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1.
AIDS Res Ther ; 21(1): 59, 2024 Aug 29.
Article in English | MEDLINE | ID: mdl-39210349

ABSTRACT

INTRODUCTION: People living with HIV (PLHIV) have a 20-fold risk of tuberculosis (TB) disease compared to HIV-negative people. In 2021, the uptake of TB preventive treatment among the children and adolescents living with HIV at the Baylor-Uganda HIV clinic was 45%, which was below the national target of 90%. Minimal evidence documents the enablers and barriers to TB preventive treatment (TPT) initiation and completion among children and adolescents living with HIV(CALHIV). We explored the facilitators and barriers to TPT initiation and completion among CALHIV among adolescents aged 10-19years and caretakers of children below 18years. METHODS: We conducted a qualitative study from February 2022 to March 2023, at three paediatric and adolescent HIV treatment centers in Uganda. In-depth interviews were conducted at TPT initiation and after completion for purposively selected health workers, adolescents aged 10-19 years living with HIV, and caretakers of children aged below 18years. RESULTS: The desire to avoid TB disease, previous TB treatment, encouragement from family members, and ministry of health policies emerged as key facilitators for the children and adolescents to initiate TPT. Barriers to TPT initiation included; TB and HIV-related stigma, busy carer and adolescent work schedules, reduced social support from parents and family, history of drug side effects, high pill burden and fatigue, and perception of not being ill. TPT completion was enabled by combined TPT and ART refill visits, delivery of ART and TPT within the community, and continuous education and counseling from health workers. Reported barriers to TPT completion included TB and HIV-related stigma, long waiting time. Non-disclosure of HIV status by caretakers to CALHIV and fear of side effects was cited by health workers as a barrier to starting TPT. Facilitators of TPT initiation and completion reported by healthcare workers included patient and caretaker health education, counselling about benefits of TPT and risk of TB disease, having same appointment for TPT and ART refill to reduce patient waiting time, adolescent-friendly services, and appointment reminder phone calls. CONCLUSION: The facilitators and barriers of TPT initiation and completion among CALHIV span from individual, to health system and structural factors. Health education about benefits of TPT and risk of TB, social support, adolescent-friendly services, and joint appointments for TPT and ART refill are major facilitators of TPT initiation and completion among CALHIV in Uganda.


Subject(s)
Caregivers , HIV Infections , Health Personnel , Qualitative Research , Tuberculosis , Humans , Adolescent , Uganda , HIV Infections/drug therapy , HIV Infections/prevention & control , Female , Male , Child , Tuberculosis/prevention & control , Young Adult , Caregivers/psychology , Antitubercular Agents/therapeutic use , Patient Acceptance of Health Care , Adult , Social Stigma , Health Knowledge, Attitudes, Practice , Health Services Accessibility
2.
Childs Nerv Syst ; 40(9): 2883-2891, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38806857

ABSTRACT

PURPOSE: Pediatric hydrocephalus is the most common cause of surgically treatable neurological disease in children. Controversies exist whether endoscopic third ventriculostomy (ETV) or cerebrospinal fluid (CSF) shunt placement is the most appropriate treatment for pediatric hydrocephalus. This study aimed to compare the risk of re-operation and death between the two procedures. METHODS: We performed a retrospective population-based cohort study and included patients younger than 20-years-old who underwent CSF shunt or ETV for hydrocephalus from the Taiwan National Health Insurance Research Database. RESULTS: A total of 3,555 pediatric patients from 2004 to 2017 were selected, including 2,340 (65.8%) patients that received CSF shunt placement and 1215 (34.2%) patients that underwent ETV. The incidence of all-cause death was 3.31 per 100 person-year for CSF shunt group and 2.52 per 100 person-year for ETV group, with an adjusted hazard ratio (HR) of 0.79 (95% confidence interval [CI] = 0.66-0.94, p = 0.009). The cumulative incidence competing risk for reoperation was 31.2% for the CSF shunt group and 26.4% for the ETV group, with an adjusted subdistribution HR of 0.82 (95% CI = 0.70-0.96, p = 0.015). Subgroup analysis showed that ETV was beneficial for hydrocephalus coexisting with brain or spinal tumor, central nervous system infection, and intracranial hemorrhage. CONCLUSION: Our data indicates ETV is a better operative procedure for pediatric hydrocephalus when advanced surgical techniques and instruments are available.


