Effect of estrogen on growth and apoptosis in esophageal adenocarcinoma cells

The epidemiology of esophageal adenocarcinoma demonstrates a strong gender bias with a sex ratio of 8-9:1 in favor of males. A potential explanation for this is that estrogen might protect against esophageal adenocarcinoma. Estrogen has previously been shown to stimulate apoptosis in esophageal squamous cancer cells. However, the effect of estrogen on esophageal adenocarcinoma cells has not been determined. We used immunoblotting analysis to determine the expression of estrogen receptors, cell adhesion marker E-cadherin, and proliferation marker Ki-67 in cell lines derived from esophageal adenocarcinoma (OE-19, OE-33) and Barrett's esophagus (QhTRT, ChTRT, GihTRT). Estrogen and selective estrogen receptor modulator (SERM)-dependent effects on cell growth were determined by the CellTiter-96 Aqueous Proliferation Assay. Apoptosis was determined by Annexin V/Propidium Iodide cell labeling and flow cytometry. We detected that physiological and supra-physiological concentrations of 17β-estradiol and SERM decreased cell growth in esophageal adenocarcinoma cells. In Barrett's esophagus cells (QhTRT, ChTRT), decreased growth was also detected in response to estrogen/SERM. The level of estrogen receptor expression in the cell lines correlated with the level of anti-growth effects induced by the receptor agonists. Flow cytometry analysis confirmed estrogen/SERM stimulated apoptosis in esophageal adenocarcinoma cells. Estrogen/SERM treatments were associated with a decrease in the expression of Ki-67 and an increase in E-cadherin expression in esophageal adenocarcinoma cells. This study suggests that esophageal adenocarcinoma and Barrett's esophagus cells respond to treatment with selective estrogen receptor ligands, resulting in decreased cell growth and apoptosis. Further research to explore potential therapeutic applications is warranted.

Is atropine needed with ketamine sedation? A prospective, randomised, double blind study

OBJECTIVE

To compare atropine with placebo as an adjunct to ketamine sedation in children undergoing minor painful procedures. Outcome measures included hypersalivation, side effect profile, parental/patient satisfaction, and procedural success rate.

METHODS

Children aged between 1 and 16 years of age requiring ketamine procedural sedation in a tertiary emergency department were randomised to receive 0.01 mg/kg of atropine or placebo. All received 4 mg/kg of intramuscular ketamine. Tolerance and sedation scores were recorded throughout the procedure. Side effects were recorded from the start of sedation until discharge. Parental and patient satisfaction scores were obtained at discharge and three to five days after the procedure, with the opportunity to report side effects encountered at home.

RESULTS

A total of 83 patients aged 13 months to 14.5 years (median age 3.4 years) were enrolled over a 16 month period. Hypersalivation occurred in 11.4% of patients given atropine compared with 30.8% given placebo (odds ratio (OR) 0.29, 95% confidence interval (CI) 0.09 to 0.91). A transient rash was observed in 22.7% of the atropine group compared with 5.1% of the placebo group (OR 5.44, 95% CI 1.11 to 26.6). Vomiting during recovery occurred in 9.1% of atropine patients compared with 25.6% of placebo patients (OR 0.29, 95% CI 0.09 to 1.02). There was a trend towards better tolerance in the placebo group. No patient experienced serious side effects.

CONCLUSION

Ketamine sedation was successful and well tolerated in all cases. The use of atropine as an adjunct for intramuscular ketamine sedation in children significantly reduces hypersalivation and may lower the incidence of post-procedural vomiting. Atropine is associated with a higher incidence of a transient rash. No serious adverse events were noted.

Association between antenatal cytokine production and the development of atopy and asthma at age 6 years

BACKGROUND

Various lines of evidence suggest that antenatal factors are important in determining susceptibility to atopy and asthma. One possible mechanism is cytokines, production of which in the placenta is high throughout gestation and which protect placental integrity via control of local immunological homoeostasis. We investigated antenatal cytokine concentrations in a prospective birth cohort, intensively monitored for atopy and asthma outcomes at age 6 years.

METHODS

Cryopreserved cord-blood serum samples from 407 children were assayed for interleukins 4, 5, 6, 10, 12, and 13, interferon gamma, and tumour necrosis factor alpha (TNFalpha). Associations between family, antenatal, and perinatal factors, cord-blood cytokine concentrations, and atopy or asthma outcomes were analysed by logistic regression. Causal effects of cytokines on outcomes were estimated by propensity scores based on family, antenatal, and perinatal factors.

FINDINGS

Detectable cord-blood concentrations of interleukin 4 and interferon gamma were each associated with lower risk of physician-diagnosed asthma (adjusted odds ratios 0.60 [95% CI 0.37-0.99] and 0.60 [0.37-0.97] respectively), current asthma (0.59 [0.33-1.00] and 0.39 [0.22-0.71]), and current wheeze (0.55 [0.32-0.93] and 0.52 [0.31-0.90]) and atopy (sensitisation to some inhalant allergens) outcomes at 6 years. High concentrations of TNFalpha were associated with lower risk of atopy but not with asthma risk. These associations were broadly unaltered by propensity-score adjustment. Maternal smoking was associated with higher risk of both wheeze at 6 years and lower concentrations of interleukin 4 and interferon gamma in cord blood.

