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Synergistic Effect of Erastin Combined with Nutlin-3 on Vestibular Schwannoma Cells as p53 Modulates Erastin-Induced Ferroptosis Response. JOURNAL OF ONCOLOGY 2022; 2022:7507857. [PMID: 35359340 PMCID: PMC8961447 DOI: 10.1155/2022/7507857] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 03/01/2022] [Accepted: 03/04/2022] [Indexed: 12/18/2022]
Abstract
Vestibular schwannoma (VS) is a rare neurotology neoplasm that results in partial neurological defects. As we know, a comprehensive understanding of basic mechanisms and targeted therapy is vital for disease management. In VS, p53 has been proved to suppress tumor progression via a cooperative with the key protein, merlin, as well as regulation of the cell cycle. However, there are more potential mechanisms of p53 in VS needed to exploit. First, via genome-wide RNA expression analysis, we identified differentially expressed genes in VS compared with normal nerves, and then, bioinformatics analyses were used to analyze these differential expression data and suggested a high level of enrichment of cysteine and glutathione metabolism pathways in VS. Meanwhile, we observed a downregulation of SLC7A11/xCT, a component of the cystine/glutamate antiporter (also known as system xc−) involved in cystine uptake. Next, for a deeper study, our group extracted tumor cells from vestibular schwannoma tissues and established two immortalized cell lines named JEI-001 and JEI-002. Secondly, in our established cells, we demonstrated that ferroptosis participated in erastin-induced growth inhibition. As a novel cell death process, ferroptosis driven by iron-mediated lipid reactive oxygen species (lipid ROS), as well as cysteine and glutathione metabolism. Furthermore, ferroptosis contributes to the inhibitory effects of tumor suppressor p53. Here, we show that p53 sensitizes schwannoma cells to ferroptosis by repressing expression of SLC7A11/xCT. Finally, erastin combined with Nutlin-3, which s to p53 activation, triggered antitumor effects of ferroptosis on the growth of schwannoma cells in vitro. These findings present potential mechanism of p53 in schwannomas and raise the possibility of treatment strategies directed against this pathogenesis.
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Zanoletti E, Mazzoni A, Martini A, Abbritti RV, Albertini R, Alexandre E, Baro V, Bartolini S, Bernardeschi D, Bivona R, Bonali M, Borghesi I, Borsetto D, Bovo R, Breun M, Calbucci F, Carlson ML, Caruso A, Cayé-Thomasen P, Cazzador D, Champagne PO, Colangeli R, Conte G, D'Avella D, Danesi G, Deantonio L, Denaro L, Di Berardino F, Draghi R, Ebner FH, Favaretto N, Ferri G, Fioravanti A, Froelich S, Giannuzzi A, Girasoli L, Grossardt BR, Guidi M, Hagen R, Hanakita S, Hardy DG, Iglesias VC, Jefferies S, Jia H, Kalamarides M, Kanaan IN, Krengli M, Landi A, Lauda L, Lepera D, Lieber S, Lloyd SLK, Lovato A, Maccarrone F, Macfarlane R, Magnan J, Magnoni L, Marchioni D, Marinelli JP, Marioni G, Mastronardi V, Matthies C, Moffat DA, Munari S, Nardone M, Pareschi R, Pavone C, Piccirillo E, Piras G, Presutti L, Restivo G, Reznitsky M, Roca E, Russo A, Sanna M, Sartori L, Scheich M, Shehata-Dieler W, Soloperto D, Sorrentino F, Sterkers O, Taibah A, Tatagiba M, Tealdo G, Vlad D, Wu H, Zanetti D. Surgery of the lateral skull base: a 50-year endeavour. ACTA OTORHINOLARYNGOLOGICA ITALICA : ORGANO UFFICIALE DELLA SOCIETA ITALIANA DI OTORINOLARINGOLOGIA E CHIRURGIA CERVICO-FACCIALE 2019; 39:S1-S146. [PMID: 31130732 PMCID: PMC6540636 DOI: 10.14639/0392-100x-suppl.1-39-2019] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Disregarding the widely used division of skull base into anterior and lateral, since the skull base should be conceived as a single anatomic structure, it was to our convenience to group all those approaches that run from the antero-lateral, pure lateral and postero-lateral side of the skull base as “Surgery of the lateral skull base”. “50 years of endeavour” points to the great effort which has been made over the last decades, when more and more difficult surgeries were performed by reducing morbidity. The principle of lateral skull base surgery, “remove skull base bone to approach the base itself and the adjacent