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ObjectiveTo study the underlying mechanism of Liuwei Dihuangwan in inhibiting triple-negative breast cancer through mitogen-activated protein kinase kinase kinase 1 （MAPKKK1） and Krüppel-like factor 4 （KLF4）. MethodFour hundreds SPF female Kunming mice aged 11.5 months were palpated once every 3 days. The model mice of spontaneous tumors were randomly divided into a model group （normal saline）， a paclitaxel group （0.025 g·kg-1·d-1， ip， 21 days）， and high-， medium- and low-dose Liuwei Dihuangwan groups （7.2， 3.6， 1.8 g·kg-1·d-1， ig）. Tumor tissues were separated until the moribund stage. The tumor volume and weight were measured， and the tumor inhibition rate and the survival time of the tumor mice were calculated （after 6 months， tumor-free mice were assigned into the normal group）. SPF SD rats were selected to prepare serum samples containing Liuwei Dihuangwan of different concentrations for cell culture， and MAPKKK1 in MDA-MB-231 cells was silenced. The protein expression of MAPKKK1 and KLF4 was detected by immunofluorescence and Western blot. ResultThe in vivo experimental results showed that compared with the conditions of the normal group， the protein expression of MAPKKK1 and KLF4 in tumor tissues of the model group dropped （P<0.01）. Compared with the model group， all medication groups showed reduced tumor volume and weight （P<0.05， P<0.01）， increased tumor inhibition rate， prolonged survival time of tumor mice （P<0.05）， and increased protein expression of MAPKKK1 （P<0.01）. Additionally， the paclitaxel group and the high-dose Liuwei Dihuangwan group exhibited increased protein expression of KLF4 （P<0.01）. The in vitro experiments showed that compared with the conditions of the normal group， the fluorescence intensities of MAPKKK1 and KLF4 in MDA-MB-231 cells in all medication groups were potentiated， and the protein expression of MAPKKK1 in the paclitaxel group and the high- and medium-dose Liuwei Dihuangwan groups， and the protein expression of KLF4 in the paclitaxel group and high-dose Liuwei Dihuangwan group increased （P<0.01）. After silencing of MAPKKK1， compared with the conditions of the negative plasmid group （unsilenced MAPKKK1）， the fluorescence intensities of MAPKKK1 and KLF4 and the protein expression decreased in the RNAi-27 positive plasmid group （silenced MAPKKK1） （P<0.05， P<0.01）. Compared with the RNAi-27 positive plasmid group， all medication groups had enhanced fluorescence intensities of MAPKKK1 and KLF4 and protein expression to different degrees （P<0.05， P<0.01）. ConclusionLiuwei Dihuangwan can inhibit the growth of triple-negative breast cancer， and the underlying molecular mechanism is related to the up-regulation of MAPKKK1 and activation of KLF4 expression.
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[Abstract] Objective To explore the relationship between Kruppel-like factor 4 (KLF-4) and E-cadherin in human peritoneal mesothelial cells (HPMCs), and the expression and function of KLF-4 in the animal model of peritoneal fibrosis induced by high glucose peritoneal dialysate. Methods Co-transfection in HPMCs with the plasmid of KLF-4 and the bind site or mutant in the promoter region of E-cadherin, and then the luciferase activity was measured of the each bind site and its matched mutants to estimate whether KLF-4 can combine with the bind site in the promoter region of E-cadherin; Chromatin immunocoprecipitation (CHIP) was exploited to verify if KLF-4 can combine with the bind site in the promoter region of E-cadherin; Real-time PCR and Western blotting were performed to detect the expression of E-cadherin at the bind site and matched mutants of b, d, f and g. Thirty SD rats were randomly divided into saline group, peritoneal dialysate group and experimental group (10 each). Rats in saline group were given intraperitoneal injection with 0.9% NaCl, in peritoneal dialysate group were given with 4.25% high glucose peritoneal dialysate, and in experimental group were given via tail vein with 4.25% high glucose peritoneal dialysate and the mixture of KLF-4 plasmid suspension containing ultrasound microbubble. To observe the peritoneal tissue thickness of the 3 groups of rats by Hematoxylin and Eosin staining. Masson trichrome staining was performed to detect the deposition of collagen fibers in peritoneal tissue of the 3 groups of rats. Immunohistochemistry was used to detect the expression level of KLF-4, E-cadherin, α-SMA and fibronectin (FN) in peritoneal tissue of the 3 groups of rats. Results Promoter luciferase reporter gene and CHIP results showed that KLF-4 can combine with the bind site in the promoter region of E-cadherin in HPMCs. Real-time PCR and Western blotting showed that KLF-4 can positively regulate the expression of E-cadherin. HE staining showed that the peritoneal tissue was obviously thickened in rats of peritoneal dialysate group [(105.91±12.0) μm] than in rats of saline group [(20.89±5.39) μm] and of experimental group [(23.05±6.07) μm] with statistical significance (P0.05). Masson staining showed that the deposition of collagen fiber significantly increased in peritoneal dialysate group (0.89±0.09) than in saline group (0.19±0.03) and experimental group (0.15±0.06) with statistical significance (P0.05). Immunohistochemistry results showed that the expressions of KLF-4 and E-cadherin were obviously lower in peritoneal dialysate group (0.27±0.09, 0.31±0.03) than in saline group (0.79±0.19, 0.83±0.13) and experimental group (0.85±0.11, 0.76±0.11) with statistically significant difference (P0.05). In contrast, the expressions of α-SMA and FN were evidently higher in peritoneal dialysate group (0.83±0.09, 0.63±0.09) than in saline group (0.22±0.08, 0.30±0.07) and experimental group (0.19±0.05, 0.11±0.03) with statistically significant difference (P0.05). Conclusion KLF-4 may positive regulate the expression of E-cadherin by combining with the bind site in the promoter region of E-cadherin, and inhibit the peritoneal fibrosis induced via high glucose peritoneal dialysate.
