Cyclin D(1) and D(3) expression in vestibular schwannomas.
OBJECTIVE
The G1 regulators of the cell cycle, cyclin D(1) and D(3), have been implicated in the regulation of Schwann cell proliferation and differentiation. The purpose of this study is to evaluate cyclin D(1) and D(3) protein expression and the corresponding clinical characteristics of vestibular schwannomas.


METHODS
Tissue sections of 15 sporadic vestibular schwannomas were prepared. Immunohistochemical analysis of the vestibular schwannomas was performed with anticyclin D(1) and anticyclin D(3) antibodies. The immunoreactivity was evaluated in comparison with adjacent vestibular nerves. Tissue sections of breast carcinoma and prostate carcinoma were used as positive controls for cyclin D(1) and D(3) staining, respectively. Patient demographics, tumor characteristics, and cyclin D expression were reviewed, and statistical analysis was performed.


RESULTS
While the breast carcinoma control expressed abundant cyclin D(1) protein, none of the 15 vestibular schwannomas showed detectable cyclin D(1) staining. In contrast, seven of 15 vestibular schwannomas stained positive for the cyclin D(3) protein. Cyclin D(3) staining was taken up in the nucleus of schwannoma tumor cells in greater proportion than Schwann cells of adjacent vestibular nerve. Although sample size was small, no significant difference in the average age of presentation, tumor size, and male to female ratios for the cyclin D(3)(+) or cyclin D(3)(-) groups was found.


CONCLUSIONS
The Cyclin D(1) protein does not appear to play a prominent role in promoting cell cycle progression in vestibular schwannomas. In contrast, cyclin D(3) expression was seen in nearly half of the tumors examined, suggesting that it may have a growth-promoting role in some schwannomas. Further studies are needed to define its cellular mechanism.
Department of Otolaryngology Head and Neck Surgery, The Ohio State University, Columbus, Ohio 43205, USA.
Brian A
BA
Neff
Elly
E
Oberstien
Mark
M
Lorenz
Abhik R
AR
Chaudhury
D Bradley
DB
Welling
Long-Sheng
LS
Chang
D000912:Antibodies, Neoplasm / Q000276:immunology; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D002277:Carcinoma / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D019938:Cyclin D1 / Q000096:biosynthesis* / Q000276:immunology; D056743:Cyclin D3; D016213:Cyclins / Q000096:biosynthesis* / Q000276:immunology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009464:Neuroma, Acoustic / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D011471:Prostatic Neoplasms / Q000276:immunology / Q000378:metabolism / Q000473:pathology
D000912:Antibodies, Neoplasm; D014408:Biomarkers, Tumor; C534696:CCND3 protein, human; D056743:Cyclin D3; D016213:Cyclins; D019938:Cyclin D1