Activation of EGFR signaling pathway leads to prostate cancer bone metastasis; however, therapies targeting EGFR have demonstrated limited effectiveness and led to drug resistance. miR-203 levels are down-regulated in clinical samples of primary prostate cancer and further reduced in metastatic prostate cancer. Here we show that ectopic miR-203 expression displayed reduced bone metastasis and induced sensitivity to tyrosine kinase inhibitors (TKIs) treatment in a xenograft model. Our results demonstrate that the induction of bone metastasis and TKI resistance require miR-203 down-regulation, activation of the EGFR pathway via altered expression of EGFR ligands (EREG and TGFA) and anti-apoptotic proteins (API5, BIRC2, and TRIAP1). Importantly, a sufficient reconstitution of invasiveness and resistance to TKIs treatment was observed in cells transfected with anti-miR-203. In prostate cancer patients, our data showed that miR-203 levels were inversely correlated with the expression of two EGFR ligands, EREG and TGFA, and an EGFR dependent gene signature. Our results support the existence of a miR-203, EGFR, TKIs resistance regulatory network in prostate cancer progression. We propose that the loss of miR-203 is a molecular link in the progression of prostate cancer metastasis and TKIs resistance characterized by high EGFR ligands output and anti-apoptotic proteins activation.
The recurrence of prostate cancer metastases to bone after androgen deprivation therapy is a major clinical challenge. We identified FN14 (TNFRSF12A), a TNF receptor family member, as a factor that promotes prostate cancer bone metastasis. In experimental models, depletion of FN14 inhibited bone metastasis, and FN14 could be functionally reconstituted with IKKβ-dependent, NFκB signaling activation. In human prostate cancer, upregulated FN14 expression was observed in greater than half of metastatic samples. In addition, FN14 expression was correlated inversely with AR signaling output in clinical samples. Consistent with this, AR binding to the FN14 enhancer decreased expression. We show here that FN14 may be a survival factor in low AR output prostate cancer cells. Our results define one upstream mechanism, via FN14 signaling, through which the NFκB pathway contributes to prostate cancer metastasis, and they suggest FN14 as a candidate therapeutic and imaging target for castrate resistant prostate cancers.
Bone metastasis is the hallmark of progressive and castration-resistant prostate cancers. MicroRNA 1 (miR-1) levels are decreased in clinical samples of primary prostate cancer and further reduced in metastases. SRC has been implicated as a critical factor in bone metastasis, and here we show that SRC is a direct target of miR-1. In prostate cancer patient samples, miR-1 levels are inversely correlated with SRC expression and a SRC-dependent gene signature. Ectopic miR-1 expression inhibited extracellular signal-regulated kinase (ERK) signaling and bone metastasis in a xenograft model. In contrast, SRC overexpression was sufficient to reconstitute bone metastasis and ERK signaling in cells expressing high levels of miR-1. Androgen receptor (AR) activity, defined by an AR output signature, is low in a portion of castration-resistant prostate cancer. We show that AR binds to the miR-1-2 regulatory region and regulates miR-1 transcription. Patients with low miR-1 levels displayed correlated low canonical AR gene signatures. Our data support the existence of an AR-miR-1-SRC regulatory network. We propose that loss of miR-1 is one mechanistic link between low canonical AR output and SRC-promoted metastatic phenotypes.
Abstract:Outbreaks of acute oak decline (AOD) have been documented in England from 2006. Both species of native oaks (Quercus robur and Quercus petraea) are affected. To complement isolation efforts for identification of putative causative biotic agents and increase our understanding of bacteria associated with oak tissue, five sites in England were chosen for this study. Samples of outer bark, inner bark, sapwood and heartwood were taken from healthy oak and trees with symptoms at varying stages of the syndrome. Furthermore, larval galleries attributed to infestation with Agrilus biguttatus were included. After DNA extraction and amplification of the V3-V5 fragment of the bacterial 16S rRNA genes by pyrosequencing, the dataset was analyzed to identify patterns in bacterial communities in oak tissue samples with and without AOD symptoms at each site. The composition of bacterial communities differed greatly according to the site from which the samples were obtained. Within each site, the composition of the bacteria associated with symptomatic tissue varied between advanced stages of the syndrome and healthy tissue. Key players in healthy and symptomatic tissue were identified and included members of the Gammaproteobacteria related to Pseudomonas sp. or Brenneria goodwinii and members of the Firmicutes.
We introduce an approach for training Variational Autoencoders (VAEs) that are certifiably robust to adversarial attack. Specifically, we first derive actionable bounds on the minimal size of an input perturbation required to change a VAE's reconstruction by more than an allowed amount, with these bounds depending on certain key parameters such as the Lipschitz constants of the encoder and decoder. We then show how these parameters can be controlled, thereby providing a mechanism to ensure a priori that a VAE will attain a desired level of robustness. Moreover, we extend this to a complete practical approach for training such VAEs to ensure our criteria are met. Critically, our method allows one to specify a desired level of robustness upfront and then train a VAE that is guaranteed to achieve this robustness. We further demonstrate that these Lipschitz-constrained VAEs are more robust to attack than standard VAEs in practice.
<div>Abstract<p>The recurrence of prostate cancer metastases to bone after androgen deprivation therapy is a major clinical challenge. We identified FN14 (TNFRSF12A), a TNF receptor family member, as a factor that promotes prostate cancer bone metastasis. In experimental models, depletion of FN14 inhibited bone metastasis, and FN14 could be functionally reconstituted with IKKβ-dependent, NFκB signaling activation. In human prostate cancer, upregulated FN14 expression was observed in more than half of metastatic samples. In addition, FN14 expression was correlated inversely with androgen receptor (AR) signaling output in clinical samples. Consistent with this, AR binding to the FN14 enhancer decreased expression. We show here that FN14 may be a survival factor in low AR output prostate cancer cells. Our results define one upstream mechanism, via FN14 signaling, through which the NFκB pathway contributes to prostate cancer metastasis and suggest FN14 as a candidate therapeutic and imaging target for castrate-resistant prostate cancers. <i>Cancer Res; 74(16); 4306–17. ©2014 AACR</i>.</p></div>
<p>Supplemental Figure 1.(A) In vitro growth assay for DU145/RasB1 and DU145/RasB1Fn14shRNA cell lines. (B) Average body weight of mice bearing DU145/RasB1 tumors (n= 9mice) or DU145/RasB1Fn14shRNA tumors over time after tumor cell inoculation (shRNA1, n=10 mice; shRNA2, n=10 mice). * p<0.05 vs EV. (C) Average BLI signal in brain metastasis in mice bearing DU145/RasB1/EV, or DU145/RasB1Fn14shRNA tumor at week 4. *** p<0.001 vs control (D) In vitro growth rate of PC3/EV cells and PC3/Fn14shRNA cell lines. (E) Average BLI signal in bone metastasis per mouse in mice bearing PC3/EV tumors or PC3/Fn14shRNA tumors at week 4. Numbers represent mice with bone metastasis over total mice tested. *p<0.05, **p<0.01 vs EV. (F) Survival curve of mice bearing PC3/EV or two PC3/Fn14shRNA cell lines.**p<0.01 vs EV.</p>
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