Expression of RUNX3 protein in human esophageal mucosa and squamous cell carcinoma

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.

RUNX3 plays a tumor suppressor role by inhibiting cell migration, invasion and angiogenesis in oral squamous cell carcinoma

Although aberrant expression of Runt-related transcription factor 3 (RUNX3) contributes to tumor progression and metastasis in a number of carcinomas, the status of RUNX3 and its correlation with prognosis in oral squamous cell carcinomas (OSCC) are still controversial. The aim of present study was to investigate the function of RUNX3 in OSCC and the underlying molecular mechanisms. Tissue microarray (TMA) consisting of 232 OSCC specimens was used to detect the expression of RUNX3 by immunohistochemistry method. The effects of RUNX3 restoration on OSCC cell migration and invasion were determined by wound-healing assay, migration and Matrigel cell invasion assays. The antiangiogenic role of RUNX3 was analyzed by testing proliferation and tube formation of human umbilical vascular endothelial cells (HUVECs) cultured with conditioned medium from RUNX3 transfected OSCC cell lines. The activities of MMP-9 and VEGF in RUNX3 transfected OSCC cell lines were examined by western blot and Elisa methods. RUNX3 expression was reduced in OSCC specimens and significantly associated with tumor size (P=0.002), lymph node statue (P=0.0036) and clinical stage (P=0.0001). Negative expression of RUNX3 correlated with worse 5-year overall and disease-specific survival rates (P=0.0348 and P=0.0301, respectively). Furthermore, we found that RUNX3 restoration suppressed cell migration and invasion through downregulating MMP-9 expression and secretion, and exerted antiangiogenic capability by inhibiting VEGF activity in HN6 and Cal27 cells. These findings suggested that RUNX3 played a tumor suppressor role in OSCC by inhibiting cell migration, invasion and angiogenesis, supporting that it could be a potential therapeutic target for OSCC.

Retrospective Study of Adjuvant Chemotherapy Effects on Survival Rate after Three-Field Lymph Node Dissection for Stage IIA Esophageal Cancer

To determine the efficacy of postoperative adjuvant chemotherapy with paclitaxel plus cisplatin (Taxol+DDP, TP therapy) for stage IIA esophageal squamous cell carcinoma (ESCC) and to investigate the expression of RUNX3 in lymph node metastasis-negative esophageal cancer and its relationship with medical prognosis, a retrospective summary of clinical treatment of 143 cases of stage IIA esophageal squamous cell carcinoma patients was made. The patients were divided into two groups, a surgery alone control group (52 patients) and a chemotherapy group that received postoperative TP therapy (91 patients). The disease-free and 5 year survival rates were compared between the groups and a multivariate analysis of prognostic factors was performed. The same analysis was performed for cases classified as RUNX3 positive and negative, with post-operative specimens assessed by immunohistochemistry. Although the disease-free and 5 year survival rates in control and chemotherapy groups did not significantly differ and there was no significance in RUNX3 negative cases, postoperative adjuvant chemotherapy in the chemotherapy group was shown to improve disease-free and 5 year survival rate compared to the control group in RUNX3 positive cases. On Cox regression multivariate analysis, postoperative adjuvant chemotherapy (P<0.01) was an independent prognostic factor for RUNX3 positive cases, suggesting that postoperative TP may be effective as adjuvant chemotherapy for stage IIA esophageal cancer patients with RUNX3 positive lesions.

Investigation of methylation and protein expression of the Runx3 gene in colon carcinogenesis

In the present study, the methylation and protein expression of the runt-related transcription factor 3 (Runx3) gene was detected in sporadic colorectal cancer, colonic adenoma and normal colon tissue to evaluate their clinical significance in colorectal carcinogenesis. A total of 34 colonic cancer specimens, 34 colonic adenoma specimens and 34 normal colonic tissue specimens were used in the study. The CpG island methylation status of the Runx3 gene was detected by methylation-specific polymerase chain reaction and the protein expression of Runx3 was detected by immunohistochemistry. The results showed that the rates of methylation of the Runx3 gene in colonic cancer and colonic adenomas were significantly higher than that in the normal colonic tissue (23.5, 20.6 vs. 0.0%; P<0.05). There was no significant difference in the percentage of methylation of the Runx3 gene between colonic adenoma and colonic cancer (P>0.05). The positive percentage of Runx3 protein expression was significantly lower in colonic cancer compared with colonic adenoma and normal tissue (17.7 vs. 61.8, 76.5%; P<0.05). Methylation of the promoter CpG islands of the Runx3 gene is an important genetic event of colon carcinogenesis and may be associated with an altered protein level of Runx3.

