Publications

Cell-matrix interactions are assumed to be important in regulating differentiation and tumor cell growth; however, the precise roles of individual matrix receptors in producing cellular responses are still unclear. We have previously described the alpha v beta 6 integrin, an epithelial cell fibronectin receptor expressed in many carcinoma cell lines. Here we show that heterologous expression of alpha v beta 6 in a human colon carcinoma cell line (SW480) enhances the proliferative capacity of these cells, both in vitro and in vivo in nude mice. This property of alpha v beta 6 correlates with the presence of an 11-amino acid region at the COOH terminus of the beta 6 cytoplasmic domain. This 11-amino acid sequence is required for the growth stimulatory effect, but not for other functions of the beta 6 cytoplasmic domain, such as promoting cell adhesion and focal contact localization.

We analyzed population-based data for respondents aged 70 and older from the Longitudinal Study on Aging. We compared mortality risk among 358 baseline-year working with 4,373 nonworking respondents. Including other demographic and health status predictors in a multiple logistic regression model, employment remained a significant predictor of survival (mortality odds ratio (OR) = 0.4). Diabetes mellitus was the only factor that displayed a mortality risk that was significantly interactive with work (OR = 3.5). These data suggest that a healthy worker effect persists in older age groups, but that within the working stratum, patterns of risk may differ as compared to those among the nonworking.