sites of the endo-esocranium”, was then combined with function preservation and with tailoring surgery to the pathology. The concept that histology dictates the extent of resection, balancing the intrinsic morbidity of each approach was the object of the first section of the present report. The main surgical approaches were described in the second section and were conceived not as a step-by-step description of technique, but as the highlighthening of the surgical principles. The third section was centered on open issues related to the tumor and its treatment. The topic of vestibular schwannoma was investigated with the current debate on observation, hearing preservation surgery, hearing rehabilitation, radiotherapy and the recent efforts to detect biological markers able to predict tumor growth. Jugular foramen paragangliomas were treated in the frame of radical or partial surgery, radiotherapy, partial “tailored” surgery and observation. Surgery on meningioma was debated from the point of view of the neurosurgeon and of the otologist. Endolymphatic sac tumors and malignant tumors of the external auditory canal were also treated, as well as chordomas, chondrosarcomas and petrous bone cholesteatomas. Finally, the fourth section focused on free-choice topics which were assigned to aknowledged experts. The aim of this work was attempting to report the state of the art of the lateral skull base surgery after 50 years of hard work and, above all, to raise questions on those issues which still need an answer, as to allow progress in knowledge through sharing of various experiences. At the end of the reading, if more doubts remain rather than certainties, the aim of this work will probably be achieved.
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Affiliation(s)
- E Zanoletti
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - A Mazzoni
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - A Martini
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - R V Abbritti
- Department of Neurosurgery, Lariboisière Hospital, University of Paris Diderot, Paris, France
| | | | - E Alexandre
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - V Baro
- Academic Neurosurgery, Department of Neuroscience DNS, University of Padova Medical School, Padova, Italy
| | - S Bartolini
- Neurosurgery, Bellaria Hospital, Bologna, Italy
| | - D Bernardeschi
- AP-HP, Groupe Hôspital-Universitaire Pitié-Salpêtrière, Neuro-Sensory Surgical Department and NF2 Rare Disease Centre, Paris, France
- Sorbonne Université, Paris, France
| | - R Bivona
- ENT and Skull-Base Surgery Department, Department of Neurosciences, Ospedale Papa Giovanni XXIII, Bergamo, Italy
| | - M Bonali
- Otolaryngology-Head and Neck Surgery Department, University Hospital of Modena, Italy
| | - I Borghesi
- Neurosurgery, Maria Cecilia Hospital, Cotignola (RA), Italy
| | - D Borsetto
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - R Bovo
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - M Breun
- Department of Neurosurgery, Julius Maximilians University Hospital Würzburg, Bavaria, Germany
| | - F Calbucci
- Neurosurgery, Maria Cecilia Hospital, Cotignola (RA), Italy
| | - M L Carlson
- Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic, Rochester, MN, USA
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA
| | - A Caruso
- Gruppo Otologico, Piacenza-Rome, Italy
| | - P Cayé-Thomasen
- The Department of Otorhinolaryngology, Head & Neck Surgery and Audiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - D Cazzador
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
- Department of Neuroscience DNS, Section of Human Anatomy, Padova University, Padova, Italy
| | - P-O Champagne
- Department of Neurosurgery, Lariboisière Hospital, University of Paris Diderot, Paris, France
| | - R Colangeli
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - G Conte
- Department of Neuroradiology, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milano, Italy
| | - D D'Avella
- Academic Neurosurgery, Department of Neuroscience DNS, University of Padova Medical School, Padova, Italy
| | - G Danesi
- ENT and Skull-Base Surgery Department, Department of Neurosciences, Ospedale Papa Giovanni XXIII, Bergamo, Italy
| | - L Deantonio
