Cellular and clinical impact of protein phosphatase enzyme epigenetic silencing in multiple cancer tissues

BACKGROUND

Protein Phosphatase Enzymes (PPE) and protein kinases simultaneously control phosphorylation mechanisms that tightly regulate intracellular signalling pathways and stimulate cellular responses. In human malignancies, PPE and protein kinases are frequently mutated resulting in uncontrolled kinase activity and PPE suppression, leading to cell proliferation, migration and resistance to anti-cancer therapies. Cancer associated DNA hypermethylation at PPE promoters gives rise to transcriptional silencing (epimutations) and is a hallmark of cancer. Despite recent advances in sequencing technologies, data availability and computational capabilities, only a fraction of PPE have been reported as transcriptionally inactive as a consequence of epimutations.

METHODS

In this study, we examined promoter-associated DNA methylation profiles in Protein Phosphatase Enzymes and their Interacting Proteins (PPEIP) in a cohort of 705 cancer patients in five tissues (Large intestine, Oesophagus, Lung, Pancreas and Stomach) in three cell models (primary tumours, cancer cell lines and 3D embedded cancer cell cultures). As a subset of PPEIP are known tumour suppressor genes, we analysed the impact of PPEIP promoter hypermethylation marks on gene expression, cellular networks and in a clinical setting.

RESULTS

Here, we report epimutations in PPEIP are a frequent occurrence in the cancer genome and manifest independent of transcriptional activity. We observed that different tumours have varying susceptibility to epimutations and identify specific cellular signalling networks that are primarily affected by epimutations. Additionally, RNA-seq analysis showed the negative impact of epimutations on most (not all) Protein Tyrosine Phosphatase transcription. Finally, we detected novel clinical biomarkers that inform on patient mortality and anti-cancer treatment sensitivity.

CONCLUSIONS

We propose that DNA hypermethylation marks at PPEIP frequently contribute to the pathogenesis of malignancies and within the precision medicine space, hold promise as biomarkers to inform on clinical features such as patient survival and therapeutic response.

Community engagement in public health emergency preparedness

Background

Communities that could be affected by infectious disease outbreaks are increasingly recognised as resources that may be effectively utilized by the authorities during public health emergencies.

Methods

This case study project, aiming to identify synergies between communities and authorities, was based on qualitative sources of evidence, including document and media review, stakeholder mapping, interviews and FGDs (N = 137). Four countries were selected for inclusion: Spain and the Netherlands on the basis of emerging tick-born disease incidents; Iceland and Ireland on the basis of acute gastroenteritis outbreaks.

Results

In the Netherlands and Spain strong synergies were identified in tick surveillance activities, and the value of pre-existing networks of interest groups for preparedness and response activities was recognised. The Icelandic norovirus event was unexpected and fast-moving, while VTEC in Ireland is a familiar and slower-burning challenge. As a relatively common disease in Ireland, VTEC-protocols are closely followed, while a generic all-hazards approach was taken in Iceland. There was considerable community support in the responses in both countries., and in Iceland community representatives also actively participated in producing institutional post-event evaluations.

Conclusions

An over-riding principle emerging from this study is that an informed, at-risk community understands the challenges to adopting effective preventive practices for themselves better than anyone. Additional good practices included the utilisation of pre-existing stakeholder networks for information dissemination; and of monitoring community perceptions of any public health incident, including through social media, in order to identify and manage misperceptions. Efforts to build on the community engagement activities that are already in place in the four countries could contribute to better preparedness planning and more efficient and timely responses in future outbreaks.

Key messages

Recognise the community as a real partner in outbreak preparedness, response, and recovery. Optimise communications with communities who may be affected by outbreaks.

Evaluating the impact of an insulin pump discontinuation action plan on patient or caregiver confidence and anxiety

Aims

Insulin pump failure and adverse events are common and therefore anticipatory education is recommended. Research in other chronic diseases shows written action plans improve confidence and adherence during an acute deterioration. However, no similar data exists for patients with type one diabetes mellitus provided with anticipatory education via an insulin pump action plan. This study evaluates whether an insulin pump action plan improves patient and caregiver confidence in managing a potential pump failure without a subsequent increase in anxiety.

