Clinical implications of micro lymph node metastasis for patients with gastric cancer.

BACKGROUND: Lymph node size is considered as a criterion for possible lymph node metastasis in imageology. Micro lymph nodes are easily overlooked by surgeons and pathologists. This study investigated the influencing factors and prognosis of micro lymph node metastasis in gastric cancer. METHODS: 191 eligible gastric cancer patients who underwent D2 lymphadenectomy from June 2016 to June 2017 in the Third Surgery Department at the Fourth Hospital of Hebei Medical University were retrospectively analyzed. Specimens were resected en bloc and the postoperative retrieval of micro lymph nodes was carried out by the operating surgeon for each lymph node station. Micro lymph nodes were submitted for pathological examination separately. According to the results of pathological results, patients were divided into the "micro-LNM (micro lymph node metastasis)" group (N = 85) and the "non micro-LNM" group (N = 106). RESULTS: The total number of lymph nodes retrieved was 10,954, of which 2998 (27.37%) were micro lymph nodes. A total of 85 (44.50%) gastric cancer patients had been proven to have micro lymph node metastasis. The mean number of micro lymph nodes retrieved was 15.7. The rate of micro lymph node metastasis was 8.1% (242/2998). Undifferentiated carcinoma (90.6% vs. 56.6%, P = 0.034) and more advanced Pathological N category (P < 0.001) were significantly related to micro lymph node metastasis. The patients with micro lymph node metastasis had a poor prognosis (HR for OS of 2.199, 95% CI = 1.335-3.622, P = 0.002). For the stage III patients, micro lymph node metastasis was associated with shorter 5-year OS (15.6% vs. 43.6%, P = 0.0004). CONCLUSIONS: Micro lymph node metastasis is an independent risk factor for poor prognosis in gastric cancer patients. Micro lymph node metastasis appears to be a supplement to N category in order to obtain more accurate pathological staging.

Up-regulation of KLF17 expression increases the sensitivity of gastric cancer to 5-fluorouracil.

It has been reported that the expression of Krüppel-like factor 17 (KLF17) was associated with the occurrence, development, invasion, metastasis and chemotherapy resistance of various tumors. However, the detailed mechanisms by which KLF17 promotes chemotherapy resistance in gastric cancer (GC) have not been fully investigated. In the present study, we collected the GC tissues and non-tumor tissues (matched adjacent normal tissues with corresponding GC tissues) of 60 GC patients, used qRT-PCR, Western blot and immunohistochemistry assay to analyze the relationship between the expression of KLF17 and the clinical pathological data of the patients. The effect of KLF17 on the sensitivity of GC cell lines to 5-fluorouracil (5-FU), and the potential mechanism were detected by MTS assay, Flow cytometry assay, and Western blot. Compared with non-tumor tissues, the expression level of KLF17 in GC tissue was significantly down-regulated, and the expression level of KLF17 in GES-1 cell line and GC cell lines also had a similar trend. Down-regulated expression of KLF17 is related to tumor size, invasion, regional lymph node metastasis, and TNM staging. Furthermore, through upregulating the expression of KLF17, the sensitivity of BGC-823 and SGC-7901 cell lines to 5-FU was obviously increased. Mechanistically, upregulation the expression of KLF17 can inhibit the expressions of P-glycoprotein (P-gp), multidrug resistance protein 1 (MRP1), and B-Cell lymphoma-2 (BCL-2), which have been reported to be associated with drug resistance and cell proliferation. Collectively, these data implied that KLF17 has the biological effect of inhibiting chemotherapy resistance of GC, and it could be a potential strategy for the GC chemotherapy resistance.

Inhibitory effect of siRNA-Annexin A7 on growth, migration, and invasion in BGC823 cells and gastric cancer xenograftsin nude mice.