- Department of Radiation Oncology, University Hospital Maggiore della Carità, Novara, Italy
- Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy
| | - L Denaro
- Academic Neurosurgery, Department of Neuroscience DNS, University of Padova Medical School, Padova, Italy
| | - F Di Berardino
- Unit of Audiology, Department of Clinical Sciences and Community Health, University of Milano, Italy
- Department of Surgery, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milano, Italy
| | - R Draghi
- Neurosurgery, Maria Cecilia Hospital, Cotignola (RA), Italy
| | - F H Ebner
- Department of Neurosurgery, Eberhard Karls University Tübingen, Germany
| | - N Favaretto
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - G Ferri
- Otolaryngology-Head and Neck Surgery Department, University Hospital of Modena, Italy
| | | | - S Froelich
- Department of Neurosurgery, Lariboisière Hospital, University of Paris Diderot, Paris, France
| | | | - L Girasoli
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - B R Grossardt
- Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA
| | - M Guidi
- Gruppo Otologico, Piacenza-Rome, Italy
| | - R Hagen
- Department of Otorhinolaryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery, "Julius-Maximilians" University Hospital of Würzburg, Bavaria, Germany
| | - S Hanakita
- Department of Neurosurgery, Lariboisière Hospital, University of Paris Diderot, Paris, France
| | - D G Hardy
- Department of Neurosurgery, Cambridge University Hospital, Cambridge, UK
| | - V C Iglesias
- ENT and Skull-Base Surgery Department, Department of Neurosciences, Ospedale Papa Giovanni XXIII, Bergamo, Italy
| | - S Jefferies
- Oncology Department, Cambridge University Hospital, Cambridge, UK
| | - H Jia
- Department of Otolaryngology Head and Neck Surgery, Shanghai Ninh People's Hospital, Shanghai Jiatong University School of Medicine, China
| | - M Kalamarides
- AP-HP, Groupe Hôspital-Universitaire Pitié-Salpêtrière, Neuro-Sensory Surgical Department and NF2 Rare Disease Centre, Paris, France
- Sorbonne Université, Paris, France
| | - I N Kanaan
- Department of Neurosciences, King Faisal Specialist Hospital & Research Center, Alfaisal University, College of Medicine, Riyadh, KSA
| | - M Krengli
- Department of Radiation Oncology, University Hospital Maggiore della Carità, Novara, Italy
- Department of Translational Medicine, University of Piemonte Orientale, Novara, Italy
| | - A Landi
- Academic Neurosurgery, Department of Neuroscience DNS, University of Padova Medical School, Padova, Italy
| | - L Lauda
- Gruppo Otologico, Piacenza-Rome, Italy
| | - D Lepera
- ENT & Skull-Base Department, Ospedale Nuovo di Legnano, Legnano (MI), Italy
| | - S Lieber
- Department of Neurosurgery, Eberhard Karls University Tübingen, Germany
| | - S L K Lloyd
- Department of Neuro-Otology and Skull-Base Surgery Manchester Royal Infirmary, Manchester, UK
| | - A Lovato
- Department of Neuroscience DNS, Audiology Unit, Padova University, Treviso, Italy
| | - F Maccarrone
- Otolaryngology-Head and Neck Surgery Department, University Hospital of Modena, Italy
| | - R Macfarlane
- Department of Neurosurgery, Cambridge University Hospital, Cambridge, UK
| | - J Magnan
- University Aix-Marseille, France
| | - L Magnoni
- Unit of Audiology, Department of Clinical Sciences and Community Health, University of Milano, Italy
- Department of Surgery, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milano, Italy
| | - D Marchioni
- Otolaryngology-Head and Neck Surgery Department, University Hospital of Verona, Italy
| | | | - G Marioni
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | | | - C Matthies
- Department of Neurosurgery, Julius Maximilians University Hospital Würzburg, Bavaria, Germany
| | - D A Moffat
- Department of Neuro-otology and Skull Base Surgery, Cambridge University Hospital, Cambridge, UK
| | - S Munari
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - M Nardone
- ENT Department, Treviglio (BG), Italy
| | - R Pareschi
- ENT & Skull-Base Department, Ospedale Nuovo di Legnano, Legnano (MI), Italy
| | - C Pavone
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | | | - G Piras
- Gruppo Otologico, Piacenza-Rome, Italy
| | - L Presutti
- Otolaryngology-Head and Neck Surgery Department, University Hospital of Modena, Italy
