Hyperglycaemia-induced chemoresistance in breast cancer cells: role of the estrogen receptor

Breast cancer patients with diabetes respond less well to chemotherapy; in keeping with this we determined previously that hyperglycaemia-induced chemoresistance in estrogen receptor (ERα) positive breast cancer cells and showed that this was mediated by fatty acid synthase (FASN). More recent evidence suggests that the effect of metabolic syndrome and diabetes is not the same for all subtypes of breast cancer with inferior disease-free survival and worse overall survival only found in women with ERα positive breast cancer and not for other subtypes. Here we examined the impact of hyperglycaemia on ERα negative breast cancer cells and further investigated the mechanism underlying chemoresistance in ERα with a view to identifying strategies to alleviate hyperglycaemia-induced chemoresistance. We found that hyperglycaemia-induced chemoresistance was only observed in ERα breast cancer cells and was dependent upon the expression of ERα as chemoresistance was negated when the ERα was silenced. Hyperglycaemia-induced an increase in activation and nuclear localisation of the ERα that was downstream of FASN and dependent on the activation of MAPK. We found that fulvestrant successfully negated the hyperglycaemia-induced chemoresistance, whereas tamoxifen had no effect. In summary our data suggests that the ERα may be a predictive marker of poor response to chemotherapy in breast cancer patients with diabetes. It further indicates that anti-estrogens could be an effective adjuvant to chemotherapy in such patients and indicates the importance for the personalised management of breast cancer patients with diabetes highlighting the need for clinical trials of tailored chemotherapy for diabetic patients diagnosed with ERα positive breast cancers.

The Global Reciprocal Reprogramming between Mycobacteriophage SWU1 and Mycobacterium Reveals the Molecular Strategy of Subversion and Promotion of Phage Infection

Bacteriophages are the viruses of bacteria, which have contributed extensively to our understanding of life and modern biology. The phage-mediated bacterial growth inhibition represents immense untapped source for novel antimicrobials. Insights into the interaction between mycobacteriophage and Mycobacterium host will inform better utilizing of mycobacteriophage. In this study, RNA sequencing technology (RNA-seq) was used to explore the global response of Mycobacterium smegmatis mc²155 at an early phase of infection with mycobacteriophage SWU1, key host metabolic processes of M. smegmatis mc²155 shut off by SWU1, and the responsible phage proteins. The results of RNA-seq were confirmed by Real-time PCR and functional assay. 1174 genes of M. smegmatis mc²155 (16.9% of the entire encoding capacity) were differentially regulated by phage infection. These genes belong to six functional categories: (i) signal transduction, (ii) cell energetics, (iii) cell wall biosynthesis, (iv) DNA, RNA, and protein biosynthesis, (v) iron uptake, (vi) central metabolism. The transcription patterns of phage SWU1 were also characterized. This study provided the first global glimpse of the reciprocal reprogramming between the mycobacteriophage and Mycobacterium host.

Phage DNA dynamics in cells with different fates

Bacteriophage λ begins its infection cycle by ejecting its DNA into its host Escherichia coli cell, after which either a lytic or a lysogenic pathway is followed, resulting in different cell fates. In this study, using a new technique to monitor the spatiotemporal dynamics of the phage DNA in vivo, we found that the phage DNA moves via two distinct modes, localized motion and motion spanning the whole cell. One or the other motion is preferred, depending on where the phage DNA is ejected into the cell. By examining the phage DNA trajectories, we found the motion to be subdiffusive. Moreover, phage DNA motion is the same in the early phase of the infection cycle, irrespective of whether the lytic or lysogenic pathway is followed; hence, cell-fate decision-making appears not to be correlated with the phage DNA motion. However, after the cell commits to one pathway or the other, phage DNA movement slows during the late phase of the lytic cycle, whereas it remains the same during the entire lysogenic cycle. Throughout the infection cycle, phage DNA prefers the regions around the quarter positions of the cell.

Small heat shock proteins and the endoplasmic reticulum: potential attractive therapeutic targets?