Overexpression of RUNX3 inhibits malignant behaviour of Eca109 cells in vitro and vivo

Runt-related transcription factor 3 (RUNX3) is a tumor suppressor gene whose reduced expression may play an important role in the development and progression of esophageal squamous cell cancer (ESCC). The aim of this study was to investigate the clinical relevance of RUNX3 in ESCC patients and effects of overexpression on biological behaviour of Eca109 cells in vitro and in vivo. Immunohistochemistry was performed to detect the clinical relevance of RUNX3 and lymph node metastasis in 80 ESCC tissues and 40 non-cancerous tissues using the SP method. RT-PCR and Western blotting were applied to assess the RUNX3 level and verify the Eca109 cell line with stable overexpression. Localization of RUNX3 proteins was performed by cell immunofluorescence. CCK-8 and Scrape motility assays were used to determine proliferation and migration and the TUNEL assay to analyze cell apoptosis. Invasive potential was assessed in cell transwell invasion experiments. In nude mice, tumorigenesis in vivo was determined. Results showed decreased expression of RUNX3 in esophageal tissue to be significantly related to lymph node metastasis (LNM) (P<0.01). In addition, construction of a recombinant lentiviral vector and transfection into the human ESCC cell line Eca109 demonstrated that overexpression could inhibit cell proliferation, migration and invasion, and induce apoptosis. The in vivo experiments in mice showed tumorigenicity and invasiveness to be significantly reduced. Taken together, our studies indicate that underexpression of RUNX3 in human ESCC tissue is significantly correlated with progression. Restoration of RUNX3 expression significantly inhibits ESCC cells proliferation, migration, invasion and tumorigenesis.

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.

Molecular mechanisms of Barrett's esophagus

Barrett's esophagus (BE) is defined as the metaplastic conversion of esophageal squamous epithelium to intestinalized columnar epithelium. As a premalignant lesion of esophageal adenocarcinoma (EAC), BE develops as a result of chronic gastroesophageal reflux disease (GERD). Many studies have been conducted to understand the molecular mechanisms of this disease. This review summarizes recent results involving squamous and intestinal transcription factors, signaling pathways, stromal factors, microRNAs, and other factors in the development of BE. A conceptual framework is proposed to guide future studies. We expect elucidation of the molecular mechanisms of BE to help in the development of improved management of GERD, BE, and EAC.

Significance of methylation and protein expression of the Runx3 gene in colon carcinogenesis

AIM: To detect the methylation and protein expression of the Runx3 gene in sporadic colorectal cancer (SCRC), colonic adenoma, and normal colon tissue and to evaluate their clinical significance in colorectal carcinogenesis.

METHODS: Thirty-four colonic cancer specimens, 34 colonic adenoma specimens, and 34 normal colonic tissue specimens were used in this study. The CpG island methylation status of the Runx3 gene was detected by methylation-specific PCR in these specimens. and the protein expression of Runx3 was detected by immunohistochemistry.

RESULTS: The rates of methylation of the Runx3 gene in colonic cancer and colonic adenoma were significantly higher than that in normal colonic tissue (23.5%, 20.6% vs 0.0%, both P < 0.05). There was no significant difference in the rate of methylation of the Runx3 gene between colonic adenoma and colonic cancer (P > 0.05). The positive rate of Runx3 protein expression was significantly lower in colonic cancer than in colonic adenoma and normal tissue (17.7% vs 61.8%, 76.5%, both P < 0.05).

