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Background: Phosphatidylinositol 3-kinase (PI3K) is necessary for insulin action on glucose and lipid metabolism. In epithelial cells, which do not express GLUT4 and gluconeogenic enzymes, insulin mediated PI3K activation regulates cell survival, growth, proliferation and motility. Although the involvement of p85αregulatory subunit of PI3K (p85αPI3K) in insulin signal transduction has been extensively studied, the function of the N-terminus of p85αPI3K remains elusive. A serine at codon 83 (S83) in the p85αPI3K that is phosphorylated by protein kinase A (PKA) invivo and in vitrohas been identified. Methods: To determine the molecular mechanism linking PKA to insulin mediated PI3K activation in MCF7 cells, we used p85αPI3K mutated forms, in which S83 has been substituted with alanine (p85A) to prevent phosphorylation or with aspartic acid (p85D) to mimic the phosphorylated residue. Results: We demonstrated that phosphorylation of p85αPI3KS83 modulates the formation of the p85αPI3K/IRS1 complex and its subcellular localization influencing the kinetics of the insulin signaling both on MAPK-ERK and AKT pathways. Growth curves and cell cycle analysis demonstrated that phosphorylation of p85αPI3KS83 plays a central role in the control of insulin mediated cell proliferation. Conclusions:In conclusion, the insulin-modulated plating efficiency and cell migration were markedly influenced by the expression of the p85αPI3KS83 mutants.

Adiponectin (Acrp30) is an adipocyte-secreted hormone with pleiotropic metabolic effects, whose reduced levels were related to development and progression of several malignancies. We looked at the presence of Acrp30 receptors in human glioblastomas (GBM), hypothesizing a role for Acrp30 also in this untreatable cancer. Here we demonstrate that human GBM express Acrp30 receptors (AdipoR1 and AdipoR2), which are often co-expressed in GBM samples (70% of the analyzed tumors). To investigate the effects of Acrp30 on GBM growth, we used human GBM cell lines U87-MG and U251, expressing both AdipoR1 and AdipoR2 receptors. In these cells, Acrp30 treatment inhibits DNA synthesis and cell proliferation rate, inducing arrest in G1 phase of the cell cycle. These effects were correlated to a sustained activation of ERK1/2 and Akt kinases, upon Acrp30 treatment. Our results suggest that Acrp30 may represent a novel endogenous negative regulator of GBM cell proliferation, to be evaluated for the possible development of novel pharmacological approaches. © 2014 Wiley Periodicals, Inc.

NTP1 Background: The dynamic intra- and inter-chromosomal links between specific loci contribute to the creation of cell type-specific gene expression profiles and to gene regulation during differentiation processes. Looping is implicated in bringing together far upstream or downstream regions with the gene promoter and body sites, and in establishing contacts between the 5' and 3' ends of genes, since 3' end-processing factors interact with components of the transcriptional machinery. The tumor suppressor PRDM2/RIZ gene plays a role in controlling cellular processes, such as cell cycle progression and regulation of development. The retinoblastoma proteinineracting zinc-finger gene (RIZ) is estrogen responsive and has two alternative promoters, the more downstream of which, promoter 2, is nearby to an EREsequence and is involved in estrogen receptor transcriptional activation. Methods: With the innovative DNA-Picked Chromatin (DPC) assay after timecourse of 17-ßestradiol (E2) induction of MCF-7 breast cancer cells, we highlight preferential interaction between hormone-responsive RIZ promoter and the polyadenylation sites. Gene expression analysis of induced cell RNA was performed with qRT-PCR assay. Results: Within 60’ of E2 treatment of cells, we have observed increased exon segments, exons 9a and 10 (alternative polyA site), linked to isolated promoter 2 and concomitant decrease of exon10 to RIZ promoter 1. The exon 9a shows a low association to RIZ promoter 1 without E2. qRT-PCR also demonstrated increased exon 9a-containing transcripts. Conclusions: The E2 remodels the chromatin architecture of PRDM2/RIZ gene locus to create a loop for the mRNA transcription with polyA-exon 9a, leading to the production of oncogenic variants.