| | - G Restivo
- ENT and Skull-Base Surgery Department, Department of Neurosciences, Ospedale Papa Giovanni XXIII, Bergamo, Italy
| | - M Reznitsky
- The Department of Otorhinolaryngology, Head & Neck Surgery and Audiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - E Roca
- Department of Neurosurgery, Lariboisière Hospital, University of Paris Diderot, Paris, France
| | - A Russo
- Gruppo Otologico, Piacenza-Rome, Italy
| | - M Sanna
- Gruppo Otologico, Piacenza-Rome, Italy
| | - L Sartori
- Academic Neurosurgery, Department of Neuroscience DNS, University of Padova Medical School, Padova, Italy
| | - M Scheich
- Department of Otorhinolaryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery, "Julius-Maximilians" University Hospital of Würzburg, Bavaria, Germany
| | - W Shehata-Dieler
- Department of Otorhinolaryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery, "Julius-Maximilians" University Hospital of Würzburg, Bavaria, Germany
| | - D Soloperto
- Otolaryngology-Head and Neck Surgery Department, University Hospital of Verona, Italy
| | - F Sorrentino
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - O Sterkers
- AP-HP, Groupe Hôspital-Universitaire Pitié-Salpêtrière, Neuro-Sensory Surgical Department and NF2 Rare Disease Centre, Paris, France
- Sorbonne Université, Paris, France
| | - A Taibah
- Gruppo Otologico, Piacenza-Rome, Italy
| | - M Tatagiba
- Department of Neurosurgery, Eberhard Karls University Tübingen, Germany
| | - G Tealdo
- Department of Neuroscience DNS, Otolaryngology Section, Padova University, Padova, Italy
| | - D Vlad
- Gruppo Otologico, Piacenza-Rome, Italy
| | - H Wu
- Department of Otolaryngology Head and Neck Surgery, Shanghai Ninh People's Hospital, Shanghai Jiatong University School of Medicine, China
| | - D Zanetti
- Unit of Audiology, Department of Clinical Sciences and Community Health, University of Milano, Italy
- Department of Surgery, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milano, Italy
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Chen H, Xue L, Huang H, Wang H, Zhang X, Zhu W, Wang Z, Wang Z, Wu H. Synergistic effect of Nutlin-3 combined with MG-132 on schwannoma cells through restoration of merlin and p53 tumour suppressors. EBioMedicine 2018; 36:252-265. [PMID: 30274821 PMCID: PMC6197711 DOI: 10.1016/j.ebiom.2018.09.042] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 09/14/2018] [Accepted: 09/24/2018] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND The great majority of sporadic vestibular schwannomas (VSs) are due to the mutations of the NF2 gene encoding merlin. Sporadic VSs exhibit variable growth patterns and only a small fraction of the tumours are fast-growing; however, the underlying mechanisms remain undefined. METHODS DNA sequencing and dosage analysis were used to identify the NF2 mutation status in sporadic schwannomas. The expression and sub-cellular localization of merlin and p53-MDM2 were assessed by immunoblotting, qRT-PCR and immunofluorescence. In vitro and in vivo studies were performed to reveal the effects of Nutlin-3 (a MDM2 inhibitor) and/or MG-132(a proteasome inhibitor) on schwannomas. The proliferation of schwannoma cells was assessed by CCK-8 assay, EdU staining and Flow cytometry analysis. FINDINGS Double genetic hits of NF2 tended to occur in fast-growing tumours, characterized by the absence of merlin. The deregulation of p53-MDM2 was demonstrated to mediate merlin-deficient tumour growth, characterized by a nuclear accumulation of stabilized MDM2, contributing to a nuclear export of p53 for degradation. Nutlin-3 blocked the proliferation of schwannoma cells via a cooperative recovery of merlin and p53, accompanied by the shuttling of both proteins from the cytoplasm to the nucleus. We further demonstrated a difference in the sensitivity to Nutlin-3 between schwannoma cells with and without merlin expression. Nutlin-3 combined with MG-132 narrowed this between-group difference and triggered stronger inhibitory effects on the growth of schwannomas through coordinated reactivation of p53. INTERPRETATION These findings present treatment strategies directed on the pathogenesis of sporadic schwannomas. FUND: National Natural Science Foundation of China.
