Bardoxolone methyl induces apoptosis and autophagy and inhibits epithelial-to-mesenchymal transition and stemness in esophageal squamous cancer cells

Natural and synthetic triterpenoids have been shown to kill cancer cells via multiple mechanisms. The therapeutic effect and underlying mechanism of the synthetic triterpenoid bardoxolone methyl (C-28 methyl ester of 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid; CDDO-Me) on esophageal cancer are unclear. Herein, we aimed to investigate the anticancer effects and underlying mechanisms of CDDO-Me in human esophageal squamous cell carcinoma (ESCC) cells. Our study showed that CDDO-Me suppressed the proliferation and arrested cells in G2/M phase, and induced apoptosis in human ESCC Ec109 and KYSE70 cells. The G2/M arrest was accompanied with upregulated p21Waf1/Cip1 and p53 expression. CDDO-Me significantly decreased B-cell lymphoma-extra large (Bcl-xl), B-cell lymphoma 2 (Bcl-2), cleaved caspase-9, and cleaved poly ADP ribose polymerase (PARP) levels but increased the expression level of Bcl-2-associated X (Bax). Furthermore, CDDO-Me induced autophagy in both Ec109 and KYSE70 cells via suppression of the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway. There were interactions between the autophagic and apoptotic pathways in Ec109 and KYSE70 cells subject to CDDO-Me treatment. CDDO-Me also scavenged reactive oxygen species through activation of the nuclear factor (erythroid-derived 2)-related factor 2 (Nrf2) pathway in Ec109 and KYSE70 cells. CDDO-Me inhibited cell invasion, epithelial-mesenchymal transition, and stemness in Ec109 and KYSE70 cells. CDDO-Me significantly downregulated E-cadherin but upregulated Snail, Slug, and zinc finger E-box-binding homeobox 1 (TCF-8/ZEB1) in Ec109 and KYSE70 cells. CDDO-Me significantly decreased the expression of octamer-4, sex determining region Y-box 2 (Sox-2), Nanog, and B lymphoma Mo-MLV insertion region 1 homolog (Bmi-1), all markers of cancer cell stemness, in Ec109 and KYSE70 cells. Taken together, these results indicate that CDDO-Me is a promising anticancer agent against ESCC. Further studies are warranted to explore the molecular targets, efficacy and safety of CDDO-Me in the treatment of ESCC.

In vitro and in vivo assessment of docetaxel formulation developed for esophageal stents

Esophageal cancer (EC) mostly affects the elderly population and is frequently diagnosed at an advanced stage. Self-expanding metal stents (SEMS) are the most popular mode of palliation, but they are associated with reocclusion caused by tumor growth. To overcome this problem, docetaxel (DTX)-loaded polyurethane formulations were prepared for stent application. The films were evaluated against the cancer cell lines, OE-19 and OE-21, and normal esophageal cell line Het-1A. The DTX and the formulations were evaluated in vitro for the cytotoxicity and in vivo in nude mice. It was found that DTX and the formulations have a weak activity against the EC cell lines and an even weaker activity against Het-1A cell line. Preliminary in vivo studies showed skin toxicity in nude mice necessitating modification of the formulation. Reevaluation in a mouse xenograft model resulted in toxicity at high dose formulations while the low dose formulation exhibited modest advantage over commercial IV formulation; however, there was no significant difference between the commercial IV and blank formulation. DTX combination with an anti-cancer agent having complementary mode of action and non-overlapping toxicity could yield better outcome in future.

Dynamics of childhood growth and obesity: development and validation of a quantitative mathematical model

Background
Clinicians and policy makers need the ability to predict quantitatively how childhood bodyweight will respond to obesity interventions.

Methods
We developed and validated a mathematical model of childhood energy balance that accounts for healthy growth and development of obesity, and that makes quantitative predictions about weight-management interventions. The model was calibrated to reference body composition data in healthy children and validated by comparing model predictions with data other than those used to build the model.

Findings
The model accurately simulated the changes in body composition and energy expenditure reported in reference data during healthy growth, and predicted increases in energy intake from ages 5—18 years of roughly 1200 kcal per day in boys and 900 kcal per day in girls. Development of childhood obesity necessitated a substantially greater excess energy intake than for development of adult obesity. Furthermore, excess energy intake in overweight and obese children calculated by the model greatly exceeded the typical energy balance calculated on the basis of growth charts. At the population level, the excess weight of US children in 2003—06 was associated with a mean increase in energy intake of roughly 200 kcal per day per child compared with similar children in 1971—74. The model also suggests that therapeutic windows when children can outgrow obesity without losing weight might exist, especially during periods of high growth potential in boys who are not severely obese.

Interpretation
This model quantifies the energy excess underlying obesity and calculates the necessary intervention magnitude to achieve bodyweight change in children. Policy makers and clinicians now have a quantitative technique for understanding the childhood obesity epidemic and planning interventions to control it.

Funding
Intramural Research Program of the National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases.

