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PLA2G2A Phospholipase Promotes Fatty Acid Synthesis and Energy Metabolism in Pancreatic Cancer Cells with K-ras Mutation. Int J Mol Sci 2022; 23:ijms231911721. [PMID: 36233022 PMCID: PMC9570406 DOI: 10.3390/ijms231911721] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 09/22/2022] [Accepted: 09/23/2022] [Indexed: 01/17/2023] Open
Abstract
Oncogenic K-ras is often activated in pancreatic ductal adenocarcinoma (PDAC) due to frequent mutation (>90%), which drives multiple cellular processes, including alterations in lipid metabolism associated with a malignant phenotype. However, the role and mechanism of the altered lipid metabolism in K-ras-driven cancer remains poorly understood. In this study, using human pancreatic epithelial cells harboring inducible K-rasG12D (HPNE/K-rasG12D) and pancreatic cancer cell lines, we found that the expression of phospholipase A2 group IIA (PLA2G2A) was upregulated by oncogenic K-ras. The elevated expression of PLA2G2A was also observed in pancreatic cancer tissues and was correlated with poor survival of PDAC patients. Abrogation of PLA2G2A by siRNA or by pharmacological inhibition using tanshinone I significantly increased lipid peroxidation, reduced fatty acid synthase (FASN) expression, and impaired mitochondrial function manifested by a decrease in mitochondrial transmembrane potential and a reduction in ATP production, leading to the inhibition of cancer cell proliferation. Our study suggests that high expression of PLA2G2A induced by oncogenic K-ras promotes cancer cell survival, likely by reducing lipid peroxidation through its ability to facilitate the removal of polyunsaturated fatty acids from lipid membranes by enhancing the de novo fatty acid synthesis and energy metabolism to support cancer cell proliferation. As such, PLA2G2A might function as a downstream mediator of K-ras and could be a potential therapeutic target.
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Wu W, Li WX, Huang CH. Phospholipase A 2, a nonnegligible enzyme superfamily in gastrointestinal diseases. Biochimie 2021; 194:79-95. [PMID: 34974145 DOI: 10.1016/j.biochi.2021.12.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 12/25/2021] [Accepted: 12/28/2021] [Indexed: 11/16/2022]
Abstract
Gastrointestinal tract is important for digestion, absorption, detoxification and immunity. Gastrointestinal diseases are mainly caused by the imbalance of protective and attacking factors in gastrointestinal mucosa, which can seriously harm human health. Phospholipase A2 (PLA2) is a large family closely involved in lipid metabolism and is found in almost all human cells. A growing number of studies have revealed that its metabolites are deeply implicated in various inflammatory pathways and also regulates the maintenance of numerous biological events such as dietary digestion, membrane remodeling, barrier action, and host immunity. In addition to their phospholipase activity, some members of the superfamily also have other catalytic activities. Based on the in-depth effects of phospholipase A2 on bioactive lipid metabolism and inflammatory cytokines, PLA2 and its metabolites are likely to be involved in the pathogenesis, development or prevention of gastrointestinal diseases. Therefore, this review will focus on the physiological and pathogenic roles of several important PLA2 enzymes in the gastrointestinal tract, and reveals the potential of PLA2 as a therapeutic target for gastrointestinal diseases.
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Affiliation(s)
- Wei Wu
- Queen Mary School, Medical Department, Nanchang University, Nanchang, Jiangxi, China
| | - Wen-Xuan Li
- Queen Mary School, Medical Department, Nanchang University, Nanchang, Jiangxi, China
| | - Chun-Hong Huang
- School of Basic Medical Sciences, 330006, Nanchang University, Nanchang, Jiangxi, China.
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Zhang Y, Dong S, Xu R, Yang Y, Zheng Z, Wang X, Ren R, Sun R, Li M, Yang H, Huang Y, Zhou F, Zheng A. Prognostic and predictive role of COX-2, XRCC1 and RASSF1 expression in patients with esophageal squamous cell carcinoma receiving radiotherapy. Oncol Lett 2017; 13:2549-2556. [PMID: 28454432 PMCID: PMC5403488 DOI: 10.3892/ol.2017.5780] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Accepted: 11/07/2016] [Indexed: 01/13/2023] Open
Abstract
Identification of biomarkers for predicting radiosensitivity would be useful for administering individualized radiotherapy (RT) to patients with esophageal cancer. The aim of the present study was to evaluate the association between cyclooxygenase-2 (COX-2), X-ray repair cross complementing group 1 (XRCC1), ras association domain family 1 (RASSF1) protein expression, clinicopathological characteristics, radiosensitivity and survival rate in 76 patients with esophageal squamous cell carcinoma (ESCC) who were treated with RT. Positive expression of COX-2, XRCC1 and RASSF1 was identified by immunohistochemistry in 81.6, 52.6 and 59.2% of ESCC cases, respectively. Negative COX-2 expression was associated with tumor (T) stage, node (N) stage, clinical stage and complete response (P<0.05), but not with gender, age, tumor location, differentiation degree, lesion length, progression-free survival (PFS) or overall survival (OS; P>0.05). XRCC1 expression was not associated with the clinicopathological features of ESCC, response to RT, PFS or OS. Positive RASSF1 expression was associated with the clinical stage, response to RT, PFS and OS (P<0.05), but not with gender, age, tumor location, T stage, N stage, differentiation degree or the lesion length (P>0.05). In the subgroup analysis, RASSF1 positive/XRCC1 negative expression was correlated with a longer median OS and PFS (P<0.05). Multivariate analyses revealed that the tumor response and RASSF1 expression were significant prognostic factors. Therefore, positive RASSF1 expression is associated with ESCC RT sensitivity, and may be a useful independent prognostic factor for ESCC.
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Affiliation(s)
- Yaowen Zhang
- Department of Radiation Oncology, Anyang Cancer Hospital, Anyang, Henan 455000, P.R. China
| | - Shangwen Dong
- Department of Cardiothoracic Surgery, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Ruiping Xu
- Department of Radiation Oncology, Anyang Cancer Hospital, Anyang, Henan 455000, P.R. China
| | - Yanping Yang
- Department of Radiation Oncology, Anyang Cancer Hospital, Anyang, Henan 455000, P.R. China
| | - Zhiyong Zheng
- Department of Radiation Oncology, Anyang Cancer Hospital, Anyang, Henan 455000, P.R. China
| | - Xiaojing Wang
- Department of Radiation Oncology, Anyang Cancer Hospital, Anyang, Henan 455000, P.R. China
| | - Runchuan Ren
- Department of Radiation Oncology, Anyang Cancer Hospital, Anyang, Henan 455000, P.R. China
| | - Ronggang Sun
- Department of Radiation Oncology, Anyang Cancer Hospital, Anyang, Henan 455000, P.R. China
| | - Ming Li
- Department of Radiation Oncology, Anyang Cancer Hospital, Anyang, Henan 455000, P.R. China
| | - Haijun Yang
- Department of Radiation Oncology, Anyang Cancer Hospital, Anyang, Henan 455000, P.R. China
| | - Yuting Huang
- Department of Gynecological Oncology, Tianjin Medical Univerisity Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin 300060, P.R. China
| | - Fuyou Zhou
- Department of Radiation Oncology, Anyang Cancer Hospital, Anyang, Henan 455000, P.R. China
| | - Anping Zheng
- Department of Radiation Oncology, Anyang Cancer Hospital, Anyang, Henan 455000, P.R. China
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