PIGA mutations and glycosylphosphatidylinositol anchor dysregulation in polyposis-associated duodenal tumorigenesis

The pathogenesis of duodenal tumours in the inherited tumour syndromes Familial Adenomatous Polyposis (FAP) and MUTYH-associated Polyposis (MAP) is poorly understood. This study aimed to identify genes that are significantly mutated in these tumours and to explore the effects of these mutations. Whole exome and whole transcriptome sequencing identified recurrent somatic coding variants of PIGA in 19/70 (27%) FAP and MAP duodenal adenomas, and further confirmed the established driver roles for APC and KRAS. PIGA catalyses the first step in glycosylphosphatidylinositol (GPI) anchor biosynthesis. Flow cytometry of PIGA-mutant adenoma-derived and CRISPR-edited duodenal organoids confirmed loss of GPI anchors in duodenal epithelial cells and transcriptional profiling of duodenal adenomas revealed transcriptional signatures associated with loss of PIGA. Implications: PIGA somatic mutation in duodenal tumours from patients with FAP and MAP and loss of membrane GPI-anchors may present new opportunities for understanding and intervention in duodenal tumorigenesis.

The PIG-A gene mutation assay in human biomonitoring and disease

The blood cell phosphatidylinositol glycan class A (PIG-A) gene mutation assay has been extensively researched in rodents for in vivo mutagenicity testing and is now being investigated in humans. The PIG-A gene is involved in glycosyl phosphatidylinositol (GPI)-anchor biosynthesis. A single mutation in this X-linked gene can lead to loss of membrane-bound GPI anchors, which can be enumerated via corresponding GPI-anchored proteins (e.g., CD55) using flow cytometry. The studies published to date by different research groups demonstrate a remarkable consistency in PIG-A mutant frequencies. Moreover, with the low background level of mutant erythrocytes in healthy subjects (2.9-5.56 × 10-6 mutants), induction of mutation post genotoxic exposure can be detected. Cigarette smoking, radiotherapy, and occupational exposures, including lead, have been shown to increase mutant levels. Future applications of this test include identifying new harmful agents and establishing new exposure limits. This mutational monitoring approach may also identify individuals at higher risk of cancer development. In addition, identifying protective agents that could mitigate these effects may reduce baseline somatic mutation levels and such behaviors can be encouraged. Further technological progress is required including establishing underlying mechanisms of GPI anchor loss, protocol standardization, and the development of cryopreservation methods to improve GPI-anchor stability over time. If successful, this assay has the potential be widely employed, for example, in rural and low-income countries. Here, we review the current literature on PIG-A mutation in humans and discuss the potential role of this assay in human biomonitoring and disease detection.

Classifying the unclassifiable-a Delphi study to reach consensus on the fibrotic nature of diseases

BACKGROUND

Traditionally, clinical research has focused on individual fibrotic diseases or fibrosis in a particular organ. However, it is possible for people to have multiple fibrotic diseases. While multi-organ fibrosis may suggest shared pathogenic mechanisms, yet there is no consensus on what constitutes a fibrotic disease and therefore fibrotic multimorbidity.

AIM

A Delphi study was performed to reach consensus on which diseases may be described as fibrotic.

METHODS

Participants were asked to rate a list of diseases, sub-grouped according to eight body regions, as 'fibrotic manifestation always present', 'can develop fibrotic manifestations', 'associated with fibrotic manifestations' or 'not fibrotic nor associated'. Classifications of 'fibrotic manifestation always present' and 'can develop fibrotic manifestations' were merged and termed 'fibrotic'. Clinical consensus was defined according to the interquartile range, having met a minimum number of responses. Clinical agreement was used for classification where diseases did not meet the minimum number of responses (required for consensus measure), were only classified if there was 100% consensus on disease classification.

RESULTS

After consulting experts, searching the literature and coding dictionaries, a total of 323 non-overlapping diseases which might be considered fibrotic were identified; 92 clinical specialists responded to the first round of the survey. Over three survey rounds, 240 diseases were categorized as fibrotic via clinical consensus and 25 additional diseases through clinical agreement.

CONCLUSION

Using a robust methodology, an extensive list of diseases was classified. The findings lay the foundations for studies estimating the burden of fibrotic multimorbidity, as well as investigating shared mechanisms and therapies.

