Interleukin-6 (IL-6) -174G/C genomic polymorphism contribution to the risk of coronary artery disease in a Chinese population

To investigate the role of IL-6 polymorphism (-174G/C and -572C/G) in the development of coronary artery disease (CAD), CAD patients (224) and control subjects (260) were recruited between January 2012 and December 2014. Genotyping at IL-6 -174G/C and -572C/G was conducted via polymerase chain reaction coupled to restriction fragment length polymorphism. Results indicated that several disease risk factors were significantly higher in CAD patients as compared to the control subjects. These factors include hypertension (χ2 = 20.03, P < 0.001), diabetes mellitus (χ(2) = 33.53, P < 0.001), tobacco smoking (χ(2) = 28.17, P < 0.001), body mass indexes (t = 11.39, P < 0.001), total cholesterol (t = 8.25, P < 0.001), low-density lipoprotein cholesterol (t = 7.24, P < 0.001), high-density lipoprotein cholesterol (t = 3.52, P < 0.001), and triglyceride (t = 6.09, P < 0.001). By unconditional logistic regression analysis, we observed that the CC genotype at IL-6 -174G/C was had a 2.32 (95%CI = 1.33-4.06) fold risk of developing CAD compared to the GG genotype. Moreover, IL-6 -174G/C polymorphism was positively associated with the risk of developing CAD in both dominant (OR = 1.63, 95%CI = 1.12-2.38; P = 0.01) and recessive models (OR = 2.18, 95%CI = 1.26-3.77; P = 0.001). However, no statistically significant association was observed between IL-6 -572C/G polymorphism and risk of CAD. In conclusion, IL-6 -174G/C polymorphisms are associated with the pathogenesis of CAD.

Brain substrates of perceived spatial separation between speech sources under simulated reverberant listening conditions in schizophrenia

BACKGROUND

People with schizophrenia recognize speech poorly under multiple-people-talking (informational masking) conditions. In reverberant environments, direct-wave signals from a speech source are perceptually integrated with the source reflections (the precedence effect), forming perceived spatial separation (PSS) between different sources and consequently improving target-speech recognition against informational masking. However, the brain substrates underlying the schizophrenia-related vulnerability to informational masking and whether schizophrenia affects the unmasking effect of PSS are largely unknown.

METHOD

Using psychoacoustic testing and functional magnetic resonance imaging, respectively, the speech recognition under either the PSS or perceived spatial co-location (PSC) condition and the underlying brain substrates were examined in 20 patients with schizophrenia and 16 healthy controls.

RESULTS

Speech recognition was worse in patients than controls. Under the PSS (but not PSC) condition, speech recognition was correlated with activation of the superior parietal lobule (SPL), and target speech-induced activation of the SPL, precuneus, middle cingulate cortex and caudate significantly declined in patients. Moreover, the separation (PSS)-against-co-location (PSC) contrast revealed (1) activation of the SPL, precuneus and anterior cingulate cortex in controls, (2) suppression of the SPL and precuneus in patients, (3) activation of the pars triangularis of the inferior frontal gyrus and middle frontal gyrus in both controls and patients, (4) activation of the medial superior frontal gyrus in patients, and (5) impaired functional connectivity of the SPL in patients.

CONCLUSIONS

Introducing the PSS listening condition efficiently reveals both the brain substrates underlying schizophrenia-related speech-recognition deficits against informational masking and the schizophrenia-related neural compensatory strategy for impaired SPL functions.

Extracorporeal hepatic resection and autotransplantation for primary gastrointestinal stromal tumor of the liver

We report a case of primary gastrointestinal stromal tumor of the liver. A 60-year-old woman with a large mass in the liver was asymptomatic with no hepatic virus infection and negative tumor markers. Because the tumor was unresectable by conventional means, we used extracorporeal hepatic resection and autotransplantation (ECHRA) for operation. The pathology showed a gastrointestinal stromal tumor that was diagnosed based on positive immunostaining for c-kit and CD34. Mutation analysis revealed an acquired mutation in exon 11 of c-kit. As we know, this is the eighth case of a primary hepatic extragastrointestinal stromal tumor reported previously in English, and the first case of which that was treated with ECHRA.

