[Chemical constituents from Hedyotis diffusa]

OBJECTIVE

To investigate the chemical constituents from Hedyotis diffusa.

METHOD

The compounds were isolated and purified by various chromatographic techniques and identified by their physicochemical properties and spectral data.

RESULT

Eight compounds had been reported in last paper, and this time eight more compounds were isolated and identified as 6-hydroxystigmasta-4,22-dien-3-one (1), 3-hydroxystigmasta-4,22-dien-7-one (2), 2-hydroxy-3-methylanthraquinone (3), 2,6-dihydroxy-3-methyl-4-methoxyanthraquinone (4), iso-scutellarein (5), isoetin (6), aesculetin (7), gypsogenic acid (8).

CONCLUSION

Compounds 1-3, 5-8 were obtained from the genus Hedyotis for the first time.

Association of early growth response-1 gene polymorphisms with total IgE and atopy in asthmatic children

Early growth response-1 (Egr-1) is expressed in human airways and found to modulate tumor necrosis factor, immunoglobulin E (IgE), airway responsiveness, and interleukin-13-induced inflammation in mice. We investigated the effects of Chinese-tagging single nucleotide polymorphisms (SNPs) of Egr-1 on asthma traits in 298 Chinese asthmatic children and 175 controls, and a replication community cohort of 191 controls. Tag SNP (-4071 A-->G) and three additional SNPs (-1427 C-->T, -151 C-->T and IVS1 -42 C-->T) were genotyped by restriction fragment length polymorphism (RFLP). Significant associations were found between plasma total IgE concentration and -4071 A-->G (p = 0.008) and IVS1 -42 C-->T (p = 0.027) in asthmatic patients. After Bonferroni correction, only -4071 A-->G showed significant association. Multivariate regression analysis confirmed this significant association with a standardized coefficient beta of 0.156 (95% CI: 0.046-0.317; p = 0.009) in asthmatics among the three SNPs with age and gender-adjusted. In -4071 A-->G, IgE(log) was significantly higher in patients with the GG genotype than the AA genotype (p = 0.009). In addition, -4071 A-->G was significantly associated with atopy (p = 0.016) and high total IgE concentration (p = 0.030) among asthmatics. Patients with the G allele had a 3.5-fold risk of having atopy and a 2.0-fold risk of having high total IgE concentration than those homozygous for the A allele. This is the first report to show significant association of Egr-1 polymorphisms with plasma total IgE and atopy in asthmatics. It may help to explore the pharmacogenetics of Egr-1 inhibitors.

Quantitative measurements of HER2 expression and HER2 homodimer using a novel proximity based assay: comparison with HER2 status by immunohistochemistry and chromogenic in situ hybridization in the FinHer study

Abstract #2071

Background: The accuracy and reliability of current methods, immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), to assess HER2 status has recently been a subject of debate. The best method to assess HER2 status remains controversial. We developed a novel assay (HERmark, Monogram Biosciences) that provides precise quantification of HER2 expression (H2T) and HER2 homodimer (H2D) in formalin-fixed paraffin-embedded (FFPE) tissues. We compared H2T and H2D to local IHC, central chromogenic in situ hybridization (CISH) and central IHC retesting of breast cancers from the FinHer study.
 Methods: H2T and H2D were detected through light-dependent release of fluorescent tags (VeraTag reporters) conjugated to a HER2 antibody, requiring proximity to a second HER2 “scissors” antibody. The VeraTag signal was quantified by capillary electrophoresis and normalized to tumor area. Assay comparisons correlated H2T and H2D with HER2 testing by local IHC and central CISH from FinHer (Joensuu et al, N Engl J Med 2006;354), as well as central HER2 status reassessment by combination of externally performed central IHC retesting (PhenoPath labs, Seattle, WA) and central CISH (FinHer) according to ASCO/CAP guideline for HER2 testing in breast cancer (Wolff et al, Arch Pathol Lab Med 2007;131).
 Results: H2T and H2D in 899 evaluable FinHer samples described a continuum over a wide dynamic range (∼ 3 logs), in contrast with conventional IHC categories (0-3+). The correlation between H2T and IHC categories was significant (P < .0001). Overlap of H2T among the IHC categories was observed. H2D showed a similar correlation with IHC and a general correlation with H2T (P < .0001). A H2T cutoff value, based on its ability to distinguish high and low responders in a cohort of metastatic breast cancer patients treated with trastuzumab-based regimens (log10 H2T= 1.14, Leitzel et al, 2008 ASCO, abstract 1002), was used to define HERmark negative (-) and positive (+), which were then compared with IHC and CISH results. The concordances between HERmark (-) and local IHC (-), central CISH (-), and central HER2 reassessment (-) were 89%, 84%, and 91%, respectively. The concordances between HERmark (+) and local IHC (+), central CISH (+), and central HER2 reassessment (+) were 71%, 89%, and 92%, respectively. The HERmark test showed greater overall concordance with central HER2 reassessment (91%) than with local IHC (84%) and central CISH (87%)
 Conclusions: HERmark reliably measures H2T and H2D in FFPE tissues. H2T showed excellent concordance with central HER2 status according to ASCO/CAP guideline for HER2 testing. The precise quantification of H2T and H2D may provide novel, quantifiable, predictive tests for targeted HER2 therapy.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2071.