Measuring blood cell DNA damage using the PIG-A mutation and CBMN assay in pancreatic cancer patients: a pilot study

Pancreatic cancer still has one of the worst prognoses of all solid malignancies, despite developments in cancer knowledge and care. Research into pancreatic cancer has not fully translated into clinical improvements and as a result, fewer than 1% of patients survive 10 years post-diagnosis. This bleak outlook for patients could be improved by earlier diagnosis. The human erythrocyte phosphatidylinositol glycan class A (PIG-A) assay monitors the mutation status of the X-linked PIG-A gene by measuring glycosyl phosphatidylinositol (GPI)-anchored proteins on the extracellular surface. We have previously identified an elevated PIG-A mutant frequency in oesophageal adenocarcinoma patients and here investigate whether this could be seen in a pancreatic cancer cohort, given the urgent need for novel pancreatic cancer biomarkers. In our pilot study, an elevated PIG-A mutant frequency (5.775 × 10-6 (95% CI 4.777-10) mutants per million) was seen in pancreatic cancer patients (n = 30) when compared to the non-cancer control group (n = 14) who had an erythrocyte mutant frequency of 4.211 × 10-6 (95% CI 1.39-5.16) mutants per million (p = 0.0052). A cut-off value of 4.7 mutants per million provided an AUROC of 0.7595 with a sensitivity of 70% and specificity of 78.57%. A secondary measure of DNA damage in an alternative blood cell population also showed an increase in peripheral lymphocytes using the cytokinesis-block micronucleus assay (p = 0.0164) (AUROC = 0.77, sensitivity = 72.22%, specificity = 72.73%). The micronucleus frequency and PIG-A status show some potential as blood-based biomarkers of pancreatic cancer, but further investigations of these DNA damage tests are required to assess their utility in pancreatic cancer diagnosis.

Lower polyunsaturated fatty acid levels and FADS2 expression in adult compared to neonatal keratinocytes are associated with FADS2 promotor hypermethylation

Keratinocytes produce lipids that are critical for the skin barrier, however, little is known about the impact of age on fatty acid (FA) biosynthesis in these cells. We have examined the relationship between keratinocyte FA composition, lipid biosynthetic gene expression, gene promoter methylation and age. Expression of elongase (ELOVL6 and 7) and desaturase (FADS1 and 2) genes was lower in adult versus neonatal keratinocytes, and was associated with lower concentrations of n-7, n-9 and n-10 polyunsaturated FA in adult cells. Consistent with these findings, transient FADS2 knockdown in neonatal keratinocytes mimicked the adult keratinocyte FA profile in neonatal cells. Interrogation of methylation levels across the FADS2 locus (53 genomic sites) revealed differential methylation of 15 sites in neonatal versus adult keratinocytes, of which three hypermethylated sites in adult keratinocytes overlapped with a SMARCA4 protein binding site in the FADS2 promoter.

The Impact of a Centralised Pancreatic Cancer Service: a Case Study of Wales, UK

INTRODUCTION

The centralisation of pancreatic cancer (PC) services still varies worldwide. This study aimed to assess the impact that a centralisation has had on patients in South Wales, UK.

METHODS

A retrospective cohort analysis of patients in South Wales, UK, with PC prior to (2004-2009), and after (2010-2014) the formation of a specialist centre. Patients were identified using record linkage of electronic health records.

RESULTS

The overall survival (OS) of all 3413 patients with PC increased from a median (IQR) 10 weeks (3-31) to 11 weeks (4-35), p = 0.038, after centralisation. The OS of patients undergoing surgical resection or chemotherapy alone did not improve (93 weeks (39-203) vs. 90 weeks (50-95), p = 0.764 and 33 weeks (20-57) vs. 33 weeks (19-58), p = 0.793). Surgical resection and chemotherapy rates increased (6.1% vs. 9.2%, p < 0.001 and 19.7% vs. 27.0%, p < 0.001). The 30-day mortality rate trended downwards (7.2% vs. 3.6%, p = 0.186). The percentage of patients who received no treatment reduced (75.2% vs. 69.6%, p < 0.001).

CONCLUSION

The centralisation of PC services in South Wales is associated with a small increase in OS and a larger increase in PC treatment utilisation. It is concerning that many patients still fail to receive any treatments.

