Faculty Bibliography

A complete mode of action human relevance analysis--as distinct from mode of action (MOA) analysis alone--depends on robust information on the animal MOA, as well as systematic comparison of the animal data with corresponding information from humans. In November 2003, the International Life Sciences Institute's Risk Science Institute (ILSI RSI) published a 2-year study using animal and human MOA information to generate a four-part Human Relevance Framework (HRF) for systematic and transparent analysis of MOA data and information. Based mainly on non-DNA-reactive carcinogens, the HRF features a "concordance" analysis of MOA information from both animal and human sources, with a focus on determining the appropriate role for each MOA data set in human risk assessment. With MOA information increasingly available for risk assessment purposes, this article illustrates the further applicability of the HRF for reproductive, developmental, neurologic, and renal endpoints, as well as cancer. Based on qualitative and quantitative MOA considerations, the MOA/human relevance analysis also contributes to identifying data needs and issues essential for the dose-response and exposure assessment steps in the overall risk assessment.

The time course and differential effects of statin regimens on endothelial function after acute coronary syndromes (ACSs) are unknown and could contribute to the superiority of a more intense strategy. A subset of subjects who were enrolled in the PROVE IT-TIMI 22 trial (n = 50) underwent evaluation of vascular reactivity by high-resolution brachial ultrasound. Endothelium-dependent flow-mediated dilation (FMD) and endothelium-independent sublingual nitroglycerin-mediated dilation (NMD) were measured at baseline and at 48 hours, 1 month, and 4 months after the initiation of 40 mg of pravastatin (n = 26) or 80 mg of atorvastatin (n = 24). After 4 months, low-density lipoprotein cholesterol was decreased by 32% in the atorvastatin group but was not different from baseline after ACS in the pravastatin group. C-reactive protein decreased similarly in the 2 groups. Brachial artery diameters at rest were similar in the 2 groups and at each time point of the trial. FMD and NMD increased significantly after 4 months by 27% and 24%, respectively (p <0.05), with no difference between groups. There was no correlation between the change in FMD and the change in lipids or C-reactive protein. In subjects who had received previous statin therapy (n = 15), there was no significant variation in FMD (p = 0.140) and NMD (p = 0.129). In conclusion, initiation of statin therapy soon after ACS is associated with improvements in endothelium-dependent and independent vascular reactivities after 4 months.

PURPOSE: The purpose of this study was to determine whether curcumin would trigger cell death in the head and neck squamous cell carcinoma (HNSCC) cell lines CCL 23, CAL 27, and UM-SCC1 in a dose-dependent fashion. EXPERIMENTAL DESIGN: HNSCC cells were treated with curcumin and assayed for in vitro growth suppression using 3-(4,5-dimethylthiozol-2-yl)-2,5-diphenyl tetrazolium bromide and fluorescence-activated cell sorting analyses. Expression of p16, cyclin D1, phospho-Ikappabeta, and nuclear factor-kappabeta (NF-kappabeta) were measured by Western blotting, gel shift, and immunofluorescence. RESULTS: Addition of curcumin resulted in a dose-dependent growth inhibition of all three cell lines. Curcumin treatment resulted in reduced nuclear expression of NF-kappabeta. This effect on NF-kappabeta was further reflected in the decreased expression of phospho-Ikappabeta-alpha. Whereas the expression of cyclin D1, an NF-kappabeta-activated protein, was also reduced, there was no difference in the expression of p16 at the initial times after curcumin treatment. In vivo growth studies were done using nude mice xenograft tumors. Curcumin was applied as a noninvasive topical paste to the tumors and inhibition of tumor growth was observed in xenografts from the CAL27 cell line. CONCLUSIONS: Curcumin treatment resulted in suppression of HNSCC growth both in vitro and in vivo. Our data support further investigation into the potential use for curcumin as an adjuvant or chemopreventive agent in head and neck cancer.