Schwannomas, benign tumors with a senescent phenotype.
Schwannomas are benign nerve sheath tumors that only very rarely undergo malignant changes. Oncogenic-induced senescence is a defense mechanism against such malignant transformation. Different molecular pathways are involved in this process, such as RAS-RAF-MAPK. Based on the fact that the RAS-RAF-MAPK pathway is known to be activated in peripheral nerve sheath tumors, this study analyzes senescence markers in Schwannomas to demonstrate the possible role of senescence in their genesis.



A retrospective immunohistochemical study was done in 39 schwannoma and 18 malignant peripheral nerve sheath tumors (MPNST). Staining for p16INK4a, Ki67, p53 and CyclinD1 was performed in all the cases. Additionally, β-galactosidase staining was done in those cases in which frozen tissue was available (n=8).



Higher levels of p16INK4a (p=0.0001) and lower levels of Ki67 (p=0.0001) were found in Schwannomas. Beta-galactosidase activity was positive in 5/5 Schwannomas and negative in 3/3 MPNST.



Our results support the senescence nature of Schwannomas and the absence of a senescence phenotype in MPNST.
Pathology Department, Hospital Universitari Vall d'Hebron, and Universitat Autonoma de Barcelona, Barcelona, Spain.
S
S
Simonetti
J.
C
C
Serrano
Pathology Department, Hospital Universitari Vall d'Hebron, and Universitat Autonoma de Barcelona, Barcelona, Spain.
J
J
Hernández-Losa
Pathology Department, Hospital de San Pau, and Universitat Autonoma de Barcelona, Barcelona, Spain.
S
S
Bagué
Pathology Department, Hospital Parc Taulí, Sabadell, and Universitat Autonoma de Barcelona, Barcelona, Spain.
R
R
Orellana
Oncology Department, Hospital Universitari Vall d'Hebron, Barcelona. Spain.
C
C
Valverde
Pathology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain.
M E
ME
Lleonart
Pathology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain.
M
M
Aizpurua
Oncology Department, Hospital Universitari Vall d'Hebron, Barcelona. Spain.
J
J
Carles
Pathology Department, Hospital Universitari Vall d'Hebron, and Universitat Autonoma de Barcelona, Barcelona, Spain. sramon@vhebron.net.
S
S
Ramón y Cajal
Pathology Department, Hospital Universitari Vall d'Hebron, and Universitat Autonoma de Barcelona, Barcelona, Spain. cromagos@vhebron.net.
C
C
Romagosa
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002471:Cell Transformation, Neoplastic / Q000378:metabolism / Q000473:pathology; D005260:Female; D006258:Head and Neck Neoplasms / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009442:Neurilemmoma / Q000378:metabolism / Q000473:pathology*; D010641:Phenotype; D012189:Retrospective Studies; D012983:Soft Tissue Neoplasms / Q000378:metabolism / Q000473:pathology*; D055815:Young Adult
D014408:Biomarkers, Tumor