Neuroblastoma cell proliferation is sensitive to changes in levels of RUNX1 and RUNX3 protein

Differential RNA Expression Between Metastatic and Primary Neuroblastoma Cells

INTRODUCTION

Neuroblastoma (NB) is the most common extra-cranial malignancy in children. Poor survival in high-risk NB is attributed to recurrent metastatic disease. To better study metastatic disease, we used a novel mouse model to investigate differential gene expression between primary tumor cells and metastatic cells. We hypothesized that metastatic NB cells have a different gene expression profile from primary tumor cells and cultured cells.

METHODS

Using three human NB cell lines (NGP, CHLA255, and SH-SY5Y), orthotopic xenografts were established in immunodeficient nod/scid gamma mice via subcapsular renal injection. Mice were sacrificed and NB cells were isolated from the primary tumor and from sites of metastasis (bone marrow, liver). RNA sequencing, gene set analysis, and pathway analysis were performed to identify differentially expressed genes and molecular pathways in the metastatic cells compared to primary tumor cells.

RESULTS

There were 266 differentially expressed genes in metastatic tumor cells (bone marrow and liver combined) compared to primary tumor cells. The top upregulated gene was KCNK1 and the top downregulated genes were PDE7B and NEBL. Top upregulated pathways in the metastatic cells were involved in ion transport, cell signaling, and cell proliferation. Top downregulated pathways were involved in DNA synthesis, transcription, and cellular metabolism.

CONCLUSIONS

In metastatic NB cells, our study identified the upregulation of biologic processes involved in cell cycle regulation, cell proliferation, migration, and invasion. Ongoing studies aim to validate downstream translation of these genomic alterations, as well as target these pathways to more effectively suppress and inhibit recurrent metastatic disease in NB.

Runt-related transcription factors in human carcinogenesis: a friend or foe?

PURPOSE

Cancer is one of the deadliest pathologies with more than 19 million new cases and 10 million cancer-related deaths across the globe. Despite development of advanced therapeutic interventions, cancer remains as a fatal pathology due to lack of early prognostic biomarkers, therapy resistance and requires identification of novel drug targets.

METHODS

Runt-related transcription factors (Runx) family controls several cellular and physiological functions including osteogenesis. Recent literatures from PubMed was mined and the review was written in comprehensive manner RESULTS: Recent literature suggests that aberrant expression of Runx contributes to tumorigenesis of many organs. Conversely, cell- and tissue-specific tumor suppressor roles of Runx are also reported. In this review, we have provided the structural/functional properties of Runx isoforms and its regulation in context of human cancer. Moreover, in an urgent need to discover novel therapeutic interventions against cancer, we comprehensively discussed the reported oncogenic and tumor suppressive roles of Runx isoforms in several tumor types and discussed the discrepancies that may have risen on Runx as a driver of malignant transformation.

CONCLUSION

Runx may be a novel therapeutic target against a battery of deadly human cancers.

The RUNX Family Defines Trk Phenotype and Aggressiveness of Human Neuroblastoma through Regulation of p53 and MYCN

The Runt-related transcription factor (RUNX) family, which is essential for the differentiation of cells of neural crest origin, also plays a potential role in neuroblastoma tumorigenesis. Consecutive studies in various tumor types have demonstrated that the RUNX family can play either pro-tumorigenic or anti-tumorigenic roles in a context-dependent manner, including in response to chemotherapeutic agents. However, in primary neuroblastomas, RUNX3 acts as a tumor-suppressor, whereas RUNX1 bifunctionally regulates cell proliferation according to the characterized genetic and epigenetic backgrounds, including MYCN oncogenesis. In this review, we first highlight the current knowledge regarding the mechanism through which the RUNX family regulates the neurotrophin receptors known as the tropomyosin-related kinase (Trk) family, which are significantly associated with neuroblastoma aggressiveness. We then focus on the possible involvement of the RUNX family in functional alterations of the p53 family members that execute either tumor-suppressive or dominant-negative functions in neuroblastoma tumorigenesis. By examining the tripartite relationship between the RUNX, Trk, and p53 families, in addition to the oncogene MYCN, we endeavor to elucidate the possible contribution of the RUNX family to neuroblastoma tumorigenesis for a better understanding of potential future molecular-based therapies.

