The expression of CXCR4 and its relationship with matrix metalloproteinase‐9/vascular endothelial growth factor in esophageal squamous cell cancer

Esophageal cancer (EC) is a highly aggressive neoplasm with poor prognosis. The main reason for this disappointing outcome is the strong behavior of esophageal cancer cell's invasion and metastasis. CXC chemokine receptor 4 (CXCR4) was found to be expressed in many tumors and significantly correlated with invasion, angiogenesis, metastasis, and prognosis. In the present study, we investigated the expressions of CXCR4, matrix metalloproteinase‐9 (MMP‐9), and vascular endothelial growth factor (VEGF) in esophageal squamous cell cancer (ESCC) and analyzed the relationship among the three proteins. Sections of paraffin‐embedded tissues were obtained from 127 patients with ESCC undergoing esophagectomy at Zhongshan Hospital, Fudan University in 2005. The CXCR4, MMP‐9, and VEGF expressions in EC tissues were evaluated according to the immunohistochemical staining area and intensity. The correlations between patients' prognosis and covariates were analyzed by Kaplan–Meier method (univariate analysis) and Cox regression (multivariate analysis). The overall expression rate of CXCR4, MMP‐9, and VEGF was 88.2%, 93.7%, and 79.5%, respectively. CXCR4 expression was significantly associated with tumor grade, tumor size, tumor depth, regional lymph node metastasis, and tumor, node, metastasis (TNM) stage (P < 0.05). MMP‐9 expression was significantly associated with age and tumor grade (P < 0.05). VEGF expression was significantly associated with tumor grade, tumor depth, and TNM stage (P < 0.05). CXCR4 expression was positively correlated with MMP‐9 expression (P < 0.01, r= 0.365) and VEGF expression (P < 0.01, r= 0.380). However, there was no significant correlation between MMP‐9 and VEGF expression (P > 0.05). In univariate analysis, CXCR4 expression, tumor size, tumor depth, lymph node metastasis, and TNM stage were correlated with patients' prognosis (P < 0.05); in multivariate analysis, tumor size and lymph node metastasis were the independent factors of poor prognosis. CXCR4 was highly expressed in ESCC and correlated with MMP‐9, VEGF, clinicopathological features and prognosis. We speculated CXCR4 play an important role during the progression of this disease and there might be some regulatory mechanism existing between CXCR4 and MMP‐9/VEGF in ESCC.     

Overexpression of EphA2, MMP‐9, and MVD‐CD34 in hepatocellular carcinoma: Implications for tumor progression and prognosis

Aim: To investigate the expression of erythropoietin‐producing hepatocellular (Eph)A2 receptor, matrix metalloproteinase (MMP)‐9, and angiogenesis in hepatocellular carcinoma (HCC), in order to reveal their expression correlations with tumor invasion, metastasis, and prognosis. Methods: From January 2000 to June 2003, 129 specimens of resected tumors from the patients with HCC were obtained. Corresponding pericarcinomatous liver tissues were also obtained and selected as a control group. Expressions of EphA2, MMP‐9, and CD34 were detected with immunohistochemical staining. Microvascular density (MVD) was calculated with counting of CD34‐positive vascular endothelial cells. Results: The expressions of EphA2, MMP‐9, and MVD in the HCC tissues were significantly higher than those in the pericarcinomatous liver tissues (P < 0.01). Statistical analysis showed there were significant correlations between the expressions of EphA2, MMP‐9 and MVD in some classicclinicopathological parameters (i.e. tumor nodule, vein invasion, tumor, node, metastasis stages, extrahepatic metastasis; P < 0.05). The correlation between EphA2 and MMP‐9 expression was positive (r = 0.625, P = 0.011). Tumor MVD was closely associated with EphA2 (r = 0.281, P = 0.01) and MMP‐9 (r = 0.319, P < 0.01) expressions. In particular, EphA2, MMP‐9, and MVD expressions levels were found to be independent prognostic factors after HCC resection. Conclusions: Overexpressions of EphA2 and MMP‐9 relate to tumor progression, metastasis, and prognosis in HCC. The present study suggests that EphA2 is associated with key mediators of angiogenesis and invasion.     

