Publications by authors named "Hongsai Chen"

12 Publications

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High throughput proteomic and metabolic profiling identified target correction of metabolic abnormalities as a novel therapeutic approach in head and neck paraganglioma.

Transl Oncol 2021 Aug 9;14(8):101146. Epub 2021 Jun 9.

Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University, School of Medicine, No. 639, Zhi-Zao-Ju Road, Shanghai 200011, 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. Electronic address:

Head and neck paragangliomas (HNPGLs) are rare neoplasms that represent difficult treatment paradigms in neurotology. Germline mutations in genes encoding succinate dehydrogenase (SDH) are the cause of nearly all familial HNPGLs. However, the molecular mechanisms underlying tumorigenesis remain unclear. Mutational analysis identified 6 out of 14 HNPGLs harboring clinicopathologic SDH gene mutations. The SDHB gene was most frequently mutated in these patients, and western blot showed loss of SDHB protein in tumors with SDHB mutations. The paraganglioma cell line (PGL-626) was established from a sample that harbored a missense SDHB mutation (c.649C > T). Spectrometric analysis using tandem mass tags identified 151 proteins significantly differentially expressed in HNPGLs compared with normal nerves. Bioinformatics analyses confirmed the high level of enrichment of oxidative phosphorylation and metabolism pathways in HNPGLs. The mitochondrial complex subunits NDUFA2, NDUFA10, and NDUFA4, showed the most significantly increased expression and were localized predominantly in the cytoplasm of PGL-626 cells. The mitochondrial complex I inhibitor metformin exerted dose-dependent inhibitory effects on PGL-626 cells via cooperative down-regulation of NDUFA2, 4, and 10, with a significant decrease in the levels of reactive oxygen species and mitochondrial membrane potential. Further metabolomic analysis of PGL-626 cells showed that metabolites involved in central carbon metabolism in cancer and sphingolipid signaling pathways, pantothenate and CoA biosynthesis, and tryptophan and carbon metabolism were significantly altered after metformin treatment. Thus, this study provides insights into the molecular mechanisms underlying HNPGL tumorigenesis and identifies target correction of metabolic abnormalities as a novel therapeutic approach for this disease.
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http://dx.doi.org/10.1016/j.tranon.2021.101146DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8193622PMC
August 2021

Proteomic screening identifies PML/p53 axis as a potential treatment target of facial nerve schwannomas.

Am J Transl Res 2020 15;12(8):4237-4250. Epub 2020 Aug 15.

Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine Shanghai, China.

Facial nerve schwannomas (FNS) represents one of the more difficult treatment paradigms in neurotology. The aim of this study is to investigate the molecular alterations of FNS, thus providing potential targets treatable in the tumour. We for the first time suggest that the deficiency of merlin (the product of tumour suppressor) is probably one of the key mechanisms underlying FNS tumourigenesis, although no disease-causing mutations were demonstrated in tumour samples. TMT-labeled spectrometry analysis was used to identify the proteome of FNS relative to nerve controls. Eighty-four significantly deregulated proteins were identified, among which the PML tumour suppressor showed the most significantly increased expression. The PML protein was distributed in the nucleoplasm of non-tumorous Schwann cells, whereas it was preferentially confined to the cytoplasm of FNS cultures. Overexpression of PML and p53, partner proteins positively regulating each other to trigger apoptosis, was further confirmed in FNS tissues/cultures, and this correlated with a significant decrease in the proliferation of FNS cultures in comparison to Schwann cells. It is therefore probable that PML-p53 overexpression may occur as part of protective cellular mechanisms in response to the proliferation signal mediated by loss of merlin in FNS, in accordance with the fact that the tumour is benign slow-growing. This hypothesis was supported by the finding that the p53 activator nutlin-3 could exert dose-dependent inhibitory effects on FNS cultures via a cooperative induction of PML-p53 levels. Thus, the current study may present a potential treatment target directed on the molecular mechanisms of this disease.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7476122PMC
August 2020

Degradable and Bioadhesive Alginate-Based Composites: An Effective Hemostatic Agent.

ACS Biomater Sci Eng 2019 Oct 18;5(10):5498-5505. Epub 2019 Sep 18.

Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai 200125, China.