The Role of Meteorological Variables and Aerosols in the Transmission of COVID-19 During Harmattan Season

The role of atmospheric parameters and aerosols in the transmission of COVID-19 within tropical Africa, especially during the harmattan season, has been under-investigated in published papers. The harmattan season within the West African region is associated with significant dust incursion from the Bodele depression and biomass burning. In this study, the correlation between atmospheric parameters (temperature and humidity) and aerosols with COVID-19 cases and fatalities within seven locations in tropical Nigeria during the harmattan period was investigated. COVID-19 infection cases were found to be significantly positively correlated with atmospheric parameters (temperature and humidity) in the southern part of the country while the number of fatalities showed weaker significant correlation with particulate matters only in three locations. The significant correlation values were found to be between 0.22 and 0.48 for particulate matter and -0.19 to -0.32 for atmospheric parameters. Although, temperature and humidity showed negative correlations in some locations, the impact is smaller compared to particulate matter. In December, COVID-19 cases in all locations showed strong correlation with particulate matter except in Kano State. It is suggested that a reduction in atmospheric particulate matter can be used as a control measure for the spread of COVID-19.

The Role of National Specialist Societies in Influencing Transformational Change in Low-Middle Income Countries - Reflections on the Model of Implementation for a National Endoscopy Training Programme in Bangladesh

The British Society of Gastroenterology (BSG) and the Bangladesh Gastroenterology Society (BGS) have collaborated on an endoscopy training programme, which has grown up over the past decade from a small scheme borne out of the ideas of consultant gastroenterologists in Swansea, South Wales (United Kingdom) to improve gastroenterology services in Bangladesh to become a formalised training programme with broad reach. In this article, we document the socioeconomic and historical problems that beset Bangladesh, the current training needs of doctors and how the BSG-BGS collaboration has made inroads into changing outcomes both for gastroenterologists in Bangladesh, but also for the populations they serve.

Can biomarkers of extracellular matrix remodelling and wound healing be used to identify high risk patients infected with SARS-CoV-2?: lessons learned from pulmonary fibrosis

Pulmonary fibrosis has been identified as a main factor leading to pulmonary dysfunction and poor quality of life in post-recovery Severe Acute Respiratory Syndrome (SARS) survivor’s consequent to SARS-Cov-2 infection. Thus there is an urgent medical need for identification of readily available biomarkers that in patients with SARS-Cov-2 infection are able to; (1) identify patients in most need of medical care prior to admittance to an intensive care unit (ICU), and; (2) identify patients post-infection at risk of developing persistent fibrosis of lungs with subsequent impaired quality of life and increased morbidity and mortality. An intense amount of research have focused on wound healing and Extracellular Matrix (ECM) remodelling of the lungs related to lung function decline in pulmonary fibrosis (PF). A range of non-invasive serological biomarkers, reflecting tissue remodelling, and fibrosis have been shown to predict risk of acute exacerbations, lung function decline and mortality in PF and other interstitial lung diseases (Sand et al. in Respir Res 19:82, 2018). We suggest that lessons learned from such PF studies of the pathological processes leading to lung function decline could be used to better identify patients infected with SARS-Co-V2 at most risk of acute deterioration or persistent fibrotic damage of the lung and could consequently be used to guide treatment decisions.

Dietary and lifestyle factors effect erythrocyte PIG-A mutant frequency in humans

It is well understood that poor diet and lifestyle choices can increase the risk of cancer. It is also well documented that cancer is a disease of DNA mutations, with mutations in key genes driving carcinogenesis. Measuring these mutations in a minimally invasive way may be informative as to which exposures are harmful and thus allow us to introduce primary preventative measures, in a bid to reduce cancer incidences. Here, we have measured mutations in the phosphatidylinositol glycan class A (PIG-A) gene in erythrocytes from healthy volunteers (n = 156) and from non-cancer patients attending the local endoscopy department (n = 144). The X-linked PIG-A gene encodes an enzyme involved in glycosylphosphatidylinositol (GPI) anchor synthesis. A silencing mutation in which leads to the absence of GPI anchors on the extracellular surface which can be rapidly assessed using flow cytometry. The background level of PIG-A mutant erythrocytes was 2.95 (95% CI: 2.59-3.67) mutant cells (10-6). Older age increased mutant cell frequency (P < 0.001). There was no difference in mutant cell levels between males and females (P = 0.463) or smokers and non-smokers (P = 0.186). In the endoscopy group, aspirin users had lower mutant frequencies (P = 0.001). Further information on diet and exercise was available for the endoscopy patient group alone, where those with a higher health promotion index score had lower mutant frequencies (P = 0.011). Higher dietary intake of vegetables reduced mutant cell levels (P = 0.022). Participants who exercised for at least 1 h a week appeared to have reduced mutant frequencies than those who did not exercise, although this was not statistically significant (P = 0.099). This low background level of mutant erythrocytes in a population makes this assay an attractive tool to monitor exposures such as those associated with lifestyles and diet, as demonstrated here.

