1
|
Zhang M, Zhang L, Zhou M, Wang E, Meng B, Li Q, Wang X, Wang Y, Li Q. Anti‑silencing function 1B promotes the progression of pancreatic cancer by activating c‑Myc. Int J Oncol 2023; 62:8. [PMID: 36416310 PMCID: PMC9728557 DOI: 10.3892/ijo.2022.5456] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 08/31/2022] [Indexed: 11/18/2022] Open
Abstract
The present study aimed to explore the role of histone chaperone anti‑silencing function 1B (ASF1B) in pancreatic cancer and the underlying mechanism. The biological function of ASF1B was investigated in pancreatic cancer cell lines (PANC‑1 and SW1990) and a mouse xenograft model. Chromatin immunoprecipitation was used to detect the effect of ASF1B on the transcriptional activity of c‑Myc. ASF1B was highly expressed in pancreatic adenocarcinoma (PAAD) samples from The Cancer Genome Atlas. ASF1B expression was positively associated with poor survival rates in patients with PAAD. Silencing of ASF1B in PANC‑1 and SW1990 cells inhibited cell proliferation, migration and invasion, and induced apoptosis. Mechanistically, ASF1B increased H3K56 acetylation (H3K56ac) in a CREB‑binding protein (CBP)‑dependent manner. ASF1B promoted H3K56ac at the c‑Myc promoter and increased c‑Myc expression. In PANC‑1 and SW1990 cells, the CBP inhibitor curcumin and the c‑Myc inhibitor 10058‑F4 reversed the promoting effects of ASF1B on cell proliferation, migration and invasion. In the mouse xenograft model, ASF1B silencing inhibited tumor growth, and was associated with low H3K56ac and c‑Myc expression. ASF1B promoted pancreatic cancer progression by activating c‑Myc via CBP‑mediated H3K56ac.
Collapse
Affiliation(s)
- Min Zhang
- Department of Hepatobiliary and Pancreatic Surgery, Cancer Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450008
| | - Luyang Zhang
- Department of Hepatobiliary and Pancreatic Surgery, Cancer Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450008
| | - Minghe Zhou
- Department of Hepatobiliary and Pancreatic Surgery, Cancer Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450008
| | - Enze Wang
- Department of Hepatobiliary and Pancreatic Surgery, Cancer Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450008
| | - Bo Meng
- Department of Hepatobiliary and Pancreatic Surgery, Cancer Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450008
| | - Qingjun Li
- Department of Hepatobiliary and Pancreatic Surgery, Cancer Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450008
| | - Xiaoqian Wang
- Department of Hepatobiliary and Pancreatic Surgery, Cancer Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450008
| | - Yunjian Wang
- Department of Hepatobiliary and Pancreatic Surgery, Cancer Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450008
| | - Qiong Li
- Key Laboratory for Medical Tissue Regeneration of Henan Province, Xinxiang Medical College, Xinxiang, Henan 453003, P.R. China
| |
Collapse
|
2
|
Li Y, Su Y, Zhao Y, Hu X, Zhao G, He J, Wan S, Lü M, Cui H. Demethylzeylasteral inhibits proliferation, migration, and invasion through FBXW7/c-Myc axis in gastric cancer. MedComm (Beijing) 2021; 2:467-480. [PMID: 34766156 PMCID: PMC8554662 DOI: 10.1002/mco2.73] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 04/05/2021] [Accepted: 04/07/2021] [Indexed: 12/14/2022] Open
Abstract
Gastric cancer (GC) is one of the most familiar malignancy in the digestive system. Demethylzeylasteral (Dem), a natural functional monomer extracted from Tripterygium wilfordii Hook F, shows anti‐tumor effects in a variety of cancers, including GC, however, with the underlying mechanism poorly understood. In our study, we show that Dem inhibits the proliferation, migration, and invasion of GC cells, which are mediated by down‐regulating c‐Myc protein levels. Mechanistically, Dem reduces the stability of c‐Myc by up‐regulating FBXW7, an E3 ubiquitin ligase. Moreover, in xenograft tumor model experiment, Dem also inhibits GC, which depends on suppressing c‐Myc expression. Finally, Dem enhances GC cell chemosensitivity to the combination treatment of 5‐Fluorouracil (5‐Fu) and doxorubicin (DOX) in vitro. Together, Dem exerts anti‐neoplastic activities through destabilizing and suppressing c‐Myc, establishing a theory foundation for using it in future treatment of GC.
Collapse
Affiliation(s)
- Yongsen Li
- State Key Laboratory of Silkworm Genome Biology College of Sericulture Textile and Biomass sciences Southwest University Chongqing China
| | - Yongyue Su
- Department of Orthopaedic 920th Hospital of Joint Logistics Support Force of Chinese People's Liberation Army Kunming China
| | - Yuzu Zhao
- State Key Laboratory of Silkworm Genome Biology College of Sericulture Textile and Biomass sciences Southwest University Chongqing China
| | - Xiaosong Hu
- State Key Laboratory of Silkworm Genome Biology College of Sericulture Textile and Biomass sciences Southwest University Chongqing China
| | - Gaichao Zhao
- State Key Laboratory of Silkworm Genome Biology College of Sericulture Textile and Biomass sciences Southwest University Chongqing China
| | - Jiang He
- State Key Laboratory of Silkworm Genome Biology College of Sericulture Textile and Biomass sciences Southwest University Chongqing China
| | - Sicheng Wan
- State Key Laboratory of Silkworm Genome Biology College of Sericulture Textile and Biomass sciences Southwest University Chongqing China
| | - Muhan Lü
- Department of Gastroenterology The Affiliated Hospital of Southwest Medical University Luzhou China
| | - Hongjuan Cui
- State Key Laboratory of Silkworm Genome Biology College of Sericulture Textile and Biomass sciences Southwest University Chongqing China.,Department of Gastroenterology The Affiliated Hospital of Southwest Medical University Luzhou China.,Cancer Centre Medical Research Institute Southwest University Chongqing China
| |
Collapse
|
3
|
Dai L, Wang W, Liu Y, Song K, Di W. Inhibition of sphingosine kinase 2 down-regulates ERK/c-Myc pathway and reduces cell proliferation in human epithelial ovarian cancer. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:645. [PMID: 33987343 PMCID: PMC8106111 DOI: 10.21037/atm-20-6742] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Background Epithelial ovarian cancer (EOC) is the leading cause of death from female cancers. In our previous study, sphingosine kinase 2 (SphK2) inhibitor was shown to display anti-EOC activities. The purpose of this study was to evaluate further the expression characteristics and clinical significance of SphK2 in EOC and to explore the roles and underlying mechanisms of SphK2 in EOC cell survival. Methods The expression of SphK2 was examined by immunohistochemistry (IHC) and Western blot, and its clinical implications and prognostic significance were analyzed. We performed a cellular proliferation assay, and a mouse xenograft model was established to confirm the roles of SphK2 in vitro and in vivo. Cell cycle analysis, apoptosis assay, and Western blot were performed to examine cell cycle progression and apoptosis rate. Gene set enrichment analysis (GSEA), and Western blot were used to investigate the downstream signaling pathways related to SphK2 function. Results The expression level of SphK2 was shown to be associated with stage, histological grade, lymph node metastasis, and ascites status. More importantly, a high SphK2 expression level was a prognostic indicator of overall survival (OS) and relapse-free survival (RFS). Moreover, knockdown of SphK2 arrested cell cycle progression and inhibited EOC cell proliferation both in vitro and in vivo. Furthermore, ERK/c-Myc, the key pathway in EOC progression, was important for SphK2-mediated mitogenic action in EOC cells. Conclusions Our findings provided the first evidence that SphK2 played a crucial role in EOC proliferation by regulating the ERK/c-Myc pathway. This indicated that SphK2 might serve as a prognostic marker and potential therapeutic target in EOC.
Collapse
Affiliation(s)
- Lan Dai
- Department of Obstetrics and Gynecology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Gynecologic Oncology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Wenjing Wang
- Department of Obstetrics and Gynecology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Gynecologic Oncology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yixuan Liu
- Department of Obstetrics and Gynecology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Gynecologic Oncology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Keqi Song
- Department of Obstetrics and Gynecology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Gynecologic Oncology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Wen Di
- Department of Obstetrics and Gynecology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Gynecologic Oncology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,State Key Laboratory of Oncogene and Related Genes, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| |
Collapse
|
4
|
Abstract
Abstract
Background: Helicobacter pylori (H. pylori) may be associated with colorectal cancer. However, the underlying mechanisms are still unclear. Objectives: Explore the serostatus of H. pylori cytotoxicity-associated gene A product (CagA) in patients with colorectal carcinoma, and assess the association of H. pylori with colorectal cancer via c-Myc and MUC-2 proteins at tumor tissues. Methods: H. pylori CagA IgG antibodies were screened using enzyme-linked immunosorbent assay (ELISA) in 30 patients with colorectal carcinoma and 30 cancer-free control subjects. Paraffin-embedded blocks were examined for the expression of c-Myc and MUC-2 protein by immunohistochemistry. Results: H. pylori CagA seropositivity increased significantly among colorectal cancer patients (p <0.05). The expression of c-Myc and MUC-2 in colorectal carcinoma patients was over-expressed (80%), and downexpressed (63%) in resection margins (p <0.05). c-Myc over-expression and MUC-2 down-expression were associated with CagA-positive rather than CagA-negative H. pylori patients. In 16 CagA seropositive vs. 14 CagA seronegative patients, the expression rate was 97.3% vs. 64.2% and 33.3% vs. 78.5% for cMyc and MUC-2, respectively. CagA IgG level was significantly higher in positive than in negative c-Myc patients (p= 0.036), and in negative than in positive MUC-2 patients (p= 0.044). c-Myc and MUC-2 were positively and inversely correlated with CagA IgG level (p <0.05). Conclusions: CagA-seropositive H. pylori is most probably associated with colorectal cancer development. Part of the underlying mechanism for such association might be via alterations in expression of MUC-2, which depletes the mucous protective layer in the colo-rectum, and c-Myc, which stimulates the growth of cancerous cells.
Collapse
|
5
|
Marzo-Mas A, Falomir E, Murga J, Carda M, Marco JA. Effects on tubulin polymerization and down-regulation of c-Myc, hTERT and VEGF genes by colchicine haloacetyl and haloaroyl derivatives. Eur J Med Chem 2018; 150:591-600. [PMID: 29550732 DOI: 10.1016/j.ejmech.2018.03.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 03/01/2018] [Accepted: 03/05/2018] [Indexed: 11/26/2022]
Abstract
Several colchicine analogues in which the N-acetyl residue has been replaced by haloacetyl, cyclohexylacetyl, phenylacetyl and various aroyl moieties have been synthesized. The cytotoxic activities of the synthesized compounds have been measured on three tumor cell lines (HT-29, MCF-7 and A549) and on one non-tumor cell line (HEK-293). These compounds exhibit high antiproliferative activities at the nanomolar level, in many cases with a higher potency than colchicine itself. Some of the compounds, particularly the haloacetyl derivatives, inhibit the polymerization of tubulin in a similar manner as colchicine. As regards the cell cycle, the most active compounds are the chlorobenzoyl and bromobenzoyl derivatives, which cause cell cycle arrest at the G2/M phase when tested at 20 nM, and the bromoacetyl derivative, which arrests the cell cycle at 15 nM. In addition, these colchicine derivatives have shown fairly active downregulating the expression of the c-Myc, hTERT and VEGF genes, as well as VEGF protein secretion, at very low concentrations.
Collapse
Affiliation(s)
- Ana Marzo-Mas
- Depart. de Q. Inorgánica y Orgánica, Univ. Jaume I, E-12071, Castellón, Spain
| | - Eva Falomir
- Depart. de Q. Inorgánica y Orgánica, Univ. Jaume I, E-12071, Castellón, Spain.
| | - Juan Murga
- Depart. de Q. Inorgánica y Orgánica, Univ. Jaume I, E-12071, Castellón, Spain.
| | - Miguel Carda
- Depart. de Q. Inorgánica y Orgánica, Univ. Jaume I, E-12071, Castellón, Spain
| | - J Alberto Marco
- Depart. de Q. Orgánica, Univ. de Valencia, E-46100, Burjassot, Valencia, Spain
| |
Collapse
|
6
|
Qiu H, Li J, Clark LH, Jackson AL, Zhang L, Guo H, Kilgore JE, Gehrig PA, Zhou C, Bae-Jump VL. JQ1 suppresses tumor growth via PTEN/PI3K/AKT pathway in endometrial cancer. Oncotarget 2018; 7:66809-66821. [PMID: 27572308 PMCID: PMC5341839 DOI: 10.18632/oncotarget.11631] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 08/10/2016] [Indexed: 01/16/2023] Open
Abstract
Overexpression of c-Myc is associated with worse outcomes in endometrial cancer, indicating that c-Myc may be a promising target for endometrial cancer therapy. A novel small molecule, JQ1, has been shown to block BRD4 resulting in inhibition of c-Myc expression and tumor growth. Thus, we investigated whether JQ1 can inhibit endometrial cancer growth in cell culture and xenograft models. In PTEN-positive endometrial cancer cells, JQ1 significantly suppressed cell proliferation via induction of G1 phase arrest and apoptosis in a dose-dependent manner, accompanied by a sharp decline in cyclin D1 and CDK4 protein expression. However, PTEN-negative endometrial cancer cells exhibited intrinsic resistance to JQ1, despite significant c-Myc inhibition. Moreover, we found that PTEN and its downstream PI3K/AKT signaling targets were modulated by JQ1, as evidenced by microarray analysis. Silencing of PTEN in PTEN-positive endometrial cancer cells resulted in resistance to JQ1, while upregulation of PTEN in PTEN-negative endometrial cancer cells increased sensitivity to JQ1. In xenografts models of PTEN-positive and PTEN-knock-in endometrial cancer, JQ1 significantly upregulated the expression of PTEN, blocked the PI3K/AKT signaling pathway and suppressed tumor growth. These effects were attenuated in PTEN-negative and PTEN-knockdown xenograft models. Thus, JQ1 resistance appears to be highly associated with the status of PTEN expression in endometrial cancer. Our findings suggest that targeting BRD4 using JQ1 might serve as a novel therapeutic strategy in PTEN-positive endometrial cancers.
