Smad4/Smad7 balance: A role of tumorigenesis in gastric cancer

Smad signaling pathway plays an important role in tumorigenesis and progression in cancer (Halder, S.K., Rachakonda, G., Deane, N.G., Datta, P.K., 2008. Smad7 induces hepatic metastasis in colorectal cancer. Br. J. Cancer 99, 957-965). The protein level of Smad is associated with growth, inhibition, and metastasis in different cancers. It is unclear if the differentiation, metastasis and apoptosis are reduced by Smad expression pattern in gastric cancer. To determine the effect of Smad on gastric cancer cells, we investigated the relationship of Smad4/Smad7 expression, and differentiation, metastasis, and apoptosis in different gastric cancer. The results show that Smad4 expression in the gastric cancer tissue was dramatically lower than that in the peritumoral tissue. A lower expression of Samd4 was significantly lower in the poorly differentiated tissue than that in the well and middle differentiated tissues (P < 0.01). In contrast, Smad7 expression in gastric cancer tissues was significantly higher than that in the peritumoral tissue. Smad7 was overexpressed in poorly differentiated tissue, also higher than those in the middle, and well differentiated tissues (P < 0.05). The Smad4 or Smad7 expression obviously related with the lymphatic metastasis in gastric cancer. There were 45 cases with lymphatic metastasis in all 78 patients. Smad4 expression in the cases with lymphatic metastasis was lower than the cases without metastasis (P < 0.01), whereas Smad7 expression in the cases with lymphatic metastasis was much higher than the case without metastasis (P < 0.01). To better understand the mechanisms involved in tumorigenesis of gastric cancer, we established SGC7901 gastric cancer cell lines transduced with Smad4 or Smad7 plasmid DNA. Apoptosis and survival of cancer cells was induced after Smad4 and Smad7 transduction. This effect is concentration and time dependent. Thus, this study provides a mechanism by which a balance between Smad4 and Smad7 in human gastric cancer is critical for differentiation, metastasis, and apoptosis of tumor cells.     

High RSF-1 expression correlates with poor prognosis in patients with gastric adenocarcinoma

Aim

To investigate the expression and prognostic significance of RSF-1 in gastric adenocarcinoma.

Methods

RSF-1 expression was analyzed using immunohistochemical staining on tissue samples from a consecutive series of 287 gastric adenocarcinoma patients who underwent tumor resections between 2003 and 2006.The relationship between RSF-1 expression, clinicopathological factors, and patient survival was investigated.

Results

Immunohistochemical staining indicated that RSF-1 is highly expressed in 52.6% of gastric adenocarcinomas. RSF-1 expression levels were closely associated with tumor size, histological differentiation, tumor stage, and lymph node involvement. Kaplan-Meier survival analysis showed that high RSF-1 expression exhibited a significant correlation with poor prognosis for gastric adenocarcinoma patients. Multivariate analysis revealed that RSF-1 expression is an independent prognostic parameter for the overall survival rate of gastric adenocarcinoma patients.

Conclusion

Our data suggest that RSF-1 plays an important role in gastric adenocarcinoma progression and that high RSF-1 expression predicts an unfavorable prognosis in gastric adenocarcinoma patients.     

Decreased expression of histone deacetylase 10 predicts poor prognosis of gastric cancer patients

Aberrant expression of histone deacetylase (HDACs) was associated with carcinogenesis and progression of various tumors. However, the association of HDAC10 with clinical outcomes in gastric cancer patients is unclear. Thus, the objective of the current study was to evaluate the association of expression level of HDAC10 with clinicopathologic factors and prognosis of patients with gastric cancer. The expression level of HDAC10 in 179 paraffin-embedded gastric cancer tissue specimens was examined by immunohistochemistry (IHC). As a result, we found that expression of HDAC10 in gastric cancer was significantly decreased in gastric cancer tissues as compared with adjacent tissues (51.4% vs. 87.3%, P < 0.001). HDAC10 expression was significantly correlated with gender (P = 0.023), tumor size (P = 0.015), histological grade (P = 0.009), tumor invasion (P = 0.033), lymph node metastatic status (P = 0.019) and tumor stage (P = 0.004), but not correlated with age and lauren classification (all P > 0.05). Kaplan-Meier survival curves showed that the overall survival rate was significantly lower in the patients with low expression of HDAC10 compared with those patients with high HDAC10 (P < 0.001). Moreover, multivariate analysis revealed that HDAC10 expression was an independent prognostic factor for gastric cancer patients (P = 0.001). These results suggest that HDAC10 expression could see as a prognosis marker for gastric cancer patients.     

