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Jiang Q, Miao J, Wu F, Li F, Zhang J, Jing X, Cai S, Ma X, Wang X, Zhao L, Huang C. RNF6 promotes gastric cancer progression by regulating CCNA1/CREBBP transcription. Cell Cycle 2023; 22:2018-2037. [PMID: 37904524 PMCID: PMC10761170 DOI: 10.1080/15384101.2023.2275899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 10/21/2023] [Indexed: 11/01/2023] Open
Abstract
Ring finger protein 6 (RNF6) is a member of the E3 ubiquitin ligase family. Previous studies have reported the involvement of RNF6 as a ubiquitin ligase in the progression of gastric cancer (GC). However, this study found that RNF6 has a clear localization in the nucleus of GC, indicating a role other than ubiquitin ligase. Further chromatin immunoprecipitation sequencing (ChIP-seq) analysis revealed that RNF6 has DNA binding and transcriptional regulatory effects and is involved in important pathways such as tumor cell cycle and apoptosis. Cyclin A1 (CCNA1) and CREB binding protein (CREBBP) are downstream targets for RNF6 transcription regulation in GC. RNF6 binds to the promoter region of CCNA1/CREBBP and is actively regulating their expression in GC cells. Silencing CCNA1/CREBBP partially reversed the promoting effect of RNF6 overexpression on the biological function of GC cells. Our study suggests that RNF6 promotes the progression of GC by regulating CCNA1/CREBBP transcription.
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Affiliation(s)
- Qiuyu Jiang
- Department of Cell Biology and Genetics/Key Laboratory of Environment and Genes Related to Diseases, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, Shaanxi, China
| | - Jiyu Miao
- Department of Hematology, The Second Affiliated Hospital, Xi’an Jiaotong University, Xi’an, Shaanxi, China
| | - Fei Wu
- Department of Oncology, The Second Affiliated Hospital, Xi’an Jiaotong University, Xi’an, Shaanxi, China
| | - Fang Li
- Department of Cell Biology and Genetics/Key Laboratory of Environment and Genes Related to Diseases, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, Shaanxi, China
| | - Jinyuan Zhang
- Department of Cell Biology and Genetics/Key Laboratory of Environment and Genes Related to Diseases, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, Shaanxi, China
| | - Xintao Jing
- Department of Cell Biology and Genetics/Key Laboratory of Environment and Genes Related to Diseases, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, Shaanxi, China
| | - Shuang Cai
- Department of Cell Biology and Genetics/Key Laboratory of Environment and Genes Related to Diseases, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, Shaanxi, China
| | - Xiaoping Ma
- Department of Cell Biology and Genetics/Key Laboratory of Environment and Genes Related to Diseases, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, Shaanxi, China
| | - Xiaofei Wang
- Department of Cell Biology and Genetics/Key Laboratory of Environment and Genes Related to Diseases, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, Shaanxi, China
| | - Lingyu Zhao
- Department of Cell Biology and Genetics/Key Laboratory of Environment and Genes Related to Diseases, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, Shaanxi, China
| | - Chen Huang
- Department of Cell Biology and Genetics/Key Laboratory of Environment and Genes Related to Diseases, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, Shaanxi, China
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Zengin T, Önal-Süzek T. Analysis of genomic and transcriptomic variations as prognostic signature for lung adenocarcinoma. BMC Bioinformatics 2020; 21:368. [PMID: 32998690 PMCID: PMC7526001 DOI: 10.1186/s12859-020-03691-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Background Lung cancer is the leading cause of the largest number of deaths worldwide and lung adenocarcinoma is the most common form of lung cancer. In order to understand the molecular basis of lung adenocarcinoma, integrative analysis have been performed by using genomics, transcriptomics, epigenomics, proteomics and clinical data. Besides, molecular prognostic signatures have been generated for lung adenocarcinoma by using gene expression levels in tumor samples. However, we need signatures including different types of molecular data, even cohort or patient-based biomarkers which are the candidates of molecular targeting. Results We built an R pipeline to carry out an integrated meta-analysis of the genomic alterations including single-nucleotide variations and the copy number variations, transcriptomics variations through RNA-seq and clinical data of patients with lung adenocarcinoma in The Cancer Genome Atlas project. We integrated significant genes including single-nucleotide variations or the copy number variations, differentially expressed genes and those in active subnetworks to construct a prognosis signature. Cox proportional hazards model with Lasso penalty and LOOCV was used to identify best gene signature among different gene categories. We determined a 12-gene signature (BCHE, CCNA1, CYP24A1, DEPTOR, MASP2, MGLL, MYO1A, PODXL2, RAPGEF3, SGK2, TNNI2, ZBTB16) for prognostic risk prediction based on overall survival time of the patients with lung adenocarcinoma. The patients in both training and test data were clustered into high-risk and low-risk groups by using risk scores of the patients calculated based on selected gene signature. The overall survival probability of these risk groups was highly significantly different for both training and test datasets. Conclusions This 12-gene signature could predict the prognostic risk of the patients with lung adenocarcinoma in TCGA and they are potential predictors for the survival-based risk clustering of the patients with lung adenocarcinoma. These genes can be used to cluster patients based on molecular nature and the best candidates of drugs for the patient clusters can be proposed. These genes also have a high potential for targeted cancer therapy of patients with lung adenocarcinoma.