The perfect hemostatic material should be capable of rapidly controlling substantial hemorrhaging from visceral organs, veins, and arteries. Ideally, it should be biodegradable, biocompatible, easily applied, and inexpensive. Herein, taking advantages of sodium alginate (SA), carboxymethyl chitosan (CMC), and collagen, a degradable powdery hemostatic composite (SACC) was synthesized using emulsification and cross-linking technology. The morphology and structure of SACC were determined using Fourier transform infrared spectroscopy and scanning electron microscopy (SEM). This hemostatic material exhibited a typical generic sphere shape with narrow size distribution, rough surface, and satisfactory water absorption. Using in vitro bleeding and in vivo bleeding models (rat liver injury model and rat tail amputation model), it was shown that SACC had superior hemostatic actions compared to CMC and SA. Excellent cytocompatibility was proven during cytotoxicity tests and SEM observations. Histomorphological evaluation during the wound healing process proved the superior biocompatibility of SACC in a rat liver injury model. Biodegradability of SACC was demonstrated by immunofluorescence techniques both in vitro and in vivo. In summary, we have demonstrated the enormous potential of SACC, which has excellent hemostatic activity, biodegradability, and biocompatibility properties for use in clinical hemostasis applications.
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http://dx.doi.org/10.1021/acsbiomaterials.9b01120DOI Listing
October 2019

Age-dependent copy number variations of TP53 tumour suppressor gene associated with altered phosphorylation status of p53 protein in sporadic schwannomas.

J Neurooncol 2019 Jul 2;143(3):369-379. Epub 2019 May 2.

Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, No. 639, Zhi-Zao-Ju Road, Shanghai, 200011, China.

Purpose: Point mutations of TP53 tumour suppressor are very rare in schwannomas. We aim to characterize the frequency of exonic copy-number changes of the gene in the tumour and to examine the association between TP53 alterations, phosphorylation status of p53 protein and clinical phenotypes.

Methods: The alterations of TP53 were screened by a combination of Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA) in a total of 44 vestibular schwannomas. The mutation index (MI) in a tumour was defined as the number of exons mutated/ the number of exons tested. Phosphorylation status of p53 protein was investigated by immunoblotting and immunofluorescence.

Results: MLPA analysis showed single and multi-exon deletion mutations of TP53 in 65.7% of the cases. Comparisons of clinical features between mutated and non-mutated patients established an association of TP53 mutations with progressive phenotypes, including an earlier formation and a larger tumour. In addition, there were significant correlations between MI and both patients' age and tumour size. The Ser 392 phosphorylation level of p53 varied among tumours, and correlation analysis revealed an age-dependent phosphorylation pattern. The majority of tumours with hyperphosphorylated p53 were from mutated and young patients, suggesting an association of Ser392 phosphorylation with the mutational status of TP53 involved in the acceleration of tumour growth in young individuals. Moreover, Ser 392 phosphorylation contributed to a nuclear accumulation of p53 in schwannona cultures with TP53 mutation.

Conclusions: An interplay between the mutation status of TP53, phosphorylation patterns and tumour behaviors might be established in the disease.
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http://dx.doi.org/10.1007/s11060-019-03176-1DOI Listing
July 2019

Synergistic effect of Nutlin-3 combined with MG-132 on schwannoma cells through restoration of merlin and p53 tumour suppressors.

EBioMedicine 2018 Oct 28;36:252-265. Epub 2018 Sep 28.

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. Electronic address:

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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http://dx.doi.org/10.1016/j.ebiom.2018.09.042DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6197711PMC
October 2018

Long-Term Hearing Preservation Outcomes for Small Vestibular Schwannomas: Retrosigmoid Removal Versus Observation.

Otol Neurotol 2018 02;39(2):e158-e165

Department of Otolaryngology Head and Neck Surgery, Ninth People's Hospital.

Objective: Management of small vestibular schwannomas (VSs) consists of three options: serial observation, radiosurgery, and microsurgery. The authors reported the long-term hearing outcomes after retrosigmoid tumor removal in 110 patients and hearing follow-up outcomes in 160 serial observation patients with small VSs to explore the appropriate management strategy and predictive factors of hearing preservation for small VSs.

Study Design: Retrospective study.

Setting: Tertiary referral center.