Collapse
Affiliation(s)
- Haifeng Qiu
- Department of Obstetrics and Gynecology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Division of Gynecological Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jing Li
- Department of Oncology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Leslie H Clark
- Division of Gynecological Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Amanda L Jackson
- Division of Gynecological Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Lu Zhang
- Division of Gynecological Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Department of Gynecologic Oncology, Shandong Cancer Hospital and Institute, Jinan, China
| | - Hui Guo
- Division of Gynecological Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Department of Gynecologic Oncology, Shandong Cancer Hospital and Institute, Jinan, China
| | - Joshua E Kilgore
- Division of Gynecological Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Paola A Gehrig
- Division of Gynecological Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Chunxiao Zhou
- Division of Gynecological Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Lineberger Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Victoria L Bae-Jump
- Division of Gynecological Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Lineberger Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| |
Collapse
|
7
|
Wang H, Sharma L, Lu J, Finch P, Fletcher S, Prochownik EV. Structurally diverse c-Myc inhibitors share a common mechanism of action involving ATP depletion. Oncotarget 2016; 6:15857-70. [PMID: 26036281 PMCID: PMC4599242 DOI: 10.18632/oncotarget.4327] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 04/10/2015] [Indexed: 12/29/2022] Open
Abstract
The c-Myc (Myc) oncoprotein is deregulated in a large proportion of diverse human cancers. Considerable effort has therefore been directed at identifying pharmacologic inhibitors as potential anti-neoplastic agents. Three such groups of small molecule inhibitors have been described. The first is comprised of so-called “direct” inhibitors, which perturb Myc's ability to form productive DNA-binding heterodimers in association with its partner, Max. The second group is comprised of indirect inhibitors, which largely function by targeting the BET-domain protein BRD4 to prevent the proper formation of transcriptional complexes that assemble in response to Myc-Max DNA binding. Thirdly, synthetic lethal inhibitors cause the selective apoptosis of Myc over-expressing either by promoting mitotic catastrophe or altering Myc protein stability. We report here a common mechanism by which all Myc inhibitors, irrespective of class, lead to eventual cellular demise. This involves the depletion of ATP stores due to mitochondrial dysfunction and the eventual down-regulation of Myc protein. The accompanying metabolic de-regulation causes neutral lipid accumulation, cell cycle arrest, and an attempt to rectify the ATP deficit by up-regulating AMP-activated protein kinase (AMPK). These responses are ultimately futile due to the lack of functional Myc to support the requisite anabolic response. Finally, the effects of Myc depletion on ATP levels, cell cycle arrest, differentiation and AMPK activation can be mimicked by pharmacologic inhibition of the mitochondrial electron transport chain without affecting Myc levels. Thus, all Myc inhibitors promote a global energy collapse that appears to underlie many of their phenotypic consequences.
Collapse
Affiliation(s)
- Huabo Wang
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Lokendra Sharma
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Jie Lu
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Paul Finch
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Steven Fletcher
- Department of Pharmaceutical Sciences, The University of Maryland School of Pharmacy, Baltimore, MD, USA.,The Greenebaum Cancer Center, Baltimore, MD, USA
| | - Edward V Prochownik
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center, Pittsburgh, PA, USA.,Department of Microbiology and Molecular Genetics, The University of Pittsburgh, Pittsburgh, PA, USA.,The University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA
| |
Collapse
|
8
|
Child HW, Hernandez Y, Conde J, Mullin M, Baptista P, de la Fuente JM, Berry CC. Gold nanoparticle-siRNA mediated oncogene knockdown at RNA and protein level, with associated gene effects. Nanomedicine (Lond) 2015; 10:2513-25. [DOI: 10.2217/nnm.15.95] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Aims: RNAi is a powerful tool for gene silencing that can be used to reduce undesirable overexpression of oncogenes as a novel form of cancer treatment. However, when using RNAi as a therapeutic tool there is potential for associated gene effects. This study aimed to utilize gold nanoparticles to deliver siRNA into HeLa cells. Results: Knockdown of the c-myc oncogene by RNAi, at the RNA, protein and cell proliferation level was achieved, while also identifying associated gene responses. Discussion: The gold nanoparticles used in this study present an excellent delivery platform for siRNA, but do note associated gene changes. Conclusion: The study highlights the need to more widely assess the cell physiological response to RNAi treatment, rather than focus on the immediate RNA levels.
Collapse
Affiliation(s)
| | - Yulán Hernandez
- Instituto de Nanociencia de Aragón, University of Zaragoza, C/Mariano Esquillor s/n Zaragoza, Spain
| | - João Conde
- Massachusetts Institute of Technology, Institute for Medical Engineering & Science, Harvard-MIT Division for Health Sciences & Technology, Cambridge, MA 02139-4307, USA
| | - Margaret Mullin
- Integrated Microscopy Facility, Joseph Black Building, Glasgow University, G12 8QQ, UK
| | - Pedro Baptista
- UCIBIO, CIGMH, Departamento de Ciencias da Vida, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, Portugal
| | - Jesus Maria de la Fuente
- Instituto de Nanociencia de Aragón, University of Zaragoza, C/Mariano Esquillor s/n Zaragoza, Spain
- Instituto de Ciencia de Materiales de Aragón (ICMA), CSIC-Universidad de Zaragoza, c/Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | | |
Collapse
|
9
|
Wu Z, Wang H, Fang S, Xu C. MiR-449c inhibits gastric carcinoma growth. Life Sci 2015; 137:14-9. [PMID: 26141986 DOI: 10.1016/j.lfs.2015.06.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 06/13/2015] [Accepted: 06/22/2015] [Indexed: 10/23/2022]
Abstract
AIMS Gastric carcinoma (GC) is among the leading causes of cancer-related deaths in China. Growing evidence indicates that dysregulation of miRNAs contributes to GC development. Although it has been shown that miR-449c acts as a tumor suppressor in lung cancer, the role of miR-449c in GC remains unclear. MAIN METHODS Here, we analyzed miR-449c levels in GC tissues and cell lines by RT-qPCR. We also overexpressed and inhibited miR-449c by transfecting miRNA mimics and antisense oligonucleotides (ASO), respectively. Cell growth was analyzed by MTT assay, and cell apoptosis was evaluated by FACS analysis. MiR-449c target genes were predicted using bioinformatics algorithms and confirmed by a dual luciferase reporter assay. KEY FINDINGS We detected lower miR-449c levels in GC tissues; the low miR-449c levels correlated with low survival rate. Overexpression of miR-449c inhibited cell growth and promoted apoptosis, while depletion of miR-449c increased cell growth and suppressed apoptosis. Moreover, the 3' UTR of MET, an oncogene that activates tumor cell growth, appeared to be targeted by miR-449c. SIGNIFICANCE Together, we showed that the reduced miR-449c levels in GC tissues promote GC growth, which possibly contributes to the low survival rate of GC patients. Mechanistically, miR-449c may target MET to suppress GC cell growth.
