The transcription factor E-twenty-six related gene (ERG), which is overexpressed through gene fusion with the androgen-responsive gene transmembrane protease, serine 2 (TMPRSS2) in ∼40% of prostate tumors, is a key driver of prostate carcinogenesis. Ablation of ERG would disrupt a key oncogenic transcriptional circuit and could be a promising therapeutic strategy for prostate cancer treatment. Here, we show that ubiquitin-specific peptidase 9, X-linked (USP9X), a deubiquitinase enzyme, binds ERG in VCaP prostate cancer cells expressing TMPRSS2-ERG and deubiquitinates ERG in vitro. USP9X knockdown resulted in increased levels of ubiquitinated ERG and was coupled with depletion of ERG. Treatment with the USP9X inhibitor WP1130 resulted in ERG degradation both in vivo and in vitro, impaired the expression of genes enriched in ERG and prostate cancer relevant gene signatures in microarray analyses, and inhibited growth of ERG-positive tumors in three mouse xenograft models. Thus, we identified USP9X as a potential therapeutic target in prostate cancer cells and established WP1130 as a lead compound for the development of ERGdepleting drugs. P rostate cancer is the most common malignancy in men and the second or third leading cause of male cancer-related death in most Western countries, including the United States (1). Advanced prostate cancer initially responds to androgen ablation therapy, but hormone-refractory prostate cancer often times recurs, which has limited treatment options. Fusions of E-twentysix (ETS) transcription factor genes with androgen-responsive genes (2), mainly transmembrane protease, serine 2 (TMPRSS2), are present in up to 80% of prostate cancers. Patients with the most common ETS gene fusion TMPRSS2-ETS related gene (TMPRSS2-ERG) have a higher incidence of metastatic disease and cancer-related death compared with fusion-negative patients (3, 4), and in castration-resistant prostate cancer, TMPRSS2-ERG expression is frequently reactivated (5). In support of ERG being a key driver of prostate cancer, depletion of ERG by RNAi decreases proliferation and/or invasiveness in prostate cancer cell lines (2, 6), and ectopic expression of ERG in transgenic mice was shown to promote prostate oncogenesis in cooperation with the loss of tumor suppressors (7-12). TMPRSS2-driven overexpression of ERG controls a transcriptional network related to the development of prostate cancer and its progression to metastatic disease (13,14). This crucial role of ERG and the high incidence of the TMPRSS2-ERG gene fusion in prostate cancer have catapulted this protein into the forefront of new targets for therapeutic intervention (3,8). In the present study, we report the discovery of a deubiquitinase that stabilizes ERG in prostate cancer cells and demonstrate that pharmacological inhibition of this enzyme causes ERG depletion. Results USP9X is an ERG-Binding Protein.Proteins that interact with ERG in prostate cancer cells may modulate its activity, localization, or stability and could be harnessed as therapeutic target...

IFNg, a potent cytokine known to modulate tumor immunity and tumoricidal effects, is highly elevated in patients with prostate cancer after radiation. In this study, we demonstrate that IFNg can induce epithelial-to-mesenchymal transition (EMT) in prostate cancer cells via the JAK-STAT signaling pathway, leading to the transcription of IFN-stimulated genes (ISG) such as IFN-induced tetratricopeptide repeat 5 (IFIT5). We unveil a new function of IFIT5 complex in degrading precursor miRNAs (pre-miRNA) that includes pre-miR-363 from the miR-106a-363 cluster as well as pre-miR-101 and pre-miR-128, who share a similar 5 0 -end structure with pre-miR-363. These suppressive miRNAs exerted a similar function by targeting EMT transcription factors in prostate cancer cells. Depletion of IFIT5 decreased IFNg-induced cell invasiveness in vitro and lung metastasis in vivo. IFIT5 was highly elevated in high-grade prostate cancer and its expression inversely correlated with these suppressive miRNAs. Altogether, this study unveils a prometastatic role of the IFNg pathway via a new mechanism of action, which raises concerns about its clinical application.Significance: A unique IFIT5-XRN1 complex involved in the turnover of specific tumor suppressive microRNAs is the underlying mechanism of IFNg-induced epithelial-tomesenchymal transition in prostate cancer.See related commentary by Liu and Gao, p. 1032

