Diagnostic and Prognostic Markers for Pancreatitis and Pancreatic Ductal Adenocarcinoma.

Diagnostic markers are desperately needed for the early detection of pancreatic ductal adenocarcinoma (PDA). We describe sets of markers expressed in temporal order in mouse models during pancreatitis, PDA initiation and progression. Cell type specificity and the differential expression of PDA markers were identified by screening single cell (sc) RNAseq from tumor samples of a mouse model for PDA (KIC) at early and late stages of PDA progression compared to that of a normal pancreas. Candidate genes were identified from three sources: (1) an unsupervised screening of the genes preferentially expressed in mouse PDA tumors; (2) signaling pathways that drive PDA, including the Ras pathway, calcium signaling, and known cancer genes, or genes encoding proteins that were identified by differential mass spectrometry (MS) of mouse tumors and conditioned media from human cancer cell lines; and (3) genes whose expression is associated with poor or better prognoses (PAAD, oncolnc.org). The developmental progression of PDA was detected in the temporal order of gene expression in the cancer cells of the KIC mice. The earliest diagnostic markers were expressed in epithelial cancer cells in early-stage, but not late-stage, PDA tumors. Other early markers were expressed in the epithelium of both early- and late-state PDA tumors. Markers that were expressed somewhat later were first elevated in the epithelial cancer cells of the late-stage tumors, then in both epithelial and mesenchymal cells, or only in mesenchymal cells. Stromal markers were differentially expressed in early- and/or late-stage PDA neoplasia in fibroblast and hematopoietic cells (lymphocytes and/or macrophages) or broadly expressed in cancer and many stromal cell types. Pancreatitis is a risk factor for PDA in humans. Mouse models of pancreatitis, including caerulein treatment and the acinar-specific homozygous deletion of differentiation transcription factors (dTFs), were screened for the early expression of all PDA markers identified in the KIC neoplasia. Prognostic markers associated with a more rapid decline were identified and showed differential and cell-type-specific expression in PDA, predominately in late-stage epithelial and/or mesenchymal cancer cells. Select markers were validated by immunohistochemistry in mouse and human samples of a normal pancreas and those with early- and late-stage PDA. In total, we present 2165 individual diagnostic and prognostic markers for disease progression to be tested in humans from pancreatitis to late-stage PDA.

Circulating tumour DNA: a challenging innovation to develop "precision onco-surgery" in pancreatic adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is predicted to become the third leading cause of cancer-related mortality within the next decade. Management of PDAC remains challenging with limited effective treatment options and a dismal long-term prognosis. Liquid biopsy and circulating biomarkers seem to be promising to improve the multidisciplinary approach in PDAC treatment. Circulating tumour DNA (ctDNA) is the most studied blood liquid biopsy analyte and can provide insight into the molecular profile and individual characteristics of the tumour in real-time and in advance of standard imaging modalities. This could pave the way for identifying new therapeutic targets and markers of tumour response to supplement diagnostic and provide enhanced stratified treatment. Although its specificity seems excellent, the current sensitivity of ctDNA remains a limitation for clinical use, especially in patients with a low tumour burden. Increasing evidence suggests that ctDNA is a pertinent candidate biomarker to assess minimal residual disease after surgery but also a strong independent prognostic biomarker. This review explores the current knowledge and recent developments in ctDNA as a screening, diagnostic, prognostic and predictive biomarker in the management of resectable PDAC but also technical and analytical challenges that must be overcome to move toward "precision onco-surgery."

High Values of Drain Fluid Epidermal Growth Factor and Transforming Growth Factor-Beta Are Associated with the Development of Pancreatic Fistula after Pancreatoduodenectomy.

