MicroRNA-22-3p Regulates the Expression of Kruppel-like Factor 6 to Affect the Cardiomyocyte-like Differentiation of Bone Marrow Mesenchymal Stem Cell / 中国医学科学院学报

Objective To explore the effect of microRNA-22-3p (miR-22-3p) regulating the expression of Kruppel-like factor 6 (KLF6) on the cardiomyocyte-like differentiation of bone marrow mesenchymal stem cell (BMSC). Methods Rat BMSC was isolated and cultured,and the third-generation BMSC was divided into a control group,a 5-azacytidine(5-AZA)group,a mimics-NC group,a miR-22-3p mimics group,a miR-22-3p mimics+pcDNA group,and a miR-22-3p mimics+pcDNA-KLF6 group.Real-time fluorescent quantitative PCR (qRT-PCR) was carried out to determine the expression of miR-22-3p and KLF6 in cells.Immunofluorescence staining was employed to detect the expression of Desmin,cardiac troponin T (cTnT),and connexin 43 (Cx43).Western blotting was employed to determine the protein levels of cTnT,Cx43,Desmin,and KLF6,and flow cytometry to detect the apoptosis of BMSC.The targeting relationship between miR-22-3p and KLF6 was analyzed by dual luciferase reporter gene assay. Results Compared with the control group,5-AZA up-regulated the expression of miR-22-3p (q=7.971,P<0.001),Desmin (q=7.876,P<0.001),cTnT (q=10.272,P<0.001),and Cx43 (q=6.256,P<0.001),increased the apoptosis rate of BMSC (q=12.708,P<0.001),and down-regulated the mRNA (q=20.850,P<0.001) and protein (q=11.080,P<0.001) levels of KLF6.Compared with the 5-AZA group and the mimics-NC group,miR-22-3p mimics up-regulated the expression of miR-22-3p (q=3.591,P<0.001;q=11.650,P<0.001),Desmin (q=5.975,P<0.001;q=13.579,P<0.001),cTnT (q=7.133,P<0.001;q=17.548,P<0.001),and Cx43 (q=4.571,P=0.037;q=11.068,P<0.001),and down-regulated the mRNA (q=7.384,P<0.001;q=28.234,P<0.001) and protein (q=4.594,P=0.036;q=15.945,P<0.001) levels of KLF6.The apoptosis rate of miR-22-3p mimics group was lower than that of 5-AZA group (q=8.216,P<0.001).Compared with the miR-22-3p mimics+pcDNA group,miR-22-3p mimics+pcDNA-KLF6 up-regulated the mRNA(q=23.891,P<0.001) and protein(q=13.378,P<0.001)levels of KLF6,down-regulated the expression of Desmin (q=9.505,P<0.001),cTnT (q=10.985,P<0.001),and Cx43 (q=8.301,P<0.001),and increased the apoptosis rate (q=4.713,P=0.029).The dual luciferase reporter gene experiment demonstrated that KLF6 was a potential target gene of miR-22-3p. Conclusion MiR-22-3p promotes cardiomyocyte-like differentiation of BMSC by inhibiting the expression of KLF6.

Genes Expression in the Early Stage of Acute Renal Ischemia-reperfusion Injury in Rats / 法医学杂志

OBJECTIVES@#To study the differential genes expression in the early stage of acute renal ischemia-reperfusion injury and explore potential molecular mechanisms.@*METHODS@#The ischemia-reperfusion model was made via clamping renal artery of rat. The microarray detection and bioinformatics analyzing of the genes expression were performed. Differentially expressed genes were screened and related cellular activities and signaling pathways were analyzed in early stage of acute kidney injury. Meanwhile, molecules closely relative to acute kidney injury were explored by establishing a biological network of the differentially expressed genes, and the results were verified by real-time PCR.@*RESULTS@#A total of 151 genes showed differential expression in this study, including 132 up-regulated and 19 down-regulated genes. Cell proliferation, cytokines mediated signaling transduction and immune responses were greatly enriched by GO and KEGG analysis. The results of real-time PCR showed that compared with control groups, three selected genes （ANXA1, PHLDA1 and KLF6） which related to the acute kidney injury had an obvious differential expression in the early stage of disease. The multiple of increase was essentially the same as the multiple detected by microarray.@*CONCLUSIONS@#This study shows differential gene expression profile, related biological processes and signaling pathways involved in the early stage of acute kidney injury. ANXA1, PHLDA1 and KLF6 may play a role in the pathogenesis of acute kidney injury.

