Overexpression of chromatin assembly factor-1 p60, poly(ADP-ribose) polymerase 1 and nestin predicts metastasizing behaviour of oral cancer

AIMS The natural history of oral squamous cell carcinomas (OSCCs) is variable and difficult to predict. This study aimed to assess the value of the expression of poly(ADP-ribose) polymerase 1 (PARP-1), chromatin assembly factor-1 (CAF-1)/p60 and the stem cell markers CD133, CD166, CD44, CD44v6 and nestin as markers of outcome and progression-free survival in OSCC patients. METHODS Clinical data were collected from 66 patients (41 male and 25 female, aged 29-92 years) who underwent surgery for OSCC of the tongue, floor, lips, and palate. During follow-up (range: 12-131 months), 14 patients experienced relapse/metastasis and/or death. The study was performed by immunohistochemistry on paraffin-embedded tumour tissues, western blot analysis of tumour protein lysates and human cell lines, and RNA silencing assays. In addition, the human papillomavirus (HPV) status of primary tumours was evaluated by immunohistochemistry and viral subtyping. Univariate and multivariate analyses were performed to determine the correlation between these parameters and the clinical and pathological variables of the study population. RESULTS AND CONCLUSIONS We found that a PARP-1(high) /CAF-1 p60(high) /nestin(high) phenotype characterized the OSCCs with the worst prognosis (all HPV-negative). This may be of benefit in clinical management, since radio-enhancing anti-PARP-1 and/or anti-CAF-1/p60 agents may allow radioresistance to be bypassed in the nestin-overexpressing, metastasizing OSCC cells.