| Objective:Hypoxia is a common characteristic of locally advanced solid tumors that has been associated with diminished therapeutic response, and more recently, with malignant progression, that is, an increasing probability of recurrence, loco regional spread, and distant metastasis. The hypoxia inducible factor 1(HIF-1) is a heterodimer transcription factor that is an important regulator of the growing tumor's response to hypoxia in mammal or human body. It consists of HIF-1αand HIF-1βsubunits, HIF-1 activity in tumors depends on the availability of the HIF-1αsubunit. As nuclear transcription factor, HIF-1 are important in mammal of regulating the growing development, physiology and pathology. The study indicated: HIF-1α, which has high expression in hepatocellular carcinoma and in other malignant tumors, is associated with the tumor aggressiveness, migration and mortality. VEGF, as a target gene of HIF-1α, stimulating angiogenesis, promoting the aggressiveness and migration in hepatocellular carcinoma, is regulated by HIF-1α. The activity of HIF-1 may be the key to cure the malignant tumors. At the present time, there was little deeply study about relation of HIF-1αand VEGF in clinical research. In this research, we explored whether VEGF can be up-regulated by HIF-1αin hepatocellular carcinoma. The cell lines of SMMC-7721 and BEL-7402 were treated with YC-1 [3-(5'- hydroxymethyl-2'-furyl)-1-benzylindazole] and ASODN of HIF-1αrespectively. By detecting the expression of HIF-1α,VEGFmRNA and protein in SMMC- 7721 cell and BEL-7402 cell culturing in normal and treated conditions by RT-PCR and Western blot, we investigate the relation of HIF-1αand VEGF, and the potential of HIF-1αas a valid therapeutic target.Methods: SMMC-7721 cells and BEL-7402 cells were divided as control group and experiment group. The control group were cultured with normal condition, the experiment group were treated by YC-1 or ASODN of HIF-1αrespectively with various concentration. All of the cells were collected on time (after cultured 24 hours). The expression of HIF-1α,VEGF mRNA levels was evaluated by RT-PCR. The HIF-1α,VEGF protein levels in cytoplasm was evaluated by western blot. The OD value of electrophoresis strip of DNA product or that of HIF-1α,VEGF protein was analyzed by gel scanner. Beta-actin was used as an internal standard. The relative expression level of HIF-1α,VEGF was represented with the ratio between produces of HIF-1α,VEGF and that of beta-actin. Data were analyzed with ANOVA and T test using SPSS13.0 statistical software. A level of P<0.05 was considered statistically significant.Results: 1 In SMMC-7721 cells and BEL-7402 cells, the expression of HIF-1αand VEGF mRNA in experiment group were obviously down-regulated compared with control group, the differences of the expression of HIF-1αand VEGF mRNA were statistically significant (P<0.05).2 In SMMC-7721 cells and BEL-7402 cells, the expression of HIF-1αand VEGF protein in experiment group were obviously down-regulated compared with control group, the differences of the expression of HIF-1αand VEGF protein were statistically significant (P<0.05).3 In SMMC-7721 cells and BEL-7402 cells, following the increasing of the concentration of YC-1 or ASODN of HIF-1α, the expression of HIF-1αmRNA were decreased gradually, and the differences of the expression of HIF-1αmRNA were statistically significant within the experiment group(P<0.05). The expression of HIF-1αmRNA showed a dose-dependent in cells cultured with YC-1 or ASODN of HIF-1α. The expression of VEGF mRNA (including VEGF121 and VEGF165) were decreased gradually in experiment group, the differences of the expression of VEGF mRNA were statistically significant (P<0.05). VEGF165 mRNA has high expression compared with VEGF121 mRNA.4 In experiment group of SMMC-7721 cells and BEL-7402 cells, following the increasing of the concentration of YC-1 or ASODN of HIF-1α, the expression of HIF-1αprotein showed decrease, it was statistically significant (P<0.05), and it showed a dose-dependent in cells cultured with YC-1 or ASODN of HIF-1α. The expression of VEGF protein were obviously down-regulated in cells cultured with YC-1 or ASODN of HIF-1α, it was statistically significant, too (P<0.05).Conclutions: 1 The high expression of HIF-1αand VEGF in SMMC-7721 cells and BEL-7402 cells indicated that HIF-1αand VEGF were associated with the occurrence and development of HCC.2 YC-1 inhibits the expression of HIF-1αat gene level and protein level. The expression of VEGF was down-regulated at gene level and protein level. ASODN of HIF-1αcould inhibited the expression of HIF-1αand VEGF at gene level and protein level, too. The result indicated that HIF-1αcan promote the expression of VEGF at gene level and protein level, in other word, that the expression of HIF-1αcan up-regulated the expression of VEGF in hepatocellular carcinoma.3 Following the increasing of the concentration of YC-1 or ASODN of HIF-1αin experiment group in SMMC-7721 cells and BEL-7402 cells, the expression of HIF-1αand VEGF were decreased gradually. The result indicated that it has high potential to treatment tumor of HIF-1αas a valid therapeutic target.
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