Quantitative HER2 homodimer levels correlate with time to first recurrence in HER2-positive breast cancer patients who did not receive trastuzumab in the adjuvant setting

Abstract #1074

BACKGROUND: HER2-positive breast cancer patients are currently treated with trastuzumab in the adjuvant setting, but prior to 2005 these patients were not routinely offered trastuzumab, creating an opportunity to examine the relationship between HER2 expression and disease progression. The VeraTag technology is a proximity-based assay system that permits quantitative measurements of total HER2 protein expression (H2T) as well as HER2 homodimers (H2D) in formalin-fixed paraffin-embedded (FFPE) tissues. We measured H2T and H2D in a cohort of patients who were HER2-positive but did not receive trastuzumab in the adjuvant setting, and correlated those measurements with time to first recurrence of disease.
 METHODS: Patients were selected for study because they were treated with a trastuzumab-containing regimen for HER2+ metastatic breast cancer. HER2-positivity was defined as IHC (Herceptest) 3+ or 2+, FISH+ (Vysis). 96 HER2+ patients who had been treated (but not with trastuzumab) in the adjuvant setting were identified. The VeraTag assay was used to quantitate H2T and H2D. Kaplan-Meier and Cox proportional hazards analyses were employed.
 RESULTS: The distribution of H2T ranged over approximately 135-fold, and H2D varied over approximately 100-fold. In univariate Cox proportional hazards regression analysis, H2T trended toward significance (HR=1.44, p= 0.088) while both H2D (HR=1.39, p=0.022) and the ratio H2D/H2T (HR=2.01, p=0.03) were significantly correlated with time to first recurrence. Kaplan-Meier analysis of the H2T distribution divided into tertiles showed no significant difference in time to first recurrence among the tertiles (HR=0.7, p=0.16 for low vs. high comparison) and no trend was observed (Log Rank test for trend p=0.2). However, the same analyses performed using H2D (HR=0.59, p=0.03) or H2D/H2T (HR=0.56, p=0.01) demonstrated significantly longer time to first recurrence for the lowest tertile compared with the highest tertile respectively. A trend was observed in both cases (H2D: Log Rank p=0.048; H2D/H2T: Log Rank p=0.026)
 CONCLUSION: In a population of HER2+ patients who did not receive trastuzumab in the adjuvant setting, and who subsequently developed metastatic disease, higher levels of HER2 homodimers and the ratio of homodimers to HER2 total expression correlated with time to first recurrence while total HER2 expression levels did not. These data suggest that measures of the activated forms of HER2 (dimers) may be better predictors of disease progression than simple quantitation of HER2 alone.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1074.

Characterization of a functional polymorphism in the 3' UTR of SLC6A4 and its association with drinking intensity

BACKGROUND

The propensity for severe drinking is hypothesized to be regulated by differential expression of serotonin transporter gene (SLC6A4) in the human brain. The SLC6A4 promoter region 5-HTTLPR has been examined previously as a candidate polymorphic variant associated with severe drinking. In this study, we investigated whether other SLC6A4 single nucleotide polymorphisms (SNPs) are associated with drinking intensity among treatment-seeking alcoholics and whether these polymorphic variants result in differential SLC6A4 expression levels.

METHODS

We analyzed associations of drinking intensity in 275 (78.5% male) treatment-seeking alcoholics of Caucasian and Hispanic origin, with 6 SLC6A4 polymorphisms. Next, to examine the functionality of the SNP that showed a significant association with drinking intensity, we transfected the 2 alleles of rs1042173 into HeLa cell cultures and measured serotonin transporter mRNA and protein expression levels by using qRT-PCR and western blotting techniques.

