrile and solvent B: aqueous 20 mM ammonium formate solution. Sildenafil was utilized as an internal standard for quantification. The MS detector was operated in positive electrospray ionization mode. Selected-ion monitoring (SIM) was carried out for m/z 232, 319, 252, 266, 280, 496, and 475 for fenfluramine, phenolphthalein, N-di-desmethyl sibutramine, N-mono-desmethyl sibutramine, sibutramine, orlistat, and sildenafil, respectively. The method was validated for accuracy, precision, linearity, and selectivity. The limits of detection for the six synthetic adulterants ranged from 0.0018 to 0.73 microg g(-1). The proposed method was used for a small survey of 22 dietary supplements of which eleven samples were adulterated with phenolphthalein, N-mono-desmethyl sibutramine, and sibutramine at levels from 0.212 to 96.2 mg g(-1).

Differentiation of stem cells in the dental follicle

The dental follicle (DF) differentiates into the periodontal ligament. In addition, it may be the precursor of other cells of the periodontium, including osteoblasts and cementoblasts. We hypothesized that stem cells may be present in the DF and be capable of differentiating into cells of the periodontium. Stem cells were identified in the DF of the rat first mandibular molar by Hoechst staining, alkaline phosphatase staining, and expression of side-population stem cell markers. These cells were shown to be able to differentiate into osteoblasts/cementoblasts, adipocytes, and neurons. Treating the DF cell population with doxorubicin, followed by incubation in an adipogenesis medium, suggested that the adipocytes originated from stem cells. Thus, a possibly puripotent stem cell population is present in the rat DF.

Analysis of nanoindentation response of diatom frustules

Diatom frustules have been suggested for numerous nanotechnological applications. Experimental studies using nanoindenter have shown that the hardness and the stiffness of the frustules vary with location of indentation. To gain further insight, a computational framework has been developed where the Berkovich nanoindentation experiments were simulated by a rigid-deformable contact process. Three different approaches that provide progressively increasing level of understanding of the deformation behavior of frustules were adopted. The differences in the mechanical responses of the frustule due to variation of indentation location, size of pores, and distribution of pores were analyzed. It has been found that the effective stiffness of the frustule is linearly related to the porosity level and does not depend on the frustule size or its pore architecture. It has been shown that a 3D porous shell computational model is more appropriate to simulate the experimentally obtained mechanical response of diatom frustules.

The transcriptome of the rat hypothalamic-neurohypophyseal system is highly strain-dependent

We have used microarrays to comprehensively describe the transcriptomes of the supraoptic nucleus (SON), the paraventricular nucleus (PVN) and the neurointermediate lobe of adult male Sprague-Dawley (SD) and Wistar-Kyoto (WKY) rats, as well as the PVN of Wistar rats. Comparison of these gene lists has enabled us to identify surprisingly large differences in hypothalamic-neurohypophyseal system gene expression patterns in these three strains. We have also shown that different transcript populations are enriched in the PVN and the SON of SD and WKY rats. The transcriptome differences catalogued here may be molecular substrates for the neuro-humoral phenotypic differences exhibited by different strains of rats.

Different response of articular chondrocyte subpopulations to surface motion

OBJECTIVE

To investigate the effect of surface motion on the gene expression of proteoglycan 4 (PRG4), hyaluronan synthases (HAS1, HAS2) and on the hyaluronan (HA) and proteoglycan 4 (PRG4) release of chondrocytes from different zones of bovine articular cartilage.

DESIGN

Superficial zone, deep zone, full thickness, and superficial/deep 1:1 mixed chondrocytes were seeded into 3D polyurethane scaffolds and stimulated using our bioreactor that approximates kinematics and surface motion characteristics of natural joints. One hour of surface motion superimposed on cyclic compression was applied twice a day over 3 consecutive days. Scaffolds were cut into top and bottom sections and analyzed for gene expression of PRG4, HAS1, and HAS2.

