The overexpression of epithelial cell adhesion molecule (EpCAM) in glioma.

Epithelial cell adhesion molecule (EpCAM) is overexpressed in various neoplasms as a tumor-associated antigen and absent in natural brain. However, little is known about EpCAM's expression in gliomas. To investigate the expression of EpCAM in gliomas and understand the correlation of EpCAM expression with malignancy, proliferation, angiogenesis, and prognosis, we studied the expression of EpCAM in 98 glioma samples by immunohistochemistry and by western blotting (N = 12). Correlative analysis of EpCAM overexpression with microvessel density (MVD), Ki-67 expression, age, and gender were made. Survival data was analyzed with Kaplan-Meier method and Cox Proportional Hazard Model. Immunohistochemistry results showed EpCAM was widely expressed in glioma (90.8 %). The overexpression rate of WHO grade IV gliomas was significantly higher EpCAM overexpression correlated significantly with Ki-67 expression and MVD. Western blot analysis also revealed a stepwise increase in EpCAM expression from WHO II to IV glioma. The overall survival of WHO III and IV glioma patients with EpCAM overexpression was obviously lower than that without EpCAM overexpression. EpCAM overexpression was an independent prognostic factor for overall survival in glioma patients. This study firstly shows that EpCAM overexpression correlates significantly with malignancy (WHO grades), proliferation (Ki67), angiogenesis (MVD), and prognosis in gliomas. EpCAM may participate in tumorgenesis of gliomas.

Overexpression of EpCAM and Trop2 in pituitary adenomas.

We sought to investigate the expression of EpCAM and Trop2 in Pituitary adenomas (PAs) and study the correlation of protein expression with invasiveness, proliferation, clinical functioning, recurrence/progression, and some other factors. We investigated the expression of EpCAM and Trop2 in 74 samples of PAs by immunohistochemistry and made correlative analysis of protein overexpression with clinicopathological parameters. Follow-up data was analyzed for recurrence/progression with Kaplan-Meier method and Multivariate Cox regression analysis. Immunohistochemistry results showed that overexpression rates of EpCAM and Trop2 were 51/74 (68.9%) and 43/74 (58.1%), respectively. For both EpCAM and Trop2, PAs with invasiveness showed a higher overexpression rate than PAs without invasiveness (PEpCAM = 0.001; PTrop2 = 0.006). Nonfunctional Pituitary adenomas (NFPAs) demonstrated a higher EpCAM overexpression than functional Pituitary adenomas (FPAs) (P = 0.026). Both EpCAM and Trop2 overexpression correlated significantly with expression of proliferation factor Ki-67 (PEpCAM = 0.011; PTrop2 = 0.000), but not with gender and age. Follow-up analysis revealed that Trop2 overexpression was a significantly predictive factor for recurrence/progression by means of Kaplan-Meier method d (P = 0.028) and Multivariate Cox regression analysis (P = 0.025). This study reveals that both EpCAM and Trop2 overexpression in PAs correlate significantly with invasiveness and proliferation. EpCAM presents a potential target for differential diagnosis and immunotherapy for NFPAs. Follow-up analysis shows that Trop2 is a predictive factor for recurrence/progression for PAs.

Expression of hepatocyte growth factor and its receptor c-Met in human pituitary adenomas.

Hepatocyte growth factor (HGF) and its receptor c-Met have been known as key determinants of growth and angiogenesis in some brain tumors like gliomas, meningiomas, and schwannomas. But little is known about their expression in pituitary adenomas. In this study, the expression of HGF and c-Met in pituitary adenomas of different histology types was investigated by immunohistochemistry, and correlative analysis of their expression with microvessel density (MVD), Ki-67 expression, and other clinicopathologic factors was made. The results showed that the expression of HGF and c-Met exists in 98% (64 of 65) and 92% (60 of 65) pituitary adenomas, respectively, and co-expression of them existed in 91% (59 of 65) adenomas. HGF had significant correlation with MVD (Spearman's correlation coefficient, r = .31, P = .01) and Ki-67 (r = .32, P = .01). c-Met had significant correlation with MVD (r = .30, P = .02) and Ki-67 (r = .38, P = .00). HGF and c-Met expression had no significant correlation with age or extrasellar extension. There were no significant differences in HGF and c-Met expression between pituitary adenomas of different histology types. The results indicate that HGF and c-Met are widely expressed in pituitary adenomas, and their expression correlates with MVD and Ki-67 expression.