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Affiliation(s)
- Talip Zengin
- Department of Bioinformatics, Muğla Sıtkı Koçman University, Muğla, Turkey.,Department of Molecular Biology and Genetics, Muğla Sıtkı Koçman University, Muğla, Turkey
| | - Tuğba Önal-Süzek
- Department of Bioinformatics, Muğla Sıtkı Koçman University, Muğla, Turkey. .,Department of Computer Engineering, Muğla Sıtkı Koçman University, Muğla, Turkey.
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Yang Y, Li S, Cao J, Li Y, Hu H, Wu Z. RRM2 Regulated By LINC00667/miR-143-3p Signal Is Responsible For Non-Small Cell Lung Cancer Cell Progression. Onco Targets Ther 2019; 12:9927-9939. [PMID: 31819489 PMCID: PMC6876211 DOI: 10.2147/ott.s221339] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Accepted: 10/04/2019] [Indexed: 12/12/2022] Open
Abstract
Background Non-small cell lung cancer (NSCLC) is a common and fatal cancer worldwide with a very low 5-year overall survival rate. Ribonucleotide reductase M2 subunit (RRM2), a small subunit of the ribonucleotide reductase complex, has been found to be an oncogenic role in a variety of tumors including NSCLC. However, the regulatory mechanism of RRM2 in NSCLC is not clear. Increasing evidence suggests that non-coding RNAs (ncRNAs) including miRNAs and lincRNAs may promote or inhibit tumor initiation and development through regulating the expression of oncogenic genes. It is interesting to find ncRNAs which play important role in regulating RRM2 expression. Materials and methods The expression levels of RRM2, LINC0066 and miR-143-3p in NSCLC tumor tissues and cell lines were detected using qRT-PCR. The regulatory relationships among RRM2, LINC0066 and miR-143-3p were predicted using database analysis and verified by luciferase reporter assay and RIP analysis. The proliferation ability of NSCLC cells was assessed using CCK8 and colony formation assays. The expression of related proteins was determined by Western blot. In vivo effect of RRM2, LINC0066 and miR-143-3p to NSCLC were detected through xenograft experiments. Results In this study, we found RRM2 was upregulated in NSCLC tumor and cell lines, and the aberrant upregulation predicted a poor prognosis. Then, we predicted and confirmed that RRM2 was negatively regulated by miR-143-3p. Further study implied that LINC00667 acted as a ceRNA by sponging miR-143-3p and regulated RRM2 expression indirectly. Moreover, we found that the growth of NSCLC was regulated by LINC00667/miR-143-3p/RRM2 signal pathway both in vitro and in vivo. LINC00667 and RRM2 promoted the tumor growth while miR-143-3p inhibited it. Conclusion Our study revealed a LINC00667/miR-143-3p/RRM2 signal pathway that played an important role in the progress of NSCLC, which might be potential therapeutic targets for NSCLC.
