Subchronic Exposure to Arsenic Through Drinking Water Alters Expression of Cancer-Related Genes in Rat Liver

Although arsenic exposure causes liver disease and/or hepatoma, little is known about molecular mechanisms of arsenic-induced liver toxicity or carcinogenesis. We investigated the effects of arsenic on expression of cancer-related genes in a rat liver following subchronic exposure to sodium arsenate (1, 10, 100 ppm in drinking water), by using real-time quantitative RT-PCR and immunohistochemical analyses. Arsenic accumulated in the rat liver dose-dependently and caused hepatic histopathological changes, such as disruption of hepatic cords, sinusoidal dilation, and fatty infiltration. A 1-month exposure to arsenic significantly increased hepatic mRNA levels of cyclin D1 (10 ppm), ILK (1 ppm), and p27Kip1 (10 ppm), whereas it reduced mRNA levels of PTEN (1 ppm) and β-catenin (100 ppm). In contrast, a 4-month arsenic exposure showed increased mRNA expression of cyclin D1 (100 ppm), ILK (1 ppm), and p27Kip1 (1 and 10 ppm), and decreased expression of both PTEN and β-catenin at all 3 doses. An immunohistochemical study revealed that each protein expression accords closely with each gene expression of mRNA level. In conclusion, subchronic exposure to inorganic arsenate caused pathological changes and altered expression of cyclin D1, p27Kip1, ILK, PTEN, and β-catenin in the liver. This implies that arsenic liver toxicity involves disturbances of some cancer-related molecules

Quality Improvements for Ensuring e-Retailing Success in India: Constructs and Frameworks

Part 7: Shorter PapersInternational audienceThis extended abstract presents a review of various constructs and evaluation frameworks proposed in the literature for e-Retailers. Our study shows that the existing frameworks apply to either the technical or the non-technical elements of an e-Retailing site and not both of them. Therefore, a comprehensive framework covering all aspects of quality is what is required. Furthermore, for the long run sustenance and growth of e-Retailing, it is necessary to focus on the service provided and not only the technical aspects. In the Indian context, where e-Retailing is beginning to enter a rapid growth phase, evaluation methods and metrics which are appropriate are necessary. Our extended abstract highlights the key issues that will help define these constructs