ABSTRACT
Recent evidence has implicated the transmembrane co-receptor neuropilin-1 (NRP1) in cancer progression. Primarily known as a regulator of neuronal guidance and angiogenesis, NRP1 is also expressed in multiple human malignancies, where it promotes tumor angiogenesis. However, non-angiogenic roles of NRP1 in tumor progression remain poorly characterized. In this study, we define NRP1 as an androgen-repressed gene whose expression is elevated during the adaptation of prostate tumors to androgen-targeted therapies (ATTs), and subsequent progression to metastatic castration-resistant prostate cancer (mCRPC). Using short hairpin RNA (shRNA)-mediated suppression of NRP1, we demonstrate that NRP1 regulates the mesenchymal phenotype of mCRPC cell models and the invasive and metastatic dissemination of tumor cells in vivo. In patients, immunohistochemical staining of tissue microarrays and mRNA expression analyses revealed a positive association between NRP1 expression and increasing Gleason grade, pathological T score, positive lymph node status and primary therapy failure. Furthermore, multivariate analysis of several large clinical prostate cancer (PCa) cohorts identified NRP1 expression at radical prostatectomy as an independent prognostic biomarker of biochemical recurrence after radiation therapy, metastasis and cancer-specific mortality. This study identifies NRP1 for the first time as a novel androgen-suppressed gene upregulated during the adaptive response of prostate tumors to ATTs and a prognostic biomarker of clinical metastasis and lethal PCa.
Subject(s)
Neuropilin-1/genetics , Neuropilin-1/metabolism , Prostatic Neoplasms, Castration-Resistant/mortality , Prostatic Neoplasms/drug therapy , Up-Regulation , Androgen Antagonists/therapeutic use , Cell Line, Tumor , Disease Progression , Epithelial-Mesenchymal Transition , Gene Expression Regulation, Neoplastic/drug effects , Humans , Male , Neoplasm Grading , Neoplasm Metastasis , Prostatic Neoplasms/genetics , Prostatic Neoplasms/mortality , Survival AnalysisABSTRACT
BACKGROUND: There is an acute need to uncover biomarkers that reflect the molecular pathologies, underpinning prostate cancer progression and poor patient outcome. We have previously demonstrated that in prostate cancer cell lines PDE4D7 is downregulated in advanced cases of the disease. To investigate further the prognostic power of PDE4D7 expression during prostate cancer progression and assess how downregulation of this PDE isoform may affect disease outcome, we have examined PDE4D7 expression in physiologically relevant primary human samples. METHODS: About 1405 patient samples across 8 publically available qPCR, Affymetrix Exon 1.0 ST arrays and RNA sequencing data sets were screened for PDE4D7 expression. The TMPRSS2-ERG gene rearrangement status of patient samples was determined by transformation of the exon array and RNA seq expression data to robust z-scores followed by the application of a threshold>3 to define a positive TMPRSS2-ERG gene fusion event in a tumour sample. RESULTS: We demonstrate that PDE4D7 expression positively correlates with primary tumour development. We also show a positive association with the highly prostate cancer-specific gene rearrangement between TMPRSS2 and the ETS transcription factor family member ERG. In addition, we find that in primary TMPRSS2-ERG-positive tumours PDE4D7 expression is significantly positively correlated with low-grade disease and a reduced likelihood of progression after primary treatment. Conversely, PDE4D7 transcript levels become significantly decreased in castration resistant prostate cancer (CRPC). CONCLUSIONS: We further characterise and add physiological relevance to PDE4D7 as a novel marker that is associated with the development and progression of prostate tumours. We propose that the assessment of PDE4D7 levels may provide a novel, independent predictor of post-surgical disease progression.
Subject(s)
Cyclic Nucleotide Phosphodiesterases, Type 4/genetics , Oncogene Proteins, Fusion/genetics , Prostatic Neoplasms/enzymology , Prostatic Neoplasms/surgery , Disease Progression , Down-Regulation , Humans , Male , Prostatic Neoplasms/genetics , Prostatic Neoplasms/pathology , Prostatic Neoplasms, Castration-Resistant/genetics , Sequence Analysis, RNAABSTRACT
This paper describes a study of the impact of Physician Order Entry (POE) on pharmacy order turn-around times. The study looked at two surgical services, Neurosurgery and Transplant, of a large Midwestern academic medical center. Pharmacy orders were followed in these units from the time a physician wrote an order to the time the patient received the medication. The first part of the study tracked pharmacy orders for a two-month period before the implementation of POE and the second part of the study tracked pharmacy orders for a two-month period after POE had been implemented. The pre- and post-POE pharmacy turn-around times were compared. It was expected that the data would show a substantial decrease in pharmacy order turn-around times. Our study did, in fact, show a significant reduction in this turn-around-time.