Phospholipase C-γ1 is required for the epidermal growth factor receptor-induced squamous cell carcinoma cell mitogenesis

• Published in: Biochemical and biophysical research communications Vol. 397; no. 2; pp. 296 - 300
• Main Authors: Xie, Zhongjian, Chen, Ying, Liao, Er-Yuan, Jiang, Yi, Liu, Fu-You, Pennypacker, Sally D.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 25.06.2010
• Subjects: Epidermal growth factor receptor; Mitogenesis; Phospholipase C-γ1; Squamous cell carcinoma; Squamous cell carcinoma; EGF; PLC; siRNA; DAG; IP3; EGFR; Epidermal growth factor receptor; PLC-δ1; SCC; Phospholipase C-γ1; PLC-γ1; PLC-β1; Mitogenesis
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2010.05.103

The epidermal growth factor receptor (EGFR) is a key driver in the process of squamous cell carcinoma (SCC) cell mitogenesis. Phospholipase C-γ1 (PLC-γ1) is a downstream target of EGFR signaling, but the role and necessity of PLC-γ1 in EGFR-induced cell mitogenesis remain unclear. In the present study, we report an elevated expression of PLC-γ1 in human SCC biopsies relative to adjacent normal epidermis, and in human SCC cell lines compared to normal human keratinocytes. EGFR-induced SCC cell mitogenesis was blocked by small interfering RNA knockdown of PLC-γ1. However, inhibition of the catalytic activity of phospholipase C had no effect on EGFR-induced SCC cell mitogenesis. In response to the EGFR ligand epidermal growth factor (EGF), PLC-γ1 was translocated not only to the plasma membrane but also to the nucleus. These data suggest that PLC-γ1 is required for EGFR-induced SCC cell mitogenesis and the mitogenic function of PLC-γ1 is independent of its lipase activity.