Metastatic breast cancer remains challenging to treat, and most patients ultimately progress on therapy. This acquired drug resistance is largely due to drug-refractory sub-populations (subclones) within heterogeneous tumors. Here, we track the genetic and phenotypic subclonal evolution of four breast cancers through years of treatment to better understand how breast cancers become drug-resistant. Recurrently appearing post-chemotherapy mutations are rare. However, bulk and single-cell RNA sequencing reveal acquisition of malignant phenotypes after treatment, including enhanced mesenchymal and growth factor signaling, which may promote drug resistance, and decreased antigen presentation and TNF-α signaling, which may enable immune system avoidance. Some of these phenotypes pre-exist in pre-treatment subclones that become dominant after chemotherapy, indicating selection for resistance phenotypes. Post-chemotherapy cancer cells are effectively treated with drugs targeting acquired phenotypes. These findings highlight cancer’s ability to evolve phenotypically and suggest a phenotype-targeted treatment strategy that adapts to cancer as it evolves.
Exposure of mice to hyperoxia induces alveolar epithelial cell (AEC) injury, acute lung injury and death. Overexpression of granulocyte-macrophage colony-stimulating factor (GM-CSF) in the lung protects against these effects, although the mechanisms are not yet clear. Hyperoxia induces cellular injury via effects on mitochondrial integrity, associated with induction of proapoptotic members of the Bcl-2 family. We hypothesized that GM-CSF protects AEC through effects on mitochondrial integrity. MLE-12 cells (a murine type II cell line) and primary murine type II AEC were subjected to oxidative stress by exposure to 80% oxygen and by exposure to H(2)O(2). Exposure to H(2)O(2) induced cytochrome c release and decreased mitochondrial reductase activity in MLE-12 cells. Incubation with GM-CSF significantly attenuated these effects. Protection induced by GM-CSF was associated with Akt activation. GM-CSF treatment also resulted in increased expression of the antiapoptotic Bcl-2 family member, Mcl-1. Primary murine AEC were significantly more tolerant of oxidative stress than MLE-12 cells. In contrast to MLE-12 cells, primary AEC expressed significant GM-CSF at baseline and demonstrated constitutive activation of Akt and increased baseline expression of Mcl-1. Treatment with exogenous GM-CSF further increased Akt activation and Mcl-1 expression in primary AEC. Conversely, suppression of AEC GM-CSF expression by use of GM-CSF-specific small interfering RNA resulted in decreased tolerance of oxidative stress, Furthermore, silencing of Mcl-1 prevented GM-CSF-induced protection. We conclude that GM-CSF protects alveolar epithelial cells against oxidative stress-induced mitochondrial injury via the Akt pathway and its downstream components, including Mcl-1. Epithelial cell-derived GM-CSF may contribute to intrinsic defense mechanisms limiting lung injury.
Objective The study sought to evaluate a novel electronic health record (EHR) add-on application for chronic disease management that uses an integrated display to decrease user cognitive load, improve efficiency, and support clinical decision making. Materials and Methods We designed a chronic disease management application using the technology framework known as SMART on FHIR (Substitutable Medical Applications and Reusable Technologies on Fast Healthcare Interoperability Resources). We used mixed methods to obtain user feedback on a prototype to support ambulatory providers managing chronic obstructive pulmonary disease. Each participant managed 2 patient scenarios using the regular EHR with and without access to our prototype in block-randomized order. The primary outcome was the percentage of expert-recommended ideal care tasks completed. Timing, keyboard and mouse use, and participant surveys were also collected. User experiences were captured using a retrospective think-aloud interview analyzed by concept coding. Results With our prototype, the 13 participants completed more recommended care (81% vs 48%; P < .001) and recommended tasks per minute (0.8 vs 0.6; P = .03) over longer sessions (7.0 minutes vs 5.4 minutes; P = .006). Keystrokes per task were lower with the prototype (6 vs 18; P < .001). Qualitative themes elicited included the desire for reliable presentation of information which matches participants’ mental models of disease and for intuitive navigation in order to decrease cognitive load. Discussion Participants completed more recommended care by taking more time when using our prototype. Interviews identified a tension between using the inefficient but familiar EHR vs learning to use our novel prototype. Concept coding of user feedback generated actionable insights. Conclusions Mixed methods can support the design and evaluation of SMART on FHIR EHR add-on applications by enhancing understanding of the user experience.
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