RUNX Binding Sites Are Enriched in Herpesvirus Genomes, and RUNX1 Overexpression Leads to Herpes Simplex Virus 1 Suppression

Herpes simplex virus 1 (HSV-1) and HSV-2 can efficiently establish lifelong, transcriptionally silent latency states in sensory neurons to escape host detection. While host factors have previously been associated with long-range insulators in the viral genome, it is still unknown whether host transcription factors can repress viral genes more proximately to promote latency in dorsal root ganglion (DRG) neurons. Here, we assessed whether RUNX (runt-related transcription factor) transcription factors, which are critical in the development of sensory neurons, could be binding HSV-1 genome directly to suppress viral gene expression and lytic infection. Using previously published transcriptome sequencing data, we confirmed that mouse DRG neurons highly express Runx1 mRNA. Through computational analysis of HSV-1 and HSV-2 genomes, we observed that putative RUNX consensus binding sites (CBSs) were more enriched and more closely located to viral gene transcription start sites than would be expected by chance. We further found that RUNX CBSs were significantly more enriched among genomes of herpesviruses compared to those of nonherpesviruses. Utilizing an in vitro model of HSV-1 infection, we found that overexpressed RUNX1 could bind putative binding sites in the HSV-1 genome, repress numerous viral genes spanning all three kinetic classes, and suppress productive infection. In contrast, knockdown of RUNX1 in neuroblastoma cells induced viral gene expression and increased HSV-1 infection in vitro In sum, these data support a novel role for RUNX1 in directly binding herpesvirus genome, silencing the transcription of numerous viral genes, and ultimately limiting overall infection.IMPORTANCE Infecting 90% of the global population, HSV-1 and HSV-2 represent some of the most prevalent viruses in the world. Much of their success can be attributed to their ability to establish lifelong latent infections in the dorsal root ganglia (DRG). It is still largely unknown, however, how host transcription factors are involved in establishing this latency. Here, we report that RUNX1, expressed highly in DRG, binds HSV-1 genome, represses transcription of numerous viral genes, and suppresses productive in vitro infection. Our computational work further suggests this strategy may be used by other herpesviruses to reinforce latency in a cell-specific manner.

Runt-related transcription factor 1 promotes apoptosis and inhibits neuroblastoma progression in vitro and in vivo

Background

Runt-related transcription factor 1 (RUNX1) is a heterodimeric transcription factor that binds to the core element of many enhancers and promoters and can accelerate apoptosis in various tumors. However, the regulatory mechanisms underlying RUNX1 expression in neuroblastoma (NB), a highly malignant tumor in childhood, remain largely unclear. In this study, we aimed to assess the role of RUNX1 in NB and to reveal the underlying mechanisms that may contribute to finding a potential therapeutics strategy against NB.

Methods

Growth, invasion, metastasis and angiogenesis were assessed using Cell Counting Kit-8 (CCK-8) immunocytochemistry, and studies involving soft agar, cell invasion, tube formation and whole animals. The levels of expression were measured using real-time quantitative PCR for RNA, Western blot and immunostaining analyses for proteins. Luciferase reporter and chromatin immunoprecipitation assays indicated that RUNX1 directly binds within the BIRC5, CSF2RB and NFKBIA promoter regions to facilitate transcription. The level of apoptosis was assessed by determining mitochondrial membrane potential and flow cytometry.

Results

RUNX1 was highly expressed in ganglioneuroma (GN) and well-differentiated (WD) tissues relative to the poorly differentiated (PD) and undifferentiated (UD) ones. Moreover, RUNX1 effectively reduced cell viability, invasion, metastasis, angiogenesis, and promoted apoptosis in vitro and in vivo. RUNX1 reduced BIRC5 transcription and increased CSF2RB and NFKBIA transcription by directly binding BIRC5, CSF2RB and NFKBIA promoters. In addition, cytotoxic drugs, especially cisplatin, significantly increased RUNX1 expression in NB cells and promoted apoptosis.

Conclusions

These data show that RUNX1 is an independent surrogate marker for the progression of NB and it can be used for monitoring NB prognosis during therapy.

