RUNX: a trilogy of cancer genes

RUNX3 exerts tumor-suppressive role through inhibiting EXOSC4 expression

Breast cancer severely affects women health. 70% of breast cancer are estrogen receptor positive. Breast cancer stem cells are a group of tumor with plasticity, causing tumor relapse and metastasis. RUNX3 is a tumor suppressor frequently inactivated in estrogen receptor positive breast cancer. However, the mechanism of how RUNX3 is involved in the regualation of cancer stem cell traits in estrogen receptor positive breast cancer remains elusive. In this study, we utilized cut-tag assay to investigate the binding profile RUNX3 in BT474 and T47D cell, and confirmed EXOSC4 as the bona-fide target of RUNX3; RUNX3 could bind to the promoter are of EXOSC4 to suppress its expression. Furthermore, EXOSC4 could increase the colony formation, cell invasion and mammosphere formation ability of breast cancer cells and upregulate the the expression of SOX2 and ALDH1. Consistent with these findings, EXOSC4 was associated with poorer survival for Luminal B/Her2 breast cancer patiens. At last, we confirmed that EXOSC4 mediated the tumor suppressive role of RUNX3 in breast cancer cells. In conclusion, we demonstrate that RUNX3 directly binds to the promoter region of EXOSC4, leading to the suppression of EXOSC4 expression and exerting a tumor-suppressive effect in estrogen receptor postivive breast cancer cells.

Multiple Roles of the RUNX Gene Family in Hepatocellular Carcinoma and Their Potential Clinical Implications

Hepatocellular carcinoma (HCC) is one of the most frequent cancers in humans, characterised by a high resistance to conventional chemotherapy, late diagnosis, and a high mortality rate. It is necessary to elucidate the molecular mechanisms involved in hepatocarcinogenesis to improve diagnosis and treatment outcomes. The Runt-related (RUNX) family of transcription factors (RUNX1, RUNX2, and RUNX3) participates in cardinal biological processes and plays paramount roles in the pathogenesis of numerous human malignancies. Their role is often controversial as they can act as oncogenes or tumour suppressors and depends on cellular context. Evidence shows that deregulated RUNX genes may be involved in hepatocarcinogenesis from the earliest to the latest stages. In this review, we summarise the topical evidence on the roles of RUNX gene family members in HCC. We discuss their possible application as non-invasive molecular markers for early diagnosis, prognosis, and development of novel treatment strategies in HCC patients.

Crosstalk between protein kinase C α and transforming growth factor β signaling mediated by Runx2 in intestinal epithelial cells

Tight coordination of growth regulatory signaling is required for intestinal epithelial homeostasis. Protein kinase C α (PKCα) and transforming growth factor β (TGFβ) are negative regulators of proliferation with tumor suppressor properties in the intestine. Here, we identify novel crosstalk between PKCα and TGFβ signaling. RNA-Seq analysis of nontransformed intestinal crypt-like cells and colorectal cancer cells identified TGFβ receptor 1 (TGFβR1) as a target of PKCα signaling. RT-PCR and immunoblot analysis confirmed that PKCα positively regulates TGFβR1 mRNA and protein expression in these cells. Effects on TGFβR1 were dependent on Ras-extracellular signal-regulated kinase 1/2 (ERK) signaling. Nascent RNA and promoter-reporter analysis indicated that PKCα induces TGFβR1 transcription, and Runx2 was identified as an essential mediator of the effect. PKCα promoted ERK-mediated activating phosphorylation of Runx2, which preceded transcriptional activation of the TGFβR1 gene and induction of Runx2 expression. Thus, we have identified a novel PKCα→ERK→Runx2→TGFβR1 signaling axis. In further support of a link between PKCα and TGFβ signaling, PKCα knockdown reduced the ability of TGFβ to induce SMAD2 phosphorylation and cell cycle arrest, and inhibition of TGFβR1 decreased PKCα-induced upregulation of p21^Cip1 and p27^Kip1 in intestinal cells. The physiological relevance of these findings is also supported by The Cancer Genome Atlas data showing correlation between PKCα, Runx2, and TGFβR1 mRNA expression in human colorectal cancer. PKCα also regulated TGFβR1 in endometrial cancer cells, and PKCα, Runx2, and TGFβR1 expression correlates in uterine tumors, indicating that crosstalk between PKCα and TGFβ signaling may be a common mechanism in diverse epithelial tissues.

PPP1R7 Is a Novel Translocation Partner of CBFB via t(2;16)(q37;q22) in Acute Myeloid Leukemia

In a subset of acute myeloid leukemia (AML) cases, the core binding factor beta subunit gene (CBFB) was rearranged via inv(16)(p13.1q22) or t(16;16)(p13.1;q22), in which the smooth muscle myosin heavy chain 11 gene (MYH11) was the partner (CBFB::MYH11). Rare variants of CBFB rearrangement occurring via non-classic chromosomal aberrations have been reported, such as t(1;16), t(2;16), t(3;16), t(5;16), and t(16;19), but the partners of CBFB have not been characterized. We report a case of AML with a complex karyotype, including t(2;16)(q37;q22), in which the protein phosphatase 1 regulatory subunit 7 gene (PPP1R7) at chromosome 2q37 was rearranged with CBFB (CBFB::PPP1R7). This abnormality was inconspicuous by conventional karyotype and interphase fluorescence in situ hybridization (FISH), thus leading to an initial interpretation of inv(16)(p13.1q22); however, metaphase FISH showed that the CBFB rearrangement involved chromosome 2. Using whole genome and Sanger sequencing, the breakpoints were identified as being located in intron 5 of CBFB and intron 7 of PPP1R7. A microhomology of CAG was found in the break and reconnection sites of CBFB and PPP1R7, thus supporting the formation of CBFB::PPP1R7 by microhomology-mediated end joining.

Molecular Basis of Hematological Disease Caused by Inherited or Acquired RUNX1 Mutations

The transcription factor RUNX1 is essential for correct hematopoietic development; in its absence in the germ line, blood stem cells are not formed. RUNX1 orchestrates dramatic changes in the chromatin landscape at the onset of stem cell formation, which set the stage for both stem self-renewal and further differentiation. However, once blood stem cells are formed, the mutation of the RUNX1 gene is not lethal but can lead to various hematopoietic defects and a predisposition to cancer. Here we summarize the current literature on inherited and acquired RUNX1 mutations, with a particular emphasis on mutations that alter the structure of the RUNX1 protein itself, and place these changes in the context of what is known about RUNX1 function. We also summarize which mutant RUNX1 proteins are actually expressed in cells and discuss the molecular mechanism underlying how such variants reprogram the epigenome setting stem cells on the path to malignancy.

Biofabrication of poly(l-lactide-co-ε-caprolactone)/silk fibroin scaffold for the application as superb anti-calcification tissue engineered prosthetic valve

In this study, electrospun scaffolds were fabricated by blending poly(l-lactide-co-ε-caprolactone) (PLCL) and silk fibroin (SF) with different ratios, and further the feasibility of electrospun PLCL/SF scaffolds were evaluated for application of tissue engineered heart valve (TEHV). Scanning electron microscopy (SEM) results showed that the surface of PLCL/SF electrospun scaffolds was smooth and uniform while the mechanical properties were appropriate as valve prosthesis. In vitro cytocompatibility evaluation results demonstrated that all of the PLCL/SF electrospun scaffolds were cytocompatible and valvular interstitial cells (VICs) cultured on PLCL/SF scaffolds of 80/20 & 70/30 ratios exhibited the best cytocompatibility. The in vitro osteogenic differentiation of VICs including alkaline phosphatase (ALP) activity and quantitative polymerase chain reaction (qPCR) assays indicated that PLCL/SF scaffolds of 80/20 & 90/10 ratios behaved better anti-calcification ability. In the in vivo calcification evaluation model of rat subdermal implantation, PLCL/SF scaffolds of 80/20 & 90/10 ratios presented better anti-calcification ability, which was consistent with the in vitro results. Moreover, PLCL/SF scaffolds of 80/20 & 70/30 ratios showed significantly enhanced cell infiltration and M2 macrophage with higher CD206+/CD68+ ratio. Collectively, our data demonstrated that electrospun scaffolds with the PLCL/SF ratio of 80/20 hold great potential as TEHV materials.