Correlation between polymorphisms in the IL-17A and IL-17F genes and development of coronary artery disease

A case-control study was conducted to investigate the association between genetic variants of IL-17A rs2275913 and IL-17F rs763780 and the development of coronary artery disease (CAD) in a Chinese population. A total of 306 individuals with CAD and 306 unaffected individuals were enrolled from the Zhengzhou People's Hospital between May 2012 and May 2014. The IL-17A rs2275913 and IL-17F rs763780 genes were genotyped by polymerase chain reaction combined with a restriction fragment length polymorphism (PCR-RFLP). Logistic regression analysis revealed that individuals with the AA genotype of rs2275913 were associated with increased risk of CAD, compared to those with the GG genotype in a codominant model [adjusted odds ratio (OR) = 1.96; 95% confidence interval (CI) = 1.10-3.53]. On the other hand, the AA genotype of rs2275913 was correlated with moderately increased risk of CAD compared to the GG + GA genotype (adjusted OR = 1.76; 95%CI = 1.02-3.07) in a recessive model. However, no significant differences were observed between polymorphisms at the IL-17F rs763780 locus and CAD risk, in codominant, dominant, and recessive models. In conclusion, the results of our study suggested that the IL-17A rs2275913 polymorphism may affect the development of CAD; however, no significant association was observed between the IL-17F rs763780 polymorphism and risk of CAD.

Hospitalisation rates and associated factors in community-based cohorts of HIV-infected and -uninfected gay and bisexual men

OBJECTIVES

There is evidence that HIV-positive patients are suffering from a greater burden of morbidity as they age due to nonAIDS-related complications. To date it has been difficult to determine what part of this excess risk is due to the health effects of HIV, its treatment or to lifestyle factors common to gay and bisexual men (GBM). We calculated overall and cause-specific hospitalisation rates and risk factors for hospitalisations in HIV-negative and HIV-positive cohorts of GBM and compare these with rates in the general male population.

METHODS

We conducted a record linkage study, linking two cohorts of HIV-negative (n = 1325) and HIV-positive (n = 557) GBM recruited in Sydney, New South Wales (NSW), Australia with the NSW hospital discharge data register. We compared rates of hospitalisation in the two cohorts and risk factors for hospitalisation using random-effects Poisson regression methods. Hospitalisation rates for each cohort were further compared with those in the general male population using indirect standardisation.

RESULTS

We observed 2032 hospitalisations in the HIV-negative cohort during 13,016 person-years (PYs) [crude rate: 15.6/100 PYs (95% CI: 14.9-16.3)] and 2130 hospitalisations in the HIV-positive cohort during 5571 PYs [crude rate: 38.2/100 PYs (95% CI: 36.6-39.9)]. HIV-positive individuals had an increased risk of hospitalisation compared with the HIV-negative individuals [adjusted-IRR: 2.34 (95% CI: 1.91-2.86)] and the general population [SHR: 1.45 (95% CI: 1.33-1.59)]. Hospitalisation rates were lower in the HIV-negative cohort compared with the general population [SHR: 0.72 (95% CI: 0.67-0.78)]. The primary causes of hospitalisation differed between groups.

CONCLUSIONS

HIV-positive GBM continue to experience excess morbidity compared with HIV-negative GBM men and the general population. HIV-negative GBM had lower morbidity compared with the general male population suggesting that GBM identity does not confer excess risk.

Understanding Concerns About Treatment-as-Prevention Among People with HIV who are not Using Antiretroviral Therapy

The use of antiretroviral therapy to prevent HIV transmission is now advocated in many settings, yet little research has documented the views of people with HIV. Semi-structured interviews were conducted in Australia between 2012 and 2014 with 27 HIV-positive people not using treatment at the time of interview. Thematic analysis of views on treatment-as-prevention found that while many participants recognised potential prevention benefits, only a minority was in support of initiating treatment solely to achieve those benefits. A range of uncertain or critical views were expressed regarding who would benefit, risk reduction, and changing treatment norms. Participants resisted responsibility narratives that implied treatment should be used for the public good, in favour of making considered decisions about their preferred approach to managing HIV. Engaging communities in dialogue and debate regarding the risks and benefits of treatment will be critical if this new prevention strategy is to engender public trust.

Graphene-based photocatalysts for oxygen evolution from water

Recent achievements of GR-based photocatalysts for oxygen evolution from water are summarized with perspectives on major challenges and opportunities.

Le traitement mensuel par palmitate de paliperidone (PP) versus les traitements antipsychotiques oraux journaliers retarde les conséquences négatives de la schizophrénie en « vie réelle » (étude PRIDE)

Objectifs

Un échec de traitement peut entraîner diverses conséquences à la fois pour le patient souffrant de schizophrénie mais aussi en terme de santé publique (arrêt du traitement, hospitalisation, addiction, arrestation/incarcération) [1–3]. Cette étude a comparé en vraie vie, les délais avant échec au traitement des patients souffrant de schizophrénie ayant des antécédents d’incarcération, traités soit par palmitate de paliperidone (PP) ou par des antipsychotiques oraux (APO).

Méthodes

Paliperidone Research In Demonstrating Effectiveness (PRIDE) est une étude en ouvert, prospective, randomisée, d’une durée de 15 mois, comparant le PP une fois par mois aux APO chez des sujets atteints de schizophrénie, avec des antécédents d’incarcération (NCT01157351). Les sujets ont été randomisés (1:1) en deux groupes :

– PP à doses flexibles (78–234 mg) administrées une fois par mois ou à ;

– l’un des 7 APO couramment prescrits par l’investigateur.

Le critère de jugement principal était le délai avant échec du traitement (défini comme arrestation/incarcération, hospitalisation, suicide, arrêt du traitement ou supplémentation par manque d’efficacité ou mauvaise tolérance et/ou besoin d’intensifier les soins psychiatriques) évalué par la méthode de Kaplan-Meier.

Résultats

Un total de 450 sujets ont été inclus (sexe masculin = 86,3 %). Le délai avant échec du traitement était significativement plus long avec le PP par rapport aux APO (médiane = 416 vs 226 jours avant arrêt du traitement ou supplémentation ; Rapport de risque [IC95 %] = 1,43 [1,09, 1,88] ; p = 0,011). Les taux d’échecs du traitement étaient de 39,8 % avec le PP et de 53,7 % avec les APO. Des résultats similaires ont été observés pour le délai avant hospitalisation ou arrestation/incarcération (médiane ≥ 450 vs 274 jours ; rapport de risque [IC95 %] = 1,43 [1,06, 1,93] ; p = 0,019). Les événements indésirables les plus fréquents (PP vs APO, ≥ 10 %) étaient : douleur au site d’injection (18,6 % vs 0 %) ; insomnie (16,8 % vs 11,5 %) ; prise de poids (11,9 % vs 6,0 %) ; akathisie (11,1 % vs 6,9 %) ; anxiété (10,6 % vs 7,3 %).

Conclusion

Le traitement mensuel par PP injectable retarde significativement le délai de survenue d’un large éventail de conséquences négatives de la schizophrénie en vie réelle.

Younger age, recent HIV diagnosis, no welfare support and no annual sexually transmissible infection screening are associated with nonuse of antiretroviral therapy among HIV-positive gay men in Australia

OBJECTIVES

With the increasing momentum to maximize the benefits of antiretroviral therapy (ART), better understanding of opportunities and challenges in increasing ART coverage and promoting early ART initiation is urgently needed. Key sociodemographic, clinical and behavioural factors associated with Australian HIV-positive gay men's current nonuse of ART were systematically examined.

METHODS

Data were based on 1911 responses from HIV-positive men who had participated in the Australian Gay Community Periodic Surveys (GCPS) between 2010 and 2012. Stratified univariate analysis and multivariate logistic regression were used.

RESULTS

A majority of the participants were recruited from gay community venues and events and self-identified as gay or homosexual. On average, they were 44 years old and had been living with HIV for at least 10 years. Close to 80% (n=1555) were taking ART, with >90% further reporting an undetectable viral load at the time of the survey. From 2010 to 2012, there had been a moderate increase in ART uptake [adjusted odds ratio (AOR) 1.40; 95% confidence interval (CI) 1.20-1.65]. In addition, younger age (AOR 1.66; 95% CI 1.45-1.92), recent HIV diagnosis (AOR 1.78; 95% CI 1.59-1.98), not receiving any social welfare payments (AOR 2.20; 95% CI 1.05-2.54) and no annual screening for sexually transmissible infections (AOR 1.55; 95% CI 1.03-2.34) were independently associated with ART nonuse.

CONCLUSIONS

Current ART coverage among HIV-positive gay men in Australia is reasonably high. To further increase ART coverage and promote early ART initiation in this population, better clinical care and sustained structural support are needed for HIV management throughout their life course.

Comprehensive biomarker analysis and final efficacy results of sorafenib in the BATTLE trial

PURPOSE

To report the clinical efficacy of sorafenib and to evaluate biomarkers associated with sorafenib clinical benefit in the BATTLE (Biomarker-Integrated Approaches of Targeted Therapy for Lung Cancer Elimination) program.