ST2. PRDM Gene Products in Testicular Germ Cell Tumors E. di Zazzo1, C. Porcile1, C. De Rosa2, A. Marino1, S. Bartollino1, C. Abbondanza2, B. Moncharmont1 1Università degli Studi del Molise, Campobasso, Italy; 2Seconda Università degli studi di Napoli, Naples, Italy Background: Testicular germ cell tumors (TGCT) originate from primordial germ cells blocked at different stages during maturation, reflecting different histological tumor subtypes. A common genetic alteration in TGCT is a deletion of chromosome 1 short arm, where the PRDM2 gene, a member of positive regulatory domain gene family, is located. Moreover recent studies demonstrated that members of PRDM gene family have an essential role in the early stages of testicular development. The aim of this study is to evaluate PRDM gene family members for a possible tumorsuppressor function in TGCT. Methods: PRDM gene expression was assessed by mRNA RT-PCR. Cells were treated with 100 nM 17β-Estradiol (E2), 100 nM DHT or 10 uM RA in serum free medium for 24h. RNA interference was performed using BLOCK-iT™ Pol II miR RNAi system. Proliferation assay was performed with propidium iodide staining and FACS analysis. Results: In GC1 mouse spermatogonial cells treatment with proliferation agents 5α-dihydrotestosterone (DHT) and E2 reduced PRDM2/RIZ1 expression levels whereas PRDM2 total forms showed no variation; the same treatment significantly increased PRDM4 and PRDM10 expression levels. Silencing PRDM2 gene expression by RNA interference increased PRDM10 expression levels and reduced the proliferation rate of spermatogonia. Conclusions: In spermatogonia as in MCF-7 cell line, E2 and DHT regulate PRDM2 gene expression suggesting that PRDM2 gene products could mediate the effect of these agents on cell cycle progression. PRDM4 and PRDM10 are also responsive to steroid hormones and PRDM10 probably cooperates with PRDM2, as demonstrated by the increase of its expression levels after PRDM2 gene silencing.

Reactive oxygen species (ROS) constitute a group of highly reactive molecules that have evolved as regulators of important signaling pathways. It is now well accepted that moderate levels of ROS are required for several cellular functions, including gene expression. The production of ROS is elevated in tumor cells as a consequence of increased metabolic rate, gene mutation and relative hypoxia, and excess ROS are quenched by increased antioxidant enzymatic and nonenzymatic pathways in the same cells. Moderate increases of ROS contribute to several pathologic conditions, among which are tumor promotion and progression, as they are involved in different signaling pathways and induce DNA mutation. However, ROS are also able to trigger programmed cell death (PCD). Our review will emphasize the molecular mechanisms useful for the development of therapeutic strategies that are based on modulating ROS levels to treat cancer. Specifically, we will report on the growing data that highlight the role of ROS generated by different metabolic pathways as Trojan horses to eliminate cancer cells., Cancer: A Trojan horse to kill cancer cells Highly reactive molecules called reactive oxygen species (ROS), which at low levels are natural regulators of important signaling pathways in cells, might be recruited to act as “Trojan horses” to kill cancer cells. Researchers in Italy led by Bruno Perillo of the Institute of Food Sciences in Avelllino review the growing evidence suggesting that stimulating production of natural ROS species could become useful in treating cancer. Although ROS production is elevated in cancer cells it can also promote a natural process called programmed cell death. This normally regulates cell turnover, but could be selectively activated to target diseased cells. The authors discuss molecular mechanisms underlying the potential anti-cancer activity of various ROS-producing strategies, including drugs and light-stimulated therapies. They expect modifying the production of ROS to have potential for developing new treatments.