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Objective: To investigate the effect of Krüppel-like factor 4 (KLF4) on the expression of miR-106a and their interaction on the invasive activity of human gastric cancer cells. Methods: The JASPAR database was used to screen the transcriptional factor combined with miR-106a promoter. KLF4 over-expression vector KLF4-pcDNA and miR-106a reporter gene pmiR-106a-WT/MUT-luc were both constructed, and the dual luciferase reporter assay was used to detect the effect of KLF4 on the activity of miR-106a promoter. Forty specimens of human gastric cancer and their adjacent formalin-fixed paraffin-embedded (FFPE) specimens were collected, and Real-time PCR and immunohistochemistry were both used to detect the expression of KLF4. Human gastric cancer cell line BGC-823 was divided into four groups: miR-106a mimic, mimic NC, KLF4+pcDNA, and pcDNA basic. Transwell assay was employed to detect the invasive ability of the gastric cancer cells after four different treatments. Results: Dual luciferase reporter assay indicated that KLF4-pcDNA could antagonize the activity of miR-106a promoter, which suggested that the activity of pmiR-106a-WT-luc luciferase was inhibited (pmiR-106a-WT+pcDNA-basic compared with pmiR-106a-WT+pcDNA-KLF4, P0.05). FFPE samples showed that the relative expression of KLF4 in gastric cancer was 0.69±0.59, which significantly differed from that in adjacent paracancerous tissues (P<0.001). The expression of KLF4 was correlated with differentiation degree, lymph node metastasis, and infiltration depth of human gastric cancer (P<0.05). The positive expression of KLF4 was mainly located in the nucleus and cytoplasm of gastric mucosal epithelial cells. Transwell essay showed that the number of invasive cells in the four different treatment groups was not entirely the same (P<0.001): 89.00±14.85 for miR-106a mimic, 50.90±17.94 for mimic NC, 37.70±12.60 for KLF4+pcDNA, and 66.20±3.19 for pcDNA basic. Conclusion: Transcription factor KLF4 at least has direct binding with miR-106a promoter in vitro, which may be involved in the invasion and metastasis process of gastric cancer cell by negatively regulating the expression of miR-106a at the upstream transcription level.
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Objective To explore the effect of Kruppel like factor 4 (KLF4) on epithelial-to-mesenchymal transition and invasion ability of pancreatic cancer.Methods The expression of KLF4 in 70 pancreatic cancer tissues and 10 normal pancreatic tissues was detected by immunohistochemistry,and the correlations between KLF4 expression and pathological characteristics were analyzed.Small hairpin RNA targeting KLF4 (sh-KLF4) and negative control shRNA were constructed.After the transfection of shRNA,qRT-PCR and western blot were used to detect the mRNA and protein expression of KLF4,E-cadherin and vimentin,and cell scratch-wound assay and transwell assay were utilized to determine the ability of invasion and metastasis.Results KLF4 expression (47.1％) was lower in pancreatic cancer tissues compared with normal pancreatic tissues (80.0％),and negatively correlated with cell differentiation,tumor stage and distant metastasis.Down-regulated KLF4 expression in PANC1 cell caused decreased mRNA and protein expression of E-cadherin (F =25.71,P =0.0011) and increased mRNA and protein expression of vimentin (F =24.95,P=0.0012).Knockdown of KLF4 in PANC1 cell promoted the transition from epithelial morphology to mesenchymal morphology,and enhanced the healing ability (F =47.82,P ＜ 0.001),migration (F =53.68,P=0.0001) and invasion (F=27.65,P=0.0009).Conclusions Knockdown of KLF4 can promote EMT and enhance the invasion ability of pancreatic cancer.
