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Lai B, Lai Y, Zhang Y, Zhou M, OuYang G. Survival prediction in acute myeloid leukemia using gene expression profiling. BMC Med Inform Decis Mak 2022; 22:57. [PMID: 35241089 PMCID: PMC8892720 DOI: 10.1186/s12911-022-01791-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 02/25/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Acute myeloid leukemia (AML) is a genetically heterogeneous blood disorder. AML patients are associated with a relatively poor overall survival. The objective of this study was to establish a machine learning model to accurately perform the prognosis prediction in AML patients. METHODS We first screened for prognosis-related genes using Kaplan-Meier survival analysis in The Cancer Genome Atlas dataset and validated the results in the Oregon Health & Science University dataset. With a random forest model, we built a prognostic risk score using patient's age, TP53 mutation, ELN classification and normalized 197 gene expression as predictor variable. Gene set enrichment analysis was implemented to determine the dysregulated gene sets between the high-risk and low-risk groups. Similarity Network Fusion (SNF)-based integrative clustering was performed to identify subgroups of AML patients with different clinical features. RESULTS The random forest model was deemed the best model (area under curve value, 0.75). The random forest-derived risk score exhibited significant association with shorter overall survival in AML patients. The gene sets of pantothenate and coa biosynthesis, glycerolipid metabolism, biosynthesis of unsaturated fatty acids were significantly enriched in phenotype high risk score. SNF-based integrative clustering indicated three distinct subsets of AML patients in the TCGA cohort. The cluster3 AML patients were characterized by older age, higher risk score, more frequent TP53 mutations, higher cytogenetics risk, shorter overall survival. CONCLUSIONS The random forest-based risk score offers an effective method to perform prognosis prediction for AML patients.
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Affiliation(s)
- Binbin Lai
- Department of Hematology, Ningbo First Hospital, 59 Liuting Road, Ningbo, 315000, Zhejiang Province, China
| | - Yanli Lai
- Department of Hematology, Ningbo First Hospital, 59 Liuting Road, Ningbo, 315000, Zhejiang Province, China
| | - Yanli Zhang
- Department of Hematology, Ningbo First Hospital, 59 Liuting Road, Ningbo, 315000, Zhejiang Province, China
| | - Miao Zhou
- Department of Hematology, Ningbo First Hospital, 59 Liuting Road, Ningbo, 315000, Zhejiang Province, China
| | - Guifang OuYang
- Department of Hematology, Ningbo First Hospital, 59 Liuting Road, Ningbo, 315000, Zhejiang Province, China.
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Tsai MJ, Chang WA, Chuang CH, Wu KL, Cheng CH, Sheu CC, Hsu YL, Hung JY. Cysteinyl Leukotriene Pathway and Cancer. Int J Mol Sci 2021; 23:ijms23010120. [PMID: 35008546 PMCID: PMC8745400 DOI: 10.3390/ijms23010120] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 12/18/2021] [Accepted: 12/21/2021] [Indexed: 02/06/2023] Open
Abstract
Cancer remains a leading cause of death worldwide, despite many advances being made in recent decades. Changes in the tumor microenvironment, including dysregulated immunity, may contribute to carcinogenesis and cancer progression. The cysteinyl leukotriene (CysLT) pathway is involved in several signal pathways, having various functions in different tissues. We summarized major findings of studies about the roles of the CysLT pathway in cancer. Many in vitro studies suggested the roles of CysLTs in cell survival/proliferation via CysLT1 receptor (CysLT1R). CysLT1R antagonism decreased cell vitality and induced cell death in several types of cancer cells, such as colorectal, urological, breast, lung and neurological malignancies. CysLTs were also associated with multidrug resistance of cancer, and CysLT1R antagonism might reverse chemoresistance. Some animal studies demonstrated the beneficial effects of CysLT1R antagonist in inhibiting tumorigenesis and progression of some cancer types, particularly colorectal cancer and lung cancer. The expression of CysLT1R was shown in various cancer tissues, particularly colorectal cancer and urological malignancies, and higher expression was associated with a poorer prognosis. The chemo-preventive effects of CysLT1R antagonists were demonstrated in two large retrospective cohort studies. In summary, the roles of the CysLT pathway in cancer have been delineated, whereas further studies are still warranted.
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Affiliation(s)
- Ming-Ju Tsai
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (M.-J.T.); (W.-A.C.); (C.-H.C.); (K.-L.W.); (C.-H.C.); (C.-C.S.)
- School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Department of Respiratory Care, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Wei-An Chang
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (M.-J.T.); (W.-A.C.); (C.-H.C.); (K.-L.W.); (C.-H.C.); (C.-C.S.)
- School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Department of Respiratory Care, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Cheng-Hao Chuang
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (M.-J.T.); (W.-A.C.); (C.-H.C.); (K.-L.W.); (C.-H.C.); (C.-C.S.)
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan;
| | - Kuan-Li Wu
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (M.-J.T.); (W.-A.C.); (C.-H.C.); (K.-L.W.); (C.-H.C.); (C.-C.S.)
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan;
| | - Chih-Hung Cheng
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (M.-J.T.); (W.-A.C.); (C.-H.C.); (K.-L.W.); (C.-H.C.); (C.-C.S.)
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan;
| | - Chau-Chyun Sheu
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (M.-J.T.); (W.-A.C.); (C.-H.C.); (K.-L.W.); (C.-H.C.); (C.-C.S.)
- School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Department of Respiratory Care, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Ya-Ling Hsu
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan;
| | - Jen-Yu Hung
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (M.-J.T.); (W.-A.C.); (C.-H.C.); (K.-L.W.); (C.-H.C.); (C.-C.S.)
- School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Department of Respiratory Care, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Department of Internal Medicine, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Correspondence: ; Tel.: +886-7-3121101 (ext. 5651)
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Targeting cPLA2α inhibits gastric cancer and augments chemotherapy efficacy via suppressing Ras/MEK/ERK and Akt/β-catenin pathways. Cancer Chemother Pharmacol 2021; 88:689-697. [PMID: 34255137 DOI: 10.1007/s00280-021-04322-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Accepted: 07/05/2021] [Indexed: 01/06/2023]
Abstract
BACKGROUND Cytosolic phospholipase A2alpha (cPLA2α), an enzyme that is responsible for the hydrolysis of membrane phospholipids, is a key mediator of tumor transformation, progression and metastasis. The role of cPLA2α in gastric cancer has not been revealed. METHODS cPLA2α expression was analyzed using RT-PCR and immunohistochemistry approaches in gastric cancer patient samples (n = 26) and multiple cell lines (n = 7). cPLA2α function was studied using plasmid overexpression and siRNA knockdown approaches in SNU-1, MKN-74 and MKN-45 cell lines. The downstream effectors of cPLA2α were determined using biochemical assays. RESULTS cPLA2α upregulation is a common feature in gastric cancer patients, particularly those with metastasis. cPLA2α overexpression is sufficient to promote gastric cancer cell growth and migration, and confer chemo-resistance. cPLA2α depletion is active against gastric cancer via inhibiting growth and migration, and inducing apoptosis in gastric cancer cells. Of note, cPLA2α depletion augments efficacy of chemotherapy. Mechanistic studies confirm that cPLA2α regulates gastric cancer biological activities via mainly regulating Ras/MEK/ERK and possibly Akt/β-catenin pathways. Pearson correlation coefficient analysis also suggests a moderate positive correlation between cPLA2α and RAS in gastric cancer. CONCLUSIONS Our work demonstrates cPLA2α inhibition as a therapeutic strategy to overcome chemo-resistance and highlights the association of cPLA2α and Ras in gastric cancer.
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Lai Y, Sheng L, Wang J, Zhou M, OuYang G. A Novel 85-Gene Expression Signature Predicts Unfavorable Prognosis in Acute Myeloid Leukemia. Technol Cancer Res Treat 2021; 20:15330338211004933. [PMID: 33784904 PMCID: PMC8020099 DOI: 10.1177/15330338211004933] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Aim: Acute myeloid leukemia (AML) is a heterogeneous disorder with complex genetic
basis and adverse prognosis. Cytogenetics risk, somatic mutations and gene
expression profiles are important prognostic factors for AML patients.