基质金属蛋白酶-9和组织金属蛋白酶抑制剂-1在食管鳞癌中的表达

目的探讨基质金属蛋白酶-9（MMP-9）和组织金属蛋白酶抑制剂-1（TIMP-1）在食管鳞癌中的表达及其临床意义。方法用免疫组化和Western blot法分别检测41例食管鳞癌患者的癌及相应正常组织中MMP-9和TIMP-1的表达变化。结果食管鳞癌组织中MMP-9阳性表达率与食管癌淋巴结及静脉转移有关；MMP-9的阳性表达率与表达量均显著高于TIMP-1；MMP-9和TIMP-1的表达呈负相关。结论MMP-9与食管鳞癌的侵袭转移有关，其机制可能与食管鳞癌组织中的MMP-9／TIMP-1平衡失调有关；MMP-9与TIMP-1联合检测有助于食管鳞癌生物学行为的判断。     

Matrix metalloproteinases expression correlates with survival in patients with esophageal squamous cell carcinoma

OBJECTIVES: The matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases capable of degrading the extracellular matrix and play important roles in malignancies. We evaluated the expression of four MMPs in esophageal squamous cell carcinoma (ESCC), and assessed the association between MMP expression and clinicopathologic characteristics and disease-free survival time. METHODS: We evaluated MMP1, MMP7, MMP9, and MMP13 expression in tissues from 208 patients with ESCC using immunohistochemistry (IHC), and correlated MMP expression to clinicopathologic characteristics and disease-free survival time. To confirm MMP9 expression at different levels, we simultaneously performed RT-PCR, Western blotting, and IHC on tissues from a separate cohort of 23 patients with ESCC. RESULTS: IHC analysis showed that 63.0%, 41.8%, 49.0%, and 32.2% of 208 ESCC samples were positive for MMP1, MMP7, MMP9, and MMP13, respectively. MMPs were strongly expressed in the cytoplasm of cancer cells, especially in the invasive margin, and weakly expressed in stromal cells. No immunostaining was detected in non-cancerous esophageal mucosa. MMP9 expression was positively associated with poor tumor cell differentiation (p= 0.001), vessel permeation (p= 0.027), and lymph node metastasis (p= 0.027). MMP9 expression was a negative, independent predictor of disease-free survival time (Hazard ratio, 1.470; 95% CI, 1.105 approximately 1.955; p= 0.008). The expression of MMP7 (median survival time: 23 months for MMP7 positive patients, >77 months for MMP7 negative patients; p= 0.001) and MMP13 (median survival time: 18 months for MMP13 positive patients, 39 months for MMP13 negative patients; p= 0.014) correlated negatively with disease-free survival in relatively early stage ESCC patients. Co-expression of MMP7, MMP9, and MMP13 in relatively early stage ESCC samples identified patients with a poor prognosis (13 months median survival time) compared to those lacking MMP7, MMP9, and MMP13 expression (58 months median survival time, p < 0.001). CONCLUSIONS: MMP9 expression is a negative, independent prognostic factor in ESCC and correlates with tumor cell differentiation, vessel permeation, and lymph node metastasis. MMP7, MMP9, and MMP13 may function in early stage ESCC, and their co-expression predicts poor outcome for relatively early stage ESCC patients.     

Clinical effect of E‐series of prostaglandin receptor 2 and epidermal growth factor receptor signal pathways in the development of esophageal squamous cell carcinoma

Signal pathways mediated by epidermal growth factor receptor (EGFR) and E‐series of prostaglandin receptors (EPs) are closely correlated to the pathogenesis of tumor. This experiment was designed to investigate the expression and clinical significance of EP2 and EGFR in esophageal squamous cell carcinoma (ESCC). Tissue samples were collected reterospectively from 87 patients with ESCC (first diagnosed). The patients were followed up for 5 years after radical surgery. The expression of EP‐2 and EGFR were examined by tissue chip technology and immunohistochemistry methods. Clinicopathological and prognostic impact were evaluated. Overexpression of EGFR and EP‐2 was more observed in ESCC than the control group (58.6% vs. 13.9%; 52.9% vs. 4.88%, P < 0.001, respectively); which correlated with tumor infiltration depth, lymph node metastasis, and tumor‐lymph node‐metastasis staging. Both the EP‐2 and EGFR overexpression were detected in 39 specimens and exhibited the positive correlation (P < 0.001, r = 0.404). Overexpression of EP2 and EGFR exhibited significant correlation with worse 5‐year overall survival than those with negative result (17.6% vs. 27.8%, P = 0.011; 10.9% vs. 34.1%, P < 0.001, respectively). Cox proportional hazard model showed that the T‐staging, lymph node metastasis, and EGFR overexpression were the independent risk factors of the prognosis. The present study exhibited that the overexpression of EP2 and EGFR in ESCC tissues might play an important role in carcinogenesis and the progression of ESCC.     

