• Molecules and Cells
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• v.42 no.12
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• pp.836-839
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• 2019

A tumor is an abnormal mass of tissue that arises when cells divide more than they should or do not die when they should. The cellular decision regarding whether to undergo division or death is made at the restriction (R)-point. Consistent with this, an increasingly large body of evidence indicates that deregulation of the R-point decision-making machinery accompanies the formation of most tumors. Although the R-point decision is literally a matter of life and death for the cell, and thus critical for the health of the organism, it remains unclear how a cell chooses its own fate. Recent work demonstrated that the R-point constitutes a novel oncogene surveillance mechanism operated by R-point-associated complexes of which RUNX3 and BRD2 are the core factors (Rpa-RX3 complexes). Here, we show that not only RUNX3 and BRD2, but also other members of the RUNX and BRD families (RUNX1, RUNX2, BRD3, and BRD4), are involved in R-point regulation.

• Journal of Nutrition and Health
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• v.51 no.1
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• pp.23-30
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• 2018

Purpose: Runx2 (runt-related transcription factor 2), a bone-specific transcription factor, is a key regulator of osteoblast differentiation and its expression is induced by the activation of BMP-2 signaling. This study examined whether zinc modulates BMP-2 signaling and therefore stimulates Runx2 and osteoblast differentiation gene expression. Methods: Two osteoblastic MC3T3-E1 cell lines (subclones 4 as a high osteoblast differentiation and subclone 24 as a low osteoblastic differentiation) were cultured in an osteogenic medium (OSM) as the normal control, Zn-($1{\mu}M$ Zn) or Zn+($15{\mu}M$ Zn) for 24 h. The genes and proteins for BMP-2 signaling (BMP-2, Smad-1/p-Smad-1), transcription factors (Runx2, osterix), and osteoblast differentiation marker proteins were assessed. Results: In both cell lines, BMP-2 mRAN and protein expression and extracellular BMP-2 secretion all decreased in Zn-. The expression of Smad-1 (downstream regulator of BMP-2 signaling) and p-Smad-1 (phosphorylated Smad-1) also downregulated in Zn-. Furthermore, the expression of the bone-specific transcription factors, Runx2 and osterix, decreased in Zn-, which might be due to the decreased BMP-2 expression and Smad-1 activation (p-Smad-1) by Zn-, because Runx2 and osterix both are downstream in BMP-2 signaling. Bone marker gene expression, such as alkaline phosphatase (ALP), collagen type I (COLI), osteocalcin, and osteopontin were also downregulated in Zn-. Conclusion: The results suggest that a zinc deficiency in osteoblasts suppresses the BMP-2 signaling pathway via the suppression of Smad-1 activation, and this suppressed BMP-2 signaling can cause poor osteoblast differentiation.

• Molecules and Cells
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• v.26 no.5
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• pp.459-461
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• 2008

Much research evidence supports the hypothesis that chronic, low-grade inflammation related to innate immunity may play an important role in the pathophysiology of type 2 diabetes mellitus (T2DM). Runt-related transcription factor 2 (RUNX2; MIM# 600211) acts as a scaffold that controls the integration, organization, and assembly of nucleic acids. To examine whether the novel promoter variant in RUNX2 is associated with the risk of T2DM and related phenotypes, RUNX2-742G > T was genotyped in 378 T2DM patients and 382 normal controls recruited in the Korean T2DM Study. Statistical analysis revealed that RUNX2-742G > T was associated with serum triglyceride level (TG) in nondiabetic controls, although it was not associated with the risk of T2DM. Individuals who carry T/T, T/G, and G/G genotypes had the highest ($2.061{\pm}0.20$), intermediate ($2.01{\pm}0.19$), and the lowest ($1.97{\pm}0.18$) levels of log [TG (mmol/l)] (P = 0.007), respectively. Our data on this important variant of RUNX2 suggest that lipid metabolism might be affected by genetic polymorphisms in the promoter region.