Effect of breed as a risk factor for humeral condylar fracture in skeletally immature dogs

OBJECTIVES

To investigate the effect of breed as a risk factor associated with humeral condylar fracture in skeletally immature dogs in the UK.

MATERIALS AND METHODS

Retrospective study of dogs under 12 months of age that were presented with humeral condylar fracture to three specialist referral centres between 2015 and 2018. Data retrieved from medical records included breed, age, gender, neuter status, affected limb, fracture configuration and aetiology of the fracture. Breed population percentages were compared with those recorded by the UK Kennel Club.

RESULTS

Of the 115 dogs with 118 fractures, French bulldogs (41%) and English springer spaniels (15%) were overrepresented: humeral condylar fractures were more commonly diagnosed in French bulldogs (odds ratio = 5.86) and English springer spaniels (odds ratio = 5.66) compared with mixed-breed dogs. Lateral condylar fractures occurred in 70% of cases, with medial condylar fractures and Y/T fractures accounting for 9% and 21%, respectively. Median age at the time of fracture was 4 months (range 2 to 10 months).

CLINICAL SIGNIFICANCE

French bulldogs and English springer spaniels were identified as being at potentially increased risk of humeral condylar fracture in skeletally immature dogs.

Diaphragmotomy to aid exposure during hepatobiliary surgery: a multi-centre retrospective review of 31 dogs

OBJECTIVES

To report surgical technique, intra- and post-operative complications, and short- and long-term outcome following canine hepatobiliary surgery in which exposure of intra-abdominal hepatobiliary lesions was aided by diaphragmotomy.

MATERIALS AND METHODS

Clinical records from four multi-disciplinary UK-based small animal referral hospitals were retrospectively reviewed for dogs in which diaphragmotomy was performed between January 2014 and May 2019. Signalment, diagnosis, surgery performed, diaphragmotomy technique, management of diaphragmotomy and pneumothorax, intra- and post-operative complications, short-term outcome and long-term outcome were recorded.

RESULTS

Thirty-one cases were identified. The most common hepatobiliary surgeries performed alongside diaphragmotomy were single hepatic lobectomy (14/31) and cholecystectomy (11/31). The most common diagnoses were hepatocellular carcinoma (10/31), gall bladder mucocoele (7/31) and hepatic nodular hyperplasia (4/31). Peri-operative mortality rate was 9.7% (3/31 cases) though none of these deaths were considered attributable to diaphragmotomy. Post-operative complications were encountered in 67.9% (19/28) cases that survived the peri-operative period, of which 25.0% (7/28) suffered complications that were considered attributable or likely attributable to diaphragmotomy. These seven complications resolved following non-surgical intervention. Follow-up was available for 26 of 28 patients that survived to discharge at a median of 4-months (range 10 days to 24 months) following surgery and revealed no evidence of complications related to diaphragmotomy.

CLINICAL SIGNIFICANCE

Diaphragmotomy appears safe and increases abdominal exposure of hepatobiliary lesions. The benefit of improved exposure must be carefully weighed up against the risks inherent in inducing pneumothorax.

Biomedical research in developing countries: Opportunities, methods, and challenges

Health research is essential for improving global health, health equity, and economic development. There are vast differences in the disease burden, research budget allocation, and scientific publications between the developed and the low-middle-income countries, which are the homes of 85% of the world's population. There are multiple challenges, as well as opportunities for health research in developing countries. One of the primary reasons for reduced research output from the developing countries is the lack of research capacity. Many developing countries are striving to build their research capacity. They are trying to understand their needs and goals to solve their fundamental health problems, but the opportunity for research education and training remains low. The first joint research meeting of the Bangladesh Gastroenterology Society and the British Society of Gastroenterology took place in February 2020 at the Bangabandhu Sheikh Mujib Medical University in Dhaka, Bangladesh, aimed at providing an overview of medical research for young, aspiring medical researchers. This review article provides an outline of the research day and covers a number of useful topics. This review aims to provide a basic guide for early career researchers, both within the field of gastroenterology and, more generally, to all spheres of medical research.

