Mortality of patients with breast cancer is due overwhelmingly to metastatic spread of the disease. Although dissemination is an early event in breast cancer, extended periods of cancer cell dormancy can result in long latency of metastasis development. Deciphering the mechanisms underlying cancer cell dormancy and subsequent growth at the metastatic site would facilitate development of strategies to interfere with these processes. A challenge in this undertaking has been the lack of models for cancer cell dormancy. We have established novel experimental systems that model the bone microenvironment of the breast cancer metastatic niche. These systems are based on 3D cocultures of breast cancer cells with cell types predominant in bone marrow. We identified conditions in which cancer cells are dormant and conditions in which they proliferate. Dormant cancer cells were able to proliferate upon transfer into supportive microenvironment or upon manipulation of signaling pathways that control dormancy. These experimental systems will be instrumental for metastasis studies, particularly the study of cellular dormancy. Cancer Res; 73(23); 6886-99. Ó2013 AACR.

Age-related cognitive impairment and dementia are an increasing societal burden. Epidemiological studies indicate that lifestyle factors, e.g. physical, cognitive and social activities, correlate with reduced dementia risk; moreover, positive effects on cognition of physical/cognitive training have been found in cognitively unimpaired elders. Less is known about effectiveness and action mechanisms of physical/cognitive training in elders already suffering from Mild Cognitive Impairment (MCI), a population at high risk for dementia. We assessed in 113 MCI subjects aged 65–89 years, the efficacy of combined physical-cognitive training on cognitive decline, Gray Matter (GM) volume loss and Cerebral Blood Flow (CBF) in hippocampus and parahippocampal areas, and on brain-blood-oxygenation-level-dependent (BOLD) activity elicited by a cognitive task, measured by ADAS-Cog scale, Magnetic Resonance Imaging (MRI), Arterial Spin Labeling (ASL) and fMRI, respectively, before and after 7 months of training vs. usual life. Cognitive status significantly decreased in MCI-no training and significantly increased in MCI-training subjects; training increased parahippocampal CBF, but no effect on GM volume loss was evident; BOLD activity increase, indicative of neural efficiency decline, was found only in MCI-no training subjects. These results show that a non pharmacological, multicomponent intervention improves cognitive status and indicators of brain health in MCI subjects.