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Affiliation(s)
- Hongsai Chen
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China; Shanghai Institute of Precision Medicine, The Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Lu Xue
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - He Huang
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Hantao Wang
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Xiaoman Zhang
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Weidong Zhu
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Zhigang Wang
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Zhaoyan Wang
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
| | - Hao Wu
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
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Chen H, Xue L, Wang H, Wang Z, Wu H. Differential NF2 Gene Status in Sporadic Vestibular Schwannomas and its Prognostic Impact on Tumour Growth Patterns. Sci Rep 2017. [PMID: 28710469 DOI: 10.1038/srep5470] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023] Open
Abstract
The great majority of sporadic vestibular schwannomas (VSs) are due to the inactivation of the NF2 gene. In this study, we found age-dependent differences in the clinical parameters of sporadic VSs. Young patients were characterized by progressive tumour behaviours, including earlier onset of initial symptoms, shorter symptom duration and larger tumour size. An increased rate of "two-hits" of both NF2 alleles, usually by mutation and allelic loss, was observed in young cases compared to older, and this correlated with the loss of protein and mRNA expression. In contrast, the tumours with a single mutation (referred to as 'one-hit') exhibited obvious expression levels. Moreover, a mixture of merlin-expressing tumour cells and non-expressing tumour cells was observed in 'one-hit' schwannomas, suggesting that a subset of 'one-hit' tumour cells was present in these tumours. To mimic the growth promoting effects by the second hit, we performed lentivirus-mediated NF2 knockdown in the 'one-hit' schwannoma cultures. Following the loss of NF2 expression, schwannoma cultures demonstrated increased proliferation rates. Above all, we have identified a correlation between the NF2 status and the growth patterns of sporadic VSs. The treatment decision-making, microsurgery or "wait and scan" strategy, should be carried out according to the tumour's genetic background.
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Affiliation(s)
- Hongsai Chen
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Lu Xue
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Hantao Wang
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Zhaoyan Wang
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
- Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
| | - Hao Wu
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
- Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
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Chen H, Xue L, Wang H, Wang Z, Wu H. Differential NF2 Gene Status in Sporadic Vestibular Schwannomas and its Prognostic Impact on Tumour Growth Patterns. Sci Rep 2017; 7:5470. [PMID: 28710469 PMCID: PMC5511254 DOI: 10.1038/s41598-017-05769-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 06/02/2017] [Indexed: 02/06/2023] Open
Abstract
The great majority of sporadic vestibular schwannomas (VSs) are due to the inactivation of the NF2 gene. In this study, we found age-dependent differences in the clinical parameters of sporadic VSs. Young patients were characterized by progressive tumour behaviours, including earlier onset of initial symptoms, shorter symptom duration and larger tumour size. An increased rate of “two-hits” of both NF2 alleles, usually by mutation and allelic loss, was observed in young cases compared to older, and this correlated with the loss of protein and mRNA expression. In contrast, the tumours with a single mutation (referred to as ‘one-hit’) exhibited obvious expression levels. Moreover, a mixture of merlin-expressing tumour cells and non-expressing tumour cells was observed in ‘one-hit’ schwannomas, suggesting that a subset of ‘one-hit’ tumour cells was present in these tumours. To mimic the growth promoting effects by the second hit, we performed lentivirus-mediated NF2 knockdown in the ‘one-hit’ schwannoma cultures. Following the loss of NF2 expression, schwannoma cultures demonstrated increased proliferation rates. Above all, we have identified a correlation between the NF2 status and the growth patterns of sporadic VSs. The treatment decision-making, microsurgery or “wait and scan” strategy, should be carried out according to the tumour’s genetic background.
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Affiliation(s)
- Hongsai Chen
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Lu Xue
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Hantao Wang
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Zhaoyan Wang
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. .,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China. .,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
| | - Hao Wu
- Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. .,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China. .,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
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Li X, Chen H, Xue L, Pang X, Zhang X, Zhu Z, Zhu W, Wang Z, Wu H. p53 performs an essential role in mediating the oncogenic stimulus triggered by loss of expression of neurofibromatosis type 2 during in vitro tumor progression. Oncol Lett 2017; 14:2223-2231. [PMID: 28789444 PMCID: PMC5530008 DOI: 10.3892/ol.2017.6445] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 03/10/2017] [Indexed: 02/04/2023] Open
Abstract
The loss of the tumor suppressor neurofibromatosis type 2 gene, encoding merlin, has been considered to be a fundamental event during the malignant progression of various cell types. However, a consensus for the mainstream mechanism, by which merlin deficiency contributes to uncontrolled cellular proliferation, has not been reached. The present study aimed to determine whether silencing of merlin using lentivirus-based short hairpin RNA potentiates cellular proliferation and cell cycle progression in human colon carcinoma HCT116 cell lines, expressing p53. The present results demonstrated that merlin knockdown contributed to cellular proliferation and G1/S cell cycle progression to a greater extent in HCT116 cells wide-type for p53 (p53wt) compared with p53-null (p53−/−) cells. This was supported by overexpression experiments which demonstrated a significant inhibitory effect of excess merlin on cellular proliferation only in HCT116 p53wt cells. In order to investigate the underlying mechanisms of action, the expression of p53-involved G1/S transition genes was evaluated by western blot analysis. For HCT116 p53wt cells, merlin loss suppressed p53 expression, and therefore the dysregulation of cell cycle regulatory proteins, including p21, cyclin D1/cyclin-dependent kinase (CDK)4 and cyclin E1/CDK2 complexes. However, merlin knockdowns had no impact on the expression of any of the aforementioned molecules in p53−/− cells, indicating that lack of merlin resulted in G1/S cell cycle progression, and thereby uncontrolled cellular proliferation mainly via the regulation of p53-mediated pathways. Taken together, it was proposed that p53 performs an essential role in mediating the oncogenic stimulus triggered by merlin loss, and p53 is a molecule that should be investigated for its potential in targeted drug therapy for merlin-deficient malignancies.
