Targeting Src/Stat3 pathway in malignant melanoma

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Background: The Src/Stat 3 pathway has been implicated in the pathogenesis of several malignancies including melanoma. In the current study we evaluated the prevalence of Src and Stat3 activation in human melanoma and the effect of Src inhibitors alone or in combination with chemotherapeutic agents on melanoma cell lines. Methods: Activation of Src was measured by staining for Src-phosphotyrosine 416 (P-Src) and Stat3 by phosphotyrosine 705 Stat3 (P-Stat3). Immunohistochemistry was performed with anti-pStat3-Y705 and anti-pSrc-Y416 antibodies (Cell Signaling, Beverly, MA) on 3 melanoma subtypes. Staining of tumor cells for P-Stat3 was scored by percentage of stained cells as follows: 0 (no staining), 1 (1–25%), 2 (26–50%), 3 (>50%), and intensity 0–3 (0: absent, 1: low, 2: moderate, and 3: high). The sum of these was the composite P-Stat3 score: 0 (0), 1 (1–2), 2 (3–4), and 3 (5–6). P-Src staining was scored by intensity. Melanoma cell lines, A-375, SK-Mel-5 and SK-Mel-28 were exposed to Src inhibitors, SKI-606, PD 180970 and BMS 354825 alone or in combination with standard chemotherapy agents and IC-50 was determined by MTT assay at 24 and 72 hours. Results: 35 biopsies were stained. Median age was 66 years (range 23–90); 60% were women. 48% of all melanoma stained express P-Src; all samples express pStat3. We found a positive correlation between P-Src and P-Stat3 (Spearman coefficient=0.346, p=0.042). 46% stained only for pStat3 and 6% did not stain for either P-Src or P-Stat3. Most positively stained biopsies stained weakly for P-Src and moderately or strongly for pStat3. Src inhibitors inhibited the proliferation of melanoma cell lines; furthermore Src inhibitor treatment synergized with platinum and topoisomerase I inhibitors but not temozolomide. Conclusions: 1) Immunohistochemistry shows variable expression of P-Src and P-Stat3 in human melanoma 2) All tumors staining for P-Src also stain for P-Stat3 and the strength of staining is significantly related. 3) This data may be useful in planning future clinical trials with Src inhibitors in melanoma.

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Circulating endothelial microparticles in acute ischemic stroke: a link to severity, lesion volume and outcome

BACKGROUND

Endothelial membrane microparticles (EMP) in plasma are elevated in several vascular diseases.

OBJECTIVES

To test the hypothesis that EMP would be increased in patients with acute ischemic stroke and would correlate with stroke severity, brain lesion volume and outcome.

PATIENTS AND METHODS

Forty-one patients were studied and divided into two groups based on the National Institutes of Health Stroke Scale (NIHSS) score: 20 patients with mild stroke (NIHSS score < 5) and 21 patients with moderate-severe stroke (NIHSS score > or = 5). Lesion volume was measured using diffusion-weighted magnetic resonance imaging and discharge outcome was based on the discharge Barthel and Rankin scores. Twenty-three age-matched control subjects were also studied. Using flow cytometry, endoglin-positive EMP: CD105+ CD41a-CD45- (E(+)EMP), specific endothelial EMP expressing VE-cadherin and endoglin: CD105+CD144+ (C(+)EMP), EMP expressing phosphatidylserine: CD105+PS+ CD41a- (PS(+)EMP) and EMP expressing ICAM-1: CD105+CD54+ CD45- (I(+)EMP) were analyzed.

RESULTS

Significantly higher PS(+)EMP counts were observed in the group of acute ischemic stroke patients [median 59 (25th-75th percentile: 28-86) MP microL(-1)] relative to the controls [28 (14-36) MP microL(-1)] (P = 0.002). All four EMP phenotypes studied were elevated in the subgroup of moderate-severe stroke patients relative to the controls (all P < 0.05). In the patients with acute ischemic stroke three EMP phenotypes (E(+)EMP, PS(+)EMP and I(+)EMP) correlated significantly with brain lesion volume, with I(+)EMP (P = 0.002) showing the strongest correlation. Admission counts of C(+)EMP (P = 0.0003) and E(+)EMP (P = 0.003) correlated significantly with discharge clinical outcome.

CONCLUSIONS

Certain circulating EMP phenotypes may be associated with severity, lesion volume and outcome of acute ischemic stroke. EMP analysis shows promising contribution to understanding stroke pathophysiology.