Transcriptional activation of TMSG-1 by complex of KLF6 and Sp1 / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the regulatory mechanism of the transcription of tumor metastasis suppressor gene TMSG-1.</p><p><b>METHODS</b>Luciferase reporter assay and site-directed mutagenesis were used to analyze the regulatory region of TMSG-1. Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) were carried out to verify the interaction of KLF6 and Sp1 with the regulatory region of TMSG-1. Co-immunoprecipitation (CoIP) was performed to analyze the interaction between KLF6 and Sp1. TMSG-1 and wt-KLF6 mRNA expressions in cells with different metastatic capacities were quantitated by real-time PCR. Cell invasive capability was determined by Matrigel invasion assay.</p><p><b>RESULTS</b>A 63 bp inducible regulatory region (+59 bp - +123 bp) in exon 1 was identified by luciferase assay using reporter plasmids with a series of TMSG-1 regulatory region deletions. Mutations in KLF6/Sp1 binding sites of this region resulted in a decrease of luciferase activity, while cotransfection with KLF6 or Sp1 expressing plasmids led to a remarkable increase of luciferase activity. EMSA and ChIP demonstrated that KLF6 as well as Sp1 interacted with this region. CoIP also indicated a possible interaction between KLF6 and Sp1 proteins. In the highly metastatic cell sublines, a low level of wild type KLF6 was associated synchronously with a low TMSG-1 level. Prostate carcinoma cells overexpressing KLF6 exhibited a higher TMSG-1 level and a lower invasive capability.</p><p><b>CONCLUSIONS</b>Transcription factor complex of KLF6 and Sp1 may participate in the inducible transcriptional regulation of TMSG-1, and a decreased wild type KLF6 expression is likely associated with a low TMSG-1 level in the highly metastatic cell sublines.</p>

Effect of KLF6 and its splice variant KLF6V on proliferation and differentiation of human hepatocellular carcinoma HepG2 cells / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the roles of Kruppel-like factor 6 (KLF6) and its splice variant KLF6V on suppressing growth and inducing differentiation of human hepatocellular carcinoma hepG2 cells.</p><p><b>METHOD</b>KLF6V cDNA was amplificated by RT-PCR from human hepatocellular carcinoma (HCC) tissue and then sequenced. The recombinant vectors expressing KLF6 variant (KLF6V) were constructed using molecular clone technology based on established plasmid pcDNA3.1A(-)/wtKLF6. KLF6V or KLF6-transfected HepG2 cells were established after being screened with G418. Growth activity of HepG2/KLF6 or HepG2/KLF6V cells was detected by in vitro MTT assay. Expression of p21WAF1 or cyclin D1 protein was detected by Western blot, and expressions of AFP or ALB protein were measured by radioimmunoassay.</p><p><b>RESULTS</b>A novel alternatively spliced transcript of the human KLF6 gene was found and its sequencing revealed that the variant form of KLF6 lacked 126nt and its encoded protein products had a deletion of 42 aa near the COOH-terminal amino acid in comparison with full-length KLF6. Although KLF6 alternative splicing was present in both normal and cancerous tissues, expression of the KLF6 splice variants seemed to be up-regulated in HCCs tissues. The isoform of KLF6 proteins antagonized the ability of wild-type KLF6 to up-regulate p21 expression or down-regulate cyclin D1 expression and suppress HepG2 cell proliferation. KLF6 gene increased albumin production and decreased alpha fetoprotein production of the cells.</p><p><b>CONCLUSION</b>The isoform of KLF6 protein, present in HCC tissue, antagonizes the ability of wild-type KLF6 to suppress cell proliferation and induce cellular differentiation.</p>

