Metastasis-associated protein 1 (MTA1) overexpression is closely associated with shorter disease-free interval after complete resection of histologically node-negative esophageal cancer

Expression and Prognostic Significance of Metastasis-Associated Protein 1 in Gastrointestinal Cancer

Background

Metastasis-associated protein 1 (MTA1) has been considered as a transcriptional regulator, which is significantly related to the prognosis in various types of tumors. However, whether MTA1 is a potential prognostic index of gastrointestinal cancer (GIC) remains controversial. The current meta-analysis was performed to evaluate the role of MTA1 expression in the prediction of the clinicopathological features and survival in GIC cases. And the results of gastric cancer were verified by immunohistochemistry (IHC).

Methods

Eligible studies assessing the relationship between MTA1 and GIC by IHC were searched in the PubMed, Cochrane, Ovid, Web of Science and CNKI databases by various search strategies. The STATA 16.0 software was applied to gather data and to analyze the potential relationship between MTA1 and GIC. The expression level of MTA1 was examined in 80 GC samples by IHC assay. SPSS 20.0 was applied for statistical analysis, and the survival curves were calculated by the Kaplan-Meier method. The data of 95% CI was displayed as “[a-b]”.

Results

According to the meta-analysis, the expression level of MTA1 was tightly associated with the tumor size (OR=1.82 [1.16–2.84], P=0.009), tumor tissue differentiation (OR=1.71 [1.24–2.37], P=0.001), depth of invasion (OR=3.12 [2.55–3.83], P<0.001), lymphatic metastasis (OR=2.99 [2.02–4.43], P<0.001), distant metastasis (OR=4.66 [1.13–19.24], P=0.034), TNM stage (OR=4.28 [2.76–6.63], P<0.001). In addition, MTA1 played the negative effects in 1- (RR=2.48 [1.45–4.25], P=0.001), 3- (RR=1.66 [1.30–2.11], P<0.001) and 5-year (RR=1.73 [1.37–2.20], P<0.001). Study in subgroup, grouped by language and tumor type, we reached similar conclusions. Further validation by IHC yielded similar conclusions. Tumor size (P=0.008), lymph node metastasis (P=0.007) and distant metastasis (P=0.023) significantly accompanied with higher expression of MAT1 in GC cases. Besides, the expression level of MTA1 was statistically significantly correlated with OS in GC cases (HR=2.061 [1.066–3.986], P=0.032), which suggested that MTA1 might be an independent prognostic marker for GC. Finally, we verified the correlation between the expression level of MTA1 and prognosis of GC in 80 GC samples.

Conclusions

MTA1 is tightly associated with metastasis-related factors and may constitute a promising prognostic factor of GIC.

Prognostic and clinical significance of metastasis-associated gene 1 overexpression in solid cancers: A meta-analysis

BACKGROUND

In the past 2 decades, metastasis-associated gene 1 (MTA1) has attracted attention for its close association with cancer progression and its roles in chromatin remodeling processes, making it a central gene in cancer. The present meta-analysis was performed to assess MTA1 expression in solid tumors.

MATERIALS AND METHODS

This analysis identified studies that evaluated the relationship between MTA1 expression and clinical characteristics or prognosis of patients with solid tumors via the PubMed, Cochrane Library, and Embase electronic databases. Fixed-effect and random-effect meta-analytical techniques were used to correlate MTA1 expression with outcome measures. The outcome variables are shown as odds ratio (OR) or hazard ratio (HR) with 95% confidence interval (CI).

RESULTS

Analysis of 40 cohort studies involving 4564 cancer patients revealed a significant association of MTA1 overexpression with tumor patient age (>50 vs. <50 years: combined OR 0.73, 95% CI 0.57-0.94), tumor grade (G3/4 vs. G1/2: combined OR 1.94, 95% CI 1.48-2.53), tumor size (>3 cm vs. <3 cm: combined OR 2.35, 95% CI 1.73-3.19), T stage (T3/4 vs. T1/2: combined OR 2.11, 95% CI 1.74-2.56), lymph node metastasis (yes vs. no: combined OR 2.92, 95% CI 2.26-3.75), distant metastasis (yes vs. no: combined OR 2.26, 95% CI 1.42-3.59), TNM stage (III/IV vs. I/II: combined OR 2.50, 95% CI 1.84-3.38), vascular invasion (yes vs. no: combined OR 2.26, 95% CI 1.92-3.56), and poor overall survival time (HR 1.83; 95% CI: 1.53-2.20; P = .000).

CONCLUSIONS

Our analyses demonstrate that MTA1 was an effective predictor of a worse prognosis in tumor patients. Moreover, MTA1 may play important role in tumor progression and outcome, and targeting MTA1 may be a new strategy for anti-cancer therapy.

Effects of microRNA-183 on epithelial-mesenchymal transition, proliferation, migration, invasion and apoptosis in human pancreatic cancer SW1900 cells by targeting MTA1

OBJECTIVE

This study aims to explore effects of miR-183 on epithelial-mesenchymal transition (EMT) and invasion by targeting MTA1 in human pancreatic cancer (PC) cells.