Neuroblastoma in Adolescents and Children Older than 10 Years: Unusual Clinicopathologic and Biologic Features

Neuroblastoma (NB) in children older than 10 years is rare. We reviewed our archives for patients with NB aged 10 to 18 years and summarized their clinicopathologic/genetic records. Of 96 patients, 4 patients were identified in this age group. Four tumors were abdominal; 1 patient had 2 tumors at diagnosis, one of which was presacral. Tumor sizes ranged from 3 to 20 cm. All tumors were high risk at clinical stages 3 and 4, with metastasis to bone marrow and other areas. Four tumors were poorly differentiated with unfavorable histology and one patient with bilateral adrenal disease had an intermixed ganglioneuroblastoma on one side. Another tumor exhibited pheochromocytoma-like morphology. MYCN amplification was present in bone marrow metastasis in one case. Complex chromosomal gains and 19p deletions were common. Exome sequencing revealed ALK variants in 2 cases and previously unreported MAGI2, RUNX1, and MLL mutations. All patients received standard chemotherapy and 2 patients received ALK-targeted trial therapy. Three patients died of disease, ranging 18 to 23 months after diagnosis. One patient has active disease and is receiving trial therapy. In conclusion, NB in children older than 10 years may exhibit unusual clinicopathologic and genetic features with large tumors, bilateral adrenal disease, rare morphologic features, complex DNA microarray findings and novel mutations. Patients often have grim prognoses despite genomic profiling-guided targeted therapy.

Regulation and function of runt-related transcription factors (RUNX1 and RUNX2) in goat granulosa cells

Transcription factors, runt-related transcription factor 1 (RUNX1) and 2 (RUNX2), belong to the runt-related (RUNX) gene family and play critical roles in mammalian reproduction processes. However, the regulatory mechanisms of RUNX1 and RUNX2 expression or their functions in goat follicles remain largely unknown. Herein, RUNX1 and RUNX2 proteins were detected in the oocytes and granulosa cells of preantral and antral follicles, as well as corpus luteum by immunohistochemistry. Treatments with human chorionic gonadotropin (hCG) or with the agonists and inhibitors of hCG-induced intracellular signaling pathways in granulosa cells in vitro, we found that hCG increased RUNX1 expression by activating PKC and PI3K signaling molecules, and increased RUNX2 expression by activating adenylate cyclase, PKC, and PI3K signaling molecules. We also demonstrated that miR-181b expression is dependent on the hCG-induced activation of PKC and PKA, and miR-222 expression is dependent on the hCG-induced activation of PI3K and PKC in cultured granulosa cells. Meanwhile, miR-181b and miR-222 suppressed RUNX1 and RUNX2 expression by targeting RUNX1 and RUNX2 3' untranslated regions (3'UTRs) with or without hCG, respectively. These results suggested that hCG-mediated miR-181b and miR-222 expression are important for the regulation of RUNX1 and RUNX2 expression levels in granulosa cells. To explore the specific functions of RUNX1 and RUNX2, we transfected RUNX1 and RUNX2 small interfering RNAs into primary cultured granulosa cells. Knockdown of RUNX1 and RUNX2 significantly decreased progesterone productions and the mRNA abundance of key steroidogenic enzymes (StAR, CYP11A1 and HSD3B) after hCG treatment. But only miR-222 increased estradiol secretion in goat granulosa cells. In addition, knockdown of RUNX1 and RUNX2 also promoted granulosa cell proliferation. The hormonally regulated expression of RUNX1 and RUNX2 in granulosa cells, their involvement in progesterone production, and promoted granulosa cell proliferation suggest important roles of RUNX1 and RUNX2 in follicular development and luteinization.