Methylation study of the Paris system for reporting urinary (TPS) categories

AIMS

Bladder EpiCheck is one of several urinary tests studied to identify bladder tumours and analyses 15 methylation biomarkers determining bladder cancer presence on the basis of methylation profile.

METHODS

374 patients diagnosed with high-grade non-muscle invasive bladder cancer were treated and followed for 1 year with voided urine cytology and white-light cystoscopy and biopsies according to European Association of Urology Guidelines. 268 cases were diagnosed with high-grade papillary carcinoma, while 106 cases were carcinoma in situ. Bladder EpiCheck test was performed together with cytology in all cases.

RESULTS

Comparing cytological categories of negative for high-grade urothelial carcinoma (NHGUC) and atypical urothelial cells (AUCs), we found that an EpiScore <60 correlates with NHGUC (p=0.0003, Fisher's exact test), while comparing AUC and suspicious for high-grade urothelial carcinoma (SHGUC) or SHGUC and high-grade urothelial carcinoma (HGUC) categories, an EpiScore ≥60 correlates with SHGUC and HGUC, respectively (p=0.0031 and p=0.0027, Fisher's exact test). In each TPS category, we found that sensitivity, specificity, Positive Predicitve Value (PPV) and Negative Predictive Value (NPV) of the Bladder EpiCheck test in HGUC category were higher than those observed in SHGUC group (sensitivity=98%, specificity=100%, NPV=85.7%, PPV=100% vs sensitivity=86.6%, specificity=52.3%, NPV=84.6%, PPV=56.5%).

CONCLUSIONS

Analysing methylation study results, we demonstrated that different TPS cytological categories also carry a distinct molecular signature. Moreover, our results confirm that cytological categories SHGUC and HGUC are different entities also from a molecular point of view and should continue to represent distinct groups in TPS.

Transcriptome changes induced by RUNX3 in cervical cancer cells in vitro

Runt-related transcription factor 3 (RUNX3) is a member of Runt domain family that is known to play key roles in various different types of tumor. It was recently demonstrated that RUNX3 may also be associated with cervical cancer. The aim of the present study was to investigate the potential association between transcriptome changes and RUNX3 expression in cervical cancer. A RUNX3 overexpression model was constructed using cervical cancer cell lines by RUNX3 plasmid transfection. It was demonstrated that the upregulated expression of RUNX3 inhibited proliferation of cervical cancer cell lines, particularly SiHa cells, and was associated with the expression of the IL-6, PTGS2, FOSL1 and TNF genes. In addition, it was revealed that the TNF and FoxO pathways may also be affected by RUNX3. Therefore, the expression of the RUNX3 gene may be involved in the occurrence and progression of cervical cancer.

Circulating methylated RUNX3 and SFRP1 genes as a noninvasive panel for early detection of colorectal cancer

OBJECTIVE

This study was conducted to assess the methylation status of runt-related transcription factor 3 (RUNX3) and secreted frizzled-related protein 1 (SFRP1) genes in paired tissue and serum samples of colorectal cancer (CRC), adenomatous, and control subjects and elucidate the association between methylation status on RUNX3 and SFRP1 mRNA expression.

METHODS

Methylation status of RUNX3 and SFRP1 in paired tissue and serum samples and RUNX3 and SFRP1 mRNA expression in tissue from 85 patients with CRC, 40 with adenoma, and 40 healthy controls were determined using methylation-specific PCR and reverse transcription PCR.

RESULTS

The frequency RUNX3 and SFRP1 genes methylation was significantly higher in both tissues and serum of CRC patients and was significantly associated with absence of its corresponding mRNA expression. The concordance between tissue and serum methylation status was 94.4% for RUNX3 and 94.3% for SFRP1. Tissue RUNX3 methylation status detected CRC with 63.53% sensitivity and 80.00% specificity, while serum RUNX3 methylation status detected CRC with 60.00% sensitivity and 82.50% specificity. Tissue SFRP1 methylation status showed a sensitivity of 82.35% and specificity of 65.00%, while serum SFRP1 methylation status showed a sensitivity of 77.65% and specificity of 70.00% in detection of CRC. RUNX3/SFRP1/carcinoembryonic antigen (CEA) panel identified CRC with sensitivity of 89.41% in tissue and 84.71% in serum.

CONCLUSION

Our results verified the reliability of using serum RUNX3 and SFRP1 methylation status as a noninvasive biomarker for diagnosis of CRC and that combined detection of RUNX3/SFRP1/CEA panel might be a promising strategy for early detection of CRC.

Prognostic DNA Methylation Biomarkers in High-risk Non-muscle-invasive Bladder Cancer: A Systematic Review to Identify Loci for Prospective Validation

CONTEXT

High-risk non-muscle-invasive bladder cancer (HR-NMIBC) represents over 30% of all incident urothelial bladder cancers (BCs); patients are at risk of progression, and 20-30% will die from BC within 5 yr. Current guidelines recommend induction and maintenance of intravesical bacillus Calmette-Guérin (BCG) or upfront radical cystectomy for highest-risk disease, treatments with markedly different morbidity, mortality, and patient burden. There are no validated biomarkers to facilitate such treatment decisions. Alterations in DNA methylation are commonplace in BC; hence, measurable changes in DNA methylation represent an opportunity for the discovery of such biomarkers.

OBJECTIVE

To systematically assess the evidence regarding DNA methylation markers as prognosticators for HR-NMIBC.

EVIDENCE ACQUISITION

Standard systematic review methods were employed with searches undertaken in MEDLINE, EMBASE, and PubMed up to January 2019. Studies that included patients with HR-NMIBC and investigated the utility of DNA methylation biomarkers as prognostic tools were included.

EVIDENCE SYNTHESIS

Of 63 prognostic biomarker studies identified, 21 met the protocol-driven inclusion criteria and were directly relevant to HR-NMIBC patient outcomes: tumour recurrence (TR), tumour progression (TP), disease-specific survival (DSS), and overall survival (OS). These studies described 140 methylation markers; of these, the most promising were cadherin-13 (CDH13; hazard ratios [HRs]: 5.1 for TR, 6.6 for TP, 3.8-8.0 for OS), protocadherins (PCDHs; HRs: 4.7 for TR, 2.5 for TP, 3.0-4.8 for OS), Runt domain transcription factor 3 (RUNX3; HR: 5.1 for TP), Homeobox 9 (HOXA9; HR: 1.9 for TR), Islet-1 (ISL1; HRs: 1.7 for TR, 3.3 for TP), and PAX6 (HR: 2.2 for TR).

CONCLUSIONS

This systematic review identifies a number of potentially useful prognostic methylation markers for HR-NMIBC. These loci (CDH13, PCDHs, RUNX3, HOXA9, ISL1, and PAX6) should be validated in prospective studies in order to translate benefit to patients.

PATIENT SUMMARY

Early bladder cancer represents a more complex spectrum of disease than can be assessed by conventional methods Emerging studies on molecular markers will improve our understanding of this disease, and may enable more precise and personalised treatment.

Genome-wide analysis of DNA methylation in bronchial washings

Background

The objective of this study was to discover DNA methylation biomarkers for detecting non-small lung cancer (NSCLC) in bronchial washings and understanding the association between DNA methylation and smoking cessation.

Methods

DNA methylation was analyzed in bronchial washing samples from 70 NSCLCs and 53 hospital-based controls using Illumina HumanMethylation450K BeadChip. Methylation levels in these bronchial washings were compared to those in 897 primary lung tissues of The Cancer Genome Atlas (TCGA) data.

Results

Twenty-four CpGs (p < 1.03E−07) were significantly methylated in bronchial washings from 70 NSCLC patients compared to those from 53 controls. The CpGs also had significant methylation in the TCGA cohort. The 123 participants were divided into a training set (N = 82) and a test set (N = 41) to build a classification model. Logistic regression model showed the best performance for classification of lung cancer in bronchial washing samples: the sensitivity and specificity of a marker panel consisting of seven CpGs in TFAP2A, TBX15, PHF11, TOX2, PRR15, PDGFRA, and HOXA11 genes were 87.0 and 83.3% in the test set, respectively. The area under the curve (AUC) was equal to 0.87 (95% confidence interval = 0.73–0.96, p < 0.001). Methylation levels of two CpGs in RUNX3 and MIR196A1 genes were inversely associated with duration of smoking cessation in the controls, but not in NSCLCs, after adjusting for pack-years of smoking.

