Co-Expression of Putative Cancer Stem Cell Markers, CD133 and Nestin, in Skin Tumors

Background: Cancer stem cells (CSC) are populations of cells responsible for tumor initiation, progression andtherapeutic resistance in many cancers. In the present study, we aimed to investigate the expression pattern andclinical significance of two CSC markers, CD133 and Nestin, in a series of skin tumors. Materials and
Methods:One hundred and thirteen paraffin blocks from skin cancers including 16 (14%) cases of melanoma, 37 (33%)of squamous cell cancer (SCC) and 60 (53%) of basal cell cancer (BCC) were collected and assembled in a tissuemicroarray (TMA). The samples were immunohistochemically examined for the expression of CD133 and Nestin.Expression of these markers was also correlated with clinicopathological parameters.
Results: A significantdifference was observed in the expression of CD133 and Nestin in melanomas, SCC and BCC (p value=0.001).Furthermore, the level of expression was significantly higher in the melanomas compared to the SCC and BCCtumors. Expression of CD133 in the melanoma was significantly associated with increased tumor invasiveness (pvalue=0.05), a higher rate of metastasis (p value=0.04) and the presence of ulceration (p value=0.02). Increasedexpression of Nestin was observed in metastatic melanoma (p value=0.04), while no statistically significantcorrelation was found with other clinicopathological parameters including Breslow thickness, Clark level andulceration.
Conclusions: Elevated expression levels of CD133 and Nestin in the melanomas are associated withadvanced disease, with more aggressive and metastatic skin tumors. Therefore, these markers could be potentialtherapeutic targets for malignant tumors of the skin.