Methylation of the insulin-like growth factor binding protein-3 gene and prognosis of epithelial ovarian cancer

Insulin-like growth factor binding protein-3 (IGFBP-3) is a member of the IGFBP family, which regulates the mitogenic and antiapoptotic effects of insulin-like growth factors. Hypermethylation of the IGFBP-3 promoter has been found to suppress its expression. To evaluate the role of IGFBP-3 in ovarian cancer progression, we examined the survival of 235 consecutively selected epithelial ovarian cancer patients in association with IGFBP-3 promoter methylation and IGFBP-3 expression in tumor tissue. IGFBP-3 promoter methylation was analyzed using methylation-specific polymerase chain reaction. Cytosol protein was extracted and measured using a bicinchoninic acid assay; IGFBP-3 was measured by enzyme linked immunosorbent assay. Promoter methylation of the IGFBP-3 gene was detected in 44% (104/235) of patients. IGFBP-3 promoter methylation was associated with disease progression and death after adjusting for clinical and pathologic variables. The association was more evident in patients with early-stage disease: RR = 2.87 (95% CI: 0.78-10.63) for disease progression and RR = 3.94 (95% CI: 0.91-15.78) for death. Tissue levels of IGFBP-3 did not differ by methylation status but were inversely associated with disease stage and residual tumor size. These results suggest that IGFBP-3 promoter methylation may be a useful prognostic marker for disease progression and death in early-stage ovarian cancer.

A rapid HPLC–ESI-MS/MS for qualitative and quantitative analysis of saponins in “XUESETONG” injection

'XUESETONG' injection, one of the most widely used proprietary medicines in traditional Chinese medicine, consists of total saponins made from Panax notoginseng, which is a highly valued and important Chinese medicinal herb. It is used to treat cardiovascular diseases. In order to control the quality of XUESETONG injection, a rapid HPLC-ESI-MS/MS method was developed for qualitative and quantitative determination of the saponins. The analyses were performed on SB-C18 column using gradient elution in 25 min. Full scan and time programmed selected reaction monitoring (SRM) were used for qualitative and quantitative analysis of saponins, respectively. Twenty-seven saponins were identified and nine of them including notoginsenoside R1, ginsenoside Rb1, Rb2, Rb3, Rc, Rd, Re, Rf and Rg1 were quantified. Ten XUESETONG injections were analyzed and compared. The results showed that there is a great variation among different samples. In conclusion, the developed method is rapid, accurate and sensitive for qualitative and quantitative analysis of saponins in XUESETONG injection. Moreover, it also can be used for the quality control of P. notoginseng raw material and its preparations.

Antimicrobial activity of essential oils and structurally related synthetic food additives towards selected pathogenic and beneficial gut bacteria

AIMS

To assess the potential of essential oils and structurally related synthetic food additives in reducing bacterial pathogens in swine intestinal tract.

METHODS AND RESULTS

The antimicrobial activity of essential oils/compounds was measured by determining the inhibition of bacterial growth. Among 66 essential oils/compounds that exhibited > or =80% inhibition towards Salmonellatyphimurium DT104 and Escherichia coli O157:H7, nine were further studied. Most of the oils/compounds demonstrated high efficacy against S. typhimurium DT104, E. coli O157:H7, and E. coli with K88 pili with little inhibition towards lactobacilli and bifidobacteria. They were also tolerant to the low pH. When mixed with pig cecal digesta, these oils/compounds retained their efficacy against E. coli O157:H7. In addition, they significantly inhibited E. coli and coliform bacteria in the digesta, but had little effect on the total number of lactobacilli and anaerobic bacteria.

CONCLUSIONS

Some essential oils/compounds demonstrated good potential, including efficacy, tolerance to low pH, and selectivity towards bacterial pathogens, in reducing human and animal bacterial pathogens in swine intestinal tract.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study has identified candidates of essential oils/compounds for in vivo studies to develop antibiotic substitutes for the reduction of human and animal bacterial pathogens in swine intestinal tract.

Creatine in Huntington disease is safe, tolerable, bioavailable in brain and reduces serum 8OH2'dG

In a randomized, double-blind, placebo-controlled study in 64 subjects with Huntington disease (HD), 8 g/day of creatine administered for 16 weeks was well tolerated and safe. Serum and brain creatine concentrations increased in the creatine-treated group and returned to baseline after washout. Serum 8-hydroxy-2'-deoxyguanosine (8OH2'dG) levels, an indicator of oxidative injury to DNA, were markedly elevated in HD and reduced by creatine treatment.

