<b>Circadian Expression of Differentiated Embryonic Chondrocytes Expressed Genes 1 </b><b>and 2 in Human Oral Squamous Cell Carcinoma HSC-3 Cells </b>

Abstract

Autonomous rhythmicity of clock genes controls the circadian rhythm and endogenous circadian rhythms regulates various biochemical, physiological, and biological processes, with a periodicity of about 24 h. Entrainment circadian clock of cells detects distinct patterns of circadian oscillation for clock genes. Although circadian disruptions have been implicated in cancer development, the altered circadian rhythm in human oral cancer remains largely unknown. Here we show that, upon entrainment by serum shock, cultured human oral epithelial cancer cell line, HSC-3, maintain an inner circadian oscillator, with key clock genes DEC1 and DEC2 oscillating in a circadian fashion. Serum-shocked HSC-3 cells exhibited an about 24 h oscillatory pattern of DEC1 and DEC2 protein and mRNA expression. Taken together, the results indicated that the transcription factors DEC1 and DEC2 modulate a rhythmic transcriptional regulation mechanism which can drive the expression of downstream genes involved in many cellular processes.