Subject(s)
Cerebrospinal Fluid Shunts , Hydrocephalus , Neuroendoscopy , Third Ventricle , Ventriculostomy , Humans , Hydrocephalus/surgery , Ventriculostomy/methods , Male , Female , Taiwan/epidemiology , Child, Preschool , Child , Infant , Retrospective Studies , Third Ventricle/surgery , Adolescent , Cerebrospinal Fluid Shunts/methods , Neuroendoscopy/methods , Reoperation/statistics & numerical data , Cohort Studies , Infant, Newborn , Treatment Outcome , Young Adult
3.
Nat Commun ; 13(1): 7448, 2022 12 02.
Article in English | MEDLINE | ID: mdl-36460642

ABSTRACT

Immunoglobulin family and carbohydrate vascular addressins encoded by Madcam1 and St6gal1 control lymphocyte homing into intestinal tissues, regulating immunity and inflammation. The addressins are developmentally programmed to decorate endothelial cells lining gut post-capillary and high endothelial venules (HEV), providing a prototypical example of organ- and segment-specific endothelial specialization. We identify conserved NKX-COUP-TFII composite elements (NCCE) in regulatory regions of Madcam1 and St6gal1 that bind intestinal homeodomain protein NKX2-3 cooperatively with venous nuclear receptor COUP-TFII to activate transcription. The Madcam1 element also integrates repressive signals from arterial/capillary Notch effectors. Pan-endothelial COUP-TFII overexpression induces ectopic addressin expression in NKX2-3+ capillaries, while NKX2-3 deficiency abrogates expression by HEV. Phylogenetically conserved NCCE are enriched in genes involved in neuron migration and morphogenesis of the heart, kidney, pancreas and other organs. Our results define an NKX-COUP-TFII morphogenetic code that targets expression of mucosal vascular addressins.


Subject(s)
Endothelial Cells , Veins , Morphogenesis/genetics , Arteries , Cell Movement
4.
Sci Rep ; 12(1): 10825, 2022 06 26.
Article in English | MEDLINE | ID: mdl-35754051

ABSTRACT

Racial disparities in mortality due to metastasis remain significant among breast cancer patients. Chemokine receptors contribute to breast tumors and metastatic outcome. We explored for significant differences in chemokine receptor expression in breast tumors from Black, Asian, and White patients in The Cancer Genome Atlas. We show that despite sharing the same molecular subtype, expression of the chemokine receptors ACKR1, CCR3, CCR6, CCRL1, CCRL2, CXCR1, CXCR2, CXCR4, CXCR6, and CXC3CR1 was significantly different depending on racial group. For patients with triple negative breast cancer, CCR3 was higher in Black versus White and CCRL2 was higher in Asian versus White. In luminal A tumors, ACKR1 was lower in Asian versus White, CCR3 was higher in Black versus White, and CCR6 and CXC3CR1 were lower in Black versus White. In luminal B tumors, CCRL2 was lower in Black versus White, CXCR1 and CXC3CR1 were lower in Asian versus White, and CXCR2 was lower in Black and Asian versus White. In HER2 enriched tumors, CCR3 was higher in Black versus White and CXCR4 lower in Asian versus White. CCR3, CCR6, and CXCR6 associated with worse patient survival. These findings can inform improved treatment strategies to decrease racial disparities in breast cancer burden.


Subject(s)
Breast Neoplasms , Receptors, Chemokine , Triple Negative Breast Neoplasms , Breast/pathology , Breast Neoplasms/ethnology , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cohort Studies , Female , Humans , Racial Groups , Receptors, Chemokine/biosynthesis , Receptors, Chemokine/genetics , Triple Negative Breast Neoplasms/ethnology , Triple Negative Breast Neoplasms/genetics , Triple Negative Breast Neoplasms/metabolism
5.
Genes (Basel) ; 13(2)2022 02 21.
Article in English | MEDLINE | ID: mdl-35205431

ABSTRACT

In human cells, the U12 spliceosome, also known as the minor spliceosome, is responsible for the splicing of 0.5% of introns, while the major U2 spliceosome is responsible for the other 99.5%. While many studies have been done to characterize and understand splicing dysregulation in cancer, almost all of them have focused on U2 splicing and ignored U12 splicing, despite evidence suggesting minor splicing is involved in cell cycle regulation. In this study, we analyzed RNA-seq data from The Cancer Genome Atlas for 14 different cohorts to determine differential splicing of minor introns in tumor and adjacent normal tissue. We found that in some cohorts, such as breast cancer, there was a strong skew towards minor introns showing increased splicing in the tumor; in others, such as the renal chromophobe cell carcinoma cohort, the opposite pattern was found, with minor introns being much more likely to have decreased splicing in the tumor. Further analysis of gene expression did not reveal any candidate regulatory mechanisms that could cause these different minor splicing phenotypes between cohorts. Our data suggest context-dependent roles of the minor spliceosome in tumorigenesis and provides a foundation for further investigation of minor splicing in cancer, which could then serve as a basis for novel therapeutic strategies.