Fascin expression is related to poor survival in gastric cancer

Fascin is an actin‐binding protein that provides mechanical support and cell motility, and involves cancer cell metastasis. We investigated fascin protein expression in gastric cancer and assessed their relationship with clinicopathologic parameters and survival rates. In addition, we researched galectin‐3 protein expression to study fascin action mechanisms. We performed immunohistochemisty with fascin and galectin‐3 antibodies in 471 gastric carcinomas, using tissue microarrays. Fascin was positive in 14.9% (70/471) of the samples, and fascin expression was related to worse survival rates (P < 0.001), high clinical stage (P < 0.001), high T stage (P < 0.001), nodal metastasis (P < 0.001), lymphovascular invasion (P= 0.001) and the intestinal type of Lauren classification (P= 0.015). Galectin‐3 protein expression was positive in 83.9% (395/471) of the samples and was reversely correlated with fascin protein expression (P= 0.020). Galectin‐3 expression was related to low clinical stage (P < 0.001), but not to survival rates in multivariate analysis. In multivariate analysis, fascin expression was related to worse survival rates (HR = 1.56, P= 0.036), and can be an independent poor prognostic factor in gastric cancer.     

SLP-2在胃癌组织中的表达及其预后意义

 目的：探讨红细胞膜整合蛋白SLP-2（stomatin-like protein 2）在胃癌中的表达及其与临床病理学指标及预后的关系。方法：选取中山大学肿瘤防治中心病理科有完整临床资料的胃癌手术标本190例,应用免疫组织化学方法检测胃癌中SLP-2蛋白的表达,并分析其与临床病理特征及预后的关系。结果：（1）胃癌组织中SLP-2蛋白表达的阳性率为63.2%（120/190）。SLP-2表达与胃癌浸润深度、TNM分期及淋巴结转移有关（P<0.05）,而与患者性别、年龄、肿瘤分化程度、肿瘤直径和远处转移均无关（P>0.05）;（2）Kaplan-Meier 生存曲线分析结果显示：SLP-2阳性表达患者的累积生存率明显低于阴性表达患者（P<0.01）;（3）单因素分析结果显示：SLP-2 的表达、淋巴结转移、肿瘤分化程度、肿瘤直径、TNM分期、浸润深度及远处转移均影响胃癌预后;多因素分析表明,只有肿瘤直径和TNM分期是独立的预后指标。结论：（1）SLP-2在胃腺癌组织中高表达,可能参与胃腺癌的发生发展和转移;（2）SLP-2在一定程度上影响胃癌的预后,其过度表达提示胃癌预后差。     

Expression of p53 protein as a prognostic indicator of reduced survival time in diffuse-type gastric carcinoma

To determine whether p53 expression is different in intestinal and diffuse types of gastric carcinoma, we investigated p53 immunohistochemical expression in 178 primary gastric carcinomas. Overexpression of p53 was observed in 50 out of 100 intestinal-type tumors (50.0%) and in 27 out of 78 diffuse-type tumors (34.6%). A significant difference was found in the timing of p53 overexpression between the two types of carcinomas. Overexpression of p53 occurred often in the early stage of intestinal-type tumors, and there was no significant difference in expression between early and advanced cancers. In contrast, p53 overexpression did not occur often in the early stage of diffuse-type tumors, but it increased progressively as the tumor advanced. Analysis of patient survival revealed that p53 overexpression correlates significantly with a poor prognosis in diffuse-type gastric carcinoma (P = 0.003) but not in intestinal-type. Multivariate analysis showed that only pathological stage was an independent prognostic indicator. Our results suggest that p53 overexpression plays a different role in tumor carcinogenesis and progression of these two types of gastric cancers.     

