Loss of runt-related transcription factor 3 causes development and progression of hepatocellular carcinoma

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.

Integrated Bioinformatic Analysis Identifies TIPIN as a Prognostic Biomarker in Hepatocellular Carcinoma

Background

Gene expression and DNA methylation analyses have long been used to identify cancer markers. However, a combination analysis of the gene expression and DNA methylation has yet to be performed to identify potential biomarkers of hepatocellular carcinoma (HCC).

Methods

By matching gene expression profiles and promoter methylation data in The Cancer Genome Atlas (TCGA), genes with discrepant expression as well as genes with differential promoter methylation were identified. High-expression genes with low promoter methylation were defined as epigenetically induced (EI), while low-expression genes with high promoter methylation were defined as epigenetically suppressed (ES). The human protein interaction network was further integrated to construct the EI/ES gene interaction network, and the key genes in the subnet were identified as potential HCC biomarkers. The expression differences and prognostic values were verified in TCGA and Gene Expression Omnibus (GEO) databases, as well as with tissue chip technology.

Results

Four key genes were identified: TIPIN, RBM15B, DUSP28, and TRIM31, which demonstrated the differential gene expression and prognostic value in TCGA and GEO databases. Tissue microarray analysis (TMA) revealed that TIPIN levels were altered in HCC. The upregulated TIPIN expression was associated with worse overall survival. Univariate and multivariate analyses showed that the TIPIN expression was an independent predictor of HCC.

Conclusion

TIPIN might be a potential novel prognostic biomarker for HCC.

Effect of circular RNA, mmu_circ_0000296, on neuronal apoptosis in chronic cerebral ischaemia via the miR-194-5p/Runx3/Sirt1 axis

Chronic cerebral ischaemia (CCI) is a common pathological disorder, which is associated with various diseases, such as cerebral arteriosclerosis and vascular dementia, resulting in neurological dysfunction. As a type of non-coding RNA, circular RNA is involved in regulating the occurrence and development of diseases, such as ischaemic brain injury. Here, we found that HT22 cells and hippocampus treated with CCI had low expression of circ_0000296, Runx3, Sirt1, but high expression of miR-194-5p. Overexpression of circ_0000296, Runx3, Sirt1, and silenced miR-194-5p significantly inhibited neuronal apoptosis induced by CCI. This study demonstrated that circ_0000296 specifically bound to miR-194-5p; miR-194-5p bound to the 3'UTR region of Runx3 mRNA; Runx3 directly bound to the promoter region of Sirt1, enhancing its transcriptional activity. Overexpression of circ_0000296 by miR-194-5p reduced the negative regulatory effect of miR-194-5p on Runx3, promoted the transcriptional effect of Runx3 on Sirt1, and inhibited neuronal apoptosis induced by CCI. mmu_circ_0000296 plays an important role in regulating neuronal apoptosis induced by CCI through miR-194-5p/Runx3/Sirt1 pathway.

Long non-coding RNA LINC01215 promotes epithelial-mesenchymal transition and lymph node metastasis in epithelial ovarian cancer through RUNX3 promoter methylation

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The study first reports the regulation of LINC01215 on methylation of RUNX3 promoter.

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LINC01215 is highly expressed while RUNX3 is reciprocal in EOC.

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LINC01215 overexpression promotes methylation of RUNX3 and reduces its expression.

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LINC01215 silencing suppresses LNM and EMT of EOC.

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This study may provide a new therapeutic target for EOC.