RESULTS

One of the 6 polymorphisms we examined, rs1042173 in the 3' untranslated region (3'-UTR) of SLC6A4, showed a significant association with drinking intensity. The G allele carriers for rs1042173 were associated with significantly lower drinking intensity (p = 0.0034) compared to T-allele homozygotes. In HeLa cell cultures, the cells transfected with G allele showed a significantly higher mRNA and protein levels than the T allele-transfected cells.

CONCLUSION

These findings suggest that the allelic variations of rs1042173 affect drinking intensity in alcoholics possibly by altering serotonin transporter expression levels. This provides additional support to the hypothesis that SLC6A4 polymorphisms play an important role in regulating propensity for severe drinking.

A functional polymorphism, rs6280, in DRD3 is significantly associated with nicotine dependence in European-American smokers

Nicotine enhances reward functions in the mesocorticolimbic dopamine system in general and the nucleus accumbens in particular. The genes encoding dopamine receptors are thus plausible candidates for involvement in nicotine dependence (ND). We investigated 13 single nucleotide polymorphisms (SNPs) spanning a region of the dopamine D(3) receptor gene (DRD3) to determine whether DRD3 is associated with ND. We studied a set of 2,037 subjects in 602 nuclear families representing two distinct American populations using three ND measures, namely, smoking quantity (SQ), the Heaviness of Smoking Index (HSI), and the Fagerström Test for ND (FTND). In the family based association study, we found that SNP rs6280 showed a strong association with ND in European-Americans (EAs) and the pooled sample, whereas SNPs rs1486012 and rs963468 had weak associations with ND in African-Americans (AAs) and the pooled sample. Further haplotype analysis with all contiguous 3-SNP groups revealed relatively weak evidence for association of DRD3 with ND in the EA and pooled samples. The results indicate that DRD3 is significantly associated with ND in EAs, and that rs6280, a functional polymorphism causing an amino acid change of serine to glycine (Ser9Gly) in the N-terminal extracellular domain of the D(3) receptor, likely is causative of the association between DRD3 and ND.

Delay to angiography and outcomes following presentation with high-risk, non-ST-elevation acute coronary syndromes: results from the Global Registry of Acute Coronary Events

OBJECTIVE

To test if delay-to-angiography (>72 hours from admission) in patients presenting with high-risk non-ST-elevation acute coronary syndromes (NSTE-ACS) is associated with adverse outcomes.

DESIGN

GRACE (Global Registry of Acute Coronary Events) is a multinational registry of patients admitted with NSTE-ACS.

SETTING

14 countries with varying healthcare systems.

PATIENTS

23 396 high-risk NSTE-ACS patients with complete initial data collection entered into GRACE between 1999 and 2006 were analysed.

INTERVENTIONS

Data were analysed according to delay-to-angiography and subsequent in-hospital or post-discharge adverse outcomes.

MAIN OUTCOME MEASURES

Outcomes recorded included death, myocardial infarction, recurrent ischaemia, stroke, new heart failure and composite major adverse cardiovascular event (MACE) comprising death, cerebrovascular accident and myocardial infarction. Revascularisation procedures were recorded.

RESULTS

10 089 (43.1%) had no in-hospital angiography. Median delay-to-angiography was 46 hours; 3680 (34%) patients waited >72 hours. 9.3% waited >7 days before angiography. Patients waiting longest were more often older, diabetic, women and had a history of heart failure, previous myocardial infarction or hypertension. Recurrent in-hospital ischaemia (33% vs 22%), reinfarction (8.4% vs 5.0%) and heart failure (14% vs 9.1%) were more common with delayed angiography. Delayed angiography was associated with better outcomes than no angiography (MACE 18.9% vs 22.2%, p = 0.015). MACE rates within six months of admission were higher with longer delay-to-angiography and highest of all with no angiography.

CONCLUSIONS

High-risk NSTE-ACS is suboptimally managed with 43% not undergoing angiography. One-third of those undergoing angiography are delayed >72 hours. Longer delays were more likely with higher risk, sicker patients. These delays were associated with adverse outcomes at six months. Very long delay was associated with lower MACE, but not mortality, compared to conservative management.