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Affiliation(s)
- Yanbing Yang
- Department of Respiratory Medicine, Luohe Central Hospital, The First Affiliated Hospital of Luohe Medical College, Luohe, Henan 462000, People's Republic of China
| | - Sensen Li
- Department of Pharmacy, Luohe Central Hospital, The First Affiliated Hospital of Luohe Medical College, Luohe, Henan 462000, People's Republic of China
| | - Juan Cao
- Department of Respiratory Medicine, Luohe Central Hospital, The First Affiliated Hospital of Luohe Medical College, Luohe, Henan 462000, People's Republic of China
| | - Yaojun Li
- Department of Respiratory Medicine, Luohe Central Hospital, The First Affiliated Hospital of Luohe Medical College, Luohe, Henan 462000, People's Republic of China
| | - Haiying Hu
- Department of Respiratory Medicine, Luohe Central Hospital, The First Affiliated Hospital of Luohe Medical College, Luohe, Henan 462000, People's Republic of China
| | - Zhuyu Wu
- Department of Respiratory Medicine, Luohe Central Hospital, The First Affiliated Hospital of Luohe Medical College, Luohe, Henan 462000, People's Republic of China
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He X, Li S, Shi W, Lin Q, Ma J, Liu Y, Feng T, Cao X. Cyclin A1 is associated with poor prognosis in oesophageal squamous cell carcinoma. Oncol Lett 2019; 18:706-712. [PMID: 31289545 PMCID: PMC6546994 DOI: 10.3892/ol.2019.10377] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 04/02/2019] [Indexed: 12/19/2022] Open
Abstract
Dysregulation of cyclin A1 (CCNA1) is implicated in the carcinogenesis, progression and metastasis of many types of solid tumours. In the present study, an mRNA single-channel expression profile chip experiment revealed that the CCNA1 mRNA levels in oesophageal squamous cell carcinoma (ESCC) were increased >10-fold compared with those in the adjacent non-cancer tissues. Reverse transcription-quantitative polymerase chain reaction and immunohistochemistry analyses were performed to additionally investigate the role of CCNA1 in the development and progression of ESCC in patients treated by radical resection of the oesophagus. The association between CCNA1 mRNA expression and the clinicopathological parameters of patients with ESCC was statistically analysed. The results indicated that upregulation of CCNA1 occurred in ~70% of patients with ESCC, and increased CCNA1 mRNA expression was significantly associated with advanced clinical stage, lymph node metastasis, invasiveness and poor clinical outcome, including disease-free survival and overall survival rates. Taken together, the data suggested that CCNA1 had an important function in ESCC development and progression, and may serve as a prognostic biomarker and therapeutic target in ESCC.
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Affiliation(s)
- Xiaoting He
- Department of Surgical Oncology, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu 210000, P.R. China.,Department of Medical Oncology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, Jiangsu 214043, P.R. China
| | - Suqing Li
- Department of Surgical Oncology, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu 210000, P.R. China
| | - Weihong Shi
- Department of Clinical Medicine, Yancheng Vocational Institute of Health Sciences, Yancheng, Jiangsu 224005, P.R. China
| | - Qingfeng Lin
- Department of Medical Oncology, Jiangyin People's Hospital, Jiangyin, Jiangsu 214400, P.R. China
| | - Jian Ma
- Department of Surgical Oncology, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu 210000, P.R. China
| | - Yang Liu
- Department of Pharmacy, No. 401 Hospital of Chinese People's Liberation Army, Qingdao, Shandong 266071, P.R. China
| | - Tingting Feng
- Institute of Biology and Medical Sciences, Soochow University, Suzhou, Jiangsu 215123, P.R. China
| | - Xiufeng Cao
- Department of Surgical Oncology, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu 210000, P.R. China.,Department of Surgery, Nanjing Medical University, Taikang Xianlin Drum Tower Hospital, Jiangsu 210000, P.R. China
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5
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Ji T, Liu D, Shao W, Yang W, Wu H, Bian X. Decreased expression of LATS1 is correlated with the progression and prognosis of glioma. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2012; 31:67. [PMID: 22909338 PMCID: PMC3561646 DOI: 10.1186/1756-9966-31-67] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 08/07/2012] [Indexed: 12/21/2022]
Abstract
Background LATS1 is a tumor suppressor genes implicated in the pathogenesis of certain types of tumors, but its role is not known in human glioma. Methods Using real-time PCR and immunohistochemistry, we detected the mRNA and protein expression of LATS1 in glioma. The effect of LATS1 on cell growth and invasion were investigated. Results We found that mRNA and protein of LATS1 expression is significantly downregulated in glioma compared with normal control brain tissues. Furthermore, reduced LATS1 expression was markedly negatively correlated with WHO grade and KPS (p<0.001 and p<0.001) in glioma patients. Patients with lower LATS1 expression had a significantly shorter overall survival time than did patients with higher LATS1 expression. Multivariate analysis suggested that the level of LATS1 expression was an independent prognostic indicator (p<0.001) for the survival of patients with glioma. Forced expression of LATS1 in glioma U251 cells not only significantly suppressed cell growth, migration and invasion, but retarded cell cycle progression from G2/M to G1 in vitro. Finally, we found that overexpressed LATS1 markedly inhibited the expression level of cell cycle factor CCNA1. Conclusion These results indicate that LATS1 is an important candidate tumor suppressor and its downregulated expression may contribute to glioma progression.