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Objective To screen the critical genes related to the development of esophageal squamous cell carcinoma ( ESCC ) by weighted gene co-expression network analysis ( WGCNA ) and to verify by experiments.Methods Gene expression data of ESCC were downloaded from gene expression omnibus (GEO) database based on gene chip platform ( GPL) 570, GPL571, GPL96/97 or GPL14613 platform, respectively. Meanwhile, the obtained differentially expressed genes together with gene expression data of 81 ESCC patients from the cancer genome atlas ( TCGA ) and clinical data were analyzed by WGCNA to set up co-expression networks including mRNA and microRNA ( miRNA ) . The expression of miRNA in ESCC tissues and paracancerous tissues was examined by quantitative real-time polymerase chain reaction ( RT-PCR ) .And the expression of target protein Kruppel like factor 4 ( KLF4 ) and desmocollin 2 ( DSC2 ) were detected by immunohistochemistry .After ESCC cell line ECA-109 cells were transfected with miRNA-92b-3p mimic, cell cycle was tested by flow cytometry ,the cell invasion and migration ability was measured by Transwell chamber assay and scratch-wound assay.The expression of KLF4 and DSC2 was observed by confocal laser scanning microscopy and Western blotting .The target genes were verified by luciferase assay .T-test, rank sum test, chi-square test and Pearson correlation analysis were performed for statistical analysis .Results A total of 4023 differential expression gene ( DEG) and 328 differential expression miRNA ( DEM) were screened and 11 gene modules were set up by WGCNA .Among them, the brown modules were negatively associated with tumor grade and T stage (r=-0.340 and -0.268, P=0.002 and 0.016).Meanwhile, has-miR-92b and the potential target genes KLF4 and DSC2 were all in the brown module .Furthermore, the results of RT-PCR showed the expression of miRNA-92b-3p in ESCC tissues was higher than that in paracancerous tissues (3.052(1.652, 5.371) vs.0.985(0.558, 2.032)), and the difference was statistically significant (Z=-4.021,P<0.01). The results of immunohistochemistry demonstrated that the positive rates of KLF 4 and DSC2 in ESCC tissues were 43.3％(13/30) and 20.0％(6/30), respectively, which were lower than those of paracancerous tissues (70.0％(21/30) and 63.3％(19/30)), and the differences were statistically significant (χ2 =4.344 and 1.589, both P<0.05).After ECA-109 cells were transfected with miRNA-92b-3p mimics, the percentage of cells at G0/G1 phase decreased ((63.71 ±2.83)％vs.(54.62 ±4.00)％) and the percentage of cells at the S phase and G2/M phase increased ((31.81 ±2.88)％vs.(41.20％±2.87)％, and (3.87 ±1.75)％vs. (8.10 ±1.71)％, respectively), and the differences were statistically significant (t =3.215, 4.000 and 2.998;P=0.032, 0.016 and 0.040).The invasion and migration ability of the cells were significantly improved (79.67 ±27.54 vs.280.33 ±46.18, (69.72 ±3.91)％ vs.(84.90 ±5.25)％), and the differences were statistically significant (t=6.465 and 4.019, P=0.003 and 0.016).The results of Western blotting indicated that, compared with control mimic group , the expression of KLF4 and DSC2 was both dramatically downregulated after transfected with miRNA-92b-3p mimics transfected (1.00 ±0.23 vs.0.42 ±0.03, 1.00 ±0.20 vs.0.55 ± 0.21), and differences were statistically significant (t=4.470 and 5.493, P=0.042 and 0.032).The results of luciferase assay demonstrated that miRNA-92b-3p could directly bind KLF4 and DSC2. Conclusion WGCNA is an efficient systemic biological approach by which miRNA-92b-3p is identified as a new cancer-promoting gene .
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Objective To investigate whether microRNA-34a (miR-34a) participates in lipopolysaccharide (LPS) mediated sepsis related renal function impairment via Kruppel-like factor 4 (KLF4). Methods Thirty healthy male Sprague-Dawley (SD) rats, weighing 180-200 g, were randomly divided into two groups: control group and model group, with 15 rats in each group. The SD rats from model group were injected with LPS 7.5 mg/kg to induce sepsis related renal function impairment model, the SD rats from control group were injected with normal saline. The serum creatinine concentration (SCr) and blood urine nitrogen (BUN) content was detected by multifunction biochemical analyzer; the morphological changes of renal tissue were observed by hematoxylin and eosin stain (HE) staining; the expression of miR-34a and KLF4 gene in plasma and renal tissue were detected by real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR); the protein expression of KLF4 in renal tissue was detected by Western Blot; the target gene of miR-34a was verified by double luciferase reporter gene analysis. Results Compared with control group, inflammatory cell infiltration in renal tissue was increased in model group, the SCr and BUN were significantly increased [SCr (μmol/L): 142.5±10.6 vs. 46.4±5.6, BUN (mmol/L): 31.6±6.2 vs. 8.5±1.2, both P < 0.01], the gene expression of miR-34 in plasma and renal tissue were significantly increased (2 -ΔΔCt: 2.26±0.11 vs. 1.14±0.05 in plasma, 4.23±0.12 vs. 1.12±0.04 in renal tissue, both P < 0.01), the gene and protein expressions of KLF4 were significantly decreased [KLF4 gene (2 -ΔΔCt): 0.52±0.03 vs. 1.21±0.06, KLF4 protein (A value): 0.72±0.03 vs. 1.05±0.04, both P < 0.01], which indicated that kidney injury occurred in rats. Pearson correlation analysis showed that plasma miR-34a was positively correlated with SCr and BUN (r value were 0.678, 0.721, respectively, both P < 0.05). Double luciferase reporter assay confirmed that KLF4 was the target gene of miR-34a. Conclusion The miR-34a participates in LPS mediated sepsis related renal function impairment via KLF4.
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Objective To construct and identify a lentiviral vector carrying mouse Krüppel-like factor 4 (KLF4) gene, and establish RAW264.7 cell line of peritoneal macrophages that over-expressed KLF4. Methods KLF4 gene was cloned using the measure of polymerase chain reaction (PCR). Then the recombinant transfer vector pLVX-KLF4 (pLVX-KLF4-mCMV-ZsGreen-PGK-Puro) was constructed. The pLVX-KLF4 was confirmed through PCR, restriction enzyme digestion and sequencing. The correct recombinant transfer vector together with its two helper virus vectors (psPAX2 and pMD2.G) were cotransfected into the 293T cells by Lipofectamine? 3000. The supernatant of 293T was harvested to infect RAW264.7 cells. Flow cytometry (FCM) was used to test the viral titer of the expression level of green fluorescent protein. The expression of KLF4 mRNA in RAW264.7 cells was measured by real-time PCR. Results The restriction enzyme digestion, PCR and sequencing confirmed that the transfer lentiviral vector pLVX-KLF4 was constructed successfully. KLF4 mRNA was over-expressed in Lenti-KLF4 transfected RAW264.7 cells than that of wild type RAW264.7 cells (P<0.05). In transfected RAW264.7 cells, KLF4 mRNA was over-expressed (P<0.05). The recombinant lentivirus of KLF4(Lenti-KLF4)titer was 2.05×108 TU/mL measured by FCM.The flow cytometry results showed that the S phase fraction was prolonged and G0/G1 was arrested in the over-expressed KLF4 of RAW264.7 cells. The EdU showed that the up-regulated expression of KLF4 gene stimulated the proliferation of RAW264.7 cells. Conclusion The recombinant lentiviral vector, which can effectively express KLF4 mRNA, has been successfully constructed. The up-regulated KLF4 gene may increase the proliferation of RAW264.7 cells.
