Search

Objective: To investigate the expression of protein peak (3144 m/z) in serum and of its association with clinical pathological characteristics and prognosis in patients with gastric cancer., Methods: Three hundred and twenty seven pathologically confirmed gastric cancer patients were recruited from February 2006 to October 2008 in the Zhejiang Cancer Hospital. SELDI-TOF-MS was employed to detect the expression of protein peak (3144 m/z) in preoperative serum., Results: The positive rate of 3144 m/z protein peak was 33.9% (111/327), significantly higher than that of CEA (21.1%,69/327), and the difference was statistically significant (P<0.01). The positive rate of combined detection of protein peak (3144 m/z)and CEA was 45.6% (149/327). The expression of protein peak (3144 m/z) was associated with clinical staging (P<0.01), nervous invasion (P<0.01), tumor size (P<0.01), vascular invasion (P<0.05), lymph node metastasis (P<0.05), expression of CEA (P<0.05), and depth of infiltration (P<0.05). Significant difference was observed in 3-year survival rate between the patients with protein peak and patients without protein peak (44.7% vs. 64.4%, P<0.01). However, 3144 m/z protein peak was not an independent prognostic factor on multivariate Cox regression analysis (P=0.057)., Conclusion: Protein peak (3144 m/z) may be used as a diagnostic or prognostic marker of gastric cancer.

Objectives: To identify serum biomarkers associated with early gastric cancer., Methods: Serum proteins or peptides were purified with weak cation exchange magnetic beads in 433 patients with gastric cancer and 120 healthy subjects. Distinct peaks were selected using Biomarker Wizard software. The area under receiver operating characteristic curve(AUC) was generated to analyze discrimination capability of peaks between gastric cancers and health people., Results: Thirteen distinct peaks were identified between 42 gastric cancer and 42 health people matched by age and gender(P<0.001). There were 5 peaks (2745, 2768, 6629, 3402, and 6436 m/z) with AUC greater than 0.8. Peak of 6629 m/z was identified to be transthyretin. The sensitivity and specificity of 6629 m/z were 65.5% and 92.0%. The sensitivity of 6629 m/z was 59.4% in I(A gastric cancer., Conclusion: Transthyretin precursor may be of value in the early diagnosis of gastric cancer.

Objective: To investigate the expression of multidrug resistance (MDR) gene-associated proteins (MRP) in gastric carcinoma, and their effects on the postoperative adjuvant chemotherapy and the prognosis of patients., Methods: The expressions of ToPo II, MRP, GST-pi in 99 patients with gastric carcinoma were detected by immunohistochemistry. The expression and its relationship to the pathological data were analyzed. The positive expression of MRP and GST-pi, and the negative expression of ToPo II were considered as risk factors. Patients were divided into two groups: a high risk drug-resistant group (2-3 risk factors) and the low risk drug-resistant group (0-1 risk factors). Postoperative recurrence, survival rate, and efficacy of adjuvant chemotherapy were compared between two groups., Results: The positive rate of ToPo II was 74.7%, and the expression was associated with types and differentiation of the tumor. The positive rate of GST-pi was 49.5%, and the expression was related to the gender and the differentiation. The positive rate of MRP was 40.4%, and there was no relationship between the MRP expression and the pathological finding. There were no significant differences in the recurrence, time to recurrence, and the 5-year survival rate between the positive and negative group of the three proteins (P>0.05). Recurrence was found in 25 cases(55.6%) in the high risk drug-resistant group and the mean time to recurrence was (15.2+/-8.1) months. The time to recurrence was shorter in the low risk drug-resistant group [(21.3+/-11.1) months, P<0.05] , but there was no significant difference in the recurrence rate between two groups (P>0.05). The 5-year survival rate of the high risk drug-resistant group and the low risk drug-resistant group was 44.4% and 55.6% (P>0.05). The 5-year survival rates of patients with or without chemotherapy in the high risk drug-resistant group were 45.8% and 42.9% (P>0.05). The 5-year survival rates of patients with or without chemotherapy in the low risk drug-resistant group were 70.4% and 40.7%. The survival rate of patients with chemotherapy was higher than that of the patients without chemotherapy (P<0.05)., Conclusions: The expression of ToPo II, MRP and GST-pi is associated with the efficacy of postoperative adjuvant chemotherapy. Chemotherapy appears to be more beneficial to patients with low risk drug-resistance.

Objective: To screen the carcinogenesis associated genes in gastric carcinoma by gene chip., Methods: U133A (Affymetrix Santa Clara, CA) gene chip was used to detect differentially expressed genes in tumor tissues, paratumor mucosa and normal mucosa. Bioinformatics was used to analyze the screened results., Results: A total of 150 genes were detected with a difference of expression levels more than 3 times in paratumor mucosa compared with normal gastric mucosa, 130 of which were up-regulated and 20 down-regulated. According to the function classifications of the differentially expressed genes, the most common ones were enzyme and enzyme regulon activity associated genes(28, 18.7% ). The frequencies of nuclei acid binding activity associated genes,signal transduction associated genes and protein binding associated genes were 11.3%, 10%, and 8.7% respectively. Seventy-one differentially expressed genes were detected both in tumor tissues and paratumor mucosa compared with normal mucosa, 61 of which were up-regulated and 10 down-regulated. Among these 71 genes,e leven genes were localized on chromosome 19, 6 on chromosome 1, 2, 16, 17 respectively. No abnormal differentially expressed gene were detected on chromosome 5, 14, 22 and Y., Conclusions: These 71 genes differentially expressed both in tumor tissues and paratumor mucosa may be associated with carcinogenesis of gastric carcinoma. The four kinds of genes associated with enzyme and enzyme regulon activity, nuclei acid binding activity, signal transduction, and protein binding should be the main genes for the study of carcinogenesis in gastric carcinoma.

Objective: To study the difference of gene expression profiles in gastric cancer (T), pericancerous mucosa (P) and the gastric mucosa from distant cutting margin (C), and to screen an associated novel gene in early gastric carcinogenesis by oligonucleotide microarray., Methods: U133A (Affymetrix, Santa Clara, CA) gene chip was used to detect the gene expression profile difference in T, P and C, respectively. Bioinformatics was used to analyze the detected results., Results: When gastric cancer was compared with normal gastric mucosa, 766 genes were found,with a difference of more than four times in expression levels, including 530 up-regulated [Signal Log Ratio (SLR) > 2], and 236 down-regulated (SLR< -2). When P was compared with C, 64 genes were found, with a difference of more than four times in expression levels, including 50 up-regulated (SLR > 2), and 14 down-regulated (SLR< -2). Compared with C, a total of 143 genes with a difference of more than four times in expression levels both in T and P tissues. Of the 143 genes, 108 were up-regulated (SLR > 2), and 35 were down-regulated (SLR< -2)., Conclusions: Gene chip can reveal 143 same genes both in pericancerous mucosa and gastric mucosa. These genes may be related to the carcinogenesis and development of early gastric cancer.