A multi-site trial of an electronic health integrated physical activity promotion intervention in breast and endometrial cancers survivors: MyActivity study protocol.

Despite the known benefits of moderate-to-vigorous physical activity (MVPA) for breast and endometrial cancer survivors, most are insufficiently active, interventions response is heterogeneous, and MVPA programming integration into cancer care is limited. A stepped care approach, in which the least resource-intensive intervention is delivered first and additional components are added based on individual response, is one strategy to enhance uptake of physical activity programming. However, the most effective intervention augmentation strategies are unknown. In this singly randomized trial of post-treatment, inactive breast and endometrial cancer survivors (n = 323), participants receive a minimal intervention including a Fitbit linked with their clinic's patient portal and, in turn, the electronic health record (EHR) with weekly feedback delivered via the portal. MVPA progress summaries are sent to participants' oncology team via the EHR. MVPA adherence is evaluated at 4, 8, 12, 16 and 20 weeks; non-responders (those meeting ≤80% of the MVPA goal over previous 4 weeks) at each timepoint are randomized once for the remainder of the 24-week intervention to one of two "step-up" conditions: (1) online gym or (2) coaching calls, while responders continue with the minimal Fitbit+EHR intervention. The primary outcome is ActiGraph-measured MVPA at 24 and 48 weeks. Secondary outcomes include symptom burden and functional performance at 24 and 48 weeks. This trial will inform development of an effective, scalable, and tailored intervention for survivors by identifying non-responders and providing them with the intervention augmentations necessary to increase MVPA and improve health outcomes. Clinical Trials Registration # NCT04262180.

MusTRD can regulate postnatal fiber-specific expression.

Human MusTRD1alpha1 was isolated as a result of its ability to bind a critical element within the Troponin I slow upstream enhancer (TnIslow USE) and was predicted to be a regulator of slow fiber-specific genes. To test this hypothesis in vivo, we generated transgenic mice expressing hMusTRD1alpha1 in skeletal muscle. Adult transgenic mice show a complete loss of slow fibers and a concomitant replacement by fast IIA fibers, resulting in postural muscle weakness. However, developmental analysis demonstrates that transgene expression has no impact on embryonic patterning of slow fibers but causes a gradual postnatal slow to fast fiber conversion. This conversion was underpinned by a demonstrable repression of many slow fiber-specific genes, whereas fast fiber-specific gene expression was either unchanged or enhanced. These data are consistent with our initial predictions for hMusTRD1alpha1 and suggest that slow fiber genes contain a specific common regulatory element that can be targeted by MusTRD proteins.