Clock genes and gastric cancer

ABSTRACT The mental, physical and behavioural changes that follow a 24-hour cycle are defined as circadian rhythms, and this response to light and dark affects most living things, including animals, plants and microbes. Biological clocks are composed of specific molecules (clock genes) that interact with cells throughout the body and are the timing devices that organisms use to regulate circadian rhythms. Circadian rhythms have been observed in the human gastrointestinal tract. To this end, basal gastric acid production, epithelial cell proliferation, gastrointestinal motility and appetite regulation vary with the time of day. The abnormal expression of clock genes can alter normal circadian rhythms and subsequently cause a variety of illnesses, including cancers. The aim of this study was to discuss and summarize the relationship between the expression of clock genes and the development and progression of gastric cancer and to explore the possibility of using these genes as biomarkers in gastric cancer prognosis in patients. Abbreviations: RORE: retinoic acid-related orphan receptor response element; CLOCK: circadian locomotor output cycles kaput; BMAL1: brain and muscle ARNT-like protein 1; ARNTL: aryl hydrocarbon receptor nuclear translocator-like; PER: period; CRY: cryptochrome; mTOR: mammalian target of rapamycin; VNTR: variable number tandem repeat; cAMP/PKA: cyclic adenosine monophosphate/protein kinase A pathway