• Molecules and Cells
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• v.43 no.2
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• pp.126-138
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• 2020

The transcription factor RUNX1 first came to prominence due to its involvement in the t(8;21) translocation in acute myeloid leukemia (AML). Since this discovery, RUNX1 has been shown to play important roles not only in leukemia but also in the ontogeny of the normal hematopoietic system. Although it is currently still challenging to fully assess the different parameters regulating RUNX1 dosage, it has become clear that the dose of RUNX1 can greatly affect both leukemia and normal hematopoietic development. It is also becoming evident that varying levels of RUNX1 expression can be used as markers of tumor progression not only in the hematopoietic system, but also in non-hematopoietic cancers. Here, we provide an overview of the current knowledge of the effects of RUNX1 dosage in normal development of both hematopoietic and epithelial tissues and their associated cancers.

• BMB Reports
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• v.47 no.8
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• pp.463-468
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• 2014

Osteoblasts are specialized mesenchymal cells that are responsible for bone formation. In this study, we examine the role of GATA4 in osteoblast differentiation. GATA4 was abundantly expressed in preosteoblast cells and gradually down-regulated during osteoblast differentiation. Overexpression of GATA4 in osteoblastic cells inhibited alkaline phosphatase activity and nodule formation in osteogenic conditioned cell culture system. In addition, overexpression of GATA4 attenuated expression of osteogenic marker genes, including Runx2, alkaline phosphatase, bone sialoprotein, and osteocalcin, all of which are important for osteoblast differentiation and function. Overexpression of GATA4 attenuated Runx2 promoter activity, whereas silencing of GATA4 increased Runx2 induction. We found that GATA4 interacted with Dlx5 and subsequently decreased Dlx5 binding activity to Runx2 promoter region. Our data suggest that GATA4 acts as a negative regulator in osteoblast differentiation by downregulation of Runx2.

• Journal of Gastric Cancer
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• v.7 no.4
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• pp.185-192
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• 2007

Purpose: RUNX3, a novel tumor suppressor, is frequently inactivated in gastric cancer. In the present study, we examined the pattern of RUNX3 expression in gastric cancer cells from gastric cancer specimens and the impact of its alteration on clinical outcome. Materials and Methods: A total of 124 samples of both gastric cancer and normal tissue were obtained from 124 patients who underwent curative gastrectomy at the Seoul Medical Center from January 2001 to December 2005. RUNX3 expression was determined by immunohistochemical staining, and the results were analyzed. Statistical analysis wabased on clinicopathological findings and differences in survival rates. Results: The mean age of the patients was 61 years, and the male:female ratio was 1.9:1. The expression rate of RUNX3 was 59.7% (74/124). The expression rate was higher in differentiated gastric cancers (nucleus: 9.1%, cytoplasm: 57.6%) than in the undifferentiated types (nucleus: 5.2%, cytoplasm: 46.6%) (P=0.133). The 5-year survival rates according to RUNX3 expression determined from cancer tissue were 88.9% for the nucleus $\pm$ cytoplasm(+) group of patients, 76.1% for the cytoplasm only (+) group of patients, and 65.3% for the RUNX3 negative expression group of patients (P=0.626). Only UICC TNM staging showed statistical significance related to the survival rate, as determined by multivariate analysis. Conclusion: The RUNX3 expression rate was higher in differentiated gastric cancer than in the undifferentiated types without significance. Although RUNX3 expression predicted better survival, based on multivariate analysis, the finding was not statistically significant. More cases should be further evaluated.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3773-3778
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• 2013