METHODS

Totally, 108 PC patients admitted in Wenzhou Central Hospital and Wenzhou People's Hospital, The Dingli Clinical Institute of Wenzhou Medical University from March 2010 to March 2014 were enrolled. qRT-PCR and immunohistochemistry were applied to examine expression of MTA1 mRNA and protein. Samples were divided into 6 groups: blank, NC, miR-183 mimics, miR-183 inhibitors, MTA1-siRNA and miR-183 inhibitors +MTA1-siRNA groups. CCK8 method was employed for determining cell proliferation rate, flow cytometry for cell apoptosis rate, scratch test for cell migration and Transwell assay for cell invasion. qRT-PCR and Western blotting were used to determine expression of MTA1, E-cadherin and Vimentin mRNA and protein.

RESULTS

Positive expression rate of MTA1 was upregulated in PC tissues, and expression of miR-183 and MTA1 was associated with differentiation, migration, tumor size, TNM. The miR-183 mimics and MTA1-siRNA groups showed a decrease in proliferation, migration and invasion, whereas increased apoptosis, in comparison with blank and NC groups, as expression of MTA1 and Vimentin mRNA and protein were reduced, expression of E-cadherin mRNA and protein was elevated. Compared to blank and NC groups, the miR-183 inhibitors group exhibited enhanced proliferation, migration and invasion and inhibited apoptosis; increased expressions of MTA1 and Vimentin mRNA and protein and decreased expressions of E-cadherin mRNA and protein.

CONCLUSION

Our study supported that miR-183 could repress EMT and invasion of human PC cells through inhibition of MTA1 expression.

Role of metastasis-associated protein 1 in prognosis of patients with digestive tract cancers: A meta-analysis

OBJECTIVES

Metastasis-associated protein 1 (MTA1) is a transcriptional regulator and significantly associated with prognosis of patients with cancer. However, its role as a potential prognostic marker in digestive tract cancer (DTC) is controversial. In this study, a meta-analysis was conducted to evaluate the MTA1 expression as a predictor of clinicopathology and survival of patients with DTC.

METHODS

We searched PubMed, Ovid, Web of Science and Cochrane databases using multiple search strategies for eligible studies. STATA 11.0 software was used to pool the data and analyze the association, odds ratios (ORs) and 95% confidence intervals (CIs) were used to measure the strength of the association. Furthermore, the Newcastle-Ottawa scale was used to evaluate the quality of eligible studies.

RESULTS

MTA1 overexpression was strongly associated with depth of invasion (OR = 1.88, 95%CI: 1.05-3.37, P = 0.03), lymph node metastasis (OR = 2.30, 95%CI: 1.76-3.01, P<0.001), vascular invasion (OR = 2.02, 95%CI: 1.40-2.91, P<0.001) and TNM stage (OR = 2.78, 95%CI: 1.63-4.74, P<0.001), and was related to 1- (RR = 1.84, 95%CI: 1.18-2.89, P = 0.008), 3- (RR = 1.74, 95%CI: 1.32-2.30, P<0.001) and 5-year (RR = 1.64, 95%CI: 1.18-2.27, P = 0.003) OS. Further, MTA1 was associated with 1- (RR = 4.16, 95%CI: 1.35-12.81, P = 0.01), 3- (RR = 1.90, 95%CI: 1.02-3.53, P = 0.04) and 5- (RR = 2.17, 95%CI: 1.41-3.32, P<0.001) year DFS. In subgroup analyses based on study quality and tumor type, MTA1 overexpression was obviously related to clinical parameters, such as lymph node metastasis and TNM stage, and was also associated with prognosis of patients with gastrointestinal or esophageal cancer.

CONCLUSIONS

MTA1 expression is strongly correlated with metastasis-related variables, and represents a promising prognostic factor in DTC.

TNFAIP8 overexpression: a potential predictor of lymphatic metastatic recurrence in pN0 esophageal squamous cell carcinoma after Ivor Lewis esophagectomy

Esophageal squamous cell carcinoma (ESCC) has a poor prognosis due to high lymphatic metastatic recurrence rates after Ivor Lewis esophagectomy. We sought to investigate the correlation between tumor necrosis factor alpha-induced protein 8 (TNFAIP8) expression and postoperative lymphatic recurrence in patients with pN0 ESCC. One hundred twenty-two patients with pN0 ESCC undergoing Ivor Lewis esophagectomy were enrolled in this study. TNFAIP8 overexpression was found in 73 (59.8 %) tumor specimens. The 3-year lymphatic metastatic recurrence rate among TNFAIP8-overexpressing patients was significantly higher than in TNFAIP8-negative patients (p = 0.003). Multivariate Cox regression identified TNFAIP8 overexpression as an independent risk factor for lymphatic recurrence (p = 0.048). TNFAIP8 messenger RNA (mRNA) levels were significantly higher in patients with lymphatic recurrence than in patients without tumor recurrence (p = 0.019). Stable silencing of TNFAIP8 expression in ESCC-derived cells (Eca109) reduced proliferation, motility, and invasion and induced apoptosis. In addition, transient silencing of TNFAIP8 expression decreased cell motility and invasion and increased apoptosis in a second ESCC-derived cell line (KYSE150). Taken together, these findings suggest that TNFAIP8 overexpression is a potential biomarker to identify pN0 ESCC patients at higher risk of lymphatic recurrence who may benefit from adjuvant therapy.

