JUN mediates the senescence associated secretory phenotype and immune cell recruitment to prevent prostate cancer progression.

BACKGROUND: Prostate cancer develops through malignant transformation of the prostate epithelium in a stepwise, mutation-driven process. Although activator protein-1 transcription factors such as JUN have been implicated as potential oncogenic drivers, the molecular programs contributing to prostate cancer progression are not fully understood. METHODS: We analyzed JUN expression in clinical prostate cancer samples across different stages and investigated its functional role in a Pten-deficient mouse model. We performed histopathological examinations, transcriptomic analyses and explored the senescence-associated secretory phenotype in the tumor microenvironment. RESULTS: Elevated JUN levels characterized early-stage prostate cancer and predicted improved survival in human and murine samples. Immune-phenotyping of Pten-deficient prostates revealed high accumulation of tumor-infiltrating leukocytes, particularly innate immune cells, neutrophils and macrophages as well as high levels of STAT3 activation and IL-1ß production. Jun depletion in a Pten-deficient background prevented immune cell attraction which was accompanied by significant reduction of active STAT3 and IL-1ß and accelerated prostate tumor growth. Comparative transcriptome profiling of prostate epithelial cells revealed a senescence-associated gene signature, upregulation of pro-inflammatory processes involved in immune cell attraction and of chemokines such as IL-1ß, TNF-α, CCL3 and CCL8 in Pten-deficient prostates. Strikingly, JUN depletion reversed both the senescence-associated secretory phenotype and senescence-associated immune cell infiltration but had no impact on cell cycle arrest. As a result, JUN depletion in Pten-deficient prostates interfered with the senescence-associated immune clearance and accelerated tumor growth. CONCLUSIONS: Our results suggest that JUN acts as tumor-suppressor and decelerates the progression of prostate cancer by transcriptional regulation of senescence- and inflammation-associated genes. This study opens avenues for novel treatment strategies that could impede disease progression and improve patient outcomes.

Evaluation of a new extraction platform in combination with molecular assays useful for monitoring immunosuppressed patients.

BACKGROUND: In the immunosuppressed, detection of viral reactivation at the earliest convenience and molecular monitoring are of paramount importance. Nucleic acid extraction has a major impact on the reliability of results obtained from molecular assays. OBJECTIVES: The aim of this study was to investigate the accuracy of the new EMAG® nucleic acid extraction platform and to compare the performance of the new platform to that of the standard NucliSENS® easyMAG® instrument in the routine clinical laboratory. STUDY DESIGN: For accuracy testing, reference material and for comparison studies, clinical specimens were used. In addition, a lab-flow analysis including estimation of hands-on time and that for automated extraction was performed. RESULTS: When accuracy was tested, all 89 results obtained were found to be concordant with the results expected. When 648 clinical results were compared, 85.7% were found to be within ±0.5 log10 unit, 9.5% between ±0.5 and ±1.0 log10 unit, and 4.8% more than ±1.0 log10 unit. The overall time required for nucleic acid extraction of 8 samples in parallel was 94 min for the fully automated extraction mode and 82 min for the partly automated mode with the new platform, and 73 min with the standard instrument. Hands-on time was found to be shorter with the new platform. CONCLUSIONS: The extraction performance of both platforms was found to be similar for EDTA whole blood, BAL, and urine specimens. The total turn-around time for nucleic acid extraction was found to be longer with the EMAG® platform, whereas hands-on time was reduced.