INTRODUCTION: Postoperative inflammatory response may act as a major determinant of anastomotic failure after pancreaticoduodenectomy. In this pilot study, we investigated the potential role of drain fluid cytokines in predicting postoperative pancreatic fistula (POPF). METHODS: Drain fluid TGF-ß, IGF-1, EGF, and IL-6, together with serum amylase and drain fluid amylase, were measured on POD1 and correlated with the development of POPF. RESULTS: The study population consisted of 66 patients. POPF and Clavien-Dindo ≥3 morbidity rates were 12.1% and 9.1%, respectively. Patients developing POPF presented significantly higher values of POD1 serum amylase level (477 vs. 54 UI/L, p < 0.001), drain fluid amylase (7,500 vs. 127 UI/L, p < 0.001), TGFß (94 vs. 40 pg/g, p = 0.045), and EGF (17 vs. 13, p = 0.015). There were no differences in terms of IGF-1 and IL-6 values. CONCLUSION: Assessing the local inflammatory response after pancreatoduodenectomy could represent a promising field of research since both TGFß and EGF seem to be associated with the occurrence of POPF.

Knockout mouse models reveal the contributions of G protein subunits to complement C5a receptor-mediated chemotaxis.

G protein-coupled receptor signaling is required for the navigation of immune cells along chemoattractant gradients. However, chemoattractant receptors may couple to more than one type of heterotrimeric G protein, each of which consists of a Gα, Gß, and Gγ subunit, making it difficult to delineate the critical signaling pathways. Here, we used knockout mouse models and time-lapse microscopy to elucidate Gα and Gß subunits contributing to complement C5a receptor-mediated chemotaxis. Complement C5a-mediated chemokinesis and chemotaxis were almost completely abolished in macrophages lacking Gnai2 (encoding Gαi2), consistent with a reduced leukocyte recruitment previously observed in Gnai2-/- mice, whereas cells lacking Gnai3 (Gαi3) exhibited only a slight decrease in cell velocity. Surprisingly, C5a-induced Ca2+ transients and lamellipodial membrane spreading were persistent in Gnai2-/- macrophages. Macrophages lacking both Gnaq (Gαq) and Gna11 (Gα11) or both Gna12 (Gα12) and Gna13 (Gα13) had essentially normal chemotaxis, Ca2+ signaling, and cell spreading, except Gna12/Gna13-deficient macrophages had increased cell velocity and elongated trailing ends. Moreover, Gnaq/Gna11-deficient cells did not respond to purinergic receptor P2Y2 stimulation. Genetic deletion of Gna15 (Gα15) virtually abolished C5a-induced Ca2+ transients, but chemotaxis and cell spreading were preserved. Homozygous Gnb1 (Gß1) deletion was lethal, but mice lacking Gnb2 (Gß2) were viable. Gnb2-/- macrophages exhibited robust Ca2+ transients and cell spreading, albeit decreased cell velocity and impaired chemotaxis. In summary, complement C5a-mediated chemotaxis requires Gαi2 and Gß2, but not Ca2+ signaling, and membrane protrusive activity is promoted by G proteins that deplete phosphatidylinositol 4,5-bisphosphate.

The curious case of Gαs gain-of-function in neoplasia.

BACKGROUND: Mutations activating the α subunit of heterotrimeric Gs protein are associated with a number of highly specific pathological molecular phenotypes. One of the best characterized is the McCune Albright syndrome. The disease presents with an increased incidence of neoplasias in specific tissues. MAIN BODY: A similar repertoire of neoplasms can develop whether mutations occur spontaneously in somatic tissues during fetal development or after birth. Glands are the most "permissive" tissues, recently found to include the entire gastrointestinal tract. High frequency of activating Gαs mutations is associated with precise diagnoses (e.g., IPMN, Pyloric gland adenoma, pituitary toxic adenoma). Typically, most neoplastic lesions, from thyroid to pancreas, remain well differentiated but may be a precursor to aggressive cancer. CONCLUSIONS: Here we propose the possibility that gain-of-function mutations of Gαs interfere with signals in the microenvironment of permissive tissues and lead to a transversal neoplastic phenotype.