Effects of rosiglitazone on Kruppul-like factor 6 (KLF6) signaling in the livers of rats with nonalcoholic fatty liver fibrosis / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To study the effects of rosiglitazone on Kruppule-like factor 6 (KLF6) and its target gene TGFâ1 during the development of nonalcoholic fatty liver fibrosis.</p><p><b>METHOD</b>Thirty-six Wistar rats were divided into three groups: a control group, a high fat model group and an intervention group. Their blood serum TG, FFA, AST, ALT, HA, LN and CIV were measured. Hepatic expressions of KLF6, TGFbeta1 and alpha-SMA were detected by RT-PCR and immunohistochemistry. The pathological features and the degree of liver fibrosis before and after the rosiglitazone intervention were also studied.</p><p><b>RESULTS</b>The contents of TG, FFA, AST, ALT, HA, LN and CIV, the expression of KLF6, TGFbeta1 and alpha-SMA mRNA, and the degree (score) of liver fibrosis at the 24th week in the model group were significantly higher than those in the control group (P<0.01) but they were lower in the rosiglitazone intervention group (P<0.05). The protein expression of a-SMA was also lower in the intervention group compared with that of the model group.</p><p><b>CONCLUSION</b>Rosiglitazone, to a certain extent, can inhibit KLF6-TGFbeta1 signal transduction by inducing expression of PPAR-gamma, and then inhibit the activation of hepatic stellate cells and minimize hepatic fibrosis.</p>

Expressions and clinical implications of kruppel-like factor 6 and APC in human colorectal carcinoma / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the expressions and clinical implications of kruppel-like factor 6(KLF-6) and APC in human colorectal carcinoma.</p><p><b>METHODS</b>The expressions of KLF-6 and APC in tumor and normal tissues from 32 patients with colorectal carcinoma were investigated by RT-PCR and immunohistochemical technique.</p><p><b>RESULTS</b>The expression rates of KLF-6 and APC mRNA were 37.5% and 34.3% in tumor tissue, 96.9% and 93.8% respectively in normal tissues (both P< 0.05). The expression rates of KLF-6 and APC protein were 28.1% and 25.0% in colorectal carcinomas, 81.3% and 84.43% respectively in normal tissues (both P< 0.05). There was a significant correlation between the expressions of KLF-6 and APC in colorectal carcinomas (P < 0.05). The expressions of KLF-6 and APC were significantly correlated with tumor differentiation, depth of infiltration, lymph node metastasis and clinical stage (P< 0.05).</p><p><b>CONCLUSION</b>Down-regulations of KLF-6 and APC might play an important role in the carcinogenesis, development, metastasis of human colorectal carcinoma.</p>

Effect of KLF6 on prostate cancer cell line PC-3 by transgenic method / 中华男科学杂志

<p><b>OBJECTIVE</b>To observe the effect of KLF6 on prostate cancer cell line PC-3 by transgenic method.</p><p><b>METHODS</b>We obtained KLF6 cDNA by RT-PCR method from the liver cell, transfected plasmid pEGFP-C, recombinated with KLF6 into PC-3 cells, and used them as a transfection group and a control group. MTT, flow cytometer and immunocytochemical methods were used to observe the effect of anti-oncogene wild type KLF6 on prostate cancer cell line PC-3 by transgenic method for 48 hours.</p><p><b>RESULTS</b>After transfected into PC-3 cells, KLF6 enhanced growth suppression, (30.0 +/- 5.4)% in the transfection group and 0% in the control, P < 0.01, apoptosis, (24.3 +/- 2.3)% in the transfection group and (5.2 +/- 0.7)% in the control, P < 0.01, the down-regulation of the expression of cyclin D1, (25.3 +/- 3.7)% in the transfection group and (38.5 +/- 4.6)% in the control, P < 0.05 and Bcl-2, (18.7 +/- 3.2)% in the transfection group, and (41.8 +/- 5.9)% in the control, P < 0.01 in PC-3 cells. It also decreased the ratio of the cell phase G2/M, increased the ratio of G0/G1 from (58.6 +/- 7.3)% in the control to (80.0 +/- 9.8)% in the transfection group, P < 0.05.</p><p><b>CONCLUSION</b>PC-3 cells transfected with wild type KLF6 can enhance its growth suppression and apoptosis. It shows great potential for the gene therapy of androgen-independent carcinoma of the prostate.</p>