Overexpression of IFITM3 predicts the high risk of lymphatic metastatic recurrence in pN0 esophageal squamous cell carcinoma after Ivor-Lewis esophagectomy

Background. Recent studies have shown that the aberrant expression of IFITM3 is implicated in the lymph node metastasis of many malignancies. Our research aimed to investigate the expression of IFITM3 in pathological N0 (pN0) esophageal squamous cell carcinoma (ESCC) and its relationship with lymph node metastatic recurrence. Methods. Immunohistochemistry (IHC) was used to examine the expression profile of IFITM3 in 104 pairs of samples. Each pair consisted of ESCC tissue and its adjacent normal mucosa (ANM). This aberrant expression was verified by reverse transcription-polymerase chain reaction (RT-PCR) with 20 tumor specimens with strong immunostaining and their mucosal tissues. In addition, 20 samples of low expression tissues and their ANMs were evaluated. Moreover, the correlations between the IFITM3 expression level and the clinicopathological variables, recurrence risk and overall survival (OS) of patients were analyzed. Results. Both IHC and RT-PCR demonstrated that the IFITM3 expression level was significantly higher in tumor tissue than in ANM. Statistical analysis showed a significant correlation of IFITM3 expression with the T status of esophageal cancer (p = 0.015). In addition, IFITM3 overexpression was demonstrated to be not only an important risk factor of lymphatic metastatic recurrence but a significant prognostic factor in pN0 ESCC (p < 0.005). Conclusions. Even pN0 ESCC patients will still experience lymphatic metastatic recurrence. The IFITM3 gene could be a predictor of lymphatic metastatic recurrence in pN0 ESCC after Ivor-Lewis esophagectomy.

Unravelling the Complexity and Functions of MTA Coregulators in Human Cancer

Since the initial recognition of the metastasis-associated protein 1 (MTA1) as a metastasis-relevant gene approximately 20 years ago, our appreciation for the complex role of the MTA family of coregulatory proteins in human cancer has profoundly grown. MTA proteins consist of six family members with similar structural units and act as central signaling nodes for integrating upstream signals into regulatory chromatin-remodeling networks, leading to regulation of gene expression in cancer cells. Substantial experimental and clinical evidence demonstrates that MTA proteins, particularly MTA1, are frequently deregulated in a wide range of human cancers. The MTA family governs cell survival, the invasive and metastatic phenotypes of cancer cells, and the aggressiveness of cancer and the prognosis of patients with MTA1 overexpressing cancers. Our discussion here highlights our current understanding of the regulatory mechanisms and functional roles of MTA proteins in cancer progression and expands upon the potential implications of MTA proteins in cancer biology and cancer therapeutics.

MTA1 downregulation inhibits malignant potential in a small cell lung cancer cell line

As a component of the nuclear remodeling and deacetylation complex (NuRD complex), metastasis-associated gene 1 (MTA1) has been reported to play a key role in cancer malignancy. However, whether MTA1 functions in small cell lung cancer (SCLC) malignant behavior and whether it is feasible to be used as a therapeutic target have not been evaluated. The present study aimed to investigate the effects of MTA1 downregulation on SCLC malignancy. First we demonstrated the overexpression of MTA1 in SCLC specimens. After knocking down the MTA1 level by specific siRNA sequence, the biological consequences on proliferation, migration, invasion and apoptosis were evaluated. The results showed that MTA1 silencing had potent suppressive effects on SCLC proliferation, migration and invasion. Apoptosis but not cell cycle arrest was induced in the MTA1-silenced SCLC cells. In summary, MTA1 plays a critical role in regulating the malignant behaviors of SCLC. Depleting MTA1 level may be an effective strategy by which to suppress SCLC growth and metastasis in future biotherapeutic attempts.

MTA1--a stress response protein: a master regulator of gene expression and cancer cell behavior

Gene mutation's role in initiating carcinogenesis has been controversial, but it is consensually accepted that both carcinogenesis and cancer metastasis are gene-regulated processes. MTA1, a metastasis-associated protein, has been extensively researched, especially regarding its role in cancer metastasis. In this review, I try to elucidate MTA1's role in both carcinogenesis and metastasis from a different angle. I propose that MTA1 is a stress response protein that is upregulated in various stress-related situations such as heat shock, hypoxia, and ironic radiation. Cancer cells are mostly living in a stressful environment of hypoxia, lack of nutrition, and immune reaction attacks. To cope with all these stresses, MTA1 expression is upregulated, plays a role of master regulator of gene expression, and helps cancer cells to survive and migrate out of their original dwelling.