Collapse
Affiliation(s)
- Zhiming Wu
- Department of Surgery, Shaoxing Hospital of China Medical University, 1 Huayu Road, Shaoxing 312030, China.
| | - Huangen Wang
- Department of Surgery, Shaoxing Hospital of China Medical University, 1 Huayu Road, Shaoxing 312030, China
| | - Sunyang Fang
- Department of Surgery, Shaoxing Hospital of China Medical University, 1 Huayu Road, Shaoxing 312030, China
| | - Chaoyang Xu
- Department of Breast and Thyroid Surgery, Shaoxing People's Hospital, 568 Zhongxingbei Road, Shaoxing 312000, China
| |
Collapse
|
10
|
Xu XH, Pan W, Kang LH, Feng H, Song YQ. Association of annexin A2 with cancer development (Review). Oncol Rep 2015; 33:2121-8. [PMID: 25760910 DOI: 10.3892/or.2015.3837] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 02/20/2015] [Indexed: 01/11/2023] Open
Abstract
Annexin A2 (ANXA2) is a well-known calcium-dependent phospholipid binding protein widely distributed in the nucleus, cytoplasm and extracellular surface of various eukaryotic cells. It has been recognized as a pleiotropic protein affecting a wide range of molecular and cellular processes. Dysregulation and abnormal expression of ANXA2 are linked to a large number of prevalent diseases, including autoimmune and neurodegenerative disease, antiphospholipid syndrome, inflammation, diabetes mellitus and a series of cancers. Accumulating data suggest that ANXA2 is aberrantly expressed in a wide spectrum of cancers, and exerts profound effects on tumor cell adhesion, proliferation, apoptosis, invasion and metastasis as well as tumor neovascularization via different modes of action. However, despite significant research, our knowledge of the mechanism by which ANXA2 participates in cancer development remains fragmented. The present review systematically summarizes the effects of ANXA2 on tumor progression, in an attempt to gain an improved understanding of the underlying mechanisms and to provide a potential effective target for cancer therapy.
Collapse
Affiliation(s)
- Xiao-Heng Xu
- Cancer Center, The First Hospital of Jilin University, Changchun, Jilin, P.R. China
| | - Wei Pan
- Department of Pediatrics, The Second Hospital of Jilin University, Changchun, Jilin, P.R. China
| | - Li-Hua Kang
- Cancer Center, The First Hospital of Jilin University, Changchun, Jilin, P.R. China
| | - Hui Feng
- Cancer Center, The First Hospital of Jilin University, Changchun, Jilin, P.R. China
| | - Yan-Qiu Song
- Cancer Center, The First Hospital of Jilin University, Changchun, Jilin, P.R. China
| |
Collapse
|
11
|
The influence of mtDNA deletion on lung cancer cells under the conditions of hypoxia and irradiation. Lung 2014; 192:997-1004. [PMID: 25218334 DOI: 10.1007/s00408-014-9639-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Accepted: 08/12/2014] [Indexed: 10/24/2022]
Abstract
PURPOSE This study was to evaluate the influence of mtDNA deletion on the lung cancer cells under the conditions of hypoxia or irradiation. METHOD The treatment conditions of lung cancer cell lines with (A549) and without mtDNA (ρ0A549: obtained by inducing from A549) included 2 h of hypoxia and 4 Gy irradiation (group 1: without treatment; group 2: 2 h of hypoxia; group 3: 4 Gy irradiation; group 4: 2 h of hypoxia plus 4 Gy irradiation). The Human OneArray™ microarray was used to hybridize with the Cy5-labeled aRNA in microarray sample preparation. Differentially expressed genes (DEGs) between the lung cancer cells with and without mtDNA were identified using NOISeq package in R. Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed using the online tool of DAVID. RESULT In the KEGG pathway analysis of down-regulated DEGs, nineteen pathways were simultaneously enriched in the four groups, which were mainly metabolism- and biosynthesis-related pathways. Nine lung cancer-related pathways were enriched in group 4, and more cancer-associated DEGs, such as MYC, MAX, and E2F1 were found in group 4 than in the other groups. CONCLUSION The mtDNA deletion could inhibit the biosynthesis and metabolism of lung cancer cells and promote the effect of hypoxia and radiation on lung cancer cells. MYC might be the key gene of the cooperation of hypoxia and radiation and MYC, MAX, and E2F1 might play roles in hypoxia- and radiation-induced cell death in lung cancer cells without mtDNA.
Collapse
|
12
|
Gai W, Yang Q, Xiang J, Sun H, Shang Q, Li Q, Jiang W, Guan A, Zhang H, Tang Y, Xu G. Roles of flanking sequences in the binding between unimolecular parallel-stranded G-quadruplexes and ligands. ACTA ACUST UNITED AC 2013. [DOI: 10.1007/s11434-012-5639-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
13
|
Zhang Y, Chen L, Yang S, Fang D. E2F1: a potential negative regulator of hTERT transcription in normal cells upon activation of oncogenic c-Myc. Med Sci Monit 2012; 18:RA12-15. [PMID: 22207128 PMCID: PMC3560676 DOI: 10.12659/msm.882192] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Previous studies have revealed that the link between c-Myc and E2F1 pathway plays a pivotal role in regulating cell growth and death. Human telomerase reverse transcriptase (hTERT), activation of which is required for cell immortalization and transformation, has been confirmed to be a direct transcriptional target of c-Myc. It is of note that E2F1, which is also a direct transcriptional target of c-Myc, can bind the hTERT promoter and repress its expression. Thus, although oncogene c-Myc can be activated in normal cells, for the subsequent induction of E2F1, it may still be insufficient to trigger the expression of hTERT. This negative feedback regulation, if it exists, may be another mechanism for normal cells to control the transmission of c-Myc-mediated oncogenic signals. In this article, we reviewed current knowledge about the crosstalk among c-Myc, E2F1 and hTERT, with an emphasis on the hypothesis that E2F1 negatively regulates c-Myc-induced hTERT transcription. Additionally, we postulated that the miR-17-92 cluster-mediated regulation of c-Myc and E2F1 expression may be of particular importance for the repression of hTERT transcription.