OBJECTIVE: To explore the inhibitory effect of siRNA-Annexin A7 on growth, migration, and invasion of transplanted gastric cancer in nude mice. METHODS: The siRNA sequence targeting to human Annexin A7 gene was designed, and based on that a pair of complementary oligonucleotides were synthesized, annealed, and cloned into plasmid pGenesil-1.1 to construct recombinant plasmid siRNA-Annexin A7. Transplanted gastric cancer model was established by injecting s.c. nude mice with human gastric cancer BGC823 cells, and siRNA-Annexin A7 was injected into the tumors formed. The nude mice were observed for clinical manifestation relying on the size and weight of transplanted tumors. The tumor tissue and angiogenesis were examined by pathologic sections. Flow cytometry was used to detect the changes of cell cycle. Western blot and qRT-PCR were used to analyze the expression of PCNA, P27, MMP-2, and TIMP-2. RESULTS: Both the size and weight of transplanted tumors of nude mice injected with siRNA-Annexin A7 were less than those of control groups (P<0.05). The examination of pathologic sections showed that, compared with in the control group, obvious necrosis of tumor cells was observed in siRNA-Annexin A7 group. The cells in stage S were fewer in siRNA-Annexin A7 group than those in the other two groups, while the cells in stage G0/G1 were much more in siRNA-Annexin A7 group. The results of western blot and qRT-PCR confirmed that the expression of PCNA and MMP-2 was down-regulated, whereas the expression of p27 was up-regulated. CONCLUSION: Gastric cancer xenografts were established in nude mice with human gastric cancer BGC823 cells. The volume and weight of tumor were decreased after inhibition of Annexin A7 expression in BGC823 cells. Tumor cells were arranged sparsely after inhibition of Annexin A7 expression in BGC823 cells. The siRNA-Annexin A7 inhibits Annexin A7 expression in transplanted gastric cancer of nude mice, and influences the growth, migration, and invasion of tumors by down-regulating the expression of PCNA and MMP-2, as well as up-regulating the expression of p27.

Downregulation of annexin A7 decreases proliferation, migration, and invasion of gastric cancer cells by reducing matrix metalloproteinase 1 and 9 expression.

High annexin A7 expression is a potential indicator of lymphatic metastasis and poor prognosis in patients with gastric cancer (GC). The mechanism underlying the effects of annexin A7 on GC cells remains unclear. In patients with GC, primary adenocarcinoma tissues had higher annexin A7 expression than adjacent non-cancerous tissues (P < 0.05). Among three human GC cell lines with high, moderate, and low levels of differentiation, respectively, the cell line with the lowest level of differentiation displayed the highest level of annexin A7 expression. We transfected cells of the human GC cell line BGC823 with short interfering RNAs (siRNAs) targeting annexin A7 and investigated the effects on signaling pathways related to cancer progression by quantitative real-time PCR and western blot. The silencing of endogenous annexin A7 suppressed the proliferation, migration, and invasion abilities of the BGC823 cells. In the cells treated with annexin A7 siRNA, the expression of p16, p21, and p27 was significantly upregulated while that of proliferating cell nuclear antigen (PCNA), cyclin A, cyclin D1, cyclin E1, matrix metalloproteinase-2 (MMP-2), MMP-9, and intercellular cell-adhesion molecule-1 (ICAM-1) was significantly downregulated compared with that in control cells. Our results suggest that the downregulation of endogenous annexin A7 inhibits GC cell proliferation, migration, and invasion by impacting cell cycle regulators and the expression of MMP-1, MMP-2, and ICAM-1. Targeting annexin A7 may represent a valuable strategy for the diagnosis and clinical treatment of GC.

Formononetin inhibits colon carcinoma cell growth and invasion by microRNA­149­mediated EphB3 downregulation and inhibition of PI3K/AKT and STAT3 signaling pathways.

