Restricted-expressed proliferation-associated protein (Repp86) expression in squamous cell carcinoma of the oral...

To determine the expression of repp86 (restricted-expressed protein of 86 kDa theoretical molecular mass), a proliferation- associated protein expressed in S-, G(2)- and M-phases of the cell cycle, in samples of normal mucosa as well as squamous cell carcinoma of the oral cavity (OSCC).

The repp86 labeling index (LI) was determined imunohistochemically in ten samples of normal oral mucosa and 59 samples of OSCC. Repp86 LI was correlated with tumor stage, histopathologic grading, and the expression of Ki-67 and topoisomerase IIalpha.

Repp86 was detectable in all tissues analyzed. The mean LI was 4.7% for normal mucosa and 18.4% for squamous cell carcinoma (p < 0.0001). Repp86 expression was not related to tumor size, lymph node invasion, or histopathologic grading but was positively correlated with Ki-67 index (r = 0.48; p < 0.01) as well as with topoisomerase IIalpha (r = 0.39; p < 0.01). Ki-67 and topoisomerase IIalpha levels were also significantly correlated with each other (r = 0.34; p < 0.05).

These results indicate that repp86 expression can be an additional proliferation marker among Ki-67 and topoisomerase IIalpha in OSCC. Further research will be directed at the evaluation of the prognostic value of repp86 expression in OSCC as well as in leukoplakia and early-stage OSCC.