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Objective To evaluate the effect of microRNA-92a (miR-92a) on regulating cell proliferation by targeting Krüppel-like factor 4 (KLF4) in colon cancer.Methods The miR-92a expressions in 21 colon cancer tissues and matched normal tumor-adjacent tissues and 4 colon cancer cells (HT29,SW480,SW620,HCT116) were detected using quantitative real-time polymerase chain reaction (qRT-PCR).Models of over-expression and suppression of miR-92a were established by transient transfection of miR-92a-3p mimic to HCT116 and transient transfection of miR-92a-3p inhibitor to SW620,respectively.Cell proliferation activity was detected by the CCK-8 colorimetry method,cell cycles were detected by flow cytometry,KLF4 protein expression was detected by Western blotting,and cell luciferase activity was detected by the dual luciferase reporter gene experiment.Results The expression level of miR-92a in colon cancer tissues was (0.648 ± 0.489) fmol/μg total RNA,significantly higher than that in matched normal tumor-adjacent tissues [(0.064 ± 0.062) fmol/μg total RNA],with statistically significant difference (t =-5.420,P ＜ 0.001).In 4 colon cancer cell lines,the miR-92a expression level in HCT116 cells was the lowest,and highest in SW620 cell.When the expression of miR-92a was up-regulated,the cell proliferation activity of 72 h in HCT116 cells was higher than that in the negative control group (0.919 ±0.014 vs.0.765 ± 0.025),with statistically significant difference (t =-9.309,P =0.001),the proportion of S phase cells was also significantly increased [(41.670 ±0.461)％ vs.(38.703 ±0.554)％,t =-7.127,P =0.002),and KLF4 protein expression was decreased (0.460 ± 0.048 vs.0.758 ± 0.109,t =22.865,P =0.028).When the expression of miR-92a was down-regulated,the cell proliferation activity of 72 h in SW620 cells was lower than that in the negative control group (0.608 ± 0.011 vs.0.713 ± 0.005),with statistically significant difference (t =15.920,P ＜ 0.001),while the proportion of S phase cells was decreased [(31.935 ± 0.365) ％ vs.(34.955 ± 0.465) ％,t =8.849,P =0.001],and KLF4 protein expression was increased (0.694 ± 0.121 vs.0.479 ± 0.044,t =-5.246,P =0.034).KLF4 3'UTR wild-type dual luciferase report plasmids were co-transfected with miR-92a-3p mimic to HCT116 cell,and dual luciferase assay showed that miR-92a slightly repressed firefly luciferase actively,but the difference was not statistically significant (t =0.878,P =0.429).There was a negative correlation between the expression of miR-92a and the expression of KLF4 protein in colon cancer tissues,but with no statistical significance (r =-0.163,P =0.699).Conclusion miR-92a is highly expressed in colon cancer tissues.It can promote colon cancer cells proliferation via enhancement of the cell cycle transition of G0-G1 phase to S phase.Up-expression of miR-92a may play a role in down-regulating the expression of KLF4 protein in colon cancer cells.However,KLF4 is not a direct target gene of miR-92a.
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Objective · To study the regulation of hsa-miRNA124-3p on the proliferation and migration of human lung cancer NCI-H460 cells and its mechanism. Methods · Four pairs of lung cancer and para-carcinoma tissues were harvested in clinical and measured for hsa-miRNA124-3p and Krüppellike factor 4 (KLF4) levels. The theoretical binding site of hsa-miRNA124-3p in 3'-UTR of KLF4 was predicted by bioinformatics, and validated by luciferase report assay. NCI-H460 cells were transfected with pshRNA-Sponge-miRNA124 or pshRNA-KLF4, and 48 hours later, the proliferation of NCI-H460 cells after genetic intervention was assayed by the MTT method, and cell migration ability was observed by streak method. Results · For all four pairs of samples tested, hsa-miRNA124-3p was higher in the cancer tissues than in the adjacent tissue (P0.05). The data of cell migration assay showed that the changes of cell migration ability were the same as proliferation activity of the cells in groups 72 h after transfection. Conclusion · Hsa-miRNA124-3p increases the proliferation and migration in NCI-H460 cells via suppressing the expression of KLF4, and reducing the content of miRNA124-3p in NC-H460 cells can inhibit cell proliferation and migration via upregulating KLF4 expression.
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Objective To explore the of miR-10b cordribution in patients with non-small cell lung cancer (NSCLC) and adjacent tissues,and to investigate the effect of miR-10b on the malignant change of lung cancer cell A549 by regulating the expression of Kruppel-like factor 4 (KLF4).Methods Fourty patients with NSCLC were selected with lung cancer and in miR-10b expression adjacent tissues of lung cancer cell A549 transfected miR-10b mimics,changes of CCK-8 assay were used to detect the proliferation of lung cancer cells;real time PCR and Western blot were used to examine the cell KLF4 mRNA and protein levels;soft agar colony formation assay was used to detect the expression of miR-10b on the proliferation of lung cancer cell A549 tumor malignant.Results miR-10b expression in lung cancer A549 cells and lung cancer tissue were higher than that of normal lung epithelial 16HBE cells and cancer adjacent tissues;overexpression of miR-10banalogue in A549 cells,KLF4 protein levels significantly decreased,KLF4 mRNA was not changed significantly;miR-10b expression significantly increased the growth of A549 cells.Conclusions The distribution of miR-10b in different cell types and tissues may be different,which may promote the proliferation and malignancy of lung cancer cells by inhibitingthe expression of KLF4.
