Objective To analyze the effect of siRNA targeting MIF( MIFsiRNA) on the growth of colorectal cancer xenografts and the life quality of tumor-bearing mice.Methods BALB/C mouse model carring colorectal cancer was established.Thirty mice were divided into three groups randomly and managed respectively with intratumor injection of DEPC water, MIFsiRNA(0.15 nmol/g) and non-specific siRNA (0.15 nmol/g), respectively twice a week for consecutively 4 weeks.Drinking water, fodder consumed and body weight was recorded daily, and tumor volume was measured once a week.Mice were sacrificed after four weeks.ELISA and immunohistochemistry were used to detect the expression of MIF in serum and in tumor tissues.Spectrophotometric detection was used to detect caspase-3 protein.TUNEL was used to detect apoptotic cells.Results MIF expression in serum in MIFsiRNA group was lower than the other two groups [(22 ± 6) ng/ml vs (32 ± 8) ng/ml and (33 ± 8) ng/ml, P ＜ 0.01]; MIF expression in tissues was less than the other two groups [(85 ± 20) /500 vs.(423 ± 23) /500 and (442 ± 31) /500, P ＜ 0.01]; Tumor was smaller than the other two groups at third and fourth week (P ＜ 0.01) ; Tumor weight was significantly less than the other two groups [(1.93 ±0.21) g vs (4.40 ±0.30) g and (5.25 ±0.44) g, P＜0.01]; Mice in MIFsiRNA group were healthier than the other two groups as judged by water and fodder consumption (P ＜ 0.01 ) , while weight change was not significantly different among the three groups ( P ＞ 0.05 ).Caspase-3 protein in tissues was higher than the other two groups [(0.74 ±0.06) μg vs (0.57 ±0.08) μg and (0.56 ±0.02) μg, P ＜0.01]; Apoptosis cells in tissues were higher than the other two groups [(12 ± 2)/ 100 个vs 0 and 0, P ＜ 0.01].Conclusions Knockdowning MIF gene expression inhibits the growth of colorectal cancer xenografts and improves life quality of tumor-bearing mice, possibly by a mechanism in which MIFsiRNA activates caspase-3 promoting cell apoptosis.

Aim To explore the effect of microRNAs on the differentiation of 3T3-L1 adipocytes and the expression of adipo-related gene-fatty acid binding protein during the adipocyte differentiation.Methods adipo-related microRNAs during 3T3-L1 adipocyte differentiation were screened and identified by micorRNA microarray.Constructed high-expression plasmids of the adipo-related microRNAs,were transfected into the 3T3-L1 preadipocytes by lipofectamine.While the effect of adipo-related microRNAs on the course of 3T3-L1 adipocyte differentiation was observed,the protein and mRNA expression level of fatty acid binding protein(FABP4)were analyzed by Western blot and RT-PCR during 3T3-L1 adipocyte differentiation.Results The expression profiles of microRNAs have significant changed during 3T3-L1 adipocyte differentiation,in which 35 microRNAs among them down-relation,the most lowly expression is miR-24;17 microRNAs among them up-relation,the most highly expression is miR-21.MiR-24 significantly inhibited adipocyte differentiation and maturity,while miR-21 have no significant effect.MiR-24 significantly inhibited the expression of FABP4,but had no effect on the level of its mRNA;miR-21 had no effect on the expression of protein and mRNA of FABP4.Conclusion There exist adipogenic-related microRNAs during 3T3-L1 adipocyte differentiation; miR-24 play an important role in the regulation of 3T3-L1 preadipocyte differentiation into adipocyte and the(FABP4)protein expression.

The levels of macrophage migration inhibitory factor (MIF) in peripheral blood mononuclear cell (PBMC) and serum in patients with Hashimoto's thyroiditis (HT) were detected by real-time PCR and ELISA,respectively.The results revealed that the expression of MIF mRNA in PBMC ( Z =-4.276,P＜0.01 ) and protein level in serum ( Z=-5.358,P＜0.01 ) were increased in HT patients,and positively correlated with thyroid specific autoantibodies and TSH levels.