Aggressive vestibular schwannomas showing postoperative rapid growth - their association with decreased p27 expression.
Vestibular schwannomas (VSs) are relatively slow growing tumors. However, some rapidly regrow or recur after surgical resection. The objective of this study was to identify those molecular characteristics predicting rapid recurrence after surgical resection. Immunohistochemically determined expressions of several cell cycle regulators and apoptosis-associated proteins in 12 cases of aggressive VS (AVS) and in 15 control cases of usual VS (UVS) cases were compared. The expressions of p53 and Bax (pro-apoptotic protein), Bcl-2 (anti-apoptotic protein), Fas, and Fas-L (apoptotic death receptor and ligand), caspase 3 (apoptotic effector caspase proteins), and p27 and p21 (cyclin-dependent kinase inhibitors) were analyzed using tissue array blocks. Loss of p27 expression was observed in 8 of 12 AVS cases (67%) and in 3 UVS cases (20%); p21 was expressed in all cases. Loss of Bax was observed in 3 AVS and 3 UVS cases. The anti-apoptotic protein, Bcl-2, was expressed in 9 AVS (75%) and 11 UVS (73%), and p53, Fas-L, and caspase 3 were negative and Fas was positive in all AVS and UVS cases. Of these, only the loss of p27 was statistically significant (P = 0.02). The loss of p27 in AVS may explain the unusually high proliferative potential of AVS versus UVS, and p27 may be a predictor of VS aggressiveness. The expressions of other apoptosis associated proteins were not significantly different in the two groups. This may be the first report to identify a molecular entity associated with aggressive VS. However, further studies are required.
Seol
Ho Jun
HJ
Department of Neurosurgery, Kangwon National University College of Medicine, Chuncheon, Korea.
Jung
Hee-Won
HW
Park
Sung-Hye
SH
Hwang
Sung-Kyun
SK
Kim
Dong Gyu
DG
Paek
Sun Ha
SH
Chung
Young-Seob
YS
Sub Lee
Chang
C
D049109:Cell Proliferation; D016009:Chi-Square Distribution; D003390:Cranial Nerve Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery*; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000032:analysis* / Q000235:genetics; D015536:Down-Regulation; D005500:Follow-Up Studies; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D007723:Korea; D008279:Magnetic Resonance Imaging; D009364:Neoplasm Recurrence, Local; D009464:Neuroma, Acoustic / Q000378:metabolism / Q000473:pathology* / Q000601:surgery*; D011184:Postoperative Period; D012086:Reoperation; D012189:Retrospective Studies; D013997:Time Factors; D000160:Vestibulocochlear Nerve Diseases / Q000378:metabolism / Q000473:pathology* / Q000601:surgery*
D050760:Cyclin-Dependent Kinase Inhibitor p27