With more and more engineered nanoparticles (NPs) being designed renal clearable for clinical translation, fundamental understandings of their transport in the different compartments of kidneys become increasingly important. Here, we report noninvasive X-ray imaging of renal clearable gold NPs (AuNPs) in normal and nephropathic kidneys. By quantifying the transport kinetics of the AuNPs in cortex, medulla and pelvis of the normal and injured kidneys, we found that ureteral obstruction not just blocked the NP elimination through the ureter but also slowed down their transport from the medulla to pelvis and enhanced the cellular uptake. Moreover, the transport kinetics of the NPs and renal anatomic details can be precisely correlated with local pathological lesion. These findings not only advance our understandings of nano-bio interactions in the kidneys but offer a new pathway to noninvasively image kidney dysfunction and local injuries at the anatomical level.

Acetaldehyde (Ac), the main metabolite of ethanol oxidation, is a very reactive compound involved in alcohol-induced liver damage. In the present work, we studied the effect of Ac in mitochondria functionality. Mitochondria from Wistar rats were isolated and treated with Ac. Ac decreased respiratory control by 50% which was associated with a decrease in adenosine triphosphate content (28.5%). These results suggested that Ac could be inducing changes in cell redox status. We determined protein oxidation, superoxide dismutase (SOD) activity, and glutathione ratio, indicating that Ac induced an enhanced oxidation of proteins and a decrease in SOD activity (90%) and glutathione/oxidized GSH ratio (36%). The data suggested that Ac-induced oxidative stress mediated by mitochondria dysfunction can lead to cell sensitization and to a second oxidative challenge. We pretreated hepatocytes with Ac followed by treatment with antimycin A, and this experiment revealed a noticeable decrease in cell viability, determined by neutral red assay, in comparison with cells treated with Ac alone. Our data demonstrate that Ac impairs mitochondria functionality generating oxidative stress that sensitizes cells to a second damaging signal contributing to the development of alcoholic liver disease.

Objective To explore incidence and progression of coronary atherosclerosis and identify determinants in patients with rheumatoid arthritis (RA). We specifically evaluated the impact of inflammation, cardiac risk factors, duration of medication exposure, and their interactions on coronary plaque progression. Methods One hundred one participants with baseline coronary computed tomography angiography findings underwent follow‐up assessment a mean ± SD of 83 ± 3.6 months after baseline. Plaque burden was reported as the segment involvement score (describing the number of coronary segments with plaque) and the segment stenosis score (characterizing the cumulative plaque stenosis over all evaluable segments). Plaque composition was classified as noncalcified, mixed, or calcified. Coronary artery calcium (CAC) was quantified using the Agatston method. Results Total plaque increased in 48% of patients, and progression was predicted by older age, higher cumulative inflammation, and total prednisone dose (P < 0.05). CAC progressors were older, more obese, hypertensive, and had higher cumulative inflammation compared to nonprogressors (P < 0.05). Longer exposure to biologics was associated with lower likelihood of noncalcified plaque progression, lesion remodeling, and constrained CAC change in patients without baseline calcification, independent of inflammation, prednisone dose, or statin exposure (all P < 0.05). Longer statin treatment further restricted noncalcified plaque progression and attenuated the effect of inflammation on increased plaque and CAC (P < 0.05). Stringent systolic blood pressure (BP) control further weakened the effect of inflammation on total plaque progression. Conclusion Inflammation was a consistent and independent predictor of coronary atherosclerosis progression in RA. It should therefore be specifically targeted toward mitigating cardiovascular risk. Biologic disease‐modifying antirheumatic drugs, statins, and BP control may further constrain plaque progression directly or indirectly.