PATIENTS AND METHODS

Patients with previously treated non-small cell lung cancer (NSCLC) received sorafenib until progression or unacceptable toxicity. Eight-week disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) were assessed. Prespecified biomarkers included K-RAS, EGFR, and B-RAF mutations, and EGFR gene copy number. Gene expression profiles from NSCLC cell lines and patient tumor biopsies with wild-type EGFR were used to develop a sorafenib sensitivity signature (SSS).

RESULTS

A total of 105 patients were eligible and randomized to receive sorafenib. Among 98 patients evaluable for eight-week DCR, the observed DCR was 58.2%. The median PFS and OS were 2.83 [95% confidence interval (CI), 2.04-3.58] and 8.48 months (95% CI, 5.78-10.97), respectively. Eight-week DCR was higher in patients with wild-type EGFR than patients with EGFR mutation (P = 0.012), and in patients with EGFR gene copy number gain (FISH-positive) versus patients FISH-negative (P = 0.048). In wild-type EGFR tumors, the SSS was associated with improved PFS (median PFS 3.61 months in high SSS vs. 1.84 months in low SSS; P = 0.026) but not with eight-week DCR. Increased expression of fibroblast growth factor-1, NF-κB, and hypoxia pathways were identified potential drivers of sorafenib resistance.

CONCLUSION

Sorafenib demonstrates clinical activity in NSCLC, especially with wild-type EGFR. SSS was associated with improved PFS. These data identify subgroups that may derive clinical benefit from sorafenib and merit investigation in future trials.

Serum biomarkers and the prognosis of AMI patients

BACKGROUND

It has been proven that serum lactate dehydrogenase (LDH) and total bilirubin (TB) increase during acute myocardial infarction (AMI). However, how they influence the prognosis of AMI patients is still not completely known.

METHODS

A total of 239 patients diagnosed with AMI and admitted to the Fourth Clinical Hospital of Harbin Medical University, between 2007 and 2008, were enrolled in this study. All the patients had not undergone primary percutaneous coronary intervention (PCI) because the time window (24 h) was missed. They all underwent PCI 1 week after the onset of symptoms. Serum high-sensitivity C-reactive protein (hs-CRP), TB, LDH, and other biomarkers were determined between 24 and 48 h of symptom onset. All of the patients were followed up for an average of 3.2±0.4 years for occurrence of major adverse cardiac events (MACE).

RESULTS

Patients with MACE had significantly higher levels of hs-CRP, LDH, cystatin C, uric acid, a higher ratio of LDH and TB (LDH/TB), and a lower level of TB: 8.48±3.84 vs. 2.13±1.32 μmol/l, p<0.01; 1,355.8±654.3 vs. 1,151.7±415.4 U/l, p<0.01; 1.69±0.76 vs. 1.00±0.46 mg/l, p<0.01; 419.6±109.2 vs. 343.2±108.2 μmol/l, p<0.01 and 141.1±46.2 vs. 61.2±26.5, p<0.01; 18.3±6.7 vs. 14.8±6.6 mg/l, p<0.01, respectively. In the multivariate COX analysis, LDH, cystatin C, and LDH/TB were significantly associated with the prognosis of these patients.

CONCLUSIONS

Patients under higher oxidative stress tend to have more MACE. LDH, cystatin C, and LDH/TB are strongly related to the prognosis of AMI patients undergoing elective PCI.

Effects of degradable MG-ND-ZN-ZR alloy on osteoblastic cell function

This study aimed to investigate the effects of a novel patented Mg-3Nd-0.2Zn-0.4Zr (weight %, JDBM) alloy on osteoblastic cell function, as these cells play an important role in bone repair and remodeling. The associated effects of the JDBM alloy on osteoblastic cell function involving cell adhesion, cell proliferation, and mineralization were investigated using scanning electron microscopy (SEM), MTT assay and ambramycin staining, respectively. At the same time, the in vitro degradation behavior of the JDBM alloy in cell culture medium was evaluated by the weight-loss method and SEM. Pure magnesium was used as control. The results showed that osteoblastic cells cultured on JDBM alloy samples manifested better cell adhesion, improved cell proliferation and increased mineralization ability, compared with cells seeded on pure magnesium samples. Our data indicate that the JDBM alloy has excellent bioactivity, improving the cell function of osteoblastic cells seeded on it.

