The Study On The Function Of DLL4 In The Proliferation Of Endothelial Cells

BACKGROUND AND OBJECTIVES: There is an intimate relationship between the angiogenesis of tumors and the growth of tumors. In the research field of the angiogenesis, much attention is paid to DLL4. Studies have shown that vascular endothelia cells of tumor express DLL4. DLL4 may control the angiogenesis by regulating the differentiation and proliferation of vascular endothelia cells.In this study, we have investigated whether the vascular endothelia cells express DLL4 and the downstream genes HEY1 and HEY2 of DLL4, and DLL4 functions on the proliferation of vascular endothelia cells.MATERIALS AND METHODS: Human microvascular endothelia cells(HMECs) were cultured. The proliferation of HMECs was analysed by MTT. The expression of DLL4 mRNA, HEY1 mRNA and HEY2 mRNA were detected by RT—PCR in HMECs. RNA interference of DLL4 was used to study the effect of DLL4 in the proliferation of HMECs.RESULTS: The results of RT-PCR indicated that HMECs expressed DLL4 mRNA, HEY1 mRNA and HEY2 mRNA. The results of RNA interference showed the expression of DLL4 mRNA of 100nmol/L siRNA DLL4-duplex group and 200nmol/L siRNA DLL4-duplex group were down-regulated. The MTT results showed the absorption of 100nmol/L siRNA DLL4-duplex group and 200nmol/L siRNA DLL4-duplex group increased. The results illustrate the inhibition of DLL4 by siRNA promotes the proliferation of HMECs. It means DLL4 inhibits the proliferation of HMECs.CONCLUSION: HMECs express DLL4 mRNA, HEY1 mRNA and HEY2 mRNA. DLL4 inhibits the proliferation of HMECs.