The endoplasmic reticulum(ER) is crucial for protein and lipid synthesis, folding and cellular homeostasis. Function impairment of ER would induce ER stress, which might play an important role in many different pathological states. Small heat shock proteins (sHsps) are known to be widely expressed throughout many tissues. SHsps are found to regulate many different pathological and pathophysiological processes and they are supposed to be potential therapeutic targets. Recent studies indicate that multiple sHsps localize to the mammalian and plant ER and sHsps confer protection against ER stress in multiple cellular processes. The mechanisms responsible for the cytoprotective effects of sHsps are related to maintaining ER homeostasis. Improved understanding of sHsps-related cytoprotective action on ER and successful strategies which could specifically target components of ER stress signalling responses amelioration of their toxic effects by sHsps is of great importance in the development of therapeutic approach for the disorders induced by dysfunction of ER.

Aberrant IDH3α expression promotes malignant tumor growth by inducing HIF-1-mediated metabolic reprogramming and angiogenesis

Cancer cells gain a growth advantage through the so-called Warburg effect by shifting glucose metabolism from oxidative phosphorylation to aerobic glycolysis. Hypoxia-inducible factor 1 (HIF-1) has been suggested to function in metabolic reprogramming; however, the underlying mechanism has not been fully elucidated. We found that the aberrant expression of wild-type isocitrate dehydrogenase 3α (IDH3α), a subunit of the IDH3 heterotetramer, decreased α-ketoglutarate levels and increased the stability and transactivation activity of HIF-1α in cancer cells. The silencing of IDH3α significantly delayed tumor growth by suppressing the HIF-1-mediated Warburg effect and angiogenesis. IDH3α expression was associated with the poor postoperative overall survival of lung and breast cancer patients. These results justify the exploitation of IDH3 as a novel target for the diagnosis and treatment of cancers.

Evaluation of socio-economic inequalities in the use of maternal health services in rural western China

OBJECTIVES

To describe the use of maternal health services according to the standards of the Chinese Ministry of Health, and assess socio-economic inequalities in usage in rural Shaanxi province, western China.

STUDY DESIGN

Cross-sectional survey.

METHODS

Principal components analysis was used to measure the economic status of households. A concentration index (CI) approach was used as a measure of socio-economic inequalities in the use of maternal health services, and a decomposable CI was used to identify the factors that contributed to the socio-economic inequalities in usage.

RESULTS

In total, 4760 women who had given birth in the preceding three years were selected at random to be interviewed in the five counties. Household wealth index was calculated by constructing a linear index from asset ownership indicators using principal components analysis to derive weights. The CI approach is a standard measure in the analysis of inequalities in health. If the CI for the use of maternal health services is positive, it is pro-rich; if it is negative, it is pro-poor. The decomposition method was used to estimate the contributions of individual factors to CI. The overall CI for five or more prenatal visits was 0.075. The household wealth index was found to make the greatest contribution to socio-economic inequalities for five or more prenatal visits (35.5%), followed by maternal education (28.8%), receipt of a health handbook during pregnancy (12.1%), age group (11.0%), distance from health facility (10.5%), family members (1.5%) and district of residence (0.6%).

CONCLUSIONS

Socio-economic inequalities in the use of prenatal health services were pro-rich in rural western China. Socio-economic inequalities in hospital delivery and postnatal health check-ups were not evident. Improving household economic status, providing prenatal health services for women with low income and low educational level, providing health handbooks and improving traffic conditions should be promoted as methods to eliminate socio-economic inequalities in the use of maternal health services.

Evolving concepts of chondrogenic differentiation: history, state-of-the-art and future perspectives

As a cell source, multipotent mesenchymal stromal cells or mesenchymal stem cells (MSCs) are promising candidates for chondrogenic differentiation and subsequent cartilage regeneration. From previous literature, it is known that chondrogenic differentiation of MSCs inevitably leads to hypertrophy and subsequent endochondral ossification. In this review, we examine the history of currently established protocols of chondrogenic differentiation and elaborate on the roles of individual components of chondrogenic differentiation medium. We also summarise the effects of physical, chemical and biological factors involved, and propose potential strategies to differentiate MSCs into articular chondrocytes with homogenous mature phenotypes through spatial-temporal incorporation of cell differentiation and chondrogenesis.

