Impact Of Rapamycin Combined Cisplatin On The Tumor Growth Of Human Cervical Carcinoma Subcutaneous Xenograft In Nude Mice

Background:Recently, mammalian target of rapamycin (mTOR) signaling pathway for the central link in a growth regulator which is widely applied to the research of cancer therapy, its specific inhibitor rapamycin is a hot research. Some scholars have found that hypoxia inducible factor-1 a (HIF-la) may be the key transcription factors to adapt to the hypoxia condition for most cells.HIF-1αwas overexpression in multiple malignant neoplasm. HIF-1αcan activate expression of a variety of hypoxia adaptive genes such as vascular endothelial growth factor (VEGF), erythropoietin (EPO) and maintain the energy metabolism of tumor cells, stimulate angiogenesis, promote proliferation and metastasis of neoplasm. VEGF is the most critical angiogenesis-promoting factor. It was Well-known that It was correlation between angiogenesis and growth and metastasis of tumour. Therefore, the antagonistic activity of HIF-1αmay be potential target For tumour therapy.Recent studies show that rapamycin can block the HIF-la expression in transcription and translation levels, and play a role in Anti-tumor, thus it provides a new idea for rapamycin combined with other classical drugs used in cancer therapy.Objective:To study the inhibitive effect of rapamycin combined cisplatin on the tumor growth of human cervical carcinoma subcutaneous xenograft in nude mice and impact on the expression of HIF-1αand VEGF, This study will help to search for more effective drugs of tumor therapy.Methods:1. Establish nude mice xenograft model.There were four groups in this experiment which was control group, RPM group, DDP group and combin- ation group. Nude mice were sacrificed after 2 weeks of drug intervention. Observe tumor weight and volume and calculate inhibition rate. Save tumor tissue for subsequent experiments.2.The expression of HIF-laand VEGF was detected by immuno-fluorescence,RT-PCR and western blot.HIF-1αgene silencing was investig-ated.3.Using SPSS 16.0 software to assay the data.Results:1 Tumor volume of control group,PRM group,DDP group andcombination group were 1227.46±56.654 mm3,797.81±111.98 mm3, 3766.155±132.274 mm3,,568.701±36.115 mm3, and compared with control group, Tumor inhibition rates were respectively 35.0%,37.6%,53.7%, the difference was statistically significant (P<0.05) and also obvious in between the PRM and combination group,DDP and combination group (P<0.05), while not (P= 0.688) in between the PRM and DDP group.2 Immunohistochemical analysis of the expression of HIF-1αand VEGF. HIF-la was staining in the nuclear and cytoplasm and VEGF was staining only in the cytoplasm, HIF-1αand VEGF positive cells of the experimental group were significantly weaker than the control group especially combin-ation group.3 RT-PCR and Western blot display that compared with control group, HIF-la and VEGF expressions of RPM group,DDP group and combination group were obviously downregulated, the difference was statistically significant (P<0.05).and also obvious in between the PRM and combination group,DDP and combination group (P<0.05), while not (P= 0.068) in between the PRM and DDP group.This study reveals that HIF-la and VEGF expressions of experimental group were inhibited in the levels of trans-cription and translation.Conclusion:1. Rapamycin inhibited the proliferation of cervical cancer hela cells and reduced HIF-la, VEGF expressions.2. Not only could rapamycin combinated cisplatin inhibit the prolifer-ation activity of cervical cancer Hela cells and let down HIF-la, VEGF expressions, but reduce the side effects of traditional chemotherapy, its efficacy was significantly better than single drug. So the combined action are expected to become a new method of cervical cancer treatment.