Subject(s)
Neoplasms , RNA Splicing , Humans , Introns/genetics , Neoplasms/genetics , Neoplasms/metabolism , RNA Splicing/genetics , Spliceosomes/genetics , Spliceosomes/metabolism
6.
Sci Rep ; 11(1): 21899, 2021 11 09.
Article in English | MEDLINE | ID: mdl-34753991

ABSTRACT

Pre- and post-transcriptional modifications of gene expression are emerging as foci of disease studies, with some studies revealing the importance of non-coding transcripts, like long non-coding RNAs (lncRNAs) and microRNAs (miRNAs). We hypothesize that transcription factors (TFs), lncRNAs and miRNAs modulate immune response in bovine mastitis and could potentially serve as disease biomarkers and/or drug targets. With computational analyses, we identified candidate genes potentially regulated by miRNAs and lncRNAs base pair complementation and thermodynamic stability of binding regions. Remarkably, we found six miRNAs, two being bta-miR-223 and bta-miR-24-3p, to bind to several targets. LncRNAs NONBTAT027932.1 and XR_003029725.1, were identified to target several genes. Functional and pathway analyses revealed lipopolysaccharide-mediated signaling pathway, regulation of chemokine (C-X-C motif) ligand 2 production and regulation of IL-23 production among others. The overarching interactome deserves further in vitro/in vivo explication for specific molecular regulatory mechanisms during bovine mastitis immune response and could lay the foundation for development of disease markers and therapeutic intervention.


Subject(s)
Gene Regulatory Networks , Mastitis, Bovine/genetics , MicroRNAs/genetics , RNA, Long Noncoding/genetics , Transcription Factors/genetics , Animals , Cattle , Gene Ontology , Mastitis, Bovine/immunology , Thermodynamics
7.
Life (Basel) ; 11(8)2021 Jul 26.
Article in English | MEDLINE | ID: mdl-34440489

ABSTRACT

CXCR3 is a chemokine receptor with two well-characterized isoforms that have unique, context-dependent roles: CXCR3-A and CXCR3-B, which are produced through alternative 3' splice site selection (A3SS). RNA-seq data from The Cancer Genome Atlas (TCGA) were used to correlate CXCR3 expression with breast cancer progression. This analysis revealed significant CXCR3 expression patterns associated with survival and differential expression between the tumor and adjacent normal tissue. TCGA data were used to estimate abundance of immune cells in breast cancer, which demonstrated the association of CXCR3 with immune infiltration, particularly in the triple-negative subtype. Given the importance of A3SS in CXCR3, genome-wide analysis of A3SS events was performed to identify events that were differentially spliced between breast cancer tissue and adjacent normal tissue. A total of 481 splicing events in 424 genes were found to be differentially spliced. The parent genes of differentially spliced events were enriched in RNA processing and splicing functions, indicating an underappreciated role of A3SS in the integrated splicing network of breast cancer. These results further validated the role of CXCR3 in immune infiltration of tumors, while raising questions about the role of A3SS splicing.

8.
Front Immunol ; 12: 644664, 2021.
Article in English | MEDLINE | ID: mdl-34135889

ABSTRACT

Alphaherpesviruses (α-HV) are a large family of double-stranded DNA viruses which cause many human and animal diseases. There are three human α-HVs: Herpes Simplex Viruses (HSV-1 and HSV-2) and Varicella Zoster Virus (VZV). All α-HV have evolved multiple strategies to suppress or exploit host cell innate immune signaling pathways to aid in their infections. All α-HVs initially infect epithelial cells (primary site of infection), and later spread to infect innervating sensory neurons. As with all herpesviruses, α-HVs have both a lytic (productive) and latent (dormant) stage of infection. During the lytic stage, the virus rapidly replicates in epithelial cells before it is cleared by the immune system. In contrast, latent infection in host neurons is a life-long infection. Upon infection of mucosal epithelial cells, herpesviruses immediately employ a variety of cellular mechanisms to evade host detection during active replication. Next, infectious viral progeny bud from infected cells and fuse to neuronal axonal terminals. Here, the nucleocapsid is transported via sensory neuron axons to the ganglion cell body, where latency is established until viral reactivation. This review will primarily focus on how HSV-1 induces various innate immune responses, including host cell recognition of viral constituents by pattern-recognition receptors (PRRs), induction of IFN-mediated immune responses involving toll-like receptor (TLR) signaling pathways, and cyclic GMP-AMP synthase stimulator of interferon genes (cGAS-STING). This review focuses on these pathways along with other mechanisms including autophagy and the complement system. We will summarize and discuss recent evidence which has revealed how HSV-1 is able to manipulate and evade host antiviral innate immune responses both in neuronal (sensory neurons of the trigeminal ganglia) and non-neuronal (epithelial) cells. Understanding the innate immune response mechanisms triggered by HSV-1 infection, and the mechanisms of innate immune evasion, will impact the development of future therapeutic treatments.


