OBJECTIVETo investigate the molecular biological mechanism of chronoexercise regulating circadian.

METHODSExpressions of mPer1 and mPer2 in the diencephalon of golden hamster were determined 2 hours after acute exhaustive exercise (circadian time 6) by quantitative RT-PCR.

RESULTSChronoexercise at CT6 significantly decreased expressions of mPer1 and mPer2 in the diencephalon of golden hamster.

CONCLUSIONInhibitory effect of chronoexercise on Per1 and Per2 mRNA levels in the diencephalon of golden hamster at CT6 may be achieved transcription-translation-based autoregulatory negative feedback loop.

Animals ; Circadian Rhythm ; physiology ; Cricetinae ; Gene Expression ; Period Circadian Proteins ; genetics ; metabolism ; Physical Conditioning, Animal ; RNA, Messenger ; genetics ; Reverse Transcriptase Polymerase Chain Reaction

Circadian clocks are the endogenous oscillators that harmonize a variety of physiological processes within the body. Although many urinary functions exhibit clear daily or circadian variation in diurnal humans and nocturnal rodents, the precise mechanisms of these variations are as yet unclear. In the present study, we demonstrate that Per2 promoter activity clearly oscillates in neonate and adult bladders cultured ex vivo from Per2::Luc knock-in mice. In subsequent experiments, we show that multiple local oscillators are operating in all the bladder tissues (detrusor, sphincter and urothelim) and the lumbar spinal cord (L4-5) but not in the pontine micturition center or the ventrolateral periaqueductal gray of the brain. Accordingly, the water intake and urine volume exhibited daily and circadian variations in young adult wild-type mice but not in Per1-/- Per2-/- mice, suggesting a functional clock-dependent nature of the micturition rhythm. Particularly in PDK mice, the water intake and urinary excretion displayed an arrhythmic pattern under constant darkness, and the amount of water consumed and excreted significantly increased compared with those of WT mice. These results suggest that local circadian clocks reside in three types of bladder tissue and the lumbar spinal cord and may have important roles in the circadian control of micturition function.
Animals ; *Circadian Clocks ; Drinking ; Mice ; Organ Specificity ; Periaqueductal Gray/metabolism/physiology ; Period Circadian Proteins/genetics/*metabolism ; Pons/metabolism/physiology ; Spinal Cord/*metabolism/physiology ; Urinary Bladder/innervation/metabolism/*physiology ; Urination

OBJECTIVEThis study investigates the circadian variation rules of the clock gene Per2 and clock-controlled genes of vascular endothelial growth factor (VEGF), Ki67, c-Myc, and P53 in different stages of carcinogenesis in buccal mucosa carcinoma and their roles in the development of buccal mucosa carcinoma.

METHODSNinety Syrian golden hamsters were housed under. 12 h light/12 h dark cycles. Dimethylbenzanthracene (DMBA) was used to establish the carcinoma model by smearing the golden hamster buccal mucosa. Before DMBA painting and after 6 and 14 weeks, the hamsters were sacrificed at six time points within a period of 24 h (i.e., 4, 8, 12, 16, 20, and 24 h after light onset), and the normal buccal mucosa, precancerous lesions, and cancer tissues were simultaneously obtained. Hematoxylin and eosin stained sections were prepared to observe the canceration of each tissue. Real time polymerase chain reaction was used to detect the mRNA expression of Per2, VEGF, Ki67, c-Myc, and P53. Cosine analysis was employed to determine the circadian-rhythm variations of Per2, VEGF, Ki67, c-Myc, and P53 mRNA expression in terms of median, amplitude, and acrophase.