INTERPRETATION

The mechanism underlying attenuated T-helper-1/T-helper-2 cytokine production in high-risk children also apparently operates in control of cytokine production in the fetoplacental unit. The finding that this mechanism is dysregulated by maternal smoking suggests it is a target for antenatal environmental factors relevant to asthma aetiology.

Reciprocal patterns of allergen-induced GATA-3 expression in peripheral blood mononuclear cells from atopics vs. non-atopics

BACKGROUND

T helper (Th)2 cytokines are considered to play a central role in the induction and expression of allergic disease. However, the relative importance of individual cytokines is unclear, and overall disease pathogenesis appears to involve the coordinate activities of a range of Th2 cytokines acting in sequence or in parallel. The present study examines an alternative approach to the study of cytokine gene function in atopy, focusing instead upon T cell transcription factors (TFs) which play a role in the regulation of multiple cytokine genes.

OBJECTIVE

To investigate the allergen-induced expression of the TF GATA-3 and c-Maf in peripheral blood mononuclear cells (PBMCs) and in cytokine-driven Th polarization.

METHODS

PBMC from house dust mite (HDM)-atopic and non-atopics were stimulated in vitro with allergen or anti-CD3/IL-2. TF expression was analysed by semiquantitative RT-PCR and major findings were validated by real-time PCR. Cell separations were performed to analyse the contribution of CD45RO+ cells. CD4+ cord blood cells were Th1 or Th2 polarized in vitro by exogenous cytokines and TF expression analysed by Northern blot and real-time PCR. Results We demonstrate for the first time that during differentiation of CD4+ CD45RA+ naïve human T cells towards Th2 commitment, and during allergen-specific reactivation of peripheral CD4+ CD45RO+ Th2 memory cells in established atopics, expression of the Th2-associated TF GATA-3 is rapidly up-regulated, whereas T cells from non-atopics display equally rapid GATA-3 down-regulation under identical conditions of allergen stimulation.

CONCLUSION

These findings identify Th2-associated TFs as key determinants of the atopic phenotype, suggesting their unique potential as therapeutic targets for disease control.

"Bystander" amplification of PBMC cytokine responses to seasonal allergen in polysensitized atopic children

BACKGROUND

Atopic children show increased expression and production of the Th2-associated cytokines IL-4, IL-5, IL-13, and IL-9 from PBMCs after stimulation with allergen, but it has previously not been clearly determined whether the Th2-cytokine production is restricted to the inhalant allergen the child is sensitized to, and whether perennial or seasonal allergens induce different cytokine responses. Our purpose was to determine whether in vitro Th2 cytokine production is specific to the sensitizing allergen, and to compare the cytokine responses to a perennial and a seasonal allergen in monosensitized and polysensitized children.

METHODS

Using semiquantitative RT-PCR, we analyzed the expression of the cytokines IL-4, IL-5, IL-13, IL-9, IL-10, and IFN-gamma after stimulation of PBMCs with house-dust-mite (HDM) or ryegrass allergen. The cells were sampled from groups of 6-year-old children sensitized to either HDM (n=20) or ryegrass (n=24), or to both allergens (n=20), as well as from a nonatopic group (n=20).

RESULTS

After stimulation with HDM allergen, PBMCs from children sensitized only to HDM expressed increased mRNA levels of the Th2 cytokines, but not of IL-10 and IFN-gamma, whereas ryegrass stimulation did not result in increased cytokine expression. PBMCs from children sensitized to HDM and ryegrass expressed increased Th2 cytokines after stimulation with either of the two allergens. In contrast, PBMCs from children sensitized only to ryegrass did not express increased levels after stimulation with either of the allergens.

CONCLUSIONS

The expression of Th2 cytokines after in vitro stimulation of PBMCs from atopic children is specific to the sensitizing allergen, indicating that atopic status per se does not affect the type of T-cell response. In addition, T cells specific to seasonal allergens circulate in the blood out of season only if the child is concomitantly sensitized to a perennial allergen.

Promoter analysis of the murine T-cell protein tyrosine phosphatase gene

The T-cell protein tyrosine phosphatase (TC PTP) is expressed ubiquitously at all stages of mammalian development. However, mRNA levels fluctuate in a cell-cycle-dependent manner, reaching peak levels in late G1, and rapidly decreasing in S phase. Furthermore, TC PTP being present in higher amounts in lymphoid tissues, we have recently shown that it is essential for proper maintenance of both the bone marrow micro-environment and B- and T-cell functions. In order to better understand the elements controlling the expression pattern of this gene, we have isolated and characterized approx. 4kb of the murine TC PTP promoter. DNA sequencing of the proximal 5' region revealed the absence of both TATAA and CAAT boxes. Primer extension analysis and S1 nuclease mapping techniques identified multiple transcription initiation sites. Functional promoter activity was determined using transfection experiments of promoter deletion constructs fused to a CAT reporter construct. Our results indicate that the minimal promoter sequence required for functional expression is contained within the first 147bp of the TC PTP promoter. In addition, consistent with the cell-cycle-dependent expression of TC PTP, we localized a domain between 492 and 1976bp from the transcription initiation site through which repression occurs. In conclusion, although initiator-driven transcription allows for ubiquitous expression of TC PTP, we define general transcription motifs present within the promoter that may mediate specific modulations of the TC PTP gene.