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Affiliation(s)
- Tianhai Ji
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China
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Marlow LA, von Roemeling CA, Cooper SJ, Zhang Y, Rohl SD, Arora S, Gonzales IM, Azorsa DO, Reddi HV, Tun HW, Döppler HR, Storz P, Smallridge RC, Copland JA. Foxo3a drives proliferation in anaplastic thyroid carcinoma through transcriptional regulation of cyclin A1: a paradigm shift that impacts current therapeutic strategies. J Cell Sci 2012; 125:4253-63. [PMID: 22718346 DOI: 10.1242/jcs.097428] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The Forkhead transcription factor, FoxO3a, is a known suppressor of primary tumor growth through transcriptional regulation of key genes regulating cell cycle arrest and apoptosis. In many types of cancer, in response to growth factor signaling, FoxO3a is phosphorylated by Akt, resulting in its exclusion from the nucleus. Here we show that FoxO3a remains nuclear in anaplastic thyroid carcinoma (ATC). This correlates with lack of Akt phosphorylation at serine473 in ATC cell lines and tissues of ATC patients, providing a potential explanation for nuclear FoxO3a. Mechanistically, nuclear FoxO3a promotes cell cycle progression by transcriptional upregulation of cyclin A1, promoting proliferation of human ATC cells. Silencing FoxO3a with a reverse genetics approach leads to downregulation of CCNA1 mRNA and protein. These combined data suggest an entirely novel function for FoxO3a in ATC promotion by enhancing cell cycle progression and tumor growth through transcriptional upregulation of cyclin A1. This is clinically relevant since we detected highly elevated CCNA1 mRNA and protein levels in tumor tissues of ATC patients. Our data indicate therapeutic inactivation of FoxO3a may lead to attenuation of tumor expansion in ATC. This new paradigm also suggests caution in relation to current dogma focused upon reactivation of FoxO3a as a therapeutic strategy against cancers harboring active PI3-K and Akt signaling pathways.
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Affiliation(s)
- Laura A Marlow
- Department of Cancer Biology, Mayo Clinic Comprehensive Cancer Center, Jacksonville, FL 32224, USA
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7
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Federico M, Symonds CE, Bagella L, Rizzolio F, Fanale D, Russo A, Giordano A. R-Roscovitine (Seliciclib) prevents DNA damage-induced cyclin A1 upregulation and hinders non-homologous end-joining (NHEJ) DNA repair. Mol Cancer 2010; 9:208. [PMID: 20684776 PMCID: PMC3224749 DOI: 10.1186/1476-4598-9-208] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2010] [Accepted: 08/04/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND CDK-inhibitors can diminish transcriptional levels of cell cycle-related cyclins through the inhibition of E2F family members and CDK7 and 9. Cyclin A1, an E2F-independent cyclin, is strongly upregulated under genotoxic conditions and functionally was shown to increase NHEJ activity. Cyclin A1 outcompetes with cyclin A2 for CDK2 binding, possibly redirecting its activity towards DNA repair. To see if we could therapeutically block this switch, we analyzed the effects of the CDK-inhibitor R-Roscovitine on the expression levels of cyclin A1 under genotoxic stress and observed subsequent DNA damage and repair mechanisms. RESULTS We found that R-Roscovitine alone was unable to alter cyclin A1 transcriptional levels, however it was able to reduce protein expression through a proteosome-dependent mechanism. When combined with DNA damaging agents, R-Roscovitine was able to prevent the DNA damage-induced upregulation of cyclin A1 on a transcriptional and post-transcriptional level. This, moreover resulted in a significant decrease in non-homologous end-joining (NHEJ) paired with an increase in DNA DSBs and overall DNA damage over time. Furthermore, microarray analysis demonstrated that R-Roscovitine affected DNA repair mechanisms in a more global fashion. CONCLUSIONS Our data reveal a new mechanism of action for R-Roscovitine on DNA repair through the inhibition of the molecular switch between cyclin A family members under genotoxic conditions resulting in reduced NHEJ capability.
