title: Clock genes: their role in colorectal cancer.
abstract: Clock genes create a complicated molecular time-keeping system consisting of multiple positive and negative feedback loops at transcriptional and translational levels. This circadian system coordinates and regulates multiple cellular procedures implicated in cancer development such as metabolism, cell cycle and DNA damage response. Recent data support that molecules such as CLOCK1, BMAL1 and PER and CRY proteins have various effects on c-Myc/p21 and Wnt/β-catenin pathways and influence multiple steps of DNA damage response playing a critical role in the preservation of genomic integrity in normal and cancer cells. Notably, all these events have already been related to the development and progression of colorectal cancer (CRC). Recent data highlight critical correlations between clock genes' expression and pathogenesis, progression, aggressiveness and prognosis of CRC. Increased expression of positive regulators of this circadian system such as BMAL1 has been related to decrease overall survival while decreased expression of negative regulators such as PER2 and PER3 is connected with poorer differentiation, increased aggressiveness and worse prognosis. The implications of these molecules in DNA repair systems explain their involvement in the development of CRC but at the same time provide us with novel targets for modern therapeutic approaches for patients with advanced CRC.
authors.affiliation: Theodoros Karantanos, George Theodoropoulos, First Department of Propaedeutic Surgery, School of Medicine, University of Athens, 11725 Athens, Greece.
authors.forename: Theodoros
authors.initials: T
authors.lastname: Karantanos
authors.affiliation: Theodoros Karantanos, George Theodoropoulos, First Department of Propaedeutic Surgery, School of Medicine, University of Athens, 11725 Athens, Greece.
authors.forename: George
authors.initials: G
authors.lastname: Theodoropoulos
authors.affiliation: Theodoros Karantanos, George Theodoropoulos, First Department of Propaedeutic Surgery, School of Medicine, University of Athens, 11725 Athens, Greece.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Pektasides
authors.affiliation: Theodoros Karantanos, George Theodoropoulos, First Department of Propaedeutic Surgery, School of Medicine, University of Athens, 11725 Athens, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Gazouli
mesh_terms: D000818:Animals; D056926:CLOCK Proteins / Q000378:metabolism*; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000378:metabolism; D002454:Cell Differentiation; D002940:Circadian Rhythm; D015179:Colorectal Neoplasms / Q000378:metabolism*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D004249:DNA Damage; D018450:Disease Progression; D015870:Gene Expression; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D056950:Period Circadian Proteins / Q000378:metabolism; D011379:Prognosis; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D051176:beta Catenin / Q000378:metabolism
chemical_list: C493956:CDKN1A protein, human; D018797:Cell Cycle Proteins; D050759:Cyclin-Dependent Kinase Inhibitor p21; D009687:Nuclear Proteins; C421902:PER2 protein, human; D056950:Period Circadian Proteins; D016271:Proto-Oncogene Proteins c-myc; D014157:Transcription Factors; D051176:beta Catenin; D056926:CLOCK Proteins; D011505:Protein-Tyrosine Kinases; C499349:WEE1 protein, human
keywords: Clock genes; Colorectal cancer; Development; Prognosis