The spindle checkpoint and chromosomal stability

Normal human somatic cells contain 46 chromosomes (22 pairs of autosomes and two sex chromosomes). Chromosome missegregation leads to abnormal numbers of chromosomes or aneuploidy. This form of genetic instability alters the dosages of large subsets of genes, which can result in severe disease phenotypes. Most human cancer cells are aneuploid. It is generally believed that aneuploidy contributes to cancer formation. The spindle checkpoint is a cell-cycle surveillance mechanism that ensures the fidelity of chromosome segregation during mitosis and meiosis. In this article, we review our current understanding of the molecular basis of the spindle checkpoint and the recent evidence that links the malfunction of this checkpoint to aneuploidy and tumorigenesis.

Recent insights into the Smith-Lemli-Opitz syndrome

Recent insights into the Smith-Lemli-Opitz syndrome. The Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive multiple congenital anomaly/mental retardation disorder caused by an inborn error of post-squalene cholesterol biosynthesis. Deficient cholesterol synthesis in SLOS is caused by inherited mutations of 3beta-hydroxysterol-Delta7 reductase gene (DHCR7). DHCR7 deficiency impairs both cholesterol and desmosterol production, resulting in elevated 7DHC/8DHC levels, typically decreased cholesterol levels and, importantly, developmental dysmorphology. The discovery of SLOS has led to new questions regarding the role of the cholesterol biosynthesis pathway in human development. To date, a total of 121 different mutations have been identified in over 250 patients with SLOS who represent a continuum of clinical severity. Two genetic mouse models have been generated which recapitulate some of the developmental abnormalities of SLOS and have been useful in elucidating the pathogenesis. This mini review summarizes the recent insights into SLOS genetics, pathophysiology and potential therapeutic approaches for the treatment of SLOS.

Tolerance of high-dose (3,000 mg/day) coenzyme Q10 in ALS

An open-label dose-escalation trial was performed to assess the safety and tolerability of high doses of coenzyme Q10 (CoQ10) in ALS. CoQ10, a cofactor in mitochondrial electron transfer, may improve the mitochondrial dysfunction in ALS. In this study, CoQ10 was safe and well tolerated in 31 subjects treated with doses as high as 3,000 mg/day for 8 months.

Construction and selection of the novel recombinant Escherichia coli strain for poly(beta-hydroxybutyrate) production

Heterogeneous cloning of Vitreoscilla hemoglobin gene (vgb), lytic genes of phage lambda with S amber mutation (S(-)RRz) and PHB biosynthetic genes (phbCAB) in the same host strain E. coli JM105 was carried out for production of poly(beta-hydroxybutyrate) (PHB). A superior novel strain, VG1 (pTU14), was constructed and selected, which contained the vgb gene in the chromosomal DNA and the plasmid pTU14 containing S(-)RRz and phbCAB genes. When cultured in 100 ml of LBG medium in a 300-ml flask, all of the exogenous genes in VG1 (pTU14) were expressed. The cell concentration of VG1 (pTU14) grown by batch culture in a flask reached 10.2 gl(-1); PHB concentration, PHB content and PHB yield, which is the ratio of the PHB accumulation to the glucose consumption, were 8.54 gl(-1), 84% and 0.43 gg(-1), respectively. When cultured by batch-feeding of glucose in a 300-ml shaking flask, the cell concentration and PHB content reached 26 gl(-1) and over 96%, respectively.

Prevalence of Type 2 diabetes in urban and rural Chinese populations in Qingdao, China

AIMS

To determine the prevalence of diabetes in the Chinese adult population in rural and urban areas of Qingdao city.

METHODS

A population-based cross-sectional study of diabetes was performed in 12 436 (5346 men) Chinese adults (20-74 years old) from 2001 to 2002. Fasting capillary whole blood glucose test (FCG) was performed in all participants and a 2-h 75-g oral glucose tolerance test in those with FCG > or = 6.1 mmol/l following initial screening. The 1999 World Health Organization diagnostic criteria for diabetes were used.