Epithelial ovarian cancer (EOC) still remains the most lethal gynaecological malignancy in women, despite the recent progress in the management, including surgery and chemotherapy. According to the microarray data of the GSE18520 and GSE54388 datasets, LINC01215 was identified as an upregulated long noncoding RNA (lncRNA) in EOC. Therefore, this study aimed to figure out the involvement of LINC01215 in the progression of EOC. RT-qPCR was conducted to select the EOC cell line with the highest expression of LINC01215. Methylation of RUNX3 was then examined in EOC cells by MS-PCR. Furthermore, the interaction between LINC01215 and methylation-related proteins was revealed according to the results of RIP and RNA pull down assays. Subsequently, the involvement of LINC01215 and RUNX3 in regulating biological behaviors of EOC cells was investigated. Finally, the effects of the ectopic expression of LINC01215 and RUNX3 on the tumor formation and lymph node metastasis (LNM) of EOC cells were assessed in the xenograft tumors of nude mice. Overexpressing LINC01215 contributed to downregulated levels of RUNX3, as demonstrated by the recruitment of methylation-related proteins. Silencing of LINC01215 elevated the expression of RUNX3, thus suppressing cell proliferation, migration, invasion and EMT and decreasing the expressions of MMP-2, MMP-9 and Vimentin, but increased the expression of E-cadherin. The tumor growth and LNM were suppressed by downregulated levels of LINC01215 through inducing the expression of RUNX3. Collectively, the down-regulating LINC01215 could upregulate the expression of RUNX3 by promoting its methylation, thus suppressing EOC cell proliferation, migration and invasion, EMT, tumor growth and LNM.

PIWI-interacting RNAs and PIWI proteins in glioma: molecular pathogenesis and role as biomarkers

Glioma is the most common primary brain tumor, and is a major health problem throughout the world. Today, researchers have discovered many risk factors that are associated with the initiation and progression of gliomas. Studies have shown that PIWI-interacting RNAs (piRNAs) and PIWI proteins are involved in tumorigenesis by epigenetic mechanisms. Hence, it seems that piRNAs and PIWI proteins may be potential prognostic, diagnostic or therapeutic biomarkers in the treatment of glioma. Previous studies have demonstrated a relationship between piRNAs and PIWI proteins and some of the molecular and cellular pathways in glioma. Here, we summarize recent evidence and evaluate the molecular mechanisms by which piRNAs and PIWI proteins are involved in glioma.

Elevated expression of RUNX3 co-expressing with EZH2 in esophageal cancer patients from India

Background

Runt related transcription factor3 (RUNX3) is considered as a tumor suppressor gene (TSG) that functions through the TGF-β dependent apoptosis. Promoter methylation of the CpG islands of RUNX3 and overexpression of enhancer of zeste homolog 2 (EZH2) has been suggested to downregulate RUNX3 in cancer.

Methods

Here, we studied the expression of RUNX3 and EZH2 in 58 esophageal tumors along with paired adjacent normal tissue. mRNA levels, protein expressions and cellular localizations of EZH2 and RUNX3 were analyzed using real-time PCR and immunohistochemistry, respectively. DNA methylation was further assessed by the methylation specific-PCR.

Results

Compared to normal tissue, a significant increase in expression of RUNX3 mRNA in 31/57 patient’s tumor tissue (p < 0.04) was observed. The expression of EZH2 was found to be upregulated compared to normal, and a significant positive correlation between EZH2 and RUNX3 expression was observed (p = 0.002). 22 of the 27 unmethylated cases at the promoter region of the RUNX3 had elevated RUNX3 protein expression (p < 0.001).

Conclusion

The data presented in this study provide new insights into the biology of RUNX3 and highlights the need to revisit our current understanding of the role of RUNX3 in cancer.

MiR-17-5p promotes cellular proliferation and invasiveness by targeting RUNX3 in gastric cancer

BACKGROUND

Dysregulated microRNAs (miRNAs/miRs) directly modulate the biological functions of gastric cancer (GC) cells and contribute to the initiation and progression of GC. MiR-17-5p and runt-related transcription factor 3 (RUNX3) have been reported to be related to GC progression; however, the specific interaction between miR-17-5p and RUNX3 in GC require further investigation.

METHODS

Western blotting, real-time PCR and immunohistochemistry were used to study the expression level of miR-17-5p and RUNX3 in gastric cancer tissues and plasma. The biological function of miR-17-5p was examined by measuring cell proliferation, apoptosis and cell invasion in vitro; the target gene of miR17-5p was identified by luciferase reporter assays, RNA Binding protein immunoprecipitation (RIP) and western blotting. In vivo animal study was conducted to confirm the role of miR-17-5p during tumorigensis of gastric cancer.