Collapse
Affiliation(s)
- Yafei Zhang
- Department of Gastroenterology, Southwest Hospital, Third Military Medical University, Chongqing, China
| | | | | | | |
Collapse
|
14
|
Kharazmi J, Moshfegh C, Brody T. Identification of cis-Regulatory Elements in the dmyc Gene of Drosophila Melanogaster. GENE REGULATION AND SYSTEMS BIOLOGY 2012; 6:15-42. [PMID: 22267917 PMCID: PMC3256997 DOI: 10.4137/grsb.s8044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Myc is a crucial regulator of growth and proliferation during animal development. Many signals and transcription factors lead to changes in the expression levels of Drosophila myc, yet no clear model exists to explain the complexity of its regulation at the level of transcription. In this study we used Drosophila genetic tools to track the dmyc cis-regulatory elements. Bioinformatics analyses identified conserved sequence blocks in the noncoding regions of the dmyc gene. Investigation of lacZ reporter activity driven by upstream, downstream, and intronic sequences of the dmyc gene in embryonic, larval imaginal discs, larval brain, and adult ovaries, revealed that it is likely to be transcribed from multiple transcription initiation units including a far upstream regulatory region, a TATA box containing proximal complex and a TATA-less downstream promoter element in conjunction with an initiator within the intron 2 region. Our data provide evidence for a modular organization of dmyc regulatory sequences; these modules will most likely be required to generate the tissue-specific patterns of dmyc transcripts. The far upstream region is active in late embryogenesis, while activity of other cis elements is evident during embryogenesis, in specific larval imaginal tissues and during oogenesis. These data provide a framework for further investigation of the transcriptional regulatory mechanisms of dmyc.
Collapse
Affiliation(s)
- Jasmine Kharazmi
- Biotechnopark Zurich, Molecular Biology Laboratory, University of Zurich-Irchel, Zurich, Switzerland
| | | | | |
Collapse
|
15
|
Tagami T, Suzuki T, Hirose K, Barichello JM, Yamazaki N, Asai T, Oku N, Ishida T, Kiwada H. Argonaute2 is a potential target for siRNA-based cancer therapy for HT1080 human fibrosarcoma. Drug Deliv Transl Res 2011; 1:277-88. [DOI: 10.1007/s13346-011-0025-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
16
|
Akimov IA, Kabilova TO, Vlassov VV, Chernolovskaya EL. Inhibition of human cancer-cell proliferation by long double-stranded RNAs. Oligonucleotides 2010; 19:31-40. [PMID: 19125638 DOI: 10.1089/oli.2008.0151] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Three different enzymatically synthesized long double-stranded RNAs (dsRNAs) [448 bp homologous to the third exon of c-myc messenger RNA (mRNA) (dsMyc); 473 bp homologous to enhanced green fluorescent protein (EGFP) mRNA (dsEGFP) and control interferon inducer poly(I:C)] were studied for antiproliferative and gene-silencing activities in KB-3-1, SK-N-MC, and IMR-32 human cancer cell lines. Simple incubation with these dsRNAs did not affect the expression of c-myc gene and the proliferation of KB-3-1 and IMR-32 cells, but inhibited the proliferation of SK-N-MC cells. Transfection of KB-3-1 and SK-N-MC cells using Oligofectamine-dsRNAs complexes resulted in dose-dependent inhibition of c-myc and beta-actin genes expression and proliferation. The data show that dsMyc, acting both as interferon inducer and as gene-specific interfering RNA, is more effective as c-myc inhibitor than other tested dsRNAs. The most efficient inhibition of proliferation was displayed by dsEGFP RNA, dsMyc and poly(I:C) were effective only when used in higher concentrations. Our data indicate that transfection of studied dsRNAs causes an increase in apoptotic and dead cells number in the cell population. This proapoptotic activity correlates with dsRNAs-induced antiproliferative activity. However the difference in cell growth between dsRNA-treated and Oligofectamine-only treated cells can not be attributed only to the loss of cells due to the apoptosis; it also indicates some retardation of cell cycle progression caused by dsRNA.
Collapse
Affiliation(s)
- Ivan A Akimov
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, Novosibirsk, Russia
| | | | | | | |
Collapse
|
17
|
Berger E, Rome S, Vega N, Ciancia C, Vidal H. Transcriptome profiling in response to adiponectin in human cancer-derived cells. Physiol Genomics 2010; 42A:61-70. [DOI: 10.1152/physiolgenomics.00013.2010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The adipocyte-derived hormone adiponectin exerts protective actions in several disorders, including some cancers. However, while growing data suggest that adiponectin could be an effective anticancer agent, its mechanism of action in cancer cells is still poorly known. Here, using microarrays, we identified a set of 1,301 genes commonly modulated in three cancer-derived cell lines in response to short-term stimulation with full-length recombinant human adiponectin. Most of these genes are involved in translation regulation, immune or stress responses, and cell proliferation. Furthermore, among genes linked to disease that were retrieved by functional enrichment tests using text mining based on PubMed analysis, we found that 66% are involved in malignant neoplasms, further supporting the link between adiponectin and cancer mechanisms. Bioinformatic analysis demonstrated the diversity of signaling pathways and transcription factors potentially mediating adiponectin effects on gene expression, illustrating the complexity of adiponectin mechanisms of action in cancer cells.