However, accurate stratification of patient prognosis remains an unsolved
problem in AML. This study was to to develop a novel gene profile to
accurately classify AML patients into subgroups with different survival
probabilities. Methods: Survival-related genes were determined by Kaplan–Meier survival analysis and
multivariate analysis using the expression and clinical data of 405 AML
patients from Oregon Health & Science University (OHSU) dataset and
validated in The Cancer Genome Atlas (TCGA) database. Feature selection was
performed by using the Least Absolute Shrinkage and Selection Operator
(LASSO) method. With the LASSO model, a prognostic 85-gene score was
established and compared with 2 known gene-expression risk scores. The
stratification of AML patients was performed by unsupervised hierarchical
clustering of 85 gene expression levels to identify clusters of AML patients
with different survival probabilities. Results: The LASSO model comprising 85 genes was considered as the optimal model based
on relatively high area under curve value (0.83) and the minimum mean
squared error. The 85-gene score was associated with increased mortality in
AML patients. Hierarchical clustering analysis of the 85 genes revealed 3
subgroups of AML patients in the OHSU dataset. The cluster1 AML patients
were associated with more female cases, higher percent of bone marrow blast
cells, 85-gene score, cytogenetics risk, more frequent FLT3-ITD,
DNMT3A, NP1 mutations, less frequent
TP53, RUNX1 mutations, poorer overall
survival than cluster2 tumors. The 85-gene score had higher AUC (0.75) than
the 5-gene risk score and LSC17 score (0.74 and 0.65). Conclusions: The 85-gene score is superior to the 2 established prognostic gene signatures
in the prediction of prognosis of AML patients.
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Affiliation(s)
- Yanli Lai
- Department of Hematology, Ningbo First Hospital, Ningbo, Zhejiang Province, China
| | - Lixia Sheng
- Department of Hematology, Ningbo First Hospital, Ningbo, Zhejiang Province, China
| | - Jiaping Wang
- Department of Hematology, Ningbo First Hospital, Ningbo, Zhejiang Province, China
| | - Miao Zhou
- Department of Hematology, Ningbo First Hospital, Ningbo, Zhejiang Province, China
| | - Guifang OuYang
- Department of Hematology, Ningbo First Hospital, Ningbo, Zhejiang Province, China
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Lai Y, OuYang G, Sheng L, Zhang Y, Lai B, Zhou M. Novel prognostic genes and subclasses of acute myeloid leukemia revealed by survival analysis of gene expression data. BMC Med Genomics 2021; 14:39. [PMID: 33536020 PMCID: PMC7860023 DOI: 10.1186/s12920-021-00888-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 01/27/2021] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Acute myeloid leukemia (AML) is biologically heterogeneous diseases with adverse prognosis. This study was conducted to find prognostic biomarkers that could effectively classify AML patients and provide guidance for treatment decision making. METHODS Weighted gene co-expression network analysis was applied to detect co-expression modules and analyze their relationship with clinicopathologic characteristics using RNA sequencing data from The Cancer Genome Atlas database. The associations of gene expression with patients' mortality were investigated by a variety of statistical methods and validated in an independent dataset of 405 AML patients. A risk score formula was created based on a linear combination of five gene expression levels. RESULTS The weighted gene co-expression network analysis detected 63 co-expression modules. The pink and darkred modules were negatively significantly correlated with overall survival of AML patients. High expression of FNDC3B, VSTM1 and CALR was associated with favourable overall survival, while high expression of PLA2G4A was associated with adverse overall survival. Hierarchical clustering analysis of FNDC3B, VSTM1, PLA2G4A, GOLGA3 and CALR uncovered four subgroups of AML patients. The cluster1 AML patients showed younger age, lower cytogenetics risk, higher frequency of NPM1 mutations and more favourable overall survival than cluster3 patients. The risk score was demonstrated to be an indicator of adverse prognosis in AML patients CONCLUSIONS: The FNDC3B, VSTM1, PLA2G4A, GOLGA3, CALR and risk score may serve as key prognostic biomarkers for the stratification and ultimately guide rational treatment of AML patients.
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Affiliation(s)
- Yanli Lai
- Department of Hematology, Ningbo First Hospital, 59 Liuting RoadZhejiang Province, Ningbo, 315000, China
| | - Guifang OuYang
- Department of Hematology, Ningbo First Hospital, 59 Liuting RoadZhejiang Province, Ningbo, 315000, China
| | - Lixia Sheng
- Department of Hematology, Ningbo First Hospital, 59 Liuting RoadZhejiang Province, Ningbo, 315000, China
| | - Yanli Zhang
- Department of Hematology, Ningbo First Hospital, 59 Liuting RoadZhejiang Province, Ningbo, 315000, China
| | - Binbin Lai
- Department of Hematology, Ningbo First Hospital, 59 Liuting RoadZhejiang Province, Ningbo, 315000, China
| | - Miao Zhou
- Department of Hematology, Ningbo First Hospital, 59 Liuting RoadZhejiang Province, Ningbo, 315000, China.
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6
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Sha K, Lu Y, Zhang P, Pei R, Shi X, Fan Z, Chen L. Identifying a novel 5-gene signature predicting clinical outcomes in acute myeloid leukemia. Clin Transl Oncol 2020; 23:648-656. [PMID: 32776271 DOI: 10.1007/s12094-020-02460-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 07/11/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Acute myeloid leukemia (AML) is the most common type of acute leukemia and biologically heterogeneous diseases with poor prognosis. Thus, we aimed to identify prognostic markers to effectively predict the prognosis of AML patients and eventually guide treatment. METHODS Prognosis-associated genes were determined by Kaplan-Meier and multivariate analyses using the expression and clinical data of 173 AML patients from The Cancer Genome Atlas database and validated in an independent Oregon Health and Science University dataset. A prognostic risk score was computed based on a linear combination of 5-gene expression levels using the regression coefficients derived from the multivariate logistic regression model. The classification of AML was established by unsupervised hierarchical clustering of CALCRL, DOCK1, PLA2G4A, FCHO2 and LRCH4 expression levels. RESULTS High FCHO2 and LRCH4 expression was related to decreased mortality. While high CALCRL, DOCK1, PLA2G4A expression was associated with increased mortality. The risk score was predictive of increased mortality rate in AML patients. Hierarchical clustering analysis of the five genes discovered three clusters of AML patients. The cluster1 AML patients were associated with lower cytogenetics risk than cluster2 or 3 patients, and better prognosis than cluster3 patients (P values < 0.05 for all cases, fisher exact test or log-rank test). CONCLUSION The gene panel comprising CALCRL, DOCK1, PLA2G4A, FCHO2 and LRCH4 as well as the risk score may offer novel prognostic biomarkers and classification of AML patients to significantly improve outcome prediction.
