We asked if differences in GILZ expression levels are related to the expression of two markers, the proliferation marker Ki 67 used in routine diagnostics and p AKT used to characterize malignant ovarian tumors. Hyperactivation of AKT is frequently observed in ovarian neoplasms and is related to the control of cell prolifera tion in EOC. Immunoreactivity of GILZ, Ki 67 and p AKT was measured find FAQ on serial sections of EOC. GILZ and Ki 67 immunostainings were scored on a seven point scale based on the staining intensity and the extent of staining. GILZ and Ki 67 expression scores were significantly correlated in the entire cohort. They were still correlated in serous carcinoma and non serous carcinoma as well. The expres sion of p AKT in tumor Inhibitors,Modulators,Libraries cells was mostly cytoplasmic, although some nuclear staining was also detected.

Inhibitors,Modulators,Libraries Both nuclear and cytoplasmic staining patterns were considered Inhibitors,Modulators,Libraries to assess p AKT immunoreactivity, scored as high or low. GILZ expression scores were significantly higher in p AKThigh specimens. After applying a single cut off on the entire cohort for identification of GILZhigh and GILZlow cases, we found that high GILZ Inhibitors,Modulators,Libraries scores are associated with higher p AKT staining and Ki 67 indexes. In contrast, age at diagnosis and distribution of histologi cal subtypes did not differ between the two groups. All these observations suggest that GILZ expression may regulate cell proliferation and AKT phosphorylation Inhibitors,Modulators,Libraries in EOC. To assess this hypothesis and to provide further bio logical evidence to support immunohistochemical data, we performed in vitro experiments using the BG 1 cell line as a cellular model.

Overexpression of GILZ increases proliferation and AKT phosphorylation in BG 1 cells To study the effect of GILZ on cell proliferation in epithe lial ovarian cancer, we generated BG 1 clones that stably and strongly express GILZ. As a control BG 1 cells were stably transfected with an empty vector. pGILZ and CTRL excellent validation clones were randomly selected for fur ther experiments. The GILZ protein content was signifi cantly higher in pGILZ clones than CTRL clones. We then compared their spontaneous cell prolifera tion it was significantly higher in pGILZ clones. To confirm that GILZ overexpression increased the proliferation rate, CTRL and pGILZ clones were seeded at equal densities, and viable cells were counted over a 4 day period. Cells overexpressing GILZ grew faster than CTRL cells. There was no dif ference in spontaneous apoptosis between pGILZ and CTRL clones. We next investigated whether over expression of GILZ affected AKT activation. p AKT, currently the active form of AKT, was more abundant in pGILZ clones than in CTRL clones, whereas the status of phospho ERK 1/2 remained unchanged.