Methods

Adults with type one diabetes mellitus and caregivers of children with type 1 diabetes on continuous subcutaneous insulin infusions across four New Zealand diabetes services participated. Participants completed a questionnaire examining pump-related adverse events and self-reported confidence and anxiety in managing pump failure. An insulin pump action plan and focused education by their diabetes team was provided, with a follow-up questionnaire at least 3 months later.

Results

174/270 pump patients participated initially, with a follow-up response rate of 84.5% (147/174). Despite prior provision, many could not recall having an insulin pump action plan at study commencement (101/174, 58%), and of these 92% stated they would have liked one. Patients had good levels of confidence in the reliability of their pump and infusion sets/sites (Likert scores of 4.4/5 and 3.95/5) which was not undermined by the insulin pump action plan. Confidence in managing a potential pump failure showed a small but significant increase (3.66/5 to 3.95/5, p = 0.004) present in both adults and parents, with anxiety also showing a small increase (2.16/5 to 2.38/5, p = 0.012).

Conclusion

Patient recall of prior insulin pump action plan education is poor, with the vast majority of patients interested in further written anticipatory education regarding potential pump failure. The provision of an insulin pump action plan increases self-reported confidence in managing unexpected pump failure with a small associated increase in anxiety.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Weight-based carbohydrate treatment of hypoglycaemia in people with Type 1 diabetes using insulin pump therapy: a randomized crossover clinical trial

AIM

To test whether weight-based treatment is more effective than usual care in people with Type 1 diabetes receiving continuous subcutaneous insulin infusion therapy with regard to both hypoglycaemia and avoiding excessive rebound hyperglycaemia.

METHODS

Children and adults on continuous subcutaneous insulin infusion were enrolled into a study with a crossover design. Each episode of hypoglycaemia (defined as capillary glucose <4.0 mmol/l) was randomly assigned one of two treatment protocols using glucose tablets: either 0.3 g/kg body weight or usual treatment with 15 g (adults) or 10 g (children) for capillary glucose levels 3-3.9 mmol/l or twice these doses for capillary glucose levels <3 mmol/l. All participants received each treatment in random order for up to 10 hypoglycaemic episodes. Glucose levels were re-tested 10 min after treatment, with a repeat dose if still <4 mmol/l.

RESULTS

Of the 37 participants enrolled, 35 (aged 6-68 years) completed the study. Twenty-four participants completed all treatment episodes, while 10 participants had <10 hypoglycaemic episodes and two withdrew without data. The mean glucose difference between weight-based and usual treatment after 10 min was 0.33 mmol/l (95% CI 0.005 to 0.66; P=0.047) in adults and 0.45 (95% CI 0.18 to 0.72; P=0.001) in children. The odds ratios for resolution of hypoglycaemia at 10 min with a single treatment using weight-based compared with usual treatment were 3.12 (95% CI 1.38 to 7.02; P=0.0070) in adults and 2.61 (95% CI 1.19 to 5.74; P=0.017) in children.

CONCLUSIONS

Weight-based treatment using 0.3 g/kg glucose was more effective for symptomatic hypoglycaemia in children and adults with Type 1 diabetes who were using continuous subcutaneous insulin infusion than treatment based on current international recommendations.

Insulin pump-associated adverse events are common, but not associated with glycemic control, socio-economic status, or pump/infusion set type

AIMS

While there have been many outcome-focussed studies examining insulin pump therapy, only a few have looked at potential adverse events (AEs), with none examining the relationship between AEs and pump/infusion set type, ethnicity or socio-economic status. In addition, current data on the incidence and characteristics of pump-associated AEs are confined to one paediatric centre. We aimed to describe the incidence, characteristics and potential predictors of insulin pump-associated AEs in New Zealand adults and children with T1DM.

METHODS

We approached adults and families of children with T1DM on insulin pumps in four main New Zealand centres. Participants completed a questionnaire examining pump-related issues they had experienced in the preceding 12 months.