Programmed cell death ligand 1 (PD-L1) expression on gastric cancer and its relationship with clinicopathologic factors

Background: Targeting the immune checkpoints in solid tumors becomes hot recently. Programmed cell death ligand 1 (PD-L1) is ligand for programmed death 1 (PD-1), which is known to negatively regulate T-cell activation. In the present study, we investigated the expression of PD-L1 in tumor specimens of gastric cancer and its relationships with clinicopathological variables and survival. Methods: The expression of PD-L1 in 132 surgically resected specimens of stage II and III gastric cancer was evaluated by immunohistochemistry in microarray tissue. Results: Expression of PD-L1 was observed in 50.8% (67/132) of gastric cancer tumor specimens. Patients whose tumor size over 5cm had a higher positive rate of PD-L1 expression. There was no relationship between the expression of PD-L1 and other clinicopathological variables including age, gender, clinical stage, location as well as histological differentiation. PD-L1 positive patients had significantly poorer survival than negative patients. The 5-year survival rates was 83.1% in those with PD-L1 negative patients and 50.7% for PD-L1 positive patients (P<0.001). The multivariate analysis indicated that both PD-L1 positive and Tumor-node-metastasis stage were independent prognostic factors in gastric cancer patients (P=0.001 and 0.025, respectively). Conclusions: The expression of PD-L1 was found in half of stages II and III gastric cancer patients. Positive of PD-L1 expression indicated poor survival in Chinese stages II and III gastric adenocarcinoma patients. These results may provide the clue for immunotherapy in the adjuvant treatment setting of gastric cancer patients.     

Clinical implications of N-cadherin expression in gastric cancer

Neo-expression of N-cadherin in cancer cells is regarded as a significant event in tumor progression via epithelial-mesenchymal transition (EMT). No reports have detailed the clinical impact of N-cadherin expression in gastric cancer. We retrospectively examined the co-expression of N-cadherin and E-cadherin in human gastric carcinoma and analyzed the clinicopathological significance of N-cadherin expression. One hundred and forty-six gastric cancer patients who received curative gastrectomy were enrolled. E-cadherin and N-cadherin immunoreactivity in cancer tissue was evaluated by the avidin-biotin-peroxidase complex technique. The correlation between N-cadherin and E-cadherin expression and clinicopathological parameters were analyzed. N-cadherin-positive and -negative expression were found in 31 and 115 patients, respectively. N-cadherin expression positively correlated with hematogenous recurrence (P < 0.01) and negatively correlated with patients' postoperative outcomes (P < 0.05). Moreover, only in the E-cadherin-preserved group was prognostic significance found according to N-cadherin expression (P < 0.01). We could not show a significant relationship between N-cadherin expression and EMT in gastric cancer. However, neo N-cadherin expression significantly affected patient's survival in gastric cancer. Therefore, we concluded that neo N-cadherin expression may be a useful prognostic marker independent of E-cadherin expression.     

UCH-LI acts as a novel prognostic biomarker in gastric cardiac adenocarcinoma

Gastric cardiac adenocarcinoma (GCA) accounts for a majority of gastric cancer population and harbors unfavorable outcome. Ubiquitin C-terminal hydrolase L1 (UCH-L1) belongs to the deubiquitinating enzyme family, which could regulate cell growth in human cancers. In the present study, expression of UCH-L1 was evaluated in 196 GCAs by immunohistochemistry using tissue microarray and its function on gastric cancer cells was measured. UCH-L1 expression was increased in GCA specimens, compared with their normal tissues and UCH-L1 overexpression is tightly correlated with tumor size and overall TNM stage. Log-rank analysis showed that UCH-L1 positive is reversely associated with cumulative survival (P<0.001). Multivariate Cox regression model showed that UCH-L1 overexpression is a remarkably negative predictor in GCA prognosis (Hazard Ratio=0.53, P<0.01), along with advanced TNM stage that is a known negative factor in gastric cancers (Hazard Ratio=0.33, P<0.05). Silencing of UCH-L1 reduced the ability of cell proliferation, colony formation, migration and invasion of gastric cancer cells. Our findings suggest that UCH-L1 is a promising prognostic biomarker for GCAs and might play an important role in the carcinogenesis of gastric cancer.     