Conclusions

The present study suggests that NSCLC may be detected by analyzing methylation changes of seven CpGs in bronchial washings. Furthermore, smoking cessation may lead to decreased DNA methylation in nonmalignant bronchial epithelial cells in a gene-specific manner.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0498-8) contains supplementary material, which is available to authorized users.

Chemoresistance‑related long non‑coding RNA expression profiles in human breast cancer cells

Breast cancer is the most commonly diagnosed cancer and the leading cause of cancer death in females worldwide. Chemoresistance has been a major reason for the drug therapy failure. The present study performed a microarray analysis between MCF-7 and MCF-7/adriamycin (ADR) cells, and intended to identify long non-coding (lnc)RNA expression character in drug resistant breast cancer cells. MCF-7/ADR cells were induced from MCF-7 cells via pulse-selection with doxorubicin for 4 weeks, and the resistance to doxorubicin of ADR cells was confirmed by MTT assay. Microarray analysis was performed between MCF-7 and MCF-7/ADR cells. Total RNA was extracted from the two cell lines respectively and was transcribed into cDNA. The results of the microarray were verified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Gene Ontology (GO) and pathways analysis were conducted to enrich the dysregulated lncRNAs presented in the microarray results. Compared to the MCF-7 cells, 8,892 lncRNAs were differentially expressed in MCF/ADR cells (absolute fold-change >2.0). A total of 32 lncRNAs were selected for RT-qPCR by fold-change filtering, standard Student's t-test, and multiple hypothesis testing. Among the dysregulated lncRNAs, AX747207 was prominent because its associated gene RUNX3 was previously reported to be relative to malignant tumor chemoresistance. GO analysis results also indicated some biological processes and molecular functions linked to chemoresistance. The pathway enrichment results provided some potential pathways associated with chemoresistance. In the present study, the authors intended to identify lncRNA expression character in drug resistant cell line MCF-7/ADR, corresponding to the parental MCF-7 cell line. In addition, the study identified the lncRNA AX747207, and its potential targeted gene RUNX3, may be related to chemoresistance in breast cancer. These results may new insights into exploring the mechanisms of chemoresistance in breast cancer.

DNA methylation affects metastasis of renal cancer and is associated with TGF-β/RUNX3 inhibition

Background

Renal cell carcinoma accounts for 2–3% of all cancers and metastasis increased the malignancy of renal cancer. However, the role of methylation in metastasis of renal cancer is poorly understood.

Methods

We performed targeted gene array to compare the differential expressions of methylation regulated genes in metastatic and primary renal cancer tissues. Quantitative methylation specific PCR was performed to examine the CpG methylation levels of Runt related transcription factor 3 (RUNX3) and transforming growth factor (TGF)-β. Western blot was performed to detect the expression of target genes. Murine xenograft renal cancer model was established to assay gene expression, methylation level, tumor growth and animal survival in vivo.

Results

RUNX3 and TGF-β levels were decreased in metastatic renal cancer tissues as a result of their CpG methylation. Metastatic xenograft model displayed decreased expression levels of RUNX3 and TGF-β and higher CpG methylation levels, bigger tumor size and shorter survival time, all which were restored by treatment with a methylation inhibitor.

Conclusions

Hypermethylation in CpG islands promotes metastasis of renal cancer and is associated with TGF-β and RUNX3 inhibition.

Electronic supplementary material

The online version of this article (10.1186/s12935-018-0554-7) contains supplementary material, which is available to authorized users.

RUNX3 regulates renal cell carcinoma metastasis via targeting miR-6780a-5p/E-cadherin/EMT signaling axis

Runt-related transcription factor 3 (RUNX3) is a tumor suppressor in many human solid tumors. In this study, renal cell carcinoma (RCC) microarray analysis showed that the level of RUNX3 expression was lower in RCC tissue than in adjacent normal renal tissues, and was correlated with depth of invasion (pT stage) (P<0.001) and Tumor Node Metastasis (TNM) stage (P<0.001). RUNX3 expression was negatively correlated with poor 5-year overall and disease-free patient survival. RUNX3 suppressed RCC metastasis and invasion and increased levels of E-cadherin, an important marker of epithelial-mesenchymal transition, in vitro and in vivo. RUNX3 also inhibited microRNA-6780a-5p, which directly targeted the E-cadherin 3'untranslated region and decreased its expression. We confirmed that miR-6780a-5p mimics abrogated RUNX3-mediated E-cadherin upregulation and RCC metastasis/invasion inhibition. Thus, RUNX3 targeted the miR-6780a-5p/E-cadherin/EMT signaling axis to suppress renal carcinoma cell migration and invasion. This pathway illustrates a new RUNX3 function and provides potential targets for the treatment of RUNX3 mutant and loss-of-function RCC tumors. RUNX3 may also act as an effective prognostic indicator in RCC.

An early biomarker and potential therapeutic target of RUNX 3 hypermethylation in breast cancer, a system review and meta-analysis

Runt-related transcription factor 3 (RUNX3) methylation plays an important role in the carcinogenesis of breast cancer (BC). However, the association between RUNX3 hypermethylation and significance of BC remains under investigation. The purpose of this study is to perform a meta-analysis and literature review to evaluate the clinicopathological significance of RUNX3 hypermethylation in BC. A comprehensive literature search was performed in Medline, Web of Science, EMBASE, Cochrane Library Database, CNKI and Google scholar. A total of 10 studies and 747 patients were included for the meta-analysis. Pooled odds ratios (ORs) with corresponding confidence intervals (CIs) were evaluated and summarized respectively. RUNX3 hypermethylation was significantly correlated with the risk of ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC), OR was 50.37, p < 0.00001 and 22.66, p < 0.00001 respectively. Interestingly, the frequency of RUNX3 hypermethylation increased in estrogen receptor (ER) positive BC, OR was 12.12, p = 0.005. High RUNX3 mRNA expression was strongly associated with better relapse-free survival (RFS) in BC patients. In summary, RUNX3 methylation could be a promising early biomarker for the diagnosis of BC. High RUNX3 mRNA expression is correlated to better RFS in BC patients. RUNX3 could be a potential therapeutic target for the development of personalized therapy.

Runx3 plays a critical role in restriction-point and defense against cellular transformation

The restriction (R)-point decision is fundamental to normal differentiation and the G₁-S transition, and the decision-making machinery is perturbed in nearly all cancer cells. The mechanisms underlying the cellular context-dependent R-point decision remain poorly understood. We found that the R-point was dysregulated in Runx3^-/-mouse embryonic fibroblasts (MEFs), which formed tumors in nude mice. Ectopic expression of Runx3 restored the R-point and abolished the tumorigenicity of Runx3^-/-MEFs and K-Ras-activated Runx3^-/-MEFs (Runx3^-/-;K-Ras^G12D/+). During the R-point, Runx3 transiently formed a complex with pRb and Brd2 and induced Cdkn1a (p21^{Waf1/Cip1/Sdi1}; p21), a key regulator of the R-point transition. Cyclin D-CDK4/6 promoted dissociation of the pRb-Runx3-Brd2 complex, thus turning off p21 expression. However, cells harboring oncogenic K-Ras maintained the pRb-Runx3-Brd2 complex and p21 expression even after introduction of Cyclin D1. Thus, Runx3 plays a critical role in R-point regulation and defense against cellular transformation.

