Immunoexpression of hMSH2 and hMLH1 in oral squamous cell carcinoma and its relationship to histological grades of malignancy.
BACKGROUND
The aim of this study was to describe the human mutS homolog 2 (hMSH2) and human mutL homolog 1 (hMLH1) immunoexpression in different areas of oral squamous cell carcinoma (OSCC) - central/superficial (C/S) and invasive tumor front (ITF) - in an attempt to verify if the histological grade of malignancy interferes in this expression.


METHODS
Forty-six samples of OSCC were analyzed histologically. Twenty-six cases (56.5%) presented ITF. Histological grades of malignancy were evaluated in all samples, and immunohistochemistry was applied using specific antibodies against hMSH2 and hMLH1 proteins. Immunoexpression was semiquantitatively scored, and results were correlated with their histological grades of malignancy.


RESULTS
The hMSH2 immunoexpression in both C/S and ITF was not correlated with histological grades of malignancy, whereas hMLH1 overexpression was correlated (P = 0.043) and associated (P = 0.041) with well-differentiated tumors. In addition, hMHL1 reduction or negative expression was detected in poorly differentiated tumors. Moreover, negative expression for hMSH2 and hMLH1 proteins was demonstrated in some cases of OSCC.


CONCLUSIONS
The findings of the present study indicate that the histological grade of malignancy interferes in hMLH1 immunoexpression. The negativity for both hMSH2 and hMLH1 proteins in some cases suggests a possible association between OSCC and hereditary non-polyposis colorectal cancer. Further investigation from future studies is needed to elucidate this supposition.
Fernandes
Anacelia Mendes
AM
Department of Oral Surgery and Pathology, School of Dentistry, Universidade Federal de Minas Gerais, Minas Gerais, Brazil.
Ramos-Jorge
Maria Letícia
ML
Cardoso
Sergio Vitorino
SV
Loyola
Adriano Mota
AM
Mesquita
Ricardo Alves
RA
Aguiar
Maria Cássia Ferreira
MC
D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000378:metabolism / Q000473:pathology*; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein / Q000378:metabolism*; D009361:Neoplasm Invasiveness; D009687:Nuclear Proteins / Q000378:metabolism*; D018709:Statistics, Nonparametric
D048868:Adaptor Proteins, Signal Transducing; D014408:Biomarkers, Tumor; C501486:MLH1 protein, human; D009687:Nuclear Proteins; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein