In principle, a decline in base excision repair (BER) efficiency with age should lead to genomic instability and ultimately contribute to the onset of the aging phenotype. Although multiple studies ...have indicated a negative link between aging and BER, the change of BER efficiency with age in humans has not been systematically analyzed. Here, with foreskin fibroblasts isolated from 19 donors between 20 and 64 y of age, we report a significant decline of BER efficiency with age using a newly developed GFP reactivation assay. We further observed a very strong negative correlation between age and the expression levels of SIRT6, a factor which is known to maintain genomic integrity by improving DNA double strand break (DSB) repair. Our mechanistic study suggests that, similar to the regulatory role that SIRT6 plays in DNA DSB repair, SIRT6 regulates BER in a PARP1-depdendent manner. Moreover, overexpression of SIRT6 rescues the decline of BER in aged fibroblasts. In summary, our results uncovered the regulatory mechanisms of BER by SIRT6, suggesting that SIRT6 reactivation in aging tissues may help delay the process of aging through improving BER.
Unmet medical needs are not infrequent in oncology, and these needs are usually of higher magnitude in rare cancers. The field of neuroendocrine neoplasms (NENs) has evolved rapidly during the last ...decade, and, currently, a new WHO classification is being implemented and several treatment options are available in the metastatic setting after the results of prospective phase III clinical trials. However, several questions are still unanswered, and decisions in our daily clinical practice should be made with limited evidence. In the 2016 meeting of the advisory board of the European Neuroendocrine Tumor Society (ENETS), the main unmet medical needs in the metastatic NENs setting were deeply discussed, and several proposals to try to solve them are presented in this article, including biomarkers, imaging, and therapy.
PDF