Runx3 inhibits melanoma cell migration through regulation of cell shape change

The transcription factor Runx3 is a known tumor suppressor gene, and its expression is frequently lost in melanoma. However, the potential contribution of the loss of Runx3 expression to melanoma development and progression remains unclear. In this in vitro study, we demonstrated that ectopic Runx3 re-expression in B16-F10 melanoma cells changed the cell shape from elongated and branched to spread and unbranched, which enhanced stress fiber formation, increased the number of mature and fibrillar focal adhesions, and up-regulated fibronectin expression. In association with the cell shape change, the Runx3 re-expression in B16-F10 melanoma cells inhibited cell migration. Moreover, the phenotype of the Runx3 induced cell shape change was partially resembled when the melanoma cells were cultured on a fibronectin-coated coverslip, suggesting that fibronectin may mediate the Runx3 induced cell shape change of the melanoma cells. Taken together, our findings suggest that Runx3 may regulate cell shape to inhibit melanoma cell migration partly through enhancing stress fiber formation and ECM protein production. Our present study provides further evidence for the idea that cell shape change is potentially correlated with melanoma development and progression.

RUNX3 regulates hepatocellular carcinoma cell metastasis via targeting miR-186/E-cadherin/EMT pathway

Runt-related transcription factor 3 (RUNX3) has been reported as a tumor suppressor in some kinds of cancers. In the present study, hepatocellular carcinoma (HCC) microarray analysis showed that RUNX3 expression was significantly lower in HCC tissues compared with that in adjacent non-tumor tissues, and was negatively associated with metastasis and TNM stage. RUNX3 was an independently prognostic factor for 5-year overall and disease-free patient survival. Mechanically, RUNX3 repressed metastasis and invasion of HCC, and increased E-cadherin expression. RUNX3 also repressed microRNA-186 to increase E-cadherin expression. We demonstrated that miR-186 mimics attenuated RUNX3-induced increase of E-cadherin and inhibition of metastasis and invasion. In conclusion, RUNX3 suppressed HCC cell migration and invasion by targeting the miR-186/E-cadherin/EMT pathway. RUNX3 may be recommended as an effective prognostic indicator and therapeutic target for patients with HCC.

Aberrant methylation of RUNX3 is present in Aflatoxin B1-induced transformation of the L02R cell line

Chronic exposure to aflatoxin B₁ (AFB₁) is linked to the development of hepatocellular carcinoma (HCC). To identify differentially methylated genes involved in AFB₁-induced cell transformation, we analyzed DNA methylation patterns in immortal human hepatocyte L02 cells expressing an oncogenic H-Ras allele (L02R cells) and AFB₁-transformed L02R (L02RT-AFB₁) cells by performing genome-wide methylation profiling. We treated L02R cells with 0.3μM AFB₁ weekly and observed a transformed phenotype at the 17th week post-treatment. The transformed cells (L02RT-AFB₁) could grow in an anchorage independent fashion and form tumors in immunodeficient mice. qRT-PCR was performed to examine whether gene methylation led to a reduction in gene expression of methylated candidate genes. As a result, the expression of the following seven genes including JUNB, RUNX3, NAV1, CXCR4, RARRES1, INTS1, and POLL was down-regulated in transformed L02RT-AFB₁ cells. The reduction of gene expression of these genes could be reversed by treatment of 5-azadeoxycytidine. The methylated CpG sites of RUNX3 genes were verified using bisulfite sequencing PCR (BSP) assay. Furthermore, a dynamic change in RUNX3 methylation was observed over the course of AFB₁-induced cell transformation, which was corresponded to the alteration of gene expression and the extent of DNA damage. In vitro study showed that methylation of RUNX3 tended to abate in L02R cells treated with AFB₁ for a short-term period of time. Notably, hypermethylation of RUNX3 appeared in 70% (14/20) of human hepatocellular carcinomas. Moreover, LINE-1 hypomethylation and dynamic changes of DNMTs, TETs and MeCP2 expression were also observed during AFB₁-induced transformation. Taken together, these observations suggest that aberrant methylation of RUNX3 and LINE-1 might be involved in AFB₁-induced carcinogenesis.

LRG1 promotes proliferation and inhibits apoptosis in colorectal cancer cells via RUNX1 activation

Leucine-rich-alpha-2-glycoprotein 1 (LRG1) has been shown to be involved in various human malignancies. Whether it plays a role in colorectal cancer (CRC) development remains unclear. Here, we investigated whether and through what mechanism LRG1 functions in human CRC cells. The plasma level of LRG1 was significantly increased in CRC patients, but it was remarkably decreased in patients with resected colorectal cancers. Meanwhile, both mRNA and protein levels of LRG1 were remarkable overexpressed in CRC tissues than normal tissues. The knockdown of LRG1 significantly inhibited cell proliferation, induced cell cycle arrest at the G0/G1 phase, and promoted apoptosis in SW480 and HCT116 cells in vitro. In addition, LRG1 silencing led to the downregulation of the levels of key cell cycle factors, such as cyclin D1, B, and E and anti-apoptotic B-cell lymphoma-2(Bcl-2). However, it up-regulated the expression of pro-apoptotic Bax and cleaved caspase-3. Furthermore, RUNX1 could be induced by LRG1 in a concentration-dependent manner, while the knockdown of RUNX1 blocked the promotion of the proliferation and inhibition of apoptosis induced by LRG1. Collectively, these findings indicate that LRG1 plays a crucial role in the proliferation and apoptosis of CRC by regulating RUNX1 expression. Thus, LRG1 may be a potential detection biomarker as well as a marker for monitoring recurrence and therapeutic target for CRC.

Loss of RUNX3 expression promotes cancer-associated bone destruction by regulating CCL5, CCL19 and CXCL11 in non-small cell lung cancer

Non‐small cell lung cancer (NSCLC) frequently metastasizes to bone, which is associated with significant morbidity and a dismal prognosis. RUNX3 functions as a tumour suppressor in lung cancer and loss of expression occurs more frequently in invasive lung adenocarcinoma than in pre‐invasive lesions. Here, we show that RUNX3 and RUNX3‐regulated chemokines are linked to NSCLC‐mediated bone resorption. Notably, the receptor activator of nuclear factor‐κB ligand (RANKL)/osteoprotegerin (OPG) ratio, an index of osteoclastogenic stimulation, was significantly increased in human osteoblastic cells treated with conditioned media derived from RUNX3‐knockdown NSCLC cells. We aimed to identify RUNX3‐regulated factors that modify the osteoblastic RANKL/OPG ratio and found that RUNX3 knockdown led to CCL5 up‐regulation and down‐regulation of CCL19 and CXCL11 in NSCLC cells. Tumour size was noticeably increased and more severe osteolytic lesions were induced in the calvaria and tibiae of mice that received RUNX3‐knockdown cells. In response to RUNX3 knockdown, serum and tissue levels of CCL5 increased, whereas CCL19 and CXCL11 decreased. Furthermore, CCL5 increased the proliferation, migration, and invasion of lung cancer cells in a dose‐dependent manner; however, CCL19 and CXCL11 did not show any significant effects. The RANKL/OPG ratio in osteoblastic cells was increased by CCL5 but reduced by CCL19 and CXCL11. CCL5 promoted osteoclast differentiation, but CCL19 and CXCL11 reduced osteoclastogenesis in RANKL‐treated bone marrow macrophages. These findings suggest that RUNX3 and related chemokines are useful markers for the prediction and/or treatment of NSCLC‐induced bone destruction. © 2015 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Clinicopathological significance and potential drug target of RUNX3 in non-small cell lung cancer: a meta-analysis

BACKGROUND

Emerging evidence indicates that RUNX3 is a candidate tumor suppressor in several types of human tumors, including non-small cell lung cancer (NSCLC). However, the correlation between RUNX3 hypermethylation and clinicopathological characteristics of NSCLC remains unclear. Here, we conducted a systematic review and meta-analysis to quantitatively evaluate the effects of RUNX3 hypermethylation on the incidence of NSCLC and clinicopathological characteristics.

METHODS

A detailed literature search was made using Medline, Embase and Web of Science for related research publications written in English. The methodological quality of the studies was evaluated. The data were extracted and assessed independently by two reviewers. Analysis of pooled data was performed. The odds ratio (OR) and hazard ratio were calculated and summarized.

RESULTS

Final analysis of 911 NSCLC patients from 13 eligible studies was performed. We observed that RUNX3 hypermethylation was significantly higher in NSCLC than in normal lung tissue; the pooled OR from seven studies including 361 NSCLC and 345 normal lung tissue (OR 7.08, confidence interval 4.12-12.17, P<0.00001). RUNX3 hypermethylation may also be associated with pathological types. The pooled OR was obtained from eleven studies including 271 squamous cell carcinoma and 389 adenocarcinoma (OR 0.41, confidence interval 0.19-0.89, P=0.02), which indicated that RUNX3 hypermethylation is significantly higher in adenocarcinoma that in squamous cell carcinoma. We did not find that RUNX3 hypermethylation was correlated with clinical stage or differentiated status. However, NSCLC patients with RUNX3 hypermethylation had a lower survival rate than those without RUNX3 hypermethylation.

CONCLUSION

The results of this meta-analysis suggest that RUNX3 hypermethylation is associated with an increased risk and worse survival in NSCLC. RUNX3 hypermethylation, which induces inactivation of the RUNX3 gene, plays an important role in lung carcinogenesis and clinical outcome.

Potentially functional SNPs (pfSNPs) as novel genomic predictors of 5-FU response in metastatic colorectal cancer patients

5-Fluorouracil (5-FU) and its pro-drug Capecitabine have been widely used in treating colorectal cancer. However, not all patients will respond to the drug, hence there is a need to develop reliable early predictive biomarkers for 5-FU response. Here, we report a novel potentially functional Single Nucleotide Polymorphism (pfSNP) approach to identify SNPs that may serve as predictive biomarkers of response to 5-FU in Chinese metastatic colorectal cancer (CRC) patients. 1547 pfSNPs and one variable number tandem repeat (VNTR) in 139 genes in 5-FU drug (both PK and PD pathway) and colorectal cancer disease pathways were examined in 2 groups of CRC patients. Shrinkage of liver metastasis measured by RECIST criteria was used as the clinical end point. Four non-responder-specific pfSNPs were found to account for 37.5% of all non-responders (P<0.0003). Five additional pfSNPs were identified from a multivariate model (AUC under ROC = 0.875) that was applied for all other pfSNPs, excluding the non-responder-specific pfSNPs. These pfSNPs, which can differentiate the other non-responders from responders, mainly reside in tumor suppressor genes or genes implicated in colorectal cancer risk. Hence, a total of 9 novel SNPs with potential functional significance may be able to distinguish non-responders from responders to 5-FU. These pfSNPs may be useful biomarkers for predicting response to 5-FU.

Clinical significance and association of RUNX3 hypermethylation frequency with colorectal cancer: a meta-analysis

Background

The RUNX family, which is composed of RUNX1, RUNX2, and RUNX3, is a sequence-specific transcription factor family and is closely involved in a variety of cellular processes including development, differentiation, participation in the regulation of p53-dependent DNA damage response and/or tumorigenesis. Emerging evidence indicates that RUNX3 is a candidate tumor suppressor in several types of human tumors including colorectal cancer (CRC). However, the correlation of RUNX3 inactivation with CRC remains unclear. In the study reported here, we conducted a systematic review and meta-analysis to quantitatively evaluate the effects of RUNX3 hypermethylation/expression on the incidence of CRC.

Methods

A detailed search of the literature was made using Medline^® and Web of Science for related research publications written in English. The methodological quality of the studies was also evaluated. The data were extracted and assessed by two reviewers independently. Analyses of the pooled data were performed. Odds ratios (ORs) and hazard ratios were calculated and summarized, respectively.

Results

A final analysis of 1,427 CRC patients from eleven eligible studies was performed. We observed that RUNX3 hypermethylation was significantly higher in CRC than in normal colorectal mucosa. The pooled OR from six studies comprising 289 CRC and 188 normal colorectal mucosa was OR =0.07 (confidence interval [CI] =0.03–0.18, P<0.00001). Aberrant RUNX3 hypermethylation/expression was significantly higher in advanced CRC than in early staged CRC (OR =0.54, CI =0.41–0.71, P<0.0001). Aberrant RUNX3 hypermethylation/expression was also significantly higher in microsatellite instability (MSI)-positive CRC than in MSI-negative CRC (OR =0.44, CI =0.3–0.66, P<0.0001). In addition, CRC patients with RUNX3 hypermethylation or lacking RUNX3 protein expression had a lower survival rate than those without RUNX3 hypermethylation or those who did not express RUNX3 protein.

Conclusion

The results of this meta-analysis suggest that RUNX3 hypermethylation is associated with an increased risk of CRC, increased risk of progression of CRC, and a poorer CRC survival rate. RUNX3 hypermethylation, which induces the inactivation of RUNX3 gene, plays an important role in colorectal carcinogenesis, high levels of MSI, as well as CRC progression and development.

Role of RUNX3 in suppressing metastasis and angiogenesis of human prostate cancer

RUNX3 (runt-related transcription factor-3) has been reported to suppress tumor tumorigenesis and metastasis in different human cancers. In this study, we used tissue microarray (TMA) to determine the significance of RUNX3 in prostate cancer progession. Our results showed ectopic expression of RUNX3 in prostate cancer tissues when compared with tumor adjacent normal prostate tissues, and reduced RUNX3 staining was significantly correlated with TNM stage. Moreover, we demonstrated that RUNX3 overexpression inhibited prostate cancer cell migration and invasion resulting from the elevated upregulation of tissue inhibitor of matrix metalloproteinase-2 (TIMP-2), which subsequently inhibited metalloproteinase-2 (MMP-2) expression and activity in vitro. Knock down of RUNX3 expression broke up the balance of TIMP-2/MMP-2, whereas silence of TIMP-2 resulted in the inhibition of MMP-2 expression in prostate cells. We also showed that restoration of RUNX3 decreased vascular endothelial growth factor (VEGF) secretion and suppressed endothelial cell growth and tube formation. Strikingly, RUNX3 was demonstrated to inhibit tumor metastasis and angiogenesis in vivo. Altogether, our results support the tumor suppressive role of RUNX3 in human prostate cancer, and provide insights into development of targeted therapy for this disease.

Clinicopathological significance and potential drug target of RUNX3 in breast cancer

BACKGROUND

Previous reports indicate that RUNX3 is a tumor suppressor in several types of human tumors, including breast cancer (BC). However, the correlation between RUNX3 hypermethylation and the incidence of BC remains unclear. In this study, we conducted a systematic review and meta-analysis aiming to comprehensively assess the potential role of RUNX3 hypermethylation in the pathogenesis of BC.

METHODS

A detailed literature search was made to identify studies for related research publications. Methodological quality of the studies was evaluated. Analysis of pooled data was performed. Odds ratio (OR) was calculated and summarized respectively.

RESULTS

Final analysis of 565 BC patients from eleven eligible studies was performed. The results showed that RUNX3 hypermethylation was significantly higher in BC than in normal breast tissue, the pooled OR from nine studies including 339 BC and 248 normal breast tissue (OR =24.12, 95% confidence interval [CI] =13.50-43.11, Z=10.75, P<0.00001). Further analysis also showed significantly increased OR of RUNX3 hypermethylation in estrogen receptor (ER)-positive than in ER-negative BC patients (OR =5.67, 95% CI =2.69-11.95, Z=4.57, P<0.00001). In addition, RUNX3 messenger RNA (mRNA) high expression was found to be correlated to better overall survival in 3,455 cases of BC patients that were followed up for 20 years (hazard ratio [HR] 0.79, P=8.8×10(-5)). Interestingly, RUNX3 mRNA overexpression was found to be correlated to better overall survival in only 668 cases of ER-negative patients (HR 0.72, P=0.01), but not in 1,767 cases of ER-positive patients (HR 0.87, P=0.13).

CONCLUSION

The results of this meta-analysis suggest that RUNX3 hypermethylation may be implicated in the pathogenesis of BC. Detection of RUNX3 mRNA may be a helpful and valuable biomarker for diagnosis of BC, especially in ER-negative BC. We also discussed the significance of RUNX3 as a potential drug target.