RESULTS

This study showed that miR17-5p was upregulated in the plasma and tissues of patients with GC, while RUNX3 was downregulated in GC tissues. Functional experiments indicated that miR-17-5p mimics promoted the proliferation and invasion of GC via suppressing apoptosis in vitro. Furthermore, bioinformatics prediction, luciferase reporter assays, reverse transcription quantitative polymerase chain reaction assays, RIP and western blotting analysis demonstrated that RUNX3 was a direct target gene of miR-17-5p in GC. In addition, overexpression of RUNX3 suppressed the proliferation and invasiveness of GC cells. In vivo data indicated miR-17-5p agomir significantly promoted tumor growth. In contrast, miR-17-5p antagomir notably decreased tumor volume compared with control group.

CONCLUSIONS

MiR-17-5p promoted the progression of GC via directly targeting RUNX3, suggesting that miR-17-5p and RUNX3 could be considered as diagnostic and therapeutic targets for patients with GC.

RUNX3 inhibits the invasion and migration of esophageal squamous cell carcinoma by reversing the epithelial‑mesenchymal transition through TGF‑β/Smad signaling

Runt‑related transcription factor 3 (RUNX3) is a candidate tumor suppressor, and its inactivation may play a crucial role in the carcinogenesis process of numerous cancer types, including esophageal squamous cell carcinoma (ESCC). We previously revealed that RUNX3 inactivation was correlated with lymph node metastasis (LNM) and ESCC recurrence. However, the exact mechanisms of this process are still under investigation. The aim of the present study was to examine the potential roles and underlying molecular mechanisms of RUNX3 in ESCC metastasis and the epithelial‑mesenchymal transition (EMT). According to the results, RUNX3 expression in ESCC tissue was significantly reduced compared with that in adjacent normal tissue (0.50±0.20 vs. 0.83±0.16; P<0.001). In addition, statistical analysis revealed a close association between decreased RUNX3 expression and T status (P=0.027) and LNM (P=0.017) in ESCC patients. Pearson's correlation coefficient analysis was then used to evaluate correlations between RUNX3 and EMT‑related marker expression. The results revealed that RUNX3 expression in ESCC tissues was negatively correlated with the expression of N‑cadherin (r=‑0.429; P<0.01) and Snail (r=‑0.364; P<0.01) and positively correlated with the expression of E‑cadherin (r=0.580; P<0.01). Moreover, Eca109 and EC9706 cell invasion, migration, MMP‑9 expression and EMT were significantly inhibited by RUNX3 overexpression. Notably, further analysis revealed that RUNX3 overexpression markedly inhibited the phosphorylation of Smad2/3; RUNX3‑overexpressing cells also displayed less sensitivity to TGF‑β1‑induced EMT than control cells. Thus, RUNX3 may inhibit the invasion and migration of ESCC cells by reversing EMT through TGF‑β/Smad signaling and may be useful as a therapeutic target.

Complex Interplay between the RUNX Transcription Factors and Wnt/β-Catenin Pathway in Cancer: A Tango in the Night

Cells are designed to be sensitive to a myriad of external cues so they can fulfil their individual destiny as part of the greater whole. A number of well-characterised signalling pathways dictate the cell's response to the external environment and incoming messages. In healthy, well-ordered homeostatic systems these signals are tightly controlled and kept in balance. However, given their powerful control over cell fate, these pathways, and the transcriptional machinery they orchestrate, are frequently hijacked during the development of neoplastic disease. A prime example is the Wnt signalling pathway that can be modulated by a variety of ligands and inhibitors, ultimately exerting its effects through the β-catenin transcription factor and its downstream target genes. Here we focus on the interplay between the three-member family of RUNX transcription factors with the Wnt pathway and how together they can influence cell behaviour and contribute to cancer development. In a recurring theme with other signalling systems, the RUNX genes and the Wnt pathway appear to operate within a series of feedback loops. RUNX genes are capable of directly and indirectly regulating different elements of the Wnt pathway to either strengthen or inhibit the signal. Equally, β-catenin and its transcriptional co-factors can control RUNX gene expression and together they can collaborate to regulate a large number of third party co-target genes.

