Correlation between E-cadherin and FOXO3a expression in gastric can-cer tissues and cells

AIM: To investigate the expression of E-cadherin and forkhead box protein O3a (FOXO3a) in gastric cancer tissues and cells, and its correlation with cell viability. METHODS: The expression of E-cadherin and FOXO3a was detected by immunohistochemical staining in 53 specimens of gastric cancer tissues and their adjacent tissues, and the relationship between their expression and clinicopathological characteristics were analyzed. E-cadherin-over-expressing gastric cancer AGS cells were constructed by lentivirus-mediated cell transfection, and the protein expression of E-cadherin and FOXO3a was detected by immunocytochemistry method. The expression of E-cadherin, FOXO3a, Akt, Bcl-2 and Bax was determined by Western blot. The cell viability was detected by CCK-8 assay. RESULTS: The positive expression rates of E-cadherin and FOXO3a proteins in gastric cancer tissues were both significantly lower than those in their adjacent tissues (P<0.05). E-cadherin positive expression in gastric cancer tissues was significantly related to tumor grade and TNM stage (P<0.05), but not related to age, sex, location, T stage or lymph node metastasis. FOXO3a positive expression was significantly related to tumor grade (P<0.05), but not related to age, sex, location, TNM stage, T stage or lymph node metastasis. The expression of E-cadherin was positively correlated with FOXO3a expression in gastric cancer tissues (r=0.376, P=0.003). After over-expression of E-cadherin, the viability of gastric cancer AGS cells was significantly inhibited, the expression of FOXO3a, Bcl-2 and Bax was significantly increased, and the expression of Akt was significantly decreased. CONCLUSION: E-cadherin and FOXO3a are involved in the development of gastric cancer, and E-cadherin may affect the viability of gastric cancer cells by regulating Akt/FOXO3a signaling pathway.     

Significance of STC1 expression in peripheral blood and tissue of gastric carcinoma

AIM: To investigate stanniocalcin 1 (STC1) mRNA expression in the blood and tissue of gastric carcinoma. METHODS: The samples of peripheral blood and tumor tissues were collected from 74 patients with stage I-IV gastric carcinoma. STC1 mRNA was detected by RT-PCR, STC1 protein in tumor tissue was also detected by immunohistochemical method. RESULTS: The expression of STC1 mRNA in blood was significantly correlated with multiple histopathological prognostic factors, including primary tumor size, number of positive lymph nodes, and TNM stage. STC1 mRNA was not detected in the blood of volunteers without cancer, but detected in all gastric carcinoma tissue, and STC1 protein was expressed in all gastric carcinomas. CONCLUSION: STC1 is proposed as a novel, specific, and clinically useful molecular marker for detecting occult gastric carcinoma cells in blood. STC1 expression may play an important role in the progression of gastric carcinoma.     

Expression and prognostic significance of SLP-2 in gastric cancer

AIM: To investigate the expression of the red cell membrane integration protein SLP-2 (stomatin-like protein 2) in gastric cancer tissues and to analyze its correlation with clinicopathological manifestations and prognosis. METHODS: One hundred and ninety gastric cancer tissue samples with detailed clinical information were collected from the Department of Pathology, Sun Yat-sen University Cancer Center. The protein expression of SLP-2 in ganstric cancer was detected by the method of immunohistochemistry. The relationships between SLP-2 expression and the clinicopathological manifestations were evaluated. RESULTS: The positive rate of SLP-2 in gastric cancer tissue was 63.2% (120/190). SLP-2 expression was relevant to infiltration depth, TNM stage and lymph node metastasis (P<0.05). However, no statistical difference was observed in the SLP-2 expression associated with sex, age, differentiation, tumor size and distant metastases. Kaplan-Meier survival curves revealed that increased expression of SLP-2 was associated with poor prognosis in gastric adenocarcinoma patients (P<0.01). Based on the univariate analysis, 7 factors were found to have statistical significance of associations with overall survival, including SLP-2 expression, lymph node metastasis, histological grade, tumor size, invasive depth, distant metastases and the 7th edition of the UICC TNM classification. Only the tumor size and the 7th edition of the UICC TNM classification were independent prognostic factors for overall survival in the multivariate analysis. CONCLUSION: SLP-2 is highly expressed in gastric adenocarcinoma tissues and may play an important role in tumor progression and metastasis. Although SLP-2 is not an independent prognostic factor, it may influence the prognosis of gastric cancer. Increased expression of SLP-2 can be used for predicting unfavorable prognosis in gastric adenocarcinoma patients.     