Subject(s)
Axons/immunology , Herpes Simplex/immunology , Herpesvirus 1, Human/immunology , Immune Evasion , Immunity, Innate , Sensory Receptor Cells/immunology , Animals , Herpes Simplex/therapy , Humans , Signal Transduction/immunology
9.
Int J Mol Sci ; 22(8)2021 Apr 08.
Article in English | MEDLINE | ID: mdl-33918103

ABSTRACT

The authors wish to make the following corrections to paper "DNA Methylation Analysis Identifies Patterns in Progressive Glioma Grades to Predict Patient Survival" [...].

10.
Int J Mol Sci ; 22(3)2021 Jan 20.
Article in English | MEDLINE | ID: mdl-33498463

ABSTRACT

DNA methylation is an epigenetic change to the genome that impacts gene activities without modification to the DNA sequence. Alteration in the methylation pattern is a naturally occurring event throughout the human life cycle which may result in the development of diseases such as cancer. In this study, we analyzed methylation data from The Cancer Genome Atlas, under the Lower-Grade Glioma (LGG) and Glioblastoma Multiforme (GBM) projects, to identify methylation markers that exhibit unique changes in DNA methylation pattern along with tumor grade progression, to predict patient survival. We found ten glioma grade-associated Cytosine-phosphate-Guanine (CpG) sites that targeted four genes (SMOC1, KCNA4, SLC25A21, and UPP1) and the methylation pattern is strongly associated with glioma specific molecular alterations, primarily isocitrate dehydrogenase (IDH) mutation and chromosome 1p/19q codeletion. The ten CpG sites collectively distinguished a cohort of diffuse glioma patients with remarkably poor survival probability. Our study highlights genes (KCNA4 and SLC25A21) that were not previously associated with gliomas to have contributed to the poorer patient outcome. These CpG sites can aid glioma tumor progression monitoring and serve as prognostic markers to identify patients diagnosed with less aggressive and malignant gliomas that exhibit similar survival probability to GBM patients.


Subject(s)
Biomarkers, Tumor/genetics , Brain Neoplasms/genetics , DNA Methylation , Glioma/genetics , Brain Neoplasms/pathology , Dicarboxylic Acid Transporters/genetics , Glioma/pathology , Humans , Kv1.4 Potassium Channel/genetics , Middle Aged , Mitochondrial Membrane Transport Proteins/genetics , Osteonectin/genetics , Prognosis , Uridine Phosphorylase/genetics
11.
Front Immunol ; 10: 983, 2019.
Article in English | MEDLINE | ID: mdl-31139180

ABSTRACT

Infiltration of immune cells into the tumor microenvironment (TME) can regulate growth and survival of neoplastic cells, impacting tumorigenesis and tumor progression. Correlations between the number of effector immune cells present in a tumor and clinical outcomes in many human tumors, including breast, have been widely described. Current immunotherapies utilizing checkpoint inhibitors or co-stimulatory molecule agonists aim to activate effector immune cells. However, tumors often lack adequate effector cell numbers within the TME, resulting in suboptimal responses to these agents. Chemerin (RARRES2) is a leukocyte chemoattractant widely expressed in many tissues and is known to recruit innate leukocytes. CMKLR1 is a chemotactic cellular receptor for chemerin and is expressed on subsets of dendritic cells, NK cells, and macrophages. We have previously shown that chemerin acts as a tumor suppressive cytokine in mouse melanoma models by recruiting innate immune defenses into the TME. Chemerin/RARRES2 is down-regulated in many tumors, including breast, compared to normal tissue counterparts. Here, using a syngeneic orthotopic EMT6 breast carcinoma model, we show that forced overexpression of chemerin by tumor cells results in significant recruitment of NK cells and T cells within the TME. While chemerin secretion by EMT6 cells did not alter their phenotypic behavior in vitro, it did significantly suppress tumor growth in vivo. To define the cellular effectors required for this anti-tumor phenotype, we depleted NK cells or CD8+ T cells and found that either cell type is required for chemerin-dependent suppression of EMT6 tumor growth. Finally, we show significantly reduced levels of RARRES2 mRNA in human breast cancer samples compared to matched normal tissues. Thus, for the first time we have shown that increasing chemerin expression within the breast carcinoma TME can suppress growth by recruitment of NK and T cells, thereby supporting this approach as a promising immunotherapeutic strategy.