Molecular functions and significance of the MTA family in hormone-independent cancer

The members of the metastasis-associated protein (MTA) family play pivotal roles in both physiological and pathophysiological processes, especially in cancer development and metastasis, and their role as master regulators has come to light. Due to the fact that they were first identified as crucial factors in estrogen receptor-mediated breast cancer metastasis, most of the early studies focused on their hormone-dependent functions. However, the accumulating evidence shows that the members of MTA family are deregulated in most, if not all, the cancers studied so far. Therefore, the levels as well as the activities of the MTA family members are widely accepted as potential biomarkers for diagnosis, prognosis, and predictors of overall survival. They function differently in different cancers with specific mechanisms. p53 and HIF-1α appear to be the respectively common upstream and downstream regulator of the MTA family in both development and metastasis of a wide spectrum of cancers. Here, we review the expression and clinical significance of the MTA family, focusing on hormone-independent cancers. To illustrate the molecular mechanisms, we analyze the MTA family-related signaling pathways in different cancers. Finally, targeting the MTA family directly or the pathways involved in the MTA family indirectly could be invaluable strategies in the development of cancer therapeutics.

Properties and clinical relevance of MTA1 protein in human cancer

Among the genes that were found to be abundantly overexpressed in highly metastatic rat cell lines compared to poorly metastatic cell lines, we identified a completely novel complementary DNA (cDNA) without any homologous or related genes in the database in 1994. The full-length cDNA of this rat gene was cloned, sequenced, and named metastasis-associated gene 1 (mta1), and eventually, its human cDNA counterpart, MTA1, was also cloned and sequenced by our group. MTA1 has now been identified as one of the members of a gene family (MTA gene family) and the products of the MTA genes, the MTA proteins, are transcriptional co-regulators that function in histone deacetylation and nucleosome remodeling and have been found in nuclear histone remodeling complexes. Furthermore, MTA1 along with its protein product MTA1 has been repeatedly and independently reported to be overexpressed in a vast range of human cancers and cancer cell lines compared to non-cancerous tissues and cell lines. The expression levels of MTA1 correlate well with the malignant properties of human cancers, strongly suggesting that MTA1 and possibly other MTA proteins (and their genes) could be a new class of molecular targets for cancer diagnosis and therapy.

Clinical implications of MTA proteins in human cancer

Metastasis-associated gene or metastasis tumor antigen 1 (MTA1) is a new member of cancer progression-related gene family. It was first identified in rat mammary adenocarcinoma and later recognized as an important constituent of nucleosomal remodeling complex (NuRD), displaying dual regulatory functions as a co-repressor and co-activator for a large number of genes. Chromatin remodelers are ATP-dependent multi-protein chromatin modifying machines. These complexes alter the nucleosome positioning regulating the accessibility of genomic DNA to various transcription factors and thus modulate eukaryotic gene transcription. Since its identification two decades ago, MTA1 has been reported to be overexpressed in many cancers. Moreover, its overexpression has also been correlated with transformation and tumor progression. Furthermore, MTA1 has been shown to modulate the response of several tumor suppressor genes like p53 and oncogenes like c-myc. Taken together, current literature suggests that MTA proteins, especially MTA1, act as a master co-regulatory molecule involved in the carcinogenesis and progression of various malignant tumors. The primary focus of this review is to provide an overview of the MTA proteins with special emphasis on its role in cancer and use as a marker for cancer progression and potential target for therapy.

Subcellular localization of MTA proteins in normal and cancer cells

The subcellular localization of a protein is closely linked to and indicates its function. The metastatic tumor antigen (MTA) family has been under continuous investigation since its identification two decades ago. MTA1, MTA2, and MTA3 are the main members of the MTA family. MTA1, as the representative member of this family, has been shown to be widely expressed in both embryonic and adult tissues, as well as in normal and cancerous conditions, indicating that MTA1 has functions both in physiological and pathological contexts. MTA1 is expressed at a higher level in most cancers than in their normal tissue counterparts. Even in normal cells, MTA1 levels vary a great deal from tissue to tissue. Importantly, MTA1 shows a multiple localization pattern in the cell, as do MTA2 and MTA3. Different MTA components in different subcellular compartments may exert different molecular functions in the cell. Previous studies revealed that MTA1 and MTA2 are predominately localized to the nucleus, while MTA3 is observed in both the nucleus and cytoplasm. Recent studies have reported that MTA1 is located in the nucleus, cytoplasm, and the nuclear envelope. In the nucleus, MTA1 dynamically interacts with chromatin in a MTA1-K532 methylation-dependent manner, whereas cytoplasmic MTA1 binds to the microtubule skeleton. MTA1 also shows a dynamic distribution during the cell cycle. Further investigations are needed to identify the exact subcellular localizations of MTA proteins. We review the sub-cellular localization patterns of the MTA family members and give a comprehensive overview of their respective molecular activities in multiple contexts.

