| Objective: According to the statistics, gastric cancer ranked No.4 in the world. Each year, there are about 90 million people attacked by gastric cancer, and about seventy hundred thousand people died. Our country is high the riskarea. The number of annual new gastric cancer patients in our country accounting for 42 percents of the world. Patients with early gastric cancer have no obvious signs and symptoms, most of them have been found in advanced stage, even more later. Surgery combine with chemotherapy is the most common way. The reasonable chemotherapy can improve curative effect, and it can prolong the lifetime. Multiple drug resistance is the key factor influencing the prognosis. MDR include natural MDR and acquired MDR. Mechanism of MDR of tumor tissue is vital complicate, it involves multiple factors and multiple steps. Molecular mechanisms involve many aspects, such as abnormal expression of oncogene, antioncogene and multidrug resistanceassociated proteins and so on. By further studying the resistant proteins of Multidrug resistance,P-glycoprotein, multidrugresistance protein1,thymidylate synthase, glutathione-S-transferase and related molecular mechanisms are the keys to reverse the chemotherapy failure.Therefore, the search for new drug resistant gastric cancer-associaed proteins are important. Vav1 is a protooncogene, it has a guanine nucleotide exchange factor(GEF) activity. It belongs to the family of a Db1 and plays an important role in the process of malignant tumors invasion and metastasis. It is a sign of poor prognosis in patients with malignant tumors. The studies had found that Vav1 could increase the transcriptional activity of Bcl-2 who was anti-apoptotic gene, so that the tumor cells avoided apoptosis. The GEF activity of Vav1 was necessary for Bcl-2.Bcl-2 could increase the resistance of tumor cells to anticancer drugs through coordinated with P-gp.Thus, it suggested that there was a closer relationship between Vav1 and MDR.In this article, we selected 42 samples of advanced patients with gastric carcinoma and metastatic lymph node of every patient, through adopted the method of realtime fluorescence quantitative PCR to detect gene expression of Vav1 variation and relationship between gastric carcinoma and metastatic lymph nodes. By using S-P immunohisto-chemical technique detected the protein of vav1, MDR1/P-gp, MRP1, TS, GST-? in gastric carcinoma and metastatic lymph nodes, analyzed the relationship between vav1 protein and resistant protein in gastric carcinoma and metastatic lymph nodes. Drug chemosensitivity of 5-FU, VP-16, PTX, CDDP, MTX to different cancer cells were measured by MTT assay. To explore relationship and significance between Vav1 and MDR.Methods:In this study, we collected 42 paitients of fresh gastric carcinoma tissues and relevant metastatic lymph nodes, which were fixed by formaldehyde. By using qPCR to evaluate the mRNA expression of vav1 and using S-P immunohisto-chemical technique detected the protein of Vav1, MDR1/P-gp, MRP1, TS, GST-? in gastric carcinoma and metastatic lymph nodes. By making correlation analysis to clear Vav1 with resistant protein relationship and significance in two different cancer tissues. Drug chemosensitivity of five groups of cells for 5-FU, VP-16, PTX, CDDP, MTX to gastric carcinoma and metastatic lymph node cells were measured by MTT assay. SPSS 21.0 was applyed to analyse the obtained data. Paired-samples t-test was used to analyse comparison of the measurement data. Chi square test was used to analyse enumeration data. Spearman correlative coefficient was used to calculate correlation analysis of the double variable. The statistic significance was assessed as a probability value of P<0.05 in all experiments.Results:1 The mRNA and protein expression level of vav1 compared between gastric carcinoma and metastatic lymph nodes and correlation.The protein expression level of Vav1 in metastatic lymph nodes was higher than in gastric carcinoma(?~2=5.927, P=0.015), and they had obvious correlation between the two different cancer tissues(r=0.359, P=0.019). The mRNA expression level of Vav1 in metastatic lymph nodes was higher than that in gastric carcinoma(0.379±0.233 vs 0.123±0.081, t=7.818,P=0.000), and they had obvious correlation between the two fifferent cancer tissues(r=0.418, P=0.006).2 Comparison between the protein expression levels of MDR1/P-gp, TS, MRP1, GST-? in gastric carcinoma and metastatic lymph nodes and correlation.The protein expression levels of MDR1/P-gp, TS, MRP1, GST-? in metastatic lymph nodes were higher than that in gastric carcinoma(?~2=5.974, ?~2=7.683,?~2=4.421,?