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1.
Cancer Sci ; 110(3): 1085-1095, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30582655

ABSTRACT

Ovarian cancer is the most lethal cancer of the female reproductive system. In that regard, several epidemiological studies suggest that long-term exposure to estrogen could increase ovarian cancer risk, although its precise role remains controversial. To decipher a mechanism for this, we previously generated a mathematical model of how estrogen-mediated upregulation of the transcription factor, E2F6, upregulates the ovarian cancer stem/initiating cell marker, c-Kit, by epigenetic silencing the tumor suppressor miR-193a, and a competing endogenous (ceRNA) mechanism. In this study, we tested that previous mathematical model, showing that estrogen treatment of immortalized ovarian surface epithelial cells upregulated both E2F6 and c-KIT, but downregulated miR-193a. Luciferase assays further confirmed that microRNA-193a targets both E2F6 and c-Kit. Interestingly, ChIP-PCR and bisulphite pyrosequencing showed that E2F6 also epigenetically suppresses miR-193a, through recruitment of EZH2, and by a complex ceRNA mechanism in ovarian cancer cell lines. Importantly, cell line and animal experiments both confirmed that E2F6 promotes ovarian cancer stemness, whereas E2F6 or EZH2 depletion derepressed miR-193a, which opposes cancer stemness, by alleviating DNA methylation and repressive chromatin. Finally, 118 ovarian cancer patients with miR-193a promoter hypermethylation had poorer survival than those without hypermethylation. These results suggest that an estrogen-mediated E2F6 ceRNA network epigenetically and competitively inhibits microRNA-193a activity, promoting ovarian cancer stemness and tumorigenesis.


Subject(s)
E2F6 Transcription Factor/genetics , Neoplastic Stem Cells/pathology , Ovarian Neoplasms/genetics , RNA/genetics , Transcription, Genetic/genetics , Animals , Cell Line, Tumor , DNA Methylation/drug effects , DNA Methylation/genetics , Epigenesis, Genetic/drug effects , Epigenesis, Genetic/genetics , Epithelial Cells/drug effects , Epithelial Cells/pathology , Estrogens/adverse effects , Female , Genes, Tumor Suppressor/physiology , Humans , Mice , Mice, Inbred BALB C , Mice, Nude , Mice, SCID , MicroRNAs/genetics , Neoplastic Stem Cells/drug effects , Ovarian Neoplasms/etiology , Transcription, Genetic/drug effects , Up-Regulation/drug effects , Up-Regulation/genetics
2.
J Biol Chem ; 290(2): 1155-69, 2015 Jan 09.
Article in English | MEDLINE | ID: mdl-25418128

ABSTRACT

Cholesterol catabolism by actinobacteria has been extensively studied. In contrast, the uptake and catabolism of cholesterol by Gram-negative species are poorly understood. Here, we investigated microbial cholesterol catabolism at the subcellular level. (13)C metabolomic analysis revealed that anaerobically grown Sterolibacterium denitrificans, a ß-proteobacterium, adopts an oxygenase-independent pathway to degrade cholesterol. S. denitrificans cells did not produce biosurfactants upon growth on cholesterol and exhibited high cell surface hydrophobicity. Moreover, S. denitrificans did not produce extracellular catabolic enzymes to transform cholesterol. Accordingly, S. denitrificans accessed cholesterol by direction adhesion. Cholesterol is imported through the outer membrane via a putative FadL-like transport system, which is induced by neutral sterols. The outer membrane steroid transporter is able to selectively import various C27 sterols into the periplasm. S. denitrificans spheroplasts exhibited a significantly higher efficiency in cholest-4-en-3-one-26-oic acid uptake than in cholesterol uptake. We separated S. denitrificans proteins into four fractions, namely the outer membrane, periplasm, inner membrane, and cytoplasm, and we observed the individual catabolic reactions within them. Our data indicated that, in the periplasm, various periplasmic and peripheral membrane enzymes transform cholesterol into cholest-4-en-3-one-26-oic acid. The C27 acidic steroid is then transported into the cytoplasm, in which side-chain degradation and the subsequent sterane cleavage occur. This study sheds light into microbial cholesterol metabolism under anoxic conditions.


