OBJECTIVETo investigate the expression of LRG-1 in clinical specimens and Tca8113 cell line of tongue carcinoma and analyze the relationship between LRG-1 expression and the clinicopathological parameters.

METHODSLRG-1 expression was detected in 40 tongue squamous cell carcinoma (TSCC) tissues and paired normal adjacent tissues, 20 atypical hyperplasia tissues of the tongue, and 20 tissues of tongue cancer in situ using immunohistochemical method. The expression of LRG-1 in Tca8113 cell line was detected using flow cytometry. The expression of LRG-1 was also detected in human TSCC tissues and Tca8113 cells with Western blotting. The effect of LRG-1 on the proliferation of HUVECs was determined using MTT assay, and its effect on angiogenesis was evaluated with Matrigel tube formation assays.

RESULTSHuman TSCC tissues had a significantly higher rate of positive expression for LRG-1 (85%, 34/40) than the adjacent tissues (10%, 4/40), invasive tongue cancer (30%, 6/20), and tongue cancer in situ (50%, 10/20) (P<0.05). LRG-1 expression was correlated with the degree of tumor differentiation, clinical stage and lymph node metastasis of the tumor (P<0.05) but not with the patients' age or gender. In the in vitro experiment, LRG-1 promoted HUVEC proliferation and angiogenesis.

CONCLUSIONAbnormal LRG-1 expression is present in the human TSCC tissue and Tca8113 cells. LRG-1 can promote HUVEC proliferation and angiogenesis in vitro, suggesting its possible role in promoting tumor angiogenesis.