Study On The Gene Expression Of Vascular Endothelial Growth Factor (VEGF) & Its Receptors In Human Hepatocellular Carcinoma And The Inhibitory Effect Of Antisense VEGF RNA On The Growth Of Liver Cancer Cell In Vivo & In Vitro

Liver cancer is one of the common types of gastrointestinal tumors with poor prognosis % metastasis and high mortality , in which hepatocellular carcinoma (HCC) accounts for about 95% . Although the different available multi-modalities of therapies , including radical surgical operation % intervention therapy > laser therapy et al, have currently been used in the treatment for liver cancer , the prognosis of liver cancer has not been markedly improved. Therefore, it has an important clinic significance to study on the mechanism of the development and progression of liver cancer and the new strategies for the treatment of liver cancer with the molecular biology. With the development of the basic research on oncological fields, it was found that many tumors have the overexpression in growth factors & their receptors, and progression of tumors depends on angiogenesis. The vascular endothelial growth factor ( VEGF) is an important factor which elicits the angiogensis in tumors. It takes an important role in the growth, differentiation , metastasis, proliferation of tumors. The HCC is well known to be vascular rich tumors and its growth is highly depended on angiogenesis, so VEGF is considered to have key roles in the development of HCC. By now , the systemic researches on therelationship between the expression of VEGF and histopathologic type, metastasis activity > angiogenesis of HCC have not been reported. And there are also no reports on gene therapy against angiogeneis of liver cancer. This study contains three parts of work: The first, the relationships between the expression of VEGF gene & its receptors ( flk-1 , flt-1 ) in HCC and the tumor grade , tumor metastasis , angiogenesis of liver cancer. The secondi the inhibitory effect of VEGF antisense RNA on the growth of 7721 hepatocellular cell line (7721 cancer hepatocytes)in vivo. The third, the inhibitory effect of VEGF antisense RNA on 7721 cell in nude mouse.Part I : Study on the expression of VEGF and its receptors and its relationship to metastasis activity and angiogenesis of human HCC1. Expression of VEGF gene in human HCC and normal liver tissue The gene expression of VEGF in 60 human HCCs and 10 normalliver were studied by RT-PCR method. The expressive rates of HCCs and normal tissue were 78.3% and 30% respectively. The levels of VEGFmRNA (VEGFmRNA/P -actin mRNA) were 0.79 + 0.26 in grade IK 1.12 + 0.25 in grade IIK 1.36?.19 in grade IV, respectively . The expression levels of VEGFmRNA were positively correlated to pathologic grades^ embolus and envelops of tumors.2. The protein expression of VEGF and its specific receptor in human HCC and normal liver tissueThe protein expression of VEGF in 60 human HCCs and 10 normal liver were studied by immunohistochemistry .The expression rates of HCCs and normal tissue were 81.3% and 40% respectively. The level of VEGF protein was also significantly correlated to pathologic grades>embolus and capsules of the tumors.The protein expression of flk-l/flt-1 in 60 human HCCs and 10 normal liver were studied by immunohistochemical method. The expression rates of flk-1 in HCCs and normal tissue were 88.3% and 50% respectively. The expression rates of flt-1 in HCCs and normal tissue were 80% and 40% respectively. The levels of fik-l/fit-1 were correlated to pathologic grades^ embolus and capsules of the tumors.The overexpressions of VEGFmRNA -. VEGF protein and its fll-l/flk-1 were found in HCC. It suggested that the VEGF gene play an important role in the malignant progression of cancers. The overexpression of VEGF and the correlation between VEGF expression and tumor grade provided a useful parameter for evaluating the degree of malignancy at molecular level and for selecting the target gene in gene therapy.Part II The inhibitory effect of VEGF antisense RNA on the growth of HCC cells in vitroBecause there was no effective treatments on liver cancers, it is very urgent and important to find out new methods to solve this problem. According to the results in part I , w...