Effects of Endothelin 3 on the Tumor-Angiogenic Response in a Novel Melanoma Mouse Model

Skin cancer is the most common form of cancer in the United States. Melanoma is a particular type of skin cancer, which arises from the malignant transformation of melanocytes and generally exhibits a high propensity to metastasize. Melanoma progression is dependent on angiogenesis to deliver the oxygen and nutrients required to maintain the altered metabolism of rapidly proliferating tumorigenic cells. Recent studies have implicated the growth factor Endothelin 3 (Edn3) in melanoma progression and metastasis. The aim of this study was to examine the role that Edn3 plays in the angiogenesis of melanocytic lesions. For this purpose, Dct-Grm1 transgenic mice, which spontaneously acquire melanocytic lesions through the aberrant expression of the metabotropic glutamate receptor 1 (mGluR1), were crossed with K5-Edn3 transgenic mice that overexpress Edn3. Tumors in the Dct-Grm1/K5-Edn3 experimental population were examined and compared to the control Dct-Grm1 population using immuno-fluorescent staining targeted against the vascular endothelial cell marker CD31. Proteomic arrays were also used and identified changes in the expression of specific angiogenic factors. CD31 antibody staining results revealed an increased vascular density in Dct-Grm1/K5-Edn3 tumors compared with tumors from the Dct-Grm1 controls. Analysis of the relative expression of angiogenic proteins showed an upregulation of various vascular factors in tumors from the Dct-Grm1/K5-Edn3 population, including VEGF-B, MMP-8, MMP-9, and Angiogenin. These results suggest that endothelin signaling promotes angiogenesis in melanocytic lesions. Targeting the factors upregulated by Edn3 signaling may prove effective in hindering melanoma progression.

The palatability of monosodium glutamate-enhanced vegetables as rated by Cuban-American older adults at a congregate meal site

The purpose of this study was to investigate the efficacy of using monosodium glutamate (MSG) as a means to increase palatability and prospective consumption of vegetables at a congregate meal site with Cuban-American clients. Thirty to 32 subjects participated in hedonic testing each day. MSG-enhanced (2 g MSG/500 g vegetable) and non-enhanced beets, string beans, carrots and peas were evaluated for palatability, preference and prospective consumption. Results showed that MSG significantly increased both palatability and prospective consumption of string beans (ps < .05) but not of the other 3 vegetables tested. These findings provide some evidence that MSG can be used to increase the palatability of vegetables served at congregate meal sites. However, these results suggest that older adults may not find the palatability of some vegetables to be improved by MSG and that optimal flavor enhancement cannot be achieved by adding the same amount of MSG to every vegetable.