Résumé
Background and purpose:As a member of the catenin family, Delta-catenin protein could promote proliferation and invasion of tumor cells, but the accurate mechanism of Delta-catenin promoting cell proliferation is not clear. In the present study, we illustrated that Delta-catenin’s effect on cell apoptosis and their relationship with mitogen-activated protein kinase (MAPK) signaling pathway, and the possible mechanism was also explored for Delta-catenin promoting invasion and proliferation of tumor cells. Methods:The alterations of p38 and c-jun N-terminal rinasel JNK protein activity were detected in SPC and SK lung cancer cell lines with Delta-catenin overexpression or not, by Western blot method. At the same time, the apoptotic number of tumor cells was also examined by FCM method. Furthermore, the number of invasive tumor cells was examined by Matrigel invasive experiment. Results:Compared with untreated group and empty vector group, the activity of p38 protein was unchanged in lung cancer cell lines with Delta-catenin overexpressed (P>0.05), but the activity of JNK protein was decreased signiifcantly (P<0.05),meanwhile, apoptotic proportion of tumor cells were also reduced (P<0.05), and invasive ability of tumor cells was enhanced signiifcantly (P<0.05). Conclusion:Delta-catenin probably decreases apoptosis number of lung cancer cells via inhibiting the activity of JNK pathway, and then promotes invasive ability of tumor cells.
Résumé
Background and purpose: As a member of Catenin family, little is known about expressive signiifcance and mechanism of Delta-catenin in numerous tumors. In present study, we investigated the expression of Delta-catenin in breast cancer tissues and its correlation with the prognosis of patients. Methods:We examined the expression of Delta-catenin and its correlation with clinicopathological factors of patients by immunohistochemistry in 92 cases of breast cancer tissues with tissue micro-array. The mRNA and protein expression of Delta-catenin were also detected in another 32 cases of frozen paired breast cancer tissues and normal breast tissues. Results:Compared with normal breast tissues, the mRNA and protein expression of Delta-catenin were increased in breast cancer tissues, and expression of Delta-catenin was closely associated with histological grade and lymph node metastasis (P=0.016 and 0.022, respectively). Moreover, Kaplan-Meier survival analysis revealed that patients with high Delta-catenin expression had shorter survival than patients with low expression (P=0.015), and multivariate Cox analysis revealed that high Delta-catenin expression was also an independent prognostic factor (P=0.017). Conclusion:Our results suggest that Delta-catenin acts as an oncoprotein when overexpressed in breast cancer, and its expression is associated with poor prognosis of patients.