Recent studies have shown that hyperinsulinemia may increase the cancer risk. Moreover, many tumors demonstrate an increased activation of IR signaling pathways. Phosphatidylinositol 3-kinase (PI3K) is necessary for insulin action. In epithelial cells, which do not express GLUT4 and gluconeogenic enzymes, insulin-mediated PI3K activation regulates cell survival, growth, and motility. Although the involvement of the regulatory subunit of PI3K (p85αPI3K) in insulin signal transduction has been extensively studied, the function of its N-terminus remains elusive. It has been identified as a serine (S83) in thep85αPI3Kthat is phosphorylated by protein kinase A (PKA). To determine the molecular mechanism linking PKA to insulin-mediated PI3K activation, we usedp85αPI3Kmutated forms to prevent phosphorylation (p85A) or to mimic the phosphorylated residue (p85D). We demonstrated that phosphorylation ofp85αPI3KS83 modulates the formation of thep85αPI3K/IRS-1complex and its subcellular localization influencing the kinetics of the insulin signaling both on MAPK-ERK and AKT pathways. Furthermore, thep85αPI3KS83 phosphorylation plays a central role in the control of insulin-mediated cell proliferation, cell migration, and adhesion. This study highlights thep85αPI3KS83 role as a key regulator of cell proliferation and motility induced by insulin in MCF-7 cells breast cancer model.

The epidemic spread of obesity is nowadays recognized as a global health and economic burden, arising great interest in the scientific community. The rate of adult obesity steadily increases concomitantly with the cancer incidence. As has been comprehensively reported, obesity is included among the multiple cancer risk factors and can progressively cause and/or exacerbate certain cancer types, as colorectal and breast cancers. The term adiponcosis was forged precisely to emphasize the interconnection between obesity and cancer onset and progression. The underlying mechanisms of adiponcosis have not been fully elucidated yet, may vary on cancer type, and depend on body fat distribution. It has been proposed that insulin resistance and related chronic hyperinsulinemia, increased insulin-like growth factors production, chronic inflammation or increased bioavailability of steroid hormones could be responsible of cancer hallmarks. Additionally, it has been suggested that adipose tissue-derived hormones, cytokines and adipokines, such as leptin, adiponectin and inflammatory markers, may reflect mechanisms linked to tumorigenesis. This review summarizes the current evidence on pathways, hormones, cytokines and low-chronic inflammation subtending adiponconsis, focusing on breast and colorectal cancers. In addition, we analyzed the lifestyle interventions that could attenuate the driving forces of obesity-related cancer incidence and progression. Moreover, current targets and drugs, their pros and cons, as well as new mechanisms and targets with promising therapeutic potential in cancer are discussed. Depicting this complex interconnection will provide insights for establishing new therapeutic approaches to halt the obesity impacts and thwart cancer onset and progression.

The association between diabetes and cardiovascular diseases is well known. Related diabetes macro- and microangiopathies frequently induce hypoxia and consequently energy failure to satisfy the jeopardized myocardium basal needs. Additionally, it is widely accepted that diabetes impairs endothelial nitric oxide synthase (eNOS) activity, resulting in diminished nitric oxide (NO) bioavailability and consequent endothelial cell dysfunction. In this study, we analyzed the embryonic heart-derived H9c2 cell response to hypoxic stress after administration of a high glucose concentration to reproduce a condition often observed in diabetes. We observed that 24 h hypoxia exposure of H9c2 cells reduced cell viability compared to cells grown in normoxic conditions. Cytotoxicity and early apoptosis were increased after exposure to high glucose administration. In addition, hypoxia induced a RhoA upregulation and a Bcl-2 downregulation and lowered the ERK activation observed in normoxia at both glucose concentrations. Furthermore, a significant cell proliferation rate increases after the 1400 W iNOS inhibitor administration was observed. Again, hypoxia increased the expression level of myogenin, a marker of skeletal muscle cell differentiation. The cardiomyocyte gene expression profiles and morphology changes observed in response to pathological stimuli, as hypoxia, could lead to improper ventricular remodeling responsible for heart failure. Therefore, understanding cell signaling events that regulate cardiac response to hypoxia could be useful for the discovery of novel therapeutic approaches able to prevent heart diseases.