Purpose Clinical evidence suggests an increased CSC in tumor mass may contribute to the failure of conventional therapies since CSCs seem to be more resistant than differentiated tumor cells. Thus, unveiling the mechanism regulating CSCs and candidate target molecules will provide new strategy to cure the patients. Experimental design The stem-like cell properties were determined by a prostasphere assay, and dye exclusion assay. To find critical stem cell marker and reveal regulation mechanism, basic biochemical and molecular biological methods such as qRT-PCR, Western blot, reporter gene assay and chromatin immunoprecipitation assay were employed. In addition, to determine the effect of combination therapy targeting both CSCs and its progeny, in vitro MTT assay and in vivo xenograft model was used. Results We demonstrate immortalized normal human prostate epithelial cells, appeared non-tumorigenic in vivo, become tumorigenic and acquire stem cell phenotype after knocking down a tumor suppressor gene. Also, those stem-like cells increase chemoresistance to conventional anti-cancer reagent. Mechanistically, we unveil that Wnt signaling is a key pathway regulating well-known stem cell marker CD44 by directly interacting to the promoter. Thus, by targeting CSCs using Wnt inhibitors synergistically enhances the efficacy of conventional drugs. Furthermore, the in vivo mice model bearing xenografts showed a robust inhibition of tumor growth after combination therapy. Conclusions Overall, this study provides strong evidence of CSC in CRPC. This new combination therapy strategy targeting CSC could significantly enhance therapeutic efficacy of current chemotherapy regimen only targeting non-CSC cells.

Hepatocyte growth factor (HGF) is involved in many cellular responses, such as mitogenesis and apoptosis protection; however, its effect against oxidative injury induced by ethanol metabolism is not well understood. The aim of this work was to address the mechanism of HGF-induced protection against ethanol-generated oxidative stress damage in the human cell line VL-17A (cytochrome P450 2E1/alcohol dehydrogenase-transfected HepG2 cells). Cells were pretreated with 50 ng/ml HGF for 12 h and then treated with 100 mM ethanol for 0-48 h. Some parameters of oxidative damage were evaluated. We found that ethanol induced peroxide formation (3.3-fold) and oxidative damage as judged by lipid peroxidation (5.4-fold). Damage was prevented by HGF. To address the mechanisms of HGF-induced protection we investigated the cellular antioxidant system. We found that HGF increased the GSH/GSSG ratio, as well as SOD1, catalase, and gamma-glutamylcysteine synthetase expression. To explore the signaling pathways involved in this process, VL-17A cells were pretreated with inhibitors against PI3K, Akt, and NF-kappaB. We found that all treatments decreased the expression of the antioxidant enzymes, thus abrogating the HGF-induced protection against oxidative stress. Our results demonstrate that HGF protects cells from the oxidative damage induced by ethanol metabolism by a mechanism driven by NF-kappaB and PI3K/Akt signaling.

Cancer stem cell (CSC), the primary source of cancer-initiating population, is involved in cancer recurrence and drug-resistant phenotypes. This study demonstrates that the loss of DAB2IP, a novel Ras-GTPase activating protein frequently found in many cancer types, is associated with CSC properties. Mechanistically, DAB2IP is able to suppress stem cell factor receptor (c-kit or CD117) gene expression by interacting with a newly identified silencer in the c-kit gene. Moreover, DAB2IP is able to inhibit c-kit-PI3K-Akt-mTOR signaling pathway that increases c-myc protein to activate ZEB1 gene expression leading to the elevated CSC phenotypes. An inverse correlation between CD117 or ZEB1 and DAB2IP is also found in clinical specimens. Similarly, Elevated expression of ZEB1 and CD117 are found in the prostate basal cell population of DAB2IP knockout mice. Our study reveals that DAB2IP has a critical role in modulating CSC properties via CD117-mediated ZEB1 signaling pathway.