~2=4.266, P=0.015, P=0.006, P=0.035, P=0.039).The expression levels of MDR1/P-gp, MRP1, GST-? had obvious correlation between gastric carcinoma and metastatic lymph nodes(r=0.380, r=0.336, r=0.311, P=0.013, P=0.030, P=0.045). The protein expression level of TS had no obvious correlation between gastric carcinoma and metastatic lymph nodes(r=0.28, P=0.072).3 The correlation between expression levels of Vav1, MDR1/P-gp, TS, MRP1 and GST-? in gastric carcinoma and metastatic lymph nodes.There were positive correlation between the protein expression levels of Vav1, MDR1/P-gp, TS, MRP1, GST-? in gastric carcinoma(r=0.378, r=0.440, r=0.437, r=0.348, P=0.014, P=0.004, P=0.004, P=0.024).There were positive correlation between the protein expression levels of Vav1, MDR1/P-gp, MRP1 in metastatic lymph nodes(r=0.365, r=0.355, P=0.017, P=0.030). And there were no obvious correlation between the protein expression of Vav1,TS, GST-? in metastatic lymph nodes(r=0.229, r=0.023, P=0.136, P=0.883).4 Comparison between expression of 5 kinds of chemotherapy and chemosensitivities in gastric carcinoma and metastatic lymph node cellsThe inhibition rates of metastatic lymph node cells for VP-16 were lower than those of gastric carcinoma(t=-2.28, P=0.025). However,there was no significant correlativity of 5-FU, PTX, CDDP, MTX between gastric carcinoma and metastatic lymph node cells(t=-1.23, t=-0.94, t=1.06, t=0.69, P=0.223, P=0.352, P=0.291, P=0.490).5 Relationship between expression of Vav1, multidrug resistance associat-ed factors and and chemossensitivities in two different gastric carcinoma cells.In PT, the inhibition rates of Vav1 strong expression group for 5-FU and PTX were much lower than the weak group(t=2.34, t=2.14, P=0.024, P=0.038). The inhibition rates of P-gp strong expression group for 5-FU was much lower than those in weak group(t=2.71, P=0.010). The inhibition rates of TS strong expression group for 5-FU, CDDP were much lower than those in weak group(t=4.40, t=2.19, P=0.000, P=0.019). There were lower inhibition rates in MRP1 strong expression group for 5-FU, PTX, CDDP than those in weak group(t=2.12, t=2.09, t=4.26, P=0.040, P=0.043, P=0.000). The inhibition rat-es of GST-? strong expression group for 5-FU, PTX, CDDP were much lower than those in weak group(t=2.17, t=2.48, t=2.13, P=0.036, P=0.017, P=0.040).In LNMs,the inhibition rates of vav1 weak group for 5-FU, CDDP were significantly much higher than those in strong group(t=2.10, t=2.37, P=0.042, P=0.023). The inhibition rates of P-gp weak expression group for 5-FU, PTX were much hi-gher than those in strong group(t=2.34, t=2.05, t=2.11, P=0.025, P=0.047, P=0.041). There was significantly much higher inhibition rates in MRP1 weak expression group for 5-FU than those in strong group(t=3.85, P=0.000). The inhibiton rates for CDDP was significantly much higher in weak group than those in strong group(t=3.16, P=0.003).Conclusion:1 The mRNA and protein expression level of Vav1 was higher in metastatic lymph nodes than that in gastric carcinoma. It showed that they had heterogeneity between gastric cancer tissues and metastasis lymph nodes. This result was considered that Vav1 participated in the process of the gastric cancer transfer. It was an important factor in the development of gastric cancer.2 The protein expression levels of MDR1/P-gp, TS, MRP1, GST-? in metastatic lymph nodes were significantly higher than that in gastric carcinoma. These showed that the four types of drug-resistant proteins had heterogeneity between gastric cancer tissues and metastasis lymph nodes. it prompted that metastasis nodes had stronger resistance and stronger progress trend.3 There were positive correlation between the protein expression levels of Vav1, MDR1/P-gp, TS,MRP1, GST-? in gastric carcinoma,and that between expression of Vav1 with TS, GST-? in metastatic lymph nodes. These prompted that vav1 participated in gastric cancer tissue invasion and metastasis in disease progression and drug resistance of gastric cancer had a cross molecular network, Or through one of regulatory mechanisms promote the progress of gastric cancer.4 The result of chemosensitivity experiment displayed that the susceptibility were different to 5-FU,VP-16, PTX, CDDP, MTX in gastric primary tumor and metastatic lymph nodes cells.It prompted that Hetergeneity of chemosensitivity of gastric cells changed in transfer process.They couldn't accord to gastric cancer drug resistance results to infer the drug susceptibility of metastatic lymph nodes comprehensive and accurately.5 The susceptibility were different to 5-FU, VP-16, PTX, CDDP, MTX in gastric primary tumor and metastatic lymph nodes cells.It showed thatHetergeneity of chemosensitivity of gastric cells have changed.Any MDRrelated factors reflect the primary gastric cancer or metastases of drug resistance were not comprehensive. The susceptibility of expression of Vav1 in gastric carcinoma in metastatic lymph nodes droped to 5-FU. The susceptibility of expression of Vav1 in metastatic lymph nodes droped to CDDP. It showed that Vav1 took part in MDR of gastric carcinoma, It could predicte MDR. But the drug resistance changed during the transfer.The susceptibility were no significant different to VP-16, CDDP, MTX. It prompted that Vav1 was just a factor in complex networks of gastric cancer MDR. |
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