Thioredoxin and metallothionein: Homeostasis-related proteins in lip carcinogenesis.
OBJECTIVE
Thioredoxin (Trx) and metallothionein (MT) are involved in the development of some carcinomas; however, the role of these proteins in labial carcinogenesis has not yet been tested. The aims of the study were to evaluate and to correlate the immunoexpression of Trx and MT in actinic cheilitis, lip squamous cell carcinoma, and normal vermillion lip mucosa.


METHODS
Immunohistochemistry was undertaken for Trx and MT in samples of actinic cheilitis, lip squamous cell carcinoma, and normal lip mucosa. Qualitative and semi-quantitative evaluations were conducted. The proportion of stained cells, intensity of staining, and the cell compartment labeled were evaluated. A quickscore index was also calculated by multiplying the values of extension and intensity of nuclear and cytoplasmic staining, respectively, giving a maximum value of 9. Statistics were performed.


RESULTS
A remarkable nuclear Trx staining was seen in normal lip mucosa and cheilitis, not in carcinoma (p<0.05). Cytoplasmic Trx expression was widely detected in all lesions (p>0.05). MT was broadly expressed in nuclei and cytoplasm of carcinoma, but not in normal lip mucosa and cheilitis (p<0.05). Quickscores were in accordance with the qualitative results.


CONCLUSIONS
The current study showed a different immunopattern of Trx and MT between normal lip mucosa, actinic cheilitis and lip squamous cell carcinoma. The cellular compartment-based analyses evidenced differences that can be related to the proteins function. Considering the relevant roles of these proteins in cellular homeostasis, they seem to have an important role in lip carcinogenesis.
Universidade Federal de Minas Gerais, School of Dentistry, Department of Oral Surgery and Pathology, Av. Antônio Carlos 6627, Pampulha, CEP 31.270-901, Belo Horizonte, Minas Gerais, Brazil. Electronic address: pccaldeira@ufmg.br.
Patrícia C
PC
Caldeira
Universidade Federal de Minas Gerais, School of Dentistry, Department of Oral Surgery and Pathology, Av. Antônio Carlos 6627, Pampulha, CEP 31.270-901, Belo Horizonte, Minas Gerais, Brazil.
Laíssa S
LS
Silva
Universidade Federal de Goiás, School of Dentistry, Department of Oral Surgery and Pathology, Av. Universitária Esquina com 1ª Avenida s/n, Setor Universitário, CEP: 74605-220, Goiânia, Goiás, Brazil.
Aline C
AC
Batista
Universidade Federal de Minas Gerais, School of Dentistry, Department of Oral Surgery and Pathology, Av. Antônio Carlos 6627, Pampulha, CEP 31.270-901, Belo Horizonte, Minas Gerais, Brazil.
Maria Cássia F
MC
Aguiar
D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D002613:Cheilitis / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008048:Lip Neoplasms / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008668:Metallothionein / Q000378:metabolism*; D008875:Middle Aged; D060787:Neoplasm Grading; D013879:Thioredoxins / Q000378:metabolism*
D014408:Biomarkers, Tumor; D013879:Thioredoxins; D008668:Metallothionein
Actinic cheilitis; Lip neoplasms; Metallothionein; Squamous cell carcinoma; Thioredoxin