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Objective@#To investigate the function and mechanism of zinc finger protein 750 (ZNF750) in esophageal squamous cell carcinoma (ESCC).@*Methods@#Xenograft in nude mice was applied to detect the tumorigenesis of ZNF750-depleted ESCC cells. Western blot was performed to observe the expression of downstream target protein of ZNF750 in ESCC cell lines and xenograft tumor tissues in which ZNF750 was knocked down. 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) assay was used to determine the proliferation of ZNF750 stably depleted cells after restoration of its target protein.@*Results@#The tumor weight of blank control, negative control and ZNF750 knockdown groups was 137±26 mg, 161±31 mg and 463±89 mg, respectively, with a statistically significant difference (P<0.01). The expressions of Kruppel-like factor 4 (KLF4) in ZNF750-depleted ESCC cells and its derived tumor tissue xenograft in nude mice were significantly down-regulated. Restoration of KLF4 in ZNF750 stably depleted cells significantly inhibited the cell proliferation (P<0.01).@*Conclusions@#ZNF750 may be a new tumor suppressor in the tumorigenesis of ESCC, and the inhibition of cell proliferation induced by ZNF750 may be partially through the regulation of KLF4 expression.
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Objective To explore the role of Kruppel-like factor 4 (KLF-4) in phenotypic transition of human peritoneal mesothelial cells (HPMCs) induced via high glucose. Methods HPMCs were induced by 50mmol/L glucose for 72 hours, the expressions of epithelium-cadherin (E-cadherin), KLF-4, α-smooth muscle actin (-SMA), connective tissue growth factor (CTGF) and miRNA-143 were detected by Real-time PCR and Western blotting, respectively. The treated cells were transfected with LVKLF-4 and inhibitor, the untreated cells were transfected with shRNA-KLF-4 and mimic. The mRNA and protein expressions of KLF-4, E-cadherin, α-SMA, CTGF and miRNA-143 were detected by Real-time PCR and Western blotting, respectively. Results Real-time PCR showed that the expression of E-cadherin decreased and of α-SMA, CTGF and miRNA-143 increased, but of KLF-4 not changed in high glucose treated cells. Western blotting showed that the expression of KLF-4 and E-cadherin decreased. Upregulating KLF-4 increased the expression of E-cadherin, but decreased the expression of α-SMA and CTGF. Down-regulating KLF-4 decreased the expression of E-cadherin, but augment the expression of α-SMA and CTGF. Conclusion High glucose may induce the down-regulation of KLF-4 protein, and SRF- miRNA-143-KLF-4 signal pathway axis may be involved in the process of HPMC phenotypic transition.
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[ ABSTRACT] AIM:To investigate the inhibitory effect of Am80 on neointima hyperplasia in carotid arteries after balloon injury and to observe the interaction between Krüppel-like factor 4 (KLF4) and retinoic acid receptorα(RARα). METHODS:Neointima hyperplasia in carotid arteries was observed by hemotoxylin and eosin staining.The expression of KLF4 and cyclin D1 was examined by immunostaining and Western blotting analysis.To detect the interaction between KLF4 and RARαin the vascular tissue, the injured arteries were harvested, and the protein extracts were prepared and subjected to co-immunoprecipitation assay.RESULTS:Compared with injured group, Am80 significantly reduced neointi-mal hyperplasia and the thickness ratio of intima to media.Am80 not only up-regulated KLF4 or RARαexpression in caro-tid arteries, but also increased the interaction between KLF4 and RARαat tissue levels.CONCLUSION:Am80 inhibits neointima hyperplasia in carotid arteries after balloon injury by promoting the interaction between KLF4 and RARα.
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Aim To observe the expressions of KLF4 in the myocardium of diabetic mice and their changes under Tongxinluo capsule intervention. Methods For-ty KK/Upj-Ay mice were randomly divided into diabet-ic model group(n=10)and diabetic model with Tongx-inluo(TXL low,middle,high) groups(n =10,respec-tively). C57BL/6 mice were selected as control group ( n=10 ) . At the end of the 3 th month the mice were sacrificed and were weighed. The fasting blood-glucose (FBG),glycosylated hemoglobin(HbA1c),triglyceride ( TG) ,total cholesterol ( TC ) and insulin ( FINS ) were measured to calculate HOMA-IR. Radioimmunoassay was used to measure serum TNF-αand IL-6 . The path-ological changes in the myocardium of mice were ob-served by HE staining. KLF4 mRNA was examined by Real-time PCR, while KLF4 and NF-κB protein were measured by Western blot. Results Compared to the control group,FBG,HbA1c,TG,TC,FINS,HOMA-IR, TNF-α and IL-6 in model group were markedly in-creased;the expressions of myocardial KLF4 were markedly decreased and the expression of nuclear NF-κB protein were markedly increased ( P 0. 05). Conclu-sions KLF4 may be involved in the development of myocardial injury during diabetes. Tongxinluo capsule can ameliorate the myocardial damage and improve the function of diabetic myocardium by up-regulating the expression of KLF4 and inhibiting the activation of NF-κB inflammatory signal pathway.
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s: Objective To explore the role of microRNA-206 in peripheral blood mononuclear cells (PBMC) in the pathogenesis and development of childhood asthma. Methods Twenty-seven asthmatic children and 25 healthy controls were enrolled in the study. Peripheral blood mononuclear cells were isolated in both healthy subjects and asthmatic children in acute attack and remission stages. Total RNAs were extracted from PBMC stimulated by PMA and ionomycin, and then the RNA was reversely transcribed into cDNA. The expressions of microRNA-206 and Kruppel-like factor 4 (KLF4) and IL-17 mRNA were detected by real-time quantitative PCR (qRT-PCR) method. Results There was signiifcant difference of microRNA-206 levels among asthmatic children in attack stage and in remission stage and normal controls (F=46.58~72.81, P=0.000). Through pair-wise comparison, the microRNA-206 levels of asthmatic children in attack stage were signiifcantly lower than those in remission stage and normal control groups (P0.05). Furthermore, a negative correlation was found between the expression of miR-206 and KLF4 (r=–0.66, P<0.01) and between the expression of miR-206 and IL-17 mRNA (r=–0.81, P<0.01) in asthmatic children in attack stage. A positive correlation was also found between KLF4 and IL-17 mRNA in asthmatic children in attack stage (r=0.70, P<0.01). Conclusions The expression of miR-206 is decreased in asthmatic children, and miR-206 might be involved in the pathogenesis and development of asthma.
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Objective To explore the role of miR-206 in peripheral blood mononuclear cells (PBMCs) of systemic lupus erythematosus (SLE) patients.Methods Human PBMCs were isolated by standard densitygradient centrifugation over Ficoll-Hypaque solution in SLE and healthy controls.Total RNAs were extracted from PBMCs which were stimulated by PMA and ionomycin,thenthe RNA was transcribed reversely into cDNA.The expression of miR-206 and Kruppel-like factor 4 (KLF4) and the orphan nuclear receptor RORγt mRNA was detected by real-time quantitative polymerase chain reaction (qRT-PCR) method.T test and Spearman's correlation test were used for statistical analysis.Results The expression of miR-206 in the PBMCs of SLE patients was significantly decreased compared with that of healthy controls (0.066±0.021 vs 0.143±0.059,t=3.136,P＜0.01).The levels of KLF4 and RORγt mRNAin the PBMCs of SLE patients were increased significantly than those of healthy controls (0.637 ±0.186 vs 0.104 ± 0.028,t=6.673,P＜0.01),(0.575±0.263 vs 0.065±0.014,t=7.386,P＜0.01).Furthermore,there was a negative correlation between the expression of miR-206 and KLF4 or RORγt mRNA in SLE patients (r=-0.627,P＜ 0.01),(r=-0.853,P＜0.01).Conclusion These results indicate that the augmented expression of KLF4 mRNA may be caused by the attenuated expression of miR-206,and the high level of KLF4 mRNA evokes the proportion of Thl7 cells in SLE patients.
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Objective To explore the role of microRNA-206 (miR-206)in peripheral blood mononuclear cells (PBMC)from rheumatoid arthritis (RA)patients.Methods 27 patients with RA and 25 healthy controls were enrolled into the current study.Human peripheral blood mononuclear cells (PBMCs)were isolated by standard density-gradient centrifugation over Ficoll-Hypaque solution in rheumatoid arthritis and healthy control volunteers.Total RNAs were extracted from PBMCs which were stimulated by PMA and ionomycin,then the RNA was transcribed reversely into cDNA.The expression of mi-croRNA-206 and Kruppel-like factor 4 (KLF4)and the orphan nuclear receptor RORγt mRNA was detected by real-time quantitative PCR (qRT-PCR)method.Student’s unpaired t-test and spearman correlation were used for statistica1 analysis. Results The expression of miR-206 in the PBMCs of RA patients was significantly decreased compared with that of the healthy controls (0.056±0.019 vs 0.138±0.057,t=3.103,P<0.01),The levels of KLF4 and RORγt mRNAin the PB-MCs of RA patients were increased significantly verves those of the healthy controls(0.604±0.183 vs 0.098±0.027,t=6.651,P<0.01;0.583±0.271 vs 0.069±0.018,t=7.438,P<0.01),Furthermore,a negative correlated between the ex-pression of miR-206 and KLF4 or RORγt mRNA in RA patients (r=-0.639,P<0.01;r=-0.842,P<0.01).Conclusion These results indicated that the augmented expression of KLF4 mRNA may be caused by the attenuated expression of miR-206,and the high level of KLF4 mRNA evokes the proportion of Th17 cells in RA patients.
