ABSTRACT
Diabetic wounds exhibit chronic inflammation and delayed tissue proliferation or remodeling, mainly owing to prolonged proinflammatory (M1) macrophage activity and defects in transition to prohealing/proremodeling (M2a/M2c; CD206+ and/or CD163+) macrophages. We found that topical treatment with ON101, a plant-based potential therapeutic for diabetic foot ulcers, increased M2c-like (CD163+ and CD206+) cells and suppressed M1-like cells, altering the inflammatory gene profile in a diabetic mouse model compared with that in the controls. An in vitro macrophage-polarizing model revealed that ON101 directly suppressed CD80+ and CD86+ M1-macrophage polarization and M1-associated proinflammatory cytokines at both protein and transcriptional levels. Notably, conditioned medium collected from ON101-treated M1 macrophages reversed the M1-conditioned mediumâmediated suppression of CD206+ macrophages. Furthermore, conditioned medium from ON101-treated adipocyte progenitor cells significantly promoted CD206+ and CD163+ macrophages but strongly inhibited M1-like cells. ON101 treatment also stimulated the expression of GCSF and CXCL3 genes in human adipocyte progenitor cells. Interestingly, treatment with recombinant GCSF protein enhanced both CD206+ and CD163+ M2 markers, whereas CXCL3 treatment only stimulated CD163+ M2 macrophages. Depletion of cutaneous M2 macrophages inhibited ON101-induced diabetic wound healing. Thus, ON101 directly suppressed M1 macrophages and facilitated the GCSF- and CXCL3-mediated transition from M1 to M2 macrophages, lowering inflammation and leading to faster diabetic wound healing.
ABSTRACT
Proton pump inhibitors (PPIs) are used for the long-term treatment of gastroesophageal disorders and the non-prescription medicines for acid reflux. However, there is growing concerns about PPI misuse, overuse and abuse. This study aimed to develop an animal model to examine the effects of long-term use of PPI in vivo. Twenty one Wistar rats were given omeprazole orally or intravenously for 30 days, and caerulein as a positive control. After euthanization, the serum and stool were collected to perform MS-based quantitative analysis of metabolites. We carried out 16S-based profiling of fecal microbiota, assessed the expression of bile acid metabolism regulators and examined the immunopathological characteristics of bile ducts. After long-term PPI exposure, the fecal microbial profile was altered and showed similarity to those observed in high-fat diet studies. The concentrations of several metabolites were also changed in various specimens. Surprisingly, morphological changes were observed in the bile duct, including ductal epithelial proliferation, micropapillary growth of biliary epithelium, focal bile duct stricture formation and bile duct obstruction. These are characteristics of precancerous lesions of bile duct. FXR and RXRα expressions were significantly reduced, which were similar to that observed in cholangiocarcinoma in TCGA and Oncomine databases. We established a novel animal model to examine the effects of long-term use of omeprazole. The gut microbes and metabolic change are consequences of long-term PPI exposure. And the results showed the environment in vivo tends to a high-fat diet. More importantly, we observed biliary epithelial hyperplasia, which is an indicator of a high-fat diet.