A major challenge in the clinical management of prostate cancer (PC) is to inhibit tumor growth and prevent metastatic spreading. In recent years, considerable efforts have been made to discover new compounds useful for PC therapy, and promising advances in this field were reached. Drugs currently used in PC therapy frequently induce resistance and PC progresses toward metastatic castration-resistant forms (mCRPC), making it virtually incurable. Curcumin, a commercially available nutritional supplement, represents an attractive therapeutic agent for mCRPC patients. In the present study, we compared the effects of chemotherapeutic drugs such as docetaxel, paclitaxel, and cisplatin, to curcumin, on two PC cell lines displaying a different metastatic potential: DU145 (moderate metastatic potential) and PC-3 (high metastatic potential). Our results revealed a dose-dependent reduction of DU145 and PC-3 cell viability upon treatment with curcumin similar to chemotherapeutic agents (paclitaxel, cisplatin, and docetaxel). Furthermore, we explored the EGFR-mediated signaling effects on ERK activation in DU145 and PC-3 cells. Our results showed that DU145 and PC-3 cells overexpress EGFR, and the treatment with chemotherapeutic agents or curcumin reduced EGFR expression levels and ERK activation. Finally, chemotherapeutic agents and curcumin reduced the size of DU145 and PC-3 spheroids and have the potential to induce apoptosis and also in Matrigel. In conclusion, despite different studies being carried out to identify the potential synergistic curcumin combinations with chemopreventive/therapeutic efficacy for inhibiting PC growth, the results show the ability of curcumin used alone, or in combinatorial approaches, to impair the size and the viability of PC-derived spheroids.

Muscle invasive bladder cancer (MIBC) is a widespread malignancy with a worse prognosis often related to a late diagnosis. For early-stage MIBC pts, a multidisciplinary approach is mandatory to evaluate the timing of neoadjuvant chemotherapy (NAC) and surgery. The current standard therapy is platinum-based NAC (MVAC-methotrexate, vinblastine, doxorubicin, and cisplatin or Platinum–Gemcitabine regimens) followed by radical cystectomy (RC) with lymphadenectomy. However, preliminary data from Vesper trial highlighted that dose-dense NAC MVAC is endowed with a good pathological response but shows low tolerability. In the last few years, translational-based research approaches have identified several candidate biomarkers of NAC esponsiveness, such as ERCC2, ERBB2, or DNA damage response (DDR) gene alterations. Moreover, the recent consensus MIBC molecular classification identified six molecular subtypes, characterized by different sensitivity to chemo- or targeted or immunotherapy, that could open a novel procedure for patient selection and also for neoadjuvant therapies. The Italian PURE-01 phase II Trial extended data on efficacy and resistance to Immune Checkpoint Inhibitors (ICIs) in this setting. In this review, we summarize the most relevant literature data supporting NAC use in MIBC, focusing on novel therapeutic strategies such as immunotherapy, considering the better patient stratification and selection emerging from novel molecular classification.

Prostate and bladder cancer represent the two most frequently diagnosed genito-urinary malignancies. Diet has been implicated in both prostate and bladder cancer. Given their prolonged latency and high prevalence rates, both prostate and bladder cancer represent attractive candidates for dietary preventive measures, including the use of nutritional supplements. Flavonols, a class of flavonoids, are commonly found in fruit and vegetables and are known for their protective effect against diabetes and cardiovascular diseases. Furthermore, a higher dietary intake of flavonols was associated with a lower risk of both bladder and prostate cancer in epidemiological studies. In this systematic review, we gathered all available evidence supporting the anti-cancer potential of selected flavonols (kaempferol, fisetin and myricetin) against bladder and prostate cancer. A total of 21, 15 and 7 pre-clinical articles on bladder or prostate cancer reporting on kaempferol, fisetin and myricetin, respectively, were found, while more limited evidence was available from animal models and epidemiological studies or clinical trials. In conclusion, the available evidence supports the potential use of these flavonols in prostate and bladder cancer, with a low expected toxicity, thus providing the rationale for clinical trials that explore dosing, settings for clinical use as well as their use in combination with other pharmacological and non-pharmacological interventions.