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Affiliation(s)
- K Sha
- Department of Hematology, The Affiliated People's Hospital of Ningbo University, No. 251, East Baizhang Road, Ningbo, 315000, Zhejiang, China.
| | - Y Lu
- Department of Hematology, The Affiliated People's Hospital of Ningbo University, No. 251, East Baizhang Road, Ningbo, 315000, Zhejiang, China
| | - P Zhang
- Department of Hematology, The Affiliated People's Hospital of Ningbo University, No. 251, East Baizhang Road, Ningbo, 315000, Zhejiang, China
| | - R Pei
- Department of Hematology, The Affiliated People's Hospital of Ningbo University, No. 251, East Baizhang Road, Ningbo, 315000, Zhejiang, China
| | - X Shi
- Department of Hematology, The Affiliated People's Hospital of Ningbo University, No. 251, East Baizhang Road, Ningbo, 315000, Zhejiang, China
| | - Z Fan
- Department of Hematology, The Affiliated People's Hospital of Ningbo University, No. 251, East Baizhang Road, Ningbo, 315000, Zhejiang, China
| | - L Chen
- Department of Hematology, The Affiliated People's Hospital of Ningbo University, No. 251, East Baizhang Road, Ningbo, 315000, Zhejiang, China
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7
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Das UN. Can Bioactive Lipids Augment Anti-cancer Action of Immunotherapy and Prevent Cytokine Storm? Arch Med Res 2019; 50:342-349. [DOI: 10.1016/j.arcmed.2019.10.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 10/18/2019] [Indexed: 12/31/2022]
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Nikolaou A, Kokotou MG, Vasilakaki S, Kokotos G. Small-molecule inhibitors as potential therapeutics and as tools to understand the role of phospholipases A 2. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:941-956. [PMID: 30905350 PMCID: PMC7106526 DOI: 10.1016/j.bbalip.2018.08.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/10/2018] [Accepted: 08/16/2018] [Indexed: 11/20/2022]
Abstract
Phospholipase A2 (PLA2) enzymes are involved in various inflammatory pathological conditions including arthritis, cardiovascular and autoimmune diseases. The regulation of their catalytic activity is of high importance and a great effort has been devoted in developing synthetic inhibitors. We summarize the most important small-molecule synthetic PLA2 inhibitors developed to target each one of the four major types of human PLA2 (cytosolic cPLA2, calcium-independent iPLA2, secreted sPLA2, and lipoprotein-associated LpPLA2). We discuss recent applications of inhibitors to understand the role of each PLA2 type and their therapeutic potential. Potent and selective PLA2 inhibitors have been developed. Although some of them have been evaluated in clinical trials, none reached the market yet. Apart from their importance as potential medicinal agents, PLA2 inhibitors are excellent tools to unveil the role that each PLA2 type plays in cells and in vivo. Modern medicinal chemistry approaches are expected to generate improved PLA2 inhibitors as new agents to treat inflammatory diseases.
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Affiliation(s)
- Aikaterini Nikolaou
- Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, Athens 15771, Greece
| | - Maroula G Kokotou
- Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, Athens 15771, Greece
| | - Sofia Vasilakaki
- Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, Athens 15771, Greece
| | - George Kokotos
- Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, Athens 15771, Greece.
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Xu H, Sun Y, Zeng L, Li Y, Hu S, He S, Chen H, Zou Q, Luo B. Inhibition of cytosolic phospholipase A2 alpha increases chemosensitivity in cervical carcinoma through suppressing β-catenin signaling. Cancer Biol Ther 2019; 20:912-921. [PMID: 30829552 DOI: 10.1080/15384047.2019.1579961] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Cytosolic phospholipase A2alpha (cPLA2α) is a key mediator of tumorigenesis. In this study, by using a combination of pharmacological and genetic approaches in cell models and patient samples, we identify cPLA2α as a selective target to increase chemosensitivity in cervical cancer. We found that transcript and protein levels of cPLA2α but not other forms of cPLA2 (e.g., cPLA2β and cPLA2αδ) were consistently increased in all tested malignant cervical cancer cells and tissues compared to normal counterparts, suggesting that cPLA2α upregulation is a common feature in cervical cancer. We further found that promoting growth and survival rather than invasion were the predominant roles of cPLA2α on cervical cancer. In addition, chemotherapeutic agents achieved ~100% inhibition efficacy in cPLA2α-depleted cervical cancer cells, demonstrating the important role of cPLA2α in chemoresistance. Importantly, we identify that β-catenin is critically involved in the molecular mechanism of cPLA2α's action in cervical cancer. In summary, our work demonstrates the multiple essential roles of cPLA2α in cervical cancer, particularly in chemoresistance, via a β-catenin-dependent manner. Our work also suggests that targeting cPLA2α has a therapeutic value in overcoming chemoresistance in cervical cancer or other cPLA2α-regulated cancers.
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Affiliation(s)
- Hai Xu
- a Department of Obstetrics and Gynaecology, Huangjiahu Hospital of Hubei University of Chinese Medicine , Wuhan , China
| | - Yuan Sun
- b College of Pharmacy , Hubei University of Chinese Medicine , Wuhan , China
| | - Lan Zeng
- c Clinical College of Chinese Medicine , Hubei University of Chinese Medicine , Wuhan , China
| | - Ying Li
- a Department of Obstetrics and Gynaecology, Huangjiahu Hospital of Hubei University of Chinese Medicine , Wuhan , China
| | - Shan Hu
- a Department of Obstetrics and Gynaecology, Huangjiahu Hospital of Hubei University of Chinese Medicine , Wuhan , China
| | - Shuping He
- a Department of Obstetrics and Gynaecology, Huangjiahu Hospital of Hubei University of Chinese Medicine , Wuhan , China
| | - Haixia Chen
- a Department of Obstetrics and Gynaecology, Huangjiahu Hospital of Hubei University of Chinese Medicine , Wuhan , China
| | - Qing Zou
- d Department of Clinical Medicine, Huangshi Puren Hospital , Huangshi , China
| | - Baoping Luo
- e Department of Oncology , Hubei Provincial Hospital of Traditional Chinese Medicine , Wuhan , China
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Expression of Cytosolic Phospholipase A2 Alpha in Glioblastoma Is Associated With Resistance to Chemotherapy. Am J Med Sci 2018; 356:391-398. [PMID: 30360807 DOI: 10.1016/j.amjms.2018.06.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Revised: 06/17/2018] [Accepted: 06/19/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND The clinical management of glioblastoma is still challenging despite aggressive surgery and radio-chemotherapy approaches. Better understanding of the molecules involved in glioblastoma chemoresistance is necessary to improve the treatment and predict prognosis. MATERIALS AND METHODS We analyzed the expression and possible roles of cytosolic phospholipase A2 alpha (cPLA2α) in human glioblastoma cell lines and patient samples using immunohistochemistry and cellular assays. We analyzed the signaling pathways that cPLA2α regulates in glioblastoma cells using western blot analysis. RESULTS Our work demonstrated that cPLA2α is upregulated in glioblastoma compared with normal neuron cells. The expression of cPLA2α varies in multiple glioblastoma cell lines and is associated with chemoresistance rather than tumor development. cPLA2α depletion moderately inhibits glioblastoma growth and survival but remarkably sensitizes chemo-resistant glioblastoma cells to several chemotherapeutic agents. Mechanistically, cPLA2α knockdown significantly suppresses the PI3K/Akt/mTOR pathway in glioblastoma cells. CONCLUSIONS We are the first to identify the important role of cPLA2α in glioblastoma in response to chemotherapy. Our data also suggest that cPLA2α may serve as a biomarker to indicate prognosis of glioblastoma patients with high level of cPLA2α to chemotherapy.
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Blockage of cytosolic phospholipase A2 alpha sensitizes aggressive breast cancer to doxorubicin through suppressing ERK and mTOR kinases. Biochem Biophys Res Commun 2018; 496:153-158. [PMID: 29307829 DOI: 10.1016/j.bbrc.2018.01.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Accepted: 01/03/2018] [Indexed: 02/02/2023]
Abstract
Advanced breast cancer is resistant to chemotherapy and its underlying mechanisms are not fully explored. In this work, we identified cytosolic phospholipase A2 alpha (cPLA2α) as a novel target to overcome chemoresistance in breast cancer. We demonstrated the increased transcriptional and translational expression of cPLA2α in breast cancer cells to acute and chronic exposure to doxorubicin. cPLA2α upregulation is also observed in breast cancer patients in response to chemotherapy. Inhibition of cPLA2α using two pharmacological inhibitors significantly enhances doxorubicin's effects to almost complete suppression in breast cancer cell growth, survival and migration. Similarly, depletion of cPLA2α significantly sensitizes breast cancer cells to doxorubicin treatment. We further found that cPLA2α inhibition led to decreased phosphorylation of ERK, mTOR, S6 and 4EBP1, suggesting the suppression of ERK and mTOR signaling pathways. These findings indicate the positive roles of cPLA2α in breast cancer cell growth, survival, migration and response to chemotherapy. Our work also highlights the therapeutic value of blocking cPLA2α to overcome chemoresistance in breast cancer.
