DIFFERENTIATION AND CATHEPSIN-D EXPRESSION IN HUMAN ORAL TUMORS

Objectives/Hypothesis: This study aimed to ascertain whether cathepsin D expression could be related to the stage of differentiation of oral tumors. Study Design: Human oral biopsies of 10 squamous cell carcino mas and of the corresponding perilesional normal tissues were used. Th e tumors had all been clinically graded as advanced stage but nonmetas tatic; five were classified histopathologically as poorly differentiat ed. Methods: The gene expression of cathepsin D and keratin K13 in the biopsies was measured by reverse transcription polymerase chain react ion. Ratios of tumor-to-control readings helped compensate for sample variability. Results: Keratin K13, as a suprabasal cell marker, tended to confirm the histological grading of the tumors (but was not otherw ise useful in distinguishing tumors from normal tissue). Substantial o verexpression of cathepsin D was found in the poorly differentiated tu mors. Conclusions: Cathepsin D overexpression is considered a prognost ic indicator of metastasis. In this sample, it was also associated wit h dedifferentiation. Cathepsin D might serve as a valuable gauge in cl inical exploration of the connection between dedifferentiation and met astasis.