Metastasis-associated protein 1 as a new prognostic marker for solid tumors: a meta-analysis of cohort studies

Metastasis-associated protein 1 (MTA1) is a molecular marker in various solid tumors that has recently been investigated. The prognostic significance of MAT1 expression remains controversial. In this work, we aimed to determine the relationship between immunohistochemistry-detected MAT1 expression and survival of patients with solid tumors by conducting a meta-analysis of cohort studies. Relevant studies were identified via an electronic database search updated on October 28, 2013. We included cohort studies that reported hazard ratios (HRs) or odds ratios (ORs) with 95 % confidence intervals (CIs) to determine the association of high MTA1 expression with overall survival (OS) and clinicopathological characteristics. Heterogeneity was quantified using I (2) statistics, and publication bias was evaluated using funnel plots. Sensitivity analysis was conducted to evaluate the robustness of meta-analysis findings. We identified 16 cohort studies that focused on MTA1 overexpression and prognosis involving 2,253 cancer patients. Overall, the combined HR for OS was 1.85 (95 % CI: 1.55-2.28, P<0.001). Omission of any single study had no significant effect on the pooled HR estimate. When the studies were stratified by tumor type, similar results of poor prognosis were observed in non-small cell lung cancer (HR=2.05, 95 % CI: 1.14-3.68, P=0.016) and esophageal squamous cell carcinoma (HR=1.86, 95 % CI: 1.44-2.39, P<0.001). Moreover, multivariate survival analysis showed that MTA1 overexpression was an independent predictor of poor prognosis (HR=1.90, 95 % CI: 1.53-2.37, P<0.001). In addtional, MTA1 overexpression was significantly associated with tumor size (OR=2.72, 95 % CI=1.44-5.14, P=0.002), tumor stage (OR=2.44, 95 % CI=1.67-3.57, P<0.001), depth of invasion (OR=2.63, 95 % CI=1.74-3.97, P<0.001), and lymph node metastasis (OR=2.57, 95 % CI=1.57-4.19, P<0.001). However, when age, sex, and tumor differentiation were considered, no obvious association was observed. This study provides a comprehensive examination of the literature available on the association of MTA1 overexpression with OS and some clinicopathological features in solid tumors. Meta-analysis results provide evidence that MTA1 may be a new indicator of poor cancer prognosis. Considering the limitations of the eligible studies, other large-scale prospective trials must be conducted to clarify the prognostic value of MTA1 in predicting cancer survival.

Metastasis-associated protein 1 promotes tumor invasion by downregulation of E-cadherin

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors. Upregulation of metastasis-associated protein 1 (MTA1) has been reported to contribute to the development of esophageal squamous cell carcinoma. Therefore, the objective of our study was to identify the molecular mechanisms of MTA1 underlying the invasion and metastasis of ESCC. We overexpressed MTA1 in ESCC cells to examine the role of MTA1 in the regulation of the cell invasion. In addition, using luciferase reporter assay and electrophoretic mobility shift assays, we evaluated the binding of MTA1 to the promoter of E-cadherin. We found that MTA1 overexpression promotes invasiveness of the human esophageal carcinoma cell line EC-9706. This effect was accompanied by downregulation of the epithelial cell marker E-cadherin and upregulation of vimentin and MMP-9 luciferase reporter assays showed that MTA1 inhibited the promoter activity of E-cadherin and that this was dependent on Snail, Slug and HDAC1. We also found that Snail and Slug bound the E-boxes in the promoter of E-cadherin and recruited MTA1 and HDAC1 to suppress E-cadherin expression, as confirmed by electrophoretic mobility shift and chromatin immunoprecipitation assays. MTA1 promotes tumor invasion by downregulation of E-cadherin. These results demonstrate a novel role for MTA1 in the regulation of esophageal squamous cell carcinoma invasion and provide insight into the mechanisms involved in this process.

RBP2 induces epithelial-mesenchymal transition in non-small cell lung cancer

RBP2 has been found to actively participate in cancer progression. It inhibits the senescence of cancer cells, mediates cancer cell proliferation and promotes cancer metastasis. It is also essential to drug tolerance. However, the effects of RBP2 on epithelial-mesenchymal transition are still unknown. In this study, we analyzed the effects of RBP2 on epithelial-mesenchymal transition in non-small cell lung cancer. The results showed that RBP2 down-regulated the expression of E-cadherin by inhibiting the promoter activity of E-cadherin and up-regulated the expression of N-cadherin and snail via the activation of Akt signaling, and the overexpression of RBP2 induced epithelial-mesenchymal transition in non-small cell lung cancer cells. Our study further indicated that RBP2 may be a potential target for anti-lung cancer therapy.

Close association of metastasis-associated protein 1 overexpression with increased angiogenesis and poor survival in patients with histologically node-negative gastric cancer

BACKGROUND

Although metastasis-associated protein 1 (MTA1) has been recently demonstrated as a potent angiogenesis-promoting factor in various malignant tumors, its angiogenic property in gastric cancer (GC) remains unclear. This study has detected the expression of MTA1 protein in surgically resected tissues of pathologic N0 (pN0) GC and further investigated its relation with other clinicopathologic factors and tumor angiogenesis and prognosis.