Augmented expression of RUNX1 deregulates the global gene expression of U87 glioblastoma multiforme cells and inhibits tumor growth in mice

Glioblastoma multiforme is the most common and aggressive primary brain tumor in adults. A mesenchymal phenotype was associated with tumor aggressiveness and poor prognosis in glioblastoma multiforme patients. Recently, the transcription factor RUNX1 was suggested as a driver of the glioblastoma multiforme mesenchymal gene expression signature; however, its independent role in this process is yet to be described. Here, we assessed the role of RUNX1 in U87 glioblastoma multiforme cells in correspondence to its mediated transcriptome and genome-wide occupancy pattern. Overexpression of RUNX1 led to diminished tumor growth in nude and severe combined immunodeficiency mouse xenograft tumor model. At the molecular level, RUNX1 occupied thousands of genomic regions and regulated the expression of hundreds of target genes, both directly and indirectly. RUNX1 occupied genomic regions that corresponded to genes that were shown to play a role in brain tumor progression and angiogenesis and upon overexpression led to a substantial down-regulation of their expression level. When overexpressed in U87 glioblastoma multiforme cells, RUNX1 down-regulated key pathways in glioblastoma multiforme progression including epithelial to mesenchymal transition, MTORC1 signaling, hypoxia-induced signaling, and TNFa signaling via NFkB. Moreover, master regulators of the glioblastoma multiforme mesenchymal phenotype including CEBPb, ZNF238, and FOSL2 were directly regulated by RUNX1. The data suggest a central role for RUNX1 as master regulator of gene expression in the U87 glioblastoma multiforme cell line and mark RUNX1 as a potential target for novel future therapies for glioblastoma multiforme.

RUNX transcription factors at the interface of stem cells and cancer

The RUNX1 transcription factor is a critical regulator of normal haematopoiesis and its functional disruption by point mutations, deletions or translocations is a major causative factor leading to leukaemia. In the majority of cases, genetic changes in RUNX1 are linked to loss of function classifying it broadly as a tumour suppressor. Despite this, several recent studies have reported the need for a certain level of active RUNX1 for the maintenance and propagation of acute myeloid leukaemia and acute lymphoblastic leukaemia cells, suggesting an oncosupportive role of RUNX1. Furthermore, in solid cancers, RUNX1 is overexpressed compared with normal tissue, and RUNX factors have recently been discovered to promote growth of skin, oral, breast and ovarian tumour cells, amongst others. RUNX factors have key roles in stem cell fate regulation during homeostasis and regeneration of many tissues. Cancer cells appear to have corrupted these stem cell-associated functions of RUNX factors to promote oncogenesis. Here, we discuss current knowledge on the role of RUNX genes in stem cells and as oncosupportive factors in haematological malignancies and epithelial cancers.

RUNX1 Regulates Migration, Invasion, and Angiogenesis via p38 MAPK Pathway in Human Glioblastoma

Runt-related transcription factor 1 (RUNX1) is essential for the establishment of fetal and adult hematopoiesis and neuronal development. Aberrant expression of RUNX1 led to proliferation and metastasis of several cancers. The aim of the present study was to investigate the role of RUNX1 in migration, invasion, and angiogenesis of human glioblastoma using IL-1β-treated U-87 MG human glioblastoma cells as a model. IL-1β at 10 ng/ml stimulated translocation of RUNX1 into the nucleus with increased expressions of RUNX1, MMP-1, MMP-2, MMP-9, MMP-19, and VEGFA in U-87 MG cells. In addition, silencing of RUNX1 gene significantly suppressed U-87 MG cell migration and invasion abilities. Moreover, knockdown of RUNX1 mRNA in U-87 MG cells reduced the tube formation of human umbilical vein endothelial cells. Further investigation revealed that IL-1β-induced RUNX1 expression might be mediated via the p38 mitogen-activated protein kinase (MAPK) signaling molecule for the expression of these invasion- and angiogenic-related molecules. Together with an inhibitor of p38 MAPK (SB203580) could decrease RUNX1 mRNA expression. Thus, RUNX1 may be one of the putative molecular targeted therapies against glioma metastasis and angiogenesis through the activation of p38 MAPK signaling pathway.

