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Abstract: Fluorescence in situ hybridization analysis for evaluation of 7, 8, X chromosomes and EGFR, LPL, MYC, AR genes in 79 neoplastic foci from 56 patients with clinically localized prostate cancer was performed. We found aneusomy for chromosome 7, 8 and X in 74/77 (96.1%), 56/76 (73.7%), 26/70 (37.1%) of examined foci respectively. No specimen was amplified for EGFR and AR genes, only 2/71 (2.8%) specimens showed MYC gene amplified. LPL deletion was present in 52/76 (68.4%) specimens. Statistically association between Gleason score and both chromosome 7 aneusomy and 8p21 deletion was present. The frequency of chromosome 7 aneusomy was statistically higher in T3-4 cases than T2c and T2a-T2b ones. We considered as unfavorable a genetic set if aneusomy for at least two chromosomes and one altered gene were present. The percentage of tumors, with unfavorable genetic pattern, increased from 36.4 to 75.0% in those with Gleason >7 and from 40.0 to 73.7% in those with stage T3 or more. These alterations could be considered potent genetic markers adjunctive to conventional prognostic parameters. Our objective was to establish specific genetic profiles which may discriminate favorable and unfavorable genetic prognosis tumors. [Copyright &y& Elsevier]

Organ-specific mesenchymal cells naturally reside in the stroma, where they are exposed to some environmental variables affecting their biology and functions. Risk factors such as diabetes or aging influence their adaptive response. In these cases, permanent epigenetic modifications may be introduced in the cells with important consequences on their local homeostatic activity and therapeutic potential. Numerous results suggest that mesenchymal cells, virtually present in every organ, may contribute to tissue regeneration mostly by paracrine mechanisms. Intriguingly, the heart is emerging as a source of different cells, including pericytes, cardiac progenitors, and cardiac fibroblasts. According to phenotypic, functional, and molecular criteria, these should be classified as mesenchymal cells. Not surprisingly, in recent years, the attention on these cells as therapeutic tools has grown exponentially, although only very preliminary data have been obtained in clinical trials to date. In this review, we summarized the state of the art about the phenotypic features, functions, regenerative properties, and clinical applicability of mesenchymal cells, with a particular focus on those of cardiac origin. [ABSTRACT FROM AUTHOR]

Histone deacetylase inhibitors (DIs) are promising drugs for the treatment of several pathologies including ischemic and failing heart where they demonstrated efficacy. However, adverse side effects and cardiotoxicity have also been reported. Remarkably, no information is available about the effect of DIs during tissue regeneration following acute peripheral ischemia. In this study, mice made ischemic by femoral artery excision were injected with the DIs MS275 and MC1568, selective for class I and IIa histone deacetylases (HDACs), respectively. In untreatedmice, soon after damage, class IIa HDAC phosphorylation and nuclear export occurred, paralleled by dystrophin and neuronal nitric-oxide synthase (nNOS) down-regulation and decreased protein phosphatase 2A activity. Between 14 and 21 days after ischemia, dystrophin and nNOS levels recovered, and class IIa HDACs relocalized to the nucleus. In this condition, the MC1568 compound increased the number of newly formedmuscle fibers but delayed their terminal differentiation, whereas MS275 abolished the early onset of the regeneration process determining atrophy and fibrosis. The selective DIs had differential effects on the vascular compartment: MC1568 increased arteriogenesis whereasMS275 inhibited it. Capillaro-genesis did not change. Chromatin immunoprecipitations revealed that class IIaHDAC complexes bind promoters of proliferation-associated genes and of class I HDAC1 and 2, highlighting a hierarchical control between class II and I HDACs during tissue regeneration. Our findings indicate that class-selective DIs interfere with normal mouse ischemic hindlimb regeneration and suggest that their use could be limited by alteration of the regeneration process in peripheral ischemic tissues. [ABSTRACT FROM AUTHOR]