METHODS

MTA1 protein expression was detected immunohistochemically in 111 pN0 GC specimens. Its correlations with clinicopathologic factors and tumor prognosis were evaluated. The intratumoral microvessel density (MVD) was assessed based on CD105 antigen immunoreactivity and analyzed for correlation with MTA1 protein expression.

RESULTS

Overexpression of MTA1 was detected in 36.04 % of patients and exhibited a significant association with tumor size and MVD. Survival analysis demonstrated that both overall (OS) and disease-free (DFS) survivals in patients overexpressing MTA1 were significantly poorer than those without MTA1 overexpression 5 years after the operation (both p < 0.001). Multivariate survival analysis demonstrated that MTA1 overexpression was an independent prognosticator for unfavorable OS and DFS (p < 0.001, respectively).

CONCLUSIONS

MTA1 overexpression is frequently observed in pN0 GC patients and is significantly associated with increased angiogenesis and poor prognosis. Detection of MTA1 protein expression may help predict the relapse and prognosis of pN0 GC. Also, MTA1 protein may form a novel target for antiangiogenic therapy.

Molybdenum increases chemosensitivity of ECA-109 cells to cisplatin and cisplatin-induced inhibition of p75NTR expression in esophageal stem cells

AIM: To investigate the effect of molybdenum on the chemosensitivity of esophageal cancer ECA-109 cells to cisplatin and expression of p75^NTR in esophageal stem cells.

METHODS: ECA-109 cells were divided into four groups: blank control group, cisplatin group, molybdenum group, cisplatin plus molybdenum group. Cell proliferation was measured by methyl thiazolyl tetrazolium (MTT) assay. The expression of p75^NTR in human esophageal stem cells was examined by flow cytometry.

RESULTS: Cisplatin reduced the percentage of p75^NTR-positive cells and the proliferation of ECA-109 cells in a dose-dependent manner. Treatment with molybdenum alone had no significant influence on the proliferation of ECA-109 cells and the percentage of p75^NTR-positive cells. However, treatment with molybdenum significantly enhanced the chemosensitivity of esophageal cancer ECA-109 cells to cisplatin and cisplatin-induced inhibition of p75^NTR expression in esophageal stem cells when compared to cells incubated with cisplatin alone or blank control cells (all P < 0.05).

CONCLUSION: Molybdenum can increase the inhibitory effect of cisplatin on the proliferation of ECA-109 cells, which provides an experimental basis for the use of molybdenum as adjuvant chemotherapeutic agent for esophageal cancer.

Metastasis-associated protein 1 nuclear expression is closely associated with tumor progression and angiogenesis in patients with esophageal squamous cell cancer

BACKGROUND

The purposes of the present study were to detect the expression of metastasis-associated protein 1 (MTA1) in patients with esophageal squamous cell cancer (ESCC), and to evaluate the relevance of MTA1 protein expression to the tumor progression, angiogenesis, and prognosis.

METHODS

Both MTA1 protein and intratumoral microvessels were examined by immunohistochemical staining in 131 ESCC patients who successfully underwent subtotal esophagectomy and esophagogastric anastomosis at Qilu Hospital between Jan 2004 and Dec 2005. Intratumoral microvessel density (MVD) was recorded by counting CD-34 positive immunostained endothelial cells. All statistical analyses were performed with SPSS 13.0 statistical software.

RESULTS

High expression of MTA1 protein was detected in 57 cases and significantly correlated with tumor invasion depth (P = 0.041), lymph node metastasis (P = 0.021), pathologic stage (P = 0.003), and MVD (P = 0.044). Survival analysis showed that patients with MTA1 protein high expression had significantly poor overall 5-year survival (P = 0.002), and the factor found on multivariate analysis to significantly affect overall survival was only pathologic stage (P = 0.040). Further stratified survival analysis split by pathologic stage demonstrated that MTA1 protein high expression significantly predicted unfavorable prognosis among patients with pathologic stage II disease (P = 0.006).

CONCLUSIONS

High expression of the MTA1 protein is common in ESCC, and is closely associated with tumor progression, increased tumor angiogenesis, and poor survival. These findings indicate that MTA1 protein has clinical potentials as a useful indicator of progressive phenotype, a promising prognostic predictor to identify patients with poor prognosis, and a potential novel therapeutic target of antiangiogenesis for patients with ESCC.

Overexpression of metastasis-associated protein 1 is significantly correlated with tumor angiogenesis and poor survival in patients with early-stage non-small cell lung cancer

BACKGROUND

The aims of this work are to detect the expression levels of metastasis-associated protein 1 (MTA1) in patients with early-stage non-small cell lung cancer (NSCLC), and to investigate the relationship of MTA1 protein with clinicopathologic factors, tumor angiogenesis, and prognosis.

METHODS

One hundred and two patients with pathologic stage I NSCLC who successfully underwent curative surgical resection were enrolled in this study. Immunohistochemical staining for MTA1 and CD34 was performed using the streptavidin-peroxidase method, and intratumoral microvessel density (MVD) was recorded by counting CD34-positive immunostained endothelial cells. All statistical analyses were performed with SPSS statistical software to determine the effects of MTA1 protein on clinicopathologic factors, tumor angiogenesis, and prognosis.