The different expression of tumor suppressors, RASSF1A, RUNX3, and GSTP1, in patients with alcoholic steatohepatitis (ASH) vs non-alcoholic steatohepatitis (NASH)

As the fifth most common cancer and the second leading cause of cancer related deaths worldwide, hepatocellular carcinoma (HCC) causes up to one million deaths annually. Alcoholic steatohepatitis (ASH) and non-alcoholic steatohepatitis (NASH) are becoming the two major risk factors because both may develop liver fibrosis and hepatocellular carcinoma (HCC) if left untreated. However, compared with 3-10% of patients with ASH may progress to HCC annually, about only 0.5% NASH patients may progress to HCC annually. The present study is to clarify the protein expression differences of tumor suppressor genes (TSGs) between ASH and NASH. In liver biopsied specimens from NASH and ASH patients, using an immunofluorescence method and morphometrically quantitating the fluorescence intensity, we studied the protein expression within hepatocytes cytoplasm of candidate TSGs including RUNX3, GSTP1, and RASSF1A. Compared with the control group of patients, the expression levels of all three proteins were upregulated in the ASH group of patients (p < .001 in all molecules). While RUNX3 was upregulated, GSTP1 and RASSF1 did not change in the NASH group of patients. The most important finding is that compared with the ASH group of patients, the expression levels of all three TSG proteins, RUNX3, GSTP1, and RASSF1, were significantly lower in the NASH group of patients (p < .001 in all three molecules). These results confirmed our previous finding that there are significant differences of many molecules including TSGs that changed in NASH compared to ASH. Thus, we conclude that there are significantly different TSGs and pathways involved during the pathogenesis of HCC development in NASH compared to ASH that may help to develop different strategies for prevention and treatment of NASH and ASH patients.

PIWIL1/piRNA-DQ593109 Regulates the Permeability of the Blood-Tumor Barrier via the MEG3/miR-330-5p/RUNX3 Axis

The blood-tumor barrier (BTB) restricts the efficient delivery of anti-glioma drugs to cranial glioma tissues. Increased BTB permeability may allow greater delivery of the therapeutic agents. Increasing evidence has revealed that PIWI proteins and PIWI-interacting RNAs (piRNAs) play an important role in tumor progression. However, whether PIWI proteins and piRNAs regulate BTB permeability remains unclear. In the present study, we demonstrated that the PIWIL1/piRNA-DQ593109 (piR-DQ593109) complex was the predominant regulator of BTB permeability. Briefly, PIWIL1 was upregulated in glioma endothelial cells (GECs). Furthermore, piR-DQ593109 was also overexpressed in GECs, as revealed via a piRNA microarray. Downregulation of PIWIL1 or piR-DQ593109 increased the permeability of the BTB. Moreover, PIWIL1 and piR-DQ593109, which formed a piRNA-induced silencing complex, degraded the long non-coding RNA maternally expressed 3 (MEG3) in a sequenced-dependent manner. Furthermore, restoring MEG3 released post-transcriptional inhibition of Runt related transcription factor 3 (RUNX3) by sponging miR-330-5p. In addition, RUNX3 bounded to the promoter regions and reduced the promoter activities of ZO-1, occludin, and claudin-5, which significantly impaired the expression levels of ZO-1, occludin, and claudin-5. In conclusion, downregulating PIWIL1 and piR-DQ593109 increased BTB permeability through the MEG3/miR-330-5p/RUNX3 axis. These data may provide insight into glioma treatment.