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12
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Molecular mechanisms of target recognition by lipid GPCRs: relevance for cancer. Oncogene 2015; 35:4021-35. [DOI: 10.1038/onc.2015.467] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 11/02/2015] [Accepted: 11/02/2015] [Indexed: 12/18/2022]
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Zheng Z, He X, Xie C, Hua S, Li J, Wang T, Yao M, Vignarajan S, Teng Y, Hejazi L, Liu B, Dong Q. Targeting cytosolic phospholipase A2 α in colorectal cancer cells inhibits constitutively activated protein kinase B (AKT) and cell proliferation. Oncotarget 2015; 5:12304-16. [PMID: 25365190 PMCID: PMC4322978 DOI: 10.18632/oncotarget.2639] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 10/28/2014] [Indexed: 01/05/2023] Open
Abstract
A constitutive activation of protein kinase B (AKT) in a hyper-phosphorylated status at Ser473 is one of the hallmarks of anti-EGFR therapy-resistant colorectal cancer (CRC). The aim of this study was to examine the role of cytosolic phospholipase A2α (cPLA2α) on AKT phosphorylation at Ser473 and cell proliferation in CRC cells with mutation in phosphoinositide 3-kinase (PI3K). AKT phosphorylation at Ser473 was resistant to EGF stimulation in CRC cell lines of DLD-1 (PIK3CAE545K mutation) and HT-29 (PIK3CAP499T mutation). Over-expression of cPLA2α by stable transfection increased basal and EGF-stimulated AKT phosphorylation and proliferation in DLD-1 cells. In contrast, silencing of cPLA2α with siRNA or inhibition with Efipladib decreased basal and EGF-stimulated AKT phosphorylation and proliferation in HT-29. Treating animals transplanted with DLD-1 with Efipladib (10 mg/kg, i.p. daily) over 14 days reduced xenograft growth by >90% with a concomitant decrease in AKT phosphorylation. In human CRC tissue, cPLA2α expression and phosphorylation were increased in 63% (77/120) compared with adjacent normal mucosa determined by immunohistochemistry. We conclude that cPLA2α is required for sustaining AKT phosphorylation at Ser473 and cell proliferation in CRC cells with PI3K mutation, and may serve as a potential therapeutic target for treatment of CRC resistant to anti-EGFR therapy.
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Affiliation(s)
- Zhong Zheng
- Department of Gynecologic Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Xiangyi He
- Department of Gastroenterology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Chanlu Xie
- Central Clinical School and Bosch Institute, The University of Sydney and Department of Endocrinology and Sydney Cancer Centre, Royal Prince Alfred Hospital, Sydney, Australia. School of Science and Health, The University of Western Sydney, Australia
| | - Sheng Hua
- Central Clinical School and Bosch Institute, The University of Sydney and Department of Endocrinology and Sydney Cancer Centre, Royal Prince Alfred Hospital, Sydney, Australia
| | - Jianfang Li
- Shanghai Key Laboratory of Gastric Neoplasms, Department of Surgery, Shanghai Institute of Digestive Surgery, and Gastroenterology, Ruijin Hospital, Jiaotong University School of Medicine, Shanghai, China
| | - Tingfeng Wang
- Department of General Surgery, Nanhui Central Hospital. Shanghai, China
| | - Mu Yao
- Central Clinical School and Bosch Institute, The University of Sydney and Department of Endocrinology and Sydney Cancer Centre, Royal Prince Alfred Hospital, Sydney, Australia
| | - Soma Vignarajan
- Central Clinical School and Bosch Institute, The University of Sydney and Department of Endocrinology and Sydney Cancer Centre, Royal Prince Alfred Hospital, Sydney, Australia
| | - Ying Teng
- Central Clinical School and Bosch Institute, The University of Sydney and Department of Endocrinology and Sydney Cancer Centre, Royal Prince Alfred Hospital, Sydney, Australia
| | - Leila Hejazi
- Central Clinical School and Bosch Institute, The University of Sydney and Department of Endocrinology and Sydney Cancer Centre, Royal Prince Alfred Hospital, Sydney, Australia. School of Science and Health, The University of Western Sydney, Australia
| | - Bingya Liu
- Shanghai Key Laboratory of Gastric Neoplasms, Department of Surgery, Shanghai Institute of Digestive Surgery, and Gastroenterology, Ruijin Hospital, Jiaotong University School of Medicine, Shanghai, China
| | - Qihan Dong
- Central Clinical School and Bosch Institute, The University of Sydney and Department of Endocrinology and Sydney Cancer Centre, Royal Prince Alfred Hospital, Sydney, Australia. School of Science and Health, The University of Western Sydney, Australia
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14
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Cabral M, Martín-Venegas R, Moreno JJ. Leukotriene D4-induced Caco-2 cell proliferation is mediated by prostaglandin E2 synthesis. Physiol Rep 2015. [PMID: 26216432 PMCID: PMC4552517 DOI: 10.14814/phy2.12417] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Leukotriene D4 (LTD4) is a pro-inflammatory mediator formed from arachidonic acid through the action of 5-lipoxygenase (5-LOX). Its biological effects are mediated by at least two G-coupled plasmatic cysteinyl LT receptors (CysLT1-2R). It has been reported an upregulation of the 5-LOX pathway in tumor tissue unlike in normal colon mucosa. Colon tumors generally have an increased expression of CysLT1R and colon cancer patients with high expression levels of CysLT1R have poor prognosis. We previously observed that the cyclooxygenase pathway is involved in the control of intestinal epithelial cancer cell growth through PGE2 production. The aim of this study was therefore to assess the effect of LTD4 binding with CysLT1R on Caco-2 cell growth. We note a number of key findings from this research. We observed that at a concentration similar to that found under inflammatory conditions, LTD4 was able to induce Caco-2 cell proliferation and DNA synthesis. Moreover, with the use of a specific receptor antagonist this study has demonstrated that the effect of LTD4 is a result of its interaction with CystLT1R. We also note the possible participation of the PLC-IP3-Ca2+/DAG-PKC signaling pathways in cytosolic PLA2 and [3H]AA release induced by LTD4-CystLT1R interaction. Finally, we found that the resulting activation of the AA cascade and the production of PGE2 eicosanoid could be related to the activation of cell signaling pathways such as ERK and CREB. These findings will help facilitate our understanding of how inflammatory mediators can affect the survival and dissemination of intestinal carcinoma cells.
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Affiliation(s)
- Marisol Cabral
- Departament de Fisiologia, Facultat de Farmàcia, Universitat de Barcelona, Barcelona, Spain
| | - Raquel Martín-Venegas
- Departament de Fisiologia, Facultat de Farmàcia, Universitat de Barcelona, Barcelona, Spain
| | - Juan J Moreno
- Departament de Fisiologia, Facultat de Farmàcia, Universitat de Barcelona, Barcelona, Spain
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15
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Bäck M, Dahlén SE, Drazen JM, Evans JF, Serhan CN, Shimizu T, Yokomizo T, Rovati GE. International Union of Basic and Clinical Pharmacology. LXXXIV: Leukotriene Receptor Nomenclature, Distribution, and Pathophysiological Functions. Pharmacol Rev 2011; 63:539-84. [DOI: 10.1124/pr.110.004184] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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16
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Tian G, Wang X, Zhang F, Geng H, Hou W, Chen L, Guo H, Zhang N. Downregulation of cPLA2γ expression inhibits EGF-induced chemotaxis of human breast cancer cells through Akt pathway. Biochem Biophys Res Commun 2011; 409:506-12. [PMID: 21600875 DOI: 10.1016/j.bbrc.2011.05.035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 05/05/2011] [Indexed: 01/06/2023]
Abstract
Phospholipids play an important role in mediating cell migration. In the present study, we investigated the role of cPLA(2)γ in chemotaxis of human breast cancer cells. Inhibition of cPLA(2)γ expression by small interference RNA severely inhibits EGF-induced chemotaxis in a dose-dependent manner in MDA-MB-231, MCF-7, T47D and ZR-75-30 cells. Furthermore, silencing cPLA(2)γ expression also impaired directional migration, adhesion and invasion in MDA-MB-231 cells. In addition, we investigated the molecular mechanism by which cPLA(2)γ regulated migration. Knockdown of cPLA(2)γ suppressed the phosphorylation of Akt at both Thr308 and Ser473. Phosphorylation of PKCζ, downstream of Akt, was also dampened. Knockdown of cPLA(2)γ also impaired the phosphorylation of integrin β1 and cofilin, key regulators of cell adhesion and actin polymerization, respectively. Taken together, our results suggest that cPLA(2)γ plays an important role in cancer cell chemotaxis.
