Evaluation of the p-AKT, p-JNK and FoxO3a function in oral epithelial dysplasia

Loss of heterozygosity and immunoexpression of PTEN in oral epithelial dysplasia and squamous cell carcinoma

INTRODUCTION

Oral epithelial dysplasia (OED) is a risk factor for developing subsequent oral squamous cell carcinoma (OSCC). Loss of heterozygosity (LOH) profiles have been validated as risk predictors of malignant transformation of OED. It is still unclear if Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) allelic loss also occurs in initial stage malignant lesions and if the allelic loss is involved as one of the mechanisms of oral carcinogenesis. Thus, this study objective investigate LOH of PTEN gene and the immunohistochemical expression of the protein in OED and OSCC samples.

MATERIAL AND METHODS

Formalin-fixed paraffin-embedded samples of 19 OEDs and 16 OSCCs were included to immunohistochemistry and LOH analysis. Two polymorphic microsatellite markers (AFMA086WG9 and D10S1765) located in chromosome 10 were used in this study for LOH analysis. For immunohistochemical analysis, 5 random fields with 400× magnification were evaluated quantitatively and qualitatively in epithelial and neoplastic cells.

RESULTS

AFMA086WG9 marker only demonstrated LOH in OEDs cases (10.5%). D10S1765 marker demonstrated LOH in 57.2% of OEDs and 50% of OSCCs. Higher nuclear immunostaining was detected in cases of OSCCs when compared to OEDs (p < .001) and there was strong cytoplasmic immunoexpression in OSCCs (p < .045).

CONCLUSIONS

We provide evidence that the allelic loss of PTEN is present in premalignant oral lesions and OSCCs, however the LOH of PTEN does not seems to influence its protein expression.

Immunohistochemical Evaluation of GLUT-3 and GLUT-4 in Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma

Objectives

To evaluate immunohistochemically the expression of GLUT-3 and GLUT-4 in oral epithelial dysplasia (OED) and the oral squamous cell carcinoma (OSCC) and assess possible involvement in the malignant transformation of oral lesions.

Methods

Tissue samples of 15 cases of OSCC and 15 of OED were subjected to immunohistochemistry with anti-GLUT-3 and anti-GLUT-4 antibodies. Five fields of each case were analyzed, to provide percentages of positive cells at 400X magnification.

Result

GLUT-3 and GLUT-4 were positive in 100% of the analyzed samples, the percentage immunolabeling for GLUT-3 ranging from 19% to 73% in the OED group and 10% to 89% in the OSCC group. Positive immunolabeling for GLUT-4 ranged from 15.2% to 79.9% in the OSCC group and 27.1% to 92.6% in the OED group. Statistical analysis with the Mann-Whitney test revealed that there was a higher expression of GLUT-4 in the OED group than in the OSCC group (p=0.04) without any significant difference in the GLUT-3 expression (p=0.852).

Conclusion

GLUT-4 expression may indicate some role in oncogenic mechanisms which can determine a malignant phenotype. Thus, it is suggested that further studies on the role of GLUT-3 in oral carcinogenesis be conducted.