Relationship between c-erbB-2, BCSG1 expression and recurrence,metastasis in breast cancer

AIM: To assess the significance of c-erbB-2, BCSG1 (breast cancer specific gene-1) expression and other parameters in recurrence or metastasis of breast cancer. METHODS: The expression of c-erbB-2, BCSG1, and ER, PR, MVD, VEGF, VEGF-C, FLT-4, LVD were determined with the SP immunohistochemical method in 58 cases of invasive breast cancer patients occurred over 5 years. The cases were used to analyze the effect of c-erbB-2, BCSG1, VEGF-C and ER, PR, MVD, VEGF, FLT-4, LVD expression on clinical-pathological manifestations and prognosis in breast cancer. RESULTS: The expression rates of c-erbB-2, BCSG1, VEGF-C, LVD were respectively 25.9%, 62.1%, 36.2%, 32.8% in association with the lymph node metastasis and recurrence of breast cancer (P<0.05), the expression rate of MVD was also increased significantly (P＜0.05). CONCLUSION: The c-erbB-2, BCSG1, VEGF-C, LVD are highly expressed and strongly correlated with the lymph node metastasis and recurrence of breast cancer, of which BCSG1 may be used as a predictor of prognosis.     

Expression of chemokine receptor CCR7 and VEGF-C is associated with prognosis of breast carcinoma

AIM: To explore the protein levels of chemokine receptor 7 (CCR7) and vascular endothelial growth factor (VEGF)-C in breast carcinoma, and to investigate the effects of CCR7 and VEGF-C on prognosis of breast carcinoma. METHODS: The protein expression levels of CCR7 and VEGF-C in the breast carcinoma tissues and normal breast tissues were detected by the method of immunohistochemistry. At the same time, the relationship between clinicopathologic characteristics and the protein expression of CCR7 and VEGF-C in the breast carcinoma tissues was analyzed. The relationship between the protein expression of CCR7 and VEGF-C and survival time of the breast cancer patients was estimated by Kaplan-Meier method.RESULTS: The positive expression rates of CCR7 and VEGF-C in the breast carcinoma tissues were significantly higher than those in the normal breast tissues (P<0.01). A positive correlation was observed between the protein expression of CCR7 and the protein expression of VEGF-C in the breast carcinoma tissues (r=0.613, P<0.01). The protein expression of CCR7 and VEGF-C was correlated with lymph node metastasis and TNM stage (P<0.05), but both were not related to patients' age, primary tumor size, estrogen receptor and progesterone receptor. The survival time of the patients with CCR7 and VEGF-C positive expression was significantly shorter than that of the patients without the expression (P<0.05).CONCLUSION: The positive expression of CCR7 and VEGF-C proteins is associated with the prognosis of breast cancer, and combined detection of CCR7 and VEGF-C protein expression levels may be helpful to judge the prognosis of breast cancer.     

Expression of chemokine CXCL17 and its clinical relevance in gastric carcinoma

AIM: To investigate the expression and distribution of chemokine CXCL17 in gastric cancer and its clinical significance.METHODS: The CXCL17 expression was detected by real-time PCR and immunohistochemistry. The correlation between the CXCL17 expression and clinicopathological features was statistically analyzed and Kaplan-Meier survival analysis was used to evaluate the prognosis.RESULTS: A lower expression levels of CXCL17 were observed in the tumor tissues compared with the paired normal tissues (P < 0.05). Down-regulation of CXCL17 was associated with the degree of tumor differentiation and the size of tumor at primary site (P < 0.05). Kaplan-Meier survival analysis showed that increased CXCL17 in the tumor tissues was associated with longer survival time.CONCLUSION: The result might illustrate that CXCL17 acts as a key factor in the prognosis of gastric cancer and is closely associated with the progression of gastric cancer.     

Expression of Foxp3+ Tregs and PD1 in gastric cancer tissues and their correlation with clinicopathological factors and prognosis

AIM: To investigate the expression of Foxp3⁺ regulatory T cells (Foxp3⁺ Tregs) and programmed death receptor 1 (PD1) in gastric cancer tissues and their association with clinicopathological factors and prognosis of the patients. The correlation between the 2 molecules was also analyzed at the same time. METHODS: The tumor sections from 111 gastric cancer patients were stained for Foxp3 and PD1 by the method of immunohistochemistry. The associations of the expression levels of these 2 molecules with clinicopathological factors involved in the disease progression and prognosis were statistically analyzed. The relationship of their expression was detected. RESULTS: Foxp3⁺ Tregs and PD1 were expressed in the gastric cancer tissues, and PD1 was expressed in the tumor infiltrating lymphocytes (TILs). The expression of Foxp3 and PD1 was correlated with lymph node metastasis, clinicopathological stage and prognosis of gastric cancer patients. The expression of these 2 determinants in the patients with lymph node metastasis and an advanced clinicopathological stage was distinctly higher (P <0.05). The patients with positive expression of the 2 indexes presented a lower overall survival rate and worse prognosis (P <0.05). A significantly positive correlation between the infiltration of Foxp3⁺ Tregs and the expression of PD1⁺ TILs was also observed (P <0.01).CONCLUSION: Foxp3⁺ Tregs and PD1⁺ TILs co-infiltrate in the gastric cancer tissues, which can be used as biological markers to predict the disease progression and prognosis.     

