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Estrogen-dependent dynamic profile of eNOS-DNA associations in prostate cancer.

Nanni S, Aiello A, Re A, Guffanti A, Benvenuti V, Colussi C, Castro-Vega LJ, Felsani A, Londono-Vallejo A, Capogrossi MC, Bacchetti S, Gaetano C, Pontecorvi A, Farsetti A - PLoS ONE (2013)

Bottom Line: To explore the role of nuclear eNOS in the acquisition of aggressive phenotype in PCa, we performed ChIP-Sequencing on chromatin-associated eNOS from cells from a primary tumor with poor outcome and from metastatic LNCaP cells.The parallel finding of downregulation of a cluster of miRs, including miR-34a, in PCa cells associated with poor outcome led us to unveil a molecular link between eNOS and SIRT1, an epigenetic regulator of aging and tumorigenicity, negatively regulated by miR-34a and in turn activating eNOS.E2 potentiates miR-34a downregulation thus enhancing SIRT1 expression, depicting a novel eNOS/SIRT1 interplay fine-tuned by E2-activated ER signaling, and suggesting that eNOS may play an important role in aggressive PCa.

View Article: PubMed Central - PubMed

Affiliation: Department of Experimental Oncology, National Cancer Institute Regina Elena, Rome, Italy.

ABSTRACT
In previous work we have documented the nuclear translocation of endothelial NOS (eNOS) and its participation in combinatorial complexes with Estrogen Receptor Beta (ERβ) and Hypoxia Inducible Factors (HIFs) that determine localized chromatin remodeling in response to estrogen (E2) and hypoxia stimuli, resulting in transcriptional regulation of genes associated with adverse prognosis in prostate cancer (PCa). To explore the role of nuclear eNOS in the acquisition of aggressive phenotype in PCa, we performed ChIP-Sequencing on chromatin-associated eNOS from cells from a primary tumor with poor outcome and from metastatic LNCaP cells. We found that: 1. the eNOS-bound regions (peaks) are widely distributed across the genome encompassing multiple transcription factors binding sites, including Estrogen Response Elements. 2. E2 increased the number of peaks, indicating hormone-dependent eNOS re-localization. 3. Peak distribution was similar with/without E2 with ≈ 55% of them in extragenic DNA regions and an intriguing involvement of the 5' domain of several miRs deregulated in PCa. Numerous potentially novel eNOS-targeted genes have been identified suggesting that eNOS participates in the regulation of large gene sets. The parallel finding of downregulation of a cluster of miRs, including miR-34a, in PCa cells associated with poor outcome led us to unveil a molecular link between eNOS and SIRT1, an epigenetic regulator of aging and tumorigenicity, negatively regulated by miR-34a and in turn activating eNOS. E2 potentiates miR-34a downregulation thus enhancing SIRT1 expression, depicting a novel eNOS/SIRT1 interplay fine-tuned by E2-activated ER signaling, and suggesting that eNOS may play an important role in aggressive PCa.

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Cartoon of proposed eNOS/SIRT1 interplay in prostate cancer cells in response to estrogen.
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pone-0062522-g006: Cartoon of proposed eNOS/SIRT1 interplay in prostate cancer cells in response to estrogen.

Mentions: Based on our results we propose the following model: in aggressive PCa an abnormal estrogen stimulation, resulting from the decrease of androgen in favor of estrogen during aging [52], results in almost complete silencing of miR-34a. As a consequence, there is a rapid increase in SIRT1 expression that determines, in turn, activation of eNOS. The resulting positive feedback on both proteins (see cartoon in Figure 6) further represses transcription of miR34-a. Silencing of this miR has already been linked to promotion of prostate cancer stem cells and metastasis [35]. Our contribution reveals the molecular mechanisms responsible for this phenomenon, i.e. its dependence on the transcriptional repressive function of eNOS-containing complexes. Genetic inhibition of eNOS by overexpression of a dominant negative eNOS mutant, interrupts the eNOS/miR-34a/SIRT1 pathway, thus validating our hypothesis (Figure 5B,C).