Patients: In this study, 110 patients with small VS (purely intracanalicular/cerebellopontine angle tumor ≤15 mm) during a 15-year period, from January 2001 to December 2015, were candidates for hearing preservation surgery through retrosigmoid approach, while 160 patients were candidates for serial observation. The main outcome measure was preservation of hearing under different hearing levels, assessed with the classification of American Academy of Otolaryngology-Head and Neck Surgery.

Results: Preoperative hearing levels of the 110 study patients were Class A in 49 patients, Class B in 43 patients, and Class C in 18 patients. In all surgery patients (n = 110), 97.3% (107/110) patients maintained the same level during postoperative follow-up (mean follow-up time was 49.1 ± 28.2 mo) and 86 (78.2%) had complete radiologic and audiometric data at least 4 years follow-up for review. In the 4 years follow-up surgery group (n = 86), postoperative hearing levels were Class A, B, C, and D for 22, 11, 18, and 35 patients, and postoperative rates of preservation of serviceable and useful hearing were 59.3% (51/86) and 47.1% (33/70), respectively. In serial observation group, mean follow-up time was 35.2 ± 33.1 months; mean tumor size at presentation was 8.6 ± 4.3 mm; overall mean tumor growth rate was 1.08 ± 2.3 mm/yr; serviceable hearing preservation rate of 98 patients was 54.1% (53/98) at the 5-year end point and 48.7% (37/76) at the 7-year end point.

Conclusion: Tumor removal should be the first treatment option for patients with small VSs and preserved hearing, especially for young patients with good hearing; retrosigmoid approach is an effective and safe approach for small VSs removal with excellent functional outcomes; better preoperative hearing predicted a higher rate of postoperative hearing preservation; patients without fundal extension were more likely to achieve hearing preservation than those with fundal extension, but no difference had been detected when retrosigmoid removal assisted with endoscope was performed; patients with small tumors originating from SVN were more likely to achieve hearing preservation compared with those with IVN-originating tumors.
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http://dx.doi.org/10.1097/MAO.0000000000001684DOI Listing
February 2018

p53 performs an essential role in mediating the oncogenic stimulus triggered by loss of expression of neurofibromatosis type 2 during tumor progression.

Oncol Lett 2017 Aug 21;14(2):2223-2231. Epub 2017 Jun 21.

Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, P.R. China.

The loss of the tumor suppressor 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 (p53) 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 p53 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 p53 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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http://dx.doi.org/10.3892/ol.2017.6445DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5530008PMC
August 2017

Differential NF2 Gene Status in Sporadic Vestibular Schwannomas and its Prognostic Impact on Tumour Growth Patterns.

Sci Rep 2017 07 14;7(1):5470. Epub 2017 Jul 14.

Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.

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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http://dx.doi.org/10.1038/s41598-017-05769-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5511254PMC
July 2017

Genetic and epigenetic patterns in patients with the head-and-neck paragangliomas associate with differential clinical characteristics.

J Cancer Res Clin Oncol 2017 Jun 3;143(6):953-960. Epub 2017 Mar 3.

Department of Otolaryngology Head and Neck Surgery, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, No. 639, Zhi-Zao-Ju Road, Shanghai, 200011, China.

Purpose: In addition to genetic alterations, the importance of a CpG island methylator phenotype, characterized by methylation of multiple tumour-suppressor genes (TSGs), has been acknowledged in many cancer types. This study was done to determine the impact of genetic and epigenetic patterns on the clinical characteristics of the head and neck paragangliomas (HNPGLs).

Methods: The retrospective study examined a series of 37 patients with HNPGLs who underwent surgical resection between 2010 and 2015. The mutations in the succinate dehydrogenase (SDH) genes were detected using direct DNA sequencing. Aberrant hypermethylation of the CpG islands of a panel of ten TSGs was also analysed using methylation-specific PCR.

Results: Direct sequencing demonstrated the presence of germline SDH mutations in ten HNPGLs. Comparisons of clinical features between mutated and non-mutated HNPGLs established an association of SDH mutations with progressive phenotypes, including an earlier formation, multiple lesions, or malignancy. There was also a significant correlation between the presence of SDH mutations and the number of TSGs methylated in HNPGLs. The SDH-related tumours were therefore more likely to suffer from a CpG island methylator phenotype. Four differentially methylated TSGs in mutated tumours vs non-mutated counterparts were identified with inefficient expression through Real-Time PCR analysis.

