Decreased expression of DARPP-32 in oral premalignant and malignant lesions.
BACKGROUND
DARPP-32 is a neuronal protein that plays a central role in dopaminergic neurotransmission. Although DARPP-32 may contribute to the pathogenesis of several human malignancies, its expression has never been investigated in oral premalignant and malignant lesions.


METHODS
DARPP-32 expression was examined using immunohistochemistry in 14 normal oral mucosa, 5 normal lower lip mucosa, 41 oral leukoplakia (OL), 30 oral squamous cell carcinoma (OSCC) and 20 lower lip squamous cell carcinoma (LLSCC) specimens. Differences of its expression between groups were analyzed.


RESULTS
OSCC and OL with moderate or severe dysplasia showed lower DARPP-32 expression in relation to normal oral mucosa. LLSCC showed lower DARPP-32 expression than normal lower lip mucosa and OSSC.


CONCLUSIONS
The decreased expression of DARPP-32 in oral premalignant and malignant lesions suggests a tumor suppressor role for this protein in the tumorigenesis of these lesions.
Pimenta
Flávio Juliano
FJ
Departments of Oral Surgery and Pathology, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
Horta
Martinho Campolina Rebello
MC
Vidigal
Paula Vieira
PV
De Souza
Bruno Rezende
BR
De Marco
Luiz
L
Romano-Silva
Marco Aurélio
MA
Gomez
Ricardo Santiago
RS
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000378:metabolism*; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32 / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007972:Leukoplakia, Oral / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000378:metabolism; D009062:Mouth Neoplasms / Q000378:metabolism*
D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; C497928:PPP1R1B protein, human