The clinicopathological significance of RUNX3 hypermethylation and mRNA expression in human breast cancer, a meta-analysis

Aberrant promoter methylation of RUNX3 has been reported in several tumors including human breast cancer (BC). However, the association between RUNX3 hypermethylation and incidence of BC remains elusive. In this study, a detailed literature search was performed in Medline and Google Scholar for related research publications. Analysis of pooled data were executed. Odds ratios with corresponding confidence intervals were determined and summarized, respectively. Finally, 13 studies were identified for the meta-analysis. Analysis of the pooled data showed that RUNX3 hypermethylation was significantly higher in both ductal carcinoma in situ and invasive ductal carcinoma (IDC) than in normal breast tissues. In addition, RUNX3 methylation was significantly higher in IDC than in benign tumor. However, RUNX3 methylation was not significantly higher in IDC than in ductal carcinoma in situ. We also determined that RUNX3 hypermethylation was significantly higher in ER positive BC than in ER negative BC. In addition, high RUNX3 mRNA expression was found to be correlated with better overall survival and relapse-free survival for all BC patients. Our results strongly support that RUNX3 hypermethylation may play an important role in BC incidence. RUNX3 methylation is a valuable early biomarker for the diagnosis of BC. Further large-scale studies will provide more insight into the role of RUNX3 hypermethylation in the carcinogenesis and clinical diagnosis of BC patients.

Epigenetic mechanisms regulating the development of hepatocellular carcinoma and their promise for therapeutics

Hepatocellular carcinoma (HCC) is one of the most common cancers around the globe and third most fatal malignancy. Chronic liver disorders such as chronic hepatitis and liver cirrhosis often lead to the development of HCC. Accumulation of genetic and epigenetic alterations are involved in the development of HCC. Genetic research sparked by recent developments in next generation sequencing has identified the frequency of genetic alterations that occur in HCC and has led to the identification of genetic hotspots. Emerging evidence suggests that epigenetic aberrations are strongly associated with the initiation and development of HCC. Various important genes encoding tumor suppressors including P16, RASSF1A, DLC-1, RUNX3 and SOCS-1 are targets of epigenetic dysregulation during the development of HCC. The present review discusses the importance of epigenetic regulations including DNA methylation, histone modification and microRNA mediated regulation of gene expression during tumorigenesis and their use as disease biomarkers. Furthermore, these epigenetic alterations have been discussed in relationship with promising therapeutic perspectives for HCC and related cancers.

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.

Association of promoter methylation of RUNX3 gene with the development of esophageal cancer: a meta analysis

BACKGROUND

Runt-related transcription factor 3 (RUNX3) is a member of the runt-domain family of transcription factors. Emerging evidence indicates that RUNX3 is a tumor suppressor gene in several types of human cancers including esophageal cancer. However, the association between RUNX3 promoter methylation and esophageal cancer remains unclear. Here we conducted a systematic review and meta-analysis to quantitatively evaluate the effects of RUNX3 promoter methylation on the incidence of esophageal cancer.

METHODS

A detailed literature search was made on Medline, Pubmed and Web of Science for related research publications written in English and/or Chinese. Methodological quality of the studies was also evaluated. The data were extracted and assessed by two reviewers independently. Analysis of pooled data were performed, the odds ratios (OR) were calculated and summarized respectively.

RESULTS

Final analysis of 558 patients from 9 eligible studies was performed. The result showed that RUNX3 methylation was significantly higher in esophageal cancer than in normal squamous mucosa from the proximal resection margin or esophageal benign lesions (OR = 2.85, CI = 2.01-4.05, P<0.00001). The prevalence of lymph node involvement, tumor size (T1-T2 vs T3-T4) and histological grade was significantly greater in RUNX3-negative cases (RUNX3 unmethylated groups) than in RUNX3-positive cases (OR = 0.25, CI = 0.14-0.43, P<0.00001). RUNX3 methylation was significantly higher in esophageal adenocarcinoma (EAC) than Barrett's esophagus (OR = 0.35, CI = 0.20-0.59, P<0.0001). In addition, the pooled HR for overall survival (OS) showed that decreased RUNX3 expression was associated with worse survival in esophageal cancer (HR = 4.31, 95% CI = 2.57-7.37, P<0.00001).

CONCLUSIONS

The results of this meta-analysis suggest that RUNX3 methylation is associated with an increased risk, progression as well as worse survival in esophageal cancer. RUNX3 methylation, which induces the inactivation of RUNX3 gene, plays an important role in esophageal carcinogenesis.