Conclusions: Our results suggested that epigenetic inactivation on multiple TSGs may serve as a key mechanism for the progressive behaviors of SDH-mutated HNPGLs. Thus, an interplay between genetic status, epigenetic alterations, and clinical features might be established in the disease.
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http://dx.doi.org/10.1007/s00432-017-2355-0DOI Listing
June 2017

A Novel Missense Mutation of NOG Interferes With the Dimerization of NOG and Causes Proximal Symphalangism Syndrome in a Chinese Family.

Ann Otol Rhinol Laryngol 2015 Sep 17;124(9):745-51. Epub 2015 Apr 17.

Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China Ear Institute, Shanghai Jiaotong University, Shanghai, China Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China

Objectives: NOG is an antagonist to bone morphogenetic proteins and plays an important role in proper bone and joint development. Dominant mutations in NOG may lead to a series of symphalangism spectrum disorders. In this study, we aimed to identify the genetic cause and the pathogenic mechanism of an autosomal dominant disorder with cosegregating proximal symphalangism and conductive hearing impairment in a Chinese family.

Methods: Mutation screening of NOG was performed in the affected family members by polymerase chain reaction (PCR) amplification and direct sequencing. Western blotting analysis of NOG was performed in the leukocyte samples of the family members.

Results: A novel p.W150C heterozygous mutation in NOG was identified cosegregating with the proximal symphalangism disorder in the family. Western blotting analysis showed that the p.W150C mutation interferes with the dimerization of the mutant NOG.

Conclusions: Our results agreed with previously published results of in vitro studies and suggested that impaired dimerization of mutant NOG is an important pathogenic mechanism for the NOG-related symphalangism spectrum disorder.
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http://dx.doi.org/10.1177/0003489415582257DOI Listing
September 2015

Facial and lower cranial nerve function preservation in lateral approach for craniocervical schwannomas.

Eur Arch Otorhinolaryngol 2015 Sep 14;272(9):2207-12. Epub 2014 Jun 14.

Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiaotong University, 1665 Kongjiang Road, Shanghai, 200092, China,

The purpose of this study was to discuss surgical approach selection, surgical procedures, and treatment strategy for preservation of the facial and lower cranial nerve function in craniocervical schwannomas surgery. Between 2002 and 2011, 44 craniocervical schwannomas were operated in Xinhua hospital of Shanghai, China by the same surgical team. The records were reviewed retrospectively regarding clinical presentation, radiographic assessment, surgical approaches selection, surgical procedures and facial and lower cranial nerve follow-up outcomes. Headache or neck pain was present in 30 patients (68.2 %) and cervical mass in 9 patients (20.5 %). Cranial nerve impairments, mainly involving the vagus nerve, were present in 19 patients (43.2 %) and hypoglossal nerve in five patients (11.4 %). 22 tumors were intra- and extracranial, 10 were intra-cranial and 12 were extra-cranial. According to the tumor region, infratemporal fossa type A approach, petrous occipital transsigmoid approach and transcervial approach were selected for tumor removal. Gross-total resection was achieved in 40 patients (90.9 %). Adjunctive radiosurgery was used in the management of residual tumor in two patients; tumor control was ultimately obtained in all cases. During follow-up period, good facial function was obtained in 42 patients (95.5 %) and complete compensation of lower cranial nerve function was achieved in all patients. The preoperative estimation of tumor in nature is of great importance in the determination of proper surgical planning of craniaocervical schwannomas. Facial nerve and lower cranial nerve function can be preserved in maximal degree by proper surgical approaches and careful operative manipulation. Initial surgical resection followed by radiosurgery may be an effective option for some special patients.
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http://dx.doi.org/10.1007/s00405-014-3127-yDOI Listing
September 2015

The role of NF2 gene mutations and pathogenesis-related proteins in sporadic vestibular schwannomas in young individuals.

Mol Cell Biochem 2014 Jul 12;392(1-2):145-52. Epub 2014 Mar 12.

Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, 1665 Kongjiang Road, Shanghai, 200092, China.

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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http://dx.doi.org/10.1007/s11010-014-2011-9DOI Listing
July 2014
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