Objective: To detect the expressions of ERCC2 and ERCC4 genes in osteosarcoma (OS) and peripheral blood lymphocyte (PBL), and their relationship with the prognosis to provide potential markers for evaluating the chemotherapeutic effect and prognosis of OS.
Methods: Between Jan. 2006 and Nov. 2006, 26 OS patients were chosen for this study. A small quantity of specimens were obtained in the open biopsy before chemotherapy, as well as 5 mL venous blood to separate PBLs. All of the patients received chemotherapy preoperatively and then operation. After the operation, the resected tumor specimens were examined completely for tumor necrosis rates which were related to chemotherapy. The tumor necrosis rates were classified into two groups, high tumor necrosis (TN) group and low TN group. The expressions of ERCC2 mRNA and ERCC4 mRNA of OS cells in open biopsy specimens were analysed by real time PCR, and so were those of the PBLs from venous blood. The correlations of mRNA expression level of the two genes both in OS cells and in PBLs with different tumor necrosis groups were analysed,respectively. The correlations of ERCC2 mRNA in OS and PBLs were analyzed, and so were those of ERCC4 mRNA level. And their associations with clinical features, including sex, age, tumor volume, tumor stages, alkaline phosphatase (AKP) and lactate dehydro-genase (LDH) were analyzed , respectively. All of the data were processed statistically with SPSS software.
Results: The expression levels of ERCC4 mRNA in OS cells of high TN group (6.29+/-1.20) were significantly higher compared to those of the low TN group (5.14+/-1.16), P=0.023. Also the expression levels of ERCC4 mRNA in PBLs of high TN group (5.59+/-1.15) were significantly higher compared to those of the low TN group (4.52+/-1.20), P=0.032. And there was a positive correlation between ERCC4 mRNA levels in OS and in PBLs (r=0.768, P<0.01). ERCC2 mRNA only in OS cells of high TN group (3.49+/-1.14) were significantly higher compared to those of the low TN group (2.33+/-1.31), P=0.029. ERC4 expression in OS was significantly associated with age and ERCC2 expression in OS was significantly associated with AKP level, respectively.
Conclusion: The expressions of ERCC4 mRNA in OS cells or PBLs and ERCC2 mRNA were correlated with chemotherapeutic effect of osteosarcoma. The detection of the genes above may be useful for evaluating prognosis.