Collapse
Affiliation(s)
- Emmanuelle Berger
- Université de Lyon, INSERM U870, INRA U1235, Hospices Civils de Lyon, and INSA-Lyon, Lyon, France
| | - Sophie Rome
- Université de Lyon, INSERM U870, INRA U1235, Hospices Civils de Lyon, and INSA-Lyon, Lyon, France
| | - Nathalie Vega
- Université de Lyon, INSERM U870, INRA U1235, Hospices Civils de Lyon, and INSA-Lyon, Lyon, France
| | - Claire Ciancia
- Université de Lyon, INSERM U870, INRA U1235, Hospices Civils de Lyon, and INSA-Lyon, Lyon, France
| | - Hubert Vidal
- Université de Lyon, INSERM U870, INRA U1235, Hospices Civils de Lyon, and INSA-Lyon, Lyon, France
| |
Collapse
|
18
|
Dai J, Hatzakis E, Hurley LH, Yang D. I-motif structures formed in the human c-MYC promoter are highly dynamic--insights into sequence redundancy and I-motif stability. PLoS One 2010; 5:e11647. [PMID: 20657837 PMCID: PMC2906509 DOI: 10.1371/journal.pone.0011647] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Accepted: 06/22/2010] [Indexed: 11/24/2022] Open
Abstract
The GC-rich nuclease hypersensitivity element III1 (NHE III1) of the c-MYC promoter largely controls the transcriptional activity of the c-MYC oncogene. The C-rich strand in this region can form I-motif DNA secondary structures. We determined the folding pattern of the major I-motif formed in the NHE III1, which can be formed at near-neutral pH. While we find that the I-motif formed in the four 3′ consecutive runs of cytosines appears to be the most favored, our results demonstrate that the C-rich strand of the c-MYC NHE III1 exhibits a high degree of dynamic equilibration. Using a trisubstituted oligomer of this region, we determined the formation of two equilibrating loop isomers, one of which contains a flipped-out cytosine. Our results indicate that the intercalative cytosine+–cytosine base pairs are not always necessary for an intramolecular I-motif. The dynamic character of the c-MYC I-motif is intrinsic to the NHE III1 sequence and appears to provide stability to the c-MYC I-motif.
Collapse
Affiliation(s)
- Jixun Dai
- College of Pharmacy, The University of Arizona, Tucson, Arizona, United States of America
| | - Emmanuel Hatzakis
- College of Pharmacy, The University of Arizona, Tucson, Arizona, United States of America
| | - Laurence H. Hurley
- College of Pharmacy, The University of Arizona, Tucson, Arizona, United States of America
- BIO5 Institute, The University of Arizona, Tucson, Arizona, United States of America
- Arizona Cancer Center, The University of Arizona, Tucson, Arizona, United States of America
- Department of Chemistry, The University of Arizona, Tucson, Arizona, United States of America
| | - Danzhou Yang
- College of Pharmacy, The University of Arizona, Tucson, Arizona, United States of America
- BIO5 Institute, The University of Arizona, Tucson, Arizona, United States of America
- Arizona Cancer Center, The University of Arizona, Tucson, Arizona, United States of America
- Department of Chemistry, The University of Arizona, Tucson, Arizona, United States of America
- * E-mail:
| |
Collapse
|
19
|
Albihn A, Johnsen JI, Henriksson MA. MYC in oncogenesis and as a target for cancer therapies. Adv Cancer Res 2010; 107:163-224. [PMID: 20399964 DOI: 10.1016/s0065-230x(10)07006-5] [Citation(s) in RCA: 181] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
MYC proteins (c-MYC, MYCN, and MYCL) regulate processes involved in many if not all aspects of cell fate. Therefore, it is not surprising that the MYC genes are deregulated in several human neoplasias as a result from genetic and epigenetic alterations. The near "omnipotency" together with the many levels of regulation makes MYC an attractive target for tumor intervention therapy. Here, we summarize some of the current understanding of MYC function and provide an overview of different cancer forms with MYC deregulation. We also describe available treatments and highlight novel approaches in the pursuit for MYC-targeting therapies. These efforts, at different stages of development, constitute a promising platform for novel, more specific treatments with fewer side effects. If successful a MYC-targeting therapy has the potential for tailored treatment of a large number of different tumors.
Collapse
Affiliation(s)
- Ami Albihn
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | | | | |
Collapse
|
20
|
Sun D, Hurley LH. The importance of negative superhelicity in inducing the formation of G-quadruplex and i-motif structures in the c-Myc promoter: implications for drug targeting and control of gene expression. J Med Chem 2009; 52:2863-74. [PMID: 19385599 DOI: 10.1021/jm900055s] [Citation(s) in RCA: 288] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The importance of DNA supercoiling in transcriptional regulation has been known for many years, and more recently, transcription itself has been shown to be a source of this superhelicity. To mimic the effect of transcriptionally induced negative superhelicity, the G-quadruplex/i-motif-forming region in the c-Myc promoter was incorporated into a supercoiled plasmid. We show, using enzymatic and chemical footprinting, that negative superhelicity facilitates the formation of secondary DNA structures under physiological conditions. Significantly, these structures are not the same as those formed in single-stranded DNA templates. Together with the recently demonstrated role of transcriptionally induced superhelicity in maintaining a mechanosensor mechanism for controlling the firing rate of the c-Myc promoter, we provide a more complete picture of how c-Myc transcription is likely controlled. Last, these physiologically relevant G-quadruplex and i-motif structures, along with the mechanosensor mechanism for control of gene expression, are proposed as novel mechanisms for small molecule targeting of transcriptional control of c-Myc.
Collapse
Affiliation(s)
- Daekyu Sun
- College of Pharmacy, University of Arizona, Tucson, Arizona 85721, USA.
| | | |
Collapse
|
21
|
Qin Y, Hurley LH. Structures, folding patterns, and functions of intramolecular DNA G-quadruplexes found in eukaryotic promoter regions. Biochimie 2008; 90:1149-71. [PMID: 18355457 DOI: 10.1016/j.biochi.2008.02.020] [Citation(s) in RCA: 373] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2008] [Accepted: 02/22/2008] [Indexed: 12/16/2022]
Abstract
In its simplest form, a DNA G-quadruplex is a four-stranded DNA structure that is composed of stacked guanine tetrads. G-quadruplex-forming sequences have been identified in eukaryotic telomeres, as well as in non-telomeric genomic regions, such as gene promoters, recombination sites, and DNA tandem repeats. Of particular interest are the G-quadruplex structures that form in gene promoter regions, which have emerged as potential targets for anticancer drug development. Evidence for the formation of G-quadruplex structures in living cells continues to grow. In this review, we examine recent studies on intramolecular G-quadruplex structures that form in the promoter regions of some human genes in living cells and discuss the biological implications of these structures. The identification of G-quadruplex structures in promoter regions provides us with new insights into the fundamental aspects of G-quadruplex topology and DNA sequence-structure relationships. Progress in G-quadruplex structural studies and the validation of the biological role of these structures in cells will further encourage the development of small molecules that target these structures to specifically modulate gene transcription.