Subject(s)
Cell Hypoxia , Cholesterol/metabolism , Gram-Negative Bacteria/metabolism , Sterols/metabolism , Anaerobiosis , Carbon Radioisotopes/chemistry , Cholestenones/chemistry , Cholestenones/metabolism , Cholesterol/chemistry , Gram-Negative Bacteria/chemistry , Lipolysis , Metabolism/genetics , Oxidation-Reduction , Periplasm/enzymology , Rhodocyclaceae/enzymology , Sterols/chemistry , Substrate Specificity
3.
Hu Li Za Zhi ; 62(4): 54-62, 2015 Aug.
Article in Zh | MEDLINE | ID: mdl-26242436

ABSTRACT

BACKGROUND: The nursing practice environment has been shown to wield significant influence on nursing retention and nursing quality of care. Because a large percentage of Taiwan nurses currently work at regional teaching hospitals, exploring the perception toward the practice environment of nurses working at this type of hospital is important. PURPOSE: This study explored the perception of nurses working at a regional teaching hospital in central Taiwan toward their practice environment. METHODS: A cross-sectional research design with a sample of 474 nurses from a regional hospital in central Taiwan was conducted. Instruments including the demographic data and the Chinese-version Practice Environment Scale-Nursing Work Index (CPES-NWI) were anonymously self-administered. RESULTS: Overall, participants were moderately satisfied with their practice environment, with the greatest dissatisfaction focused on staffing and resource adequacy. Work unit and nursing level, respectively, had significant impacts on perceptions regarding the practice environment. Furthermore, discriminant analysis identified two new compound variables: 1) adequate staffing resources and partnership in the workplace and 2) supportive administrative management environment. Participants who worked in medical and surgical units were significantly more dissatisfied with the adequacy of staffing resources and partnership in the workplace than participants who worked in acute/intensive and special units. Participants at the N2 level were significantly more dissatisfied with the supportive nature of the administrative management environment. CONCLUSIONS/IMPLICATIONS FOR PRACTICE: These findings support that the nursing practice environment of regional hospitals may be improved using several measures, including: modifying the staffing and resource adequacy of nurses, fostering collaborative nurse-physician relationships, and further involving nurses in administrative management and decision-making.


Subject(s)
Nurses , Perception , Adult , Cross-Sectional Studies , Female , Hospitals, Teaching , Humans , Job Satisfaction , Male , Middle Aged , Taiwan
4.
Appl Environ Microbiol ; 80(11): 3442-52, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24657867

ABSTRACT

The biodegradation of steroids is a crucial biochemical process mediated exclusively by bacteria. So far, information concerning the anoxic catabolic pathways of androgens is largely unknown, which has prevented many environmental investigations. In this work, we show that Sterolibacterium denitrificans DSMZ 13999 can anaerobically mineralize testosterone and some C19 androgens. By using a (13)C-metabolomics approach and monitoring the sequential appearance of the intermediates, we demonstrated that S. denitrificans uses the 2,3-seco pathway to degrade testosterone under anoxic conditions. Furthermore, based on the identification of a C17 intermediate, we propose that the A-ring cleavage may be followed by the removal of a C2 side chain at C-5 of 17-hydroxy-1-oxo-2,3-seco-androstan-3-oic acid (the A-ring cleavage product) via retro-aldol reaction. The androgenic activities of the bacterial culture and the identified intermediates were assessed using the lacZ-based yeast androgen assay. The androgenic activity in the testosterone-grown S. denitrificans culture decreased significantly over time, indicating its ability to eliminate androgens. The A-ring cleavage intermediate (≤ 500 µM) did not exhibit androgenic activity, whereas the sterane-containing intermediates did. So far, only two androgen-degrading anaerobes (Sterolibacterium denitrificans DSMZ 13999 [a betaproteobacterium] and Steroidobacter denitrificans DSMZ 18526 [a gammaproteobacterium]) have been isolated and characterized, and both of them use the 2,3-seco pathway to anaerobically degrade androgens. The key intermediate 2,3-seco-androstan-3-oic acid can be used as a signature intermediate for culture-independent environmental investigations of anaerobic degradation of C19 androgens.


Subject(s)
Androgens/metabolism , Metabolic Networks and Pathways , Rhodocyclaceae/metabolism , Anaerobiosis , Biosensing Techniques/methods , Biotransformation , Carbon Isotopes/metabolism , Isotope Labeling , Metabolomics , Time Factors
5.
Article in English | MEDLINE | ID: mdl-38780901