Variation in maternal urinary cortisol profiles across the peri-conceptional period: a longitudinal description and evaluation of potential functions

STUDY QUESTION

How do women's first morning urinary cortisol levels, a marker of stress axis activity, vary during the peri-conceptional period (the 12 weeks around conception)?

SUMMARY ANSWER

First morning urinary cortisol follows an overall increasing trajectory across the peri-conceptional period, interrupted by 2 week-long decreases during the week preceding conception and the fifth week following conception.

WHAT IS KNOWN ALREADY

Later gestational stages (i.e. second and third trimesters) are characterized by increasing levels of circulating cortisol. This increase is hypothesized to constitute a response to the energy demands imposed by fetal growth, and the development of energy reserves in preparation for nursing and performing regular activities while carrying pregnancy's extra weight and volume.

STUDY DESIGN, SIZE, DURATION

This study is based on a data set collected as part of a longitudinal, naturalistic investigation into the interactions between the stress (hypothalamic-pituitary-adrenal axis (HPAA)) and reproductive (hypothalamic-pituitary-gonadal axis (HPGA)) axes. Biomarkers of HPAA and HPGA function were quantified in first morning urinary specimens collected every other day from 22 healthy women who conceived a pregnancy during the study. We analyzed the longitudinal within- and between-individual variation in first morning urinary cortisol levels across the 12-week peri-conceptional period.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants were recruited from two rural, aboriginal, neighboring communities in Guatemala. Cortisol, estradiol and progesterone metabolites (estrone-3-glucuronide and pregnanediol glucuronide, respectively) and hCG levels were quantified in first morning urinary specimens using immunoassays to determine time of conception and confirm pregnancy maintenance. Linear mixed-effects models with regression splines were used to evaluate the magnitude and significance of changes in cortisol trajectories.

MAIN RESULTS AND THE ROLE OF CHANCE

Overall, maternal first morning urinary cortisol increased from 6 weeks prior to conception (geometric mean ± SD = 58.14 ± 36.00 ng/ml) to 6 weeks post-conception (89.29 ± 46.76 ng/ml). The magnitude of the increase between the pre- and post-conception periods varied significantly between women (likelihood ratio test statistic = 8.0017, P = 0.005). The peri-conceptional period is characterized by an increasing cortisol trajectory (+1.36% per day; P = 0.007) interrupted by a week-long decline immediately prior to conception (-4.02% per day; P = 0.0013). After conception cortisol increased again (+1.73% per day; P = 0.0008) for 4 weeks, fell in the fifth week (-6.60% per day; P = 0.0002) and increased again in post-conceptional week 6 (+8.86% per day; P = 0.002). Maternal urinary cortisol levels varied with sex of the gestating embryo. During gestational week 2, mothers carrying female embryos (N = 10) had higher mean cortisol levels than those carrying male embryos (N = 9) (t(17) = 2.28, P = 0.04).

LIMITATIONS, REASONS FOR CAUTION

Our results are based on a relatively small sample (n = 22) of women. However, our repeated-measures design with an average of 27 ± 8 (mean ± SD) data points per woman strengthens the precision of estimates resulting in high statistical power. Additionally, our study population's high degree of ethnic and cultural homogeneity reduces the effects of confounders compared with those found in industrialized populations. This higher level of homogeneity also increases our statistical power. However, since there may be small differences in absolute cortisol values among ethnic groups, the social and biological background of our sample may affect the generalizability of our results. General patterns of HPAA activity, however, are expected to be universal across women. Finally, as there is, to the best of our knowledge, no evidence to the contrary, we assumed that urinary cortisol levels reflect HPAA activity and that changes in gonadal steroids across the menstrual cycle do not affect the levels of free cortisol measured in urine.

