Objective To construct small interfering RNA（siRNA） eukaryotic expression vector specific for human hnRNP K gene，and to observe its silencing effects on hnRNP K gene in A549 cells.Methods The expression vectors of pSUPER/hnRNP K siRNAa，pSUPER/hnRNP K siRNAc and pSUPER/siRNAn were constructed by gene recombination and then transfected into the A549 lung carcinoma cell line by using Lipofectamine2000（a and c respectively represented A and C fragments in hnRNP K coding sequence contained 19 nts，n represented nonsense fragment as control）.The mRNA and protein were harvested after 24 h and analyzed for the expression of hnRNP K by RT-PCR and Western blotting respectively.Results The siRNA vector targeted to hnRNP K successfully decreased hnRNP K mRNA and protein levels 24 h after transfection in A549 cells.Relative expressed doses of hnRNP K mRNA in lung cancer cells transfected by hnRNP K siRNAa and hnRNP K siRNAc respectively were 0.24±0.53 and 0.28±0.57 after 24 h，which were significantly lower than that in the control group（both Plt;0.01）.The gray scale values of hnRNP K protein were 0.23±0.11 and 0.28±0.09 respectively，which were also significantly lower than those in the control group（both Plt;0.05）.And pSUPER/hnRNP K siRNAa was the most effective one.Conclusion Eukaryotic expression vector of siRNA specific for hnRNP K is successfully constructed，which lays the basis for the function study of hnRNP K gene and its application in the treatment of lung carcinoma.
Objective To explore the effect of toremifene on estrogen receptor （ER） expression and tumor micro-angiogenesis in rat Lewis lung carcinoma. Methods Cell suspension of rat Lewis lung carcinoma was implanted into 40 female Wistar rats subcutaneously. The rats were randomly divided into a control group，a estradiol group （0.006 mg/mL），a low dose toremifene group （0.25 mg/mL） and a high dose toremifene group （5 mg/mL）. Tumor size was measured every 3 days and the tumor growth curve was charted. On 15th day，the tumor weight and the growth inhibition rate were measured. Immunohistochemical method was used to detect the expressions of estrogen receptor α （ERα），estrogen receptor β （ERβ），vascular endothelial growth factor （VEGF），and platelet endothelial cell adhesion molecule-1 （PECAM-1）. Integral optical density （IOD） of ERα，ERβ and VEGF was calculated by image analysis software. Quantitative method of Weidner with PECAM-1 was employed for microvessel density （MVD） count. Results Tumor size of the four groups all presented a quadratic function growth trend with time （Plt;0.05）. Tumor growth speed was slower in toremifene groups of low and high doses than that in the control group and the estradiol group. The growth inhibition rate of the estradiol group，the low dose toremifene group and the high dose toremifene group was －15.1%，22.6%，and 45.1%，respectively. The expressions of ERα，VEGF，and MVD in the estradiol group were significantly higher than those in the control group，the low dose toremifene group and the high dose toremifene group （all Plt;0.05）. The expressions of ERα，VEGF，and MVD in the low dose toremifene group were significantly lower than those in control group，but higher than those in high dose toremifene group （all Plt;0.05）.The expression of ERα was positively related to VEGF （r=0.664，Plt;0.05） and MVD（r=0.593，Plt;0.05）. Conclusion Toremifene can inhibit tumor growth，which maybe involved in inhibiting ERα mediated VEGF expression.