RESULTS

MTA1 protein overexpression was detected in 41 cases and was significantly associated with MVD (P = 0.008). MTA1 protein overexpression and high MVD were significantly associated with tumor relapse (P = 0.004 and 0.007) and poor 5-year disease-free survival (P = 0.001 and 0.004). Patients with MTA1 protein overexpression and high MVD had significantly poor overall survival (P = 0.005 and 0.043) and disease-specific survival (P = 0.006 and 0.031) at 5 years after operation. Multivariate analysis demonstrated that MTA1 protein overexpression was an independent prognosticator for unfavorable disease-free, overall, and disease-specific survival (P = 0.011, 0.024, and 0.046).

CONCLUSIONS

MTA1 protein overexpression is common in early-stage NSCLC and is significantly associated with tumor angiogenesis and poor survival. These findings suggest that MTA1 may have clinical potential as a promising predictor to identify individuals with poor prognostic potential and as a possible novel target molecule of antiangiogenic therapy for patients with early-stage NSCLC.

Mucin 1 and vascular endothelial growth factor C expression correlates with lymph node metastatic recurrence in patients with N0 esophageal cancer after Ivor-Lewis esophagectomy

BACKGROUND

The purpose of the present study was to investigate the risk factors associated with lymph node metastatic recurrence in patients with N0 esophageal cancer after Ivor-Lewis esophagectomy based on the detection of Mucin 1 mRNA and vascular endothelial growth factor (VEGF) C mRNA.

METHODS

The subjects were 82 patients with pN0 esophageal cancer who underwent Ivor-Lewis esophagectomy with two-field lymph node dissection from January 2001 to January 2005. A total of 501 lymph nodes obtained from these patients were re-evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR) to detect mucin l (MUC1) mRNA; VEGF-C mRNA was also detected in esophageal cancer issues by RT-PCR. The diagnosis of lymph node micrometastasis (LNMM) was based on the detection of MUC1 mRNA. The Kaplan-Meier method was used to calculate the survival rate and lymph nodal metastatic rate, the log-rank test was performed to compare the recurrence rate, and Cox regression multivariate analysis was performed to determine independent prognostic factors.

RESULTS

MUC1 mRNA was detected in 29 lymph nodes from 23 patients, which accounted for 5.79% of all the 501 lymph nodes and 28.05% of all 82 patients, respectively. Vascular endothelial growth factor C mRNA was identified in esophageal cancer issues from 42 (51.22%) patients. The overall 3- and 5-year survival rates of 82 patients were 78.0 and 51.2%, respectively. First recurrence exhibiting lymph nodal metastasis was recognized in 37 patients (45.1%) in the first 3 years after operation. The lymph node metastatic rate in patients in the first 3 years after operation was significantly associated with T status (p < 0.05) and the lymph node metastatic rate of the patients with LNMM was significantly higher than that of the patients without LNMM (p < 0.01). The lymph node metastatic rate of the patients with VEGF-C mRNA expression in esophageal cancer tissues was significantly higher than that of the patients without VEGF-C mRNA expression (p < 0.01).The results of multivariate analysis confirmed that VEGF-C mRNA expression in esophageal cancer tissues, LNMM, and T status in patients with N0 esophageal cancer were independent relevant factors for 3-year lymph node metastatic recurrence after Ivor-Lewis esophagectomy.

CONCLUSIONS

Vascular endothelial growth factor C mRNA expression in esophageal cancer tissues, LNMM, and T status in patients with N0 esophageal cancer were independent risk factors for 3-year lymph node metastatic recurrence after Ivor-Lewis esophagectomy. Adjunctive therapy might be beneficial in controlling the locoregional recurrence and elevated healing rates for certain patients.

ShRNA-mediated gene silencing of MTA1 influenced on protein expression of ER alpha, MMP-9, CyclinD1 and invasiveness, proliferation in breast cancer cell lines MDA-MB-231 and MCF-7 in vitro

BACKGROUND

MTA1(metastasis associated-1) is a tumor metastasis associated candidate gene and overexpression in many human tumors, including breast cancer. In this study, we investigated depressive effect on MTA1 by MTA1-specific short hairpin RNA(shRNA) expression plasmids in human breast cancer cell lines MDA-MB-231 and MCF-7, and effect on protein levels of ER alpha, MMP-9, cyclinD1, and tumor cell invasion, proliferation.

METHODS

ShRNA expression vectors targeting MTA1 was constructed and transfected into human breast cancer cell lines MDA-MB-231 and MCF-7. The transfection efficiency was evaluated by fluorescence microscopy, mRNA levels of MTA1 were detected by reverse transcription-polymerase chain reaction (RT-PCR), protein levels of ER alpha, MMP-9 and cyclinD1 were detected by Western blotting, respectively. Tumor cells invasive ability were evaluated by Boyden chamber assay, the cells proliferation were evaluated using cell growth curve and MTT analysis, the cell cycle analysis was performed using flow cytometry.