RESULTS

The age-standardized prevalence of diabetes was 6.1% (4.1% for undiagnosed and 2.1% for previously known diabetes) in adults aged 20-74 years. Diabetes prevalence increased with age up to the oldest age group (70-74); in subjects over 50 years of age, the prevalence reached 10%. Men tended to have a higher prevalence of known diabetes than women, whereas the prevalence of undiagnosed diabetes was lower in men than in women (4.6% vs. 3.3%, d.f. = 1, P = 0.001). Diabetes was more prevalent in the urban than in the rural population (6.9% vs. 5.6%, d.f. = 1, P < 0.001). However, the proportion of undiagnosed diabetes was higher in the rural than in the urban areas (70.5% vs. 58.0%, d.f. = 1, P < 0.001).

CONCLUSIONS

The prevalence of Type 2 diabetes in Qingdao city is moderately high, but much higher than reported in 1996. The large proportion of undiagnosed cases of diabetes indicates the lack of public awareness of diabetes and shortage of medical facilities. In view of the huge population in China, the results of this study emphasize the need to improve the early detection and prevention of diabetes in China to prevent the emerging diabetes epidemic.

Glutathione S-transferase polymorphisms and ovarian cancer treatment and survival

OBJECTIVE

Members of the glutathione S-transferase (GST) family have been shown to have functional polymorphisms that may affect drug metabolism and influence the effects of chemotherapy and survival from cancer. GSTM1, GSTT1, and GSTP1 genotypes were evaluated for their role in ovarian cancer treatment and survival.

METHODS

DNA was extracted from tumor tissues of 215 patients diagnosed with primary epithelial ovarian cancer. GSTM1 and GSTT1 genotypes were determined by multiplex PCR; GSTP1 genotypes were assessed with PCR-RFLP. Associations between GST polymorphisms and risk of ovarian cancer progression or death were analyzed using Cox proportional hazards regression; subgroups of patients receiving different chemotherapeutics were also evaluated.

RESULTS

GST polymorphisms were not found to be associated with patient or tumor characteristics or response to treatment. However, GSTM1 null patients were less likely to have disease progression (HR: 0.65, 95% CI: 0.43-0.99) or to die (HR: 0.68, 95% CI: 0.45-1.03) compared to patients with GSTM1. Patients with GSTM1 null and GSTP1 ile/val or val/val (reduced function) had a further reduction in risk of disease progression compared to patients with GSTM1 or GSTP1 ile/ile (HR: 0.42, 95% CI: 0.24-0.75). A similar association was also suggested for overall survival (HR: 0.61, 95% CI: 0.36-1.05). Subgroup analyses indicated that the effects of GST on survival were more pronounced among patients treated with specific chemotherapeutics.

CONCLUSION

These findings support the idea that reduced GST function may improve ovarian cancer survival after post-operative chemotherapy; evaluation of GST functional polymorphisms may help to predict ovarian cancer prognosis.

First Report of Alternaria raphani Causing Black Patches on Chinese Radish During Postharvest Storage in Canada

During November of 2003, Chinese radishes (Raphanus sativus cv. Taibai) harvested in St. Catharines, Ontario and stored in less than 1°C with 98% relative humidity (RH) and 5°C with 96% RH showed symptoms of black and dark brown, irregular patches, with or without decay. The symptoms were closely associated with skin wounds and damaged root hairs. Fungal DNA was extracted from discolored skin samples peeled from a radish, and 18S rRNA genes were amplified with fungal-specific PCR primers (1) EF4f (5'-ggaagggrtgtatttattag-3') and EF3r (5'-tcctctaaatgaccagtttg-3'). The cloned genes were sequenced using the primer EF4f and compared directly with nonredundant nucleotides in GenBank with BLAST. The results indicated that more than 75% of the fungal microflora on the diseased radish were Alternaria spp. Alternaria sp. was successfully isolated from discolored and decayed radish tissues. Morphological and molecular identification indicated that the isolated Alternaria sp. cultures belong to A. raphani, which was previously reported to cause leaf and pod blight on radish (2). For pathogenicity studies, a spore suspension (1 × 10⁵ conidia/ml) obtained from a 4-week-old A. raphani culture was used to inoculate 'Taibai' Chinese radish tissues, including inner tissues and wounded and nonwounded skin. All tests were carried out at room temperature (22 to 24°C). On inner tissue and wounded skin, symptoms of dark brown-to-black patches appeared 2 days after inoculation and progressed with time. No symptoms developed on the noninoculated control or the nonwounded, inoculated treatment. A. raphani was reisolated from symptomatic tissue. Further evidence of pathogenicity was obtained by an additional inoculation and observation of symptoms. The results indicated that A. raphani was the causal agent of the black patches observed on Chinese radish, and to our knowledge, this is the first report that A. raphani could cause a postharvest disease on Chinese radish in storage. References: (1) J. D. Van Elsas et al. J. Microbiol. Methods 43:133, 2000. (2) M. S. Sangwan et al. J. Mycol. Plant Pathol. 32:125, 2002.