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Affiliation(s)
- Gang Tian
- Tianjin Medical University, Cancer Institute and Hospital, Tianjin 300060, China
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17
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Affiliation(s)
- Motonao Nakamura
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Hongo, Tokyo, Japan.
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18
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Parhamifar L, Sime W, Yudina Y, Vilhardt F, Mörgelin M, Sjölander A. Ligand-induced tyrosine phosphorylation of cysteinyl leukotriene receptor 1 triggers internalization and signaling in intestinal epithelial cells. PLoS One 2010; 5:e14439. [PMID: 21203429 PMCID: PMC3010979 DOI: 10.1371/journal.pone.0014439] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Accepted: 11/30/2010] [Indexed: 12/17/2022] Open
Abstract
Background Leukotriene D4 (LTD4) belongs to the bioactive lipid group known as eicosanoids and has implications in pathological processes such as inflammation and cancer. Leukotriene D4 exerts its effects mainly through two different G-protein-coupled receptors, CysLT1 and CysLT2. The high affinity LTD4 receptor CysLT1R exhibits tumor-promoting properties by triggering cell proliferation, survival, and migration in intestinal epithelial cells. In addition, increased expression and nuclear localization of CysLT1R correlates with a poorer prognosis for patients with colon cancer. Methodology/Principal Findings Using a proximity ligation assay and immunoprecipitation, this study showed that endogenous CysLT1R formed heterodimers with its counter-receptor CysLT2R under basal conditions and that LTD4 triggers reduced dimerization of CysLTRs in intestinal epithelial cells. This effect was dependent upon a parallel LTD4-induced increase in CysLT1R tyrosine phosphorylation. Leukotriene D4 also led to elevated internalization of CysLT1Rs from the plasma membrane and a simultaneous increase at the nucleus. Using sucrose, a clathrin endocytic inhibitor, dominant-negative constructs, and siRNA against arrestin-3, we suggest that a clathrin-, arrestin-3, and Rab-5-dependent process mediated the internalization of CysLT1R. Altering the CysLT1R internalization process at either the clathrin or the arrestin-3 stage led to disruption of LTD4-induced Erk1/2 activation and up-regulation of COX-2 mRNA levels. Conclusions/Significance Our data suggests that upon ligand activation, CysLT1R is tyrosine-phosphorylated and released from heterodimers with CysLT2R and, subsequently, internalizes from the plasma membrane to the nuclear membrane in a clathrin-, arrestin-3-, and Rab-5-dependent manner, thus, enabling Erk1/2 signaling and downstream transcription of the COX-2 gene.
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Affiliation(s)
- Ladan Parhamifar
- Cell and Experimental Pathology, Department of Laboratory Medicine, Clinical Research Center, Lund University, Skåne University Hospital, Malmö, Sweden
| | - Wondossen Sime
- Cell and Experimental Pathology, Department of Laboratory Medicine, Clinical Research Center, Lund University, Skåne University Hospital, Malmö, Sweden
| | - Yuliana Yudina
- Cell and Experimental Pathology, Department of Laboratory Medicine, Clinical Research Center, Lund University, Skåne University Hospital, Malmö, Sweden
| | - Frederik Vilhardt
- Institute of Cellular and Molecular Medicine, Panum Institute, Copenhagen University, Copenhagen, Denmark
| | - Matthias Mörgelin
- Infectious Medicine, Department of Clinical Science, Lund University, Lund, Sweden
| | - Anita Sjölander
- Cell and Experimental Pathology, Department of Laboratory Medicine, Clinical Research Center, Lund University, Skåne University Hospital, Malmö, Sweden
- * E-mail:
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19
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Montreekachon P, Chotjumlong P, Reutrakul V, Krisanaprakornkit S. Involvement of Cytosolic Phospholipase A2α in MMP-9 Up-regulation. J Dent Res 2009; 88:1031-6. [DOI: 10.1177/0022034509345967] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Matrix metalloproteinase-9 (MMP-9) is important in the pathogenesis of periodontitis. Cytosolic phospholipase A2α (cPLA2α) is involved in MMP-9 up-regulation in human monocytes. We tested the hypothesis that cPLA2α also regulates MMP-9 induction by Fusobacterium nucleatum and by phorbol 12-myristate-13-acetate (PMA) in gingival epithelial cells. While PMA induced MMP-9 expression considerably, F. nucleatum did so moderately. This time-course study demonstrated that MMP-9 mRNA up-regulation occurred at 3 hours, whereas MMP-9 secretion and activity in cell-free supernatants occurred at 12 hours. cPLA2α mRNA was constitutively expressed in gingival epithelial cells. Transient activation of cPLA2 by Ser505 phosphorylation was observed in the nuclei upon stimulation, suggesting its role as a transcription factor, while cPLA2 protein expression remained unchanged. Induction of MMP-9 expression and activity was significantly inhibited by 1 μM of the specific cPLA2α inhibitor (P < 0.01). These findings demonstrate the involvement of cPLA2α in MMP-9 up-regulation.
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Affiliation(s)
- P. Montreekachon
- Center of Excellence for Innovation in Chemistry, Department of
Odontology and Oral Pathology, Faculty of Dentistry, Chiang Mai University, Chiang
Mai 50200, Thailand; and
- Department of Chemistry and Center of Excellence for Innovation in
Chemistry, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - P. Chotjumlong
- Center of Excellence for Innovation in Chemistry, Department of
Odontology and Oral Pathology, Faculty of Dentistry, Chiang Mai University, Chiang
Mai 50200, Thailand; and
- Department of Chemistry and Center of Excellence for Innovation in
Chemistry, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - V. Reutrakul
- Center of Excellence for Innovation in Chemistry, Department of
Odontology and Oral Pathology, Faculty of Dentistry, Chiang Mai University, Chiang
Mai 50200, Thailand; and
- Department of Chemistry and Center of Excellence for Innovation in
Chemistry, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - S. Krisanaprakornkit
- Center of Excellence for Innovation in Chemistry, Department of
Odontology and Oral Pathology, Faculty of Dentistry, Chiang Mai University, Chiang
Mai 50200, Thailand; and
- Department of Chemistry and Center of Excellence for Innovation in
Chemistry, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
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20
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Li C, Li X, Miao Y, Wang Q, Jiang W, Xu C, Li J, Han J, Zhang F, Gong B, Xu L. SubpathwayMiner: a software package for flexible identification of pathways. Nucleic Acids Res 2009; 37:e131. [PMID: 19706733 PMCID: PMC2770656 DOI: 10.1093/nar/gkp667] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
With the development of high-throughput experimental techniques such as microarray, mass spectrometry and large-scale mutagenesis, there is an increasing need to automatically annotate gene sets and identify the involved pathways. Although many pathway analysis tools are developed, new tools are still needed to meet the requirements for flexible or advanced analysis purpose. Here, we developed an R-based software package (SubpathwayMiner) for flexible pathway identification. SubpathwayMiner facilitates sub-pathway identification of metabolic pathways by using pathway structure information. Additionally, SubpathwayMiner also provides more flexibility in annotating gene sets and identifying the involved pathways (entire pathways and sub-pathways): (i) SubpathwayMiner is able to provide the most up-to-date pathway analysis results for users; (ii) SubpathwayMiner supports multiple species (∼100 eukaryotes, 714 bacteria and 52 Archaea) and different gene identifiers (Entrez Gene IDs, NCBI-gi IDs, UniProt IDs, PDB IDs, etc.) in the KEGG GENE database; (iii) the system is quite efficient in cooperating with other R-based tools in biology. SubpathwayMiner is freely available at http://cran.r-project.org/web/packages/SubpathwayMiner/.