Estrogen-dependent dynamic profile of eNOS-DNA associations in prostate cancer.

Nanni S, Aiello A, Re A, Guffanti A, Benvenuti V, Colussi C, Castro-Vega LJ, Felsani A, Londono-Vallejo A, Capogrossi MC, Bacchetti S, Gaetano C, Pontecorvi A, Farsetti A - PLoS ONE (2013)

Cartoon of proposed eNOS/SIRT1 interplay in prostate cancer cells in response to estrogen.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3643940&req=5

pone-0062522-g006: Cartoon of proposed eNOS/SIRT1 interplay in prostate cancer cells in response to estrogen.
Mentions: Based on our results we propose the following model: in aggressive PCa an abnormal estrogen stimulation, resulting from the decrease of androgen in favor of estrogen during aging [52], results in almost complete silencing of miR-34a. As a consequence, there is a rapid increase in SIRT1 expression that determines, in turn, activation of eNOS. The resulting positive feedback on both proteins (see cartoon in Figure 6) further represses transcription of miR34-a. Silencing of this miR has already been linked to promotion of prostate cancer stem cells and metastasis [35]. Our contribution reveals the molecular mechanisms responsible for this phenomenon, i.e. its dependence on the transcriptional repressive function of eNOS-containing complexes. Genetic inhibition of eNOS by overexpression of a dominant negative eNOS mutant, interrupts the eNOS/miR-34a/SIRT1 pathway, thus validating our hypothesis (Figure 5B,C).

Bottom Line: To explore the role of nuclear eNOS in the acquisition of aggressive phenotype in PCa, we performed ChIP-Sequencing on chromatin-associated eNOS from cells from a primary tumor with poor outcome and from metastatic LNCaP cells.The parallel finding of downregulation of a cluster of miRs, including miR-34a, in PCa cells associated with poor outcome led us to unveil a molecular link between eNOS and SIRT1, an epigenetic regulator of aging and tumorigenicity, negatively regulated by miR-34a and in turn activating eNOS.E2 potentiates miR-34a downregulation thus enhancing SIRT1 expression, depicting a novel eNOS/SIRT1 interplay fine-tuned by E2-activated ER signaling, and suggesting that eNOS may play an important role in aggressive PCa.

View Article: PubMed Central - PubMed

Affiliation: Department of Experimental Oncology, National Cancer Institute Regina Elena, Rome, Italy.

ABSTRACT
In previous work we have documented the nuclear translocation of endothelial NOS (eNOS) and its participation in combinatorial complexes with Estrogen Receptor Beta (ERβ) and Hypoxia Inducible Factors (HIFs) that determine localized chromatin remodeling in response to estrogen (E2) and hypoxia stimuli, resulting in transcriptional regulation of genes associated with adverse prognosis in prostate cancer (PCa). To explore the role of nuclear eNOS in the acquisition of aggressive phenotype in PCa, we performed ChIP-Sequencing on chromatin-associated eNOS from cells from a primary tumor with poor outcome and from metastatic LNCaP cells. We found that: 1. the eNOS-bound regions (peaks) are widely distributed across the genome encompassing multiple transcription factors binding sites, including Estrogen Response Elements. 2. E2 increased the number of peaks, indicating hormone-dependent eNOS re-localization. 3. Peak distribution was similar with/without E2 with ≈ 55% of them in extragenic DNA regions and an intriguing involvement of the 5' domain of several miRs deregulated in PCa. Numerous potentially novel eNOS-targeted genes have been identified suggesting that eNOS participates in the regulation of large gene sets. The parallel finding of downregulation of a cluster of miRs, including miR-34a, in PCa cells associated with poor outcome led us to unveil a molecular link between eNOS and SIRT1, an epigenetic regulator of aging and tumorigenicity, negatively regulated by miR-34a and in turn activating eNOS. E2 potentiates miR-34a downregulation thus enhancing SIRT1 expression, depicting a novel eNOS/SIRT1 interplay fine-tuned by E2-activated ER signaling, and suggesting that eNOS may play an important role in aggressive PCa.

Show MeSH
Related in: MedlinePlus