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Affiliation(s)
- Xiye Li
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, P.R. China
| | - Hongsai Chen
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, P.R. China
| | - Lu Xue
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, P.R. China
| | - Xiuhong Pang
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, P.R. China
| | - Xiaoman Zhang
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, P.R. China
| | - Zhengjie Zhu
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, P.R. China
| | - Weidong Zhu
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, P.R. China
| | - Zhaoyan Wang
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, P.R. China
| | - Hao Wu
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200092, P.R. China
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Role of cyclins D1 and D3 in vestibular schwannoma. The Journal of Laryngology & Otology 2015; 130 Suppl 1:S2-10. [PMID: 26165351 DOI: 10.1017/s0022215115001735] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Vestibular schwannomas in younger patients have been observed to be larger in size and grow more quickly. OBJECTIVE This study aimed to evaluate the expression of three important cell cycle proteins, cyclin D1, cyclin D3 and Ki-67, in vestibular schwannoma patients separated into two age groups: ≤ 40 years or > 40 years. METHOD Immunohistochemical detection of cyclin D1, cyclin D3 and Ki-67 was undertaken in 180 surgically resected vestibular schwannomas. RESULTS The proliferation index of vestibular schwannomas was statistically higher in the ≤ 40 years age group compared to that in the > 40 years age group (mean of 4.52 vs 3.27, respectively; p = 0.01). Overexpression of cyclin D1 and cyclin D3 was found in 68 per cent and 44 per cent of tumours, respectively. CONCLUSION There was an increased Ki-67 proliferation index in the younger age group that appears to correlate with clinical behaviour. Vestibular schwannomas in both age groups show increased expression of cyclin D1 and cyclin D3.
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P14ARF deficiency and its correlation with overexpression of p53/MDM2 in sporadic vestibular schwannomas. Eur Arch Otorhinolaryngol 2014; 272:2227-34. [PMID: 24964769 DOI: 10.1007/s00405-014-3135-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 06/03/2014] [Indexed: 10/25/2022]
Abstract
Recent studies have shed considerable light into schwannomas. To date, only merlin has been identified as a hallmark or pathogenesis of both sporadic and NF2-related schwannomas. Here, we show, by immunoblot and immunohistochemical analyses of 58 sporadic vestibular schwannomas, that upregulation of p53 was observed in 90 % of tumors examined. No p53 mutations were found in 12 % tumors analyzed. Expression of p14ARF was negative in 95 % of tumors, while overexpression of MDM2 was found in all specimens. Aberrant DNA hypermethylation of the p14ARF promoter was observed in three of seven tumors examined (43 %), associated with remarkably decreased mRNA levels. The very high degree of concordance in the aberrations of the p14ARF/MDM2/p53 pathway in this tumor may be considered to be a new player in the pathogenesis of sporadic vestibular schwannomas. Moreover, expression of p21 (waf1) was negative in all tumors, suggesting that the aberration of this pathway is associated with greater attenuation of p21-mediated signals that are critical for growth inhibition. These data are in agreement with the model in RT-4 rat schwannoma cells: i.e., overexpression of ARF was associated with accumulation of p21 expression both at protein and mRNA levels. ShRNA knock-down of p53 expression attenuated p21-mediated increase in cellular arrest in the G1-phase, suggesting that p14ARF regulates p21 protein levels through a p53-dependent pathway. Thus, this study reveals a high degree of concordance in the aberrations of the p14ARF/MDM2/p53 pathway with the development of sporadic vestibular schwannomas.