Subject(s)
Chemokines/immunology , Immunity, Cellular , Intercellular Signaling Peptides and Proteins/immunology , Leukocytes/immunology , Mammary Neoplasms, Animal/immunology , Neoplasm Proteins/immunology , Tumor Microenvironment/immunology , Animals , Female , Gene Expression Regulation, Neoplastic/immunology , Leukocytes/pathology , Mammary Neoplasms, Animal/pathology , Mice , Mice, Inbred BALB C , Mice, Knockout
12.
Front Immunol ; 10: 147, 2019.
Article in English | MEDLINE | ID: mdl-30800123

ABSTRACT

Tumor-associated vascular endothelium comprises a specialized and diverse group of endothelial cells that, although not cancer themselves, are integral to cancer progression. Targeting the tumor vasculature can have significant efficacy in reducing tumor burden, although loss of efficacy due to acquisition of resistance mechanisms is common. Here we review mechanisms by which tumor endothelial cells (TEC) utilize chemokine receptors to support tumor progression. We illustrate how chemokine receptors support and may serve as functional markers of the diverse TEC population. We focus on ACKR1 (DARC), ACKR3 (CXCR7), CXCR4, and CCR2, as these are the best studied chemokine receptors in TEC; and suggest that targeting these receptors on the tumor vasculature may prove efficacious in slowing or reversing tumor growth. We also mention CXCR2 and CXCR3 as important mediators or tumor angiogenesis, given their distinct roles with angiogenic and angiostatic chemokines, respectively.


Subject(s)
Endothelial Cells/immunology , Neoplasms/immunology , Receptors, Chemokine/immunology , Animals , Chemokines/immunology , Humans
13.
Mol Ther ; 26(5): 1354-1365, 2018 05 02.
Article in English | MEDLINE | ID: mdl-29606504

ABSTRACT

Glioblastoma (GBM) is the least treatable type of brain tumor, afflicting over 15,000 people per year in the United States. Patients have a median survival of 16 months, and over 95% die within 5 years. The chemokine receptor ACKR3 is selectively expressed on both GBM cells and tumor-associated blood vessels. High tumor expression of ACKR3 correlates with poor prognosis and potential treatment resistance, making it an attractive therapeutic target. We engineered a single chain FV-human FC-immunoglobulin G1 (IgG1) antibody, X7Ab, to target ACKR3 in human and mouse GBM cells. We used hydrodynamic gene transfer to overexpress the antibody, with efficacy in vivo. X7Ab kills GBM tumor cells and ACKR3-expressing vascular endothelial cells by engaging the cytotoxic activity of natural killer (NK) cells and complement and the phagocytic activity of macrophages. Combining X7Ab with TMZ allows the TMZ dosage to be lowered, without compromising therapeutic efficacy. Mice treated with X7Ab and in combination with TMZ showed significant tumor reduction by MRI and longer survival overall. Brain-tumor-infiltrating leukocyte analysis revealed that X7Ab enhances the activation of M1 macrophages to support anti-tumor immune response in vivo. Targeting ACKR3 with immunotherapeutic monoclonal antibodies (mAbs) in combination with standard of care therapies may prove effective in treating GBM.


Subject(s)
Antibodies, Monoclonal/pharmacology , Glioblastoma/immunology , Glioblastoma/metabolism , Receptors, CXCR/antagonists & inhibitors , Temozolomide/pharmacology , Animals , Antibodies, Monoclonal/metabolism , Antibody Affinity/immunology , Antineoplastic Agents, Immunological/pharmacology , Cell Line, Tumor , Cytotoxicity, Immunologic/drug effects , Disease Models, Animal , Drug Synergism , Glioblastoma/diagnosis , Glioblastoma/mortality , Humans , Magnetic Resonance Imaging , Mice , Mortality , Protein Binding/immunology , Receptors, CXCR/metabolism , Xenograft Model Antitumor Assays
14.
PLoS One ; 11(8): e0161299, 2016.
Article in English | MEDLINE | ID: mdl-27537345