Expression of SNCG,MAP2, SDF-1 and CXCR4 in gastric adenocarcinoma and their clinical significance

Objectives: The purpose of the study was to detect the expression of SNCG, MAP2, SDF-1 and CXCR4 in gastric adenocarcinoma, and to evaluate their roles in the carcinogenesis of gastric adenocarcinoma, development, invasion and metastasis as well as their clinical significance. Methods: The expression of SNCG, MAP2, SDF-1 and CXCR4 was detected by SP immunohistochemical method in 225 cases of gastric adenocarcinoma and 105 cases of nonneoplastic adjacent gastric tissue. The expression of SNCG, MAP2, SDF-1 and CXCR4 mRNA was also detected by RT-PCR method in 50 cases of gastric adenocarcinoma and 30 cases of nonneoplastic adjacent gastric tissue. Results: The expression of SNCG, MAP2, SDF-1 and CXCR4 in the gastric adenocarcinoma was remarkably higher than those in the nonneoplastic adjacent gastric tissue (P < 0.01); The positive expression of SNCG and MAP2 was correlated with the depth of tumor invasion and the metastasis of lymph nodes (P < 0.05), and that of SDF-1 and CXCR4 was correlated with the metastasis of lymph nodes (P < 0.05). Conclusions: SNCG, MAP2, SDF-1 and CXCR4 may play an important role in the carcinogenesis, progression, invasion and metastasis of gastric adenocarcinoma. However, it still needs more exploration whether they can serve as promising therapeutic targets of gastric adenocarcinoma.     

Decreased expression of SEMA3A is associated with poor prognosis in gastric carcinoma

Background/purpose: SEMA3A (semaphorin-3A), is a secreted protein that belongs to the semaphorin family and can function as both a chemoattractive agent or a chemorepulsive agent. SEMA3A has been shown to be a tumor suppressor in various cancers. This study investigated the expression of SEMA3A in gastric cancer and its prognostic value for gastric cancer patients. Methods: We examined the expression of SEMA3A in paired cancerous and matched adjacent noncancerous gastric mucosa tissues by real-time quantitative RT-PCR (qRT-PCR) and western blotting. In vitro, we evaluate the effects of SEMA3A on gastric cancer cell proliferation and migration by MTT, transwell and wound-healing assays. Furthermore, we analyzed SEMA3A expression in 128 patients who underwent resection procedures using immunohistochemistry. The relationships between the SEMA3A expression levels, the clinicopathological factors, and patient survival were investigated. Results: Our results revealed decreased SEMA3A mRNA (P = 0.0037) and protein (P = 0.033) expression in tumor tissue samples compared with matched adjacent non-tumorous tissue samples. Overexpression of SEMA3A inhibits gastric cancer cell proliferation and migration in vitro. Immunohistochemical staining data showed that SEMA3A expression was significantly decreased in 54.68% of gastric cancer cases. In addition, the chi-square test revealed that low SEMA3A expression was significantly correlated with poor differentiation (P = 0.015), Vascular invasion (P = 0.001), depth of invasion (P < 0.001), lymph node metastasis (P = 0.029), distant metastasis (P = 0.002) and advanced TNM stage (P = 0.003). SEMA3A expression was positively correlated with clinical TNM stage, that suggested the more advanced clinical TNM stage corresponding to the lower expression level of SEMA3A (r_s = -0.322, P < 0.001) by Spearman rank correlation analysis. Kaplan-Meier survival analysis demonstrated that low expression of SEMA3A was significantly correlated with a poor prognosis for gastric cancer patients (P < 0.001). The multivariate analysis revealed that SEMA3A expression was an independent prognostic factor of the overall survival rate of patients with gastric cancer. Conclusion: SEMA3A expression decreased significantly as gastric cancer progressed and metastasized, suggesting that SEMA3A might serve as a candidate tumor suppressor and a potential prognostic biomarker in gastric carcinogenesis.     