ABSTRACT

Objective: Hard-to-heal diabetic foot ulcers (DFUs) are associated with higher mortality rates and an increased medical burden for patients. ON101, a new topical cream, exhibited better healing efficacy than the control dressing in a Phase III trial. In this post hoc analysis, we further identify whether ON101 can improve the healing of ulcers with hard-to-heal risk factors in this cohort of DFU patients. Approach: To compare the efficacy of ON101 with absorbent dressing among various hard-to-heal wounds in patients with DFU, a post hoc analysis of a randomized Phase III trial that included 276 DFU patients was performed by subgrouping those patients based on ulcer depth, location, size, duration, and patients' glycated hemoglobin (HbA1c) levels and body mass index (BMI). Results: In the full analysis set, the proportion of patients achieving healing was 61.7% in the ON101 group and 37.0% in the comparator (p = 0.0001). In subgroup analysis according to risk factors, ON101 demonstrated superior healing capacity on Wagner grade 2 ulcers (p < 0.0001); plantar ulcers (p = 0.0016), ulcer size ≥5 cm2 (p = 0.0122), ulcer duration ≥3 months (p = 0.0043); for patients with HbA1c ≥9% (p = 0.0285); and patients with BMI ≥25 (p = 0.0005). Innovation: ON101, a novel therapeutic drug, can modulate the functions of macrophages and demonstrate superior healing rates to conventional absorbent dressing in patients with hard-to-heal DFUs. Conclusions: The results of this post hoc study suggest that ON101 is a better therapeutic option than conventional dressing used in treatment for DFU patients with higher HbA1c, BMI, or ulcers with complex conditions such as longer duration, deeper wounds, larger size, and plantar location.

6.
J Clin Ultrasound ; 41(3): 175-7, 2013.
Article in English | MEDLINE | ID: mdl-22323278

ABSTRACT

Encrustation is one of the most common complications that may develop with the use of a nephrostomy catheter. We used the color Doppler twinkling artifact to detect encrustation and obstruction of a nephrostomy catheter in vivo. This was confirmed by in vitro scanning of the catheter after analyzing the radiogram. Color Doppler twinkling artifact may provide useful information on the management of nephrostomy catheters.


Subject(s)
Catheter Obstruction , Nephrostomy, Percutaneous/instrumentation , Ultrasonography, Doppler, Color , Female , Humans , Middle Aged
7.
J Ultrasound Med ; 31(3): 483-7, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22368139

ABSTRACT

A wandering spleen is a rare condition. It is usually diagnosed when abdominal pain develops secondary to splenic torsion. Although splenic hypermobility is the pathognomonic feature of a wandering spleen, it is rarely revealed by imaging in the subclinical stage. We report 3 patients with a subclinical wandering spleen who had incidental sonographic findings of splenomegaly. Gray scale and color Doppler sonography in the right decubitus position can easily show the migratory nature and perfusion status of a wandering spleen in real time.


Subject(s)
Patient Positioning , Wandering Spleen/diagnostic imaging , Adult , Diagnosis, Differential , Female , Humans , Magnetic Resonance Imaging , Male , Ultrasonography , Wandering Spleen/surgery
8.
J Sci Food Agric ; 92(10): 2069-75, 2012 Aug 15.
Article in English | MEDLINE | ID: mdl-22271629

ABSTRACT

BACKGROUND: Jiang-gua (fermented cucumbers) is a popular traditional fermented food in Taiwan. The microflora of lactic acid bacteria (LAB) in jiang-gua have not been investigated in detail. In this study, LAB from jiang-gua were isolated, characterised and identified. RESULTS: A total of 103 LAB were isolated; 70 cultures were isolated from jiang-gua samples and 33 cultures were isolated from its raw substrate, cucumber. These isolates were mainly characterised phenotypically and then divided into seven groups (A-G) by restriction fragment length polymorphism analysis and sequencing of 16S ribosomal DNA. The isolates were identified as Enterococcus casseliflavus, Leuconostoc lactis, Leuconostoc mesenteroides, Lactobacillus pentosus, Lactobacillus plantarum, Lactobacillus paraplantarum, Lactococcus lactis subsp. lactis, Weissella cibaria and Weissella hellenica. The antibacterial activities of the isolates were determined and 11 Lc. lactis subsp. lactis strains showed inhibitory activity against the indicator strain Lactobacillus sakei JCM 1157(T) . CONCLUSION: Heterofermentative W. cibaria and Leu. lactis were the major LAB found in jiang-gua samples without soy sauce. In soy sauce-added samples, homofermentative L. pentosus and L. plantarum were the most abundant LAB. In addition, the results also suggested that HhaI and RsaI restriction enzymes could be applied to distinguish W. hellenica and Weissella paramesenteroides.