ABSTRACT

BACKGROUND: Medulloblastoma (MB) is the most common pediatric primary malignant brain tumor. Approximately one-third of MB patients succumb to treatment failure and some survivors suffer detrimental side effects. Hence, the purpose of this study is to explore new therapeutic regimens to overcome chemotherapeutic agent resistance or reduce chemotherapy-induced toxicity. METHODS: We detected the expression of inhibitors of apoptosis proteins (IAPs) in MB and CD133+ MB cell lines and MB tissues using immunoblotting and immunohistochemical staining. The antitumor effects of inhibitors against IAPs on MB or CD133+ MB cells were evaluated by MTT assay, Annexin V/PI analysis, and caspase-3/7 activity. Autophagy was assessed by the conversion of light chain (LC) 3-I to LC3-II and Cyto-ID autophagy detection kit. RESULTS: MB cells showed higher expression of IAPs compared to normal astrocytes and normal brain tissues. Conventional chemotherapeutic agents combined with small-molecule IAP inhibitors (LCL161 or LBW242) showed a synergistic effect in MB cells. Combined treatments triggered apoptosis in MB cells through activation of caspase-3/7 and autophagic flux simultaneously. In addition, we found that CD133+ MB cells with features of cancer stem cells displayed higher levels of X-linked inhibitor of apoptosis (XIAP) and cellular inhibitor of apoptosis 1/2 (cIAP1/2), and were hypersensitive to treatment with IAP inhibitors. CONCLUSIONS: These results shed light on the biological effects of combination therapy on MB cells and illustrate that IAP inhibitors are more effective for CD133+ stem-like MB cells.


Subject(s)
Antineoplastic Agents/therapeutic use , Apoptosis/drug effects , Cerebellar Neoplasms/drug therapy , Medulloblastoma/drug therapy , Neoplastic Stem Cells/drug effects , Antineoplastic Agents/administration & dosage , Autophagy/drug effects , Caspase 3/metabolism , Caspase 7/metabolism , Cell Line, Tumor , Cell Survival , Cisplatin/therapeutic use , Drug Synergism , Drug Therapy, Combination , Humans , Oligopeptides/therapeutic use , Thiazoles/therapeutic use , Vincristine/therapeutic use
15.
Mol Cancer Res ; 14(5): 493-503, 2016 05.
Article in English | MEDLINE | ID: mdl-26921391

ABSTRACT

UNLABELLED: The atypical 7-transmembrane chemokine receptor, CXCR7, transactivates the EGFR leading to increased tumor growth in several tumor types. However, the molecular mechanism of CXCR7 ligand-independent EGFR transactivation is unknown. We used cDNA knock-in, RNAi and analysis of mitogenic signaling components in both normal prostate epithelial cells and prostate cancer cells to decipher the proliferation-inducing mechanism of the CXCR7-EGFR interaction. The data demonstrate that CXCR7-induced EGFR transactivation is independent of both the release of cryptic EGFR ligands (e.g., AREG/amphiregulin) and G-protein-coupled receptor signaling. An alternate signaling mechanism involving ß-arrestin-2 (ARRB2/ß-AR2) was examined by manipulating the levels of ß-AR2 and analyzing changes in LNCaP cell growth and phosphorylation of EGFR, ERK1/2, Src, and Akt. Depletion of ß-AR2 in LNCaP cells increased proliferation/colony formation and significantly increased activation of Src, phosphorylation of EGFR at Tyr-1110, and phosphorylation/activation of ERK1/2 compared with that with control shRNA. Moreover, ß-AR2 depletion downregulated the proliferation suppressor p21. Stimulation of ß-AR2-expressing cells with EGF resulted in rapid nuclear translocation of phosphorylated/activated EGFR. Downregulation of ß-AR2 enhanced this nuclear translocation. These results demonstrate that ß-AR2 is a negative regulator of CXCR7/Src/EGFR-mediated mitogenic signaling. IMPLICATIONS: This study reveals that ß-AR2 functions as a tumor suppressor, underscoring its clinical importance in regulating CXCR7/EGFR-mediated tumor cell proliferation. Mol Cancer Res; 14(5); 493-503. ©2016 AACR.


