Objective To explore the influence on the expressions of vascular endothelial growth factor (VEGF) gene and matrix metalloproteinase-2 (MMP-2) gene in hepatocellular carcinoma of SMMC-7721 cells with RNA interference (RNAi) silencing the expression of hypoxia inducible factor-1α (HIF-1α) gene. Methods Firstly, constructed short hairpin RNA (shRNA) targeting for HIF-1α gene, and then transfected it to SMMC-7721 cells after combining with plasmid. The SMMC-7721 cells were divided into three groups, silencing group, negative control group, and blank control group, which were transfected with HIF-1α-shRNA-pGenesil-1 recombinant vector, shRNA-HK-pGenesil-1 recombinant vector, and pGenesil-1 vector respectively. Transfection cells were screened by the concentration of 500 μg/mL G418, and then positive and negative cell clones with transfection recombination carrier were obtained. Detected the expressions of HIF-1α mRNA, VEGF mRNA, and MMP-2 mRNA in the 3 groups with real time PCR (RT-PCR) technology, under the condition of hypoxic training 6 h, 12 h, and 24 h, as well as conventional oxygen training. Results There was no expression of HIF-1α mRNA at conventional oxygen condition in the 3 groups, and there was no significant difference in expressions of VEGF mRNA and MMP-2 mRNA among the 3 groups (P>0.05) at the condition of conventional oxygen training. The expressions of HIF-1α mRNA, VEGF mRNA, and MMP-2 mRNA in the silencing group, compared with the the negative control group and the blank control group, were obviously decreased (P<0.05) under the condition of hypoxic training (6, 12, and 24 h), while there was no significant difference between the negative control group and the blank control group at each time point (P>0.05), but the expressions of HIF-1α mRNA, VEGF mRNA, and MMP-2 mRNA in the 3 groups under every condition of hypoxic training were all higher than those of conventional oxygen condition (P<0.05). Under the condition of hypoxic training, the expressions of HIF-1α mRNA, VEGF mRNA, and MMP-2 mRNA in the 3 groups decreased over time, and there was significant difference between any 2 time points in each group (P<0.05). Conclusion RNAi technique can effectively silence the expression of HIF-1α mRNA of SMMC-7721 cells, and then silence the expressions of VEGF and MMP-2 mRNA, to inhibit the invasion and metastasis of hepatocellular carcinoma.
ObjectiveTo investigate the correlations among the cadual homeobox gene 2 (CDX2), hypoxia inducible factor-1α (HIF-1α) protein expressions, and tumor budding in the colorectal cancer (CRC). MethodsIn this study, 63 CRC specimens surgically removed in the First Affiliated Hospital of Xi’an Jiaotong University from January 2012 to September 2015 were collected. The CDX2 and HIF-1α protein expressions were detected by immunohistochemical staining streptavidin-biotin peroxidase two-step method. The staining and the grade of tumor budding were observed under an optical microscope, and the correlation was analyzed using Spearman test. ResultsThe positive expressions of CDX2 and HIF-1α proteins in the CRC tissues were 35 (55.6%) and 47 (74.6%) cases, respectively, which was a negative correlation in the CRC (rs=–0.302, P=0.017). The positive expressions of CDX2 and HIF-1α proteins in the tumor budding of colorectal cancer were 21 (51.2%) and 26 (63.4%) cases, respectively, which was also a negative correlation in the tumor budding of CRC (rs=–0.336, P=0.031), but there was no statistic correlation between the grade of tumor budding and CDX2 or HIF-1α positive protein expression in the CRC (rs=0.113, P=0.370; rs=–0.026, P=0.838). ConclusionsThe positive expression between CDX2 and HIF-1α has a negative correlation in the same CRC specimen and which has a negative correlation in tumor budding. There is no statistic correlation between grade of tumor budding and CDX2 or HIF-1α protein expression in the CRC. Hypoxia environment may be involved in the downregulation of CDX2 level during the malignant progression of CRC.