Expression And Clinical Significance Of SPARC MRNA And Protein, MMP-9 Protein In Gastric Carcinoma

Objective To investigate the expression of SPARC mRNA and protein, MMP-9 protein in human gastric carcinoma and their relationship with clinical pathological features. To explore their roles in carcinogenesis and progression of gastric carcinoma and to evaluate their clinicopathologic significances. Methods Immunohistochemical staining (S-P method) for SPARC protein and MMP-9 protein were performed in 108 cases of gastric carcinoma and 89 cases of normal gastric tissues 5cm distant from tumor. In situ hybridization (ISH) for SPARC mRNA was examined in 108 cases of gastric carcinoma and 34 cases of normal gastric tissues 5cm distant from tumor. Results : [1] The SPARC mRNA expression was detected mainly in the stromal cells and little in carcinoma cells. The positive rate of SPARC mRNA was higher in human gastric carcinoma (80.6%),compared to normal gastric mucosa (2.9%).The difference was significant (P<0.01). The expression of SPARC mRNA was unrelated to the biological speciality and clinical pathologic factors of gastric carcinoma(P>0.05).[2] The SPARC protein expression was detected mainly in the stromal cells and little in cancer cells. The positive rate of SPARC protein was higher in human gastric carcinoma (88.0%),compared to normal gastric mucosa (14.1%).The difference was significant (P<0.01). The stromal positive expression rate of SPARC was significantly related with lymph node metastasis and clinical stage(P<0.01),but it did not correlate with sex,age,tumor size ,the depth of tumor invasion and distant metastasis(P>0.05).[3] A positive correlation was found between the expression of SPARC mRNA and SPARC protein(r = 0.518, P=0.039).[4] The positive rate of MMP-9 in gastric carcinoma were higher than in normal gastric mucosa(P<0.01).There was a difference of the expression rate of MMP-9 among papillary adenocarcinoma, tubular adenocarcinoma, poor differentiated adenocarcinoma and mucoid carcinoma(P<0.01). The positive expression rate of MMP-9 was significantly related with the depth of tumor invasion , lymph node metastasis and clinical stage(P<0.05),but it did not correlate with sex,age,tumor size and distant metastasi(sP>0.05).[5] A positive correlation was found between the expression of SPARC and MMP-9 protein(r = 0.561, P=0.000). Conclusions [1] In gastric carcinoma,stromal SPARC protein expression is regulated at the transcriptional level .The elevation of SPARC protein expression is correspondingly the result of elevation of transcriptional level. [2] SPARC and MMP-9 have high expression rate in tissue of gastric carcinoma, which indicates that SPARC and MMP-9 are closely related to the invation and metastasis of gastric carcinoma. SPARC and MMP-9 are considered as important guidelines in estimating of biological speciality of gastric carcinoma.