RARβ Expression in Keratinocytes from Potentially Malignant Oral Lesions: The Functional Consequences of Re-Expression by De-Methylating Agents

Loss of RARβ2 expression by promoter methylation is an early event in oral carcinogenesis. Understanding the mechanisms and consequences RARβ loss may aid understanding disappointing results retinoid chemoprevention trials. This study aimed to describe effects all-trans retinoic acid (ATRA) de-methylating agent 5-Aza-2′ deoxycytidine (5-AZA-CdR) on a panel immortal potentially malignant lesion (PMOL) cell cultures. was assessed PMOL tissues immunohistochemistry. Cells were treated with ATRA ± 5-AZA-CdR, cycle senescence assessed. In tissues, variable, but lower biopsies which gave rise Treatment iPMOL cells resulted little change expression, addition 5-AZA-CdR significant increases. The variable be related as this has wider cycle. Overall, response treatment dependent several factors, including RARβ-promoter methylation. These findings help explain lack consistent effect retinoids PMOLs seen