Polymorphisms in the C-type lectin genes cluster in chromosome 19 and predisposition to severe acute respiratory syndrome coronavirus (SARS-CoV) infection

BACKGROUND

Polymorphisms of CLEC4M have been associated with predisposition for infection by the severe acute respiratory syndrome coronavirus (SARS-CoV). DC-SIGNR, a C-type lectin encoded by CLEC4M, is a receptor for the virus. A variable number tandem repeat (VNTR) polymorphism in its neck region was recently associated with susceptibility to SARS infection. However, this association was controversial and was not supported by subsequent studies. Two explanations may account for this discrepancy: (1) there may be an unknown predisposition polymorphism located in the proximity which is linked to the VNTR; or (2) it was a spurious association due to unrecognised population structure in the VNTR.

METHODS

We performed a comprehensively genetic association study on this C-type lectin gene cluster (FCER2, CLEC4G, CD209, and CLEC4M) at 19p13.3 by a tagging single nucleotide polymorphisms (SNPs) approach.

RESULTS

23 tagSNPs were genotyped in 181 SARS patients and 172 population controls. No significant association with disease predisposition was detected. Genetic variations in this cluster also did not predict disease prognosis. However, we detected a population stratification of the VNTR alleles in a sample of 1145 Han Chinese collected from different parts of China.

CONCLUSION

The results indicated that the genetic predisposition allele was not found in this lectin gene cluster and population stratification might cause the previous positive association.

Study of gene-gene interactions for endophenotypic quantitative traits in Chinese asthmatic children

BACKGROUND

Asthma is a complex disease resulting from interactions between multiple genes and environmental factors. Study of gene-gene interactions could provide insight into the pathophysiology of asthma.

METHODS

We investigated the interactions among 18 single-nucleotide polymorphisms in eight candidate genes for plasma total immunoglobulin E (IgE) concentration and peripheral blood (PB) eosinophil count in 298 Chinese asthmatic children and 175 controls. Generalized multifactor dimensionality reduction and generalized linear model were used to analyze gene-gene interactions for the quantitative traits.

RESULTS

A significant interaction was found between R130Q in IL13 and I50V in IL4RA for plasma total IgE concentration, with a cross-validation (CV) consistency of nine of 10 and a prediction error of 41.1% (P = 0.013). Plasma total IgE concentration was significantly higher in the high-risk than the low-risk groups (P < 0.0001). For PB eosinophil count, significant interaction was found between C-431T in TARC and RsaI_in2 in FCERIB, with a CV consistency of nine of 10 and a prediction error of 40.2% (P = 0.009). PB eosinophil count was significantly higher in the high-risk group than the low-risk groups (P < 0.0001). Generalized linear model also revealed significant gene-gene interaction for the above two endophenotypes with P = 0.013 for plasma total IgE concentration and P = 0.029 for PB eosinophil count respectively.

CONCLUSIONS

Our data suggest significant interactions between IL13 and IL4RA for plasma total IgE concentration, and this is the first report to show significant interaction between TARC and FCERIB for PB eosinophil count in Chinese asthmatic children.

Suppression of p38 mitogen-activated protein kinase inhibits hepatitis B virus replication in human hepatoma cell: the antiviral role of nitric oxide

The role of the p38 mitogen-activated protein kinase (MAPK) pathway in hepatitis B virus (HBV) replication was investigated in this study. After transient transfection with HBV plasmid, p38 MAPK, but not JNK or ERK1/2, was significantly phosphorylated in human hepatoma cell Huh7. Interestingly, HBV proteins and RNA synthesis were significantly inhibited by a specific inhibitor of p38 MAPK, SB203580, in a dose-dependent manner. Intracellular core-associated DNA, extracellular virion-associated DNA and covalently closed circular DNA were also significantly inhibited by SB203580. Further results showed the antiviral role of nitric oxide (NO) on the suppression of HBV replication and downregulation of p38 MAPK phosphorylation. In conclusion, these results suggested that suppression of phosphorylation of p38 MAPK by inhibitor or NO could inhibit intracellular HBV replication.

A proline-to-histidine mutation in POU1F1 is associated with production traits in dairy cattle

POU class 1 homeobox 1 (POU1F1) is a member of the tissue-specific POU-containing transcription factor family. The expression of POU1F1 in mammalian pituitary gland controls the transcription of the genes encoding growth hormone, prolactin (PRL) and the subunits of thyroid-stimulating hormone. In addition, some genes in the JAK/STAT signalling pathway downstream of POU1F1 have been shown to be associated with different production traits in dairy cattle. To investigate whether the POU1F1 gene is associated with economically important traits in dairy cattle, a pooled DNA sequencing approach was used to identify single nucleotide polymorphisms (SNPs) in the gene. An SNP in exon 3 of POU1F1 that changes a proline to a histidine was identified. A total of 2141 individuals from two North American Holstein cattle resource populations were genotyped for this SNP using a modified PCR-RFLP method. Statistical analyses revealed significant association of POU1F1 variants with milk yield and productive life, which makes POU1F1 a possible candidate for marker-assisted selection in dairy cattle breeding programmes.