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Affiliation(s)
- Chunquan Li
- College of Bioinformatics Science and Technology and Bio-pharmaceutical Key Laboratory of Heilongjiang Province, Harbin Medical University, Harbin 150081, People's Republic of China
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21
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Nakano T, Inoue I, Shinozaki R, Matsui M, Akatsuka T, Takahashi S, Tanaka K, Akita M, Seo M, Hokari S, Katayama S, Komoda T. A possible role of lysophospholipids produced by calcium-independent phospholipase A(2) in membrane-raft budding and fission. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1788:2222-8. [PMID: 19643079 DOI: 10.1016/j.bbamem.2009.07.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2009] [Revised: 07/10/2009] [Accepted: 07/20/2009] [Indexed: 10/20/2022]
Abstract
Phospholipase A(2) (PLA(2)) not only plays a role in the membrane vesiculation system but also mediates membrane-raft budding and fission in artificial giant liposomes. This study aimed to demonstrate the same effects in living cells. Differentiated Caco-2 cells were cultured on filter membranes. MDCK cells were challenged with Influenza virus. The MDCK cultures were harvested for virus titration with a plaque assay. Alkaline phosphatase (ALP), a membrane-raft associated glycosylphosphatidylinositol (GPI)-anchored protein, was 70% released by adding 0.2 mmol/l lysophosphatidylcholine, which was abolished by treatment with a membrane-raft disrupter, methyl-beta-cyclodextrin. Activation of calcium-independent PLA(2) (iPLA(2)) by brefeldin A increased the apical release of ALP by approximately 1.5-fold (p<0.01), which was blocked by PLA(2) inhibitor bromoenol lactone (BEL). BEL also reduced Influenza virus production into the media (<10%) in the MDCK culture. These results suggest that cells utilize inverted corn-shaped lysophospholipids generated by PLA(2) to modulate plasma membrane structure and assist the budding of raft-associated plasma membrane particles, which virus utilizes for its budding. Brush borders are enriched with membrane-rafts and undergo rapid turnover; thus, PLA(2) may be involved in the regulatory mechanism in membrane dynamism. Further, iPLA(2) may provide a therapeutic target for viral infections.
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Affiliation(s)
- Takanari Nakano
- Department of Biochemistry, Faculty of Medicine, Saitama Medical University, Saitama 350-0455, Japan.
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22
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Increased production of the ether-lipid platelet-activating factor in intestinal epithelial cells infected by Salmonella enteritidis. Biochim Biophys Acta Mol Cell Biol Lipids 2008; 1781:270-6. [DOI: 10.1016/j.bbalip.2008.03.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2007] [Revised: 03/11/2008] [Accepted: 03/19/2008] [Indexed: 01/09/2023]
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23
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Taylor JT, Huang L, Pottle JE, Liu K, Yang Y, Zeng X, Keyser BM, Agrawal KC, Hansen JB, Li M. Selective blockade of T-type Ca2+ channels suppresses human breast cancer cell proliferation. Cancer Lett 2008; 267:116-24. [PMID: 18455293 DOI: 10.1016/j.canlet.2008.03.032] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2007] [Revised: 03/04/2008] [Accepted: 03/10/2008] [Indexed: 12/14/2022]
Abstract
We have measured the expression of T-type Ca2+ channel mRNA in breast cancer cell lines (MCF-7 (ERalpha+) using Western blot and quantitative real-time PCR (Q-RT-PCR). These results revealed that the MCF-7 cells express both alpha1G and alpha1H isoforms of T-type Ca2+ channels. In order to further clarify the role of T-type Ca2+ channels in proliferation, we tested the effects of a selective T-type Ca2+ channel inhibitor NNC-55-0396 on cellular proliferation. MCF-7 (ERalpha+) cellular proliferation was inhibited by the compound. In contrast, NNC-55-0396 at same concentration had no effect on the proliferation of MCF-10A cells, a non-cancer breast epithelial cell line. We also found that message expression of the T-type Ca2+ channels were only expressed in rapidly growing non-confluent cells but not in the cytostatic confluent cells. Knocking down the expression of T-type Ca2+ channels with siRNA targeting both alpha1G and alpha1H resulted in growth inhibition as much as 45%+/-5.0 in MCF-7 cells as compared to controls. In conclusion, our results suggest that T-type Ca2+ channel antagonism/silencing may reduce cellular proliferation in mitogenic breast cells.
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Affiliation(s)
- James T Taylor
- Department of Pharmacology, Tulane University Health Sciences Center, New Orleans, LA 70112, USA
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24
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Wooten RE, Willingham MC, Daniel LW, Leslie CC, Rogers LC, Sergeant S, O'Flaherty JT. Novel translocation responses of cytosolic phospholipase A2alpha fluorescent proteins. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1783:1544-50. [PMID: 18406359 DOI: 10.1016/j.bbamcr.2008.03.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 03/04/2008] [Accepted: 03/05/2008] [Indexed: 12/13/2022]
Abstract
Cytosolic phospholipase A2 (cPLA2)alpha responds to the rise in cytosolic Ca2+ ([Ca2+]i) attending cell stimulation by moving to intracellular membranes, releasing arachidonic acid (AA) from these membranes, and thereby initiating the synthesis of various lipid mediators. Under some conditions, however, cPLA2alpha translocation occurs without any corresponding changes in [Ca2+]i. The signal for such responses has not been identified. Using confocal microscopy to track fluorescent proteins fused to cPLA2alpha or cPLA2alpha's C2 domain, we find that AA mimics Ca2+ ionophores in stimulating cPLA(2)alpha translocations to the perinuclear ER and to a novel site, the lipid body. Unlike the ionophores, AA acted independently of [Ca2+](i) rises and did not translocate the proteins to the Golgi. AA's action did not involve its metabolism to eicosanoids or acylation into cellular lipids. Receptor agonists also stimulated translocations targeting lipid bodies. We propose that AA is a signal for Ca2+-independent cPLA2alpha translocation and that lipid bodies are common targets of cPLA2alpha and contributors to stimulus-induced lipid mediator synthesis.
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Affiliation(s)
- Rhonda E Wooten
- Department of Internal Medicine, Section on Infectious Diseases, Wake Forest University Health Sciences, Medical Center Boulevard, Winston-Salem, NC 27157, USA
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25
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Ehrnström RA, Bjursten LM, Ljungberg O, Veress B, Haglund ME, Lindström CG, Andersson T. Dietary supplementation with carbonate increases expression of ornithine decarboxylase and proliferation in gastric mucosa in a rat model of gastric cancer. Int J Cancer 2008; 122:727-33. [PMID: 17960625 DOI: 10.1002/ijc.23151] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Dietary factors play essential roles in gastric carcinogenesis. We recently found that dietary supplementation with NaHCO(3) significantly increased the development of gastric cancer in a rat gastric stump model. Here, we analysed nontransformed gastric mucosa for expression of the cancer-related proteins cyclooxygenase-2 (COX-2) and ornithine decarboxylase (ODC), and we examined the relationship between expression levels of those proteins and mucosal proliferation. Research has shown that COX-2 is upregulated in gastric mucosal inflammation and is strongly associated with gastrointestinal cancer. ODC is the key enzyme in polyamine synthesis and a regulator of cell proliferation. We performed gastric resections on 48 Wistar rats to induce spontaneous gastric cancer; half of these animals were given a normal diet, and the other half received a diet supplemented with NaHCO(3). Twenty-four unoperated rats served as a control group. The surgical procedure per se led to a significant rise in mucosal expression of COX-2 and an associated increase in cell proliferation. However, the COX-2 level in gastric mucosa was not further affected by dietary supplementation of carbonate. Interestingly, nontransformed gastric mucosa in the operated rats receiving a carbonate-supplemented diet showed a pronounced increase in ODC expression that was strongly correlated with a further enhanced cell proliferation. These results indicate that carbonate ions, which represent a major constituent of intestinal reflux into the stomach, increase the expression of ODC and thereby enhance cell proliferation in nontransformed mucosa, and consequently elevate the risk of gastric cancer.