Subject(s)
Antibiosis , Cucumis sativus/microbiology , Food Microbiology , Lactobacillales/genetics , Fermentation , Humans , Phenotype , Polymorphism, Restriction Fragment Length , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Taiwan
9.
Pharmaceutics ; 14(10)2022 Sep 27.
Article in English | MEDLINE | ID: mdl-36297499

ABSTRACT

Diabetic foot ulcers (DFUs) are one of the most costly and troublesome complications of diabetes mellitus. The wound chronicity of DFUs remains the main challenge in the current and future treatment of this condition. Persistent inflammation results in chronic wounds characterized by dysregulation of immune cells, such as M1 macrophages, and impairs the polarization of M2 macrophages and the subsequent healing process of DFUs. The interactive regulation of M1 and M2 macrophages during DFU healing is critical and seems manageable. This review details how cytokines and signalling pathways are co-ordinately regulated to control the functions of M1 and M2 macrophages in normal wound repair. DFUs are defective in the M1-to-M2 transition, which halts the whole wound-healing machinery. Many pre-clinical and clinical innovative approaches, including the application of topical insulin, CCL chemokines, micro RNAs, stem cells, stem-cell-derived exosomes, skin substitutes, antioxidants, and the most recent Phase III-approved ON101 topical cream, have been shown to modulate the activity of M1 and M2 macrophages in DFUs. ON101, the newest clinically approved product in this setting, is designed specifically to down-regulate M1 macrophages and further modulate the wound microenvironment to favour M2 emergence and expansion. Finally, the recent evolution of macrophage modulation therapies and techniques will improve the effectiveness of the treatment of diverse DFUs.

10.
JID Innov ; 2(5): 100138, 2022 Sep.
Article in English | MEDLINE | ID: mdl-36017415

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 medium‒mediated 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.

11.
JAMA Netw Open ; 4(9): e2122607, 2021 09 01.
Article in English | MEDLINE | ID: mdl-34477854

ABSTRACT

Importance: Delayed healing of diabetic foot ulcers (DFUs) is known to be caused by dysregulated M1/M2-type macrophages, and restoring the balance between these macrophage types plays a critical role in healing. However, drugs used to regulate M1/M2 macrophages have not yet been studied in large randomized clinical trials. Objective: To compare the topical application of ON101 cream with use of an absorbent dressing (Hydrofiber; ConvaTec Ltd) when treating DFUs. Design, Setting, and Participants: This multicenter, evaluator-blinded, phase 3 randomized clinical trial was performed in 21 clinical and medical centers across the US, China, and Taiwan from November 23, 2012, to May 11, 2020. Eligible patients with debrided DFUs of 1 to 25 cm2 present for at least 4 weeks and with Wagner grade 1 or 2 were randomized 1:1 to receive ON101 or control absorbent dressings. Interventions: Twice-daily applications of ON101 or a absorbent dressing changed once daily or 2 to 3 times a week for 16 weeks, with a 12-week follow-up. Main Outcomes and Measures: The primary outcome was the incidence of complete healing, defined as complete re-epithelialization at 2 consecutive visits during the treatment period assessed on the full-analysis set (FAS) of all participants with postrandomization data collected. Safety outcomes included assessment of the incidences of adverse events, clinical laboratory values, and vital signs. Results: In the FAS, 236 eligible patients (175 men [74.2%]; mean [SD] age, 57.0 [10.9] years; mean [SD] glycated hemoglobin level, 8.1% [1.6%]) with DFUs classified as Wagner grade 1 or 2 (mean [SD] ulcer area, 4.8 [4.4] cm2) were randomized to receive either the ON101 cream (n = 122) or the absorbent dressing (n = 114) for as long as 16 weeks. The incidence of complete healing in the FAS included 74 patients (60.7%) in the ON101 group and 40 (35.1%) in the comparator group during the 16-week treatment period (difference, 25.6 percentage points; odds ratio, 2.84; 95% CI, 1.66-4.84; P < .001). A total of 7 (5.7%) treatment-emergent adverse events occurred in the ON101 group vs 5 (4.4%) in the comparator group. No treatment-related serious adverse events occurred in the ON101 group vs 1 (0.9%) in the comparator group. Conclusions and Relevance: In this multicenter randomized clinical trial, ON101 exhibited better healing efficacy than absorbent dressing alone in the treatment of DFUs and showed consistent efficacy among all patients, including those with DFU-related risk factors (glycated hemoglobin level, ≥9%; ulcer area, >5 cm2; and DFU duration, ≥6 months). Trial Registration: ClinicalTrials.gov Identifier: NCT01898923.


