Malignant canine mammary epithelial cells shed exosomes containing differentially expressed microRNA that regulate oncogenic networks

Abstract Background Breast (mammary) cancers in human (BC) and canine (CMT) patients share clinical, pathological, and molecular similarities that suggest dogs may be a useful translational model. Many cancers, including BC, shed exosomes that contain microRNAs (miRs) into the microenvironment and circulation, and these may represent biomarkers of metastasis and tumor phenotype. Methods Three normal canine mammary epithelial cell (CMEC) cultures and 5 CMT cell lines were grown in serum-free media. Exosomes were isolated from culture media by ultracentrifugation then profiled by transmission electron microscopy, dynamic light scattering, and Western blot. Exosomal small RNA was deep-sequenced on an Illumina HiSeq2500 sequencer and validated by qRT-PCR. In silico bioinformatic analysis was carried out to determine microRNA gene and pathway targets. Results CMEC and CMT cell lines shed round, “cup-shaped” exosomes approximately 150–200 nm, and were immunopositive for exosomal marker CD9. Deep-sequencing averaged ~ 15 million reads/sample. Three hundred thirty-eight unique miRs were detected, with 145 having > ±1.5-fold difference between one or more CMT and CMEC samples. Gene ontology analysis revealed that the upregulated miRs in this exosomal population regulate a number of relevant oncogenic networks. Several miRNAs including miR-18a, miR-19a and miR-181a were predicted in silico to target the canine estrogen receptor (ESR1α). Conclusions CMEC and CMT cells shed exosomes in vitro that contain differentially expressed miRs. CMT exosomal RNA expresses a limited number of miRs that are up-regulated relative to CMEC, and these are predicted to target biologically relevant hormone receptors and oncogenic pathways. These results may inform future studies of circulating exosomes and the utility of miRs as biomarkers of breast cancer in women and dogs

How do doctors refer to patient-reported outcome measures (PROMS) in oncology consultations?

Purpose We conducted a secondary qualitative analysis of consultations between oncologists and their patients to explore how patient-reported outcome measures (PROMs) data were referred to in the process of (1) eliciting and exploring patients’ concerns; (2) making decisions about supportive treatment and (3) making decisions about chemotherapy and other systemic treatments. Methods We purposively sampled audio recordings of 18 consultations from the intervention arm and 4 from the attention control arm of a previous UK randomised controlled trial of the feedback of PROMs data to doctors (Velikova et al. in J Clin Oncol 22(4):714–724 [1]). We used a combination of content and conversation analysis to examine how opportunities for discussion of health-related quality of life issues are opened up or closed down within the consultation and explore why this may or may not lead to changes in patient management. Findings Explicit reference to the PROMs data provided an opportunity for the patient to clarify and further elaborate on the side effects of chemotherapy. High scores on the PROMs data were not explored further if the patient indicated they were not a problem or were not related to the cancer or chemotherapy. Symptomatic treatment was more often offered for problems like nausea, constipation, pain and depression but much less so for fatigue. Doctors discussed fatigue by providing a cause for the fatigue (e.g. the chemotherapy), presenting this as ‘something to be expected’, minimising its impact or moving on to another topic. Chemotherapy regimens were not changed on the basis of the PROMs data alone, but PROMs data were sometimes used to legitimise changes. Conclusions Explicit mention of PROMs data in the consultation may strengthen opportunities for patients to elaborate on their problems, but doctors may not always know how to do this. Our findings have informed the development of a training package to enable doctors to optimise their use of PROMs data within the consultation