RESULTS

Response rate was 64 % with 174 of 270 eligible people participating in the study. 84 % of subjects reported one or more AEs, with an overall AE incidence of 3.42 per person/year (95 % CI 3.14, 3.73). An event serious enough to require a hospital presentation occurred in 9.8 %, all but one reporting high ketones or diabetic ketoacidosis (DKA). Set/site problems were the AE most commonly reported (by 53 % of respondents), followed by cutaneous complications (43 %) and pump malfunction (38 %). Few predictors of AEs (of any type) were found; however, a negative binomial regression model found that a longer duration of pumping (p = 0.018) and age <18 years (p = 0.043) were both associated with fewer AEs (all types combined).

CONCLUSIONS

Insulin pump-associated AEs are very common. However, few variables are predictive of them with no relationships seen with glycaemic control, socio-economic status, pump manufacturer or infusion set type. Based on these findings, AEs should be anticipated in both adults and children, with anticipatory patient education and training recommended for their successful and safe use.

Clinical review: insulin pump-associated adverse events in adults and children

AIMS

Insulin pumps are a vital and rapidly developing tool in the treatment of type 1 diabetes mellitus in both adults and children. Many studies have highlighted outcomes and assessed their potential advantages, but much of the data on adverse outcomes are limited and often based on outdated technology. We aimed to review and summarize the available literature on insulin pump-associated adverse events in adults and children.

METHODS

A literature search was undertaken using PubMed, EMBASE, and the Cochrane library. Articles were then screened by title, followed by abstract, and full text as needed. A by-hand search of reference lists in identified papers was also utilised. All searches were limited to English language material, but no time limits were used.

RESULTS

Current and past literature regarding insulin pump-associated adverse events is discussed, including potential metabolic and non-metabolic adverse events, in particular: pump malfunction; infusion set/site issues; and cutaneous problems. We show that even with modern technology, adverse events are common, occurring in over 40 % of users per year, with a minority, particularly in children, requiring hospital management. Hyperglycaemia and ketosis are now the most common consequences of adverse events and are usually associated with infusion set failure. This differs from older technology where infected infusion sites predominated.

CONCLUSIONS

This timely review covers all potential insulin pump-associated adverse events, including their incidence, features, impacts, and contributory factors such as the pump user. The importance of ongoing anticipatory education and support for patients and families using this intensive insulin technology is highlighted, which if done well should improve the overall experience of pump therapy for users, and hopefully reduce the incidence and impact of severe adverse events.

Weight-based hypoglycaemia treatment protocol for adults with Type 1 diabetes: a randomized crossover clinical trial

AIM

To determine whether a weight-based hypoglycaemia treatment using 0.3 g/kg (or 0.2 g/kg) glucose effectively treats adults with Type 1 diabetes mellitus compared with an internationally recommended 15-g treatment.

METHODS

Patients with frequent hypoglycaemia were recruited from hospital-based diabetes clinics. The treatment for each hypoglycaemic episode, defined as capillary glucose <4.0 mmol/l, was randomly assigned to one of three protocols: 0.2 g/kg, 0.3 g/kg, or 15 g, using Dextro(TM) glucose tablets (Dextro Energy, Krefeld, Germany). Each participant received each treatment in random order for up to 15 hypoglycaemic episodes. Capillary glucose was re-tested 10 min after treatment, with a repeat dose if still < 4 mmol/l.

RESULTS

The study recruited 34 participants aged 22-71 years, whose mean (sd) BMI was 25.2 (3.1) kg/m(2) and HbA1c 63 (10.4) mmol/mol [7.9 (0.9)%]. Two people withdrew because they did not like the taste of the Dextro tablets and one was excluded because they used their own glucose preparation. Unadjusted for clustering within participants, the mean (sd) capillary glucose after 10 min was 4.67 (1.25) mmol/l for 0.3 g/kg (141 episodes), 4.29 (0.94) mmol/l for 0.2 g/kg (132 episodes), and 4.37(0.99) mmol/l for 15 g (136 episodes). Capillary glucose, adjusted for clusters and baseline, was higher after 10 min for 0.3 g/kg glucose compared with 15 g glucose; a difference of 0.26 (95% CI 0.04-0.48) mmol/l (P = 0.02), but not for 0.2 g/kg; -0.07 (95% CI -0.29-0.16) mmol/l (P = 0.56). Capillary glucose for only three hypoglycaemic episodes rose above 8 mmol/l.