ABSTRACT
Prostate cancer is the most frequently diagnosed malignancy and the second leading cause of cancer mortality among men in the United States. Accumulating evidence suggests that lysophosphatidic acid (LPA) serves as an autocrine/paracrine mediator to affect initiation, progression and metastasis of prostate cancer. In the current study, we demonstrate that LPA stimulates migration and proliferation of highly metastatic human prostate cancer, PC-3M-luc-C6 cells. LPA-induced migration of PC-3M-luc-C6 cells was abrogated by pretreatment of PC-3M-luc-C6 cells with the LPA receptor 1/3 inhibitor Ki16425 or small interfering RNA (siRNA)-mediated silencing of endogenous LPA receptor 1, implicating a key role of the LPA-LPA receptor 1 signaling axis in migration of PC-3M-luc-C6 cells. In addition, LPA treatment resulted in augmented expression levels of Kruppel-like factor 4 (KLF4), and siRNA or short-hairpin RNA (shRNA)-mediated silencing of KLF4 expression resulted in the abolishment of LPA-stimulated migration and proliferation of PC-3M-luc-C6 cells. shRNA-mediated silencing of KLF4 expression resulted in the inhibition of in vivo growth of PC-3M-luc-C6 cells in a xenograft transplantation animal model. Taken together, these results suggest a key role of LPA-induced KLF4 expression in cell migration and proliferation of prostate cancer cells in vitro and in vivo.
Subject(s)
Animals , Humans , Male , Cell Line, Tumor , Cell Movement , Cell Proliferation , Gene Silencing , Kruppel-Like Transcription Factors/genetics , Lysophospholipids/metabolism , Mice, Inbred BALB C , Prostate/metabolism , Prostatic Neoplasms/geneticsABSTRACT
BACKGROUND: Kruppel-like factor 4 (KLF4) is a transcription factor that regulates a diverse array of cellular processes, including development, differentiation, proliferation, and apoptosis. Although its function in keratinocytes has been widely studied, its exact role in psoriasis has not been elucidated. OBJECTIVE: We designed this study to investigate epidermal expression levels of KLF4 and the change in KLF4 expression after treatment in patients with psoriasis. METHODS: We compared the expression levels of KLF4 in the basal, suprabasal, and superficial epidermal layers, in psoriatic lesional, non-lesional, and normal skin, using an immunoreactivity intensity distribution index (IRIDI). In addition, we measured the change in KLF4 expression on the basis of the IRIDI and by reverse transcription polymerase chain reaction (RT-PCR) analysis after treatment. RESULTS: The combined IRIDI scores in psoriatic lesional skin were significantly higher than the scores in both non-lesional and normal skin. The psoriatic epidermis, particularly the suprabasal layer, showed a significantly increased IRIDI score compared to that of non-lesional and normal skin, which was significantly decreased after treatment. RT-PCR analysis exhibited a slight increase in KLF4 mRNA expression level after treatment; however, this increase was not significant. CONCLUSION: These data indicate that KLF4 could regulate epidermal proliferation and differentiation. Moreover, we believe that KLF4 may play an important role in the physiological reaction to counteract abnormal differentiation and proliferation of keratinocytes.
Subject(s)
Humans , Apoptosis , Epidermis , Keratinocytes , Polymerase Chain Reaction , Psoriasis , Reverse Transcription , RNA, Messenger , Skin , Transcription FactorsABSTRACT
BACKGROUND/AIMS: Kruppel-like factor 4 (KLF4) is an epithelial-specific transcription factor primarily expressed in the gastrointestinal tract that mediates growth arrest in the colonic epithelium. We tried to find whether KLF4 expression is associated with the progression and differentiation of colorectal cancer. METHODS: We detected KLF4 expression in 109 colorectal specimens (40 normal appearing mucosa, 7 adenomas, and 62 carcinomas) by immunohistochemistry using a tissue microarray. Western blot and RT-PCR analyses were also performed. RESULTS: The upregulation of KLF4 expression in carcinoma tissue was statistically significant (p0.05), while KLF4 protein expression correlated with the diagnostic stage (p<0.05). Furthermore, strong KLF4 staining was detected in 22.9% (11/48) and 0% (0/14) of well/moderately and poorly differentiated colorectal cancers, respectively. Our results clearly indicate that KLF4 protein expression significantly correlates with the degree of differentiation in colorectal cancers (p<0.05). KLF4 expression in RKO cells is also upregulated by butyrate, an inducer of differentiation. CONCLUSIONS: Downregulation of KLF4 expression may lead to more poorly differentiated tumors.