Two new cytotoxic pregnane glycosides from Cynanchum auriculatum

Two new pregnane glycosides, kidjoranin 3- O- alpha-diginopyranosyl-(1-->4)- beta-cymaropyranoside (1) and kidjoranin 3-O-beta-digitoxopyranoside (2), together with one known compound caudatin 3 -O-beta-cymaropyranoside (3), were isolated from the roots of Cynanchum auriculatum. Their structures were established on the basis of NMR analyses. Compounds 1 - 3 were tested for their in vitro inhibitory activity against the growth of human tumor cell lines SMMC-7721, HeLa and MCF7; all of them displayed marked cytotoxic activities against cells SMMC-7721 and HeLa with IC (50) values ranging from 8.6 microM to 58.5 microM, yet no activity against the cell line MCF7 was detected.

VEGF-siRNA silencing induces apoptosis, inhibits proliferation and suppresses vasculogenic mimicry in osteosarcoma in vitro

AIM

To inhibit the gene expression of vascular endothelial growth factor (VEGF) with the RNA interference (RNAi) technique and explore its influence on the apoptosis, proliferation, vasculogenic mimicry of osteosarcoma in vitro.

METHODS

PSilencer-VEGF plasmid transfected into osteosarcoma cell line of MG63 was recombinated by gene cloning, and VEGF expression was examined by Western blotting after transfection. The biological features of transfected MG63 including proliferation, apoptosis and vasculogenic mimicry, were assessed by MTT assay, flowcytometer, annexin V-FITC/PI, light microscopy and HE staining.

RESULTS

The sequence of pSilencer-VEGF plasmid was confirmed by DNA sequencing. Sequence-specific siRNA targeting VEGF significantly decreases its expression in MG63 cells. Cell growth was inhibited and early apoptosis was induced compared with non-siRNA tansfected cells. Decreased VEGF expression was associated with reduced vasculogenic mimicry of MG63 cells.

CONCLUSIONS

VEGF gene might be closely related to the apoptosis and proliferation of osteosarcoma cells, and appears to be crucial for formation of vasculogenic mimicry in osteosarcoma. Inhibition of VEGF expression by sequence-specific siRNA may become a novel approach for the treatment of VEGF-enriched neoplasma such as osteosarcoma.

Significant association of the neurexin-1 gene (NRXN1) with nicotine dependence in European- and African-American smokers

The neurexin-1 gene (NRXN1) has been shown to play a fundamental role in synaptogenesis and synaptic maintenance, as well as Ca(2+) channel and NMDA receptor recruitment. A recent study reported that NRXN1 is associated with nicotine dependence (ND); this, together with the intriguing physiological functions of the gene, motivated us to investigate the involvement of NRXN1 with ND in independent samples. In this study, we analyzed 21 single nucleotide polymorphisms (SNPs) within NRXN1 for association with ND, which was assessed by smoking quantity (SQ), the heaviness of smoking index (HSI) and the Fagerström test for ND (FTND). Individual SNP and haplotype association tests were carried out in a sample consisting of 2037 individuals from 602 nuclear families of African-American (AA) or European-American (EA) origin. Individual SNP analysis revealed significant associations of rs2193225 with SQ, HSI and FTND (P = 0.00014-0.0010) in the EA sample and with SQ (P = 0.0019) in the pooled sample under the dominant model and rs6721498 with SQ, HSI and FTND in the AA (P = 0.000090-0.0000086) and pooled (P = 0.0010-0.00099) samples under the additive model, following correction for multiple testing. Haplotype analysis revealed six major haplotypes in the AA sample (minimum P-value = 0.000079), one major haplotype in the EA sample (P = 0.0062) and five major haplotypes in the pooled sample (minimum P-value = 0.00083), which showed significant association with all three ND measures; all of these contained one specific allele from one of the two aforementioned SNPs. Based on our findings that NRXN1 has significant association with ND in two independent samples, recent findings that NRXN1 plays an important role in synaptic development, and the previous report of association, we conclude that this gene represents a strong candidate for involvement in the etiology of ND.