Expression levels of ALDH1A2 and ALDH1A3 are altered in human tissue biopsies in invasive squamous cell carcinoma

The regulation of gene expression by retinoids has been shown to be profoundly altered in various types of precancerous and cancerous lesions, including cutaneous squamous cell carcinoma (cSCC). Aldehyde dehydrogenase family 1, subfamily members A2 (ALDH1A2) and A3 (ALDH1A3) participate in the oxidation of retinal to retinoic acid and their expression has been implicated in various types of cancers. The purpose of this study is to compare the intensity and localization of ALDH1A2 and ALDH1A3 in various stages of cSCC. Forty-two diseased biopsies and 32 healthy controls were used in this study. Immunohistochemistry was used to detect the immunoreactivity and localization of ALDH1A2 and ALDH1A3. Results showed percent ALDH1A2 positive cells were significantly higher in the tumor and stroma of actinic keratosis and invasive SCC groups than other groups. ALDH1A3 expression levels were significantly higher in tumors of all stages of cSCC compared to the epidermis of the control group.