Assessment of CE-MRA for the rapid detection of supra-aortic vascular disease

BACKGROUND

Contrast-enhanced MR angiography (CE-MRA) using a combined head and neck coil permits non-invasive imaging of the vasculature from the aortic arch through to the Circle of Willis in less than 2 minutes.

OBJECTIVE

To determine the accuracy of CE-MRA for the detection of vascular pathology, in particular vascular stenoses, using digital subtraction angiography (DSA) as the gold standard.

METHODS

In a prospective study of 81 patients referred for DSA, CE-MRA and DSA studies were performed within 72 hours of each other. CE-MRA was performed on a 1.5 Tesla clinical MRI scanner using a five-channel neurovascular array (head and neck coil), with dynamic tracking of the IV gadolinium bolus. CE-MRAs and DSA films were read by two interventional neuroradiologists blinded to the clinical presentation of the patient.

RESULTS

On DSA, there were 77 vascular stenoses > or =50% identified, 51 extracranial and 26 intracranial. The overall sensitivity of CE-MRA using the neurovascular array for the detection of vascular stenoses > or =50% was 57% (95% CI: 46 to 68%) with a specificity of 98% (97 to 99%). The sensitivity for the detection of extracranial vascular stenoses > or =50% was 82% (72 to 93%) with a specificity of 97% (96 to 98%). However, the sensitivity for the detection of intracranial vascular stenoses > or =50% was only 8% (0 to 18%), with a specificity of 99% (98 to 100%).

CONCLUSIONS

At this stage Contrast-enhanced MR angiography using a neurovascular coil shows promise as a rapid, specific, and noninvasive screening method for extracranial vascular disease, but not for intracranial vascular disease.

New complex Ad vectors incorporating both rtTA and tTS deliver tightly regulated transgene expression both in vitro and in vivo

Regulation of transgene expression is a major goal of gene therapy research. Previously, we have developed a complex adenovirus (Ad) vector with tetracycline-regulated expression of a Fas ligand (FasL)-green fluorescent protein (GFP) fusion protein. This vector delivered high levels of activity that was regulated by doxycycline. However, this regulation was limited by the low but significant background activity of the TRE promoter. Recently, the Tet-regulated transcriptional silencer, tTS, was reported to suppress efficiently basal TRE activity without affecting induced expression levels. Here, we report development of Ad vectors that incorporate tTS in combination with that of reverse transactivator (rtTA) coupled with TRE promoter driving transgene expression. Incorporation of tTS improved control of transgene expression in vitro, so that an induction range of over three orders of magnitude was achieved in some cell lines. Effective regulation of transgene expression was also seen in a mouse model in vivo, following systemic vector delivery. In the case of FasL-GFP expression, significant improvement in the control of apoptotic activity both in vitro and in a mouse hepatotoxicity model was demonstrated when using rtTA-tTS vectors. In conclusion, a highly effective transgene regulation system, deliverable by a single adenoviral vector, is now available.

The requirements and mechanism for capsid assembly and budding of bovine foamy virus

Little is known about assembly of non-primate foamy virus (FV) such as bovine foamy virus (BFV). To help determine the requirements for assembly of BFV, we constructed BFV-Gag expression plasmids containing all or part of the gag gene, with or without modification by addition of myristate (Myr). Each construct was transfected alone, and with pFenv, into Sf-9 insect cells. The results showed that only the entire Gag could transit through nucleus, which is required for BFV viral assembly in the cytoplasm. Unlike other retroviruses (but like primate foamy viruses), BFV requires the coexpression of the Env protein for viral particle budding. In the case of BFV, this occurs at the plasma membrane rather than the endoplasmic reticulum (ER), due to lack of a functional ER retrieval signal (ERRS). The results also showed that addition of a Myr-membrane targeting signal to the C-terminus of Gag could restore the budding from plasma membrane, implying that Myr-membrane targeting signal could substitute for Env protein in budding.