Subject(s)
Bile Ducts/drug effects , Gastrointestinal Microbiome/drug effects , Omeprazole/adverse effects , Proton Pump Inhibitors/adverse effects , Administration, Oral , Animals , Bile Duct Neoplasms/genetics , Bile Ducts/pathology , Cell Transformation, Neoplastic/drug effects , Cholangiocarcinoma/genetics , Cholestasis/chemically induced , Cholestasis/pathology , Feces/microbiology , Gastrointestinal Microbiome/physiology , Gene Expression Regulation/drug effects , Humans , Omeprazole/administration & dosage , Omeprazole/pharmacology , Proton Pump Inhibitors/administration & dosage , Proton Pump Inhibitors/pharmacology , RNA, Ribosomal, 16S , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , Rats, Wistar , Retinoid X Receptor alpha/genetics , Retinoid X Receptor alpha/metabolism , Tyrosine/blood , alpha-Tocopherol/bloodABSTRACT
BACKGROUND: Chemotherapy is used mainly to treat and control the progression of gynecological cancer. Bone marrow suppression, one of the adverse side effects of chemotherapy, may decrease immune function, increasing the risk of serious, fatal infections. PURPOSE: The aims of this study were to evaluate the effectiveness of noninvasive acupressure in preventing and diminishing chemotherapy-induced myelosuppression in patients with gynecologic cancer and to determine whether this effect is associated with the regulation of the expressions of granulocyte-macrophage colony-stimulating factor and stem cell factor (SCF). METHODS: In total, 28 women with gynecological cancer were randomly assigned either to the experimental group (n = 10) or to the control group (n = 18). The experimental group received acupressure of 5-minute duration to the Hegu (LI4), Quchi (LI11), Xuehai (SP10), Sanyinjiao (SP6), Taixi (K3), Zusanli (ST36), Taichong (LR3), and Baihui (GV20) points, respectively, three times per day for 6 weeks. The control group did not receive the acupressure intervention. The blood count, including white blood cells, platelets, and hemoglobin, and serum levels for SCF and granulocyte-macrophage colony-stimulating factor were assessed before (pretest) and 6 weeks after (posttest) the participants' first course of chemotherapy. RESULTS: At posttest, blood hemoglobin had significantly decreased from (mean ± SD) 11.6 ± 2.2 to 10.8 ±1.6 mg/dl (p = .03) in the control group. However, no significant pretest-posttest difference in hemoglobin concentration (11.4 ± 1.0 vs. 10.9 ± 1.1 mg/dl) was detected in the experimental group. Levels of SCF increased significantly between pretest and posttest in both the control group (from 1196.10 ± 293.17 to 1325.05 ± 253.77 ng/ml; p = .01) and the acupressure group (from 1046.78 ± 469.52 to 1387.06 ± 310.00 ng/ml; p = .007). In addition, a borderline difference (p = .05) in mean pretest-posttest SCF increase was found between the acupressure group (340.28 ± 255.46 ng/ml) and the control group (128.94 ± 250.64 ng/ml). Finally, a significant time-dependent interactive effect was found between acupressure and the increased blood level of SCF at posttest (ß = 211.34, p = .02). CONCLUSIONS/IMPLICATIONS FOR PRACTICE: The findings support that acupressure on specific acupoints increases blood SCF levels significantly, which may help protect chemotherapy patients from experiencing reduced hemoglobin levels and may relieve chemotherapy-induced myelosuppression in patients with gynecologic cancer. This noninvasive approach is suggested for practical implementation in patients undergoing a course of chemotherapy.
Subject(s)
Acupressure/methods , Antineoplastic Agents/adverse effects , Antineoplastic Agents/therapeutic use , Genital Neoplasms, Female/drug therapy , Leukemia, Myeloid, Acute/etiology , Leukemia, Myeloid, Acute/prevention & control , Stem Cell Factor/blood , Adult , Aged , Aged, 80 and over , Female , Humans , Middle Aged , TaiwanABSTRACT
Lung cancer is one of the major cause of cancer-related deaths worldwide. The poor prognosis and resistance to both radiation and chemotherapy urged the development of potential targets for lung cancer treatment. In this study, using a network-based cellular signature bioinformatics approach, we repurposed a clinically approved mTOR inhibitor for renal cell carcinomans, temsirolimus, as the potential therapeutic candidate for lung adenocarcinoma. The PI3K-AKT-mTOR pathway is known as one of the most frequently dysregulated pathway in cancers, including non-small-cell lung cancer. By using a well-documented lung adenocarcinoma mouse model of human pathophysiology, we examined the effect of temsirolimus on the growth of lung adenocarcinoma in vitro and in vivo. In addition, temsirolimus combined with reduced doses of cisplatin and gemcitabine significantly inhibited the lung tumor growth in the lung adenocarcinoma mouse model compared with the temsirolimus alone or the conventional cisplatin-gemcitabine combination. Functional imaging techniques and microscopic analyses were used to reveal the response mechanisms. Extensive immunohistochemical analyses were used to demonstrate the apparent effects of combined treatments on tumor architecture, vasculature, apoptosis, and the mTOR-pathway. The present findings urge the further exploration of temsirolimus in combination with chemotherapy for treating lung adenocarcinoma.