Immunomodulation after radiofrequency ablation of locally advanced pancreatic cancer by monitoring the immune response in 10 patients.

OBJECTIVE/BACKGROUND: RFA of pancreatic cancer has been demonstrated to be feasible and safe with a positive impact on survival. The aim was to investigate whether an immune reaction is activated after locally advanced pancreatic cancer (LAPC) ablation. METHODS: Peripheral Blood samples were obtained preoperatively and on post-operative days 3-30. Evaluated parameters were: cells [CD4+, CD8+ and activated subsets, T-Reg, Monocytes, myeloid and plasmocytoid Dendritic cells (mDC and pDC)] and cytokines [Interleukin (IL)-6, Stromal-cells derived factor (SDF)-1, IL-1ß, Tumour-Necrosis Factor (TNF)-α, Interferon (IFN)-γ, Vascular Endothelial Growth Factor (VEGF), chemokine (C-C motif) ligand 5 (CCL-5), Transforming-Growth Factor (TGF)-ß]. RESULTS: Ten patients were enrolled. CD4+, CD8+ and TEM increased from day 3 suggesting the activation of the adaptive response. Immunosuppressive T-Reg cells were stable despite the possibility that laparotomy and heating might favour their expansion. Myeloid DCs, that present tumour-associated antigens, increased at day 30. RFA dramatically increased circulating IL-6 at day 3 but this decreased to baseline by day 30, consistent with the supposed anti-tumour effect. RFA did not significantly modulate essential chemokines, such as CCL-5 and SDF1, VEGF, TGF-ß and TNF-α, that favour tumour-growth by sustaining cancer angiogenesis and fuelling tumour-associated inflammation. CONCLUSIONS: This study provides the first evidence of RFA-based immunomodulation in LAPC. We observed a general activation of adaptive response along with a decrease of immunosuppression. Furthermore, most cells showed prolonged activation some weeks after the procedure, suggesting true immunomodulation rather than a normal inflammatory response.

The Placenta as a Source of Human Material for Neuronal Repair.

Stem cell therapy has the potential to meet unsolved problems in tissue repair and regeneration, particularly in the neural tissues. However, an optimal source has not yet been found. Growing evidence indicates that positive effects produced in vivo by mesenchymal stem cells (MSCs) can be due not only to their plasticity but also to secreted molecules including extracellular vesicles (EVs) and the extracellular matrix (ECM). Trophic effects produced by MSCs may reveal the key to developing effective tissue-repair strategies, including approaches based on brain implants or other implantable neural electrodes. In this sense, MSCs will become increasingly valuable and needed in the future. The placenta is a temporary organ devoted to protecting and supporting the fetus. At the same time, the placenta represents an abundant and extremely convenient source of MSCs. Nonetheless, placenta-derived MSCs (P-MSCs) remain understudied as compared to MSCs isolated from other sources. This review outlines the limited literature describing the neuroregenerative effects of P-MSC-derived biomaterials and advocates for exploiting the potential of this untapped source for human regenerative therapies.

G Protein-Coupled Receptors and the Rise of Type 2 Diabetes in Children.

The human genome counts hundreds of GPCRs specialized to sense thousands of different extracellular cues, including light, odorants and nutrients in addition to hormones. Primordial GPCRs were likely glucose transporters that became sensors to monitor the abundance of nutrients and direct the cell to switch from aerobic metabolism to fermentation. Human ß cells express multiple GPCRs that contribute to regulate glucose homeostasis, cooperating with many others expressed by a variety of cell types and tissues. These GPCRs are intensely studied as pharmacological targets to treat type 2 diabetes in adults. The dramatic rise of type 2 diabetes incidence in pediatric age is likely correlated to the rapidly evolving lifestyle of children and adolescents of the new century. Current pharmacological treatments are based on therapies designed for adults, while youth and puberty are characterized by a different hormonal balance related to glucose metabolism. This review focuses on GPCRs functional traits that are relevant for ß cells function, with an emphasis on aspects that could help to differentiate new treatments specifically addressed to young type 2 diabetes patients.

cAMP Response Element-Binding Protein Controls the Appearance of Neuron-Like Traits in Chorion Mesenchymal Cells.