RESULTS

Depending on the cell population, the gene expression levels increased within 8 days of culture in unloaded scaffolds, with a stronger increase in the top compared to the bottom sections. Mechanical loading further enhanced the messenger RNA (mRNA) levels in all cell types, with most pronounced up-regulations observed for the PRG4 expression in deep zone and the HAS2 expression in superficial zone cells. The effect of the biochemical and biomechanical environment appeared to be additive, resulting in highest mRNA levels in the top sections of loaded constructs. Bioreactor stimulation also enhanced the HA release in all cell populations. Full thickness chondrocytes experienced the greatest effect on HAS1 mRNA expression and HA release, indicating that the interaction between cell populations may promote HA synthesis compared to subpopulations alone.

CONCLUSIONS

Reciprocating sliding can be an efficient tool for generating tissue-engineered constructs from various chondrocyte populations by providing a functional cartilage-synovial interface.

In vivo regulation of p21 by the Kruppel-like factor 6 tumor-suppressor gene in mouse liver and human hepatocellular carcinoma

Kruppel-like factor (KLF) 6 is a tumor-suppressor gene functionally inactivated by loss of heterozygosity, somatic mutation and/or alternative splicing that generates a dominant-negative splice form, KLF6-SV1. Wild-type KLF6 (wtKLF6) expression is decreased in many human malignancies, which correlates with reduced patient survival. Additionally, loss of the KLF6 locus in the absence of somatic mutation in the remaining allele occurs in a number of human cancers, raising the possibility that haploinsufficiency of the KLF6 gene alone contributes to cellular growth dysregulation and tumorigenesis. Our earlier studies identified the cyclin-dependent kinase inhibitor p21 as a transcriptional target of the KLF6 gene in cultured cells, but not in vivo. To address this issue, we have generated two genetic mouse models to define the in vivo role of KLF6 in regulating cell proliferation and p21 expression. Transgenic overexpression of KLF6 in the liver resulted in a runted phenotype with decreased body and liver size, with evidence of decreased hepatocyte proliferation, increased p21 and reduced proliferating cell nuclear antigen expression. In contrast, mice with targeted deletion of one KLF6 allele (KLF6+/-) display increased liver mass with reduced p21 expression, compared to wild type littermates. Moreover, in primary hepatocellular carcinoma samples, there is a significant correlation between wtKLF6 and p21 mRNA expression. Combined, these data suggest that haploinsufficiency of the KLF6 gene may regulate cellular proliferation in vivo through decreased transcriptional activation of the cyclin-dependent kinase inhibitor p21.

Identification of B cell epitopes at the C-terminus of latency-associated nuclear protein of the kaposi's sarcoma-associated herpesvirus

The latency-associated nuclear antigen (LANA) of Kaposi's sarcoma-associated herpesvirus (KSHV) plays a key role in the induction of cell transformation, maintenance of viral episome, and modulation of immune response in human. To identify the presence of B cell epitopes within C-terminus of LANA and to characterize the monoclonal antibodies (MAbs) against this protein, we expressed the C-terminal region at aa 794-1000 of LANA (pLANA-C) in Escherichia coli as a fusion protein. KSHV-positive human sera were able to recognize the recombinant LANA-C in the Western blot analysis and ELISA. Mapping of antigenic epitopes of pLANA-C by KSHV-positive human sera revealed two B cell antigenic epitopes located at aa 846-854 and aa 794-822. The MAb 3F11 recognized a region between at aa 840 to 846 of LANA and exhibited a strong and specific binding to both pLANA-C and native viral LANA. These findings showed that pLANA-C and MAb 3F11 could be used for the detection of KSHV antibodies in human sera and for the advanced study of biological functions of LANA.

Catalytic oxidation of benzene using DBD corona discharges

Plasma oxidation of benzene (C(6)H(6)) in oxygen and nitrogen was investigated using a dielectric barrier discharge (DBD) reactor with or without MnO2 or TiO2 at atmospheric pressure and without external heating except plasma heating. An alternative current power supply was used to generate corona discharges for the plasma oxidation. The energy density was controlled under 200 J/L to keep an increase in gas temperature less than 167 K. C(6)H(6) was oxidized to carbon monoxide (CO) and dioxide (CO(2)). Typically, the energy efficiency at an energy density of 92J/L was about 0.052, 0.039, and 0.024 mol/kWh with MnO2, TiO2, and without MnO2 and TiO2, respectively. Benzene oxidation mechanism was mentioned. A comparison on energy efficiency as a function of initial concentration of hydrocarbons, inorganic sulphur compounds, and chloro (fluoro and bromo) carbons was given.