Changes in epidermal morphology associated with dandruff

OBJECTIVE

Dandruff is a very common scalp condition characterized by flaking and pruritus usually with no visible signs of inflammation, such as redness and erythema. Dandruff is considered a multifactorial condition with both microbial colonization and host factors such as sebum production thought to play a role. There is evidence of changes in epidermal morphology in the scalp skin of dandruff sufferers, with reports of an increase in mean thickness and more nucleated cell layers. The underlying mechanisms driving these morphological changes are currently unclear. The objective of this study was to fully characterize epidermal morphology in dandruff compared to healthy scalp skin and to evaluate potential mechanisms underlying any changes observed.

METHODS

Scalp skin biopsies were taken from 22 healthy female subjects and 21 dandruff sufferers, from both lesional and non-lesional sites. Samples were processed, sectioned and stained using haematoxylin and eosin (H&E). To fully characterize epidermal morphology, measurements were taken of epidermal thickness, the convolution of the dermal-epidermal junction and the depth of epidermal rete ridges. To analyse changes in epidermal proliferation immunohistochemical staining was performed using Ki67, a well-established marker of cell proliferation, and quantified using image analysis.

RESULTS

Histochemical analysis of skin sections revealed that in dandruff lesional samples, the epidermis was thicker, had a more convoluted dermal epidermal junction and the rete ridges were elongated, compared to healthy scalp skin. Similar directional changes in epidermal morphology, were observed in non-lesional dandruff samples, albeit to a lesser extent. Image analysis of Ki67 expression in the epidermis revealed dandruff lesional skin contained significantly more Ki67-positive proliferating keratinocytes than healthy controls samples. This suggests dandruff scalp skin epidermal keratinocytes are in a hyper-proliferative state.

CONCLUSION

There were significant changes in epidermal morphology in dandruff lesional skin compared to healthy scalp skin including increased epidermal thickness, a more convoluted dermal-epidermal junction and elongation of rete ridges. Interestingly, we found there was evidence of an increase in the percentage of epidermal Ki67-positive cells, which has not been reported previously, and demonstrates dandruff is a condition displaying epidermal hyper-proliferation.

Low levels of genetic structuring in King George whiting Sillaginodes punctatus across two geographic regions

Postlarvae of King George whiting Sillaginodes punctatus, a commercially important fish species in southern Australia, were collected from multiple locations across south and south-eastern Australia. Genetic analyses using seven microsatellite markers found little evidence of genetic structure suggesting high levels of connectivity between the regions. The results found no evidence of a distinct source spawning population within the south-eastern range sampled in this study.

HRD1 sensitizes breast cancer cells to Tamoxifen by promoting S100A8 degradation

Estrogen receptor alpha positive (ER+) of breast cancer could develop resistance to antiestrogens including Tamoxifen. Our previous study showed that the E3 ubiquitin ligase HRD1 played an important role in anti-breast cancer. However, its role in chemotherapy resistance hasn't been reported. In this study, we found that HRD1 expression was downregulated in Tamoxifen-resistant breast cancer cell line MCF7/Tam compared to the Tamoxifen sensitive cell line MCF7. Moreover, S100A8 is the direct target of HRD1 by proteome analysis. Our data showed that HRD1 decreased the protein level of S100A8 through ubiquitination while HRD1 was regulated by acetylation of histone. More importantly, HRD1 knockdown significantly increased the cell survival of MCF7 cells to the Tamoxifen treatment. HRD1 overexpression sensitized MCF7/Tam cells to the Tamoxifen treatment in vitro and in vivo. In conclusion, the decrease of HRD1 expression contributed to Tamoxifen resistance in breast cancer.

Abstract 4365: Epigenetic and biological effects of 5-azacytidine and RRX-001 on DLD-1 colorectal cancer cell lines

Introduction. Extramural vascular invasion (EMVI) in rectal tumours is an important risk factor for disease recurrence and death. Recent studies have demonstrated CpG island hypermethylation phenotype (CIMP) to be an independent risk factor for developing EMVI. This study investigates the cellular processes linking hypermethylation with EMVI by an in vitro model of rectal cancer, and assess the biological and epigenetic effects of known and putative demethylating agents.