Increased oxidative stress and changes in DNA methylation are frequently detected in bladder cancer patients. We previously demonstrated a relationship between increased oxidative stress and hypomethylation of the transposable long-interspersed nuclear element-1 (LINE-1). Promoter hypermethylation of a tumor suppressor gene, runt-related transcription factor 3 (RUNX3), may also be associated with bladder cancer genesis. In this study, we investigated changes of DNA methylation in LINE-1 and RUNX3 promoter in a bladder cancer cell (UM-UC-3) under oxidative stress conditions, stimulated by challenge with $H_2O_2$ for 72 h. Cells were pretreated with an antioxidant, tocopheryl acetate for 1 h to attenuate oxidative stress. Methylation levels of LINE-1 and RUNX3 promoter were measured by combined bisulfite restriction analysis PCR and methylation-specific PCR, respectively. Levels of LINE-1 methylation were significantly decreased in $H_2O_2$-treated cells, and reestablished after pretreated with tocopheryl acetate. Methylation of RUNX3 promoter was significantly increased in cells exposed to $H_2O_2$. In tocopheryl acetate pretreated cells, it was markedly decreased. In conclusion, hypomethylation of LINE-1 and hypermethylation of RUNX3 promoter in bladder cancer cell line was experimentally induced by reactive oxygen species (ROS). The present findings support the hypothesis that oxidative stress promotes urothelial cell carcinogenesis through modulation of DNA methylation. Our data also imply that mechanistic pathways of ROS-induced alteration of DNA methylation in a repetitive DNA element and a gene promoter might differ.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.4
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• pp.409-415
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• 2019

Cleidocranial dysplasia (CCD) is an autosomal-dominant disease characterized by the delayed closure of cranial sutures, defects in clavicle formation, supernumerary teeth, and delayed tooth eruption. Defects in the Runt-related transcription factor 2 (RUNX2), a master regulator of bone formation, have been identified in CCD patients. The aim of this study was to identify the molecular genetic causes in a CCD family with delayed tooth eruption. The 23-year-old female proband and her mother underwent clinical and radiographic examinations, and all coding exons of the RUNX2 were sequenced. Mutational analysis revealed a single nucleotide deletion mutation (NM_001024630.4 : c.357delC) in exon 3 in the proband and her mother. The single C deletion would result in a frameshift in translation and introduce a premature stop codon [p.(Asn120Thrfs^*24)]. This would result in the impaired function of RUNX2 protein, which may be the cause of delayed eruption of permanent teeth in the family.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.4
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• pp.381-385
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• 2007

Bone is a dynamic organ that bone remodeling occurs throughout life and involves the process in which the bone matrix is broken down through resorption by osteoclasts and then built back again through bone formation by osteoblasts. Usually these two processes balance each other and a stable level of bone mass is maintained. We here discuss transcription factors involved in regulating the osteoblast differentiation pathway. Runx2 is a transcription factor which is essential in skeletal development by regulating osteoblast differentiation and chondrocyte maturation. Its companion subunit, Cbf${\beta}$ is needed for an early step in osteoblast differentiation pathway. Whereas Osterix(Osx) is a new identified osteoblast-specific transcription factor which is required for the differentiation of preosteoblasts into more mature and functional osteoblasts. We also discuss other transcription factors, Msx1 and 2, Dlx5 and 6, Twist, and Sp3 that affect skeletal patterning and development. Understanding the characteristics of mice in which these transcription factors are inactivated should help define their role in bone physiology and pathology of bone defects.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.3
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• pp.314-319
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• 2017

Chlorogenic acid, a well-known polyphenol, and its derivatives, ester of caffeic acid on quinic acid moiety, are abundant in coffee, tea, fruits, and various vegetables. This study examined the effects of cryptochlorogenic acid (CCA) on osteoblast differentiation. CCA-induced mRNA expression levels of osteogenic genes in MC3T3E1 and C3H10T1/2 cells were determined by RT-PCR and qPCR. CCA regulated expression of key osteogenic genes in the early stage of differentiation, including distal-less homeobox 5 (Dlx5), DNA-binding protein inhibitor (Id1), and runt-related transcription factor 2 (Runx2). These results suggest that CCA may enhance osteoblast differentiation through expression of osteogenic genes such as Id1, Dlx5, and Runx2, especially in the early stage.