Subject(s)
Dermatologic Agents/therapeutic use , Diabetic Foot/drug therapy , Plant Extracts/therapeutic use , Wound Healing , Adult , Aged , Aged, 80 and over , Bandages , China , Dermatologic Agents/administration & dosage , Disease-Free Survival , Female , Humans , Macrophages , Male , Middle Aged , Plant Extracts/administration & dosage , Single-Blind Method , Taiwan , Treatment Outcome , United States , Young Adult
12.
Hepatology ; 49(5): 1571-82, 2009 May.
Article in English | MEDLINE | ID: mdl-19296470

ABSTRACT

UNLABELLED: MicroRNAs (miRNAs), which are inhibitors of gene expression, participate in diverse biological functions and in carcinogenesis. In this study, we show that liver-specific microRNA-122 (miR-122) is significantly down-regulated in liver cancers with intrahepatic metastasis and negatively regulates tumorigenesis. Restoration of miR-122 in metastatic Mahlavu and SK-HEP-1 cells significantly reduced in vitro migration, invasion, and anchorage-independent growth as well as in vivo tumorigenesis, angiogenesis, and intrahepatic metastasis in an orthotopic liver cancer model. Because an inverse expression pattern is often present between an miRNA and its target genes, we used a computational approach and identified multiple miR-122 candidate target genes from two independent expression microarray datasets. Thirty-two target genes were empirically verified, and this group of genes was enriched with genes regulating cell movement, cell morphology, cell-cell signaling, and transcription. We further showed that one of the miR-122 targets, ADAM17 (a disintegrin and metalloprotease 17) is involved in metastasis. Silencing of ADAM17 resulted in a dramatic reduction of in vitro migration, invasion, in vivo tumorigenesis, angiogenesis, and local invasion in the livers of nude mice, which is similar to that which occurs with the restoration of miR-122. CONCLUSION: Our study suggests that miR-122, a tumor suppressor microRNA affecting hepatocellular carcinoma intrahepatic metastasis by angiogenesis suppression, exerts some of its action via regulation of ADAM17. Restoration of miR-122 has a far-reaching effect on the cell. Using the concomitant down-regulation of its targets, including ADAM17, a rational therapeutic strategy based on miR-122 may prove to be beneficial for patients with hepatocellular carcinoma.


Subject(s)
ADAM Proteins/metabolism , Carcinoma, Hepatocellular/metabolism , Liver Neoplasms/metabolism , MicroRNAs/metabolism , 3' Untranslated Regions , ADAM17 Protein , Animals , Antagomirs , Carcinoma, Hepatocellular/pathology , Cell Adhesion , Cell Line, Tumor , Cell Movement , Down-Regulation , Gene Expression Regulation, Neoplastic , Gene Knockdown Techniques , Humans , Liver/pathology , Liver Neoplasms/pathology , Mice , Mice, Nude , Neoplasm Invasiveness , Neoplasm Metastasis , Oligonucleotide Array Sequence Analysis , Oligonucleotides
13.
J Immunother Cancer ; 8(2)2020 11.
Article in English | MEDLINE | ID: mdl-33243934

ABSTRACT

BACKGROUND: The immune checkpoint blockade (ICB) targeting programmed cell death-1 (PD-1) and its ligand (PD-L1) has been proved beneficial for numerous types of cancers, including non-small-cell lung cancer (NSCLC). However, a significant number of patients with NSCLC still fail to respond to ICB due to unfavorable tumor microenvironment. To improve the efficacy, the immune-chemotherapy combination with pemetrexed, cis/carboplatin and pembrolizumab (anti-PD-1) has been recently approved as first-line treatment in advanced NSCLCs. While chemotherapeutic agents exert beneficial effects, the underlying antitumor mechanism(s) remains unclear. METHODS: Pemetrexed, cisplatin and other chemotherapeutic agents were tested for the potential to induce PD-L1 expression in NSCLC cells by immunoblotting and flow cytometry. The ability to prime the tumor immune microenvironment was then determined by NSCLC/T cell coculture systems and syngeneic mouse models. Subpopulations of NSCLC cells responding differently to pemetrexed were selected and subjected to RNA-sequencing analysis. The key signaling pathways were identified and validated in vitro and in vivo. RESULTS: Pemetrexed induced the transcriptional activation of PD-L1 (encoded by CD274) by inactivating thymidylate synthase (TS) in NSCLC cells and, in turn, activating T-lymphocytes when combined with the anti-PD-1/PD-L1 therapy. Nuclear factor κB (NF-κB) signaling was activated by intracellular reactive oxygen species (ROSs) that were elevated by pemetrexed-mediated TS inactivation. The TS-ROS-NF-κB regulatory axis actively involves in pemetrexed-induced PD-L1 upregulation, whereas when pemetrexed fails to induce PD-L1 expression in NSCLC cells, NF-κB signaling is unregulated. In syngeneic mouse models, the combinatory treatment of pemetrexed with anti-PD-L1 antibody created a more favorable tumor microenvironment for the inhibition of tumor growth. CONCLUSIONS: Our findings reveal novel mechanisms showing that pemetrexed upregulates PD-L1 expression and primes a favorable microenvironment for ICB, which provides a mechanistic basis for the combinatory chemoimmunotherapy in NSCLC treatment.


