PO-482 Analysis of small RNA cargo in urinary and plasma EVs and matching prostate cancer and normal prostate tissues

Abstract

adjacent normal tissues. The upregulated NUB1 transcripts were observed in the breast cancer. METABRIC cohort highlighted that patients with low NUB1 transcripts had a poorer survival in the ER-negative subgroup of breast cancer patients [hazard ratio (HR)=0.66, 95% confidence interval (CI)=0. 5-0.87, p=0.003] and triple negative subgroup (HR=0.67, 95% CI=0. 47-0.96, p=0.028). NUB1 knockdown inhibits in vitro cell growth in MDA-MB-231. AIPL1 protein forms multimers in cancer cells. NUB1 protein moved into the nucleus in hypoxia (0.1% O 2 48 hours). p21 and p27 proteins accumulated in NUB1-knockdown MDA-MB-231 cells. The prolonged G 0 /G 1 cell cycle arrests resulted in cell death through the neddylation-dependent CUL1-p27-p21 and CUL2-VHL axis. We also demonstrated that HIF1a protein could be neddylated upon reoxygenation. In a retrospective study of Oxford breast cancer cohort, the lower cytoplasmic expression (n=57) prognosed worse overall survival than higher cytoplasmic expression (n=57) (HR=1.779, 95% CI=1. 006-3.346, p=0.048 Introduction Sarcomas often show a limited response to current treatments. A hypothesis to explain this resistance relies on the existence of subpopulations of drug-resistant cancer stem cells (CSCs) responsible for relapses and metastasis. Therefore, there is a need for patient-close disease models amenable for testing the effect of anti-cancer therapies on CSCs. As a proof-of principle of their possible utility in future personalise medicine strategies, we have established a panel of patient-derived sarcoma primary cell lines, characterised their CSC subpopulations and tested the anti-tumour activity of the mithramycin analogue EC-8042 on these cell lines. Material and methods Fresh surgical samples of sarcomas were disaggregated and put in culture. In those cell lines adapted to grow in vitro, their proliferation ability and their potential to growth tumour xenografts were evaluated. CSCs subpopulations were characterised according to their ability to grow as tumorspheres, and the presence of cells presenting ALDH1 activity (Aldefluor © activity) or transcriptional activity due to SOX2/OCT4 in cells expressing the reporter system Sore6 (Sore6 activity). Cell survival, apoptotic induction and modulation of Sore6 activity was analysed after drug treatments. Finally, the expression/phosphorylation of signalling proteins was analysed by Western blotting. Results and discussions We have established a panel of patientderived primary cell lines able to reproduce in vivo the histopathological features of their tumours of origin. Most of these cell lines were able to grow as serially passaged tumorspheres and showed between 1% and 15% of Aldefluor © positive cells. In addition, we detected Sore6 activity in 25% of cells in a cell line expressing the Sore6 reporter. Finally, these cell lines showed a distinct sensitivity to EC8042, with IC 50 values ranging from 0.1 to 1 mM. EC-8042 was able to inhibit the expression of CSC-related factors such as SOX2, NOTCH1 and C-MYC in a dose-dependent fa...

Extracellular Vesicles as Biomarkers in Cancer Immunotherapy

“…Furthermore, it appears to be accurate in longitudinal monitoring of treatment response. A number of other studies have indicated that specific mRNA species show differential expression in responsive and unresponsive patients receiving immunotherapy [ 128 , 129 , 130 ]. Liu et al evaluated the prognostic and predictive value of serum EV-associated miRNAs for tumor recurrence and response to therapy in colon cancer.…”