Collapse
Affiliation(s)
- Yong Qin
- College of Pharmacy, 1703 E. Mabel, University of Arizona, Tucson, AZ 85721, USA
| | | |
Collapse
|
22
|
|
23
|
Dugast-Darzacq C, Grange T, Schreiber-Agus NB. Differential effects of Mxi1-SRalpha and Mxi1-SRbeta in Myc antagonism. FEBS J 2007; 274:4643-53. [PMID: 17697116 DOI: 10.1111/j.1742-4658.2007.05992.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Mxi1 belongs to the Myc-Max-Mad transcription factor network. Two Mxi1 protein isoforms, Mxi1-SRalpha and Mxi1-SRbeta, have been described as sharing many biological properties. Here, we assign differential functions to these isoforms with respect to two distinct levels of Myc antagonism. Unlike Mxi1-SRbeta, Mxi1-SRalpha is not a potent suppressor of the cellular transformation activity of Myc. Furthermore, although Mxi1-SRbeta exhibits a repressive effect on the MYC promoter in transient expression assays, Mxi1-SRalpha activates this promoter. A specific domain of Mxi1-SRalpha contributes to these differences. Moreover, glyceraldehyde-3-phosphate dehydrogenase interacts with Mxi1-SRalpha and enhances its ability to activate the Myc promoter. Our findings suggest that Mxi1 gains functional complexity by encoding isoforms with shared and distinct activities.
Collapse
Affiliation(s)
- Claire Dugast-Darzacq
- Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, NY, USA.
| | | | | |
Collapse
|
24
|
von Rahden BHA, Stein HJ, Pühringer-Oppermann F, Sarbia M. c-myc amplification is frequent in esophageal adenocarcinoma and correlated with the upregulation of VEGF-A expression. Neoplasia 2006; 8:702-7. [PMID: 16984727 PMCID: PMC1584294 DOI: 10.1593/neo.06277] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Deregulation of c-myc plays a major role in the carcinogenesis of human malignancies. We investigated the amplification of the c-myc gene in a surgical series of Barrett cancers. METHODS Primary resected esophageal (Barrett) adenocarcinomas (n = 84) were investigated for c-myc amplification using chromogene in situ hybridization. Tumor samples were assembled in a tissue microarray. c-myc gene dosage was correlated with clinicopathologic parameters, including the survival and gene expression of cyclooxygenases (COX-1 and COX-2) and proangiogenic growth factors (VEGF-A and VEGF-C). RESULTS The majority (70 of 84; 83.3%) exhibited amplification of the c-myc gene. There were low-level amplifications in 63 (75.0%) cases and high-level amplifications in 7 (8.3%) cases. No amplification was found in 14 (16.7%) cases. Tumors without c-myc amplification had lower VEGF-A, VEGF-C, and COX-2 expression levels than tumors with low-level and high-level c-myc amplification (statistically significant for VEGF-A; P = .0348). c-myc amplification was not correlated with clinicopathological parameters or survival. Only diffuse and mixed-type tumors, according to Lauren classification, exhibited c-myc amplifications more frequently (P = .0466). CONCLUSIONS Amplifications of the c-myc gene are frequent in Barrett cancer. c-myc may be involved in the regulation of angiogenesis.
Collapse
|
25
|
Panteleyev AA, Bickers DR. Dioxin-induced chloracne--reconstructing the cellular and molecular mechanisms of a classic environmental disease. Exp Dermatol 2006; 15:705-30. [PMID: 16881967 DOI: 10.1111/j.1600-0625.2006.00476.x] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is among the most toxic pollutants known to date that serves as a prototype for a group of halogenated hydrocarbon compounds characterized by extraordinary environmental persistence and unique ability to concentrate in animal and human tissues. TCDD can elicit a complex array of pleiotropic adverse effects in humans, although chloracne, a specific type of acne-like skin disease, is the only consistent manifestation of dioxin intoxication, thus representing a 'hallmark' of TCDD exposure. Chloracne is considered to be one of the most specific and sensitive biomarkers of TCDD intoxication that allows clinical and epidemiological evaluation of exposure level at threshold doses. The specific cellular and molecular mechanisms involved in pathogenesis of chloracne are still unknown. In this review, we summarize the available clinical data on chloracne and recent progress in understanding the role of the dioxin-dependent pathway in the control of gene transcription and discuss molecular and cellular events potentially involved in chloracne pathogenesis. We propose that the dioxin-induced activation of skin stem cells and a shift in differentiation commitment of their progeny may represent a major mechanism of chloracne development.
Collapse
|
26
|
Arvanitis C, Felsher DW. Conditional transgenic models define how MYC initiates and maintains tumorigenesis. Semin Cancer Biol 2006; 16:313-7. [PMID: 16935001 DOI: 10.1016/j.semcancer.2006.07.012] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
MYC is one of the most commonly overexpressed oncogenes in human cancer. The targeted inactivation of MYC is a possible therapy for neoplasia. Conditional transgenic mouse model systems are tractable methods to precisely dissect how and when the inactivation of MYC might be effective in the treatment for human cancer. From these model systems, several general principles emerge. MYC inactivation stereotypically results in the proliferative arrest, differentiation and/or apoptosis of tumor cells. The specific consequences of MYC inactivation appear to depend both on the type of cancer as well as the constellation of genetic events unique to a given tumor. Tumors can escape from dependence upon MYC by acquiring compensatory genetic events. MYC inactivation can uncover the stem cell properties of tumor cells that differentiate into normal appearing cells. In some cases, these differentiated cells are actually dormant tumor cells that recover their neoplastic properties upon MYC reactivation. In other cases, even brief MYC inactivation is sufficient to induce sustained tumor regression. Insights from conditional transgenic mouse models will be useful in the development of therapies that target MYC for the treatment of cancer.
Collapse
Affiliation(s)
- Constadina Arvanitis
- Department of Molecular Pharmacology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | | |
Collapse
|
27
|
Mo H, Henriksson M. Identification of small molecules that induce apoptosis in a Myc-dependent manner and inhibit Myc-driven transformation. Proc Natl Acad Sci U S A 2006; 103:6344-9. [PMID: 16606833 PMCID: PMC1435363 DOI: 10.1073/pnas.0601418103] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Myc transcription factor plays a central role in the regulation of cell cycle progression, apoptosis, angiogenesis, and cellular transformation. Myc is a potent oncoprotein that is deregulated in a wide variety of human tumors and is therefore an attractive target for novel cancer therapies. Using a cellular screening approach, we have identified low-molecular-weight compounds, Myc pathway response agents (MYRAs), that induce apoptosis in a c-Myc-dependent manner and inhibit Myc-driven cellular transformation. MYRA-A inhibits Myc transactivation and interferes with the DNA-binding activity of Myc family proteins but has no effect on the E-box-binding protein USF. In contrast, MYRA-B induces Myc-dependent apoptosis without affecting Myc transactivation or Myc/Max DNA binding. Our data show that cellular screening assays can be a powerful strategy for the identification of candidate substances that modulate the Myc pathway. These compounds can be useful tools for studying Myc function and may also be of therapeutic potential as leads for drug development.