Subject(s)
Antineoplastic Agents/therapeutic use , Immune Checkpoint Inhibitors/therapeutic use , Pemetrexed/therapeutic use , Animals , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Humans , Immune Checkpoint Inhibitors/pharmacology , Mice , Mice, Nude , Pemetrexed/pharmacology , Signal Transduction , Tumor Microenvironment
14.
Nucleic Acids Res ; 31(22): 6481-92, 2003 Nov 15.
Article in English | MEDLINE | ID: mdl-14602906

ABSTRACT

The N terminal region of hepatitis delta antigen (HDAg), referred to here as NdAg, has a nucleic acid chaperone activity that modulates the ribozyme activity of hepatitis delta virus (HDV) RNA and stimulates hammerhead ribozyme catalysis. We characterized the nucleic acid binding properties of NdAg, identified the structural and sequence domains important for nucleic acid binding, and studied the correlation between the nucleic acid binding ability and the nucleic acid chaperone activity. NdAg does not recognize the catalytic core of HDV ribozyme specifically. Instead, NdAg interacts with a variety of nucleic acids and has higher affinities to longer nucleic acids. The studies with RNA homopolymers reveal that the binding site size of NdAg is around nine nucleotides long. The extreme N terminal portion of NdAg, the following coiled-coil domain and the basic amino acid clusters in these regions are important for nucleic acid binding. The nucleic acid-NdAg complex is stabilized largely by electrostatic interactions. The formation of RNA-protein complex appears to be a prerequisite for facilitating hammerhead ribozyme catalysis of NdAg and its derivatives. Mutations that reduce the RNA binding activity or high ionic strength that destabilizes the RNA-protein complex, reduce the nucleic acid chaperone activity of NdAg.


Subject(s)
Hepatitis Delta Virus/metabolism , Hepatitis delta Antigens/metabolism , RNA, Viral/metabolism , RNA-Binding Proteins/metabolism , Amino Acid Sequence , Base Sequence , Binding Sites/genetics , Binding, Competitive , Circular Dichroism , Hepatitis Delta Virus/genetics , Hepatitis delta Antigens/chemistry , Hepatitis delta Antigens/genetics , Macromolecular Substances , Molecular Sequence Data , Mutation , Protein Binding , RNA, Catalytic/metabolism , RNA, Viral/chemistry , RNA-Binding Proteins/chemistry , RNA-Binding Proteins/genetics , Sequence Homology, Amino Acid
15.
Stem Cells Int ; 2016: 2732705, 2016.
Article in English | MEDLINE | ID: mdl-26989421

ABSTRACT

Epithelial-derived tumor cells acquire the capacity for epithelial-to-mesenchymal transition (EMT), which enables them to invade adjacent tissues and/or metastasize to distant organs. Cancer metastasis is the main cause of cancer-related death. Molecular mechanisms involved in the switch from an epithelial phenotype to mesenchymal status are complicated and are controlled by a variety of signaling pathways. Recently, a set of noncoding RNAs (ncRNAs), including miRNAs and long noncoding RNAs (lncRNAs), were found to modulate gene expressions at either transcriptional or posttranscriptional levels. These ncRNAs are involved in EMT through their interplay with EMT-related transcription factors (EMT-TFs) and EMT-associated signaling. Reciprocal regulatory interactions between lncRNAs and miRNAs further increase the complexity of the regulation of gene expression and protein translation. In this review, we discuss recent findings regarding EMT-regulating ncRNAs and their associated signaling pathways involved in cancer progression.