Runx3 inactivation is a crucial early event in the development of lung adenocarcinoma

Targeted inactivation of Runx3 in mouse lung induced mucinous and nonmucinous adenomas and markedly shortened latency of adenocarcinoma formation induced by oncogenic K-Ras. RUNX3 was frequently inactivated in K-RAS mutated human lung adenocarcinomas. A functional genetic screen of a fly mutant library and molecular analysis in cultured cell lines revealed that Runx3 forms a complex with BRD2 in a K-Ras-dependent manner in the early phase of the cell cycle; this complex induces expression of p14(ARF)/p19(Arf) and p21(WAF/CIP). When K-Ras was constitutively activated, the Runx3-BRD2 complex was stably maintained and expression of both p14(ARF) and p21(WAF/CIP) was prolonged. These results provide a missing link between oncogenic K-Ras and the p14(ARF)-p53 pathway, and may explain how cells defend against oncogenic K-Ras.

Associations between genetic variants in the TGF-β signaling pathway and breast cancer risk among Hispanic and non-Hispanic white women

The TGF-β signaling pathway has a significant role in breast cancer initiation and promotion by regulating various cellular processes. We evaluated whether genetic variation in eight genes (TGF-β1, TGF-β2, TGF-βR1, TGF-βR2, TGF-βR3, RUNX1, RUNX2, and RUNX3) is associated with breast cancer risk in women from the Breast Cancer Health Disparities Study. A total of 3,524 cases (1,431 non-Hispanic whites (NHW); 2,093 Hispanics/Native Americans(NA)) and 4,209 population-based controls (1,599 NHWs; 2,610 Hispanics/NAs) were included in analyses. Genotypes for 47 single nucleotide polymorphisms (SNPs) were determined. Additionally, 104 ancestral informative markers estimated proportion of NA ancestry. Associations with breast cancer risk overall, by menopausal status, NA ancestry, and estrogen receptor (ER)/progesterone receptor tumor phenotype were evaluated. After adjustment for multiple comparisons, two SNPs were significantly associated with breast cancer risk: RUNX3 (rs906296 ORCG/GG = 1.15 95 % CI 1.04-1.26) and TGF-β1 (rs4803455 ORCA/AA = 0.89 95 % CI 0.81-0.98). RUNX3 (rs906296) and TGF-βR2 (rs3773644) were associated with risk in pre-menopausal women (p adj = 0.002 and 0.02, respectively) and in those with intermediate to high NA ancestry (p adj = 0.04 and 0.01, respectively). Self-reported race was strongly correlated with NA ancestry (r = 0.86). There was a significant interaction between NA ancestry and RUNX1 (rs7279383, p adj = 0.04). Four RUNX SNPs were associated with increased risk of ER- tumors. Results provide evidence that genetic variation in TGF-β and RUNX genes are associated with breast cancer risk. This is the first report of significant associations between genetic variants in TGF-β and RUNX genes and breast cancer risk among women of NA ancestry.

RUNX3 suppresses migration, invasion and angiogenesis of human renal cell carcinoma

RUNX3 (runt-related transcription factor-3) is a known tumor suppressor gene which exhibits potent antitumor activity in several carcinomas. However, little is known about the role of RUNX3 in human renal cell carcinoma (RCC). To investigate the clinical relevance of RUNX3 in RCC patients, immunohistochemistry was performed to detect the clinical relevance of RUNX3 in 75 RCC tissues and paired non-cancerous tissues by using tissue microarray (TMA). We also investigated the role of RUNX3 in RCC cell migration, invasion and angiogenesis. The RUNX3 expression was decreased dramatically in human RCC tissue. The RUNX3 expression was significantly correlated with tumor size (P<0.001), depth of invasion (P<0.001), and of TNM stage (P<0.001). Restoration of RUNX3 significantly decreased renal carcinoma cell migration and invasion capacity compared with controls. In addition, we found that overexpression of RUNX3 reduced the proliferation and tube formation of human umbilical vascular endothelial cells (HUVECs). Gelatin zymography and Western blot showed that RUNX3 expression suppressed matrix metalloproteinase-9 (MMP-9) protein level and enzyme activity. Western blot and ELISA showed that RUNX3 restoration inhibited the expression and secretion of vascular endothelial growth factor (VEGF). Taken together, our studies indicate that decreased expression of RUNX3 in human RCC tissue is significantly correlated with RCC progression. Restoration of RUNX3 expression significantly inhibits RCC cells migration, invasion and angiogenesis. These findings provide new insights into the significance of RUNX3 in migration, invasion and angiogenesis of RCC.

The Current and Future Therapies for Human Osteosarcoma

Osteosarcoma (OS) is the most common non-hematologic malignant tumor of bone in adults and children. As sarcomas are more common in adolescents and young adults than most other forms of cancer, there are a significant number of years of life lost secondary to these malignancies. OS is associated with a poor prognosis secondary to a high grade at presentation, resistance to chemotherapy and a propensity to metastasize to the lungs. Current OS management involves both chemotherapy and surgery. The incorporation of cytotoxic chemotherapy into therapeutic regimens escalated cure rates from <20% to current levels of 65-75%. Furthermore, limb-salvage surgery is now offered to the majority of OS patients. Despite advances in chemotherapy and surgical techniques over the past three decades, there has been stagnation in patient survival outcome improvement, especially in patients with metastatic OS. Thus, there is a critical need to identify novel and directed therapy for OS. Several Phase I trials for sarcoma therapies currently ongoing or recently completed have shown objective responses in OS. Novel drug delivery mechanisms are currently under phase II and III clinical trials. Furthermore, there is an abundance of preclinical research which holds great promise in the development of future OS-directed therapeutics. Our continuously improving knowledge of the molecular and cell-signaling pathways involved in OS will translate into more effective therapies for OS and ultimately improved patient survival. The present review will provide an overview of current therapies, ongoing clinical trials and therapeutic targets under investigation for OS.

Groucho: a corepressor with instructive roles in development

Drosophila Groucho (Gro) is the founding member of a family of metazoan corepressors. Gro mediates repression through interactions with a myriad of DNA-binding repressor proteins to direct the silencing of genes involved in many developmental processes, including neurogenesis and patterning of the main body axis, as well as receptor tyrosine kinase/Ras/MAPK, Notch, Wingless (Wg)/Wnt, and Decapentaplegic (Dpp) signaling. Gro mediates repression by multiple molecular mechanisms, depending on the regulatory context. Because Gro is a broadly expressed nuclear factor, whereas its repressor partners display restricted temporal and spatial distribution, it was presumed that this corepressor played permissive rather than instructive roles in development. However, a wide range of studies demonstrates that this is not the case. Gro can sense and integrate many cellular inputs to modulate the expression of variety of genes, making it a versatile corepressor with crucial instructive roles in development and signaling.

RUNX1 and its understudied role in breast cancer

The transcription factor Runt-related transcription factor 1 (RUNX1) is critical for the earliest steps of hematopoiesis. RUNX1 was originally identified as a gene fusion in acute myeloid leukemia (AML) and thus has garnered heavy attention as a tumor suppressor in hematopoietic malignancies. However, RUNX1 is also strongly expressed in breast epithelia and may be misregulated during tumorigenesis. Here, I discuss our recent work implicating RUNX1 in proliferation control during breast epithelial-acinar morphogenesis. My goal is to place these findings in the context of a handful of other reports, which together argue that RUNX1 could act as a tumor suppressor gene in breast cancer. Testing this hypothesis requires focused in vivo studies, because the major commercial platform for global mRNA expression profiling does not reliably reflect RUNX1 levels. Our in vitro results indicate that hyperproliferation in RUNX1-deficient breast epithelia relies on another family of transcription factors, the Forkhead box O (FOXO) proteins. FOXOs could, therefore, represent a synthetic-lethal target for RUNX1-deficient tumors if the hypothesized link to breast cancer is correct.