BACKGROUND: Mesenchymal stromal cells (MSC) from bone marrow have been reported to undergo the initial phases of neural differentiation in response to an increase of intracellular cAMP. We investigated the possibility that a similar effect applies to chorion-derived MSC. METHODS: The intracellular concentration of cAMP was increased either by forskolin, to promote its synthesis, or by inhibitors of its degradation. The consequent reduction in the expression of mesenchymal markers was associated with the appearance of neuron-like morphology in a subset of cells. The effect was measured and characterized using biomarkers and an inhibitor of cAMP response element-binding protein (CREB). RESULTS: The dramatic morphological change induced by all the treatments that promoted intracellular cAMP was transient and peaked on the third day. After that, cells returned to the typical fibroblast-like appearance within 24 hours. The distinctive morphology was associated to the expression of neuregulin 1, doublecortin, neuron-specific class III ß-tubulin, and required cAMP response element-binding protein activity. Basic-fibroblast growth factor (b-FGF) treatment increased both the timeframe and number of cells undergoing the morphological change induced by the effect of forskolin. As opposite, arginine-vasopressin (AVP) and sphingosine-1-phosphate (S1P) reduced it. CONCLUSIONS: We conclude that cAMP and the ensuing CREB activation trigger a preliminary step towards neuronal differentiation of chorion-derived MSC. However, likewise other MSC, the stimulus is not sufficient to promote stable differentiation.

Landscape of Druggable Molecular Pathways Downstream of Genomic CDH1/Cadherin-1 Alterations in Gastric Cancer.

Loss of CDH1/Cadherin-1 is a common step towards the acquisition of an abnormal epithelial phenotype. In gastric cancer (GC), mutation and/or downregulation of CDH1/Cadherin-1 is recurrent in sporadic and hereditary diffuse GC type. To approach the molecular events downstream of CDH1/Cadherin-1 alterations and their relevance in gastric carcinogenesis, we queried public databases for genetic and DNA methylation data in search of molecular signatures with a still-uncertain role in the pathological mechanism of GC. In all GC subtypes, modulated genes correlating with CDH1/Cadherin-1 aberrations are associated with stem cell and epithelial-to-mesenchymal transition pathways. A higher level of genes upregulated in CDH1-mutated GC cases is associated with reduced overall survival. In the diffuse GC (DGC) subtype, genes downregulated in CDH1-mutated compared to cases with wild type CDH1/Cadherin-1 resulted in being strongly intertwined with the DREAM complex. The inverse correlation between hypermethylated CpGs and CDH1/Cadherin-1 transcription in diverse subtypes implies a common epigenetic program. We identified nonredundant protein-encoding isoforms of 22 genes among those differentially expressed in GC compared to normal stomach. These unique proteins represent potential agents involved in cell transformation and candidate therapeutic targets. Meanwhile, drug-induced and CDH1/Cadherin-1 mutation-related gene expression comparison predicts FIT, GR-127935 hydrochloride, amiodarone hydrochloride in GC and BRD-K55722623, BRD-K13169950, and AY 9944 in DGC as the most effective treatments, providing cues for the design of combined pharmacological treatments. By integrating genetic and epigenetic aspects with their expected functional outcome, we unveiled promising targets for combinatorial pharmacological treatments of GC.

Physical Activity Modulates miRNAs Levels and Enhances MYOD Expression in Myoblasts.