Formononetin (Form), a phytoestrogen extracted from the roots of Astragalus membranaceus, is one of the fundamental herbs used in traditional Chinese medicine because of its protective effects against certain malignant tumors. However, its role in colon carcinoma cells and the underlying molecular mechanisms have not been completely elucidated. The present study aimed to demonstrate that Form significantly inhibited the proliferation and invasion of the colon carcinoma cell lines SW1116 and HCT116. Mechanistic studies have suggested that Form suppresses colon carcinoma cell growth by downregulating cell cycle­associated protein (cyclin D1) expression and arresting the cell cycle at the G0­G1 checkpoint. Further studies revealed that treatment with Form inhibits matrix metalloproteinase (MMP)2 and MMP9 expression. Aditionally, the results demonstrated that Form significantly increased microRNA (miR)­149 expression. Following miR­149 overexpression in SW1116 and HCT116 cells using an miR­149 mimic, cell viability and Ephrin type­B receptor 3 (EphB3) levels decreased. Furthermore, the inhibitory effects of Form were associated with phosphatidylinositol 3­kinase (PI3K)/protein kinase B (AKT) and signal transducer and activator of transcription 3 (STAT3) signaling pathways. These results indicated the suppressive effect of Form on colon carcinoma cell proliferation and invasion, possibly via miR­149­induced EphB3 downregulation and the inhibition of the PI3K/AKT and STAT3 signaling pathways. Overall, Form may be used as a novel candidate for the clinical treatment of colorectal cancer in the future.

Inhibitory effects of CP on the growth of human gastric adenocarcinoma BGC-823 tumours in nude mice.

Objective To investigate the potential antitumour effects of [2-(6-amino-purine-9-yl)-1-hydroxy-phosphine acyl ethyl] phosphonic acid (CP) against gastric adenocarcinoma. Methods Human BGC-823 xenotransplants were established in nude mice. Animals were randomly divided into control and CP groups, which were administered NaHCO3 vehicle alone or CP dissolved in NaHCO3 (200 µg/kg body weight) daily, respectively. Tumour volume was measured weekly for 6 weeks. Resected tumours were assayed for proliferative activity with anti-Ki-67 or anti-proliferating cell nuclear antigen (PCNA) antibodies. Cell apoptosis was examined using terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assays and with caspase-3 immunostaining. Proteins were measured by Western blotting. Results There was a significant reduction in tumour volume and a reduced percentage of Ki-67-positive or PCNA-positive cells in the CP group compared with the control group. The percentage of TUNEL-positive or caspase 3-positive cells significantly increased following CP treatment compared with the control group. Tumours from the CP group had higher levels of phosphorylated-extracellular signal-regulated kinase (p-ERK) and phosphorylated-AKT (p-AKT) compared with control tumours. Conclusion CP treatment inhibited tumour growth and induced tumour cell apoptosis in a nude mouse model of BGC-823 gastric adenocarcinoma. Activation of the AKT and ERK signalling pathways may mediate this antitumour activity.

Gastrointestinal stromal tumor (GIST) with liver metastases: An 18-year experience from the GIST cooperation group in North China.

Approximately 40% to 50% of gastrointestinal stromal tumor (GIST) patients will have recurrence or metastases after resection of the primary lesion, and the most common affected sites will be liver and peritoneum. Imatinib has been considered as the first-line therapy of metastatic GIST. Surgery for metastases is proposed when possible. Furthermore, there are controversies concerning hepatic resection and systemic tyrosin kinase inhibitors (TKIs). The therapeutic conditions and long-term outcome of GIST patients with liver metastases in northern China remain unknown.The clinical, pathological, and follow-up data of 144 GIST patients, who had liver metastases between June 1996 and June 2014 from 3 tertiary cancer centers in northern China, were reviewed.Thirty-two cases (22.2%) had hepatectomy with 23 (23/32, 71.9%) R0 resections and 9 (9/32, 28.1%) R1/R2 resections, respectively. Twenty-three patients were given imatinib postoperatively. Furthermore, 98 (68.1%) patients were given TKIs only to control disease progression, and sunitinib was considered after imatinib failure in 12 patients. The 1-, 3- and 5-year survival rate was 82%, 51%, and 24%, with a median overall survival of 48 months for all patients. Patients who had hepatic resection combined with TKIs had a tendency of improved outcome, and the median survival time was 89 months. This was in contrast to patients who received TKIs only, in which median survival time was 53 months. Patients who received imatinib plus sunitinib had a tendency of longer survival time, compared with patients who received imatinib only (not reached vs 50 months).TKIs combined with hepatic resection had a role in improving the outcome of GIST patients with liver metastases.

Upregulated Vav2 in gastric cancer tissues promotes tumor invasion and metastasis.

