ECRG4 inhibits growth and invasiveness of squamous cell carcinoma of the head and neck in vitro and in vivo

ECRG4 has been shown to be a candidate tumor suppressor in several tumors, but its role in head and neck cancer remains poorly understood. In the present study, the effect of ECRG4 on head and neck cancer was investigated in vitro and in vivo. pFLAG-CMV-2-ECRG4 was stably transfected into squamous cell carcinoma of the head and neck (SCCHN) M2 cell lines to overexpress the ECRG4 gene. Real-time PCR and western blot analysis were performed to detect gene and protein expression, respectively. An MTT assay and flow cytometric analysis were used to detect the growth of M2 cells. Matrigel™ invasion and scratch assays were applied to observe the invasion and migration of the cells. A tumorigenicity assay was applied to test the tumor growth and cervical lymph node metastasis in vivo. Based on the data, pFLAG-CMV-2-ECRG4 significantly increased the expression of ECRG4 in the M2 cells. The constructed plasmid inhibited cell proliferation and promoted cell cycle arrest and apoptosis in the M2 cells. The growth rate and metastasis of the tumor cells in xenografts were suppressed following the overexpression of ECRG4 in nude mice. These data suggest that ECRG4 plays a significant role in the regulation of growth and metastasis in SCCHN, providing new clues for the diagnosis and therapy of SCCHN.