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Affiliation(s)
- Roy A Ehrnström
- Division of Pathology, Department of Laboratory Medicine of Lund University, Malmö University Hospital, Malmö, Sweden.
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26
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Magnusson C, Ehrnström R, Olsen J, Sjölander A. An increased expression of cysteinyl leukotriene 2 receptor in colorectal adenocarcinomas correlates with high differentiation. Cancer Res 2007; 67:9190-8. [PMID: 17909024 DOI: 10.1158/0008-5472.can-07-0771] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Increased levels of inflammatory mediators such as cysteinyl leukotrienes (CysLT) have been found in and around tumors. These data, along with our previous observation that the G-protein-coupled receptor CysLT(1)R, which signals survival and proliferation, is up-regulated in colon cancer, suggest an important role for CysLT(1)R in tumor development. The objective of this study was to examine the expression and function of the low-affinity CysLT2 receptor (CysLT2R) in colon cancer. We found lower expression levels of CysLT2R compared with CysLT(1)R in cancer cell lines as well as clinical tumor material. Interestingly, CysLT2R, like CysLT(1)R, was found to be one of few G-protein-coupled receptors that are located both at the plasma membrane and the nuclear membrane. No effect of CysLT2R signaling on cell proliferation was observed, nor was there a correlation between CysLT2R and different proliferation markers such as Ki-67 and cyclooxygenase-2 in the tumor material. Instead, we found that activation of this receptor in colon cancer cells led to cellular differentiation similar to the effects of butyrate treatment. In accordance with this finding, we found that reduced expression of CysLT2R in colon cancer was associated with poor prognosis. We report the novel finding that CysLT2R signaling leads to terminal differentiation of colon carcinoma cells and growth inhibition, and that its expression is relatively high in less malignant forms of colon cancer. These data suggest that the balance between these two receptors is important for tumor progression and disease outcome.
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Affiliation(s)
- Cecilia Magnusson
- Division of Cell and Experimental Pathology, Lund University, Malmö University Hospital, Malmö, Sweden
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27
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Di Mari JF, Saada JI, Mifflin RC, Valentich JD, Powell DW. HETEs enhance IL-1-mediated COX-2 expression via augmentation of message stability in human colonic myofibroblasts. Am J Physiol Gastrointest Liver Physiol 2007; 293:G719-28. [PMID: 17640979 DOI: 10.1152/ajpgi.00117.2007] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Proinflammatory cytokines and eicosanoids are central players in intestinal inflammation. IL-1, a key cytokine associated with intestinal mucosal inflammation, induces COX-2 expression in human colonic myofibroblasts (CMF) and increased prostaglandin E(2) secretion is associated with inflammatory bowel disease (IBD) and colorectal cancer (CRC). We have previously demonstrated that IL-1alpha-induced cyclooxygenase-2 (COX-2) expression is the result of NF-kappaB- and ERK-mediated transcription, as well as COX-2 message stabilization, which depends on p38, MAPKAPK-2 (MK-2) and human antigen R (HuR) RNA binding protein activation. Lipoxygenase (LOX)-derived hydroxyeicosatetraenoic acids (HETEs) are elevated in IBD and colonic adenomas and "cross talk" has been observed between the COX and LOX pathways. Since COX-2 expression is primarily in CMFs in colonic adenomas, we examined the impact of LOX metabolites, particularly HETEs, on IL-1alpha-induced COX-2 expression in human CMFs. Although 5(S)-, 12(R)-, and 15(S)-HETEs alone had little to no effect on COX-2 expression, they enhanced IL-1-mediated COX-2 expression 3.6 +/- 0.5-fold. Studies utilizing heterogeneous nuclear RNA amplification and 5,6-dichloro-beta-d-ribofuranosylbenzimidazole treatment were undertaken to measure COX-2 transcription and message stabilization, respectively. We found that HETEs enhanced IL-1-induced COX-2 mRNA levels in CMF as the result of increased p38, MK-2, and HuR activity, increasing message stability greater than that observed with IL-1 alone. Thus HETEs can act synergistically with IL-1alpha to induce COX-2 expression in human CMFs. HETEs may play a role in both colonic inflammation and in increasing the risk of CRC in IBD independently and via induction of COX-2-mediated prostaglandin secretion.
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Affiliation(s)
- J F Di Mari
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA.
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Capra V, Thompson MD, Sala A, Cole DE, Folco G, Rovati GE. Cysteinyl-leukotrienes and their receptors in asthma and other inflammatory diseases: critical update and emerging trends. Med Res Rev 2007; 27:469-527. [PMID: 16894531 DOI: 10.1002/med.20071] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Cysteinyl-leukotrienes (cysteinyl-LTs), that is, LTC4, LTD4, and LTE4, trigger contractile and inflammatory responses through the specific interaction with G protein-coupled receptors (GPCRs) belonging to the purine receptor cluster of the rhodopsin family, and identified as CysLT receptors (CysLTRs). Cysteinyl-LTs have a clear role in pathophysiological conditions such as asthma and allergic rhinitis (AR), and have been implicated in other inflammatory conditions including cardiovascular diseases, cancer, atopic dermatitis, and urticaria. Molecular cloning of human CysLT1R and CysLT2R subtypes has confirmed most of the previous pharmacological characterization and identified distinct expression patterns only partially overlapping. Interestingly, recent data provide evidence for the immunomodulation of CysLTR expression, the existence of additional receptor subtypes, and of an intracellular pool of CysLTRs that may have roles different from those of plasma membrane receptors. Furthermore, genetic variants have been identified for the CysLTRs that may interact to confer risk for atopy. Finally, a crosstalk between the cysteinyl-LT and the purine systems is being delineated. This review will summarize and attempt to integrate recent data derived from studies on the molecular pharmacology and pharmacogenetics of CysLTRs, and will consider the therapeutic opportunities arising from the new roles suggested for cysteinyl-LTs and their receptors.
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MESH Headings
- Adult
- Animals
- Asthma/drug therapy
- Asthma/physiopathology
- Cardiovascular Diseases/physiopathology
- Child
- Child, Preschool
- Dermatitis, Atopic/drug therapy
- Dermatitis, Atopic/etiology
- Female
- Humans
- Hydroxyurea/adverse effects
- Hydroxyurea/analogs & derivatives
- Leukotriene Antagonists/adverse effects
- Leukotriene Antagonists/therapeutic use
- Leukotriene C4/physiology
- Leukotriene D4/physiology
- Leukotriene E4/physiology
- Membrane Proteins/drug effects
- Membrane Proteins/genetics
- Membrane Proteins/physiology
- Pharmacogenetics
- Receptors, Leukotriene/drug effects
- Receptors, Leukotriene/genetics
- Receptors, Leukotriene/physiology
- Receptors, Purinergic/physiology
- Recombinant Proteins/pharmacology
- Rhinitis, Allergic, Seasonal/drug therapy
- Rhinitis, Allergic, Seasonal/physiopathology
- SRS-A/biosynthesis
- Tissue Distribution
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Affiliation(s)
- Valérie Capra
- Department of Pharmacological Sciences, University of Milan, Via Balzaretti 9, 20133 Milan, Italy.
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Welman A, Cawthorne C, Ponce-Perez L, Barraclough J, Danson S, Murray S, Cummings J, Allen TD, Dive C. Increases in c-Src expression level and activity do not promote the growth of human colorectal carcinoma cells in vitro and in vivo. Neoplasia 2007; 8:905-16. [PMID: 17132222 PMCID: PMC1716016 DOI: 10.1593/neo.06475] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The levels and activity of c-Src in colorectal cancer cells increase steadily during the course of colorectal carcinogenesis and are most highly elevated in advanced metastatic disease. However, the effects of increases in c-Src activity on the proliferation of colorectal cancer cells during early and late stages of tumorigenesis remain elusive. To study the consequences of increases in c-Src levels and activity on the growth of colorectal cancer cells in later stages of colorectal carcinogenesis, we developed human colorectal cancer cell lines in which c-Src levels and activity could be inducibly increased by a tightly controlled expression of wild-type c-Src or of the constitutively active mutant of c-Src, c-SrcY527F. Src induction activated multiple signaling pathways (often associated with a proliferative response) but promoted neither cell proliferation in vitro nor tumor growth in a xenograft model in vivo. These results indicate that, in more advanced stages of colorectal carcinogenesis, increases in c-Src levels and activity are likely to have functions other than the direct promotion of tumor growth.