Several studies have proved that Vav2 gene is associated with the carcinogenesis of some tumors, but the relationship between Vav2 gene and gastric cancer remains unclear. Purpose of this study is to detect the expression of Vav2 protein in gastric cancer tissues and to evaluate the clinical value of Vav2. Furthermore, both effect of Vav2 gene on invasion and metastasis of gastric cancer cells and its mechanism are investigated in vitro. Results showed that positive rate of Vav2 protein was significantly higher in gastric cancer tissues than in adjacent tissues and notably higher in metastatic lymph nodes than in gastric cancer tissues. Results of western blot were consistent with immunohistochemistry. Expression of Vav2 protein in gastric cancer tissues was related to degree of tumor differentiation, lymph node metastasis, and clinical stages. Inhibition of endogenous Vav2 in BGC823 cells led to significantly decreased cell activity, migration, and invasion ability in vitro, and expression of Rac1, MMP-2, and MMP-9 decreased, whereas expression of TIMP-1 increased. We concluded that Vav2 might promote invasion and metastasis of gastric cancer by regulating some invasion and metastasis-related genes.

Enhancement of Drug Sensitivity by Knockdown of HIF-1α in Gastric Carcinoma Cells.

In this study, the effects of hypoxia-inducible factor-1α (HIF-1α) on gastric carcinoma (GC) drug resistance through apoptosis-related genes are investigated. First, HIF-1α-specific siRNA was synthetized and transfected into drug-resistant GC cell line OCUM-2MD3/L-OHP. Then MTT assay was applied to test the inhibition rate of GC cells by 5-fluorouracil (5-FU) and oxaliplatin (L-OHP). After that, flow cytometry (FCM) was applied to measure apoptosis rate. qPCR and Western blot assay were employed to detect HIF-1α and apoptosis-related genes. Results showed that HIF-1α in OCUM-2MD3/L-OHP cells was higher than that in OCUM-2MD3 and gastric epithelial cells. After HIF-1α-siRNA transfection, inhibition rates of 5-FU and L-OHP to tumor cells increased significantly. FCM results showed that apoptosis rate of OCUM-2MD3/L-OHP cells increased significantly. After HIF-1α-siRNA transfection, survivin and Bcl-2 decreased, whereas Bax, caspase 3, and caspase 8 increased significantly. Results from this study seem to confirm that HIF-1α getting involved in GC drug resistance is possibly due to its regulation of some apoptosis-related genes. HIF-1α may be a potential target to reverse drug resistance of GC.

Inhibition of Vav3 gene can promote apoptosis of human gastric cancer cell line MGC803 by regulating ERK pathway.

Previous studies proved that Vav3 gene was overexpressed in cancers. However, the molecular mechanism of Vav3 in apoptosis still keeps unclear; therefore, the relationship between Vav3 gene and apoptosis of gastric cancer (GC) was explored in the present study. Vav3-siRNA was transfected into MGC803 cells, and then cell activity and apoptosis rate were tested with MTT and FCM; apoptosis-related genes and proteins in MAPK signaling pathway were also tested. Results showed that Vav3 was overexpressed in GC than in adjacent normal tissues (all P < 0.05), and expression of Vav3 was related to degree of histological differentiation, cancer invasion depth, and lymphatic metastasis (Χ (2) = 7.185, P = 0.007; Χ (2) = 18.654, P < 0.001; Χ (2) = 5.058, P = 0.025). Vav3 silencing inhibited activity of MGC803 cells, and apoptosis rate of cells was affected. Vav3-siRNA transfection led to changes of apoptosis-related genes such as Survivin, xIAP, Bcl-2, caspase-3, and Bax (all P < 0.01). After transfection, ratio of phosphorylation of ERK significantly reduced. We concluded that Vav3 inhibition can suppress cell activity and promote apoptosis by regulating the apoptosis-related genes through the ERK pathway.

Role of RNA-interference-induced zinc finger protein 139 suppression in gastric cancer cell sensitivity to chemotherapeutic agents.