WIDER IMPLICATIONS OF THE FINDINGS

To our knowledge, this is the first longitudinal profile of basal maternal HPAA activity across the peri-conceptional period. A basic understanding of the normative (basal as opposed to stress-induced) changes in HPAA activity across this period is needed to accurately assess women's stress at this juncture. Importantly, changes in HPAA activity are likely to play a critical role in ovulation, fertilization, implantation, placentation and embryonic programing. Thus, this novel information should aid in the development of interventions aimed at preventing or moderating undesired effects of maternal physiological stress during the peri-conceptional period on reproductive outcomes as well as embryonic development.

STUDY FUNDING/COMPETING INTERESTS

This research was funded by a CIHR IGH Open Operating grant (CIHR 106705) to P.A.N. and L.Z.; a Simon Fraser University (SFU) President's Start-up grant, a Community Trust Endowment Fund grant through SFU's Human Evolutionary Studies Program and a Michael Smith Foundation for Health Research Career Investigator Scholar Award to P.A.N.; an NSERC Discovery grant to L.Z.; a CIHR Post-Doctoral Fellowship to C.K.B. and an NSERC Undergraduate Student Research Award to H.M. and J.C.B. The funding agencies had no role in the design, analysis, interpretation or reporting of the findings. There are no competing interests.

TRIAL REGISTRATION NUMBER

Not applicable.

Genomic and proteomic features of mycobacteriophage SWU1 isolated from China soil

Mycobacteriophage SWU1 is a newly isolated phage from soil sample collected in Sichuan province, China using Mycobacterium smegmatis mc(2)155 as host. Plaque, phage morphology and one-step growth curve were characterized. The complete genomic sequence of phage SWU1 was determined by shotgun sequencing. The ends of SWU1 were determined. Structural proteins of SWU1 were analyzed by NanoLC-ESI-MS/MS. Seven ORFs were identified as structural protein encoded by SWU1 genome. The genetic basis underlying the SWU1 plaque was explored using comparative genomics. Prophages homologous to SWU1 were identified in two pathogens, Segniliparus rugosus ATCC BAA-974 and Mycobacterium rhodesiae JS60. Genus Segniliparus is a member of the order Corynebacteriales. To our knowledge, this is the first report of Mycobacterium prophages in different genera.

Homology difference analysis of invasive mealybug species Phenacoccus solenopsis Tinsley in Southern China with COI gene sequence variability

The mealybug species Phenacoccus solenopsis (P. solenopsis) has caused much agricultural damage since its recent invasion in China. However, the source of this invasion remains unclear. This study uses molecular methods to clarify the relationships among different population of P. solenopsis from China, USA, Pakistan, India, and Vietnam to determine the geographic origin of the introduction of this species into China. P. solenopsis samples were collected from 25 different locations in three provinces of Southern China. Samples from the USA, Pakistan, and Vietnam were also obtained. Parts of the mitochondrial genes for cytochrome oxidase I (COI) were sequenced for each sample. Homologous DNA sequences of the samples from the USA and India were downloaded from Gen Bank. Two haplotypes were found in China. The first was from most samples from the Guangdong, Guangxi, and Hainan populations in the China and Pakistan groups, and the second from a few samples from the Guangdong, Guangxi, Hainan populations in the China, Pakistan, India, and Vietnam groups. As shown in the maximum likelihood of trees constructed using the COI sequences, these samples belonged to two clades. Phylogenetic analysis suggested that most P. solenopsis mealybugs in Southern China are probably closely related to populations in Pakistan. The variation, relationship, expansion, and probable geographic origin of P. solenopsis mealybugs in Southern China are also discussed.

Reverse-dipper pattern of blood pressure may predict lacunar infarction in patients with essential hypertension

BACKGROUND AND PURPOSE

The fluctuation of circadian blood pressure (BP) is of great diversity in patients with essential hypertension and may provide significant prognostic value for stroke. However, it remains uncertain whether reverse-dipper pattern of BP influences the incidence of lacunar infarction in hypertensive patients.

METHODS

In the current study, 362 hypertensive patients (195 males, 167 females) were enrolled. BP patterns were evaluated with 24-h ambulatory BP monitoring (ABPM). Multinomial logistic regression was applied to analyse the possible relationships between lacunar infarction and various clinical risk factors such as ABPM.

RESULTS

A total of 93 patients (25.7%) had reverse-dipper BP pattern. Non-dipper pattern of BP was observed in 179 hypertensive patients (49.4%) and dipper pattern in 90 patients (24.9%). The percentage of lacunar infarction was the highest in the patients with reverse-dipper pattern compared with pure hypertension or atherothrombotic cerebral infarction (P < 0.05). After multinomial logistic regression analysis, reverse-dipper pattern of BP (odds ratio 2.492; 95% confidence interval 1.133-5.479; P < 0.05) and age (odds ratio 1.084; 95% confidence interval 1.047-1.123; P < 0.01) were found to be directly associated with lacunar infarction.

CONCLUSIONS

Reverse-dipper BP pattern may serve as an independent risk factor for lacunar infarction and more personalized BP management should be offered to the patients who have elevated nocturnal BP.

Comparison of the effects on glycaemic control and β-cell function in newly diagnosed type 2 diabetes patients of treatment with exenatide, insulin or pioglitazone: a multicentre randomized parallel-group trial (the CONFIDENCE study)

OBJECTIVE

Progressive β-cell dysfunction hinders the maintenance of glycaemic control in type 2 diabetes, but comparative data on β-cell-protective therapies are lacking in the early stage of type 2 diabetes. Here we evaluated the comparative glycaemic efficacy and impact on β-cell function of three antihyperglycaemic agents that have a β-cell-protective effect, exenatide, insulin and pioglitazone, in newly diagnosed patients with type 2 diabetes.

DESIGN AND METHODS

In this 48-week, multicentre, parallel-group study, 416 patients newly diagnosed with type 2 diabetes were randomly assigned 1 : 1 : 1 to receive exenatide, insulin or pioglitazone. The primary end-point was the change in glycosylated haemoglobin (HbA1c) from baseline. Secondary end-points included effects on weight, blood pressure, lipid profiles and β-cell function assessed by homeostasis model assessment, fasting proinsulin:insulin (PI/I), disposition index (DI) and acute insulin response (AIR).

RESULTS

At week 48, mean [95% confidence interval (CI)] HbA1c changes from baseline were -1.8% (-1.55% to -2.05%) with exenatide, -1.7% (-1.52% to -1.96%) with insulin and -1.5% (-1.23% to -1.71%) with pioglitazone. Treatment differences were -0.20% (95% CI -0.46% to 0.06%) for exenatide versus insulin (P = 0.185), and -0.37% (95% CI -0.63% to -0.12%) for exenatide versus pioglitazone (P = 0.002). Significant improvements from baseline in AIR, PI/I and DI were observed with all treatments, with the greatest improvements in DI, as well as weight, blood pressure and lipid profile, observed with exenatide.

CONCLUSIONS

All three agents showed efficacy regarding glycaemic control and metabolic benefits; however, exenatide showed the greatest efficacy. β-cell function improved in all treatment groups; hence, early initiation of β-cell-protective therapy may halt the decline in β-cell function in type 2 diabetes.

Serological surveillance for Penicillium marneffei infection in HIV-infected patients during 2004-2011 in Guangzhou, China