16.
Nat Commun ; 7: 13867, 2016 12 22.
Article in English | MEDLINE | ID: mdl-28004751

ABSTRACT

Hypoxia is a major driving force of cancer invasion and metastasis. Here we show that death domain-associated protein (Daxx) acts to negatively regulate hypoxia-induced cell dissemination and invasion by inhibiting the HIF-1α/HDAC1/Slug pathway. Daxx directly binds to the DNA-binding domain of Slug, impeding histone deacetylase 1 (HDAC1) recruitment and antagonizing Slug E-box binding. This, in turn, stimulates E-cadherin and occludin expression and suppresses Slug-mediated epithelial-mesenchymal transition (EMT) and cell invasiveness. Under hypoxic conditions, stabilized hypoxia-inducible factor (HIF)-1α downregulates Daxx expression and promotes cancer invasion, whereas re-expression of Daxx represses hypoxia-induced cancer invasion. Daxx also suppresses Slug-mediated lung cancer metastasis in an orthotopic lung metastasis mouse model. Using clinical tumour samples, we confirmed that the HIF-1α/Daxx/Slug pathway is an outcome predictor. Our results support that Daxx can act as a repressor in controlling HIF-1α/HDAC1/Slug-mediated cancer cell invasion and is a potential therapeutic target for inhibition of cancer metastasis.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Histone Deacetylase 1/metabolism , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Lung Neoplasms/metabolism , Lung Neoplasms/secondary , Nuclear Proteins/metabolism , Snail Family Transcription Factors/metabolism , Adaptor Proteins, Signal Transducing/chemistry , Adaptor Proteins, Signal Transducing/genetics , Animals , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/secondary , Cell Line, Tumor , Co-Repressor Proteins , Epithelial-Mesenchymal Transition , Histone Deacetylase 1/chemistry , Histone Deacetylase 1/genetics , Humans , Hypoxia-Inducible Factor 1, alpha Subunit/chemistry , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Lung Neoplasms/genetics , Male , Mice , Mice, Inbred BALB C , Mice, Inbred NOD , Mice, Nude , Mice, SCID , Models, Biological , Molecular Chaperones , Neoplasm Invasiveness/prevention & control , Nuclear Proteins/chemistry , Nuclear Proteins/genetics , Protein Binding , Protein Interaction Domains and Motifs , Signal Transduction , Snail Family Transcription Factors/chemistry , Snail Family Transcription Factors/genetics , Transcriptome , Tumor Hypoxia/physiology , Tumor Suppressor Proteins/chemistry , Tumor Suppressor Proteins/genetics , Tumor Suppressor Proteins/metabolism
17.
Oncotarget ; 7(1): 386-401, 2016 Jan 05.
Article in English | MEDLINE | ID: mdl-26561205

ABSTRACT

Melanoma differentiation-associated gene-9 (MDA-9)/Syntenin is a novel therapeutic target because it plays critical roles in cancer progression and exosome biogenesis. Here we show that Slug, a key epithelial-mesenchymal-transition (EMT) regulator, is a MDA-9/Syntenin downstream target. Mitogen EGF stimulation increases Slug expression and MDA-9/Syntenin nuclear translocation. MDA-9/Syntenin uses its PDZ1 domain to bind with Slug, and this interaction further leads to HDAC1 recruitment, up-regulation of Slug transcriptional repressor activity, enhanced Slug-mediated EMT, and promotion of cancer invasion and metastasis. The PDZ domains and nuclear localization of MDA-9/Syntenin are both required for promoting Slug-mediated cancer invasion. Clinically, patients with high MDA-9/Syntenin and high Slug expressions were associated with poor overall survival compared to those with low expression in lung adenocarcinomas. Our findings provide evidence that MDA-9/Syntenin acts as a pivotal adaptor of Slug and it transcriptionally enhances Slug-mediated EMT to promote cancer invasion and metastasis.


Subject(s)
Adenocarcinoma/genetics , Epithelial-Mesenchymal Transition/genetics , Lung Neoplasms/genetics , Syntenins/genetics , Transcription Factors/genetics , Adenocarcinoma/metabolism , Adenocarcinoma/pathology , Animals , Cell Line, Tumor , Female , Gene Expression Regulation, Neoplastic , HEK293 Cells , Humans , Immunoblotting , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , MCF-7 Cells , Male , Mice, Inbred NOD , Mice, SCID , Microscopy, Confocal , Neoplasm Invasiveness , Neoplasm Metastasis , Protein Binding , RNA Interference , Reverse Transcriptase Polymerase Chain Reaction , Snail Family Transcription Factors , Survival Analysis , Syntenins/metabolism , Transcription Factors/metabolism , Transplantation, Heterologous
18.
J Fam Psychol ; 29(6): 895-906, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26168265