miR-143在胃癌中的表达及其临床病理意义

目的:分析miR-143在胃癌中的表达及其与临床病理特征的关系。方法:分别取胃癌手术标本32例及其癌旁组织,提取总RNA,采用茎环逆转录实时定量PCR方法检测miR-143在胃癌及其癌旁正常组织中的表达量,并分析其与临床病理特征关系。结果:与癌旁组织比较,miR-143在胃癌组织中表达显著下调(P0.05);miR-143的表达与细胞分化程度(P0.05)及淋巴结转移(P0.05)相关,与性别、年龄、血型、肿块位置、肿块大小、肿块侵润深度及肿瘤淋巴结转移分期无关。低分化胃癌组织的miR-143表达明显低于中高分化的标本(P0.05);有淋巴结转移胃癌组织的miR-143表达明显低于无淋巴结转移的胃癌组织(P0.05)。ROC曲线分析显示,miR-143评价胃癌细胞分化程度的特异性和敏感性可达75.0%和79.2%。结论:miR-143表达下调可能与胃癌的发生发展有关,miR-143可作为评价低分化胃癌的辅助指标。     

Expression of Tim-3 in gastric cancer tissue and its relationship with prognosis

As a negative regulatory molecule, T-cell immunoglobulin–and mucin domain-3 (Tim-3) plays a crucial role in the tumor immunological tolerance. In the present study, we aimed to determine the Tim-3 expression in gastric cancer tissue and its relationship with clinicopathological parameters and prognosis. The Tim-3 expression was assessed in 52 gastric cancer specimens and 15 gastritis tissues by flow cytometry, and gastritis tissues served as the control. As a result, we found that the Tim-3 expressions on CD4⁺T cells and CD8⁺T cells in gastric cancer tissue was significantly higher than those in gastritis tissue (P=0.022, P=0.047, respectively). The median expression level of Tim-3 on CD4⁺T cells were significantly correlated with clinicopathological parameters, such as tumor size, lymph node metastasis, the depth of tumor invasion and TNM staging (P=0.042, P=0.026, P=0.001, P=0.003, respectively), while it was not correlated with sex, age and histological subtype (all P>0.05). In CD8⁺T cells, the Tim-3 expression was relevant to tumor invasion and TNM staging (P=0.035, P=0.017, respectively), while it was irrelevant to other clinicopathological parameters (all P>0.05). Additionally, Kaplan-Meier survival curves showed that the median overall survival time of patients with lower Tim-3 expression was greater than that of patients with higher Tim-3 expression in CD4⁺T cells and CD8⁺T cells (χ²=18.036, P<0.001 and χ²=18.036, P<0.001, respectively). Moreover, the multivariate analysis revealed that the Tim-3 expression and TNM stage were independent prognostic factors for gastric cancer patients (P=0.029, P=0.043 and P=0.003, respectively). These results suggest that Tim-3 played an important role in the development and progression of gastric cancer, and it could be used as an independent prognostic factor for gastric cancer patients.     