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Affiliation(s)
- Mario Federico
- Sbarro Health Research Organization, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, Pennsylvania, USA.
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Wang Z, Qi Y, Chen Q, Yang D, Tang S, Jin X, Gao J, Fu J, Zhou Z, Wang J, Xiao X. Cyclin A is essential for the p53-modulated inhibition from benzo(a)pyrene toxicity in A549 cells. Toxicology 2009; 256:1-6. [DOI: 10.1016/j.tox.2008.10.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2008] [Revised: 10/18/2008] [Accepted: 10/25/2008] [Indexed: 12/23/2022]
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9
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Antimycin A as a mitochondria damage agent induces an S phase arrest of the cell cycle in HeLa cells. Life Sci 2008; 83:346-55. [DOI: 10.1016/j.lfs.2008.06.023] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Revised: 06/10/2008] [Accepted: 06/25/2008] [Indexed: 01/15/2023]
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10
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Wegiel B, Bjartell A, Culig Z, Persson JL. Interleukin-6 activates PI3K/Akt pathway and regulates cyclin A1 to promote prostate cancer cell survival. Int J Cancer 2008; 122:1521-9. [PMID: 18027847 DOI: 10.1002/ijc.23261] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Interleukin-6 (IL6) is a growth and survival factor in human prostate cancer (PCa) cells with aggressive phenotypes and has been implicated in the progression of hormone refractory PCas. In the present study, we characterized the IL6-triggered PI3K/Akt and MAPK/Erk signaling. We identified the A-type cyclin, cyclin A1 as an important downstream target of PI3K/Akt. Treatment of cells with PI3K inhibitor or cotransfection with a vector expressing wild-type PTEN decreased cyclin A1 promoter activity. Cyclin A1 promoter activity and its expression were upregulated by constitutively active myristoylated Akt and were downregulated by dominant negative Akt in response to IL6 stimulation. LNCaP cells overexpressing cyclin A1 are resistant to camptothecin-induced apoptosis. Conversely, targeted knockdown of cyclin A1 via shRNA in LNCaP IL6+ cells resulted in decreased survival after treatment with camptothecin. This suggests that cyclin A1 is an important downstream target of PI3K/Akt that transduces survival signals in response to IL6 stimulation. Xenograft tumors generated from LNCaP-IL6+ cells expressing IL6 had higher levels of cyclin A1 and had rapid tumor growth compared to LNCaP xenograft tumors. Taken together, IL6 might utilize PI3K/Akt and cyclin A1 to promote tumor cell survival in PCa.
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Affiliation(s)
- Barbara Wegiel
- Division of Pathology, Department of Laboratory Medicine, Lund University, University Hospital, Malmö, Sweden
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11
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Yang D, Qi Y, Chen Q, Wang Z, Jin X, Gao J, Fu J, Xiao X, Zhou Z. The over-expression of p53 H179Y residue mutation causes the increase of cyclin A1 and Cdk4 expression in HELF cells. Mol Cell Biochem 2007; 304:219-26. [PMID: 17530187 DOI: 10.1007/s11010-007-9503-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2007] [Accepted: 04/27/2007] [Indexed: 01/10/2023]
Abstract
Down-regulation of p53 expression has been found in a broad range of human cancers and cell proliferation disorders, indicating that p53 plays a key role in cell cycle regulation and tumor suppression. In our current study, we transfected human embryonic lung fibroblast (HELF) cells with pcDNA3-wild-type p53 (pcDNA3-wtp53) plasmid, or pcDNA3-H179Y-mutated p53 (pcDNA3-mtp53) plasmid that mimics the mutation found in some human lung tumors, and further studied the role of p53 in the regulation of cell proliferation. Over expression of wild-type p53 caused cell cycle arrest at G1 phase with reduced cell size, decreased expression of cyclin D3, cyclin E, Cdk2 and Cdk4, and increased expression of p21. In contrast, over expression of H179Y-mutant p53 promoted G1 to S phase transition with enlarged cell size and increased cyclin A1 and Cdk4 expression in HELF cells. These results indicate that mutation at the p53 H179Y residue up-regulates cyclin A1 and Cdk4 expression, and promotes HELF cell proliferation.
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Affiliation(s)
- Di Yang
- Department of Pharmacology and Toxicology, College of Veterinary Medicine, China Agricultural University, Beijing 100094, P.R. China
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