Pre-treatment PSA doubling time (PSADT) predicts biochemical response to chemotherapy in patients with androgen sensitive PSA progression after local therapy

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Background: As phase III studies are developed in patients with androgen sensitive (AS) PSA progression after local therapy, efforts to stratify patients based on likelihood of benefit is critical. In an effort to define a pretreatment PSADT cutoff that predicts chemotherapy response in AS patients for use in hypothesis testing in phase III studies, we assessed patients with pretreatment PSA data in two of our prior published phase II studies of docetaxel (D) or mitoxantrone (M) chemotherapy in patients with AS PSA progression without metastasis. Methods: A retrospective analysis of PSADT was performed on 36 pts with AS PSA progression following local therapy without metastasis with available pretreatment PSA values (23 pts with D and 13 pts with M). PSADT was calculated as [LN(2)]/b, where b is the slope of the regression of LN(PSA) vs time. A t-test was used to compare the PSADT of responders vs non-responders; ANOVA was used for the combined data. A logistic regression analysis with ROC curves was used to evaluate the value of PSADT in discriminating response. Results: Mean PSADT of patients with ≥50% decrease in PSA with therapy was 204 vs. 99 days (P = 0.02). For D only, mean PSADT of pts with any PSA decrease (mean 52%) vs. increase was 211 vs. 115 days (P = 0.04). The mean PSADT of pts with ≥50% PSA decrease only on D was 203 vs. 174 days (P = 0.31). Overall, logistic regression analysis showed that PSADT is a good test to discriminate which pts will have some decrease in PSA while on treatment (P = 0.03). ROC curves (AUC = 0.807) for pts with a decline in PSA on treatment showed that the best balance of sensitivity and specificity was for a PSA DT cutoff of 70 days (sens = 70.0%, spec = 71.4%). Sensitivity was highest at a DT of 50 days (85%), and specificity at 180 days (93%). Conclusions: This study suggests that pretreatment PSADT may be a useful predictor of response to therapy in patients with AS PSA progression after local therapy, but will require larger confirmatory studies. A PSADT cutoff of 70 days can be considered to stratify patients in future trials in this patient population.

No significant financial relationships to disclose.

Utility of the SEER-Medicare data to identify medical androgen deprivation therapy

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Background: Researchers are increasingly using SEER-Medicare data to measure the use of various cancer therapies. However, the validity and completeness of Medicare data as a source of information for identifying medical androgen deprivation has not been established. In this study, we compared the classification of ADT use based on SEER-Medicare linked data and medical record review. Methods: Among patients who were included in the Prostate Cancer Outcomes Study (PCOS) aged 65 or older and have Medicare part A and B coverage as their primary health insurance, their use of medical androgen deprivation therapy (ADT) identified from the SEER-Medicare data was compared with the results of medical record review. The linkage of the datasets was accomplished by using encrypted IDs. Two algorithms were evaluated. Algorithm A defines ADT use liberally, if at least one of the following HCPCS codes is present: J1950, J9202, J9217, J9218, or J9219. Algorithm B, developed by the authors to identify consistent androgen deprivation, defines ADT only if there is evidence of treatment lasting for 3 months or longer, indicated by either the 12-month treatment J9219 or at least 3 months of treatment with J9202 or J9217. Results: For the 673 patients eligible for this validation study, algorithm A has a sensitivity of 92.5% and a specificity of 85.2% in identifying medical ADT compared to medical record review (see table ), while algorithm B has a sensitivity of 81.8% and a specificity of 88.9% ( Table 1 ). When the study was further restricted to patients with Medicare insurance only (N=142), both algorithms improved: 96.2% sensitivity and 85.6% specificity for algorithm A, and 88.5% sensitivity and 91.1% specificity for algorithm B. Conclusions: Both algorithms have reasonable sensitivity and specificity. Medicare claims can be used to track ADT use for the treatment of prostate cancer in the Medicare population.

[Table: see text]

No significant financial relationships to disclose.