RUNX transcription factors: association with pediatric asthma and modulated by maternal smoking

Intrauterine smoke exposure (IUS) is a strong risk factor for development of airways responsiveness and asthma in childhood. Runt-related transcription factors (RUNX1-3) have critical roles in immune system development and function. We hypothesized that genetic variations in RUNX1 would be associated with airway responsiveness in asthmatic children and that this association would be modified by IUS. Family-based association testing analysis in the Childhood Asthma Management Program genome-wide genotype data showed that 17 of 100 RUNX1 single-nucleotide polymorphisms (SNPs) were significantly (P < 0.03-0.04) associated with methacholine responsiveness. The association between methacholine responsiveness and one of the SNPs was significantly modified by a history of IUS exposure. Quantitative PCR analysis of immature human lung tissue with and without IUS suggested that IUS increased RUNX1 expression at the pseudoglandular stage of lung development. We examined these associations by subjecting murine neonatal lung tissue with and without IUS to quantitative PCR (N = 4-14 per group). Our murine model showed that IUS decreased RUNX expression at postnatal days (P)3 and P5 (P < 0.05). We conclude that 1) SNPs in RUNX1 are associated with airway responsiveness in asthmatic children and these associations are modified by IUS exposure, 2) IUS tended to increase the expression of RUNX1 in early human development, and 3) a murine IUS model showed that the effects of developmental cigarette smoke exposure persisted for at least 2 wk after birth. We speculate that IUS exposure-altered expression of RUNX transcription factors increases the risk of asthma in children with IUS exposure.

Runx3 suppresses gastric cancer metastasis through inactivation of MMP9 by upregulation of TIMP-1

Recent studies have suggested that loss of RUNX3 expression is involved with gastric tumor metastasis. However, the precise mechanism of RUNX3-mediated suppression of tumor metastasis remains elusive. We aimed to clarify the effect of RUNX3 on tumor metastasis in gastric cancer cell lines and tumors. Immunohistochemistry revealed that RUNX3 was significantly decreased in metastatic gastric cancer. Gelatin zymography and Western blot showed that instead of regulating matrix metalloproteinase 9 (MMP9) expression, RUNX3 expression inhibited MMP9 enzyme activity, and this was consistent with the upregulation of tissue inhibitor of metalloproteinases 1 (TIMP1) by RUNX3. TIMP1 siRNA treatment impaired RUNX3-mediated suppression of gastric cancer cell invasion. Reporter assays demonstrated regulation of TIMP-1 by RUNX3. Two RUNX3 binding sites were identified in the TIMP-1 promoter and direct interaction of RUNX3 with the TIMP-1 promoter was confirmed in vitro and in vivo. These findings provide evidence for RUNX3-mediated suppression of gastric cancer invasion and metastasis and define a novel molecular mechanism that for the metastasis-inhibiting activity of RUNX3. These data may be applied in the development of RUNX3 for gastric cancer metastasis diagnostics and therapeutics.

Expression of RUNX3 in skin cancers

BACKGROUND

Expression of Runt-related transcription factor 3 (RUNX3) is reduced in a large number of cancers. However, a few studies have reported higher expression of RUNX3 in several cancers, including basal cell carcinoma (BCC). In light of this, we explored the expression of RUNX3 in skin cancers generally, to determine whether it acts as an oncogene or a tumour-suppressor gene in skin tumours.

AIM

To investigate the expression of RUNX3 in normal skin and malignant skin tumours.

METHODS

RUNX3 expression was evaluated by western blotting in 24 specimens, comprising 6 malignant melanoma (MM), 6 squamous cell carcinoma (SCC), 6 BCC and 6 normal skin specimens. Immunohistochemical staining was carried out to analyse RUNX3 expression in 16 MM, 16 SCC and 16 BCC specimens. To identify where the protein was expressed, the cytoplasmic and nuclear protein expression of RUNX3 in skin cancer tissues was determined. A cell-proliferation study was performed on an MM line (G361) by small interfering (si)RNA transfection.

RESULTS

The western blotting experiments showed that RUNX3 was not expressed in normal skin tissues, but it was overexpressed in all MM and SCC samples, and in five of the six BCC samples. Using immunochemistry, RUNX3 was found to be overexpressed in all cancer tissues analysed. Subcellular fraction analysis revealed that RUNX3 was expressed in the nuclei but not the cytoplasm of all the skin cancer tissues analysed, and RUNX3 silencing by siRNA in G361 cells resulted in a decrease in proliferation.

CONCLUSIONS

Based on these results, we suggest that RUNX3 has an oncogenic potential and does not act as a tumour suppressor in skin cancers.

Nicotinamide inhibits growth of carcinogen induced mouse bladder tumor and human bladder tumor xenograft through up-regulation of RUNX3 and p300

PURPOSE

Acetylation of chromatin interacting proteins is central to the epigenetic regulation of gene expression. Various tumor suppressors are inactivated by abnormal epigenetic modification. A great deal of effort has been devoted to developing anticancer agents that reactivate silenced tumor suppressors by modulating chromatin structure. Studies show that histone deacetylase inhibitors can act as anticancer agents and several histone deacetylase inhibitors are currently in clinical trials. We noted that the tumor suppressor RUNX3 is inactivated by promoter hypermethylation in human bladder cancer. We investigated whether reactivation of RUNX3 could suppress bladder cancer development in an animal model.

MATERIALS AND METHODS

We analyzed RUNX3 reactivation and protein stabilization by a mild inhibitor of class III histone deacetylases, nicotinamide, by immunoprecipitation and immunoblot. Mouse bladder tumor was induced by N-butyl-N-(4-hydroxybutyl) nitrosamine. The effect of nicotinamide on Runx3 methylation status and tumor growth was measured.

RESULTS

Nicotinamide induced RUNX3 expression at the transcriptional and posttranslational levels in a carcinogen induced mouse bladder tumor model and in human bladder tumor xenografts. Nicotinamide effectively inhibited the growth and progression of bladder tumors without decreasing body weight.

CONCLUSIONS

Results suggest that nicotinamide has preventive and therapeutic effects on tumorigenesis through multiple mechanisms of RUNX3 expression up-regulation.

Defective osteogenic differentiation in the development of osteosarcoma

Osteosarcoma (OS) is associated with poor prognosis due to its high incidence of metastasis and chemoresistance. It often arises in areas of rapid bone growth in long bones during the adolescent growth spurt. Although certain genetic conditions and alterations increase the risk of developing OS, the molecular pathogenesis is poorly understood. Recently, defects in differentiation have been linked to cancers, as they are associated with high cell proliferation. Treatments overcoming these defects enable terminal differentiation and subsequent tumor inhibition. OS development may be associated with defects in osteogenic differentiation. While early regulators of osteogenesis are unable to bypass these defects, late osteogenic regulators, including Runx2 and Osterix, are able to overcome some of the defects and inhibit tumor propagation through promoting osteogenic differentiation. Further understanding of the relationship between defects in osteogenic differentiation and tumor development holds tremendous potential in treating OS.

Prognostic significance of RUNX3 expression in human melanoma

BACKGROUND

RUNX3 is a tumor suppressor that plays important roles in cell proliferation, apoptosis, and metastasis. The authors investigated the role of RUNX3 in melanoma pathogenesis and analyzed the prognostic impact of RUNX3 expression in a large series of melanoma patients.

METHODS

Two sets of tissue microarrays were constructed, including 440 cases of melanomas (202 for the training set and 238 for the validation set) and 88 cases of nevi (25 normal nevi and 63 dysplastic nevi). RUNX3 expression was evaluated by immunohistochemistry.

RESULTS

Positive RUNX3 expression was observed in 56%, 54%, 33%, and 24% of the biopsies in normal nevi, dysplastic nevi, primary melanoma, and melanoma metastases, respectively. Significant differences for positive nuclear RUNX3 staining were observed between dysplastic nevi and primary melanomas (P = .002, chi-square test), between dysplastic nevi and melanoma metastases (P < .001, chi-square test), and between primary melanoma and melanoma metastases (P = .045, chi-square test). Loss of RUNX3 expression was correlated with a worse 5-year survival of melanoma patients in both training and validation sets. Furthermore, loss of RUNX3 expression was also correlated with a poor 5-year disease-specific survival in primary melanoma (P = .001) and metastatic melanoma patients (P = .008). Multivariate Cox regression analysis revealed that positive RUNX3 expression is an independent prognostic factor to predict melanoma patient outcome.

CONCLUSIONS

Our findings indicate that RUNX3 plays an important role in melanoma pathogenesis and may serve as a promising prognostic marker for melanoma.

