Measuring the biological effect of presurgical metformin treatment in endometrial cancer

Background:

Preclinical studies in endometrial cancer (EC) show that metformin reduces cellular proliferation by PI3K-AKT-mTOR inhibition. We tested the hypothesis that short-term presurgical metformin reduces cellular proliferation in atypical endometrial hyperplasia (AEH) and endometrioid EC, and assessed the feasibility of using phosphorylated PI3K-AKT-mTOR proteins as tissue end points.

Methods:

Women with AEH or EC received metformin 850 mg twice a day or no drug in the presurgical window between diagnosis and hysterectomy. Before and after the window, tissue samples were obtained; serum markers of insulin resistance (e.g. homeostasis model of assessment of insulin resistance index) were determined; and anthropometrics measured (e.g. BMI). Cell proliferation (Ki-67) and PI3K-AKT-mTOR phosphostatus were assessed by immunohistochemistry and scored blinded to treatment.

Results:

Twenty-eight metformin-treated and 12 untreated patients, well matched for age and BMI, completed the study. Metformin treatment (median 20 days, range 7–34) was associated with a 17.2% reduction in tumour Ki-67 (95% CI −27.4, −7.0, P=0.002), in a dose-dependent manner. Tumour PI3K-AKT-mTOR protein phosphostatus varied but the effects were not significant after adjusting for changes in controls.

Conclusions:

Short-term metformin was associated with reduced Ki-67 expression in EC. Changes in tumour PI3K-AKT-mTOR protein phosphostatus were seen in both groups. Future studies should address the variability attributed to different sampling techniques including devascularisation of the uterus at hysterectomy.

Association of ACTN3 R577X but not ACE I/D gene variants with elite rugby union player status and playing position

We aimed to quantify the ACE I/D and ACTN3 R577X (rs1815739) genetic variants in elite rugby athletes (rugby union and league) and compare genotype frequencies to controls and between playing positions. The rugby athlete cohort consisted of 507 Caucasian men, including 431 rugby union athletes that for some analyses were divided into backs and forwards and into specific positional groups: front five, back row, half backs, centers, and back three. Controls were 710 Caucasian men and women. Real-time PCR of genomic DNA was used to determine genotypes using TaqMan probes and groups were compared using χ² and odds ratio (OR) statistics. Correction of P values for multiple comparisons was according to Benjamini-Hochberg. There was no difference in ACE I/D genotype between groups. ACTN3 XX genotype tended to be underrepresented in rugby union backs (15.7%) compared with forwards (24.8%, P = 0.06). Interestingly, the 69 back three players (wings and full backs) in rugby union included only six XX genotype individuals (8.7%), with the R allele more common in the back three (68.8%) than controls (58.0%; χ² = 6.672, P = 0.04; OR = 1.60) and forwards (47.5%; χ² = 11.768, P = 0.01; OR = 2.00). Association of ACTN3 R577X with playing position in elite rugby union athletes suggests inherited fatigue resistance is more prevalent in forwards, while inherited sprint ability is more prevalent in backs, especially wings and full backs. These results also demonstrate the advantage of focusing genetic studies on a large cohort within a single sport, especially when intrasport positional differences exist, instead of combining several sports with varied demands and athlete characteristics.

Changes from 1986 to 2006 in reasons for liking leisure-time physical activity among adolescents

Reasons for participating in physical activity (PA) may have changed in accordance with the general modernization of society. The aim is to examine changes in self-reported reasons for liking leisure-time physical activity (LTPA) and their association with self-reported LTPA over a 20-year period. Data were collected among nationally representative samples of 13-year-olds in Finland, Norway, and Wales in 1986 and 2006 (N = 9252) as part of the WHO cross-national Health Behaviour in School-aged Children (HBSC) study. Univariate ANOVAs to establish differences according to gender, year, and country were conducted. In all countries, 13-year-olds in 2006 tended to report higher importance in terms of achievement and social reasons than their counterparts in 1986, while changes in health reasons were minor. These reasons were associated with LTPA in a similar way at both time points. Health reasons for liking LTPA were considered most important, and were the strongest predictor of LTPA. The findings seem robust as they were consistent across countries and genders. Health education constitutes the most viable strategy for promoting adolescents' motivation for PA, and interventions and educational efforts could be improved by an increased focus on LTPA and sport as a social activity.

Development of a human papillomavirus competitive luminex immunoassay for 9 HPV types

In the clinical trials of the quadrivalent human papillomavirus (qHPV) vaccine, antibodies were measured by a competitive Luminex immunoassay (HPV-4 cLIA). A nine-valent HPV (9vHPV) vaccine targeting the types in the qHPV vaccine (HPV6/11/16/18), as well as 5 of the next most frequent HPV types found in cervical cancers worldwide (HPV31/33/45/52/58) is under development. To support the 9vHPV vaccine program, a nine-multiplexed cLIA (HPV-9 cLIA) was developed. Antibody titers were determined in a competitive format, where type-specific phycoerythrin (PE)-labeled, neutralizing mAbs (mAbs-PE) compete with an individual's serum antibodies for binding to conformationally sensitive, neutralizing epitopes on the VLPs. Neutralizing antibody levels were quantitated against a reference standard - a pool of sera from 6 Rhesus macaques that were immunized with the 9vHPV vaccine. Specificity of the mAbs was assessed by measuring their individual binding capacities to the type-specific and non-type-specific VLPs at alternative concentrations of the mAbs. Antibody assignments to the HPV-9 cLIA reference standard for HPV6/11/16/18 were determined to provide for a measure of consistency in serostatus assignment between the HPV-4 and HPV-9 cLIAs. Antibody assignments to the HPV-9 reference standard for HPV31/33/45/52/58 were obtained by calibration to HPV11 using a direct binding IgG assay. For each HPV VLP type, the cross-reactivity of the mAb-PEs in the HPV-9 cLIA was <1% (i.e., the mAb-PEs result in <1% non-specific binding). The antibody concentrations assigned to the HPV-9 cLIA reference standard for types 6/11/16/18/31/33/45/52/58 were 3,817, 2,889, 23,061, 5,271, 3,942, 2,672, 1,489, 1274, and 2263 mMU/mL, respectively.

Food for thought: pilot randomized controlled trial of lay health trainers supporting dietary change to reduce cardiovascular disease in deprived communities

BACKGROUND

Cardiovascular disease (CVD) accounts for 30% of UK deaths. It is associated with modifiable lifestyle factors, including insufficient consumption of fruit and vegetables (F&V). Lay health trainers (LHTs) offer practical support to help people develop healthier behaviour and lifestyles. Our two-group pilot randomized controlled trial (RCT) investigated the effectiveness of LHTs at promoting a heart-healthy lifestyle among adults with at least one risk factor for CVD to inform a full-scale RCT.

METHODS

Eligible adults (aged 21-78 years), recruited from five practices serving deprived populations, were randomized to health information leaflets plus LHTs' support for 3 months (n = 76) versus health information leaflets alone (n = 38).

RESULTS

We recruited 114 participants, with 60% completing 6 month follow-up. Both groups increased their self-reported F&V consumption and we found no evidence for LHTs' support having significant added impact. Most participants were relatively less deprived, as were the LHTs we were able to recruit and train.

CONCLUSIONS

Our pilot demonstrated that an LHT's RCT whilst feasible faces considerable challenges. However, to justify growing investment in LHTs, any behaviour changes and sustained impact on those at greatest need should be demonstrated in an independently evaluated, robust, fully powered RCT.