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Chen H, Zhang X, Zhang Z, Yang T, Wang Z, Wu H. The role of NF2 gene mutations and pathogenesis-related proteins in sporadic vestibular schwannomas in young individuals. Mol Cell Biochem 2014; 392:145-52. [PMID: 24619252 DOI: 10.1007/s11010-014-2011-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Accepted: 01/29/2014] [Indexed: 10/25/2022]
Abstract
Vestibular schwannomas (VSs) are benign tumors arising from eighth cranial nerve and most often occur sporadically in individuals of middle age group. Sporadic VSs are rarely reported in the young population. In this study, we evaluated clinical behaviors of 12 young sporadic VSs by the statistical comparison with a matched series of 145 adult cases. We found that young tumors were characterized by an earlier onset of initial symptom, shorter duration from the first symptom to diagnosis, and larger tumor size than adult ones. Standard sequencing demonstrated the presence of NF2 mutations in eight tumors. All NF2 mutations identified were truncating mutations (nonsense, frameshift, and splicing-site mutations). Earlier formation of VSs in young patients was evidenced by the high incidence of NF2 mutations (66.7%) far beyond our previous study in the adult case series (34.5%). Furthermore, young tumors exhibited deficient merlin or heightened phosphorylated merlin that was subsequently demonstrated to be well correlated with increased tumor size. Finally, we compared protein levels of four pathogenesis-related molecules between young and adult group but there was no significant difference. These results led us to suggest that high frequency of NF2 mutations may play a critical role in early tumorigenesis of young VSs. Moreover, merlin deficiency or phosphorylation status of merlin was involved in their earlier development. Further study remains to fully understand the mechanism for the rapid growth of young VSs.
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Affiliation(s)
- Hongsai Chen
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, 1665 Kongjiang Road, Shanghai, 200092, China
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Mitra R, Bhagavatula ID, Gope R. BAY 61-3606, CDKi, and sodium butyrate treatments alter gene expression in human vestibular schwannomas and cause cell death in vitro. Ecancermedicalscience 2013; 6:285. [PMID: 23304241 PMCID: PMC3530378 DOI: 10.3332/ecancer.2012.285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Indexed: 11/24/2022] Open
Abstract
Background: Disrupted kinase and signaling pathways are found in many human cancers and they are implicated in carcinogenesis. Therefore, kinases have been important targets for the development of cancer therapeutics. Human vestibular schwannomas (VS) are the third most common intracranial tumours which occur in the vestibular branch of VIIIth cranial nerve. Sodium butyrate (Na-Bu) is a potent histone deacetylase inhibitor (HDACi) and with therapeutic efficacy. Spleen tyrosine kinase (Syk) has been implicated in many immunological consequences and is a putative target for cancer treatment. Aims and objectives: The present study was undertaken in order to evaluate the effect Na-Bu, 2,4-Diamino-5-oxo-pyrimidine hydrochloride (CDKi), a broad spectrum kinase inhibitor and BAY 61-3606 (Syk inhibitor) on the survival of VS tumour tissues in vitro and their possible effects on cell survival/death and levels of a few key proteins in the treated cells as compared to the untreated cells. Materials and methods Fresh tumour tissues were collected randomly from 16 patients with sporadic, VS tumours, minced into pieces and maintained in primary cultures. Twenty four hours later these cells were exposed to Na-Bu, BAY 61-3606 or CDKi. Forty eight hours after exposure, the tissue lysates were analysed by western blotting for expression of pRb and other proteins involved in cell survival/death. Summary and significance of the findings: The tissue samples used were positive for S100A protein, the maker for schwann cells confirming the VS tumour samples. The three individual treatments led to morphological change, DNA fragmentation and cell death and significantly reduced level of total and phosphorylated forms of pRb protein and drastically reduced EGF-R protein. These treatments also modulated levels of other proteins involved in cell survival/death such as PI3K, Caspase 3, TGF-β1, JNK, ASK1, Shh, NF-κB, p21cip1/waf1. The Untreated cells had uncleaved PARP-1 protein and the treated cells had cleaved PARP-1. The results show that the observed cell death in treated cells perhaps is mediated by modulation of the levels and processing of certain key proteins. The possible development of these components as therapeutics is discussed.