Stem cells functions are regulated by different factors and non-conding RNAs, such as microRNA. MiRNAsplay an important role in modulating the expression of genes involved in the commitment and differentiation of progenitor cells. MiRNAs are post transcriptional regulators which may be modulated by physical exercise. MiRNAs, by regulating different signaling pathways, play an important role in myogenesis as well as in muscle activity. MiRNAs quantification may be considered for evaluating physical performance or muscle recovery. With the aim to identify specific miRNAs potentially involved in myogenesis and modulated by physical activity, we investigated miRNAs expression following physical performance in Peripheral Blood Mononuclear Cells (PBMCs) and in sera of half marathon (HM) runnners. The effect of runners sera on Myogenesis in in vitro cellular models was also explored. Therefore, we performed Microarray Analysis and Real Time PCR assays, as well as in vitro cell cultures analysis to investigate myogenic differentiation. Our data demonstrated gender-specific expression patterns of PBMC miRNAs before physical performance. In particular, miR223-3p, miR26b-5p, miR150-5p and miR15-5p expression was higher, while miR7a-5p and miR7i-5p expression was lower in females compared to males. After HM, miR152-3p, miR143-3p, miR27a-3p levels increased while miR30b-3p decreased in both females and males: circulating miRNAs mirrored these modulations. Furthermore, we also observed that the addition of post-HM participants sera to cell cultures exerted a positive effect in stimulating myogenesis. In conclusion, our data suggest that physical activity induces the modulation of myogenesis-associated miRNAs in bothfemales and males, despite the gender-associated different expression of certain miRNAs, Noteworthy, these findings might be useful for evaluating potential targets for microRNA based-therapies in diseases affecting the myogenic stem cells population.

Mitoxantrone-Loaded Nanoferritin Slows Tumor Growth and Improves the Overall Survival Rate in a Subcutaneous Pancreatic Cancer Mouse Model.

Pancreatic cancer (PC) represents an intriguing topic for researchers. To date, the prognosis of metastasized PC is poor with just 7% of patients exceeding a five-year survival period. Thus, molecular modifications of existing drugs should be developed to change the course of the disease. Our previously generated nanocages of Mitoxantrone (MIT) encapsulated in human H-chain Ferritin (HFt), designated as HFt-MP-PASE-MIT, has shown excellent tumor distribution and extended serum half-life meriting further investigation for PC treatment. Thus, in this study, we used the same nano-formulation to test its cytotoxicity using both in vitro and in vivo assays. Interestingly, both encapsulated and free-MIT drugs demonstrated similar killing capabilities on PaCa44 cell line. Conversely, in vivo assessment in a subcutaneous PaCa44 tumor model of PC demonstrated a remarkable capability for encapsulated MIT to control tumor growth and improve mouse survival with a median survival rate of 65 vs. 33 days for loaded and free-MIT, respectively. Interestingly, throughout the course of mice treatment, MIT encapsulation did not present any adverse side effects as confirmed by histological analysis of various murine tissue organs and body mass weights. Our results are promising and pave the way to effective PC targeted chemotherapy using our HFt nanodelivery platforms.

Gα15 in early onset of pancreatic ductal adenocarcinoma.

The GNA15 gene is ectopically expressed in human pancreatic ductal adenocarcinoma cancer cells. The encoded Gα15 protein can promiscuously redirect GPCR signaling toward pathways with oncogenic potential. We sought to describe the distribution of GNA15 in adenocarcinoma from human pancreatic specimens and to analyze the mechanism driving abnormal expression and the consequences on signaling and clinical follow-up. We detected GNA15 expression in pre-neoplastic pancreatic lesions and throughout progression. The analysis of biological data sets, primary and xenografted human tumor samples, and clinical follow-up shows that elevated expression is associated with poor prognosis for GNA15, but not any other GNA gene. Demethylation of the 5' GNA15 promoter region was associated with ectopic expression of Gα15 in pancreatic neoplastic cells, but not in adjacent dysplastic or non-transformed tissue. Down-modulation of Gα15 by shRNA or CRISPR/Cas9 affected oncogenic signaling, and reduced adenocarcimoma cell motility and invasiveness. We conclude that de novo expression of wild-type GNA15 characterizes transformed pancreatic cells. The methylation pattern of GNA15 changes in preneoplastic lesions coincident with the release a transcriptional blockade that allows ectopic expression to persist throughout PDAC progression. Elevated GNA15 mRNA correlates with poor prognosis. In addition, ectopic Gα15 signaling provides an unprecedented mechanism in the early steps of pancreas carcinogenesis distinct from classical G protein oncogenic mutations described previously in GNAS and GNAQ/GNA11.