ABSTRACT
Traditional drug delivery systems, using invasive, transdermal, and oral routes, are limited by various factors, such as the digestive system environment, skin protection, and sensory nerve stimulation. To improve the drug delivery system, we fabricated a polysaccharide-based, dissolvable microneedle-based array, which combines the advantages of both invasive and transdermal delivery systems, and promises to be an innovative solution for minimally invasive drug delivery. In this study, we designed a reusable aluminum mold that greatly improved the efficiency and convenience of microneedle fabrication. Physical characterization of the polysaccharides, individual or mixed at different ratios, was performed to identify a suitable molecule to fabricate the dissolvable microneedle. We used a vacuum deposition-based micro-molding method at low temperature to fabricate the model. Using a series of checkpoints from material into product, a systematic feedback mechanism was built into the "all-in-one" fabrication step, which helped to improve production yields. The physical properties of the fabricated microneedle were assessed. The cytotoxicity analysis and animal testing of the microneedle demonstrated the safety and compatibility of the microneedle, and the successful penetration and effective release of a model protein.
Subject(s)
Biodegradable Plastics , Materials Testing , Needles , Administration, Cutaneous , Animals , Mice , Mice, Inbred BALB C , Mice, Nude , NIH 3T3 CellsABSTRACT
KLF10 is a transforming growth factor (TGF)-ß/Smad downstream regulated gene. KLF10 binds to the promoter of target genes and mimics the effects of TGF-ß as a transcriptional factor. In our laboratory, we noted that Klf10 deficiency in mice is associated with significant inflammation of the lungs. However, the precise mechanism of this association remains unknown. We previously identified NPRA as a target gene potentially regulated by KLF10 through direct binding; NPRA knockout have known that prevented lung inflammation in a mouse model of allergic asthma. Here, we further explored the regulatory association between KLF10 and NPRA on the basis of the aforementioned findings. Our results demonstrated that KLF10 acts as a transcriptional repressor of NPRA and that KLF10 binding reduces NPRA expression in vitro. Compared with wild-type mice, Klf10-deficient mice were more sensitive to lipopolysaccharide or ovalbumin challenge and showed more severe inflammatory histological changes in the lungs. Moreover, Klf10-deficient mice showed pulmonary neutrophil accumulation. These findings collectively reveal the precise site where KLF10 signaling affects pulmonary inflammation by attenuating NPRA expression. They also verify the importance of KLF10 and atrial natriuretic peptide/NPRA in exerting influences on chronic pulmonary disease pathogenesis.
Subject(s)
Early Growth Response Transcription Factors/deficiency , Gene Expression Regulation , Kruppel-Like Transcription Factors/deficiency , Pneumonia/genetics , Pneumonia/metabolism , Receptors, Atrial Natriuretic Factor/genetics , Receptors, Atrial Natriuretic Factor/metabolism , Animals , Capillary Permeability , Humans , Mice , Mice, Inbred C57BL , Neutrophils/cytology , Pneumonia/immunology , Promoter Regions, Genetic/genetics , Transcription, GeneticABSTRACT
Gefitinib resistance has been shown to complicate cancer therapy. Lovastatin is a proteasome inhibitor that enhances gefitinib-induced antiproliferation in non-small cell lung cancer. The objective of this study is to investigate the mechanism of lovastatin-induced antiproliferation in gefitinib-resistant human cholangiocarcinoma.Two gefitinib-resistant cholangiocarcinoma cell lines, SSP-25 and HuH-28, were used in this study to determine how to compensate gefitinib resistance. The combined effect of these two drugs was examined using the MTT assay, qPCR, immunoblotting, flow cytometry, and in vivo xenograft. Results indicated that lovastatin enhanced TNF-α-induced cell death in vitro. In addition, the combination of lovastatin with gefitinib enhanced accumulation of TNF-α. Furthermore, the treatment induced a synergistic cytotoxic effect and antiproliferation through apoptosis in SSP-25 cells and cell cycle arrest in HuH-28 cells. Reproductive results were also observed in in vivo xenografts. These observations suggest that the combination of gefitinib and lovastatin might have additive antiproliferative effects against gefitinib-resistant cholangiocarcinoma cells. Based on these observations, we concluded that the combination of gefitinib and lovastatin could be used to overcome gefitinib resistance in cholangiocarcinoma cells.
