Gerald P. Murphy Cancer Foundation

Frailty refers to a state of increased vulnerability to mortality and other adverse outcomes as a consequence of age-related physiological decline. Sex differences in frailty have been reported; women are usually more frail than men. Physical frailty in men and women is the result of both sociobehavioral and biological factors, making the deciphering of the biology of sex differences in frailty challenging. Investigators have measured frailty in aging animals, including mice and dogs. We posited that companion dogs provide a useful opportunity to study sex differences in the biology of frailty, circumventing many of the sociobehavioral determinants of frailty that complicate human studies. Male-female differences in the relationship between lifetime gonad hormone exposure and late-life robustness were studied in the Exceptional Aging in Rottweilers Study (EARS), a lifetime cohort study of companion dogs with a broad range of lifetime gonad exposure. Late-life frailty was assessed by scoring dogs (135 females, 87 males) for deficit accumulation using a 34-item clinical frailty index previously developed and validated in dogs. The study outcome, late-life robustness, was defined as the lowest tertile of frailty index in the study population. Logistic regression models were constructed to assess differences in the likelihood of late-life robustness in dogs stratified into low, middle, and high lifetime gonad exposure groups. Male-female differences were probed after controlling for age at frailty scoring, gonad exposure, and other covariates. In both male and female dogs, there was a strong association between longer lifetime gonad exposure and increased likelihood of late-life robustness. Compared to dogs in the lowest gonad exposure group, dogs with highest gonad exposure had a statistically significant 3-fold (females) to 10-fold (males) higher likelihood of late-life robustness. Notably, after controlling for gonad exposure and age at frailty scoring, no male-female difference in late-life robustness was found. The research extends current interest in the biology of sex differences in frailty and provides rationale for further inquiry into the role that the hypothalamic-pituitary-gonadal axis plays in supporting late-life robustness. Studies with companion dogs represent a unique investigative opportunity to enhance our understanding of biological factors that impact sex differences and to spur the development of sex-specific anti-frailty interventions.

ABSTRACTIn an age of specialization, obstacles to interdisciplinary training and integrated intellectual growth are expected. One such obstacle to graduate-level training in gerontology is the challenge of making the biology of aging accessible to nonbiologists. In this article, the authors’ aim is to share 15 years of experience developing a pedagogical strategy that situates the biology of aging as an accessible part of interdisciplinary gerontology education for nonbiologists and biologists alike. The approach hinges on a four-pronged learning opportunity—four course offerings—that places high priority on exactitude with language and sees development of an attitude of precision with language as essential to intellectual growth. By inspiring students to master language in the key of B—Biology of Aging—we unleash a versatile method for developing cross-disciplinary discoverers prepared for a lifetime of seeing and reporting.

Investing years of intensive training, scientists ready themselves to make sense of the world. But are they prepared to make sense of a world of words? The aim of this paper is to explore the pivotal role that cultivating an attitude of precision with language could play in conditioning creative excellence in scientific discovery and education. First, the unexpected linkage between the processes of language precision and successful failure is explored. Next, an attempt is made to situate language precision within the creative process. Then, another potential dividend from developing exactitude with language is explored—the power of neologism. Finally, an attempt is made to construct a useful synthesis—one favoring a new educational prescription in which creative excellence in the sciences is informed and catalyzed by the humanities.

Our work in dogs has revealed a U-shaped dose response between selenium status and prostatic DNA damage that remarkably parallels the relationship between dietary selenium and prostate cancer risk in men, suggesting that more selenium is not necessarily better. Herein, we extend this canine work to show that the selenium dose that minimizes prostatic DNA damage also maximizes apoptosis-a cancer-suppressing death switch used by prostatic epithelial cells. These provocative findings suggest a new line of thinking about how selenium can reduce cancer risk. Mid-range selenium status (.67-.92 ppm in toenails) favors a process we call "homeostatic housecleaning"-an upregulated apoptosis that preferentially purges damaged prostatic cells. Also, the U-shaped relationship provides valuable insight into stratifying individuals as selenium-responsive or selenium-refractory, based upon the likelihood of reducing their cancer risk by additional selenium. By studying elderly dogs, the only non-human animal model of spontaneous prostate cancer, we have established a robust experimental approach bridging the gap between laboratory and human studies that can help to define the optimal doses of cancer preventives for large-scale human trials. Moreover, our observations bring much needed clarity to the null results of the Selenium and Vitamin E Cancer Prevention Trial (SELECT) and set a new research priority: testing whether men with low, suboptimal selenium levels less than 0.8 ppm in toenails can achieve cancer risk reduction through daily supplementation.

More than 14,000 people die from invasive transitional cell carcinoma (TCC) of the urinary bladder yearly in the United States. Cyclooxygenase (COX)-inhibiting drugs are emerging as potential antitumor agents in TCC. The optimal in vitro or in vivo systems to investigate COX inhibitor antitumor effects have not been defined. The purpose of this study was to determine COX-1 and COX-2 expression and antitumor effects of COX inhibitors in human TCC cell lines (HT1376, RT4, and UMUC3 cells) and xenografts derived from those cell lines. COX-2 expression (Western blot, immunocytochemistry) was high in HT1376, modest in RT4, and absent in UMUC3 cells in vitro. Similarly, COX-2 expression was noted in RT4 but not UMUC3 xenografts. COX-2 expression in HT1376 xenografts was slightly lower than that observed in vitro. None of four COX inhibitors evaluated (celecoxib, piroxicam, valeryl salicylate, and NS398) reduced TCC growth in standard in vitro proliferation assays at concentrations that could be safely achieved in vivo (< or =5 micromol/L). Higher celecoxib concentrations (> or =50 micromol/L) inhibited proliferation and induced apoptosis in all three cell lines. Celecoxib or piroxicam treatment in athymic mice significantly delayed progression of HT1376 xenografts, which express COX-2, but not UMUC3 xenografts that lack COX-2 expression. In conclusion, standard in vitro assays were not useful in predicting COX inhibitor antitumor effects observed in vivo. Athymic mice bearing TCC xenografts provide a useful in vivo system for COX inhibitor studies. Results of this study provide justification for further evaluation of COX inhibitors as antitumor agents against TCC.