Mutation/SNP | Possible mechanism | Phenotype |
---|---|---|
CLOCK | Â | Self-renewal capacity of mammary progenitor cells becomes compromised (our unpublished data) |
Hypermethylation of Clock promoter | Mediates CCL5 expression | Reduced breast cancer risk [36] |
NPAS2 Ala394Thr SNP | Altered NPAS2 protein structure | Increased breast cancer risk [55] |
Per1 deficient | Alters expression of checkpoint proteins ATM and Chk2 | Increased proliferation [41] |
Per1 overexpression | Impairs p53 leading to decreased apoptosis, deregulation of c-myc/CyclinD1/Gadd45 | Reduces proliferation in colon, lung and breast cancer cell lines [41] |
Per2 deficient | Increases OCT1 binding to EMT genes Slug, Snail and Twist1 | Higher tumour incidence, increased susceptibility to radiation-induced malignant lymphoma [39] |
Per2 overexpression | Cell cycle arrest, growth inhibition, apoptosis induction | |
Per3 deficient | Â | |
Cry deficient | Disrupted cell cycle regulation via de-regulation of Wee-1 and CyclinD1 | Â |
BMAL1/Era/Per2 KO | Prevents mammary acinar formation | Facilitates invasion and metastasis [56] |
BMAL1 overexpression | Binds to p53 promoter | Tumour suppression [61] |