Expression of cancer stem cell markers CD44, ALDH1 and p75NTR in actinic cheilitis and lip cancer.

PURPOSE: The aim of this work was to evaluate the expression of the cancer stem cell (CSC) markers CD44, ALDH1 and p75NTR in the ultraviolet-induced lesions actinic cheilitis (AC) and lip squamous cell carcinoma (LSCC), and to correlate it with p53 expression.

METHODS: Immunohistochemistry was performed in 4 cases of normal lip (NL), 43 of AC and 20 of LSCC.

RESULTS: All cases were positive for CD44, showing a membranous staining without differences between the groups. ALDH1 showed cytoplasmic staining and it was invariable amongst the grades of epithelial dysplasia and between AC and LSCC. p75NTR presented membranous/cytoplasmic staining in the basal and parabasal layer of NL and AC, while LSCC presented cytoplasmic staining in the peripheral layers of the tumor islands. p75NTR showed different expression amongst the dysplasia grades (p < 0.001) but no differences between AC and LSCC. p53 expression was similar amongst the dysplasia grades and between AC and LSCC. CD44, ALDH1 and p75NTR were unrelated amongst themselves and to p53 expression.

CONCLUSIONS: CSC markers are expressed in potentially malignant and malignant lesions of the lip. Their expressions were invariable between AC and LSCC and unrelated to p53. p75NTR expression increased with the worsening of epithelial dysplasia grade.