Table 1 Association of clock genes and proteins with various forms of cancers.

Sporadic and familiar breast tumors

Decreased expression levels

Per1 Per2

49

Familiar breast tumors (than sporadic)

Lower expression levels

Per1

49

Survival of breast cancer cells

Methylation of promoters

Per1, Cry1

50

Proliferation of breast cancer cells

Methylation of promoters

Per

118

Higher risk of breast cancer

Polymorphisms

Clock

51

Inhibits breast cancer cell proliferation and tumor growth

Expression

Per1

89

Breast cancer cell proliferation and tumor growth

Downregulation

Per2

91

ER/PR-negative cases of breast cancer

SNPs

Clock

150

Breast cancer

Histone acetyltransferase activity

CLOCK (protein)

154

Tumor apoptosis in breast cancer

Increased expression

Per2

153

Prostate cancer risk and hormone-related breast cancer

SNPs

NPAS2

53,151

Non-Hodgkin lymphoma and acute lymphocytic leukemia

Epigenetic inactivation (via CpG hypermethylation)

Bmal1

52

Non-Hodgkin lymphoma

Genetic variations, functional polymorphism

Cry2, NPAS2

53,54

Chronic myeloid leukemia

Methylation

Per3

55

Prostate cancer

Downregulation

Per1

57

Prostate cancer

Increased expression level

Per2, Clock

120

Prostate cancer

Decreased expression levels

Bmal1

120

Glioma

Lower expression rates

Per1, Per2

60,61

Suppression of proliferation in pancreatic cancer

Expression

Per1, Per2

62,63

Proliferation of human pancreatic cancer cell line

Knockdown

Per1

119

Epithelial ovarian cancer

Low expression levels

Cry1, Bmal1

66

Endometrial cancer

CpG methylation

Per1, Per2, Cry1

67

Colorectal cancer

Increased expression level

Tim

68

Colon cancer

Downregulation

Per2

106,107

Undifferentiated colorectal tumors

Decreased expression levels

Per1

114

Chronic myeloid leukemia

Downregulation

Per1, Per2, Per3,

CRY1–2, TIM

70

Intestinal epithelial neoplastic transformation

PER2 protein degradation

Per2

72