Subject(s)
ErbB Receptors/metabolism , GTP-Binding Proteins/metabolism , Prostatic Neoplasms/metabolism , Receptors, CXCR/genetics , beta-Arrestin 2/genetics , Cell Line , Cell Proliferation , Epithelial Cells/cytology , ErbB Receptors/genetics , Gene Knock-In Techniques , Humans , Male , Mutation , Phosphorylation , RNA Interference , Receptors, CXCR/metabolism , Signal Transduction , beta-Arrestin 2/metabolism
16.
Mol Cancer ; 13: 198, 2014 Aug 28.
Article in English | MEDLINE | ID: mdl-25168820

ABSTRACT

BACKGROUND: Recent advances have revealed a significant contribution of chemokines and their receptors in tumor growth, survival after chemotherapy, and organ-specific metastasis. The CXC chemokine receptor-7 (CXCR7) is the latest chemokine receptor implicated in cancer. Although over expressed in breast cancer cell lines and tumor tissues, its mechanism of action in breast cancer (BrCa) growth and metastasis is unclear. Studies in other cancers have implicated CXCR7 in cell proliferation, anti-apoptotic activity and cell-cell adhesion. The present study was initiated to examine the pattern of CXCR7 expression and its role in regulation of growth signaling in breast cancer. METHODS: The contribution of CXCR7 in BrCa cell proliferation was investigated in representative cell lines using real time quantitative PCR (q-PCR), proliferation assays, immunohistochemistry and immunoblotting. Phenotypic changes were examined after CXCR7 specific cDNA and siRNA transfection and expression levels were monitored by q-PCR. Further, the association of CXCR7 with epidermal growth factor receptor (EGFR) and modulation of its activity were investigated by western blotting, immunofluorescence, and in-situ proximity ligation assays in human BrCa cells and tissues. RESULTS: CXCR7 was expressed in both, estrogen receptor (ER) positive and negative BrCa cell lines. CXCR7 was also expressed unevenly in normal breast tissues and to a much higher extent in ER + cancer tissues. Depletion of CXCR7 in MCF7 BrCa cells by RNA interference decreased proliferation and caused cell cycle arrest. Further, proximity ligation assay (PLA) revealed colocalization of CXCR7 with EGFR in cancer tissues and cancer cell lines. CXCR7 depletion reduced levels of phospho-EGFR at Tyrosine1110 after EGF-stimulation and also reduced phosphorylation of ERK1/2, indicating a potentially direct impact on mitogenic signaling in MCF7 cells. Using siRNA to knockdown ß-arrestin2 in cells with EGFR over expression we were able to nearly deplete the CXCR7-EGFR colocalization events, suggesting that ß-arrestin2 acts as a scaffold to enhance CXCR7 dependent activation of EGFR after EGF stimulation. CONCLUSIONS: These results demonstrate coupling of CXCR7 with EGFR to regulate proliferation of BrCa cells and suggest an important ligand-independent role of CXCR7 in BrCa growth. Thus, the CXCR7-EGFR axis is a promising target for breast cancer therapy.


Subject(s)
Breast Neoplasms/metabolism , Breast Neoplasms/pathology , ErbB Receptors/metabolism , Receptors, CXCR/genetics , Receptors, CXCR/metabolism , Arrestins/genetics , Breast Neoplasms/genetics , Cell Line, Tumor , Cell Proliferation , Female , Gene Knockdown Techniques , Humans , MCF-7 Cells , Mammary Glands, Human/metabolism , Phosphorylation , Signal Transduction , beta-Arrestins
17.
Methods Mol Biol ; 1172: 209-18, 2014.
Article in English | MEDLINE | ID: mdl-24908308

ABSTRACT

In this chapter, we describe a protocol used for stable silencing of chemokine receptor CXCR7 in human cancer cells using shRNA in a lipid transfection setting, previously published by our laboratory. We provide thorough detail and background information about the process of shRNA to clarify the importance of this process. We use CXCR7 shRNA and scrambled sequence shRNA constructs cloned into a pRS plasmid under the control of a U6 promoter for stable expression. Human cancer cells are transfected with shRNA-pRS using Lipofectamine 2000. Cells stably expressing the shRNA are selected from transfected cultures following 2 weeks in medium containing the selection antibiotic puromycin. The emergent cell colonies are evaluated for knockdown of CXCR7 mRNA and protein expression by q-PCR and immunoblotting with rabbit anti-CXCR7 IgG, respectively.


Subject(s)
Gene Expression , RNA, Small Interfering/genetics , Receptors, CXCR/genetics , Animals , Antibodies/chemistry , Blotting, Western , Cell Line, Tumor , Clone Cells , Humans , Lipids/chemistry , Plasmids/chemistry , Promoter Regions, Genetic , RNA, Small Interfering/metabolism , Rabbits , Receptors, CXCR/antagonists & inhibitors , Receptors, CXCR/metabolism , Transfection
18.
Crit Rev Eukaryot Gene Expr ; 23(1): 77-91, 2013.
Article in English | MEDLINE | ID: mdl-23557339