PRDM12 is a member of the PRDI-BF1 (positive regulatory domain I-binding factor 1) homologous domain (PRDM)-containing protein family, a subfamily of Kruppel-like zinc finger proteins, controlling key processes in the development of cancer. PRDM12 is expressed in a spatio-temporal manner in neuronal systems where it exerts multiple functions. PRDM12 is essential for the neurogenesis initiation and activation of a cascade of downstream pro-neuronal transcription factors in the nociceptive lineage. PRDM12 inactivation, indeed, results in a complete absence of the nociceptive lineage, which is essential for pain perception. Additionally, PRDM12 contributes to the early establishment of anorexigenic neuron identity and the maintenance of high expression levels of pro-opiomelanocortin, which impacts on the program bodyweight homeostasis. PRDMs are commonly involved in cancer, where they act as oncogenes/tumor suppressors in a “Yin and Yang” manner. PRDM12 is not usually expressed in adult normal tissues but its expression is re-activated in several cancer types. However, little information is currently available on PRDM12 expression in cancers and its mechanism of action has not been thoroughly described. In this review, we summarize the recent findings regarding PRDM12 by focusing on four main biological processes: neurogenesis, pain perception, oncogenesis and cell metabolism. Moreover, we wish to highlight the importance of future studies focusing on the PRDM12 signaling pathway(s) and its role in cancer onset and progression.

Objective Glioblastoma (GBM) is the most aggressive and common form of primary brain cancer. Survival is poor and improved treatment options are urgently needed. Dual specificity phosphatase-6 (DUSP6) is actively involved in oncogenesis showing unexpected tumor-promoting properties in human glioblastoma, contributing to the development and expression of the full malignant and invasive phenotype. The purpose of this study was to assess if DUSP6 activates epithelial-to-mesenchymal transition (EMT) in glioblastoma and its connection with the invasive capacity. Results We found high levels of transcripts mRNA by qPCR analysis in a panel of primary GBM compared to adult or fetal normal tissues. At translational levels, these data correlate with high protein expression and long half-life values by cycloheximide-chase assay in immunoblot experiments. Next, we demonstrate that DUSP6 gene is involved in epithelial-to-mesenchymal transition (EMT) in GBM by immunoblot characterization of the mesenchymal and epithelial markers. Vimentin, N-Cadherin, E-Cadherin and fibronectin were measured with and without DUSP6 over-expression, and in response to several stimuli such as chemotherapy treatment. In particular, the high levels of vimentin were blunted at increasing doses of cisplatin in condition of DUSP6 over-expression while N-Cadherin contextually increased. Finally, DUSP6 per se increased invasion capacity of GBM. Overall, our data unveil the DUSP6 involvement in invasive mesenchymal-like properties in GBM.

The PR/SET domain family (PRDM) comprise a family of genes whose protein products share a conserved N-terminal PR [PRDI-BF1 (positive regulatory domain I-binding factor 1) and RIZ1 (retinoblastoma protein-interacting zinc finger gene 1)] homologous domain structurally and functionally similar to the catalytic SET [Su(var)3-9, enhancer-of-zeste and trithorax] domain of histone methyltransferases (HMTs). These genes are involved in epigenetic regulation of gene expression through their intrinsic HMTase activity or via interactions with other chromatin modifying enzymes. In this way they control a broad spectrum of biological processes, including proliferation and differentiation control, cell cycle progression, and maintenance of immune cell homeostasis. In cancer, tumor-specific dysfunctions of PRDM genes alter their expression by genetic and/or epigenetic modifications. A common characteristic of most PRDM genes is to encode for two main molecular variants with or without the PR domain. They are generated by either alternative splicing or alternative use of different promoters and play opposite roles, particularly in cancer where their imbalance can be often observed. In this scenario, PRDM proteins are involved in cancer onset, invasion, and metastasis and their altered expression is related to poor prognosis and clinical outcome. These functions strongly suggest their potential use in cancer management as diagnostic or prognostic tools and as new targets of therapeutic intervention.

The human microbiota shows pivotal roles in urologic health and disease. Emerging studies indicate that gut and urinary microbiomes can impact several urological diseases, both benignant and malignant, acting particularly on prostate inflammation and prostate cancer. Indeed, the microbiota exerts its influence on prostate cancer initiation and/or progression mechanisms through the regulation of chronic inflammation, apoptotic processes, cytokines, and hormonal production in response to different pathogenic noxae. Additionally, therapies’ and drugs’ responses are influenced in their efficacy and tolerability by microbiota composition. Due to this complex potential interconnection between prostate cancer and microbiota, exploration and understanding of the involved relationships is pivotal to evaluate a potential therapeutic application in clinical practice. Several natural compounds, moreover, seem to have relevant effects, directly or mediated by microbiota, on urologic health, posing the human microbiota at the crossroad between prostatic inflammation and prostate cancer development. Here, we aim to analyze the most recent evidence regarding the possible crosstalk between prostate, microbiome, and inflammation.