The ocular albinism type 1 protein, an intracellular G protein-coupled receptor, regulates melanosome transport in pigment cells.

The protein product of the ocular albinism type 1 gene, named OA1, is a pigment cell-specific G protein-coupled receptor exclusively localized to intracellular organelles, namely lysosomes and melanosomes. Loss of OA1 function leads to the formation of macromelanosomes, suggesting that this receptor is implicated in organelle biogenesis, however the mechanism involved in the pathogenesis of the disease remains obscure. We report here the identification of an unexpected abnormality in melanosome distribution both in retinal pigment epithelium (RPE) and skin melanocytes of Oa1-knock-out (KO) mice, consisting in a displacement of the organelles from the central cytoplasm towards the cell periphery. Despite their depletion from the microtubule (MT)-enriched perinuclear region, Oa1-KO melanosomes were able to aggregate at the centrosome upon disruption of the actin cytoskeleton or expression of a dominant-negative construct of myosin Va. Consistently, quantification of organelle transport in living cells revealed that Oa1-KO melanosomes displayed a severe reduction in MT-based motility; however, this defect was rescued to normal following inhibition of actin-dependent capture at the cell periphery. Together, these data point to a defective regulation of organelle transport in the absence of OA1 and imply that the cytoskeleton might represent a downstream effector of this receptor. Furthermore, our results enlighten a novel function for OA1 in pigment cells and suggest that ocular albinism type 1 might result from a different pathogenetic mechanism than previously thought, based on an organelle-autonomous signalling pathway implicated in the regulation of both membrane traffic and transport.

Transglutaminase participates in the blockade of neurotransmitter release by tetanus toxin: evidence for a novel biological function.

Inhibition of neuroexocytosis by tetanus neurotoxin (TeNT) involves VAMP-2/synaptobrevin-2 cleavage. However, deletion of the TeNT activity does not completely abolish its inhibitory action. TeNT is a potent activator of the cross-linking enzyme transglutaminase 2 (TGase 2) in vitro. The role of the latter mechanism in TeNT poisoning was investigated in isolated nerve terminals and intact neurons. TeNT-induced inhibition of glutamate release from rat cortical synaptosomes was associated with a simultaneous activation of neuronal transglutaminase (TGase) activity. The TeNT-induced blockade of neuroexocytosis was strongly attenuated by pretreatment of either live Aplysia neurons or isolated nerve terminals with specific TGase inhibitors or neutralizing antibodies. The same treatments completely abolished the residual blockade of neuroexocytosis of a non-proteolytic mutant of TeNT light chain. Electrophysiological studies indicated that TGase activation occurs at an early step of TeNT poisoning and contributes to the inhibition of transmitter release. Bioinformatics and biochemical analyses identified synapsin I and SNAP-25 as potential presynaptic TGase substrates in isolated nerve terminals, which are potentially involved in the inhibitory action of TeNT. The results suggest that neuronal TGase activity plays an important role in the regulation of neuroexocytosis and is one of the intracellular targets of TeNT in neurons.

Cocoa Flavonoids Reduce Inflammation and Oxidative Stress in a Myocardial Ischemia-Reperfusion Experimental Model.