RESULTSThe expression of Per2, VEGF, P53, and c-Myc mRNA in three different stages appeared with circadian rhythms (P<0.05), whereas the Ki67 mRNA was expressed with circadian rhythm only in normal and precancerous lesion stages (P<0.05). The midline-estimating statistic of rhythms (MESORs) of Per2 and P53 mRNA were significantly down-regulated with the development of cancer (P<0.05), whereas the MESORs of VEGF, c-Myc, and Ki67 mRNA were up-regulated (P<0.05). The amplitude of P53 mRNA significantly decreased with the development of cancer (P<0.05). Moreover, compared with the normal group, the amplitudes of Per2, VEGF, Ki67, and c-Myc mRNA significantly increased in precancerous lesions and cancer tissue (P<0.05). In precancerous stage, the acrophases of Per2, VEGF, and c-Myc mRNA were earlier than that in the normal group, whereas that of Ki67 and P53 mRNA were delayed.

CONCLUSIONThe circadian-rhythm characteristics of the clock gene Per2 and clock-controlled gene expression of VEGF, Ki67, c-Myc, and P53 mRNA have changed with the occurrence and development of carcinoma.

9,10-Dimethyl-1,2-benzanthracene ; Animals ; Carcinogenesis ; Carcinoma, Squamous Cell ; metabolism ; Circadian Rhythm ; Cricetinae ; Mesocricetus ; Mouth Mucosa ; metabolism ; Mouth Neoplasms ; metabolism ; Neoplasm Staging ; Period Circadian Proteins ; genetics ; metabolism ; RNA, Messenger ; Real-Time Polymerase Chain Reaction ; Vascular Endothelial Growth Factor A

OBJECTIVETo determine the regulatory effects of the circadian clock gene Per1 on cell cycle-related genes and its influence on the proliferation, apoptosis, cycle, and tumorigenicity in vivo of human oral squamous cell carcinoma SCC15 cells.

METHODSThree groups of the short hairpin RNA (shRNA) of lentivirus recombinant plasmids were designed against the RNA of Per1 and then transfected to the SCC15 cells. The optimum interference group was screened through Western blot and quantitative real-time PCR (qRT-PCR) and assigned as the experimental group. The transfected lentivirus plasmid without an interference effect on any gene was set as the control group (Control-shRNA). Untreated SCC15 cells were set as the blank group. The mRNA expressions of cell cycle-related genes, namely, Per1, p53, Cyclin D1, Cyclin E, Cyclin A2, Cyclin B1, CDK1, CDK2, CDK4, CDK6, p16, p21, Wee1, cdc25, E2F, and Rbl1 in each group were detected through qRT-PCR. The cell proliferation, apoptosis, and cell cycle distribution in each group were evaluated through flow cytometry. The cells of the experimental group and the blank group were subcutaneously inoculated in nude mice to observe tumorigenesis.

RESULTSThree groups of Per1-shRNA lentivirus plasmids were constructed successfully. Among the groups, the Per1-shRNA- I group exhibited the highest interference effect, as indicated by qRT-PCR and Western blot analysis. As such, this group was set as the experimental group. The mRNA expression levels of CyclinD1, CyclinE, CyclinB1, CDK1, and Wee1 gene in the Per1-shRNA-I group were significantly higher than those in the Control-shRNA group and the SCC15 group (P < 0.05). By contrast, the mRNA expression levels of p53, Cyclin A2, p16, p21, and cdc25 in the Per1-shRNA-I group were significantly lower than those in the Control-shRNA group and the SCC15 group (P < 0.05). The mRNA expression levels of each gene between the Control-sLRNA group and the SCC15 group did not significantly differ (P > 0.05). The mRNA expression levels of CDK2, CDK4, CDK6, E2F, and Rb1 did not significantly differed in the three groups (P > 0.05). The proliferation index of the Perl-shRNA-I group was significantly higher than those of the Control-shRNA group and the SCC15 group (P < 0.05). The apoptosis index of the Per1-shRNA-I group was significantly lower than those of the Control-shRNA group and the SCC15 group (P < 0.05). The number of S-phase cells in the Per1-shRNA-I group was significantly lower than those of S-phase cells in the Control-shRNA group and the SCC15 group (P < 0.05). The number of G2/M-phase cells in the Per1-shRNA-I group was significantly higher than those of G2/M-phase cells in the Control-shRNA group and the SCC15 group (P < 0.05). Conversely, the proliferation index, apoptotic index, and cell cycle distribution of the cells in the Control-shRNA group did not significantly differ from those of the SCC15 group (P > 0.05). The tumorigenic ability in vivo was significantly enhanced in the Per1-shRNA-I group (P < 0.05).

