Abstract: Objective To explore the relationship between expression of inhibitor of growth family member 4（ING4） protein and microvessel density in hydatidiform mole(HM) and the clinical significance. 
Methods Immunohistochemistry(PV method) was performed to detect the expression of the ING4 protein and microvessel density in HM tissue and the tissues of chorionic villi of normal early pregnancy. They were divided into hydatidiform mole group(n=30) and chorionic villi of normal early pregnancy group(n=20). 
Results The expression of ING4 protein was lower in HM group than in chorionic villi of normal early pregnancy group, and significantly lower in complete hydatidiform mole(CHM) group and partial hydatidiform mole(PHM) group than in chorionic villi of normal early pregnancy group(P＜0.05). There was no significant difference in ING4 protein expression between CHM group and PHM group(P＞0.05). The expression of ING4 protein in the groups with and without high-risk factors was lower than that in the chorionic villi of normal early pregnancy group(P＜0.05). There was no significant difference in ING4 protein expression between the groups without high-risk factors and those with high-risk factors(P＞0.05). The results of univariate analysis showed that the expression of ING4 protein in HM tissue was not related to clinical high-risk factors(P＞0.05). The MVD value of the chorionic villi of normal early pregnancy group was higher than that of the HM group, and lower in the PHM group and the CHM group than in chorionic villi of normal early pregnancy group, and the value in the PHM group was higher than that of the CHM group(P＜0.05). The MVD values of the groups with or without high-risk factors were lower than those in chorionic villi of normal early pregnancy group, and the value in the group with high-risk factors was higher than that of the group without high-risk factors(P＜0.05). The results of univariate analysis showed that the MVD value in HM tissue was not associated with clinical high-risk factors(P＞0.05). The expression of ING4 protein in HM tissue was not correlated with MVD(r=0.137, P=0.470). 
Conclusion The ectopic and downregulated expression of ING4 protein promotes the occurrence of HM. ING4 protein expression is not associated with clinical risk factors. The absence of blood vessels in HM tissue is involved in the development of HM, and is not related to clinical high-risk factors. ING4 protein expression in HM tissue has no significant correlation with MVD.

Key words: ING4 protein, microvessel density, hydatidiform mole