title: Stromal myofibroblasts in potentially malignant and malignant lesions of the oral cavity.
abstract: Previous studies have demonstrated that myofibroblasts in the adjacent stroma are involved in the development and progression of malignant tumors. The aim of this study was to investigate the involvement of myofibroblasts in the progression of oral squamous cell carcinomas (OSCCs) by determining myofibroblast density in potentially malignant and malignant oral lesions. A total of 69 potentially malignant oral lesions (leukoplakias with mild, moderate or severe dysplasia), 90 OSCCs (well-, moderately and poorly differentiated), eight oral verrucous carcinomas and 29 fibrous hyperplasias were examined for the presence of myofibroblasts using immunohistochemical detection of isoform α of smooth muscle actin. Myofibroblasts were not identified in the adjacent stroma of fibrous hyperplasias and potentially malignant oral lesions, whereas 59.8% of the oral carcinomas exhibited myofibroblasts in various densities. The density was significantly higher in moderately and poorly differentiated OSCCs when compared with well-differentiated tumors (P=0.04 and P=0.007, respectively). In verrucous carcinomas, the specific variant of well-differentiated OSCC, stromal myofibroblasts were not detected. The results of the present study demonstrated that immunodetection of myofibroblasts does not aid with the determination of the malignant transformation potential of oral dysplasias, although moderately and poorly differentiated tumors exhibited a significantly higher density of myofibroblasts. The results reinforce the hypothesis that myofibroblasts may contribute to oral tumorigenesis, indicating that verification and monitoring of such may serve as a putative marker of OSCC behavior.
authors.affiliation: Department of Oral Diagnosis, School of Dentistry, State University of Campinas, Piracicaba, São Paulo 13414-018, Brazil.
authors.forename: Priscila Campioni
authors.initials: PC
authors.lastname: Rodrigues
authors.affiliation: Department of Oral Diagnosis, School of Dentistry, State University of Campinas, Piracicaba, São Paulo 13414-018, Brazil ; Department of Dentistry, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte 59072-970, Brazil.
authors.forename: Márcia Cristina
authors.initials: MC
authors.lastname: DA Costa Miguel
authors.affiliation: Department of Oral Diagnosis, School of Dentistry, State University of Campinas, Piracicaba, São Paulo 13414-018, Brazil.
authors.forename: Sibele Nascimento
authors.initials: SN
authors.lastname: DE Aquino
authors.affiliation: Department of Oral Diagnosis, School of Dentistry, State University of Campinas, Piracicaba, São Paulo 13414-018, Brazil.
authors.forename: Felipe Paiva
authors.initials: FP
authors.lastname: Fonseca
authors.affiliation: Department of Oral Diagnosis, School of Dentistry, State University of Campinas, Piracicaba, São Paulo 13414-018, Brazil.
authors.forename: Alan Roger Dos Santos
authors.initials: AR
authors.lastname: Silva
authors.affiliation: Brazilian Biosciences National Laboratory, National Center for Research in Energy and Materials, Campinas, São Paulo 13083-970, Brazil.
authors.forename: Adriana Franco Paes
authors.initials: AF
authors.lastname: Leme
authors.affiliation: Department of Oral Diagnosis, School of Dentistry, State University of Campinas, Piracicaba, São Paulo 13414-018, Brazil.
authors.forename: Ricardo D
authors.initials: RD
authors.lastname: Coletta
keywords: myofibroblast; oral squamous cell carcinoma; oral verrucous carcinoma; potentially malignant oral lesions