Delayed administration of a PTEN inhibitor BPV improves functional recovery after experimental stroke

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) inhibitors administered prior to or immediately after experimental stroke confer acute neuroprotection. However, it remains unclear if delayed treatment with a PTEN inhibitor improves long-term functional recovery after stroke. We addressed the issue in this study. Adult male mice were subjected to 1h of middle cerebral artery occlusion (MCAO) followed by treatment with a well-established PTEN inhibitor BPV or saline daily for 14 days, starting at 24h after MCAO. Functional recovery was assessed with behavioral tests and acute infarct volumes were analyzed histologically. Delayed BPV treatment did not reduce infarction during the acute phase, but significantly improved long-term functional recovery after MCAO. Since PTEN is a critical intrinsic inhibitory factor in axonal regeneration, we further examined BPV effects on axonal densities following MCAO using bielschowsky silver staining and immunohistochemistry with antibodies against myelin basic protein. Delayed BPV treatment significantly increased axon densities in the ischemic brain at 14 days after MCAO. Moreover, PTEN expression persistently remained high in the ischemic brain over 14 days after MCAO, and BPV treatment increased post-ischemic activation of Akt and mTOR in the ischemic brain. Akt and mTOR activation are the well-established cascades downstream to PTEN inhibition and have been shown to contribute to post-injury axonal regrowth in response to PTEN inhibition. Consistently, in an in vitro neuronal ischemia model, BPV enhanced axonal outgrowth of primary cortical neurons after oxygen-glucose deprivation and the enhancing effects were abolished by Akt/mTOR inhibition. In conclusion, delayed BPV treatment improved functional recovery from experimental stroke possibly via enhancing axonal growth and Akt/mTOR activation contributed to BPV-enhanced post-stroke axon growth.

Stopped-flow spectrophotometric determination of hydrogen peroxide with hemoglobin as catalyst

A rapid and sensitive method was proposed for the determination of hydrogen peroxide based on the catalytic effect of hemoglobin using o-phenylenediamine as the substrate. Stopped-flow spectrophotometric method was used to study the kinetic behavior of the oxidation reaction. The catalytic effectiveness of hemoglobin was compared with other four kinds of catalysts. The initial rate of the formation of the reaction product 2,3-diaminophenazine at the wavelength of 425 nm was monitored, permitting a detection limit of 9.2x10(-9) mol/l H(2)O(2). A linear calibration graph was obtained over the H(2)O(2) concentration range 5.0x10(-8)-3.5x10(-6) mol/l, and the relative standard deviation at a H(2)O(2) concentration of 5.0x10(-7) mol/l was 2.08%. Satisfied results were obtained in the determination of H(2)O(2) in real samples by this method.

A novel thin-layer amperometric detector based on chemically modified ring-disc electrode and its application for simultaneous measurements of nitric oxide and nitrite in rat brain combined with in vivo microdialysis

A novel thin-layer amperometric detector (TLAD) based on chemically modified ring-disc electrode and its application for simultaneous measurements of nitric oxide (NO) and nitrite (NO(2)(-)) in rat brain were demonstrated in this work. The ring-disc electrode was simultaneously sensitive to nitric oxide (NO) and nitrite (NO(2)(-)) by modifying its inner disc with electropolymerized film of cobalt(II) tetraaminophthalocyanine (polyCoTAPc)/Nafion and its outer ring with poly(vinylpyridine) (PVP), respectively. The ring-disc electrode was used to constitute a novel TLAD in radial flow cell for simultaneous measurements of NO and NO(2)(-) in rat brain combined with techniques of high performance liquid chromatography (HPLC) and in vivo microdialysis. It was found that the basal concentration of NO in the caudate nucleus of rat brain is lower than 1.0x10(-7) mol l(-1), NO(2)(-) concentration is 5.0x10(-7) mol l(-1) and NO exists in brain maybe mainly in the form of its decomposed product.

RFLP analysis of the progeny from Oryza alta Swallen x Oryza sativa L

RFLP analyses were carried out in the progeny from a cross of two phylogenetically distant rice species, wild rice Oryza alta Swallen (CCDD, 2n = 48) and cultivated rice O. sativa L. (AA, 2n = 24). The sterile plants gave heterozygous RFLP patterns at most of the loci detected. They looked more like their wild rice parent, with 36 chromosomes in their root-tip cells and pollen mother cells. In two partially fertile plants, however, most of the markers that were used showed RFLP patterns similar to the cultivated parent, O. sativa. By cytological study, it was found that nearly one-third of the chromosomes had been eliminated in the partially fertile plants. Their seeds have short awns, which is a characteristic of their wild parent, O. alta. An introgression occurred in one of the partially fertile plants, which led to the discussion about a nonconventional mechanism in wide hybridization for transference of wild rice chromosome segments to cultivated rice chromosomes.

