A study on FAP expression and correlation with MVD in the stroma of gastric carcinoma

Abstract

Objective To investigate the expression of fibroblast activation protein (FAP) in human gastric carcinoma (GC) and the relationship between FAP expression and microvessel density ( MVD). Methods Human GC specimens from one hundred sixty-two patients were available for study. Nude mice model was subcutaneously transplanted with human gastric carcinoma SGC-7901 cells. The expression of FAP and CD34 in gastric carcinoma tissue was detected by immunohistochemistry. Results FAP expresses in stromal fibroblasts in 90.74% (147 cases) patients with GC, while carcinoma cells and normal gastric tissues are negatively for FAP. In gastric carcinoma, FAP expression and MVD associate with tumor invasion(χ2=51. 882,P <0.01; χ2 = 46.383,P<0.01), differentiation(χ2=40. 193,P<0. 01;χ2 =21. 617,P <0.01) and lymph node metastasis(χ2=24. 232,P <0.01 ;χ2 =13. 393,P<0.01). In fifteen cases of tumor tissue from nude mice transplanted subcutaneously with human gastric carcinoma SGC-7901 cells, all tumors show different degrees of FAP expression. MVD significantly correlates with FAP intensity in both human gastric carcinoma(χ2=97. 710,P < 0. 01) and mouse tumor tissue(χ2= 11. 100,P <0. 01). MVD increases in samples with increased FAP expression. Conclusion In GC, FAP expression correlates with the invasion and metastasis. FAP may promote tumor growth, invasion and metastasis by facilitating tumor angiogenesis. Key words: Gastric carcinoma; FAP; Angiogenesis; SGC-7901; Nude mice