Findings from the Honolulu Heart Program, which targeted physically capable elderly men, suggest that the risk of coronary heart disease is reduced with increases in distance walked. Combined with evidence that suggests that an active lifestyle reduces the risk of cardiovascular disease in younger and more diverse groups, this suggests that important health benefits could be derived by encouraging the elderly to walk.
Pathogenesis and growth of three common women's cancers (breast, endometrium and ovary) are linked to estrogen. A single gene encodes the key enzyme for estrogen biosynthesis named aromatase, inhibition of which effectively eliminates estrogen production in the entire body. Aromatase inhibitors successfully treat breast cancer, whereas their roles in endometrial and ovarian cancers are less clear. Ovary, testis, adipose tissue, skin, hypothalamus and placenta express aromatase normally, whereas breast, endometrial and ovarian cancers overexpress aromatase and produce local estrogen exerting paracrine and intracrine effects. Tissue-specific promoters distributed over a 93-kb regulatory region upstream of a common coding region alternatively control aromatase expression. A distinct set of transcription factors regulates each promoter in a signaling pathway- and tissue-specific manner. In cancers of breast, endometrium and ovary, aromatase expression is primarly regulated by increased activity of the proximally located promoter I.3/II region. Promoters I.3 and II lie 215 bp from each other and are coordinately stimulated by PGE(2) via a cAMP-PKA-dependent pathway. In breast adipose fibroblasts exposed to PGE(2) secreted by malignant epithelial cells, PKC is also activated, and this potentiates cAMP-PKA-dependent induction of aromatase. Thus, inflammatory substances such as PGE(2) may play important roles in inducing local production of estrogen that promotes tumor growth.
We examined alterations in the p53 tumor suppressor gene and the ras and HER-2/neu oncogenes in chicken ovarian cancers to determine if these tumors have genetic alterations similar to those in human ovarian adenocarcinomas. Mutations in the p53 tumor suppressor gene and the H-ras and K-ras oncogenes were assessed by direct sequencing in 172 ovarian cancers obtained from 4-year-old birds enrolled at age 2 in two separate 2-year chemoprevention trials. Birds in trial B had approximately twice as many lifetime ovulations as those in trial A. Immunohistochemical staining for the HER-2/neu oncogene was done on a subset of avian ovarian and oviductal adenocarcinomas. Alterations in p53 were detected in 48% of chicken ovarian cancers. Incidence of p53 alterations varied according to the number of lifetime ovulations, ranging from 14% in trial A to 96% in trial B (P < 0.01). No mutations were seen in H-ras, and only 2 of 172 (1.2%) tumors had K-ras mutations. Significant HER-2/neu staining was noted in 10 of 19 ovarian adenocarcinomas but in only 1 of 17 oviductal adenocarcinomas. Similar to human ovarian cancers, p53 alterations are common in chicken ovarian adenocarcinomas and correlate with the number of lifetime ovulations. Ras mutations are rare, similar to high-grade human ovarian cancers. HER-2/neu overexpression is common and may represent a marker to exclude an oviductal origin in cancers involving both the ovary and oviduct.
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