Chromatin Assembly Factor-1 (caf-1) and Poly-adp-ribose-polymerase (parp) Expression: Have They A Role In the Evaluation of Cell Proliferation and In Prognostic Evaluation of Oscc?

Oral cancer is an important contributor to the overall international cancer burden, with systematic tendencies towards increasing rates of incidence and mortality, particurarly in younger males. Over 200,000 new cases are reported annually worldwide, with an overall mortality rate of approximately 50%, even with modern medical services. There is still a need for new reliable biological markers able to predict the prognosis of single cases of oral squamous cell carcinoma (OSCC). The study of cell proliferation status has a role in prognostic evaluation of solid tumors. Recent papers have put forward CAF-1 as a useful novel proliferation marker and prognostic indicator in breast lesions. CAF-1 is a heterotrimeric protein complex, that delivers histones H3 and H4 to DNA during DNA replication or DNA repair, the largest subunit (p150) interacting directly with PCNA. PARP has been proposed as playing a key role in DNA repair, especially single strand binding repair. We studied, by immunohistochemistry and Western blot analysis (WB), the expression of CAF-1 and PCNA, in a selected series of 52 cases (mean age: 66.1 years) of primary OSCC of the head and neck region. A follow-up of at least 60 months was available. The results were correlated with those concerning the expression of PARP-1, a protein involved in DNA repair and/or induction of apoptosis. Our results indicate that CAF-1 may have a role as a new proliferation marker in OSCC. Moreover, variation of its expression could be related to altered expression of PARP- 1 in a subset of tumors, also suggesting a potential role as a prognostic marker in OSCC.