RESULTS

Down-regulation of MTA1 by RNAi approach led to re-expression of ER alpha in ER-negative breast cancer cell lines MDA-MB-231, and reduced protein levels of MMP-9 and CyclinD1, as well as decreased tumor cell invasion and proliferation, more cells were blocked in G0/G1 stage(P < 0.05). However, after inhibiting mRNA levels of MTA1, protein expression of ER alpha, MMP-9, cyclinD1 and the changes of cancer cells invasiveness, proliferation, cells cycle were no statistical difference in ER-positive human breast cancer cell lines MCF-7 (P > 0.05).

CONCLUSIONS

ShRNA targeted against MTA1 could specifically mediate the MTA1 gene silencing and consequentially recover the protein expression of ER alpha, resulting in increase sensitivity of antiestrogens, as well as suppress the protein levels of MMP-9 and cyclinD1 in ER-negative human breast cancer cell lines MDA-MB-231. Silencing effect of MTA1 could efficiently inhibit the invasion and proliferation in MDA-MB-231 cells. The shRNA interference targeted against MTA1 may have potential therapeutic utility in human breast cancer.

Involvement of HER-2/neu and metastasis-related proteins in the development of ileal neuroendocrine tumors

HER-2/neu overexpression and/or gene amplification occurs in several human malignancies, frequently correlates with tumor aggressiveness, and provides the basis for treatment with trastuzumab. Among neuroendocrine neoplasms (NEN) of the gastroenteropancreatic (GEP) tract, ileal neuroendocrine tumors show peculiar features of malignancy with frequent metastases at the diagnosis. We investigated the overexpression and/or amplification of HER-2/neu and the involvement of the metastasis-related proteins c-Met, MTA-1, and VEGF in 24 primary ileal NEN by immunohistochemistry and fluorescence in situ hybridization (FISH). Data were compared with those of 43 GEP endocrine tumors of other sites. All primary ileal NEN showed an intense membranous and cytoplasmic immunostaining for HER-2/neu. According to the breast cancer scoring system, 17% of ileal carcinoids showed a score of 3+ and 71% with a score of 2+ with a significant difference respect the non-ileal GEP endocrine tumors (p < 0.0000). FISH analysis revealed chromosome 17 polysomy in 33% of 2+/3+ ileal tumors but not HER-2/neu gene amplification. The c-Met and MTA-1 but not VEGF were overexpressed in almost all ileal NEN, whereas VEGF presented more frequently a normal staining. The comparisons with the other GEP NEN demonstrated significant differences for all the three proteins (p < 0.0000, p < 0.0002, and p < 0.001, respectively). These findings suggest that in ileal NEN, HER-2/neu overexpression plays a role in the carcinogenetic process and by triggering the altered expression of c-Met and MTA-1, may activate the molecular pathway(s) promoting tumor progression and metastasis development. Ileal HER-2/neu overexpressing neuroendrocrine tumors may constitute potential candidates for target therapy with specific humanized monoclonal antibodies.

Clinical study on lymph node metastatic recurrence in patients with N0 esophageal squamous cell cancer

Esophageal squamous cell cancer (ESCC) is one of the most common malignancies treated by thoracic surgeons. It is aggressive and generally associated with a poor prognosis. One of the most important prognostic factors is the presence of the lymph node metastasis (LNM). The purpose of the present study was to investigate the risk factor with lymph node metastatic recurrence in patients with N0 esophageal squamous cancer after Ivor Lewis esophagectomy based on the detection of mucin1 (MUC1) mRNA. The subjects were 82 patients with pN0 ESCC who underwent Ivor Lewis esophagectomy with two-field lymph node dissection from January 2001 to January 2005. All lymph nodes (501 stations) obtained from these patients were reevaluated by reverse transcriptase-polymerase chain reaction (RT-PCR) to detect MUC1mRNA. The diagnosis of lymph node micrometastasis (LNMM) was based on the detection of MUC1 mRNA. The Kaplan-Meier method was used to calculate the survival rate and lymph nodal metastatic rate. Log-rank test was performed to compare the recurrence rate, and Cox regression multivariate analysis was performed to determine independent prognostic factors. The overall 3-year survival rates of 82 patients were 78.0%, and the first recurrence exhibiting lymph nodal metastasis was recognized in 37 patients (45.1%) in the first 3 years after operation. Lymph node metastatic rate in patients in the first 3 years after operation was significantly associated with the T status (P < 0.05). MUC1 mRNA was identified in at least one lymph node station from 23 (28.1%) patients. Also, lymph node metastatic rate of the patients with LNMM was significantly higher than that of the patients without LNMM (P < 0.01).The results of multivariate analysis confirmed that LNMM and T status in patients with N0 ESCC were independent risk factors for 3-year lymph node metastatic recurrence after Ivor Lewis esophagectomy. Adjunctive therapy might be beneficial in controlling the locoregional recurrence and elevated healing rates for certain patients.