CONCLUSION: Methylation of the promoter CpG islands of the Runx3 gene is an important genetic event of colon carcinogenesis and may be associated with altered protein expression of Runx3.

Oncogenic role of RUNX3 in head and neck cancer

Cumulative evidences show that Runt-related transcription factor 3 (RUNX3) has a tumor suppressive role in various cancers. In particular, RUNX3 appears to be an important component of the transforming growth factor-β (TGF-β)-induced tumor suppression pathway. Contrary to reports on this tumor suppressive role of RUNX3, RUNX3 can also function as an oncogene when overexpressed. Recently, we found that RUNX3 overexpression was frequently observed and was well correlated with malignant behaviors in head and neck cancer, which is one of the most common types of human cancer. Moreover, it has been revealed that RUNX3 overexpression promoted cell growth and inhibited apoptosis in head and neck cancer cells. This review introduces the oncogenic role of RUNX3 in certain types of cancer including head and neck cancer.

Molecular pathology of RUNX3 in human carcinogenesis

A major goal of molecular biology is to elucidate the mechanisms underlying cancer development and progression in order to achieve early detection, better diagnosis and staging and novel preventive and therapeutic strategies. We feel that an understanding of Runt-related transcription factor 3 (RUNX3)-regulated biological pathways will directly impact our knowledge of these areas of human carcinogenesis. The RUNX3 transcription factor is a downstream effector of the transforming growth factor-beta (TGF-beta) signaling pathway, and has a critical role in the regulation of cell proliferation and cell death by apoptosis, and in angiogenesis, cell adhesion and invasion. We previously identified RUNX3 as a major gastric tumor suppressor by establishing a causal relationship between loss of function and gastric carcinogenesis. More recently, we showed that RUNX3 functions as a bona fide initiator of colonic carcinogenesis by linking the Wnt oncogenic and TGF-beta tumor suppressive pathways. Apart from gastric and colorectal cancers, a multitude of epithelial cancers exhibit inactivation of RUNX3, thereby making it a putative tumor suppressor in human neoplasia. This review highlights our current understanding of the molecular mechanisms of RUNX3 inactivation in the context of cancer development and progression.

Regulation of RUNX3 tumor suppressor gene expression in cutaneous melanoma

PURPOSE

RUNX3 is a known tumor suppressor gene in several carcinomas. Aberration in RUNX3 expression has not been described for cutaneous melanoma. Therefore, we assessed the expression of RUNX3 in cutaneous melanoma and its regulatory mechanisms relative to tumor progression.

EXPERIMENTAL DESIGN

The expression of RUNX3 mRNA and miR-532-5p (microRNA) was assessed in melanoma lines and in primary and metastatic melanoma tumors.

RESULTS

RUNX3 mRNA expression was down-regulated in 11 of 11 (100%) metastatic melanoma lines relative to normal melanocytes (P < 0.001). Among 123 primary and metastatic melanoma tumors and 12 normal skin samples, RUNX3 expression was significantly down-regulated in primary melanomas (n = 82; P = 0.02) and in melanoma metastasis (n = 41; P < 0.0001) versus normal skin (n = 12). This suggested that RUNX3 down-regulation may play a role in the development and progression of melanoma. RUNX3 promoter region hypermethylation was assessed as a possible regulator of RUNX3 expression using methylation-specific PCR. Assessment of RUNX3 promoter region methylation showed that only 5 of 17 (29%) melanoma lines, 2 of 52 (4%) primary melanomas, and 5 of 30 (17%) metastatic melanomas had hypermethylation of the promoter region. A microRNA (miR-532-5p) was identified as a target of RUNX3 mRNA sequences. miR-532-5p expression was shown to be significantly up-regulated in melanoma lines and metastatic melanoma tumors relative to normal melanocytes and primary melanomas, respectively. To investigate the relation between RUNX3 and miR-532-5p, anti-miR-532-5p was transfected into melanoma lines. Inhibition of miR-532-5p up-regulated both RUNX3 mRNA and protein expression.

CONCLUSIONS

RUNX3 is down-regulated during melanoma progression and miR-532-5p is a regulatory factor of RUNX3 expression.