Differentiation of cultured epithelial cells : response to toxic agents

Cell culture systems are instrumental in elucidating regulation of normal function and mechanisms of its perturbation by toxic substances. To this end, three applications of epithelial cells cultured with 3T3 feeder layer support are described. First, treatment of the premalignant human epidermal keratinocyte line SCC-12F2 with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate suppressed cell growth and differentiation. This agent produced a biphasic growth response greatly inhibiting cell growth at 1 to 10 nM, but much less above 100 nM. Expression of the differentiated functions involucrin and transglutaminase was found to be inhibited markedly at concentrations above 10 nM. Second, 3-methylcholanthrene toxicity was surveyed in a variety of rat epithelial cell types. The two most sensitive to growth inhibition were epidermal and mammary epithelial cells, while those from bladder, prostate, thyroid, and endometrium were insensitive to growth inhibition. Great differences were evident even among those cells derived from stratified squamous epithelia (epidermal, esophageal, vaginal, forestomach) despite their expression of aryl hydrocarbon hydroxylase activities to similar degrees. Finally, expression of estrogen receptors in rat endometrial cells was shown to be stimulated by the cAMP-elevating agent forskolin. Maximal stimulation of 3- to 6-fold occurred in 6 hr, compatible with a requirement for protein synthesis. Although expressing keratinocyte character (transglutaminase activity and envelope forming ability), the cells thus retain some hormonal character that may be modulated by cAMP-dependent kinase activity. Pursuit of such results will aid in understanding differences in response among cell types and species, in elucidating mechanisms of action of known toxic substances and, ultimately, in predicting toxicity of less well understood agents.

Disease mapping and regression with count data in the presence of overdispersion and spatial autocorrelation: a Bayesian model averaging approach

This paper applies the generalised linear model for modelling geographical variation to esophageal cancer incidence data in the Caspian region of Iran. The data have a complex and hierarchical structure that makes them suitable for hierarchical analysis using Bayesian techniques, but with care required to deal with problems arising from counts of events observed in small geographical areas when overdispersion and residual spatial autocorrelation are present. These considerations lead to nine regression models derived from using three probability distributions for count data: Poisson, generalised Poisson and negative binomial, and three different autocorrelation structures. We employ the framework of Bayesian variable selection and a Gibbs sampling based technique to identify significant cancer risk factors. The framework deals with situations where the number of possible models based on different combinations of candidate explanatory variables is large enough such that calculation of posterior probabilities for all models is difficult or infeasible. The evidence from applying the modelling methodology suggests that modelling strategies based on the use of generalised Poisson and negative binomial with spatial autocorrelation work well and provide a robust basis for inference.

Increasing BMI was associated with increasing risk for overall cancer incidence and mortality in middle-aged women

Question: In middle-aged women, what is the association between body mass index (BMI) and cancer incidence and mortality?METHODSDesign: Prospective cohort study with mean follow-up of 5.4 years for cancer incidence and 7.0 years for cancer mortality.Setting: Population-based study in England and Scotland, United Kingdom.Patients: 1 222 630 women 55 to 64 years of age (mean 56 y) who had no history of cancer at baseline.Risk factors: BMI at baseline, divided into 5 categories (< 22.5, 22.5 to 24.9, 25.0 to 27.4, 27.5 to 29.9, and ≥ 30 kg/m2).Outcomes: Cancer incidence and mortality, overall and for 17 specific types of cancer, identified through linkage with the National Health Service central registers.Main results: Increasing BMI was associated with increasing risks for all cancers, endometrial cancer, esophageal adenocarcinoma, kidney cancer, leukemia, postmenopausal breast cancer, multiple myeloma, pancreatic cancer, non-Hodgkin lymphoma, and ovarian cancer; and with decreasing risks for esophageal squamous cell carcinoma, lung cancer, and premenopausal breast cancer (Table). Risks for stomach, colorectal, cervical, bladder, and brain cancer and malignant melanoma did not vary by BMI. Patterns for cancer mortality were similar to those for cancer incidence: Relative risk for death from any type of cancer was 1.06 (95% CI 1.02 to 1.10) per 10-unit increase in BMI. In postmenopausal women, the estimated proportion of cancer attributable to being overweight or obese (BMI ≥ 25 kg/m2) was 5% for all cancers and about 50% for endometrial cancer and esophageal adenocarcinoma.Conclusions: In middle-aged women, increasing body mass index was associated with increasing risk for cancer incidence and mortality overall. High body mass index increased risk for some types of cancer but reduced risk for other types.

Investigating relative respiratory effort signals during mixed sleep apnea using photoplethysmogram

Sleep disordered breathing does show different types of events. These are obstructive apnea events, central apnea events and mixed sleep apnea (MSA) which have a central component with a pause in airflow without respiratory effort followed by an obstructive component with respiratory effort. The esophageal pressure (Pes) is the accurate method to assess respiratory effort. The aim of the present study is to investigate whether the features extracted from photo-plethysmogram (PPG) could relate with the changes in Pes during MSA. Therefore, Pes and PPG signals during 65 pre-scored MSA events and 10 s preceding the events were collected from 8 patients. Pulse intervals (PPI), Pulse wave amplitudes (PWA) and wavelet decomposition (Wv) of PPG signals at level 8 (0.15-0.32 Hz) were derived from PPG signals. Results show that significant correlations (r = 0.63, p < 0.01; r = 0.42, p < 0.05; r = 0.8, p < 0.01 for OSA part) were found between reductions in Pes and that in PPG based surrogate respiratory signals PPI, PWA and Wv. Results suggest that PPG based relative respiratory effort signal can be considered as an alternative to Pes as a means of measuring changes in inspiratory effort when scoring OSA and CSA parts of MSA events.