Loss of expression and mechanism of early growth response gene-3 in human oral squamous carcinoma

Abstract

To evaluate the expression of early growth response gene-3 (EGR3) in human oral squamous carcinoma tissue, non-adjacent tissue and oral carcinoma cell lines and detect the effects of EGR3 expression on the biological behaviors of oral squamous carcinoma cell lines. From October 2008 to December 2009, the expression of EGR3 was detected in 20 human oral squamous carcinoma tissue, non-tumor adjacent tissue and 2 oral carcinoma cell lines. The total-length plasmid of EGR3 was constructed and transfected into oral squamous carcinoma line Tca-8113 to observe the proliferation and apoptosis. There was a high-level expression of EGR3 mRNA in normal oral squamous epithelial and non-tumor adjacent tissues (2.108 ± 0.996 and 1.721 ± 1.196). And a low-level expression or a loss of EGR3 mRNA in human oral squamous carcinoma tissue and oral carcinoma cell lines (0.007 ± 0.005 and 0.007 ± 0.001) (both P < 0.05). Tca-8113 transfected by EGR3 plasmid had a high-level expression of EGR3 mRNA capable of inhibiting the proliferation of Tca-8113 and promoting its apoptosis dramatically. The stimulating index in overexpression of EGR3 was lower than control group (0.35 ± 0.11 vs 0.82 ± 0.21, P < 0.05). After overexpression of EGR3 in Tca-8113, the frequency of middle-Late stage of apoptosis (Annexin-V/PI double positive) was higher than the frequency of vector group (23.12% ± 6.65% vs 5.96% ± 0.98%, P < 0.05). A low-level expression or a loss of EGR3 in human oral squamous carcinoma and an over-expression of EGR3 in human oral squamous carcinoma may inhibit the proliferation and promote apoptosis of oral squamous carcinoma.