Subject(s)
Antineoplastic Agents/pharmacology , Bile Duct Neoplasms/drug therapy , Cholangiocarcinoma/drug therapy , Drug Resistance, Neoplasm/drug effects , Hydroxymethylglutaryl-CoA Reductase Inhibitors/pharmacology , Lovastatin/pharmacology , Quinazolines/pharmacology , AMP-Activated Protein Kinase Kinases , Animals , Apoptosis/drug effects , Bile Duct Neoplasms/pathology , Bile Ducts, Intrahepatic/pathology , Carcinoma, Non-Small-Cell Lung/drug therapy , Cell Cycle Checkpoints/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival , Cholangiocarcinoma/pathology , Drug Synergism , Gefitinib , Humans , Lung Neoplasms/drug therapy , Male , Mice , Mice, Inbred ICR , Protein Serine-Threonine Kinases/metabolism , RNA Interference , RNA, Small Interfering/genetics , Signal Transduction/drug effects , Tumor Necrosis Factor-alpha/metabolism , Xenograft Model Antitumor AssaysABSTRACT
Downregulation of multiple cell cycle-regulatory molecules is a dominant event in TGF-ß1-mediated growth inhibition of human carcinoma cells. It is known that KLF10 mimics the anti-proliferative and apoptotic effects that TGF-ß1 has on epithelial cell growth and the growth of various tumor cells; based on these findings it is considered as a tumor suppressor. KLF10 protein expression is tightly associated with cell cycle-dependent events. However, the regulatory mechanism and its biological meaning have not been identified. In this study, we have demonstrated that KLF10 is a substrate of CDK2/cyclin E and can be phosphorylated. We also have shown that KLF10 efficiently binds to CDK2, while binding much less to CDK4, and displaying no binding to Cdk6. Using mass spectrometry, site direct mutagenesis, in vitro kinase assays and depletion assays, we have established that CDK2 phosphorylates Ser206, which subsequently affects the steady state level of KLF10 in cells. Our studies have also proved that CDK2 up-regulates the protein level of KLF10 through reducing its association with SIAH1, a KLF10 E3-ubiqutin ligase involved in proteasomal degradation. Taken all together, these findings indicate that CDK2-dependent phosphorylation regulates KLF10 stability and that this affects the role of KLF10 in cell.
Subject(s)
Cyclin-Dependent Kinase 2/metabolism , Early Growth Response Transcription Factors/metabolism , Kruppel-Like Transcription Factors/metabolism , Nuclear Proteins/metabolism , Ubiquitin-Protein Ligases/metabolism , Amino Acid Sequence , Cell Line, Tumor , Early Growth Response Transcription Factors/chemistry , Humans , Kruppel-Like Transcription Factors/chemistry , Molecular Sequence Data , Phosphorylation , Phosphoserine/metabolism , Protein Binding , Protein StabilityABSTRACT
TGF-ß plays a significant role in regulating pancreas islet function and maintaining their mass. KLF10, a TGF-ß downstream gene, belongs to a group of Krüppel-like transcription factors that bind to the promoters of target genes and produce effects that mimic TGF-ß as a tumor suppressor. Using ChIP-chip screening, SEI-1 was identified as a target gene that may be regulated by KLF10. We conducted a series of assays to verify the presence of unknown regulation events between SEI-1 and KLF10. These showed that KLF10 transcriptionally activates the SEI-1 promoter and, furthermore, induces SEI-1 protein expression in pancreatic carcinoma cells. SEI-1 is one of the key factors involved in cell cycle control through the regulation of other transcription factors such as the p21(Cip1) gene. Interestingly, it has been shown previously that p21(Cip1) is indirectly activated by KLF10. Our results first demonstrated that KLF10 acts as a transcriptional activator on SEI-1, which can then result in increased p21(Cip1) expression. Furthermore, KLF10-deficiency in mice is associated with a decrease in the pancreatic islet mass, which is similar to the effects found in SEI-1 deficient mice. The KLF10-defect was also associated with the nuclear accumulation of the p21(Cip1) in islet cells. Based on our molecular and histological findings, we conclude that KLF10 plays an important role in pancreatic ß-cells and this supports a functional link between KLF10 and various cell cycle regulators, most notably in the context of the pancreas.