Effects of phillyrin on VEGF and endostatin expression in Lewis lung carcinoma

AIM: To investigate the effects of phillyrin on vascular endothelial growth factor (VEGF) and endostatin expression in lung tumor tissues isolated from Lewis lung carcinoma. METHODS: The expression of VEGF and endostatin in control individuals and the patients with lung cancer was determined by immunohistochemistry. In the animal experiment, 5 groups of animals were examined: control, tumor model, and tumor model with 3 different concentrations of phillyrin treatments. For preparation of transplanted tumor model, Lewis cells were subcutaneously injected into the right limb armpit of the nude mice. After that, phillyrin was administered via oral gavage once daily for 20 d at dose of 5 or 10 g/kg, or twice daily at 10 g/kg. Lung tumor tissues isolated from each group were observed by hematoxylin-eosin staining. VEGF and endostatin expression were examined by immunohistochemistry. RESULTS: VEGF expression was increased in lung tumor tissues as compared with normal and pericarcinous tissues, while endostatin expression was decreased. Phillyrin significantly inhibited the tumor size and tumor tissue density dose-dependently, which was accompanied with a decrease in VEGF expression and an increase in endostatin expression. CONCLUSION: Phillyrin inhibits the development of lung tumor through reducing VEGF expression and increasing endostatin expression.     

Differential expression of Golgi mannosidaseⅡ in different differentiated gastric carcinoma cell lines and tissues

AIM: To explore the role of Golgi mannosidase Ⅱ(GMⅡ) in the development of gastric carcinoma by analysis of the relationship between differential expression of GMⅡ and differentiation of gastric carcinoma cell lines and tissues. METHODS: Thirty cases of human normal gastric tissues and 38 cases of gastric adenocarcinoma tissues were selected. Three different differentiated gastric carcinoma cell lines (MKN-28, SGC-7901 and BGC-823) and a normal gastric epithelial cell line GES-1 were cultured in vitro. The mRNA levels of GMⅡ were detected by RT-PCR, and the protein expression was detected by immunohistochemistry and Western blotting. RESULTS: GMⅡ was mainly distributed in cytoplasm. The positive rates of GMⅡ in 30 cases of human normal gastric tissues, 8 cases of well-differentiated, 18 cases of moderately-differentiated and 12 cases of poorly-differentiated gastric cancer tissues were 53% (16/30), 63% (5/8), 83% (15/18) and 100% (12/12), respectively. The expression of GMⅡ was gradually increased in normal gastric epithelial cell line and in well, moderately and poorly-differentiated gastric cancer cell lines by cell-attached coverslip. Compared with normal gastric epithelial cell line, 3 gastric carcinoma cell lines showed the higher expression of GMⅡ at mRNA and protein levels (P<0.05). Furthermore, GMⅡ expression in poorly-differentiated gastric carcinoma cell line BGC823 was the highest, and the lowest expression of GMⅡ was the well-differentiated cell line MKN-28. Compared with normal gastric epithelial tissues, gastric carcinoma tissues showed the higher expression of GMⅡ at mRNA and protein levels (P<0.05), and the highest was the poorly-differentiated carcinoma tissues. The expression of GMⅡ at mRNA and protein levels in normal gastric tissues was the lowest. CONCLUSION: GMⅡ is involved in the development and progression of gastric cancer. The expression of GMⅡ is highly related to the poorly-differentiated gastric cancer.     

Central role of GRP78 in growth of gastric carcinoma cells

AIM: To explore the effect of glucose-regulated protein 78 (GRP78) on the gastric carcinogenesis. METHODS: GPR78 expression patterns were examined in 34 specimens from gastric carcinoma patients using the immunohistochemistry (IHC) assay, and in 10 specimens using Western blotting analysis. In addition, the expression of GPR78 and cyclin D1 was detected in human gastric cancer cell lines SGC7901 and SGC7901-H78 (overexpressing GRP78) by Western blotting. RESULTS: By IHC assay, GRP78 was found to be highly expressed in the cytoplasm of gastric carcinomas as compared with the adjacent non-malignant tissues and corresponding normal tissues. GRP78 expression was positively correlated with gender and histological differentiation (P<0.05), but not with age, tumor stage and lymph node metastasis (P>0.05). Furthermore, we found that with the increased expression of GRP78 in SGC7901-H78 cells, the expression of cyclin D1 was also elevated. CONCLUSION: GRP78 might be a key player to be involved in the growth of gastric cancer.     