Zinc finger proteins (ZNFs) are a class of proteins widely distributed in the human genome, which have been found to play a role in the regulation of gene transcription and the occurrence and development of gastric cancer (GC). ZNF139 was found to be associated with GC in our previous experiments. The present study aimed to analyse the differences in ZNF139 protein expression in SGC7901 GC cells and in situ grafted GC tumors in nude mice prior to and following RNA interference inhibition, and to investigate the mechanisms underlying ZNF139 involvement in the occurrence, development and chemosensitivity of GC. A ZNF139-targeted small interfering (si)RNA plasmid was constructed and transfected into the cancer cells and in situ grafted tumors. The MTT assay was used to investigate the alterations in chemosensitivity prior to and following transfection of siRNA-ZNF139. The two-dimensional difference gel electrophoresis and liquid chromatography-mass spectrometry techniques were used to identify the different protein points prior to and following siRNA-ZNF139 transfection. Western blot analysis was performed to confirm the identified proteins. In the siRNA-ZNF139 group, the growth of the cancer cells and in situ grafted tumors significantly decreased. However, the post-interference chemosensitivity to 5-fluorouracil, cisplatin and mitomycin C significantly increased. In the in vivo and in vitro experiments, the expression of pyridoxal kinase (PDXK) was upregulated, whereas the expression levels of annexin A2 (ANXA2) and fascin were downregulated following transfection. Western blot analysis confirmed the results for PDXK, ANXA2 and fascin by proteomics. Therefore, ZNF139 may participate in the occurrence, development and chemosensitivity of GC by promoting the expression of ANXA2 and fascin, while inhibiting the expression of PDXK.

HIF-1α Induces Multidrug Resistance in Gastric Cancer Cells by Inducing MiR-27a.

This study aimed to determine the correlation between HIF-1α and miR-27a expression and to evaluate the effect of inhibition of HIF-1α expression on miR-27a expression and drug resistance in gastric cancer (GC). In the present study, real time-PCR and Western blot were performed to detect the expression of HIF-1α in GC tissues and cell lines. Then, OCUM-2MD3/L-OHP cells were transfected with HIF-1α-siRNA, a miR-27a mimic or pcDNA-HIF-1α, and cell survival was determined via the MTT assay. The expression of HIF-1α, miR-27a, and MDR-related genes was measured via real time-PCR and Western blot. ChIP and dual luciferase activity assays were performed to assess the transcriptional regulation of HIF-1α and miR-27a. The results revealed that transfection with HIF-1α-siRNA markedly decreased the levels of miR-27a, resulting in dramatically enhanced inhibition of the proliferation rate of OCUM-2MD3/L-OHP cells. Compared to non-transfected cells, the survival rate was significantly reduced in the cells transfected with HIF-1α-siRNA after treatment with L-OHP. The cell survival rate was significantly increased in OCUM-2MD3/L-OHP cells transfected with the miR-27a mimic, whereas HIF-1α overexpression did not result in any clear change in cell survival. The results of the dual luciferase activity assay demonstrated that HIF-1α enhances the transcriptional activity of the miR27a promoter in cells transfected with a reporter plasmid containing the upstream promoter region of miR27a together with pcDNA-HIF-1α. ChIP analysis suggested that HIF-1α directly binds to the promoter region of miR27a. Inhibition of HIF-1α or miR27a expression decreased MDR1/P-gp, LRP, and Bcl-2 expression in OCUM-2MD3/L-OHP cells. Thus, we found that HIF-1α is closely associated with MDR in GC and that HIF-1α may suppress MDR1/P-gp, LRP and Bcl-2 expression by inhibiting miR-27a expression.

Comparative proteomics in gastric cancer cell line BGC823 after ZNF139 gene inhibited with RNA interference.