CONCLUSIONS

A weight-based protocol of 0.3 g/kg glucose appears more effective for treating symptomatic hypoglycaemia in adults with Type 1 diabetes than either the most common current recommendation of 15 g glucose or a 0.2 g/kg glucose dose.

Urine amino and organic acids analysis in developmental delay or intellectual disability

OBJECTIVES

To determine the proportion of urine amino and organic acids screening tests (UMS) undertaken for patients referred with developmental delay or intellectual disability (DD/ID), and within the group with DD/ID, to determine the diagnostic yield, the proportion of diagnoses with a therapy and the associated recurrence risks.

METHODS

A retrospective review of request forms and results of UMS, in individuals older than 28 days, referred to the Women's and Children's Hospital, North Adelaide, between 1 January 1992 and 31 December 1998 was carried out. Urine was analysed by ion exchange chromatography (amino acids), gas chromatography/mass spectrometry (organic acids), colorimetric assay (orotic acid) and stable isotope-dilution mass spectrometry (trimethylamine).

RESULTS

A total of 3316 samples were received, 1447 being from patients with DD/ID. A diagnosis was determined for 1.8% of all referrals. For patients with DD/ID, the diagnostic yield was 1.1%, with a similar yield for isolated DD/ID and DD/ID with other features (9/828 vs 7/619; chi2 = 0.006; P = 0.93). Specific therapies were available for 69% of diagnoses associated with DD/ID and 87.5% had known Mendelian or mitochondrial inheritance.

CONCLUSION

Urine metabolic screening is an important part of the evaluation of children with DD/ID as it can enable families to make reproductive decisions and children to receive appropriate therapy early.

Variable presentation of X-linked adrenal hypoplasia congenita

We present a family with X-linked adrenal hypoplasia congenita (AHC) due to a truncation mutation in the DAX1 gene. The three patient reports demonstrate variable clinical and biochemical features at presentation. They presented with adrenal crises at 3 years, 4 weeks, and 3 weeks. Mineralocorticoid deficiency preceded glucocorticoid deficiency in patient 3 and an early ultrasound indicated normal sized adrenal tissue. Genetic analysis showed that potential female carriers were unaffected.

Reduced total plasma homocyst(e)ine in children and adolescents with type 1 diabetes

OBJECTIVES

The objective was to investigate total plasma homocyst(e)ine (tHcy), methylenetetrahydrofolate reductase (MTHFR) genotype, and the contribution of diet to homocysteine values in children and adolescents with type 1 diabetes and a control group.

STUDY DESIGN

A total of 78 children with type 1 diabetes and 59 members of an age- and sex-matched control group were recruited. Fasting samples were collected for tHcy, MTHFR genotype, serum vitamin B(12), serum folate, red cell folate, and plasma creatinine. Food frequency questionnaires targeted intake of folate, vitamin B(6), and vitamin B(12).

RESULTS

Fasting tHcy was reduced in patients compared with the control group (4.7 vs 5.9 micromol/L, P <.001). Serum folate (P =.002), red cell folate(P <.001), and serum vitamin B(12) (P =.005) were higher, and plasma creatinine was lower. A significant difference in tHcy values between patients and the control group persisted after correction was done for these factors (r = 0.1, P =.02). No difference was seen in the frequency of MTHFR polymorphisms. tHcy was not elevated in those patients with the 677TT or 677T/1298C genotypes, although red cell folate was significantly higher in members of the case (P =.01) and control groups (P =.05) with a 677 TT genotype. Dietary intake of folate correlated with serum folate (r = 0.4,P =.005).

CONCLUSION

tHcy values are lower in children and adolescents with type 1 diabetes. Higher serum levels of folic acid and vitamin B(12), reflecting differences in dietary intake between children with diabetes and members of a control group, partially account for this difference.