Inhibition of 17-DMAG on VEGF expression in transplanted human gastric cancer in nude mice

AIM: To observe the anti-tumor effects of heat shock protein 90(HSP90) inhibitor 17-dimethylaminoethylamino-17 demethoxygeldanamycin (17-DMAG) on the tumor growth and angiogenesis in implanted gastric cancer nude mouse model. METHODS: Human gastric cancer cell HGC-27 was subcutaneous inoculation into the nude mice to develop a tumor model. Ten days later, 24 mice with implanted tumor were randomly divided into 3 groups: 17-DMAG group (receiving 17-DMAG at dose of 25 mg/kg), control group (treated with NS at dose of 10 mL/kg) and 5-fluorouracil(5-FU) group (treated with 5-FU at dose of 20 mg/kg). Four weeks after treatment, the tumor volume and weight, and the inhibitory rates of tumor growth were evaluated. In the meantime, the expression of CD31 was detected by immunohistochemical staining. The expression of vascular endothelial growth factor (VEGF) was determined by Western blotting. RESULTS: The size of xenografts in 17-DMAG treatment group was (288.10±23.32)mm³, and that in 5-FU treatment group was (366.37±26.42)mm³, both were significantly smaller than that in control group (957.66±117.51)mm³. The tumor weight in 17-DMAG treatment group was (0.41±0.02)g, significantly less than that in control group (1.12±0.08)g. The inhibitory rate of 17-DMAG was 63%. A significant decease of MVD in 17-DMAG group (21.72±1.24) was observed as compared to 5-FU group (36.70±1.51) and control group (37.78±1.68). The expression of VEGF in 17-DMAG group (15.39±4.37) was significantly lower than that in 5-FU group (26.11±6.26) and control group (36.45±7.45). CONCLUSION: HSP90 inhibitor 17-DMAG suppresses the expression of VEGF and the angiogenesis of the gastric cancer to inhibit the tumor growth.     

MicroRNA-330 inhibits growth and migration of gastric cancer cells by directly targeting EGR-2

AIM:To explore the function and significance of microRNA-330 (miR-330) in the development of gastric cancer. METHODS:Forty-eight cases of gastric cancer tissues and paired adjacent tissues were collected in Department of Oncology, Affiliated Hospital of Gansu University of Chinese Medicine, and the expression levels of miR-330 were detected by RT-qPCR. The expression levels of miR-330 in the gastric cancer cells and human gastric epithelial GES-1 cells were evaluated by RT-qPCR. The viability, colony formation and migration of gastric cancer cells after transfected with miR-330 inhibitor or miR-330 mimic were analyzed by CCK-8 assay, colony formation assay and Transwell assay, respectively. Furthermore, miR-330 target gene was predicted by miRanda target gene prediction database. RESULTS:miR-330 expression was down-regulated both in gastric cancer tissues and gastric cancer cells (P<0.05). The expression levels of miR-330 were negatively associated with the tumor size, lymph metastasis, pathological grade stage and T stage (P<0.05). The viability, colony formation and migration of gastric cancer cells were significantly increased after transfected with miR-330 inhibitor (P<0.05). However, the viability, colony formation and migration of gastric cancer cells were significantly decreased after transfected with miR-330 mimic (P<0.05). Furthermore, EGR-2 was the direct target gene of miR-330. CONCLUSION:miR-330 suppresses gastric cancer cell growth and migration, and the mechanism may be related to its direct target gene EGR-2, suggesting that miR-330 may be used as a potential new target for diagnosis and targeted therapy for gastric cancer.     