Subject(s)
Cyclin-Dependent Kinase Inhibitor p21/metabolism , Early Growth Response Transcription Factors/metabolism , Kruppel-Like Transcription Factors/metabolism , Nuclear Proteins/metabolism , Pancreas/metabolism , Trans-Activators/metabolism , Animals , Blotting, Western , Cell Line, Tumor , Cyclin-Dependent Kinase Inhibitor p21/genetics , Early Growth Response Transcription Factors/genetics , Electrophoretic Mobility Shift Assay , Glucose Tolerance Test , Humans , Immunohistochemistry , Kruppel-Like Transcription Factors/genetics , Mice , Nuclear Proteins/genetics , Reverse Transcriptase Polymerase Chain Reaction , Trans-Activators/genetics , Transcription FactorsABSTRACT
BACKGROUND: Cancer is the result of a multistep process of genomic alterations, including mutations in key regulatory proteins that result in loss of balanced gene expression and subsequent malignant transformation. Throughout the various stages of colorectal carcinoma (CRC), complex genetic alterations occur, of which over-expression of growth factors, such as vascular endothelial growth factor, fibroblast growth factor and platelet-derive growth factor and their corresponding receptor tyrosine kinases, have been shown to correlate with invasiveness, tumor angiogenesis, metastasis, recurrence, and poor prognosis of colorectal cancer. To evaluate the therapeutic effect, we combined Dovitinib, an orally bioavailable, potent inhibitor of class III-V receptor tyrosine kinases with chemotherapeutic drug, oxaliplatin in preclinical models of colon cancer. METHODS: Human colon cancer cells with different RAS-RAF mutation status (HCT-116, HT-29, SW-480, CaCO2 and LS174T) were treated with a combination of Dovitinib and Oxaliplatin at low dosage followed by assays to investigate the effect of the combination on cell proliferation, cell migration, cell apoptosis and signaling pathways involved in molecular mechanism of drug(s). The antitumor effects of either of the drugs were compared to the combination using human colon carcinoma cell line HT-29 xenograft model. Treated vs untreated tumor sections were also compared for proliferation and angiogenesis markers by immunohistochemistry. RESULTS: The combination of dovitinib and oxaliplatin showed higher in vitro cytotoxicity in colon cell lines irrespective of their RAS-RAF status as compared to either of the drugs alone. Simultaneous inhibition of MAP kinase and AKT pathways and induction of apoptosis via activation of caspases 9/caspases 3 contributed to the synergistic effect of this combination therapy. In the xenograft model, the combination showed a significantly higher antitumor activity. Immunohistochemistry of post treatment tumors showed a significant decrease in proliferation and angiogenesis as compared to either of the treatments alone. CONCLUSIONS: This study demonstrates the synergistic antitumor activity of combination of dovitinib and oxaliplatin against colon cancer with different RAS-RAF status. The combination also showed its antitumor efficacy in a multidrug resistant phenotype xenograft model. This provides a basis for further investigation for its potential in clinical setting for colorectal cancer.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Apoptosis/drug effects , Cell Proliferation/drug effects , Colorectal Neoplasms/pathology , Mutation , Animals , Benzimidazoles/administration & dosage , Blotting, Western , Cell Line, Tumor , Cell Survival/drug effects , Colorectal Neoplasms/genetics , Drug Synergism , Female , Humans , Immunohistochemistry , Mice , Mice, Nude , Oncogene Protein p21(ras)/genetics , Organoplatinum Compounds/administration & dosage , Oxaliplatin , Quinolones/administration & dosage , Xenograft Model Antitumor Assays , raf Kinases/geneticsABSTRACT