Mutations of the tumor suppressor Kruppel-like factor 6 (KLF6) gene in hepatocellular carcinoma and its effect of growth suppression on human hepatocellular carcinoma cell line HepG2 / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To explore the mutated KLF6 gene in hepatocellular carcinoma (HCC) and to characterize its behavior in human hepatocellular carcinoma cell line HepG2.</p><p><b>METHODS</b>We analyzed the DNA isolated from 23 hepatocellular carcinoma tissues and their adjacent nontumor tissues by polymerase chain reaction (PCR). Direct sequencing was used to establish the incidence of mutation in exon2 of the KLF6 gene. Loss of growth suppressive function of the HCC-derived KLF6 mutants was characterized by in vitro analyzing alteration of cell cycle and MTT assay. Expression of p21WAF1, a possible downstream gene of KLF6, was detected in human hepatocellular carcinoma cell line HepG2 transiently transfected with KLF6 genes.</p><p><b>RESULTS</b>Mutations of KLF6 were found in 2 of the 23 (8.7%) hepatocellular carcinomas. The two mutations were located in the transactivation domain and one of them resulted in single amino acid substitution of TGG (W) by GGG (G) at codon 162. Unlike the wild-type KLF6, cancer-derived KLF6 mutants neither suppressed growth nor induced p21WAF1 following transfection into culture cells.</p><p><b>CONCLUSIONS</b>Mutations of the KLF6 gene may play a role in the pathogenesis of HCC, but are not the dominating mechanism resulting in inactivation of KLF6 functions. KLF6 suppresses hepatocellular carcinoma cell proliferation partly through upregulating expression of the p21WAF1 gene.</p>

Inactivation of the tumor suppressor Krüppel-like factor 6 (KLF6) by mutation or decreased expression in hepatocellular carcinomas / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

<p><b>BACKGROUND AND AIM</b>The Krüppel-like transcription factor KLF6 is a novel tumor-suppressor gene. It was inactivated in human prostate cancer and other tumors tissue, as the result of frequent mutation and loss of heterozygosity (LOH). However, there is no data reporting the levels of KLF6 both mRNA and protein in hepatocellular carcinomas (HCCs). We therefore detected mutations and expression of KLF6 in HCC tissues and further observed the effect of it on cell growth in HCC cell lines.</p><p><b>METHODS</b>We analyzed the exon-2 of KLF6 gene by direct DNA sequencing, and detected the expression of KLF6 by RT-PCR and Western blot in 23 HCC tissues and corresponding nontumorous tissues. Loss of growth suppressive effect of the HCC-derived KLF6 mutant was characterized by in vitro growth curves plotted, flow cytometry and Western blotting.</p><p><b>RESULTS</b>KLF6 mutations were found in 2 of 23 HCC tissues and one of mutations was missense. Expression of KLF6 mRNA or protein was down-regulated in 8 (34.7%) or 9 (39.1%) of 23 HCC tissues. Wild-type KLF6 (wtKLF6) inhibited cellular proliferation and prolonged G1-S transition by inducing the expression of p21WAF1 following stable transfection into cultured HepG2 cells, but tumor-derived KLF6 mutant (mKLF6) had no effects.</p><p><b>CONCLUSION</b>Our findings suggest that KLF6 may be involved in pathogenesis of HCC.</p>

KLF6mRNA expression in primary hepatocellular carcinoma / 华中科技大学学报（医学）（英德文版）

To investigate the expression of KLF6mRNA in primary hepatocellular carcinoma (HCC), nomal liver tissues and the tissues adjacent to the cancers, reverse-transcription polymerase chain reaction (RT-PCR) was employed to investigate the expression of the KLF6 gene in HCC, the corresponding adjacent non-cancerous tissues and normal liver tissue. Our results showed that an amplified fragment of 427 bp DNA was detected in 18 of 19 (94.7%) adjacent non-cancerous tissues and normal liver tissue, and in 12 (85.7%) of 14 HCC. There were no significant differences in the levels of KLF6 mRNA between normal liver and liver tumors (P>0.05). It is concluded that KLF6 mRNA is generally expressed in HCC.