Original Article Grb7 gene amplification and protein expression by FISH and IHC in ovarian cancer

Objective: Overexpression of growth factor receptor-bound protein 7 (Grb7) has been found in numerous human cancers. The aim of this study was to evaluate the correlation between Grb7 gene amplification and protein expression in ovarian cancer (OC). Methods: We use Tissue Microarray (TMA) respectively to detect the gene ampli- fication and protein expression of Grb7 in 90 cases OC and 10 control specimens of normal ovarian tissues by IHC and FISH. Results: The Grb7 protein expression by IHC analysis was observed in 52/90 (57.8%) OC with 3 cases (3.3%) scored 3 + and 9 cases (10%) scored 2 + Grb7 gene amplification by FISH analysis was successfully detectable in 6 specimens with a positive rate of 6.8% (6/88) in which immunostaining 3 + , 2 + and negative (1 + /0) expressions of Grb7 were 100.0% (3/3), 11.1% (1/9) and 2.6% (2/76), respectively. Our data exhibited that the IHC and FISH results had a good consistency between Grb7 gene amplification and Grb7 protein expression (Kappa = 0.651, P < 0.001). Both the results of IHC and FISH revealed that Grb7 did not seem to have a role in OC clinicopathology. Conclusion: There is a close relationship between Grb7 gene amplification and GRB7 protein overexpression in hu - man OC. IHC might have limited diagnostic value especially in these tumors and especially in characterizing geneti- cally diverse borderline cases, FISH could be superior to IHC.