Study of annexin A2 expression in gastric cancer by proteomics and tissue microarray

AIM: To investigate the differential expression of annexin A2 (ANXA2) in gastric carcinoma and to analyze the relationship between ANXA2 expression and clinicopathological parameters of gastric carcinoma. METHODS: Pure gastric adenocarcinoma cells (GAC) and normal gastric epithelial cells (NGEC) in 15 patients with gastric cancer were acquired by laser capture microdissection (LCM). All peptide specimens after trypsin digestion were labeled with ¹⁸O/¹⁶O. Quantitatively identification of differential expression of the proteins betweem GAC and NGEC was performed by Nano-RPLC-MS/MS. The expression of ANXA2 in the 2 kinds of tissues was detected by Western blotting. Tissue microarray containing 75 pairs of gastric carcinoma and para-carcinoma tissues was used and the expression of ANXA2 in these specimens was detected by the method of immunohistochemistry (IHC). The relationship between ANXA2 expression and clinicopathological parameters of the pateints with gastric carcinoma was analyzed. RESULTS: A total of 78 differential proteins were identified and ANXA2 was up-expressed in GAC (2.32∶ 1), which was confirmed by Western blotting (P<0.01). The results of IHC showed that the correlations between the expression level of ANXA2 protein and invasive depth (T stage), lymph node metastasis (N stage), histological differentiation, TNM stage and the size of tumor were observed (P<0.01), but the correlations between the ANXA2 expression and sex, age and distant metastasis (M stage) were not found (P>0.05). CONCLUSION: The up-expressed ANXA2 may play an important role in the biological behavior of gastric cancer.     

Effects of HuR on cell viability,migration and invasion of gastric cancer cell line MGC-803

AIM:To investigate the effects of HuR on cell function of gastric cancer cell line MGC-803. METHODS:The mRNA expression level of HuR was detected by RT-qPCR in the tumor samples of 80 gastric cancer patients diagnosed clinically. HuR gene knock-down was achieved by transfection of si-HuR into the MGC-803 cells. The invasion, migration and viability of MGC-803 cells were measured by the scratch wound hearing, Transwell and CCK-8 assays, respectively. RESULTS:High mRNA expression of HuR was observed in 67 cases (84%) of gastric cancer tissues as compared with their control samples. Furthermore, knock-down of HuR expression effectively inhibited the invasion, migration and viability of the MGC-803 cells (P<0.05), indicating that HuR play an important role in gastric cancer as an oncogene. CONCLUSION:Abnormal expression of HuR is correlated with the progression of gastric cancer. Knock-down of HuR expression inhibits the invasion, migration and viability of MGC-803 cells.     

Significance and alterations of p14ARF gene of CDKN2A locus in gastric cancer

AIM:To investigate the significance and changes of p14^ARF gene in gastric cancer.METHODS:The tumors and gastric tissues neighboring carcinoma from 48 patients with gastric cancer were studied. The homozygous deletions, mutations, methylation of the CpG islands, and mRNA expression of p14^ARF gene were assessed by PCR, PCR-SSCP, PCR based methylation assay, and RT-PCR.RESULTS:①The homozygous deletion rate of p14^ARF was 31.3% (15/48), and no homozygous deletions were examined in all the gastric tissues neighboring tumor. ②There were no point mutations of p14^ARF in 33 gastric cancers without homozygous deletion and in the matched gastric tissues adjacent to tumor. ③Methylation rate of the CpG islands of p14^ARF was significantly higher in gastric cancers(47.9%, 23/48) than that in gastric tissues neighboring cancer (4.2%, 2/48)(P＜0.01).④ No expression of p14^ARF mRNA was detected in 45.8%(22/48) of gastric cancers. Moreover, the negative rate (100%, 3/3) of p14^ARF mRNA of gastric cancers with the combined methylation of exons 1β and 2 was significantly higher than that (15%, 3/20) of the sole methylation of exon2(P＜0.05). CONCLUSION:p14^ARF gene is frequently inactivated by homozygous deletion and methylation of the 5' CpG islands in gastric cancer, which may play an important role in the development of gastric cancer.     

Expression of miR-143 and its clinicopathologic significance in gastric cancer

AIM: To investigate the expression of miR-143 and its association with clinicopathologic features in gastric cancer.METHODS: The expression level of miR-143 in 32 cases of gastric cancer and matched non-tumor adjacent tissue specimens was examined using stem-loop real-time RT-PCR. The relationship between the expression of miR-143 and its clinicopathologic features of gastric cancer was analyzed.RESULTS: The expression level of miR-143 was significantly lower in the tumor tissues than that in the adjacent tissues (P<0.05). Down-regulated miR-143 expression was associated with the cell differentiation (P<0.05) and lymph node metastasis (P<0.05) in gastric cancer patients. No significant association was found between the expression of miR-143 and the status of gender, age, blood type, tumor location, tumor size, depth of tumor invasion and tumor node metastasis stage.CONCLUSION: It is possible that miR-143 plays an important role in the generation and progression of gastric cancer. The expression level of miR-143 may be a valuable adjuvant parameter for predicting the poorly differentiated gastric cancer.