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Affiliation(s)
- Rohan Mitra
- Department of Human Genetics, NIMHANS, 2900 Hosur road, Bangalore 560029, India
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Zhou Y, Li G, Ji Y, Liu C, Zhu J, Lu Y. Cytoplasmic p21 induced by p65 prevents doxorubicin-induced cell death in pancreatic carcinoma cell line. J Biomed Sci 2012; 19:15. [PMID: 22305266 PMCID: PMC3298465 DOI: 10.1186/1423-0127-19-15] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Accepted: 02/04/2012] [Indexed: 12/29/2022] Open
Abstract
Background Studies have shown the existence of p21 induction in a p53-dependent and -independent pathway. Our previous study indicates that DOX-induced p65 is able to bind the p21 promoter to activate its transactivation in the cells. Methods Over-expression and knock-down experiments were performed in Human Pancreatic Carcinoma (PANC1) cells. Cell cycle and cell death related proteins were assessed by Western Blotting. Cytotoxicity assay was checked by CCK-8 kit. Cell growth was analyzed by flow cytometers. Results Here we showed that over-expression of p65 decreased the cytotoxic effect of DOX on PANC1 cells, correlating with increased induction of cytoplasmic p21. We observed that pro-caspase-3 physically associated with cytoplasmic p21, which may be contribution to prevent p21 translocation into the nucleus. Our data also suggested that no clear elevation of nuclear p21 by p65 provides a survival advantage by progression cell cycle after treatment of DOX. Likewise, down-regulation of p65 expression enhanced the cytotoxic effect of DOX, due to a significant decrease of mRNA levels of anti-apoptotic genes, such as the cellular inhibitor of apoptosis-1 (c-IAP1), and the long isoform of B cell leukemia/lymphoma-2 (Bcl-2), leading to efficient induction of caspase-3 cleavage in the cells. More, we present evidence that over-expression of p53 or p53/p65 in the PANC1 cells were more sensitive to DOX treatment, correlated with activation of caspase-3 and clear elevation of nuclear p21 level. Our previous data suggested that expression of p21 increases Gefitinib-induced cell death by blocking the cell cycle at the G1 and G2 phases. The present findings here reinforced this idea by showing p21's ability of potentiality of DOX-induced cell death correlated with its inhibition of cell cycle progression after over-expression of p53 or p53/p65. Conclusion Our data suggested p65 could increase p53-mediated cell death in response to DOX in PANC1 cells. Thus, it is worth noting that in p53 null or defective tumors, targeting in down-regulation of p65 may well be useful, leading to the potentiality of chemotherapeutic drugs.
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Affiliation(s)
- YingQi Zhou
- Tongji University School of Medicine, Shanghai, China
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Li G, Ji Y, Liu C, Li J, Zhou Y. Reduced levels of p15INK4b, p16INK4a, p21cip1 and p27kip1 in pancreatic carcinoma. Mol Med Rep 2012; 5:1106-10. [PMID: 22293850 PMCID: PMC3493078 DOI: 10.3892/mmr.2012.771] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 01/10/2012] [Indexed: 12/15/2022] Open
Abstract
Pancreatic carcinoma is one of the leading causes of cancer mortality worldwide, although the molecular mechanisms of this disease are poorly understood. The aim of this study was to examine the expression of cyclin-dependent kinase inhibitors (CDKIs) and the epigenetic modifications in the promoters of these genes. We also evaluated the correlation between the methylation status of CDKI genes and smoking habit in clinical pancreatic carcinoma specimens. Western blotting and real-time PCR were performed to assess CDKI expression. Methylation-specific PCR was carried out to examine the methylation status of the promoters of CDKI genes. In this study, we revealed that reduced levels of the CDKI proteins, p15INK4b, p16INK4a, p21cip1 and p27kip1, are a prominent feature of pancreatic carcinoma patients. The DNA hypermethylation of the promoter was observed in 40% (2 of 5) of the p15INK4b genes, 60% (3 of 5) of the p16INK4a genes and 60% of the p21cip1 genes, which markedly correlated with their decreased mRNA expression. No hypermethylation was detected in the p27kip1 gene promoter in 5 pancreatic carcinoma patients with markedly decreased expression of p27kip1 mRNA, suggesting an alternative mechanism of p27kip in these patients. In this study, patients with a smoking habit displayed methylation of 2 CDKI genes in their pancreatic carcinoma specimens. We concluded that epigenetic modification via hypermethylation represents a critical mechanism for the inactivation of CDKI genes in pancreatic carcinoma.
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Affiliation(s)
- Gang Li
- The Third General Surgery Department, Zhanghai Hospital, Second Military Medical University, Shanghai, PR China
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