In a mouse model of skin repair we found that the class I-IIa histone deacetylase inhibitor trichostatin A accelerated tissue regeneration. Unexpectedly, this effect was suppressed by Sirtinol, a class III histone deacetylase (HDAC) (sirtuin)-selective inhibitor. The role of sirtuins (SIRTs) was then investigated by using resveratrol and a novel SIRT1-2-3 activator, the MC2562 compound we synthesized recently. Both resveratrol and MC2562 were effective in accelerating wound repair. The local administration of natural or synthetic SIRT activators, in fact, significantly accelerated skin regeneration by increasing keratinocyte proliferation. In vitro experiments revealed that the activation of SIRTs stimulated keratinocyte proliferation via endothelial NO synthase phosphorylation and NO production. In this condition, the class I member HDAC2 was found S-nitrosylated on cysteine, a post-transduction modification associated with loss of activity and DNA binding capacity. After deacetylase inhibitor or SIRT activator treatment, ChIP showed, in fact, a significant HDAC2 detachment from the promoter region of insulin growth factor I (IGF-I), fibroblast growth factor 10 (FGF- 10), and Epithelial Growth Factor (EGF), which may be the final recipients and effectors of the SIRT-NO-HDAC signaling cascade. Consistently, the effect of SIRT activators was reduced in the presence of NG-nitro-L-arginine methyl ester (L-NAME), a general inhibitor of NO synthesis. In conclusion, the NO-dependent cross-talk among class III and I histone deacetylases suggests an unprecedented signaling pathway important for skin repair. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: To confirm our previously obtained results, we genetically characterized prostate cancer from patients undergo radical prostatectomy in a retrospective study. Materials and methods: Histological sections were evaluated for 106 patients treated with surgery from 1991 to 2004. With fluorescence in situ hybridization (FISH) method, the status of LPL (8p22), c-MYC (8q24) genes and 7, 8, X chromosomes was evaluated. Results: Chromosomes 7, 8, X aneusomy was demonstrated in 91.5%, 78.3%, and 51.9% of the samples, respectively, whereas LPL deletion and MYC amplification were found in 76.0% and 1.6%. A genetic profile was considered as unfavorable when at least two aneusomic chromosomes and one altered gene were present. Tumors with an adverse genetic profile were more frequently present in patients with higher stages (P = 0.02), biochemical/clinical progression (P = 0.03), and Gleason grade 4 + 3 (P = 0.02). Multiple correspondence analysis identified one tumor group characterized by chromosome 8 aneusomy, X polysomy, LPL gene deletion, Gleason > 7 and 4 + 3 associated with progression. Conclusions: In this study, we recognized the predictive power of previously identified cytogenetic profiles. Assessment of genetic set may characterize each patient and have influence on postoperative therapeutic strategies. [Copyright &y& Elsevier]

Abstract: The discovery of nitric oxide (NO) revealed its ambiguous nature, which is related to its pleiotropic activities that control the homeostasis of every organism from bacteria to mammals in several physiological and pathological situations. The wide range of action of NO basically depends on two features: 1) the variety of chemical reactions depending on NO, and 2) the differential cellular responses elicited by distinct NO concentrations. Despite the increasing body of knowledge regarding its chemistry, biology and NO-dependent signaling pathways, little information is available on the nuclear actions of NO in terms of gene expression regulation. Indeed, studies of a putative role for this diatomic compound in regulating chromatin remodeling are still in their infancy. Only recently has the role of NO in epigenetics emerged, and some of its putative epigenetic properties are still only hypothetical. In the present review, we discuss the current evidence for NO-related mechanisms of epigenetic gene expression regulation. We link some of the well known NO chemical reactions and metabolic processes (e.g., S-nitrosylation of thiols, tyrosine nitration, cGMP production) to chromatin modification and address the most recent, striking hypothesis about NO and the control of chromosomes structure. [Copyright &y& Elsevier]

Objectives: We evaluated telomerase activity in circulating polymorphonuclear neutrophils (PMN) and in PMN isolated from coronary atherosclerotic plaques by a novel approach. Background: Delayed apoptosis of PMN have been demonstrated in unstable angina (UA). These cells have a finite lifespan with low telomerase activity, a polymerase that extends telomeres, structures essential for cell aging. Reactivation of telomerase has been associated with resistance to apoptosis. Methods: We studied 20 patients with UA and 6 patients with chronic stable angina (SA), undergoing a percutaneous coronary intervention. Circulating PMN were isolated from venous blood and PMN derived from coronary plaque were isolated from washing medium of angioplasty balloons. Results: Telomerase activity was higher in coronary plaque PMN of UA patients than in coronary plaque PMN of SA patients (122.7, range 20.5 to 3,696; and 47.7, range 16 to 212.6, respectively, p = 0.001) and higher than in peripheral PMN of SA patients (122.7, range 20.5 to 3,696 vs. 59, range 16.5 to 132.5, p = 0.001). We found a statistically significant difference between venous and coronary plaque PMN telomerase activity in UA patients (z = −2.875; p = 0.004). Among UA patients, a shorter time interval from symptom onset to coronary PMN sampling was the only independent predictor of high telomerase activity in coronary plaque PMN (p < 0.001, R2 = 0.75). Conclusions: In UA patients, telomerase activity is high in coronary plaque PMN, while it is low in peripheral PMN. Telomerase reactivation in resident PMN resulting in a prolonged lifespan might play a key role in the early phases of instability. [Copyright &y& Elsevier]

Telomere dysfunction contributes to reduced cell viability, altered differentiation, and impaired regenerative/proliferative responses. Recent advances indicate that telomerase activity confers a pro-angiogenic phenotype to endothelial cells and their precursors. We have investigated whether telomerase contributes to tissue regeneration following hind limb ischemia and vascular endothelial growth factor 165 (VEGF165) treatment. VEGF delivery induced angiogenesis and increased expression of the telomerase reverse transcriptase (TERT) and telomerase activity in skeletal muscles and satellite end endothelial cells. Adenovirus-mediated transfer of wild type TERT but not of a dominant negative mutant, TERTdn, significantly induced capillary but not arteriole formation. However, when co-delivered with VEGF, TERTdn abrogated VEGF-dependent angiogenesis, arteriogenesis, and blood flow increase. This effect was paralleled by in vitro evidence that telomerase inhibition by 3′-azido-3′-deoxythymidine in VEGF-treated endothelial cells strongly reduced capillary density and promoted apoptosis in the absence of serum. Similar results were obtained with adenovirus-mediated expression of TERTdn and AKTdn, both reducing endogenous TERT activity and angiogenesis on Matrigel. Mechanistically, neo-angiogenesis in our system involved: (i) VEGF-dependent activation of telomerase through the nitric oxide pathway and (ii) telomerase-dependent activation of endothelial cell differentiation and protection from apoptosis. Furthermore, detection of TERT in activated satellite cells identified them as VEGF targets during muscle regeneration. Because TERT behaves as an angiogenic factor and a downstream effector of VEGF signaling, telomerase activity appears required for VEGF-dependent remodeling of ischemic tissue at the capillaries and arterioles level. [ABSTRACT FROM AUTHOR]

Rescue of embryonic lethality in MDM4-/- mice through concomitant loss of p53 has revealed a functional partnership between the two proteins. Biochemical studies have suggested that MDM4 may act as a negative regulator of p53 levels and activity. On the other hand, MDM4 overexpression has been reported to stabilize p53 levels and to counteract MDM2-degradative activity. We have investigated the functional role of MDM4 overexpression on cell behavior. In both established and primary cells cultured under stress conditions, overexpression of MDM4 significantly increased p53-dependent cell death, in correlation with enhanced induction of the endogenous p53 protein levels. This phenomenon was associated with induced p53 transcriptional activity and increased levels of the proapoptotic protein, Bax. Further, p53 stabilization was accompanied by decreased association of the protein to its negative regulator, MDM2. These findings reveal a novel role for MDM4 by demonstrating that in non-tumor cells under stress conditions it may act as a positive regulator of p53 activity, mainly by controlling p53 levels. They also indicate a major distinction between the biological consequences of MDM4 and MDM2 overexpression. [ABSTRACT FROM AUTHOR]

Prostate cancer (PCa) is a sex-steroid hormone-dependent cancer in which estrogens play a critical role in both initiation and progression. Recently, several long non-coding RNAs (lncRNAs) have been associated with PCa and are supposedly playing a pivotal role in the biology and progression of this type of cancer. In this review, we focused on some lncRNAs that are known for their androgen and estrogen transcriptional responsiveness in PCa. Specifically, we summarized recent pieces of evidence about lncRNAs NEAT1, H19, MALAT1, and HOTAIR, in estrogen signaling, emphasizing their role in PCa progression and the acquisition of a castration-resistant phenotype. Here, the reader will find information about lncRNAs present in estrogen-dependent transcriptional complexes. The potential role of lncRNA/estrogen signaling as a novel pathway for PCa treatment will be discussed. [ABSTRACT FROM AUTHOR]