Kv7.2-Kv7.5 channels mediate the M-current (IKM), a K+-selective current regulating neuronal excitability and representing an attractive target for pharmacological therapy against hyperexcitability diseases such as pain. Kv7 channels interact functionally with transient receptor potential vanilloid 1 (TRPV1) channels activated by endogenous and/or exogenous pain-inducing substances, such as bradykinin (BK) or capsaicin (CAP), respectively, however, whether Kv7 channels of specific molecular composition provide a dominant contribution in BK- or CAP-evoked responses is yet unknown. To this aim, Kv7 transcripts expression and function were assessed in F11 immortalized sensorial neurons, a cellular model widely used to assess nociceptive molecular mechanisms. In these cells, the effects of the pan-Kv7 activator retigabine were investigated, as well as the effects of ICA-27243 and (S)-1, two Kv7 activators acting preferentially on Kv7.2/Kv7.3 and Kv7.4/Kv7.5 channels, respectively, on BK- and CAP-induced changes in intracellular Ca2+ concentrations ([Ca2+]i). The results obtained revealed the expression of transcripts of all Kv7 genes, leading to an IKM-like current. Moreover, all tested Kv7 openers inhibited BK- and CAP-induced responses by a similar extent (~60%), at least for BK-induced Ca2+ responses, the potency of retigabine (IC50~1 &micro, M) was higher than that of ICA-27243 (IC50~5 &micro, M) and (S)-1 (IC50~7 &micro, M). Altogether, these results suggest that IKM activation effectively counteracts the cellular processes triggered by TRPV1-mediated pain-inducing stimuli, and highlight a possible critical contribution of Kv7.4 subunits.

Prostate cancer is one of the most commonly diagnosed cancers in men, and androgen deprivation therapy still represents the primary treatment for prostate cancer patients. This approach, however, frequently fails and patients develop castration-resistant prostate cancer, which is almost untreatable. Cancer cells are characterized by a hierarchical organization, and stem/progenitor cells are endowed with tumor-initiating activity. Accumulating evidence indicates that prostate cancer stem cells lack the androgen receptor and are, indeed, resistant to androgen deprivation therapy. In contrast, these cells express classical (α and/or ß) and novel (GPR30) estrogen receptors, which may represent new putative targets in prostate cancer treatment. In the present review, we discuss the still-debated mechanisms, both genomic and non-genomic, by which androgen and estradiol receptors (classical and novel) mediate the hormonal control of prostate cell stemness, transformation, and the continued growth of prostate cancer. Recent preclinical and clinical findings obtained using new androgen receptor antagonists, anti-estrogens, or compounds such as enhancers of androgen receptor degradation and peptides inhibiting non-genomic androgen functions are also presented. These new drugs will likely lead to significant advances in prostate cancer therapy.

PRDM (PRDI-BF1 and RIZ homology domain containing) protein family members are characterized by the presence of a PR domain and a variable number of Zn-finger repeats. Experimental evidence has shown that the PRDM proteins play an important role in gene expression regulation, modifying the chromatin structure either directly, through the intrinsic methyltransferase activity, or indirectly through the recruitment of chromatin remodeling complexes. PRDM proteins have a dual action: they mediate the effect induced by different cell signals like steroid hormones and control the expression of growth factors. PRDM proteins therefore have a pivotal role in the transduction of signals that control cell proliferation and differentiation and consequently neoplastic transformation. In this review, we describe pathways in which PRDM proteins are involved and the molecular mechanism of their transcriptional regulation.