: Consumption of flavonoid-rich nutraceuticals has been associated with a reduction in coronary events. The present study analyzed the effects of cocoa flavonols on myocardial injury following acute coronary ischemia-reperfusion (I/R). A commercially available cocoa extract was identified by chromatographic mass spectrometry. Nineteen different phenolic compounds were identified and 250 mg of flavan-3-ols (procyanidin) were isolated in 1 g of extract. Oral administration of cocoa extract in incremental doses from 5 mg/kg up to 25 mg/kg daily for 15 days in Sprague Dawley rats (n = 30) produced a corresponding increase of blood serum polyphenols and become constant after 15 mg/kg. Consequently, the selected dose (15 mg/kg) of cocoa extract was administered orally daily for 15 days in a treated group (n = 10) and an untreated group served as control (n = 10). Both groups underwent surgical occlusion of the left anterior descending coronary artery and reperfusion. Cocoa extract treatment significantly reversed membrane peroxidation, nitro-oxidative stress, and decreased inflammatory markers (IL-6 and NF-kB) caused by myocardial I/R injury and enhanced activation of both p-Akt and p-Erk1/2. Daily administration of cocoa extract in rats is protective against myocardial I/R injury and attenuate nitro-oxidative stress, inflammation, and mitigates myocardial apoptosis.

A Potential Role of RUNX2- RUNT Domain in Modulating the Expression of Genes Involved in Bone Metastases: An In Vitro Study with Melanoma Cells.

Ectopic expression of RUNX2 has been reported in several tumors. In melanoma cells, the RUNT domain of RUNX2 increases cell proliferation and migration. Due to the strong link between RUNX2 and skeletal development, we hypothesized that the RUNT domain may be involved in the modulation of mechanisms associated with melanoma bone metastasis. Therefore, we evaluated the expression of metastatic targets in wild type (WT) and RUNT KO melanoma cells by array and real-time PCR analyses. Western blot, ELISA, immunofluorescence, migration and invasion ability assays were also performed. Our findings showed that the expression levels of bone sialoprotein (BSP) and osteopontin (SPP1) genes, which are involved in malignancy-induced hypercalcemia, were reduced in RUNT KO cells. In addition, released PTHrP levels were lower in RUNT KO cells than in WT cells. The RUNT domain also contributes to increased osteotropism and bone invasion in melanoma cells. Importantly, we found that the ERK/p-ERK and AKT/p-AKT pathways are involved in RUNT-promoted bone metastases. On the basis of our findings, we concluded that the RUNX2 RUNT domain is involved in the mechanisms promoting bone metastasis of melanoma cells via complex interactions between multiple players involved in bone remodeling.

Publisher Correction: Runx2 stimulates neoangiogenesis through the Runt domain in melanoma.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Methylation Dynamics of RASSF1A and Its Impact on Cancer.

5-methyl cytosine (5mC) is a key epigenetic mark entwined with gene expression and the specification of cellular phenotypes. Its distribution around gene promoters sets a barrier for transcriptional enhancers or inhibitor proteins binding to their target sequences. As a result, an additional level of regulation is added to the signals that organize the access to the chromatin and its structural components. The tumor suppressor gene RASSF1A is a microtubule-associated and multitasking scaffold protein communicating with the RAS pathway, estrogen receptor signaling, and Hippo pathway. RASSF1A action stimulates mitotic arrest, DNA repair and apoptosis, and controls the cell cycle and cell migration. De novo methylation of the RASSF1A promoter has received much attention due to its increased frequency in most cancer types. RASSF1A methylation is preceded by histones modifications and could represent an early molecular event in cell transformation. Accordingly, RASSF1A methylation is proposed as an epigenetic candidate marker in many cancer types, even though an inverse correlation of methylation and expression remains to be fully ascertained. Some findings indicate that the epigenetic abrogation of RASSF1A can promote the alternative expression of the putative oncogenic isoform RASSF1C. Understanding the complexity and significance of RASSF1A methylation is instrumental for a more accurate determination of its biological and clinical role. The review covers the molecular events implicated in RASSF1A methylation and gene silencing and provides a deeper view into the significance of the RASSF1A methylation patterns in a number of gastrointestinal cancer types.