RUNX1 and FOXP3 interplay regulates expression of breast cancer related genes

Runx1 participation in epithelial mammary cells is still under review. Emerging data indicates that Runx1 could be relevant for breast tumor promotion. However, to date no studies have specifically evaluated the functional contribution of Runx1 to control gene expression in mammary epithelial tumor cells. It has been described that Runx1 activity is defined by protein context interaction. Interestingly, Foxp3 is a breast tumor suppressor gene. Here we show that endogenous Runx1 and Foxp3 physically interact in normal mammary cells and this interaction blocks Runx1 transcriptional activity. Furthermore we demonstrate that Runx1 is able to bind to R-spondin 3 (RSPO3) and Gap Junction protein Alpha 1 (GJA1) promoters. This binding upregulates Rspo3 oncogene expression and downregulates GJA1 tumor suppressor gene expression in a Foxp3-dependent manner. Moreover, reduced Runx1 transcriptional activity decreases tumor cell migration properties. Collectively, these data provide evidence of a new mechanism for breast tumor gene expression regulation, in which Runx1 and Foxp3 physically interact to control mammary epithelial cell gene expression fate. Our work suggests for the first time that Runx1 could be involved in breast tumor progression depending on Foxp3 availability.

Dopamine down-regulation of protein L-isoaspartyl methyltransferase is dependent on reactive oxygen species in SH-SY5Y cells

Parkinson's disease (PD) is a chronic and progressive neurological disorder that is characterized by the loss of dopaminergic neurons in the substantia nigra. Dopamine, via the oxidative stress that it generates in the cytosol, could contribute to the selective loss of neurons observed in PD. Protein L-isoaspartyl methyltransferase (PIMT) is an enzyme that repairs L-isoaspartyl-containing proteins and possesses anti-apoptotic properties. PIMT expression has been shown to decrease with age. Together, these observations prompted us to investigate whether dopamine can regulate PIMT expression in SH-SY5Y neuroblastoma cells. Here, we report that dopamine down-regulated PIMT at both gene and protein levels. The same inhibition of PIMT protein level was caused by the electron transport chain inhibitor, rotenone, which was accompanied, in both cases, by an increase in cell death and reactive oxygen species (ROS) production. In fact, pre-treatment with the antioxidant N-acetyl cysteine blocked PIMT dopamine-associated down-regulation. PCMT1 promoter mapping experiments allowed the identification of two regions that showed different sensitivity to DA action. A first region localized between 61 and 94bp upstream of transcription start site was very sensitive to dopamine inhibition while a second region between 41 and 61bp appeared more resistant to dopamine inhibitory effect. The inhibition of PCMT1 promoter activity was mediated by dopamine-induced ROS since it was prevented by the hydroxyl radical scavenger N,N'-dimethylthiourea. Conversely, H2O2 inhibited in a dose-dependent manner the transcriptional activity of PCMT1 promoter. Therefore, our findings identified new molecular mechanisms, cytosolic dopamine and its resulting ROS, as inhibitors of PIMT expression. This suggests that ROS generated from cytosolic dopamine could reduce both the PCMT1 gene promoter activity and the PIMT protein level thus decreasing its capacity to repair proteins involved in apoptosis and could contribute to neuronal cell death observed in PD.

Transcription factors Runx1 to 3 are expressed in the lacrimal gland epithelium and are involved in regulation of gland morphogenesis and regeneration

PURPOSE

Lacrimal gland (LG) morphogenesis and repair are regulated by a complex interplay of intrinsic factors (e.g., transcription factors) and extrinsic signals (e.g., soluble growth/signaling factors). Many of these interconnections remain poorly characterized. Runt-related (Runx) factors belong to a small family of heterodimeric transcription factors known to regulate lineage-specific proliferation and differentiation of stem cells. The purpose of this study was to define the expression pattern and the role of Runx proteins in LG development and regeneration.

METHODS

Expression of epithelial-restricted transcription factors in murine LG was examined using immunostaining, qRT-PCR, and RT(2)Profiler PCR microarrays. The role of Runx transcription factors in LG morphogenesis was studied using siRNA and ex vivo LG cultures. Expression of Runx transcription factors during LG regeneration was assessed using in vivo model of LG regeneration.