Associations between genetic variation in RUNX1, RUNX2, RUNX3, MAPK1 and eIF4E and riskof colon and rectal cancer: additional support for a TGF-β-signaling pathway

The Runt-related transcription factors (RUNX), mitogen-activated protein kinase (MAPK) 1 and eukaryotic translation initiation factor 4E (eIF4E) are potentially involved in tumorigenesis. We evaluated genetic variation in RUNX1 (40 tagSNPs), RUNX2 (19 tagSNPs), RUNX3 (9 tagSNPs), MAPK1 (6 tagSNPs), eIF4E (3 tagSNPs), eIF4EBP2 (2 tagSNP) and eIF4EBP3 (2 tagSNPs) to determine associations with colorectal cancer (CRC). We used data from population-based studies (colon cancer n = 1555 cases, 1956 controls; rectal cancer n = 754 cases, 959 controls with complete genotype data). Four statistically significant tagSNPs were identified with colon cancer and three tagSNPs were identified with rectal cancer. Whereas the independent risk estimates for each of the tagSNPs ranged from 1.21 to 1.52, the combined risk was greater than additive for any of the three combined high-risk genotypes {combined risk range 1.98 [95% confidence interval (CI) 1.45, 2.70] for eIF4E, RUNX1 and RUNX3 to 3.32 [95% CI 1.34, 8.23] for eIF43, RUNX2 and RUNX3}. For rectal cancer, the strongest association was detected for the combined genotype of RUNX1 and RUNX3 (odds ratio 1.87 95% CI 1.22, 2.87). Associations with specific molecular tumor phenotypes showed consistent and strong associations for CIMP+/MSI+ tumors where the risk estimates were consistently >10-fold and lower confidence bounds were over 3.00 for high-risk genotypes defined by RUNX1, RUNX2 and RUNX3. For CIMP+/KRAS2-mutated colon tumors, the combined risk for high-risk genotypes of RUNX2, eIF4E and RUNX1 was 7.47 (95% CI 1.58, 35.3). Although the associations need confirmation, the findings and their internal consistency underline the importance of genetic variation in these genes for the etiology of CRC.

Runx regulation of sphingolipid metabolism and survival signaling

The Runx genes (Runx1, 2, and 3) regulate cell fate in development and can operate as either oncogenes or tumor suppressors in cancer. The oncogenic potential of ectopic Runx expression has been shown in transgenic mice that develop lymphoma in potent synergy with overexpressed Myc, and in established fibroblasts that display altered morphology and increased tumorigenicity. Candidate oncogenic functions of overexpressed Runx genes include resistance to apoptosis in response to intrinsic and extrinsic stresses. In a search for gene targets responsible for this aspect of Runx phenotype, we have identified three key enzymes in sphingolipid metabolism (Sgpp1, Ugcg, and St3gal5/Siat9) as direct targets for Runx transcriptional regulation in a manner consistent with survival and apoptosis resistance. Consistent with these changes in gene expression, mass spectrometric analysis showed that ectopic Runx reduces intracellular long-chain ceramides in NIH3T3 fibroblasts and elevated extracellular sphingosine 1 phosphate. Runx expression also opposed the activation of c-Jun-NH(2)-kinase and p38(MAPK), key mediators of ceramide-induced death, and suppressed the onset of apoptosis in response to exogenous tumor necrosis factor alpha. The survival advantage conferred by ectopic Runx could be partially recapitulated by exogenous sphingosine 1 phosphate and was accompanied by reduced phosphorylation of p38(MAPK). These results reveal a novel link between transcription factor oncogenes and lipid signaling pathways involved in cancer cell survival and chemoresistance.

Risk factors in malignant transformation of gastric epithelial neoplasia categorized by the revised Vienna classification: endoscopic, pathological, and immunophenotypic features

BACKGROUND

According to the revised Vienna classification, the surgical removal of gastric epithelial neoplasia category 3 (low-grade dysplasia) lesions is not necessary, whereas the removal of category 4 lesions (high-grade dysplasia and intramucosal cancer) is obligatory. However, approximately 15%-30% of low-grade adenomas/dysplasia progress to high-grade lesions or adenocarcinoma, and it is difficult to determine which lesions will advance to true malignancy. The aim of this study was to evaluate the endoscopic, pathological, and immunophenotypic differences between category 3 and 4 lesions according to the revised Vienna classification.

METHODS

All tissue samples were excised by endoscopic mucosal resection. Fifty-two category 3 tissue samples and 54 category 4 samples were evaluated by endoscopic findings; by pathology examination of the surrounding mucosa; and by CD10, MUC2, MUC5AC, MUC6, and RUNX3 immunohistochemical staining.

RESULTS

Univariate analysis showed that the size of the lesion, color change, ulceration, gastritis score of the surrounding mucosa, and positive expression of MUC6 were associated with category 4 lesions. Multivariate analysis showed that the size of the lesion, ulceration, and positive expression of MUC6 were strongly associated with category 4 lesions.

CONCLUSION

Lesions more than 17 mm in diameter or lesions that are associated with ulceration have the potential for malignant transformation. Positive immunoreactivity for MUC6 appears to be a complementary marker for malignant transformation of gastric epithelial neoplasia.

Runx3 is required for the differentiation of lung epithelial cells and suppression of lung cancer

Human lung adenocarcinoma, the most prevalent form of lung cancer, is characterized by many molecular abnormalities. K-ras mutations are associated with the initiation of lung adenocarcinomas, but K-ras-independent mechanisms may also initiate lung tumors. Here, we find that the runt-related transcription factor Runx3 is essential for normal murine lung development and is a tumor suppressor that prevents lung adenocarcinoma. Runx3-/- mice, which die soon after birth, exhibit alveolar hyperplasia. Importantly, Runx3-/- bronchioli exhibit impaired differentiation, as evidenced by the accumulation of epithelial cells containing specific markers for both alveolar (that is SP-B) and bronchiolar (that is CC10) lineages. Runx3-/- epithelial cells also express Bmi1, which supports self-renewal of stem cells. Lung adenomas spontaneously develop in aging Runx3+/- mice ( approximately 18 months after birth) and invariably exhibit reduced levels of Runx3. As K-ras mutations are very rare in these adenomas, Runx3+/- mice provide an animal model for lung tumorigenesis that recapitulates the preneoplastic stage of human lung adenocarcinoma development, which is independent of K-Ras mutation. We conclude that Runx3 is essential for lung epithelial cell differentiation, and that downregulation of Runx3 is causally linked to the preneoplastic stage of lung adenocarcinoma.

Significant association of RUNX3 T/A polymorphism at intron 3 (rs760805) with the risk of gastric atrophy in Helicobacter pylori seropositive Japanese

BACKGROUND

This study aimed to examine the associations of a RUNX3 T/A polymorphism at exon 1 (Asn18Ile) (rs6672420) and another RUNX3 intronic T/A polymorphism (rs760805) with the risk of gastric cancer together with the risk of H. pylori seropositivity and gastric atrophy in Japanese people.

METHODS

Study subjects were 583 histologically diagnosed gastric cancer patients and age- and sex-frequency-matched 1,742 control outpatients (among whom 1,637 subjects were eligible for the analyses), who visited Aichi Cancer Center Hospital from 2001 to 2005. Serum pepsinogens were measured to evaluate gastric atrophy.

RESULTS

There was no significant association between the RUNX3 polymorphisms and the seropositivity. Among H. pylori seropositive subjects, we found a significant association between RUNX3 rs760805 polymorphism and the risk of gastric atrophy with the age- and sex-adjusted OR of 1.51 (95% CI 1.11-2.05, P = 0.008) in T/A, 1.59 (95% CI 1.08-2.33, P = 0.019) in A/A, and 1.53 (95% CI 1.14-2.05, P = 0.004) in T/A + A/A, compared with T/T genotype. We found no statistically significant associations between RUNX3 rs6672420 polymorphism and risk of gastric atrophy, nor between these two RUNX3 polymorphisms and the risk of gastric cancer relative to the subjects with gastric atrophy.

CONCLUSIONS

Our study results revealed that the RUNX3 intronic T/A polymorphism (rs760805) might modulate the risk of gastric atrophy among H. pylori seropositive subjects, and the RUNX3 T/A polymorphism at exon 1 (rs6672420) had little influence on the risks of H. pylori infection, gastric atrophy or gastric cancer in Japanese people. Further investigation is required to verify our findings.