CONCLUSIONPer1 is an important tumor suppressor gene. Per1 can regulate a large number of downstream cell cycle-related genes. The alteration of its expression can affect cell cycle progression, proliferation, apoptosis imbalance, and tumorigenic ability in vivo. Further studies on Per1 may elucidate cancer development and provide novel effective molecular targets for cancer treatment.

Animals ; Apoptosis ; Carcinoma, Squamous Cell ; Cell Cycle ; Cell Line, Tumor ; Cell Proliferation ; Circadian Clocks ; genetics ; Cyclin D1 ; Humans ; Mice ; Mice, Nude ; Mouth Neoplasms ; Period Circadian Proteins ; genetics ; Plasmids ; RNA, Small Interfering ; Real-Time Polymerase Chain Reaction ; Transfection

OBJECTIVETo investigate the relationship between genetic variantions of circadian clock genes and risk of breast cancer.

METHODSA case-control study including 406 breast cancer patients and 412 controls was conducted and genes Clock (rs2070062) and Per2 (rs2304672, rs2304669, rs934945) were genotyped by TaqMan real-time PCR. Unconditional logistic regression model was used to analyze the association between the genetic polymorphisms and breast cancer.

RESULTSIndividuals with the rs2304669-TT genotype showed significantly increased breast cancer risk with the OR of 2.33 when compared with the individuals with rs2304669-CC and CT genotypes (P = 0.001). In addition, the three haplotypes containing the risk T allele of rs2304669 were identified to be associated with increased breast cancer risk. However, it was found that rs2304672, rs2070062 and rs934945 polymorphisms were not related with breast cancer risk.

CONCLUSIONSThe locus rs2304669 on Per2 gene is associated with breast cancer risk. Genetic variation of circadian clock genes may increase the susceptibility to breast cancer. Therefore, it may become an important biomarker of susceptibility to breast cancer.

Adult ; Biomarkers, Tumor ; genetics ; Breast Neoplasms ; genetics ; CLOCK Proteins ; genetics ; Carcinoma, Ductal, Breast ; genetics ; Case-Control Studies ; Female ; Genetic Variation ; Humans ; Period Circadian Proteins ; genetics ; Polymorphism, Single Nucleotide ; Risk Factors

OBJECTIVETo identify protein-protein interaction partners of PER1 (period circadian protein homolog 1), key component of the molecular oscillation system of the circadian rhythm in tumors using bacterial two-hybrid system technique.

METHODSHuman cervical carcinoma cell Hela library was adopted. Recombinant bait plasmid pBT-PER1 and pTRG cDNA plasmid library were cotransformed into the two-hybrid system reporter strain cultured in a special selective medium. Target clones were screened. After isolating the positive clones, the target clones were sequenced and analyzed.

RESULTSFourteen protein coding genes were identified, 4 of which were found to contain whole coding regions of genes, which included optic atrophy 3 protein (OPA3) associated with mitochondrial dynamics and homo sapiens cutA divalent cation tolerance homolog of E. coli (CUTA) associated with copper metabolism. There were also cellular events related proteins and proteins which are involved in biochemical reaction and signal transduction-related proteins.

CONCLUSIONIdentification of potential interacting proteins with PER1 in tumors may provide us new insights into the functions of the circadian clock protein PER1 during tumorigenesis.

Base Sequence ; Cell Line, Tumor ; Escherichia coli ; genetics ; metabolism ; Humans ; Molecular Sequence Data ; Neoplasms ; genetics ; metabolism ; Period Circadian Proteins ; genetics ; metabolism ; Protein Binding ; Proteins ; genetics ; metabolism ; Two-Hybrid System Techniques

OBJECTIVETo detect the expression of Per2 in non-small cell lung cancer (NSCLC), and analyze its clinical significance.