Original article: The expression of CFL1 and N‐WASP in esophageal squamous cell carcinoma and its correlation with clinicopathological features

Cofilin1 (CFL1) is an actin‐modulating protein, which belongs to the ADF/Cofilin family. Neural Wiskott–Aldrich syndrome protein (N‐WASP) is the key regulator of the actin cytoskeleton, a member of Wiskott‐Aldrich syndrome protein family. They have been suggested to be involved in cancer cell invasion and metastasis. In this study, the expression patterns of CFL1 and N‐WASP in normal esophageal mucosa and esophageal squamous cell carcinoma (ESCC) and their correlation with clinical characteristics were investigated. Immunohistochemical staining showed that CFL1 was expressed in nuclear and cytoplasm of cancer cells. However, N‐WASP was mainly found in the cytoplasm of the cancer cells. There were significant evidences that proved that CFL1 is correlated with clinicopathological factors in ESCC, such as infiltration depth, lymph node metastasis and pathological staging (P < 0.05). It is also proved that N‐WASP is related to lymph node metastasis and pathological staging in ESCC (P < 0.05). Kaplan–Meier analysis showed that there was no correlation between CFL1 and N‐WASP protein expression and survival (P > 0.05). Moreover, the mRNA expression of CFL1 and N‐WASP was detected by quantitative real time PCR in 70 tissue specimens. The results showed that CFL1 mRNA level was over‐expressed in ESCC tissue (P < 0.05), while N‐WASP mRNA expression level was not different between cancerous tissues and adjacent normal esophageal mucosa (P > 0.05). Also, CFL1 mRNA expression was significantly associated with regional lymph node metastasis and pathological staging (P < 0.05). Kaplan–Meier analysis showed that there was no correlation between CFL1 and N‐WASP mRNA expression and survival (P > 0.05). Our findings suggested that CFL1 and N‐WASP may play an important role in the tumorigenesis of ESCC, and to be the candidate novel biomarkers for the diagnosis and prognosis of ESCC. These findings may have implications for targeted therapies in patients with ESCC.     

Clinical Impact of HAb18G/CD147 Expression in Esophageal Squamous Cell Carcinoma

Background

HAb18G/CD147 expression has been associated with many tumor invasion molecules, which play important roles in recurrence and poor differentiation of esophageal squamous cell carcinoma (ESCC). However, the clinical implications of HAb18G/CD147 in ESCC are still unclear.

Aims

In this study, we clarified the clinical significance of HAb18G/CD147 and characterized the association between HAb18G/CD147 and tumor invasion in ESCC cases.

Methods

Tumor tissues were obtained from 86 ESCC patients who underwent surgical resection between 2002 and 2005. All patients that had received previous therapy were excluded. ESCC tissues were analyzed by IHC using anti HAb18G/CD147 antibody. The expression of HAb18G/CD147 mRNA in esophageal cancer cell lines was analyzed by RT?CPCR.

Results

HAb18G/CD147 was uniformly expressed in EC109 and EC871214 cell lines, but negatively expressed in EPC2, esophageal normal squamous cell line. HAb18G/CD147 mainly localized to the membrane of tumor cells in 84.9% of ESCC patients (64 out of 86 cases). Furthermore, we also found that higher HAb18G/CD147 expression levels significantly correlated with lymph node metastasis, depth of tumor invasion and differentiation (P < 0.05). But the expression levels of HAb18G/CD147 in lymph node metastatic tissues were almost equal to that in the primary tumor tissues. Furthermore, lymph node metastasis and expression of HAB18G/CD147 were independent prognostic indicators in ESCC.