BACKGROUND/AIMS: Zinc finger protein 139 (ZNF139) gene is proved play an important role in gastric cancer. Aim of this study is to identify changes of proteins after ZNF139 gene was inhibited in gastric cancer cell line BGC823. METHODS: siRNA-specific ZNF139 was synthesized and transfected into BGC823; 2-D fluorescence difference gel electrophoresis (2-D DIGE) and liquid chromatography-mass spectrometry (LC-MS) were applied to screen, identify differentially expressed proteins, and function of these proteins was analyzed; Western blot method was applied to verify the identified proteins. RESULTS: ZNF139 expression in siRNA transfected cancer cell BGC823 decreased significantly. Results of 2-D DIGE showed eight differential protein spots, of which seven were identified with LC-MS, including switches associated protein 70, far upstream element binding protein 1, heat shock protein 60, annexin A7, small ubiquitin-like modifier 1 activating enzyme, chaperonin-containing tail-less complex protein 1 and annexin A2. These proteins were found to be associated with proliferation, apoptosis, invasion, metastasis, adhesion of gastric cancer cells with bioinformatic analysis. Western blot analysis confirmed that expressions of these proteins in BGC823 were consistent with the proteomic results. CONCLUSIONS: ZNF139 gene may influence the biological behavior of gastric cancer cells in many ways by regulating multiple proteins.

Expression of annexin A7 and its clinical significance in differentiation and metastasis of gastric carcinoma.

OBJECTIVE: To investigate the expression and clinical significance of annexin A7 in the differentiation and lymphatic metastasis of gastric cancer (GC). METHODS: The clinical and pathological data were recorded for analysis. Immunohistochemical staining and Western blot were performed to analyze the expression of ANXA 7 in primary GC tissues. Logistic regression analyses were conducted to evaluate the associations between annexin A7 expression levels and differentiations of GC. Analyses of the ROC were conducted to determine the cut-off value of the ratio of pixel density of annexin A7 for predicting lymphatic metastasis of GC. RESULTS: A total of 162 GC patients were enrolled in this study, and expression rate of annexin A7 was 65.4% in GC. The survival rate of patients with positive expression of annexin A7 was lower than that in patients with negative expression (P=0.000). The results of COX regression showed that the positive expression of annexin A7, submucosal confinement and pathological stage of GC were associated with poor clinical outcomes. The ratio of pixel density value of primary GC tissues with PN 1-3 lymphatic spread was significantly higher than those in tissues with PN 0 lymphatic spread (0.56±0.09 vs. 0.42±0.07, P < 0.05). ROC analysis showed a high area under the curve for the ratio of pixel density value of annexin A7 in primary GC tissues. At a cut-off level of > 0.505, the ratio of pixel density value of annexin A7 exhibited 76.7% sensitivity and 88.3% specificity for detecting lymphatic metastasis of GC. CONCLUSION: High annexin A7 expression is associated with poor differentiation in GC patients, and it may be a predictor for lymphatic metastasis of GC.

Regulatory mechanism of ZNF139 in multi-drug resistance of gastric cancer cells.

Our previous study found increased zinc finger protein 139 (ZNF139) expression in gastric cancer (GC) cells. Purpose of the study is to further clarify the role and mechanism of ZNF139 in multi-drug resistance (MDR) of GC cells. MTT assay, RT-PCR, Western blotting were employed to detect susceptibility of GC cells to chemotherapeutic agents (5-FU, L-OHP) in vitro, and expressions of ZNF139 and MDR associated genes MDR1/P-gp, MRP1, Bcl-2, Bax were also detected. siRNA specific to ZNF139 was transfected into MKN28 cells, then chemosensitivity of GC cells as well as changes of ZNF139 and MDR associated genes were detected. It's found the inhibition rate of 5-FU, L-OHP to well-differentiated GC tissues and cell line was lower than that in the poorly differentiated tissues and cell line; expressions of ZNF139 and MDR1/P-gp, MRP1 and Bcl-2 in well-differentiated GC tissues and cell line MKN28 were higher, while Bax expression was lower. After ZNF139-siRNA was transfected into MKN28, ZNF139 expression in GC cells was inhibited by 90%; inhibition rate of 5-FU, L-OHP to tumor cells increased, and expressions of MDR1/P-gp, MRP1 and Bcl-2 were down-regulated, while Bax was up-regulated. ZNF139 was involved in GC MDR by promoting expressions of MDR1/P-gp, MRP1 and Bcl-2 and inhibiting Bax simultaneously.

[Effect and mechanisms of TET on human gastric carcinoma cell line SGC7901 and SGC7901/ADR].