ABSTRACT

This article examines the relationship between parenting styles and the development of depressive symptoms among adolescents. We analyzed a nationally representative longitudinal data set of adolescents aged 12 to 14 in Taiwan. Results from growth mixture modeling revealed a nonlinear increase in the intensity of depressive symptoms between early and middle adolescence. More pronounced depressive symptoms in earlier years were also shown to be associated with more rapid development of similar symptoms later in adolescence. Perceived parenting styles, as manifest in parental warmth and harsh discipline, were categorized into 4 latent heterogeneous classes: attentive, reserved, austere, and conflicting. Adolescents living under austere parenting tend to report the most pronounced depressive symptoms from early to middle adolescence; however, the development of symptoms in this group was the slowest. We also discuss the role of harsh parenting in Chinese culture, as it pertains to the roles traditionally assumed by the father and mother.


Subject(s)
Adolescent Behavior/psychology , Depressive Disorder/psychology , Parent-Child Relations , Parenting/psychology , Adolescent , Female , Humans , Longitudinal Studies , Male , Taiwan
19.
Oncotarget ; 6(35): 37349-66, 2015 Nov 10.
Article in English | MEDLINE | ID: mdl-26497368

ABSTRACT

Dysfunction of the mitochondria is well-known for being associated with cancer progression. In the present study, we analyzed the mitochondria proteomics of lung cancer cell lines with different invasion abilities and found that EGFR is highly expressed in the mitochondria of highly invasive non-small-cell lung cancer (NSCLC) cells. EGF induces the mitochondrial translocation of EGFR; further, it leads to mitochondrial fission and redistribution in the lamellipodia, upregulates cellular ATP production, and enhances motility in vitro and in vivo. Moreover, EGFR can regulate mitochondrial dynamics by interacting with Mfn1 and disturbing Mfn1 polymerization. Overexpression of Mfn1 reverses the phenotypes resulting from EGFR mitochondrial translocation. We show that the mitochondrial EGFR expressions are higher in paired samples of the metastatic lymph node as compared with primary lung tumor and are inversely correlated with the overall survival in NSCLC patients. Therefore, our results demonstrate that besides the canonical role of EGFR as a receptor tyrosine, the mitochondrial translocation of EGFR may enhance cancer invasion and metastasis through regulating mitochondria dynamics.


Subject(s)
Carcinoma, Non-Small-Cell Lung/enzymology , Cell Movement , ErbB Receptors/metabolism , Lung Neoplasms/enzymology , Mitochondria/enzymology , Mitochondrial Dynamics , Animals , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/secondary , Cell Line, Tumor , Cell Movement/drug effects , Dose-Response Relationship, Drug , Endocytosis , Energy Metabolism , Epidermal Growth Factor/pharmacology , ErbB Receptors/agonists , ErbB Receptors/genetics , GTP Phosphohydrolases/genetics , GTP Phosphohydrolases/metabolism , Genotype , Heterografts , Humans , Lung Neoplasms/genetics , Lung Neoplasms/pathology , Lymphatic Metastasis , Male , Mice, Inbred NOD , Mice, SCID , Mitochondria/drug effects , Mitochondria/pathology , Mitochondrial Dynamics/drug effects , Mitochondrial Membrane Transport Proteins/genetics , Mitochondrial Membrane Transport Proteins/metabolism , Phenotype , Protein Transport , Proteomics/methods , Signal Transduction , Time Factors , Transfection
20.
Curr Pharm Des ; 20(33): 5309-18, 2014.
Article in English | MEDLINE | ID: mdl-24479807

ABSTRACT

The epithelial-mesenchymal transition (EMT) is a process by which epithelial tumor cells acquire migratory and invasive abilities that enable them to spread to other organs. During this process, the tight junction molecule, E-cadherin, is often downregulated through transcription repression by the EMT-inducing transcription factors (EMT-TFs). MicroRNAs (miRNAs) are a class of small noncoding RNA molecules which bind to the complementary sequences within mRNA molecules. They post-transcriptionally govern gene silencing, thus affecting a broad range of physiological conditions, including EMT. In this review, we will discuss some well-known as well as brand-new EMT-related miRNAs and the signaling pathways in the tumor milieu that regulate their expressions and control cancer invasion and metastasis. Finally, we will discuss the application of miRNAs as therapeutic targets for treatment of cancer.


Subject(s)
Epithelial-Mesenchymal Transition , MicroRNAs/metabolism , Neoplasms/metabolism , Animals , Humans , Neoplasms/genetics , Neoplasms/therapy
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