Inhibition of interferon-signalling halts cancer-associated fibroblast-dependent protection of breast cancer cells from chemotherapy.

BACKGROUND: Triple negative breast cancers (TNBC) have poor prognoses despite aggressive treatment with cytotoxic chemotherapy. Cancer-associated fibroblasts (CAFs) are prominent in tumour stroma. Our hypothesis was that CAFs modulate chemotherapy sensitivity. METHODS: TNBC cells and breast fibroblasts were cultured; survival after chemotherapeutics was assessed using luciferase or clonogenic assays. Signalling was investigated using transcriptomics, reporters, recombinant proteins and blocking antibodies. Clinical relevance was investigated using immunohistochemistry. RESULTS: Breast CAFs dose-dependently protected TNBC cell lines MDA-MB-231 and MDA-MB-157, but not MDA-MB-468s, from chemotherapy. CAF-induced protection was associated with interferon (IFN) activation. CAFs were induced to express IFNß1 by chemotherapy and TNBC co-culture, leading to paracrine activation in cancer cells. Recombinant IFNs were sufficient to protect MDA-MB-231 and MDA-MB-157 but not MDA-MB-468 cells. In TNBC patients, IFNß1 expression in CAFs correlated with cancer cell expression of MX1, a marker of activated IFN signalling. High expression of IFNß1 (CAFs) or MX1 (tumour cells) correlated with reduced survival after chemotherapy, especially in claudin-low tumours (which MDA-MB-231 and MDA-MB-157 cells represent). Antibodies that block IFN receptors reduced CAF-dependent chemoprotection. CONCLUSIONS: CAF-induced activation of IFN signalling in claudin-low TNBCs results in chemoresistance. Inhibition of this pathway represents a novel method to improve breast cancer outcomes.

Transcriptome profiles of stem-like cells from primary breast cancers allow identification of ITGA7 as a predictive marker of chemotherapy response.

BACKGROUND: Breast cancer stem cells (BCSCs) are drivers of therapy-resistance, therefore are responsible for poor survival. Molecular signatures of BCSCs from primary cancers remain undefined. Here, we identify the consistent transcriptome of primary BCSCs shared across breast cancer subtypes, and we examine the clinical relevance of ITGA7, one of the genes differentially expressed in BCSCs. METHODS: Primary BCSCs were assessed using immunohistochemistry and fluorescently labelled using Aldefluor (n = 17). Transcriptomes of fluorescently sorted BCSCs and matched non-stem cancer cells were determined using RNA-seq (n = 6). ITGA7 expression was examined in breast cancers using immunohistochemistry (n = 305), and its functional role was tested using siRNA in breast cancer cells. RESULTS: Proportions of BCSCs varied from 0 to 9.4%. 38 genes were significantly differentially expressed in BCSCs; genes were enriched for functions in vessel morphogenesis, motility, and metabolism. ITGA7 was found to be significantly downregulated in BCSCs, and low expression significantly correlated with reduced survival in patients treated with chemotherapy, and with chemoresistance in breast cancer cells in vitro. CONCLUSIONS: This study is the first to define the molecular profile of BCSCs from a range of primary breast cancers. ITGA7 acts as a predictive marker for chemotherapy response, in accordance with its downregulation in BCSCs.

Factors affecting nurse practitioners' integration of evidence into practice.

BACKGROUND: Evidence-based clinical practice guidelines bridge the gap between clinical practice and research, improve patient outcomes, promote consistency of care, and enhance quality of care. However, guideline adherence varies widely among individual providers and organizations. PURPOSE: To identify factors that facilitate or impede nurse practitioners' integration of guideline recommendations into practice. METHODS: Every nurse practitioner in Alabama was invited to complete an online 45-question survey evaluating beliefs and attitudes regarding evidence-based guidelines, facilitators and barriers to implementation, and utilization of information resources in patient care. RESULTS: The five most commonly identified barriers to evidence-based guideline implementation in participants' current work settings are patients with multiple comorbidities, time constraints, pressure from patients to provide nonrecommended care, insufficient staffing, and inadequate financial resources. The five most commonly identified facilitators in participants' current work settings are easy access to guidelines, support from leadership, free access to guidelines, in-person education regarding a guideline, and clinical decision support software programs. Participants expressed a desire for free and easy access to evidence-based practice (EBP) guidelines and clinical decision support programs, as well as education regarding guidelines and opportunities to discuss evidence with colleagues. IMPLICATIONS FOR PRACTICE: The barriers and facilitators of guideline implementation that were identified in this study should be useful in the development and refinement of future studies and interventions to enhance guideline implementation among individuals and organizations.

Analysis of Secondary Surgeries after Immediate Breast Reconstruction for Cancer Compared with Risk Reduction.