Conclusions

The expression of HAb18G/CD147 might be involved in the progression and survival of ESCC. Therefore, HAb18G/CD147 could be a clinical marker for the poor prognosis in ESCC patients and may also be a potentially therapeutic target to improve the progression of ESCC.     

BMP7 Expression in Esophageal Squamous Cell Carcinoma and Its Potential Role in Modulating Metastasis

Background

Our previous study showed that BMP7 revealed significantly higher levels in esophageal squamous cell carcinoma (ESCC) tissues with lymph node metastasis compared with non-lymph node metastasis, using gene expression profiling assays. The roles of BMP7 in ESCC is not fully understood.

Aim

The aim of this study was to investigate the effect of BMP7 on lymph node metastasis of ESCC and to explore its potential mechanism.

Methods

Expression of BMP7 in ESCC tissues was evaluated by immunohistochemistry. BMP7 were down-regulated by RNA interference. The protein and mRNA levels of BMP7 were detected by western blot and RT-PCR, respectively. High content screening and transwell assay were used to identify the metastatic ability of tumor cells.

Results

Positivity of BMP7 staining was 57.5 % in the tissues of primary carcinoma with lymph node metastasis compared to tissues without lymph node metastasis, and expression of BMP7 was significantly higher in the cell lines with highly metastatic capacity than that in the cell lines without metastatic ability. Suppression of endogenous BMP7 expression by siRNA in the highly metastatic cell lines resulted in significant reduction in ability of cell migration and invasion in both in vitro and in vivo studies. In addition, inhibition of BMP7 by siRNA also leads to up-regulation of E-cadherin and down-regulation of MMP-9 in the highly metastatic cell lines.

Conclusions

These findings indicate that BMP7 modulates the expression of E-cadherin and MMP-9, and by which mechanism it may regulate cell migration and metastasis of ESCCs.     

Common single nucleotide polymorphism of hypoxia‐inducible factor‐1α and its impact on the clinicopathological features of esophageal squamous cell carcinoma

OBJECTIVE: Angiogenesis is one of the most important molecular events in solid tumor development and growth, in which hypoxia‐inducible factor (HIF)‐1α is a key regulator and plays an important role. Studies have shown that a single nucleotide polymorphism (C1772T) in the HIF‐1α gene exerts a large effect on the phenotype of human head and neck squamous cell carcinoma and renal cell carcinoma. But the impact of the C1772T polymorphism on the clinicopathological features of human esophageal squamous cell carcinoma (ESCC) remains unknown, and thus it is the main focus of our study. METHODS: The C1772T genotype of 95 ESCC patients and 104 healthy controls were studied by using the polymerase chain reaction and restriction fragment length polymorphism. Mutations were confirmed by direct DNA sequencing. The impact of C1772T on tumor size, invasive depth, lymph node metastasis, distant metastasis, histological grade and TNM stage was also studied. RESULTS: The genotype frequency observed in the patients and controls was 11.58% versus 10.58%, respectively, for genotype C/T (P > 0.05). Genotype T/T was not found in our study. Larger tumors and a higher rate of lymph node metastasis was found for the C/T group. CONCLUSIONS: Although there is no significant difference of genotype distribution between ESCC patients and healthy controls, genotype C/T is associated with larger tumor and higher rate of lymph node metastasis.     

Overexpression of matrix metalloproteinase 10 is associated with poor survival in patients with early stage of esophageal squamous cell carcinoma

Matrix metallopeptidase 10 (MMP10) is frequently expressed and correlates closely with metastasis and poor prognosis in various human cancers. However, the significance of MMP10 expression in esophageal squamous cell carcinoma (ESCC) and its role in ESCC progression remains unclear. In this report, upregulation of MMP10 mRNA was detected in 39/60 (65.0%) of primary ESCC tissues compared with their paired nontumor esophageal tissues. Tissue microarray (TMA) study found protein overexpression of MMP10 in 188/239 (78.7%) of primary ESCC tissues but not in their corresponding nontumor esophageal tissues, suggesting that overexpression of MMP10 may play important roles in ESCC development and progression. Although the overexpression of MMP10 was not significantly associated with disease-specific survival rate (P= 0.182) for all tested ESCCs, it was significantly associated with poorer disease-specific survival (P= 0.001) in early stage of ESCCs (I-IIA). In addition, multivariate analysis found that MMP10 expression in tumor tissues was evaluated as a potential independent prognostic factor for early stage ESCC patients. These findings suggest that MMP10 plays an important role in ESCC progression in the early stage, and overexpression of MMP10 in tumor tissues could be used as a potential prognostic marker for patients with early clinical stage of ESCC.     