Prevalence of disseminated Penicillium marneffei infection is not known in human immunodeficiency virus (HIV)-infected patients. This retrospective study aimed to evaluate the prevalence of and risk factors for disseminated P. marneffei infection in HIV-infected patients during 2004-11 in Guangzhou, China. We tested 8131 archived HIV-infected patient serum samples for P. marneffei-specific mannoprotein (Mp1p) antigen using a highly sensitive and specific ELISA that we previously established. The CD4 count of 2686 cases was determined by flow cytometry. Logistic regression was used to assess predictors of Mp1p antigenaemia. The overall prevalence of disseminated penicilliosis as detected by positive serum Mp1p antigen was 9.36% (761/8131), in good concordance with Platelia™ Aspergillus immunoassay. During 2004-11, the prevalence increased to a peak of 12.58% (158/1256) in 2010 and decreased in 2011. Penicilliosis was strongly associated with progression from HIV to AIDS (OR 4.66, 95% CI 3.94-5.51, p <0.001) and humidity (OR 1.02, 95% CI 1.01-1.03, p 0.002). Disseminated penicilliosis occurred mainly during the rainy seasons (p <0.001). For 2686 cases with known CD4 count, logistic regression showed that CD4 count of <200 cells/μL was a risk factor for penicilliosis (OR 2.90, 95% CI 1.10-7.66, p 0.032), especially when it was <50 cells/μL (OR 24.26, 95% CI 10.63-55.36, p <0.001) during which 28.06% of patients developed disseminated penicilliosis. In conclusion, approximately 9.36% of the HIV-infected patients in our study developed disseminated penicilliosis. Rapid diagnosis may be achieved by performing serological surveillance for Mp1p antigenaemia as a routine procedure for all HIV-infected patients with CD4 count of <50 cells/μL.

Design of vibration compensation interferometer for Experimental Advanced Superconducting Tokamak

A vibration compensation interferometer (wavelength at 0.532 μm) has been designed and tested for Experimental Advanced Superconducting Tokamak (EAST). It is designed as a sub-system for EAST far-infrared (wavelength at 432.5 μm) poloarimeter/interferometer system. Two Acoustic Optical Modulators have been applied to produce the 1 MHz intermediate frequency. The path length drift of the system is lower than 2 wavelengths within 10 min test, showing the system stability. The system sensitivity has been tested by applying a periodic vibration source on one mirror in the system. The vibration is measured and the result matches the source period. The system is expected to be installed on EAST by the end of 2014.

Performance and data analysis aspects of the new DIII-D monostatic profile reflectometer system

A new frequency-modulated profile reflectometer system, featuring a monostatic antenna geometry (using one microwave antenna for both launch and receive), has been installed on the DIII-D tokamak, providing a first experimental test of this measurement approach for profile reflectometry. Significant features of the new system are briefly described in this paper, including the new monostatic arrangement, use of overmoded, broadband transmission waveguide, and dual-polarization combination/demultiplexing. Updated data processing and analysis, and in-service performance aspects of the new monostatic profile reflectometer system are also presented. By using a raytracing code (GENRAY) to determine the approximate trajectory of the probe beam, the electron density (ne) profile can be successfully reconstructed with L-mode plasmas vertically shifted by more than 10 cm off the vessel midplane. Specifically, it is demonstrated that the new system has a capability to measure ne profiles with plasma vertical offsets of up to ±17 cm. Examples are also presented of accurate, high time and spatial resolution density profile measurements made over a wide range of DIII-D conditions, e.g., the measured temporal evolution of the density profile across a L-H transition.

Optical layout and mechanical structure of polarimeter-interferometer system for Experimental Advanced Superconducting Tokamak

A Far-InfaRed (FIR) three-wave POlarimeter-INTerferometer (POINT) system for measurement current density profile and electron density profile is under development for the EAST tokamak. The FIR beams are transmitted from the laser room to the optical tower adjacent to EAST via ∼20 m overmoded dielectric waveguide and then divided into 5 horizontal chords. The optical arrangement was designed using ZEMAX, which provides information on the beam spot size and energy distribution throughout the optical system. ZEMAX calculations used to optimize the optical layout design are combined with the mechanical design from CATIA, providing a 3D visualization of the entire POINT system.

Faraday-effect polarimeter-interferometer system for current density measurement on EAST

A multichannel far-infrared laser-based POlarimeter-INTerferometer (POINT) system utilizing the three-wave technique is under development for current density and electron density profile measurements in the EAST tokamak. Novel molybdenum retro-reflectors are mounted in the inside wall for the double-pass optical arrangement. A Digital Phase Detector with 250 kHz bandwidth, which will provide real-time Faraday rotation angle and density phase shift output, have been developed for use on the POINT system. Initial calibration indicates the electron line-integrated density resolution is less than 5 × 10(16) m(-2) (∼2°), and the Faraday rotation angle rms phase noise is <0.1°.