MMP-9 Gene And Peripheral Protein Related Research In Gastric Carcinoma

Objective:To investigate causality between MMP-9 gene expression and preoperative peripheralprotein level in gastric carcinoma patients. To evaluate the MMP-9 expression difference amongtumor tissue,remote tissue,normal control tissue. To find out the MMP-9 expression differencein preoperative peripheral serum,gastric juice between gastric cancer group and control group.And observe the relationship between matrix metalloproteinase expression and gastric tumorclinical pathological features.Methods:Collected the samples from 45 cases of gastric carcinoma patients during the year 2005from June to December in SHANTOU university medical college, the first affiliated hospitalsurgery departments. Alter proper disposal, we detected the samples and analyzed the data.1) Took the peripheral venous blood from gastric cancer patients and separated outserum.Detected MMP-9 protein in gastric tumor patients preoperative serum by ELISA method.2) Drawed the preoperative gastric juice by nasogastric tube from gastric tumor patients. Aftergastric juice neutralization and centrifugalization, detected MMP-9 protein level in gastrictumor patients preoperative gastric juice by ELISA method.3) Freezed and saved the fresh gasric tumor tissue and corresponding remote gastric tissue, andextracted the gross RNA from tissue with TRIZOL, investigated MMP-9 gene expressionby semi-RT-PCR. The MMP-9 gene amplification product was sent to sequencing andanalysis.4) Evaluated MMP-9 protein expression in gastric tumor tissue, remote gastric tissue, normalcontrol tissue by IHC method.Result:1) Matrix metalloproteinases-9 mRNA had expressed in 95.6%(43/45) gastric carcinomapatients. The average grey value was 0.61±0.6 in cancer group detected by Semi-quantitativereverse transcriptase polymerase chain reaction. Comparing with the corresponding remotegastric tissue group, they were 40% (18/45) cases being amplified and the average greyvalue was 0.44±0.44. The difference between two groups was not statistically significant,but both level of MMP-9 mRNA were statistically higher than normal gastric tissue group0.03±0.06(P＜0.01).2) Gastric cancer group MMP-9 protein expression positive rate was 86.7%(39/45), and thepositive rate in the corresponding remote gastric tissue group was 26.7% (12/45). Thedifference between two groups was statistically significant(P＜0.01). Comparing with thepositive rate 10% (1/10)of normal control group, cancer group was statistically higher thanthat(P＜0.01). Protein expression positive rate was significantly related with cancer invasiondegree(P＜0.05).3) Protein could be detected in both gastric cancer group and control group in preoperativeserum samples, and the average MMP-9 protein level in the cancer group was406.03±257.18 ng/ml which was significant higher than control group 167.35±54.04ng/ml(P＜0.01). The protein level in advanced TNM staging and positive lymph nodesmetastasis patients were significant higher than that in early TNM staging and negativelymph nodes metastasis patients(P＜0.01).4) MMP-9 protein in gastric juice could be detected in 46.7%(21/45)cases from cancer group,while there were only 10%(1/10) cases in control group. The average of MMP-9 protein level in the preoperative gastric juice of cancer group was 77.59±191.97 ng/ml which wassignificant higher than normal control group 0.81±2.39 ng/ml(P＜0.01). The protein levelwere significantly related with tumor invasion degree,tumor TNM staging and lymph nodesmetastasis(P＜0.01).5) Correlation analysis between MMP-9 gene expression and preoperative peripheral proteinin serum and gastric juice showed MMP-9 gene expression significantly correlated withprotein expression in gastric juice(r=0.366,P＜0.05), but not the protein in serum(P＞0.05).6) MMP-9 expression is not significantly different between tumor history positive and negativegroups(P＞0.05); MMP-9 is not correlated with blood style in cancer group(P＞0.05).Conclusion:1) The MMP-9 gene may abnormally active and express in gastric tumor patients, and it wasvaluable to detect MMP-9 gene expression by semi-RT-PCR for tumor diagnosis.2) It was valuable to detect the MMP-9 protein expression by IHC in tumor tissue for tumordiagnosis and malignancy assessment.3) Detection of protein level in preoperative serum was meaningful for gastric cancerprogression evaluation and individual clinical therapy project making.4) Detection of protein level in preoperative gastric juice was meaningful for gastric cancerprogression evaluation and individual clinical therapy project making and it supplied ahurtless method to evaluate clinic gastric tumor progression.5) The protein expression in gastric juice may indicate the extent of gene expression in cancertissue, and it supplied a indirect way to estimate MMP-9 gene expression in gastric cancertissue.6) Tumor history maybe do nothing with the MMP-9 expression in gastric carcinoma; Bloodstyle may be not involved in MMP-9 expression in gastric cancer group.