OBJECTIVE: To investigate the effect of tetrandrine (TET) on zinc finger protein 139 (ZNF139) and multidrug resistance (MDR) of human gastric carcinoma cell lines and possible mechanisms. METHODS: Cultured SGC7901 and SGC7901/ADR were treated with TET (0.5, 1.0, 1.5, 2.0, and 2.5 microg/mL), then inhibition rates were measured by MTT assay in vitro. The expressions of ZNF139, MRP-1, MDR1, and GST-pi were detected by RT-PCR. The correlation between ZNF139 and each multidrug resistance factor was analyzed using Spearman correlation analysis, and the coefficient correlation was calculated. RESULTS: The inhibition rate of TET (< or = 2.0 microg/mL) for SGC7901 and SGC7901/ADR was less than 10% with MTT assay. Expressions of ZNF139, MRP-1, MDR1, and GST-pi mRNA were higher in SGC7901/ADR than in SGC7901 (all P < 0.05). The expressions of ZNF139, MRP-1, MDR1, and GST--pi were down-regulated in SGC7901/ADR cells efficiently (all P < 0.01). Positive correlation existed between ZNF139 and MRP-1, ZNF139 and MDR1 before treated by TET in SGC7901/ADR, and this relationship also existed in SGC7901/ADR cells after treated by TET (all P < 0.05). CONCLUSION: TET could achieve MDR reversion in gastric cancer cells by down-regulating the expression of ZNF139, MRP-1, and MDR1.

Zinc finger protein 139 expression in gastric cancer and its clinical significance.

AIM: To investigate the expression of zinc finger protein 139 (ZNF139) in gastric cancer (GC), and to analyze its clinical significance. METHODS: A total of 108 patients who were diagnosed with GC and underwent surgery between January 2005 and March 2007 were enrolled in this study. Gastric tumor specimens and paired tumor-adjacent tissues were collected and paraffin-embedded, and the clinicopathologic characteristics and prognosis were recorded. The expression of ZNF139, Bcl-2, Bax, and caspase-3 were determined by immunohistochemistry, and apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling. SPSS 13.0 software was used for data processing and analyses, and significance was determined at P < 0.05. RESULTS: The expression of ZNF139 was stronger in tumors than in tumor-adjacent tissues (66.67% vs 44.44%; P < 0.01). Overexpression of ZNF139 correlated with tumor differentiation, invasion depth, clinical stage, lymphatic metastasis, and blood vessel invasion (all Ps < 0.05). Patients with overexpression of ZNF139 had a poorer prognosis (P < 0.01), and overexpression of ZNF139 was an independent factor for the prognosis of GC patients by a Cox survival analysis (P = 0.02). A negative relationship between ZNF139 and the apoptosis index was observed (r = -0.686; P < 0.01). The expression of Bcl-2 in GC was stronger than in tumor-adjacent tissues (66.67% vs 41.67%), whereas the expression levels of Bax and caspase-3 were lower in primary tumors (54.63% and 47.22%, respectively) than in tumor-adjacent tissues (73.15% and 73.15%, respectively) (all Ps < 0.05). The expression of ZNF139 negatively correlated with caspase-3 (r = -0.370; P < 0.01). The expressions of Bcl-2 and Bax were also negatively correlated (r = -0.231; P = 0.02). The expressions of caspase-3 and Bax protein were positively correlated (r = 0.217; P = 0.024). CONCLUSION: ZNF139 is related to clinicopathologic characteristics and prognosis of GC. Furthermore, it is overexpressed and involved in apoptosis in GC tissues by regulating caspase-3.

A new bisphosphonate derivative, CP, induces gastric cancer cell apoptosis via activation of the ERK1/2 signaling pathway.