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.

Novel RNA oligonucleotide improves liver function and inhibits liver carcinogenesis in vivo

Hepatocellular carcinoma (HCC) occurs predominantly in patients with liver cirrhosis. Here we show an innovative RNA-based targeted approach to enhance endogenous albumin production while reducing liver tumor burden. We designed short-activating RNAs (saRNA) to enhance expression of C/EBPα (CCAAT/enhancer-binding protein-α), a transcriptional regulator and activator of albumin gene expression. Increased levels of both C/EBPα and albumin mRNA in addition to a 3-fold increase in albumin secretion and 50% decrease in cell proliferation was observed in C/EBPα-saRNA transfected HepG2 cells. Intravenous injection of C/EBPα-saRNA in a cirrhotic rat model with multifocal liver tumors increased circulating serum albumin by over 30%, showing evidence of improved liver function. Tumor burden decreased by 80% (P = 0.003) with a 40% reduction in a marker of preneoplastic transformation. Since C/EBPα has known antiproliferative activities by way of retinoblastoma, p21, and cyclins, we used messenger RNA (mRNA) expression liver cancer-specific microarray in C/EBPα-saRNA-transfected HepG2 cells to confirm down-regulation of genes strongly enriched for negative regulation of apoptosis, angiogenesis, and metastasis. Up-regulated genes were enriched for tumor suppressors and positive regulators of cell differentiation. A quantitative polymerase chain reaction (PCR) and western blot analysis of C/EBPα-saRNA-transfected cells suggested that in addition to the known antiproliferative targets of C/EBPα, we also observed suppression of interleukin (IL)6R, c-Myc, and reduced STAT3 phosphorylation.

CONCLUSION

A novel injectable saRNA-oligonucleotide that enhances C/EBPα expression successfully reduces tumor burden and simultaneously improves liver function in a clinically relevant liver cirrhosis/HCC model.

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.

Downregulation of microRNA-130a contributes to endothelial progenitor cell dysfunction in diabetic patients via its target Runx3

Dysfunction of endothelial progenitor cells (EPCs) contributes to diabetic vascular disease. MicroRNAs (miRs) have emerged as key regulators of diverse cellular processes including angiogenesis. We recently reported that miR-126, miR-130a, miR-21, miR-27a, and miR-27b were downregulated in EPCs from type II diabetes mellitus (DM) patients, and downregulation of miR-126 impairs EPC function. The present study further explored whether dysregulated miR-130a were also related to EPC dysfunction. EPCs were cultured from peripheral blood mononuclear cells of diabetic patients and healthy controls. Assays on EPC function (proliferation, migration, differentiation, apoptosis, and colony and tubule formation) were performed. Bioinformatics analyses were used to identify the potential targets of miR-130a in EPCs. Gene expression of miR-103a and Runx3 was measured by real-time PCR, and protein expression of Runx3, extracellular signal-regulated kinase (ERK), vascular endothelial growth factor (VEGF) and Akt was measured by Western blotting. Runx3 promoter activity was measured by luciferase reporter assay. A miR-130a inhibitor or mimic and lentiviral vectors expressing miR-130a, or Runx3, or a short hairpin RNA targeting Runx3 were transfected into EPCs to manipulate miR-130a and Runx3 levels. MiR-130a was decreased in EPCs from DM patients. Anti-miR-130a inhibited whereas miR-130a overexpression promoted EPC function. miR-130a negatively regulated Runx3 (mRNA, protein and promoter activity) in EPCs. Knockdown of Runx3 expression enhanced EPC function. MiR-130a also upregulated protein expression of ERK/VEGF and Akt in EPCs. In conclusion, miR-130a plays an important role in maintaining normal EPC function, and decreased miR-130a in EPCs from DM contributes to impaired EPC function, likely via its target Runx3 and through ERK/VEGF and Akt pathways.