METHODSThe expression of Per2 was determined in 60 NSCLC and 20 normal lung tissues by immunohistochemical assay, and the relationship between Per2 expression and clinicopathological features was analyzed.

RESULTSThe positive expression rates of Per2 in NSCLC and normal lung tissues were 71.7% and 95.0%, respectively (P < 0.05). The expression of Per2 in NSCLC was correlated with pathological differentiation and TNM stage (P < 0.05).

CONCLUSIONThe expression of Per2 in NSCLC is decreased. The negative expression of Per2 may contribute to the development and invasion in NSCLC.

Adult ; Aged ; Carcinoma, Non-Small-Cell Lung ; metabolism ; pathology ; surgery ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Lung Neoplasms ; metabolism ; pathology ; surgery ; Lymphatic Metastasis ; Male ; Middle Aged ; Neoplasm Grading ; Neoplasm Staging ; Period Circadian Proteins ; metabolism ; Smoking

OBJECTIVETo investigate the clinical significance of promoter methylation status of hPer3 gene in acute myeloid leukemia (AML) patients and the in vitro effect of decitabine (DCA) on AML cell lines HL-60 and U937.

METHODSThe promoter methylation status of hPer3 gene and mRNA expression levels in bone marrow of 206 AML and 40 iron deficiency anemia (IDA) patients (as control) were detected by methylation specific PCR (MS-PCR) and real-time PCR (RT-PCR). The HL-60 and U937 cell lines were treated with different concentrations of DCA for 48 and 72 h. The inhibition rates of cell proliferation were detected by methyl thiazolyl tetrazolium (MTT); the early apoptosis rates by staining with Annexin V and PI; the CD14 and CD11b expressions by flow cytometry (FCM); the promoter methylation status of hPer3 gene by MS-PCR; and the hPer3 mRNA expressions levels by RT-PCR.

RESULTSThe promoter methylation rates of hPer3 in newly diagnosed (ND) group, partial remission(PR) group, complete remission (CR) group, relapse (R) group and control group were 93.65% (59/63), 54.39% (31/57), 24.66% (18/73), 61.54% (8/13) and 0% (0/40), and the hPer3 mRNA expression levels were 0.19 ± 0.08, 6.28 ± 2.11, 52.76 ± 14.17, 8.18 ± 4.36, 75.03 ± 18.16, respectively. There was a significant statistic difference between any two group (P < 0.01) excepting for between PR and R group (P > 0.05). After DCA treatment, the promoter hypermethylation status of hPer3 was reduced and the mRNA and CD14, CD11b expression levels were up regulated in a dose dependent manner with an induction of cell apoptosis.

CONCLUSIONSPromotor methylation status and mRNA expression of hPer3 gene may be indicators for evaluating AML. DCA can induce the expression of hPer3 gene and cells apoptosis in AML.

Adolescent ; Adult ; Aged ; Azacitidine ; analogs & derivatives ; pharmacology ; Cell Proliferation ; DNA Methylation ; Female ; HL-60 Cells ; Humans ; Leukemia, Myeloid, Acute ; genetics ; metabolism ; pathology ; Male ; Middle Aged ; Period Circadian Proteins ; genetics ; Promoter Regions, Genetic ; U937 Cells ; Young Adult

OBJECTIVETo investigate the effect of acute heat stress on the day-night circadian gene Per2 mRNA expression in the liver of rats.

METHODSMale Wistar rats were randomly divided into two groups and exposed to heat at 32 degrees celsius; or to a room temperature at 24 degrees celsius; (control). After 7 days of heat exposure, the body temperature was measured by telemetry. The relative weight of the pituitary and adrenal glands was determined after the exposure, and liver Per2 mRNA expression level was detected using RT-PCR.

RESULTSAcute heat stress did not obviously affect body temperature or body weight of the rats. Seven days of heat exposure increased the relative weight of the pituitary and adrenal glands and significantly lowered Per2 mRNA expression level at night.

CONCLUSIONAcute heat stress can interfere with the day-night circadian gene Per2 mRNA expression in rats.

