Organotypic culture model of pancreatic cancer demonstrates that stromal cells modulate E-cadherin, beta-catenin, and Ezrin expression in tumor cells.

Pancreatic cancer is characterized by an intense stromal reaction. Reproducible three-dimensional in vitro systems for exploring interactions of the stroma with pancreatic cancer cells have not previously been available, prompting us to develop such a model. Cancer cells were grown on collagen/Matrigel and embedded with or without stromal cells (hTERT-immortalized human PS-1 stellate cells or MRC-5 fibroblasts) for 7 days. Proliferation and apoptosis, as well as important cell-cell adhesion and cytoskeleton-regulating proteins, were studied. PS-1 cells were confirmed as stellate based on the expression of key cytoskeletal proteins and lipid vesicles. Capan-1, and to a lesser extent PaCa-3, cells differentiated into luminal structures, exhibiting a central apoptotic core with a proliferating peripheral rim and an apico-basal polarity. Presence of either stromal cell type translocated Ezrin from apical (when stromal cells were absent) to basal aspects of cancer cells, where it was associated with invasive activity. Interestingly, the presence of 'normal' (not tumor-derived) stromal cells induced total tumor cell number reduction (P < 0.005) associated with a significant decrease in E-cadherin expression (P < 0.005). Conversely, beta-catenin expression was up-regulated (P < 0.01) in the presence of stromal cells with predominant cytoplasmic expression. Moreover, patient samples confirmed that these data recapitulated the clinical situation. In conclusion, pancreatic organotypic culture offers a reproducible, bio-mimetic, three-dimensional in vitro model that allows examination of the interactions between stromal elements and pancreatic cancer cells.

Predictors of asthma severity during the pilgrimage to Mecca (Hajj).

INTRODUCTION: The annual pilgrimage to Mecca (Hajj) is one of the largest gatherings in the world and thus its participants are exposed to various communicable and noncommunicable diseases. This provides an opportunity to study travel epidemiology. OBJECTIVES: The aim of the study was to estimate the predictors of asthma severity during the Hajj. PATIENTS AND METHODS: The study cohort was recruited from patients who presented to the emergency department (ED) of the King Abdul Aziz Hospital, Mecca, Saudi Arabia, between December 3 and 18, 2008 (5-20 Dhul-Hijjah 1429 H). We included newly diagnosed and previously documented cases presenting with asthma symptoms. Sociodemographic and clinical data were collected and the risk factors were assessed. The severity of asthma exacerbation was measured according to the National Heart, Lung, and Blood Institute guidelines. Data were analyzed using the SPSS software. RESULTS: The study involved 58 subjects, including 38 women (65.5%). There were 27 subjects (46.6%) with mild asthma attack, 18 (31%) with moderate asthma attack, and no cases with life-threatening asthma. Insignificantly increased risk of severe asthma attack was observed in the following groups: women, people aged 46-60 years, pilgrims (hajis) who did not belong to a hajj group, non-hajis, illiterates, and nonsmokers - the odds ratio (OR) (95% confidence interval [CI]) was 3.7 (0.7-18.5), 1.7 (0.5-6.3), 2.4 (0.7-8.5), 5.1 (0.6-44.1), 2.3 (0.7-9.1), and 2.0 (0.4-10.4), respectively. Forty-six subjects (79.3%) had a history of allergy to components of smoke, detergents, dust, animal dander, and perfumes, while only 5 patients (8.6%) had drug allergy. High risk of severe asthma was observed in subjects with a history of drug allergy, as well as in obese subjects and those who often presented to the ED - OR (95% CI) was 6.5 (0.9-43.9), 18.0 (4.0-80.7), and 3.1 (0.8-11.5), respectively. CONCLUSIONS: Higher risk of severe asthma attack was observed in women, people aged 46-60 years, hajis who did not belong to a hajj group, non-hajis, illiterates, nonsmokers, obese patients, and those who often presented to the ED within the previous 12 months due to asthma exacerbation.