Isolation and characterization of propagable cell lines (HUNC) from the androgen-sensitive Dunning R3327H rat prostatic adenocarcinoma

The Dunning H rat prostate tumor (R3327H) is a widely used experimental model of human prostatic adenocarcinoma (CaP). The Dunning H tumor has been characterized as androgen-sensitive, androgen-receptor (AR) positive, prostate-specific antigen and prostatic acid phosphatase (PAP) positive. To date, the tumor has been maintained by serial passage in vivo because of the lack of an in vitro cell line that retains the characteristics of the in vivo tumor. The objective of the present study was to establish a propagable cell line from R3327H adenocarcinoma that maintained androgen sensitivity and expression of AR, PSA and PAP. Tissue harvested from an in vivo R3327H tumor was dissociated with collagenase and placed into Richter's improved media (with supplements). A cytokeratin-positive epithelial cell line (HUNC- E) and a vimentin-positive stromal cell line (HUNC-S) were generated from the primary culture, subcultured continuously for >300 days, and passaged >50 times. Survival of the HUNC-E cell line in vitro depended on several media supplements, including nicotinamide, insulin, transferrin, selenium and epidermal growth factor (EGF). HUNC-E cells expressed AR and produced PSA and PAP throughout the culture period, as confirmed by immunocytochemistry and Western blot analyses. Addition of 14 nM testosterone (T) or dihydrotestosterone (DHT) to HUNC-E cells, stimulated DNA synthesis as well as anchorage-independent growth and PSA production, which demonstrated the androgen-sensitive nature of the cells in vitro. When HUNC-E and HUNC-S cells were combined in a 3:1 ratio and introduced subcutaneously into syngeneic male hosts, tumors formed in 2/3 animals with an average latency of 7 months. RT-PCR and immunocytochemical characterization of the HUNC cell lines revealed that the cells expressed several growth factors and their cognate receptors, including HGF, TGF-alpha and the TGF-betas, indicating the establishment of potential autocrine loops in the neoplastic cells. The HUNC-E and HUNC-S CaP cell lines, which retain the characteristics of the epithelial and stromal components of the in vivo R3327H tumor, will allow a more thorough and informative molecular and biological analysis of prostatic adenocarcinoma.      

Zinc replenishment reduces esophageal cell proliferation and N- nitrosomethylbenzylamine (NMBA)-induced esophageal tumor incidence in zinc-deficient rats

Previous work has shown that sustained increased and decreased cell proliferation, induced by dietary zinc deficiency and caloric restriction respectively, influence the course of N- nitrosomethylbenzylamine (NMBA)-induced esophageal carcinogenesis in rats. The present study considered whether the increased cell proliferation and esophageal tumor incidence induced by zinc deficiency are reversed upon zinc replenishment. Weanling rats were maintained initially on a deficient diet containing 4 p.p.m. zinc. After 5 weeks, carcinogen-treated animals were given six intragastric doses of NMBA (2 mg/kg twice weekly). Controls were untreated. After the second NMBA dose, the rats were divided into three dietary groups. One group was continued on the deficient diet, while the other two groups were switched to diets containing either 75 or 200 p.p.m. zinc, with half of the members in each group fed ad libitum and half pair-fed with deficient rats. NMBA-untreated controls were similarly replenished. At various time points, esophageal cell proliferation was assessed in five animals from each group by immunohistochemical detection of cells in S phase, with in vivo 5-bromo-2'deoxyuridine labeling. At 11 weeks after the first dose, esophageal tumor incidence was greatly reduced, from 100% in the deficient group to 26 and 14% respectively in the replenished groups fed ad libitum 75 and 200 p.p.m. zinc and to 14 and 11% respectively in the replenished groups pair-fed 75 and 200 p.p.m. zinc. In addition, the number of tumors per esophagus was reduced from 9.93 +/- 4.25 in deficient rats, to a range of 0.11 +/- 0.31-0.30 +/- 0.54 in replenished animals. Following zinc replenishment, esophageal cell proliferation, as measured by labeling index (LI), the number of labeled cells and the total number of cells, was markedly decreased in NMBA-untreated and -treated esophagi as compared with those in corresponding deficient esophagi. Thus, the esophageal cell proliferation induced by zinc deficiency is reversed by zinc replenishment and replenished animals have a markedly lower incidence of esophageal tumors.      

Trends of atropinic (anticholinergic) exposure in the elderly: a 10‐year analysis in the French EGB database

Atropinic drugs are known to potentially induce physical and/or mental impairments in the elderly. The aim of this study was to investigate trends of atropinic exposure in patients ≥65 years in France between 2006 and 2015. A repeated cross‐sectional study was performed quarterly from January 1, 2006 to December 31, 2015, in the ‘Echantillon Généraliste des Bénéficiaires (EGB)’, a representative sample of the French population. Exposed patients were identified using the Anticholinergic Durán's list. Outcomes were rate of patients exposed to at least one atropinic drug (atropinic prevalence rate) and atropinic burden per patient (sum of atropinic burden scores). Interrupted time series were used to analyze the impact of market withdrawal of some drugs with atropinic properties during the period of the study. The number of patients ≥65 years registered in the EGB ranged from 75 611 in 2006 to 95 389 in 2015. Atropinic prevalence rate decreased significantly from 45.6% in 2006 to 33.2% in 2015 (?12.4%, slope significance P < 0.05). Subjects aged ≥85 years were the most exposed. Total atropinic burden decreased significantly between 2006 and 2015 (2.2 ± 1.7 in 2006; 2.0 ± 1.5 in 2015; slope significance P < 0.05), especially in patients ≥85 years. Market withdrawals for safety reasons of some atropinic drugs were significantly associated with a decrease in the atropinic prevalence rate (P < 0.05) and atropinic burden per patient (P < 0.05). In conclusion, atropinic drug exposure in the elderly significantly decreased in France between 2006 and 2015. This decrease can be partly explained by regulatory measures against some atropinic drugs.