CD73 promotes proliferation and migration of human cervical cancer cells independent of its enzyme activity.

BACKGROUND: CD73 has both enzymatic and non-enzymatic functions in cells. As a nucleotidase, CD73 plays its enzymatic function by catalyzing the hydrolysis of AMP into adenosine and phosphate. In addition to this, accumulating data have shown that CD73 is a key regulatory molecule involved in cancer growth and metastasis, but this non-enzymatic function of CD73 in cervical cancer cells has not been well studied.

METHODS: CD73 was overexpressed by pcDNA-NT5E expression vector transfection in Hela and SiHa cells. Cell's proliferation and migration were evaluated by MTT and scratch healing assay. The CD73 specific antagonist -APCP was used to inhibit CD73 enzymatic activity. And the effect of APCP on CD73 activity was determined by high performance liquid chromatography (HPLC). Expression level was assessed by qRT-PCR and western blotting.

RESULTS: In the present study, we used Hela and SiHa cell lines to evaluate the effects of CD73 on cervical cancer cells proliferation and migration, and further explore the potential regulating mechanisms. Our data showed that CD73 overexpression significantly promoted cervical cancer cells proliferation and migration, and this promotive effect was not reverted by blocking CD73 enzymatic activity, both in Hela and SiHa cells. On the other hand, our data also showed that high concentration of adenosine inhibited Hela and SiHa cells proliferation and migration. These results demonstrated that the promotive effect of CD73 on cervical cancer cells proliferation and migration in vitro was independent from its enzymatic activity (i.e. production of adenosine). Furthermore, the expressions of EGFR, VEGF and Akt were significantly increased in CD73 overexpression Hela and SiHa cells.

CONCLUSIONS: Our data suggested that CD73 might promote proliferation and migration via potentiating EGFR/Akt and VEGF/Akt pathway, which was independent of CD73 enzyme activity. These data provide a novel insight into the regulating function of CD73 in cancer cells and suggest that CD73 may be promising therapeutic target in cervical cancer.