Collapse
Affiliation(s)
- Hao Mo
- Microbiology and Tumor Biology Center, Karolinska Institutet, S-171 77 Stockholm, Sweden
| | - Marie Henriksson
- Microbiology and Tumor Biology Center, Karolinska Institutet, S-171 77 Stockholm, Sweden
- *To whom correspondence should be addressed at:
Microbiology and Tumor Biology Center, Karolinska Institutet, Box 280, S-171 77 Stockholm, Sweden. E-mail:
| |
Collapse
|
28
|
An J, Xu QZ, Sui JL, Bai B, Zhou PK. Downregulation of c-myc protein by siRNA-mediated silencing of DNA-PKcs in HeLa cells. Int J Cancer 2005; 117:531-7. [PMID: 15929110 DOI: 10.1002/ijc.21093] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
DNA-dependent protein kinase (DNA-PK) has been intensively investigated for its roles in the nonhomologous end-joining (NHEJ) pathway of DNA double-strand break repair and maintenance of genomic stability. Its catalytic subunit, DNA-PKcs, a serine/threonine protein kinase, has recently been reported to be overexpressed in various human cancers, but its significance is unclear. In our study, we synthesized 3 small interfering RNA (siRNA) oligonucleotides, which separately target the translation initiation region, catalytic motif and a sequence between the scid-mutation region and the FATC motif of DNA-PKcs; 3 stable cell lines were generated from HeLa cells transfected with these siRNA constructs, respectively. All 3 siRNAs resulted in remarkable depression on DNA-PKcs expression in HeLa cells, and led to an increased sensitivity to 2 or 4 Gy of gamma-ray as well as 5 or 10 J/m(2) of ultraviolet (UV) irradiation. The siRNA targeting the catalytic motif of DNA-PKcs exhibited the greatest efficiency of radiosensitization. We demonstrated that c-myc protein level was suppressed more than 80% by siRNA-mediated silencing of DNA-PKcs. Using an E-box enhancer (c-myc binding element) driving a secreted alkaline phosphatase (SEAP) reporter strategy, we further found that the transcriptional activity of c-myc was extremely suppressed by silencing DNA-PKcs. The highest suppression effect on c-myc expression was observed in the cells transfected with the siRNA targeting the catalytic motif of DNA-PKcs. Moreover, a similar suppression on c-myc expression and activity was also detected in HeLa cells treated with wortmannin, a phosphatidylinositol (PI)-3 kinase inhibitor. However, silencing DNA-PKcs did not change the level of c-myc mRNA. We have further identified the interaction between DNA-PKcs and c-myc protein. Together, our results imply that DNA-PKcs activity is necessary or contributory to the expression of c-myc protein. Targeting DNA-PKcs is an attractive anticancer strategy, which can achieve through at least two mechanistic pathways: (i) sensitizing cancer cells to radiotherapy or chemotherapy of DNA-damaging agents and (ii) downregulation of c-myc protein.
Collapse
Affiliation(s)
- Jing An
- Department of Radiation Toxicology and Oncology, Beijing Institute of Radiation Medicine, Peoples Republic of China
| | | | | | | | | |
Collapse
|
29
|
Sun J, Xie L, Wang Y, Liu T. Inhibition of human lens epithelial B-3 cell proliferation by adenovirus-mediated transfer of antisense c-myc construct. Graefes Arch Clin Exp Ophthalmol 2005; 243:601-6. [PMID: 15672251 DOI: 10.1007/s00417-004-1095-4] [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: 08/09/2004] [Revised: 10/07/2004] [Accepted: 11/15/2004] [Indexed: 10/25/2022] Open
Abstract
PURPOSE To investigate the effects of adenovirus-mediated transfer of antisense c-myc construct on human lens epithelial B-3 (HLE B-3) cell proliferation, apoptosis and cell cycle. METHODS HLE B-3 cell cultures were transduced with replication-defective adenovirus bearing either a nuclear-targeted beta-galactosidase (Ad-lacZ) or an antisense c-myc construct (Ad-AS-myc). The presence of beta-galactosidase activity in the transduced cultures was detected by immunohistochemical X-Gal staining, while c-myc mRNA and protein expression levels were evaluated by RT-PCR and Western blot analysis. HLE B-3 cell proliferation within 96 h after the transduction was analyzed by cell counting and MTT colorimetric assay. Apoptosis and cell cycle of the HLE-B3 cells were examined by flow-cytometric analysis. RESULTS The mean transduction efficiency was 80% for HLE B-3 cells. Downregulation of c-myc mRNA and protein expression was noticed at 48, 96 and 144 h after the transduction with Ad-AS-myc. Cytostatic effects of Ad-AS-myc in HLE B-3 cells were obvious within 96 h after the transduction. An increased incidence of apoptosis and G1-phase arrest was identified in the Ad-AS-myc-transduced HLE B-3 cells. CONCLUSIONS HLE B-3 cells were successfully transduced with adenovirus-mediated antisense c-myc construct. Ad-AS-myc transduction could significantly inhibit cell proliferation and induce cell apoptosis and G1-phase arrest in HLE B-3 cells. It may provide a novel approach for prevention of posterior capsular opacification.
Collapse
Affiliation(s)
- Jie Sun
- Shandong Eye Institute & Hospital, 5 Yanerdao Road, Qingdao, 266071, People's Republic of China
| | | | | | | |
Collapse
|
30
|
Taniguchi I, Hata H, Sonoki T. Down-regulation of Cyclin D3 by Small-interfering RNA Induces Cell Cycle Arrest and Apoptosis through the Dissociation of p27Kip1 in a t(6; 14) (p21; q32) Positive Myeloma Cell Line. J Clin Exp Hematop 2005. [DOI: 10.3960/jslrt.45.81] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
|
31
|
Boxer RB, Jang JW, Sintasath L, Chodosh LA. Lack of sustained regression of c-MYC-induced mammary adenocarcinomas following brief or prolonged MYC inactivation. Cancer Cell 2004; 6:577-86. [PMID: 15607962 DOI: 10.1016/j.ccr.2004.10.013] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2004] [Revised: 09/03/2004] [Accepted: 10/05/2004] [Indexed: 11/15/2022]
Abstract
Recent studies of oncogene dependence in conditional transgenic mice have suggested the exciting possibility that transient or prolonged MYC inactivation may be sufficient for sustained reversal of the tumorigenic process. In contrast, we report here that following oncogene downregulation, the majority of c-MYC-induced mammary adenocarcinomas grow in the absence of MYC overexpression. In addition, residual neoplastic cells persist from virtually all tumors that do regress to a nonpalpable state and these residual cells rapidly recover their malignant properties following MYC reactivation or spontaneously recur in a MYC-independent manner. Thus, MYC-induced mammary tumor cells subjected to either brief or prolonged MYC inactivation remain exquisitely sensitive to its oncogenic effects and characteristically progress to a state in which growth is MYC-independent.
Collapse
Affiliation(s)
- Robert B Boxer
- Department of Cancer Biology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | | | | | | |
Collapse
|