Functional studies of a novel oncogene TGM3 in human esophageal squamous cell carcinoma

AIM: To investigate the role of transglutaminase 3 (TGM3) gene in human esophageal squamous cell carcinoma (ESCC), and analyze its relationship with clinicopathological parameters. METHODS: Gene expression of TGM3 in fresh esophageal cancer tissues and their corresponding normal mucosas was detected immunohistochemically(IHC) by means of tissue microarray(TMA). Its correlation with clinical characteristics was evaluated and analyzed by univariate analysis. All statistical analyses were performed by SPSS version 10.0. RESULTS: Expression rate of TGM3 was reduced to 81.8% in ESCC. Expression of TGM3 was significantly inversely correlated with histological grade of esophageal carcinoma (in gradeⅠ,ⅡandⅢtumors, the reduced expression was 4/7,57/71, and 20/21, respectively, P < 0.05), whereas it had no obvious correlations with lymph node metastasis and depth of invasion. CONCLUSION: Reduced expression of TGM3 may play an important role in esophageal carcinogenesis.     

Melatonin inhibits matrix metalloproteinase‐9 activity by binding to its active site

The zinc‐dependent matrix metalloproteinases (MMPs) are key enzymes associated with extracellular matrix (ECM) remodeling; they play critical roles under both physiological and pathological conditions. MMP‐9 activity is linked to many pathological processes, including rheumatoid arthritis, atherosclerosis, gastric ulcer, tumor growth, and cancer metastasis. Specific inhibition of MMP‐9 activity may be a promising target for therapy for diseases characterized by dysregulated ECM turnover. Potent MMP‐9 inhibitors including an indole scaffold were recently reported in an X‐ray crystallographic study. Herein, we addressed whether melatonin, a secretory product of pineal gland, has an inhibitory effect on MMP‐9 function. Gelatin zymographic analysis showed a significant reduction in pro‐ and active MMP‐9 activity in vitro in a dose‐ and time‐dependent manner. In addition, a human gastric adenocarcinoma cell line (AGS) exhibited a reduced (~50%) MMP‐9 expression when incubated with melatonin, supporting an inhibitory effect of melatonin on MMP‐9. Atomic‐level interaction between melatonin and MMP‐9 was probed with computational chemistry tools. Melatonin docked into the active site cleft of MMP‐9 and interacted with key catalytic site residues including the three histidines that form the coordination complex with the catalytic zinc as well as proline 421 and alanine 191. We hypothesize that under physiological conditions, tight binding of melatonin in the active site might be involved in reducing the catalytic activity of MMP‐9. This finding could provide a novel approach to physical docking of biomolecules to the catalytic site of MMPs, which inhibits this protease, to arrest MMP‐9‐mediated inflammatory signals.     

MMP‐9 and TIMP‐1 in the cord blood of premature infants developing BPD

We investigated matrix metalloproteinase‐9 (MMP‐9) and tissue inhibitor of metalloproteinase 1 (TIMP‐1) levels in the cord blood of 29 premature infants who were <30 weeks gestation. One, 8, and 14 infants developed severe, moderate and mild bronchopulmonary dysplasia (BPD), respectively, and 6 did not. MMP‐9 and TIMP‐1 levels in the cord blood were determined by ELISA. MMP‐9/TIMP‐1 ratios in the cord blood of infants who developed severe or moderate BPD (n = 9) were significantly higher than those who developed mild BPD or did not develop BPD (n = 20; P = 0.015). Multivariate linear regressions demonstrated that MMP‐9 levels and MMP‐9/TIMP‐1 ratios in the cord blood of the premature infants correlated with the oxygen supplementation period (r = 0.58, P = 0.003 and r = 0.41, P = 0.030, respectively). The MMP‐9 levels and MMP‐9/TIMP‐1 ratios correlated with the severity of maternal chorioamnionitis (both trend P = 0.006). The MMP‐9 levels and MMP‐9/TIMP‐1 ratios in the cord blood may be related to the pathogenesis and severity of BPD and maternal chorioamnionitis. Pediatr Pulmonol. 2009; 44:267–272. © 2009 Wiley‐Liss, Inc.     

