Expression of Epidermal Growth Factor-like Domain 7 is Increased by Transcatheter Arterial Embolization of Liver Tumors

Background: Epidermal growth factor-like domain multiple 7 (EGFL7), recently identified as a secretedprotein regulated by oxygen exposure, plays a critical role in promoting metastasis of hepatocellular carcinoma(HCC). Transcatheter arterial embolization (TAE) is widely used for treatment of HCC, resulting in hypoxia intumors and surrounding liver tissues. Accordingly, we proposed the hypothesis that there could be a relationshipbetween expression of EGFL7 and response to TAE. Materials and
Methods: We established a rabbit VX2liver tumor model using percutaneous puncture technique guided by computed tomography. TAE and shamembolization were performed and the results were confirmed by MRI 3 weeks after inoculation. We investigatedthe EGFL7 expression of the two groups at 6h and 3 days after intervention by means of immunohistochemistryand Western blotting.
Results: Immunohistochemical staining demonstrated that the levels of EGFL7 proteinsignificantly increased in the TAE-treated tumors compared with the control group at 6 hours (P=0.031) and 3days (P=0.020) after intervention. Meanwhile, the relative EGFL7 protein detected in TAE group also up-regulatedcompared with the control group at 6 hours (P=0.020) and 3 days (P=0.024) after intervention.
Conclusions:This study reveals an increase of EGFL7 expression in rabbit VX2 liver tumors after TAE. The role of EGFL7in HCC, especially its biological behavior after TAE, needs further investigation.