AIM: To investigate the effects of a new derivative of bisphosphonates, [2-(6-aminopurine-9-yl)-1-hydroxy-phosphine acyl ethyl] phosphonic acid (CP), on human gastric cancer. METHODS: Human gastric cancer cell lines (SGC-7901, BGC-823, MKN-45, and MKN-28) and human colon carcinoma cell lines (LoVo and HT-29) were tested. Cell growth was determined using the MTT assay. Flow cytometry, Western blot, caspase activity assay and siRNA transfection were used to examine the mechanisms of anticancer action. Female BALB/c nude mice were implanted with SGC-7901 cells. From d6 after inoculation, the animals were injected with CP (200 µg/kg, ip) or vehicle daily for 24 d. RESULTS: CP suppressed the growth of the 6 human cancer cell lines with similar IC50 values (3239 µmol/L). In SGC-7901 cells, CP arrested cell cycle progression at the G2/M phase. The compound activated caspase-9, increased the expression of pro-apoptotic proteins Bax and Bad, decreased the expression of anti-apoptotic protein Bcl-2. Furthermore, the compound selectively activated ERK1/2 without affecting JNK and p38 in SGC-7901 cells. Treatment of SGC-7901 cells with the specific ERK1/2 inhibitor PD98059 or ERK1/2 siRNA hampered CP-mediated apoptosis. In the human gastric cancer xenograft nude mouse model, chronic administration of CP significantly retarded the tumor growth. CONCLUSION: CP is a broad-spectrum inhibitor of human carcinoma cells in vitro, and it also exerts significant inhibition on gastric cancer cell growth in vivo. CP induces human gastric cancer apoptosis via activation of the ERK1/2 signaling pathway.

Technique appraisement of comparative proteomics and screening of differentiation-related protein in gastric carcinoma.

BACKGROUND/AIMS: Different differentiations of cancer have resulted in its unique biological characteristics. We screen and appraise differentially expressed proteins in different differentiated gastric adenocarcinoma with comparative proteomics technology in order to find regulatory factors of tumor differentiation related and finally reach the purpose of tumor differentiation reversal. METHODOLOGY: With two-dimensional fluorescence difference gel electrophoresis (2-D DIGE) and liquid chromatography in conjunction with tandem mass spectrometry (LC­MS/MS), the differentially expressed proteins from 8 patients with different differentiated gastric adenocarcinoma were identified and some factors identified were verified with application of QPCR and Western blot techniques. RESULTS: Significant differences in 35 protein spots were found and 48 kinds of proteins were identified. Other than structural proteins and non-specific protein, six possible proteins associated with tumor differentiation were determined - the serine protease inhibitor B1 (serine protease inhibitor, clade B, member 1, SERPINB1), calcium-phospholipid binding protein III (annexin A3), transcription factor Nm23-H1, adenine phosphoribosyl-transferase enzyme APRT (Adenine Phosphoribosyltransferase in APO and AMP), glutathione S-transferase P1-1 (GST-π-1), antimicrobial peptides Dermcidin-lL. The identified SERPINB1, annexin A3, Nm23-H1 and APRT were verified, confirming the expression of these factors was in line with proteomics identification. CONCLUSIONS: Protein expression in different differentiated gastric adenocarcinoma was varied.

Analysis of lymph node dissection range-related factors for early gastric cancer operation.

BACKGROUND/AIMS: The purpose of comprehensive treatment for early gastric cancer (EGC) is curing tumor, prevention of recurrence or metastasis. The aim of the present study was to analyze the clinical pathological characteristics of EGC, and to find out factors which influence lymph node metastasis. METHODOLOGY: Records of 417 patients with EGC who underwent surgery from January 1996 to December 2006 were collected. The information including general characteristics, tumor relevant factors, surgical complications, clinical manifestations and pathological features, were evaluated. RESULTS: EGC accounted for 6.03% of total gastric cancer (GC) cases. In EGC subjects, mucosal cancer and sub-mucosal cancer accounted for 55.2% and 44.8%, respectively; 11.5% (48/417) of patients were found with positive lymph nodes metastasis, the incidence of lymph node metastasis was 5.64% (168/2979); 6 cases were found with liver metastasis; 96.64% of patients undertook radical surgical treatment; 5 cases with positive upper incisal margin (1.2%). Logistic regression analysis showed that multiple original tumors, lesions of over 2cm, tumor invasion to the submucosa, poor differentiation, and vascular tumor thrombus, were independent risk factors for lymph node metastasis in EGC. CONCLUSIONS: The risk factors of lymph node metastasis should be noticed and evaluated in EGC treatment.