Overexpression of Ets-like protein 1 in human esophageal squamous cell carcinoma

INTRODUCTION Esophageal cancer ranks among the 10 most frequent cancers in the world, with a predominant distribution in developing countries. It is one of the most common malignant tumors in China[1,2]. Our previous study showed that genetic susceptibili…     

Association between positive murine double minute 2 expression and clinicopathological characteristics of esophageal squamous cell carcinoma: a meta‐analysis

The correlations of murine double minute 2 (MDM2) T309G and esophageal cancer were elucidated because the association between MDM2 expression states and clinicopathological parameters of esophageal squamous cell carcinoma (ESCC) is controversial. We conducted a meta‐analysis on studies screened from PubMed, Web of Science, Embase, the Cochrane Library, and the Chinese Biomedical Literature Databases that were published before October 2014. All studies describing the association between MDM2 and ESCC were traced. Meta‐analysis was performed using the STATA software (Stata Corp., College Station, TX, USA). A total of 9 studies with 707 cases and 324 controls were included. MDM2 expression was higher in ESCC than in normal esophageal epithelium (odds ratio [OR] 10.38, 95% confidence interval [CI] 6.42–16.78, P < 0.001). High MDM2 expression was associated with early primary tumor stage (T1/T2 vs. T3/T4, OR 0.59, 95% CI 0.38–0.92, P = 0.018) and increased risk of regional lymph node metastasis (N0 vs. N1, OR 1.66, 95% CI 1.03–2.67, P = 0.039). However, no relationship was observed between MDM2 expression and the risk of distant metastasis (OR = 2.09, 95% CI 1.00–4.36, P = 0.050), and MDM2 was not significantly correlated with TP53 expression (OR 1.22, 95% CI 0.53–2.77, P = 0.643). Our analysis suggests that MDM2 acts as a potent marker of early primary tumor stage but higher risk of regional lymph node metastasis in ESCC. However, because of the limited number of studies included, the result should be further clarified by well‐designed prospective studies.     

肌动蛋白凝胶蛋白在食管鳞癌中的表达及其与临床病理因素的关系

目的探讨肌动蛋白凝胶蛋白(Transgelin)在食管鳞癌组织中的表达及其与临床病理因素间的关系。方法采用免疫组化法检测Transgelin在食管鳞癌组织、癌旁不典型增生组织及正常食管黏膜组织中的表达,并分析Transgelin的表达与患者临床病理因素特征的关系及其对预后的影响。结果Transgelin在食管鳞癌中的阳性率明显高于癌旁不典型增生组和正常食管黏膜组织,其差异有统计学意义(P<0.05)。Transgelin在食管癌中的表达与患者的的TNM分期(P<0.05)、淋巴结转移(P<0.05)、远处转移(P<0.05)有关;与患者的性别、年龄、肿瘤直径无关(P>0.05)。在随访的210例患者中,Transgelin的生存曲线显示,高表达组Transgelin的5年生存率明显低于低表达组(P<0.05)。单因素生存分析显示,Transgelin的表达水平、TNM分期、淋巴结转移、远处转移与食管鳞癌患者术后生存时间相关。同时,多因素Cox比例风险回归模型分析显示,Transgelin的表达水平、TNM分期、淋巴结转移和远处转移为食管鳞癌患者预后的独立危险因素。结论Transgelin在食管鳞癌组织中呈高表达,其表达与食管鳞癌的发生发展和侵袭转移相关,Transgelin对于术后食管鳞癌患者的预后评估具有参考价值。     

Clinicopathological significance of cyclooxygenase‐2 and cell cycle‐regulatory proteins expression in patients with esophageal squamous cell carcinoma

