Chromatin assembly factor-1 (CAF-1)-mediated regulation of cell proliferation and DNA repair: a link with the biological behaviour of squamous cell carcinoma of the tongue?

AIMS: Squamous cell carcinoma (SCC) of the tongue shows aggressive behaviour and a poor prognosis. Clinicopathological parameters fail to provide reliable prognostic information, so the search continues for new molecular markers for this tumour. Chromatin assembly factor-1 (CAF-1) plays a major role in chromatin assembly during cell replication and DNA repair and has been proposed as a new proliferation marker. The aim of this study was to investigate its expression in SCC of the tongue. METHODS AND RESULTS: The immunohistochemical expression of the p60 and p150 subunits of CAF-1 were evaluated in a series of SCCs of the tongue. The findings were correlated with the expression of proliferation cell nuclear antigen (PCNA) and patients' clinicopathological and follow-up data. CAF-1/p60 was expressed in all the tumours, whereas CAF-1/p150 was down-regulated in a number of cases. Overexpression of CAF-1/p60 and down-regulation of CAF-1/p150 identified SCCs with poor outcome, in addition to the classical prognostic parameters. CONCLUSIONS: Simultaneous CAF-1-mediated deregulation of cell proliferation and DNA repair takes place in aggressive SCC of the tongue. Therefore, the evaluation of CAF-1 expression may be a valuable tool for evaluation of the biological behaviour of these tumours. This may be relevant to the introduction of improved follow-up protocols and/or alternative therapeutic regimens.