Phosphoinositide-3-OH kinase (PI3K) signalling regulates various cellular processes, including cell survival, growth, proliferation and motility, and is among the most frequently mutated pathways in cancer. Although the involve- ment of p85αPI3K SH2 domain in signal transduction has been extensively studied, the function of the SH3 domain at the N-terminus remains elusive. A serine (at codon 83) adjacent to the N-terminal SH3 domain in the PI3K regulatory subunit p85αPI3K that is phosphorylated by protein kinase A (PKA) in vivo and in vitro has been identified. Virtually all recep- tors binding p85αPI3K can cooperate with cAMP-PKA signals via phosphorylation of p85αPI3KSer83. To analyse the role of p85αPI3KSer83 in retinoic acid (RA) and cAMP signalling, in MCF7 cells, we used p85αPI3K mutated forms, in which Ser83 has been substituted with alanine (p85A) to prevent phosphory- lation or with aspartic acid (p85D) to mimic the phosphorylated residue. We demonstrated that p85αPI3KSer83 is crucial for the synergistic enhancement of RARα/p85αPI3K binding induced by cAMP/RA co-treatment in MCF7 cells. Growth curves, colorimetric MTT assay and cell cycle analysis demonstrated that phosphorylation of p85αPI3KSer83 plays an important role in the control of MCF7 cell proliferation and in RA-induced inhibition of proliferation. Wound healing and transwell experi- ments demonstrated that p85αPI3KSer83 was also essential both for the control of migratory behaviour and for the reduction of motility induced by RA. This study points to p85αPI3KSer83 as the physical link between different pathways (cAMP-PKA, RA and FAK), and as an important regulator of MCF7 cell prolif- eration and migration.

""The retinoblastoma protein-interacting zinc-finger (RIZ) gene, also known as PRDM2, encodes two protein products, RIZ1 and RIZ2, differing for the presence of a 202 aa domain, called PR domain, at the N-terminus of the RIZ1 molecule. While the histone H3 K9 methyltransferase activity of RIZ1 is associated with the negative control of cell proliferation, no information is currently available on either expression regulation of the RIZ2 form or on its biological activity. RIZ proteins act as ER co-activators and promote optimal estrogen response in female reproductive tissues. In estrogen-responsive cells, 17-beta estradiol modulates RIZ gene expression producing a shift in the balanced expression of the two forms. Here, we demonstrate that an estrogen-responsive element (ERE) within the RIZ promoter 2 is regulated in a ligand-specific manner by ERa, through both the AF1 and AF2 domains. The pattern of ERa binding, histone H4 acetylation, and histone H3 cyclical methylation of lysine 9 was comparable to other estrogen-regulated promoters. Association of topoisomerase II beta with the RIZ promoter 2 confirmed the transcriptional activation induced by estrogen. We hypothesize that RIZ2, acting as a negative regulator of RIZ1 function, mediates the proliferative effect of estrogen through regulation of survival and differentiation gene expression. J. Cell. Physiol. 227: 964975, 2012. (C) 2011 Wiley Periodicals, Inc.""

Dual-specificity phosphatase 6 (DUSP6, mitogen-activated protein kinase (MAPK) phosphatase 3 or PYST1) dephosphorylates phosphotyrosine and phosphothreonine residues on extracellular signal-regulated kinase (ERK1/2; MAPK1/2) to inactivate the ERK1/2 kinase. DUSP6 is a critical regulator of the ERK signaling cascade and has been implicated as a tumor suppressor. We report here experimental evidences that DUSP6 is transcriptionally upregulated in primary and long-term cultures of human glioblastoma, as assayed by northern hybridization and real-time quantitative PCR, producing constitutive high level of protein expression. Functional assays were performed with adenovirus-mediated expression of DUSP6 in glioblastoma cultures. Protein overexpression inhibits growth by inducing G1-phase delay and increased mitogenic/anchorage dependence and clonogenic potential in vitro. Changes in cell morphology were associated with an increased tumor growth in vivo. Chemoresistance is a major cause of treatment failure and poor outcome in human glioblastomas. Importantly, DUSP6 overexpression increased resistance to cisplatin-mediated cell death in vitro and in vivo. Antisense-mediated depletion of DUSP6 acted in lowering the threshold to anticancer DNA-damaging drugs. We conclude that upregulation of DUSP6 exerts a tumor-promoting role in human glioblastomas exacerbating the malignant phenotype.

[This corrects the article DOI: 10.3389/fphar.2019.00028.]., (Copyright © 2024 Rossi, Di Zazzo, Galasso, De Rosa, Abbondanza, Sinisi, Altucci, Migliaccio and Castoria.)