RESULTS

We found that Runx factors are expressed in the epithelial compartment of the LG; in particular, Runx1 was restricted to the epithelium with highest level of expression in ductal and centroacinar cells. Downregulation of Runx1 to 3 expression using Runx-specific siRNAs abolished LG growth and branching and our data suggest that Runx1, 2, and 3 are partially redundant in LG development. In siRNA-treated LG, reduction of branching correlated with reduction of epithelial proliferation, as well as expression of cyclin D1 and the putative epithelial progenitor cell marker cytokeratin-5. Runx1, Runx3, and cytokeratin-5 expression increased significantly in regenerating LG and there was modest increase in Runx2 expression during LG differentiation.

CONCLUSIONS

Runx1 and 2 are new markers of the LG epithelial lineage and Runx factors are important for normal LG morphogenesis and regeneration.

Genome-wide DNA methylation analysis of articular chondrocytes reveals a cluster of osteoarthritic patients

OBJECTIVE

Alterations in DNA methylation patterns have been found to correlate with several diseases including osteoarthritis (OA). The aim of this study was to identify, for the first time, the genome-wide DNA methylation profiles of human articular chondrocytes from OA cartilage and healthy control cartilage samples.

METHODS

DNA methylation profiling was performed using Illumina Infinium HumanMethylation27 in 25 patients with OA and 20 healthy controls. Subsequent validation was performed by genome-wide expression analysis using the Affymetrix Human Gene 1.1 ST array in an independent cohort of 24 patients with OA. Finally, the most consistent genes in both assays were amplified by quantitative reverse transcriptase PCR in a validation cohort of 48 patients using microfluidic real-time quantitative PCR. Appropriate bioinformatics analyses were carried out using R bioconductor software packages and qBase plus software from Biogazelle.

RESULTS

We found 91 differentially methylated (DM) probes, which permitted us to separate patients with OA from healthy controls. Among the patients with OA, we detected 1357 DM probes that identified a tight cluster of seven patients who were different from the rest. This cluster was also identified by genome-wide expression in which 450 genes were differentially expressed. Further validation of the most consistent genes in an independent cohort of patients with OA permitted us to identify this cluster, which was characterised by increased inflammatory processes.

CONCLUSIONS

We were able to identify a tight subgroup of patients with OA, characterised by an increased inflammatory response that could be regulated by epigenetics. The identification and isolation of this subgroup may be critical for the development of effective treatment and disease prevention.

RUNX family: Regulation and diversification of roles through interacting proteins

The Runt-related transcription factors (RUNX) belong to an ancient family of metazoan genes involved in developmental processes. Through multiple protein-interacting partners, RUNX proteins have been implicated in diverse signaling pathways and cellular processes. The frequent inactivation of RUNX genes in cancer indicates crucial roles for RUNX in tumor suppression. This review discusses the abilities of RUNX proteins, in particular RUNX3, to integrate oncogenic signals or environmental cues and to initiate appropriate tumor suppressive responses.

Deregulation of RAD21 and RUNX1 expression in endometrial cancer

Cohesins and cohesin-regulated genes are deregulated in numerous types of human cancer. However, data concerning their status and role in endometrial cancer are scarce. This study aimed to determine the clinical significance of double-strand-break repair protein rad21 homolog (RAD21) and runt-related transcription factor 1 (RUNX1) gene dosage and mRNA expression in endometrial cancer. RAD21 is a component of the cohesin complex, crucial for chromosome segregation and DNA repair. RUNX1 is the transcription factor implicated in RAD21 regulation. The study group included 144 endometrial cancer patients. RAD21 and RUNX1 expression profiles were measured by reverse-transcription quantitative PCR. RAD21 gene dosage was determined by quantitative PCR. RAD21 gene dosage was associated with RAD21 mRNA expression (ϱ=0.22; p=0.009). Furthermore, RAD21 expression strongly correlated with RUNX1 expression (ϱ=0.43; p<0.0000001). Increased RAD21 gene dosage correlated with more advanced tumor stage (p=0.021), higher grade (p=0.021), cervical involvement (p=0.01) and the absence of obesity (p=0.025), while RAD21 mRNA expression correlatd with cervical involvement (p=0.027). The mRNA expression of RAD21 and RUNX1 was found to be deregulated and co-dependent in endometrial cancer. RAD21 gene dosage is associated with unfavorable tumor characteristics. However, elucidating the role of these molecular markers in endometrial oncogenesis requires further investigation, including functional studies and survival analysis.