Adrenal Glands ; Animals ; Body Temperature ; Body Weight ; Heat-Shock Response ; genetics ; Liver ; metabolism ; Male ; Organ Size ; Period Circadian Proteins ; genetics ; metabolism ; Pituitary Gland ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Wistar

OBJECTIVETo investigate the expression and circadian rhythm variation of biological clock gene Per1 and cell cycle genes p53, CyclinD1, cyclin-dependent kinases (CDK1), CyclinB1 in different stages of carcinogenesis in buccal mucosa and its relationship with the development of buccal mucosa carcinoma.

METHODSNinety golden hamsters were housed under 12 hours light-12 hours dark cycles, and the model of buccal squamous cell carcinoma was established by using the dimethylbenzanthracene (DMBA) to smear the golden hamster buccal mucosa. Before the DMBA was used and after DMBA was used 6 weeks and 14 weeks respectively, the golden hamsters were sacrificed at 6 different time points (5 rats per time point) within 24 hour, including 4, 8, 12, 16, 20 and 24 hour after lights onset (HALO), and the normal buccal mucosa, precancerous lesions and cancer tissue were obtained, respectively. HE stained sections were prepared to observe the canceration of each tissue. Real time RT-PCR was used to detect the mRNA expression of Per1, p53, CyclinD1, CDK1 and CyclinB1, and a cosine analysis method was applied to determine the circadian rhythm variation of Per1, p53, CyclinD1, CDK1 and CyclinB1 mRNA expression, which were characterized by median, amplitude and acrophase.

RESULTSThe expression of Per1, p53, CDK1 and CyclinD1 mRNA in 6 different time points within 24 hours in the tissues of three different stages of carcinogenesis had circadian rhythm, respectively. However, the CyclinB1 mRNA was expressed with circadian rhythm just in normal and cancer tissue (P < 0.05), while in precancerous lesions the circadian rhythm was in disorder (P > 0.05). As the development of carcinoma, the median of Per1 and p53 mRNA expression were significantly decreased (P < 0.05), yet the median of CDK1, CyclinB1 and CyclinD1 mRNA expression were significantly increased (P < 0.05). The amplitude of Per1, p53 and CyclinD1 mRNA expression was significantly decreased as the development of carcinoma (P < 0.05), however the amplitude of CDK1 mRNA expression was significantly increased (P < 0.05). In addition, there was no significant difference in the amplitude of CyclinB1 mRNA expression. The time that the peak expression value of Per1 and CDK1 mRNA appeared (Acrophase) in precancerous lesions was remarkably earlier than that in normal tissues, but the acrophase of p53 and CyclinD1 mRNA expression was remarkably delayed. Moreover, the acrophase of CDK1 and CyclinB1 mRNA expression in cancer tissues was obviously earlier than that in normal tissues, yet there was no significant variation in acrophase of Per1, p53, CyclinD1 mRNA expression between normal tissues and cancer tissues.

CONCLUSIONSThe circadian rhythm of clock gene Per1 and cell cycle genes p53, CyclinD1, CDK1, CyclinB1 expression remarkably varied with the occurrence and development of carcinoma. Further research into the interaction between circadian and cell cycle of two cycle activity and relationship with the carcinogenesis may providenew ideas and methods of individual treatment and the mechanism of carcinogenesis.

9,10-Dimethyl-1,2-benzanthracene ; Animals ; CDC2 Protein Kinase ; genetics ; Carcinogenesis ; Carcinogens ; Carcinoma, Squamous Cell ; chemically induced ; genetics ; pathology ; Cell Cycle ; Circadian Rhythm ; genetics ; Cricetinae ; Cyclin B1 ; genetics ; Disease Models, Animal ; Gene Expression Regulation, Neoplastic ; Genes, bcl-1 ; Genes, p53 ; Mesocricetus ; Mouth Mucosa ; Mouth Neoplasms ; chemically induced ; genetics ; pathology ; Period Circadian Proteins ; genetics ; Precancerous Conditions ; genetics ; RNA, Messenger ; metabolism ; Rats ; Real-Time Polymerase Chain Reaction ; Time Factors