The aim of this study was to examine the expression of the molecular markers cyclooxygenase‐2 (COX‐2), Ki‐67, cyclin A, and p27 in patients with esophageal squamous cell carcinoma (ESCC), to ascertain the relationship of these makers with the clinicopathological significance of the patients, and to assess the additional prognostic value of the expression profile of these proteins for ESCC patients. The expression levels of COX‐2, Ki‐67, cyclin A, and p27 proteins of a series of primarily resected ESCC samples were determined by immunohistochemistry method. Clinicopathological and molecular factors affecting survival were analyzed by multivariate analysis. A total of 78 specimens were included in this study. Expression of COX‐2 was observed in 43 (55.1%) cases, and high levels of expression of Ki‐67, p27, and cyclin A were observed in 57 (73.0%), 33 (42.3%), 43 (55.1%) cases, respectively. The results of univariate survival analysis indicated that more advanced tumor stage, lymph node involvement, systemic dissemination, the levels of expression of COX‐2, Ki‐67, cyclin A, and p27 were associated with survival (all P‐value < 0.05). Multifactorial survival analysis revealed that only lymph node involvement, over‐expression of cyclin A, and low p27 expression were associated with the survival of the patients (hazard ratios = 2.83, 4.7, 2.9, respectively; P= 0.025, 0.042, 0.005, respectively). Among the molecular markers assessed, the expression of cell proliferation markers cyclin A and p27 are independent prognostic factors in patients with ESCC, whereas neither COX‐2 nor Ki‐67 is of independent prognostic value.     

Expression of FOXP3 in esophageal squamous cell carcinoma relating to the clinical data

Forkhead box protein 3 (FOXP3) has been studyed as a biomarker in many human malignancies recently. But in esophageal squamous cell carcinoma (ESCC) the studies are limited. In this study, expression of FOXP3 in ESCC tissue was evaluated in relation to the clinical data. Detection of FOXP3 mRNA was made by using quantitative real‐time PCR while protein expression was assessed by immunocytochemistry (n = 112). The results were correlated to the clinical data including age, gender, carcinoma size, carcinoma differentiation, lymphatic invasion and pathological stage. A significantly higher FOXP3 expression in tumors was confirmed than in normal‐appearing mucosa. The FOXP3 mRNA and protein expressions were higher in advanced stages (stage II B and III) than in early stages (stage I and stage II A). A significantly higher FOXP3 expression in tumors with lymph node metastasis was also confirmed than in those without lymph node metastasis. No significant correlation was found in age, gender, carcinoma size, or carcinoma differentiation. These results suggest that expression of FOXP3 was higher in ESCC tissue and was closely correlated to lymphatic invasion and pathological stage. It may imply that FOXP3 might play an important role in esophageal carcinoma progression.     

Down-Regulation of PTEN Expression Modulated by Dysregulated miR-21 Contributes to the Progression of Esophageal Cancer

Background and Aim

miR-21, a putative tumor oncomiR, is a frequently overexpressed miRNA in a variety of tumors. Because it targets tumor-suppressor genes it has been linked to tumor progression. In this study we investigated the role of miR-21 in esophageal squamous cell carcinoma (ESCC), and its possible mechanism.

Methods

Expression of miR-21 was detected by stem–loop RT-PCR in tissue from 76 invasive ESCC at stage I–IV and in their corresponding para-cancerous histological normal tissues (PCHNT). Thirty endoscopic esophageal mucosal biopsy specimens from non-tumor patients were used as controls. Expression of PTEN in 76 paired ESCC and PCHNT was investigated by real-time RT-PCR and an immunohistochemical method, respectively. Paired tumor and PCHNT specimens of 20 ESCC cases were randomly selected for western blot analysis. The effect of miR-21 on PTEN expression was assessed in the ESCC cell line with an miR-21 inhibitor to reduce miR-21 expression. Furthermore, the roles of miR-21 in cell biology were analyzed by use of miR-21 inhibitor-transfected cells.

Results

Stem–loop RT-PCR revealed miR-21 was significantly overexpressed in ESCC tissues and cell lines. Overexpression of miR-21 correlated with tumor status, lymph node metastasis, and clinical stage. We demonstrated that knockdown of miR-21 significantly increased expression of PTEN protein. Consequent PTEN expression reduced cell proliferation, invasion, and migration.

Conclusions

Our findings suggest that miR-21 could be a potential oncomiR, probably by regulation of PTEN, and a novel prognostic factor for ESCC patients.