Gay men who are not getting tested for HIV

Using data from Australian Gay Community Periodic Surveys 1998-2010, we assessed the prevalence, trends and characteristics of gay men not tested for HIV. In 2010, one in eight Australian gay socially-engaged men were never tested for HIV, most of them sexually active and 56.5 % reporting unprotected anal intercourse. The proportion of not tested men was significantly higher in men younger than 30, of non-European origin and living outside of gay metropolitan areas. Although frequency of testing was associated with sexual practices, significant proportions of men with multiple sex partners and reporting unprotected anal intercourse were not tested as recommended. There were issues with using gay-friendly testing services in gay metropolitan areas. Despite Australia's success in HIV testing, improvement is needed for early detection of HIV infections. Interventions should encourage regular testing, engage with young gay men, improve access and convenience of testing, train service providers and expand testing options.

Exendin-4 improved rat cortical neuron survival under oxygen/glucose deprivation through PKA pathway

Previous studies demonstrated that exendin-4 (Ex-4) may possess neurotrophic and neuroprotective functions in ischemia insults, but its mechanism remained unknown. Here, by using real-time PCR and ELISA, we identified the distribution of active GLP-1Rs in the rat primary cortical neurons. After establishment of an in vitro ischemia model by oxygen/glucose deprivation (OGD), neurons were treated with various dosages of Ex-4. The MTT assay showed that the relative survival rate increased with the dosage of Ex-4 ranging from 0.2 to 0.8 μg/ml (P<0.001, vs. OGD group). The apoptosis rate was reduced from (49.47±2.70)% to (14.61±0.81)% after Ex-4 treatment (0.4 μg/ml) 12h after OGD (P<0.001). Moreover, immunofluorescence staining indicated that Ex-4 increased glucose-regulated proteins 78 (GRP78) and reduced C/EBP-homologous protein (CHOP). Western blot analysis demonstrated that, after neurons were treated with Ex-4, GRP78 was up-regulated over time (P<0.01, vs. OGD group), while CHOP levels rose to a peak 8h after OGD and then decreased (P<0.05, vs. OGD group). This effect was changed by both the protein kinase A (PKA) inhibitor H89 (P<0.01, P<0.05, respectively, vs. Ex-4 group) and the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 (P<0.01, P<0.01, respectively, vs. Ex-4 group) but not by the mitogen-activated protein kinase (MAPK) inhibitor U0126. Our study also revealed that, compared with the Ex-4 group, inhibition of the PKA signaling pathway significantly decreased the survival rate of neurons, down-regulated the expression of B-cell lymphoma 2 (Bcl-2) and up-regulated the Bax expression 3h after ODG (P<0.05, P<0.01, respectively), while neither PI3K nor MAPK inhibition exerted such effects. Furthermore, Western blotting exhibited that PKA expression was elevated in the presence or absence of OGD insults (P<0.05). This study indicated that Ex-4 protected neurons against OGD by modulating the unfolded protein response (UPR) through the PKA pathway and may serve as a novel therapeutic agent for stroke.

Oscillation of clock and clock controlled genes induced by serum shock in human breast epithelial and breast cancer cells: regulation by melatonin

This study investigates differences in expression of clock and clock-controlled genes (CCGs) between human breast epithelial and breast cancer cells and breast tumor xenografts in circadian intact rats and examines if the pineal hormone melatonin influences clock gene and CCG expression. Oscillation of clock gene expression was not observed under standard growth conditions in vitro, however, serum shock (50% horse serum for 2 h) induced oscillation of clock gene and CCG expression in MCF-10A cells, which was repressed or disrupted in MCF-7 cells. Melatonin administration following serum shock differentially suppressed or induced clock gene (Bmal1 and Per2) and CCG expression in MCF10A and MCF-7 cells. These studies demonstrate the lack of rhythmic expression of clock genes and CCGs of cells in vitro and that transplantation of breast cancer cells as xenografts into circadian competent hosts re-establishes a circadian rhythm in the peripheral clock genes of tumor cells.