The RUNX family in breast cancer: relationships with estrogen signaling

The three RUNX family members are lineage specific master regulators, which also have important, context-dependent roles in carcinogenesis as either tumor suppressors or oncogenes. Here we review evidence for such roles in breast cancer (BCa). RUNX1, the predominant RUNX family member in breast epithelial cells, has a tumor suppressor role reflected by many somatic mutations found in primary tumor biopsies. The classical tumor suppressor gene RUNX3 does not consist of such a mutation hot spot, but it too seems to inhibit BCa; it is often inactivated in human BCa tumors and its haploinsufficiency in mice leads to spontaneous BCa development. The tumor suppressor activities of RUNX1 and RUNX3 are mediated in part by antagonism of estrogen signaling, a feature recently attributed to RUNX2 as well. Paradoxically, however RUNX2, a master osteoblast regulator, has been implicated in various aspects of metastasis in general and bone metastasis in particular. Reciprocating the anti-estrogenic tumor suppressor activity of RUNX proteins, inhibition of RUNX2 by estrogens may help explain their context-dependent anti-metastatic roles. Such roles are reserved to non-osseous metastasis, because ERα is associated with increased, not decreased skeletal dissemination of BCa cells. Finally, based on diverse expression patterns in BCa subtypes, the successful use of future RUNX-based therapies will most likely require careful patient selection.

Genome-wide analysis of DNA methylation in tongue squamous cell carcinoma

Tongue squamous cell carcinoma (TSCC) is one of the most common types of oral cancer; however, its molecular mechanisms remain unclear. In this study, methylated DNA immunoprecipitation (MeDIP) coupled with methylation microarray analysis was performed to screen for aberrantly methylated genes in adjacent normal control and TSCC tissues from 9 patients. Roche NimbleGen Human DNA Methylation 385K Promoter Plus CpG Island Arrays were used to detect 28,226 CpG sites. A total of 1,269 hypermethylated CpG sites covering 330 genes and 1,385 hypomethylated CpG sites covering 321 genes were found in TSCC tissue, compared to the adjacent normal tissue. Furthermore, we chose three candidate genes (FBLN1, ITIH5 and RUNX3) and validated the DNA methylation status by methylation-specific PCR (MS-PCR) and the mRNA expression levels by reverse transcription PCR (RT-PCR). In TSCC tissue, FBLN1 and ITIH5 were shown to be hypermethylated and their expression was found to be decreased, and RUNX3 was shown to be hypomethylated, however, its mRNA expression was found to be increased. In addition, another three genes (BCL2L14, CDCP1 and DIRAS3) were tested by RT-PCR. In TSCC tissue, BCL2L14 and CDCP1 expressions were markedly upregulated, and DIRAS3 expression was significantly downregulated. Our data demonstrated that aberrant DNA methylation is observed in TSCC tissue and plays an important role in the tumorigenesis, development and progression of TSCC.

Stepwise cumulation of RUNX3 methylation mediated by Helicobacter pylori infection contributes to gastric carcinoma progression

BACKGROUND

Helicobacter pylori has been recognized as a definite carcinogen for gastric cancer (GC); however, the pathogenesis of H. pylori infection remains unclear. Runt-related transcription factor 3 (RUNX3) is a candidate tumor suppressor gene whose deficiency is causally related to GC. However, in H. pylori infection-associated GC, the role of RUNX3 has not been studied.

METHODS

The authors used real-time methylation-specific polymerase chain reaction analysis to determine methylation status of the RUNX3 promoter in a spectrum of gastric lesions, including 220 samples of chronic atrophic gastritis, 196 samples of intestinal metaplasia, 134 samples of gastric adenoma, 102 samples of dysplasia, and 202 samples of GC with paired noncancerous mucosa tissues and corresponding blood specimens. The association of abnormal methylation with precancerous gastric lesions was evaluated along with the association between RUNX3 methylation and H. pylori infection, and the concordance of methylation levels was investigated between serum and tissues.