KLF10 is now classified as a member of the Krüppel-like transcription factor family and acts as a tumor suppressor. Although KLF10 is originally named as TGF-ß-inducible early gene-1 and mimicking the anti-proliferative effect of TGF-ß in various carcinoma cells, the transcriptional upregulatory function of KLF10 has been described for a variety of cytokines and in many diseases. Through in vivo and in vitro phosphorylation assays, we identified that KLF10 is a phosphorylated protein in cells. Using yeast-two hybrid screening and site direct mutagenesis, we also identified PIN1 as a novel KLF10 associated protein. PIN1 is a peptidyl-prolyl isomerase enzyme belonging to the parvulin family, which specifically recognizes phosphorylated Ser/Thr-Pro containing substrates. Through protein-protein interaction assays, we showed that the Pro-directed Ser/Thr-Pro motif at Thr-93 in the KLF10 N-terminal region is essential for the interaction between KLF10 and PIN1. More importantly, PIN1 interacts with KLF10 in a phosphorylation-dependent manner and this interaction promotes KLF10 protein degradation in cells. Therefore, KLF10 shows shorter protein stability compared with mutant KLF10 that lacks PIN1 binding ability after cycloheximide treatments. The reversely correlated expression profile between KLF10 and PIN1 as observed in cell lines was also shown in clinic pancreatic cancer specimen. Using in vitro kinase assays and depletion assays, we were able to show that RAF-1 phosphorylates the Thr-93 of KLF10 and affects the KLF10 expression level in cells. Thus these findings as a whole indicate that RAF-1 phosphorylation and PIN1 isomerization together regulate KLF10 stability and further affect the role of KLF10 in tumor progression.
Subject(s)
Early Growth Response Transcription Factors/metabolism , Kruppel-Like Transcription Factors/metabolism , Peptidylprolyl Isomerase/metabolism , Phosphothreonine/metabolism , Tumor Suppressor Proteins/metabolism , Amino Acid Motifs , Animals , Cell Line, Tumor , Early Growth Response Transcription Factors/chemistry , Humans , Kruppel-Like Transcription Factors/chemistry , Mice , NIMA-Interacting Peptidylprolyl Isomerase , Phosphorylation , Phosphoserine/metabolism , Protein Binding , Protein Interaction Mapping , Protein Stability , Proteolysis , Proto-Oncogene Proteins c-raf/metabolism , Tumor Suppressor Proteins/chemistryABSTRACT
A 16-amino-acid peptide was isolated from the leaves of sweet potato. The peptide caused a rapid alkalinization response in tomato suspension culture media, a characteristic of defense peptides in plants. No post-translational modification was observed on the peptide according to MALDI-MS analysis. We have named the peptide Ipomoea batatas anti-cancer peptide (IbACP). IbACP also was shown with the ability to dose-dependently inhibit Panc-1, a pancreatic cancer line, cell proliferation. The morphological observations of the Panc-1 cells by phase contrast microscopy showed significant changes after treatment with IbACP. Moreover, caspase-3 and PARP [poly(ADP-ribose) polymerase] were activated by IbACP treatment, followed by cell death. An increase in the levels of cleaved caspase-3 and -9 was also detected by an immunoblot assay after treatment with IbACP. In addition, genomic DNA fragmentation and decreased cellular proliferation were induced when IbACP was supplied to the Panc-1 cells, further demonstrating its biological relevance. The combined data indicates that IbACP peptide may have an important role in the regulation of cellular proliferation by inducing and promoting apoptosis through the mitochondrial apoptotic pathway. This report also showed that IbACP peptide contains potent anti-cancer effects and may play an important role in herbal medicine development.
Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Apoptosis/drug effects , Ipomoea batatas/chemistry , Plant Extracts/chemistry , Plant Leaves/chemistry , Plant Proteins/pharmacology , Amino Acid Sequence , Antineoplastic Agents, Phytogenic/chemistry , Antineoplastic Agents, Phytogenic/isolation & purification , Caspases/genetics , Caspases/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , DNA Fragmentation , Gene Expression/drug effects , Humans , Molecular Sequence Data , Plant Proteins/chemistry , Plant Proteins/isolation & purificationABSTRACT
Krüppel-like family is a group of zinc-finger transcription factors which play key regulatory roles in cellular growth, development, differentiation and vascularization. Recent studies have shown that one of the members, KLF10, is specifically involved in the process of angiogenesis by acting as a key transcriptional regulator of TGF-ß1 in pro-angiogenic cells differentiation and function. KLF10(-/-) mice also displayed impaired blood flow recovery after hindlimb ischemia. However, the mechanism of KLF10 induced angiogenesis is still not well understood. From ChIP-chip, which have been adopt to elucidate the novel target genes and signaling cascades of KLF10, COX-1 (also named as PTGS1) is one of the target genes that may be regulated by Klf10 through promoter binding. In order to investigate the function of KLF10/COX-1 axis, promoter activity, EMSA, ChIP-PCR and tube formation assays were serially performed. Our results demonstrated that KLF10 acts as a transcriptional activator on COX-1 promoter where overexpression of KLF10 induces COX-1 protein expression and mRNA expression in endothelial cells. It has been known that COX-1 is the key enzyme in prostaglandin biosynthesis which regulated angiogenesis in endothelial cells. Using tube formation assay, we further demonstrated that KLF10 overexpressed endothelial cells formed better organized three-dimensional tube structure in contrast to the control group did. To specifically investigate the role for KLF10 in angiogenesis, the its deficient mice exhibited decreased light transmission which represents the extend of platelet aggregation slowing down. Taken together, our results indicate an important role for KLF10 in angiogenesis through the activation of COX-1.
Subject(s)
Cyclooxygenase 1/genetics , Early Growth Response Transcription Factors/physiology , Human Umbilical Vein Endothelial Cells/enzymology , Kruppel-Like Transcription Factors/physiology , Neovascularization, Physiologic , Platelet Aggregation , Animals , Cell Line , Cyclooxygenase 1/metabolism , Enzyme Induction , Hindlimb/blood supply , Human Umbilical Vein Endothelial Cells/physiology , Humans , Ischemia/physiopathology , Mice , Mice, Knockout , Promoter Regions, Genetic , Protein Binding , Transcriptional Activation , Up-RegulationABSTRACT
Deregulation of transforming growth factor (TGF)-ß function is a common feature of pancreatic cancer, rendering these cancers unresponsive to TGF-ß-stimulated growth inhibition. Recent findings have supported a primary role for Krüppel-like factor 10 (KLF10) as an important transcription factor involved in mediating TGF-ß1 signaling. The aim of this study was to evaluate the correlation between KLF10 expression and the clinical and pathologic features of pancreatic cancer. Tissue specimens from patients with pancreatic adenocarcinoma were retrospectively collected for immunohistochemical analysis. To demonstrate that Klf10 expression was primarily regulated by methylation status, the Klf10 promoter was examined by methylation-specific PCR using a pancreatic cancer cell line (Panc-1). DNA methyltransferase (DNMT) inhibitor and small-interfering RNA depletion of DNMT genes were used to reverse KLF10 expression in the Panc-1 cells. In parallel, DNMT1 expression was evaluated in the pancreatic cancer tissue specimens. In 95 pancreatic cancer tissue specimens, KLF10 expression was inversely correlated with pancreatic cancer stage (P = 0.01). Multivariable analysis revealed that, in addition to the presence of distant metastasis at diagnosis (P = 0.001 and 0.001, respectively), KLF10 was another independent prognostic factor related to progression-free and overall survival (P = 0.018 and 0.037, respectively). The loss of KLF10 expression in advanced pancreatic cancer is correlated with altered methylation status, which seems to be regulated by DNMT1. Our results suggest that KLF10 is a potential clinical predictor for progression of pancreatic cancer.