This study sets out to compare reconstructive practice between patients undergoing immediate breast reconstruction (IBR) for cancer and those who opted for risk reduction (RR), with an emphasis on examining patterns of secondary surgery. METHODS: Data collection was performed for patients undergoing mastectomy and IBR at a teaching hospital breast unit (2013-2016). RESULTS: In total, 299 patients underwent IBR (76% cancer versus 24% RR). Implant-based IBR rate was similar in both groups (58% cancer versus 63% RR). Reconstruction loss (5.3% cancer versus 4.2% RR) and complication (16% cancer versus 12.9% RR) rates were similar. Cancer patients were more likely to undergo secondary surgery (68.4% versus 56.3%; P = 0.025), including contralateral symmetrization (22.8% versus 0%) and conversion to autologous reconstruction (5.7% versus 1.4%). Secondary surgeries were mostly planned for cancer patients (72% planned versus 28% unplanned), with rates unaffected by adjuvant therapies. This distribution was different in RR patients (51.3% planned versus 48.7% unplanned). The commonest secondary procedure was lipomodeling (19.7% cancer versus 23.9% RR). For cancer patients, complications resulted in a significantly higher unplanned secondary surgery rate (82.5% versus 38.8%; P = 0.001) than patients without complications. This was not evident in the RR patients, where complications did not lead to a significantly higher unplanned surgery rate (58.9% versus 35.2%; P = 0.086). CONCLUSIONS: Most of the secondary surgeries were planned for cancer patients. However, complications led to a significantly higher rate of unplanned secondary surgery. Approximately 1 in 4 RR patients received unplanned secondary surgery, which may be driven by the desire to achieve an optimal aesthetic outcome.

Genomic and Expression Analyses Define MUC17 and PCNX1 as Predictors of Chemotherapy Response in Breast Cancer.

Poor-prognosis breast cancers are treated with cytotoxic chemotherapy, but often without any guidance from therapy predictive markers because universally accepted markers are not currently available. Treatment failure, in the form of recurrences, is relatively common. We aimed to identify chemotherapy predictive markers and resistance pathways in breast cancer. Our hypothesis was that tumor cells remaining after neoadjuvant chemotherapy (NAC) contain somatic variants causing therapy resistance, while variants present pre-NAC but lost post-NAC cause sensitivity. Whole-exome sequencing was performed on matched pre- and post-NAC cancer cells, which were isolated by laser microdissection, from 6 cancer cases, and somatic variants selected for or against by NAC were identified. Somatic variant diversity was significantly reduced after therapy (P < 0.05). MUC17 variants were identified in 3 tumors and were selected against by NAC in each case, while PCNX1 variants were identified in 2 tumors and were selected for in both cases, implicating the function of these genes in defining chemoresponse. In vitro knockdown of MUC17 or PCNX1 was associated with significantly increased or decreased chemotherapy sensitivity, respectively (P < 0.05), further supporting their roles in chemotherapy response. Expression was tested for predictive value in two independent cohorts of chemotherapy-treated breast cancers (n = 53, n = 303). Kaplan-Meier analyses revealed that low MUC17 expression was significantly associated with longer survival after chemotherapy, whereas low PCNX1 was significantly associated with reduced survival. We concluded that therapy-driven selection of somatic variants allows identification of chemotherapy response genes. With respect to MUC17 and PCNX1, therapy-driven selection acting on somatic variants, in vitro knockdown data concerning drug sensitivity, and survival analysis of expression levels in patient cohorts all define the genes as mediators of and predictive markers for chemotherapy response in breast cancer.

Hyperkalemia during general anesthesia in two Greyhounds.

CASE DESCRIPTION: A 36-kg (79-lb) castrated male Greyhound (dog 1) and a 25-kg (55 lb) spayed female Greyhound (dog 2) underwent general anesthesia for dental care with similar perianesthetic protocols on multiple occasions from 2013 to 2016. Both dogs had periodontal disease but were otherwise deemed healthy. Both dogs developed clinically relevant hyperkalemia, with signs including loss of P waves on ECG tracings, during multiple anesthetic events. CLINICAL FINDINGS: Dog 1 developed hyperkalemia during 2 of 2 anesthetic events, with ECG changes noted during the first event. Dog 2 developed hyperkalemia during 3 of 4 anesthetic events, with ECG changes identified during the second and third events. Serum potassium concentration for both dogs was within the reference range prior to and between anesthetic events. No underlying etiopathogenesis for hyperkalemia was identified for either dog. TREATMENT AND OUTCOME: In each hyperkalemic event, the clinician stopped the dental procedure and continued to provide supportive care and monitoring while the dog recovered from anesthesia. The ECG changes resolved, and serum potassium concentration returned to the reference range rapidly after inhalant anesthetic administration was discontinued. The dogs were discharged from the hospital without further complications. CLINICAL RELEVANCE: Hyperkalemia in anesthetized Greyhounds resulted in serious cardiac conduction abnormalities, which could be potentially fatal if not recognized and promptly treated. Further investigation into the etiopathogenesis, prevention and treatment strategies, and genetic or familial components of this condition is indicated.

Intrapartum Nurse Perception of Labor Support After Implementation of the Coping With Labor Algorithm.

The purpose of this research project was to determine if using the Coping with Labor Algorithm would lead to changes in the perception of the intrapartum (IP) nurses' beliefs toward birth practices and frequency of labor support interventions. Twenty-three participants completed the preintervention survey, which included the IP Nurses' Belief Toward Birth Practice Scale and the Labor Support Scale. Following completion of the preintervention survey, participants received a copy of the Coping with Labor Algorithm and Toolkit and then began implementation of the Coping with Labor Algorithm. After implementation, 13 IP nurses completed the postintervention survey. The surveyed IP nurses reported positive changes in their perceived frequency of labor support and a slight change in their birth beliefs.