RESULTS

The results indicated that increasing RUNX3 promoter methylation was correlated with distinct stages of GC progression. GC tissues had the highest methylation proportion (75.2%) compared with precancerous gastric lesions, including chronic atrophic gastritis (15.9%), intestinal metaplasia (36.7%), gastric adenoma (41.8%), and dysplasia (54.9%). H. pylori infection, a major risk factor for GC, contributed to the inactivation of RUNX3 in gastric epithelial cells through promoter hypermethylation. The levels of RUNX3 methylation in serum were in significant concordance with the methylation levels observed in GC tissues (P = .887).

CONCLUSIONS

The current findings supported RUNX3 methylation as a risk factors for the carcinogenesis of chronic atrophic gastritis with H. pylori infection and indicated that circulating RUNX3 methylation is a valuable biomarker for the detection of early GC.

Runt-related transcription factor 3 reverses epithelial-mesenchymal transition in hepatocellular carcinoma

Loss or decreased expression of runt-related transcription factor 3 (RUNX3), a tumor suppressor gene involved in gastric and other cancers, has been frequently observed in hepatocellular carcinoma (HCC). The objective of this study was to identify the regulatory mechanism of the epithelial-mesenchymal transition (EMT) by RUNX3 in HCC. Human HCC cell lines, Hep3B, Huh7, HLF and SK-Hep1, were divided into low- and high-EMT lines, based on their expression of TWIST1 and SNAI2, and were used in this in vitro study. Ectopic RUNX3 expression had an anti-EMT effect in low-EMT HCC cell lines characterized by increased E-cadherin expression and decreased N-cadherin and vimentin expression. RUNX3 expression has previously been reported to reduce jagged-1 (JAG1) expression; therefore, JAG1 ligand peptide was used to reinduce EMT in RUNX3-expressing low-EMT HCC cells. Immunohistochemical analyses were performed for RUNX3, E-cadherin, N-cadherin and TWIST1 in 33 human HCC tissues, also divided into low- and high-EMT HCC, based on TWIST1 expression. E-cadherin expression was correlated positively and N-cadherin expression was correlated negatively with RUNX3 expression in low-EMT HCC tissues. Correlations between EMT markers and RUNX3 mRNA expression were analyzed using Oncomine datasets. Similarly, mRNA expression of E-cadherin was also significantly correlated with that of RUNX3 in low-EMT HCC, while mRNA expression of JAG1 was negatively correlated with that of RUNX3. These results suggest a novel mechanism by which loss or decreased expression of RUNX3 induces EMT via induction of JAG1 expression in low-EMT HCC.

Runx1 is a tumor suppressor gene in the mouse gastrointestinal tract

The Runx1 transcription factor plays an important role in tissue homeostasis through its effects on stem/progenitor cell populations and differentiation. The effect of Runx1 on epithelial differentiation of the secretory cell lineage of the colon was recently demonstrated. This study aimed to examine the role of Runx1 in tumor development in epithelial cells of the gastrointestinal tract. Conditional knockout mice that lacked Runx1 expression in epithelial cells of the GI tract were generated. These mice were crossed onto the Apc(Min) background, killed and their intestinal tumor phenotypes were compared with Apc(Min) Runx1 wild-type control mice. Apc-wild-type Runx1-mutant mice were also examined for tumor development. Colons from Runx1 knockout and wild-type mice were used for genome-wide mRNA expression analyses followed by gene-specific quantitative RT-PCR of whole colon and colon epithelium to identify Runx1 target genes. Runx1 deficiency in intestinal epithelial cells significantly enhanced tumorigenesis in Apc(Min) mice. Notably, epithelial Runx1 deficiency in Apc-wild-type mice was sufficient to cause tumor development. Absence of Runx1 was associated with global changes in the expression of genes involved in inflammation and intestinal metabolism, and with gene sets indicative of a metastatic phenotype and poor prognosis. Gene-specific analysis of Runx1-deficient colon epithelium revealed increased expression of genes linked to an expansion of the stem/progenitor cell population. These results identify Runx1 as a novel tumor suppressor gene for gastrointestinal tumors and support a role for Runx1 in maintaining the balance between the intestinal stem/progenitor cell population and epithelial differentiation of the GI tract.