Bridging integrator 1在胃腺癌中的表达及其预后价值

目的研究Bridging integrator 1（BIN1）在胃腺癌中的表达及其预后价值。方法通过免疫组化研究BIN1在234个胃腺癌组织样本中的表达,之后运用荧光定量PCR（RT-qPCR）和蛋白质印迹（Western blotting）技术对免疫组化结果进行进一步验证。结果通过免疫组化数据表明,在234个胃腺癌病例中,有128例的BIN1表达水平下降（54.7%）。此外,BIN1的表达水平与组织学分级、肿瘤侵袭、淋巴结转移及TNM分期显著相关（P〈0.05）。通过RT-qPCR和Western blotting分析,发现与非胃腺癌组织相比较,大多数肿瘤组织中的BIN1的转录和转录后水平下调（P=0.0015和P=0.012）。Kaplan-Meier存活曲线证实BIN1表达水平的下降与胃腺癌患者的预后不良有关。进一步的多因素分析结果提示BIN1是胃腺癌患者的总存活率的独立预后因子（HR=0.552,95%CI：0.354～0.862,P=0.009）。结论在胃腺癌中BIN1表达的下降可导致疾病预后不良,BIN1作为潜在的肿瘤抑制基因可能在防止肿瘤进展方面起重要作用。     

Smad4的表达与卵巢癌淋巴管生成及淋巴结转移之间的关系

目的观察Smad4和血管内皮生长因子(VEGF)-C在卵巢癌组织内的表达情况,分析Smad4和VEGF-C的表达与卵巢癌淋巴管生成及淋巴结转移之间的关系。方法取卵巢癌病例60例,其中,淋巴结转移组36例,无淋巴结转移组24例。应用免疫组化法和Westernblot技术观察Smad4和VEGF-C在卵巢癌组织内的表达。以D2-40作为淋巴管内皮特异性标记物,检测卵巢癌组织内淋巴管生成情况。结果 Smad4表达于卵巢癌细胞胞浆和胞核内,其在无淋巴结转移组的表达率明显高于其在有淋巴结转移组的表达率。Smad4表达阳性组的淋巴管数密度(LVD)明显低于Smad4表达阴性组的LVD。VEGF-C主要表达于卵巢癌细胞胞浆内,其在淋巴结转移组的表达率明显高于其在无淋巴结转移组的表达率。Smad4的表达与VEGF-C的表达呈显著的负相关性。Western blot检测结果表明,VEGF-C蛋白在有淋巴结转移卵巢癌组织中的表达量高于其在无淋巴结转移卵巢癌组织内的表达量,而Smad4在有淋巴结转移卵巢癌组织内的表达量明显低于其在无淋巴结转移组的表达量。结论 Smad4与VEGF-C的表达呈负相关,Smad4可能通过调节VEGF-C蛋白的表达而抑制卵巢癌淋巴管生成和淋巴道转移。     

Prognostic role of SPARC expression in gastric cancer: a meta-analysis

Introduction

Secreted protein acidic and rich in cysteine (SPARC) is involved in regulating cell adhesion, proliferation, migration, and tissue remodeling. We performed a meta-analysis to evaluate the association between SPARC expression and the clinicopathologic features and outcomes of gastric cancer patients.

Material and methods

Publications that assessed the clinical or prognostic significance of SPARC in gastric cancer up to October 2013 were identified. A meta-analysis was performed to clarify the association between SPARC expression and clinical outcomes.

Results

Ten studies, including 1417 cases, met the inclusion criteria. The data were analyzed and the results show that SPARC is not significantly associated with the depth of gastric cancer invasion (odds ratio (OR) = 1.17, 95% confidence interval (CI): 0.60–2.29, Z = 0.47, p = 0.64) or tumor differentiation (OR = 0.59, 95% CI: 0.22–1.58, Z = 1.06, p = 0.29). Moreover, SPARC was not significantly correlated with lymph node metastasis (OR = 0.72, 95% CI: 0.37–1.41, Z = 0.96, p = 0.34). However, SPARC overexpression was highly correlated with reduced overall survival (relative risk (RR) = 1.78, 95% CI: 1.52–2.09, Z = 7.10, p = 0.43).

Conclusions

The SPARC may play an important role in the progression of gastric cancer, and SPARC overexpression is closely correlated with poor patient survival. The SPARC is a potential clinical marker for the survival of gastric cancer patients; however, well-designed prospective studies are needed to confirm these findings.