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Affiliation(s)
- Arkadiusz Welman
- Clinical and Experimental Pharmacology Group, Cancer Research UK, Paterson Institute for Cancer Research, University of Manchester, Wilmslow Road, Manchester M20 4BX, UK.
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30
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Broom OJ, Massoumi R, Sjölander A. Alpha2beta1 integrin signalling enhances cyclooxygenase-2 expression in intestinal epithelial cells. J Cell Physiol 2006; 209:950-8. [PMID: 16972245 DOI: 10.1002/jcp.20796] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Inflammatory bowel diseases (IBD) are linked to an increased risk of developing colon cancer, by inflammatory mediators and alterations to the extracellular matrix (ECM). The events induced by inflammatory mediators lead to dysregulated activation and induction of inflammatory genes such as cyclooxygenase-2 (COX-2). COX-2 is involved in the conversion of arachidonic acid to biologically active prostanoids and is highly upregulated in colon cancer. Since inflammation-induced changes to the extracellular matrix could affect integrin activities, we here investigated the effect of integrin signalling on the level of COX-2 expression in the non-transformed intestinal epithelial cell lines, Int 407 and IEC-6. Adhesion of these cells to a collagen I- or IV-coated surface, increased surface expression of alpha2beta1 integrin. Activation of integrins with collagen caused an increased cox-2 promoter activity, with a subsequent increase in COX-2 expression. The signalling cascade leading to this increased expression and promoter activity of cox-2, involves PKCalpha, the small GTPase Ras and NFkappaB but not Erk1/2 or Src activity. The integrin-induced increase in cellular COX-2 activity is responsible for an elevated generation of reactive oxygen species (ROS) and increased cell migration. This signalling pathway suggests a mechanism whereby inflammation-induced modulations of the ECM, can promote cancer transformation in the intestinal epithelial cells.
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Affiliation(s)
- Oliver Jay Broom
- Cell and Experimental Pathology, Department of Laboratory Medicine, Lund University, Malmö University Hospital, SE-205 02 Malmö, Sweden
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Wang Q, Zhou Y, Evers BM. Neurotensin phosphorylates GSK-3alpha/beta through the activation of PKC in human colon cancer cells. Neoplasia 2006; 8:781-7. [PMID: 16984735 PMCID: PMC1584301 DOI: 10.1593/neo.06259] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Neurotensin (NT), a gastrointestinal hormone, binds its receptor [neurotensin receptor (NTR)] to regulate the growth of normal and neoplastic intestinal cells; molecular mechanisms remain largely undefined. Glycogen synthase kinase-3 (GSK-3) regulates diverse cellular processes, including cell growth and apoptosis. Here, we show that NT induces the phosphorylation of GSK-3alpha/beta in the human colon cancer cell line HT29, HCT116, or SW480, which possesses high-affinity NTR. The effect of NT was blocked by inhibitors of protein kinase C (PKC), but not by inhibitors of MEK1 or phosphatidylinositol-3 kinase, suggesting a predominant role for PKC in GSK-3beta phosphorylation by NT. Pretreatment with Gö6976 (which inhibits PKCalpha and PKCbeta1) or downregulation of endogenous PKCalpha or PKCbeta1 blocked NT-mediated GSK-3beta (but not GSK-3alpha) phosphorylation. Moreover, a selective PKCbeta inhibitor, LY379196, reduced NT-mediated GSK-3beta (but not GSK-3alpha) phosphorylation, suggesting a role for PKCbeta1 in the NT-mediated phosphorylation of GSK-3beta and an undefined kinase in the NT-mediated phosphorylation of GSK-3alpha. Treatment with NT or the GSK-3 inhibitor SB216763 increased the expression of cyclin D1, a downstream effector protein of GSK-3 and a critical protein for the proliferation of various cells. Our results indicate that NT uses PKC-dependent pathways to modulate GSK-3, which may play a role in the NT regulation of intestinal cell growth.
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Affiliation(s)
- Qingding Wang
- Department of Surgery, The University of Texas Medical Branch, Galveston, TX, USA
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Yedgar S, Cohen Y, Shoseyov D. Control of phospholipase A2 activities for the treatment of inflammatory conditions. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1761:1373-82. [PMID: 16978919 DOI: 10.1016/j.bbalip.2006.08.003] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2006] [Accepted: 08/01/2006] [Indexed: 01/10/2023]
Abstract
Phospholipase-A2 (PLA2) enzymes hydrolyze cell membrane phospholipids to produce arachidonic acid (AA) and lyso-phospholipids (LysoPL), playing a key role in the production of inflammatory lipid mediators, mainly eicosanoids. They are therefore considered pro-inflammatory enzymes and their inhibition has long been recognized as a desirable therapeutic target. However, attempts to develop suitable PLA2 inhibitors for the treatment of inflammatory diseases have yet to succeed. This is due to their functional and structural diversity, and their homeostatic and even anti-inflammatory roles in certain circumstances. In the present review we outline the diversity and functions of PLA2 isoforms, and their interplay in the induction and inhibition of inflammatory processes, with emphasis on discussing approaches for therapeutic manipulation of PLA2 activities.
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Affiliation(s)
- Saul Yedgar
- Department of Biochemistry, Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel.
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Shi Y, Cui L, Dai G, Chen J, Pan H, Song L, Cheng S, Wang X. Elevated prostaglandin E2 level via cPLA2--COX-2--mPGES-1 pathway involved in bladder carcinogenesis induced by terephthalic acid-calculi in Wistar rats. Prostaglandins Leukot Essent Fatty Acids 2006; 74:309-15. [PMID: 16621493 DOI: 10.1016/j.plefa.2006.02.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Accepted: 02/28/2006] [Indexed: 11/29/2022]
Abstract
To investigate the prostaglandin E2 (PGE2) biosynthetic mechanism in bladder carcinogenesis, we established Wistar rat model of bladder papilloma and transitional cell carcinoma (TCC) induced by 5% terephthalic acid (TPA) treatment. Then, the mRNA level of cytosolic phospholipase A2 (cPLA2), cyclooxygenases (COX)-1 and -2, membrane-bound PGE2 synthases (mPGES)-1 and -2 was detected using reverse transcription polymerase chain reaction (RT-PCR). Immunoblotting was applied to detect the expression of COX-2 protein. Proliferating cell nuclear antigen (PCNA) was determined by immunohistochemistry. In addition, the level of PGE2 was measured by radioimmunoassay (RIA). Bladder papilloma (100%, 8/8) was examined in rats after 24-week treatment, and bladder TCC (80%, 16/20) was found after 48-week treatment. Histopathological changes were not found in control group rats. The incidence of bladder papilloma and TCC in test group was significantly higher than that in control group (P<0.01). The mRNA levels of cPLA2, COX-2 and mPGES-1 in the bladder papilloma and TCC were significantly higher than those in normal bladder (P<0.01), while the mRNA levels of COX-1 and mPGES-2 in TCC were unchanged compared with normal bladder. Bladder TCC exhibited a substantial expression of COX-2 protein. On the contrary, normal bladder tissue barely expresses COX-2 protein. PCNA labeling index (LI) and the level of PGE2 in bladder papilloma are much higher than those in normal bladder (P<0.01), but lower than those in bladder TCC (P<0.05). In conclusion, increasing PGE2 level via cPLA2--COX-2--mPGES-1 pathway may play an important role in rat bladder carcinogenesis. PGE2 may be a biomarker for the development of bladder TCC. cPLA2 and mPGES-1 may be targets for development of novel chemoprevention strategies for bladder TCC.
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Affiliation(s)
- Yuan Shi
- Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 210029, China
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