ABSTRACT

Prostate cancer (CaP) is estimated to be first in incidence among cancers, with more than 240,000 new cases in 2012 in the United States. Chemokines and their receptors provide survival, proliferation, and invasion characteristics to CaP cells in both primary sites of cancer and metastatic locations. The emerging data demonstrate that many chemokines and their receptors are involved in the multistep process of CaP, leading to metastasis, and, further, that these factors act cooperatively to enhance other mechanisms of tumor cell survival, growth, and metastasis. Changes of chemokine receptor cohorts may be necessary to activate tumor-promoting signals. Chemokine receptors can activate downstream effectors, such as mitogen-activated protein kinases, by complex mechanisms of ligand-dependent activation of cryptic growth factors; guanosine triphosphate-binding, protein-coupled activation of survival kinases; or transactivation of other receptors such as ErbB family members. We describe vanguard research in which more than the classic view of chemokine receptor biology was clarified. Control of chemokines and inhibition of their receptor activation may add critical tools to reduce tumor growth, especially in chemo-hormonal refractory CaP that is both currently incurable and the most aggressive form of the disease, accounting for most of the more than 28,000 annual deaths.


Subject(s)
Cell Transformation, Neoplastic , Chemokines/metabolism , Prostatic Neoplasms/genetics , Receptors, Chemokine/metabolism , Cell Survival , Disease Progression , Gene Expression Regulation, Neoplastic , Humans , Male , Neoplasm Metastasis , Prostatic Neoplasms/metabolism , Prostatic Neoplasms/pathology , Receptors, Chemokine/antagonists & inhibitors , Signal Transduction
19.
J Crit Care ; 28(4): 451-60, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23337487

ABSTRACT

PURPOSE: Medication errors (MEs) are a major factor limiting the effectiveness and safety of pharmacological therapies in critically ill patients. The purpose was to determine if a preventive interventions program (PIP) is associated with a significant reduction on prevalence of patients with MEs in intensive care unit (ICU). METHODS: A prospective before-after study was conducted in a random sample of adult patients in a medical-surgical ICU. Between 2 observational phases, a PIP (bundle of interventions to reduce MEs) was implemented by a multidisciplinary team. Direct observation was used to detect MEs at baseline and postintervention. Each medication process, that is, prescription, transcription, dispensing, preparation, and administration, was compared with what the prescriber ordered; if there was a difference, the error was described and categorized. Medication errors were defined according to the National Coordinating Council for Medication Error Reporting and Prevention. RESULTS: A total of 410 medications for 278 patients were evaluated. A 31.7% decrease on the prevalence of patients with MEs (41.9%-28.6%; P < .05) was seen. Main variations occurred in anti-infectives for systemic use and prescription and administration stage. CONCLUSIONS: The implementation of PIP by a multidisciplinary team resulted in a significant reduction on the prevalence of patients with ME at an adult ICU.


Subject(s)
Critical Illness , Intensive Care Units , Medication Errors/prevention & control , Medication Errors/statistics & numerical data , Patient Care Team/organization & administration , Chi-Square Distribution , Female , Humans , Inservice Training , Male , Middle Aged , Patient Safety , Prevalence , Prospective Studies
20.
Rev. chil. med. intensiv ; 27(1): 15-22, 2012. tab
Article in Spanish | LILACS | ID: lil-669014

ABSTRACT

La seguridad de los pacientes críticos en la Unidad de Cuidados Intensivos (UCI), ha sido progresivamente reconocida como un componente esencial de la práctica de la medicina intensiva moderna. La creación y promoción de equipos multidisciplinarios liderados por un intensivista ha demostrado mejorar la seguridad de la atención de salud. La incorporación de un farmacéutico con entrenamiento especializado a la UCI, ha generado un impacto positivo en los desenlaces clínicos y económicos. El fomento de la cultura de la seguridad en la UCI y el rediseño de los procesos defectuosos pueden mejorar significativamente la seguridad y calidad de la atención de los pacientes críticos.


The safety of critically ill patients in Intensive Care Unit (ICU) has been increasingly recognized as an essential component of the practice of modern intensive care. The creation and promotion of intensivist-led multidisciplinary teams has shown to improve the safety of health care. The addition in the ICU of a pharmacist with specialized training has generated a positive impact on clinical and economic outcomes. The promotion of safety culture in the ICU and the redesign of faulty processes can significantly improve the safety and quality of care of critically ill patients.


Subject(s)
Humans , Pharmacists/organization & administration , Patient Care Team , Intensive Care Units/organization & administration , Critical Illness , Critical Care/organization & administration , Medication Errors/prevention & control , Pharmaceutical Services , Quality Control , Safety , Pharmacy Service, Hospital/organization & administration
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