Methods. Hypermethylated DLD-1 human colorectal cancer cells were cultured for three days and treated daily with demethylating agents 5-azacytidine (AZA) or RRx-001 across a dose range (0.5µM to 5µM). Standard tests of population doubling (RPD) and cytotoxicity (trypan blue) were performed across the dose range for each compound. Treated cells were subjected to a 500µm gel-insert scratch migration assay and video microscopy was used to record time-to-convergence (TC). Methylation specific PCR was performed on harvested cells across the dose range and compared to controls for eight genes associated with CIMP (SOCS1, MINT-1, hMLH, NEUROG1, THBD, HAND1, ADAMTS1, IGFBP3).

Results. 5-azacytidine and RRx-001 both demonstrated &gt;50% reduction in RPD at a dose of 2µM, with a linear dose-dependent retardation of population growth from 0.1µM to 1.0µM. Trypan blue test also demonstrated linear increase in cytotoxicity for both agents up to 1µM. Mean TC was 38.6hrs +/- 2.4hrs (1SD) for control, solvent control (DMSO), and 0.5µM AZA & RRx-001. Mean TC for 1.0µM and 2.0µM AZA was 52.0hrs +/- 3.0hrs and 91.0hrs +/- 3.75hrs, respectively (p=&lt;0.001). Mean TC for 1.0µM and 2.0µM RRx-001 was 57.0hrs +/- 2.0hrs and 96.0hrs +/- 6.0hrs, respectively (p=&lt;0.005).

Both AZA and RRx-001 demethylate 5 out of 8 CpG islands across the dose spectrum. hMLH, SOCS, and IGFBP3 were resistant to demethylation for both compounds at all doses. MINT, HAND, and THBD were partially demethylated by both agents, but ADAMTS1 was demethylated by AZA only. In each of the genes that demonstrated CpG island demethylation the demethylation was incomplete, with strong methylated bands present despite an additional demethylated band also being demonstrated. RRx-001 demonstrated a dose-dependent demethylation of NEUROG1 and THBD as integrated density of demethylated bands decreased against increasing dose of drug.

Conclusions. This study demonstrates the demethylating ability of both agents against the methylome of 5 out of 8 genes associated with CIMP, which is a known to be associated with EMVI; an independent risk factor for poor prognosis in rectal cancers. The biological and demethylating effects occur at doses below those that may be considered cytotoxic, suggesting that demethylation its self is reducing the rate of cell division and migration of cancer cells. Further work is required to quantify the effects of both agents on the methylome of DLD-1 cells, and to explore the mechanisms of action of both compounds.

Citation Format: Rory Kokelaar, Huw Jones, John Beynon, Dean Harris, Gareth Jenkins. Epigenetic and biological effects of 5-azacytidine and RRX-001 on DLD-1 colorectal cancer cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4365. doi:10.1158/1538-7445.AM2017-4365

Extramural vascular invasion and response to neoadjuvant chemoradiotherapy in rectal cancer: Influence of the CpG island methylator phenotype

AIM

To identify whether CpG island methylator phenotype (CIMP) is predictive of response to neoadjuvant chemoradiotherapy (NACRT) and outcomes in rectal cancer.

METHODS

Patients undergoing NACRT and surgical resection for rectal cancer in a tertiary referral centre between 2002-2011 were identified. Pre-treatment tumour biopsies were analysed for CIMP status (high, intermediate or low) using methylation specific PCR. KRAS and BRAF status were also determined using pyrosequencing analysis. Clinical information was extracted from case records and cancer services databases. Response to radiotherapy was measured by tumour regression scores determined upon histological examination of the resected specimen. The relationship between these molecular features, response to NACRT and oncological outcomes were analysed.

RESULTS

There were 160 patients analysed with a median follow-up time of 46.4 mo. Twenty-one (13%) patients demonstrated high levels of CIMP methylation (CIMP-H) and this was significantly associated with increased risk of extramural vascular invasion (EMVI) compared with CIMP-L [8/21 (38%) vs 15/99 (15%), P = 0.028]. CIMP status was not related to tumour regression after radiotherapy or survival, however EMVI was significantly associated with adverse survival (P < 0.001). Intermediate CIMP status was significantly associated with KRAS mutation (P = 0.01). There were 14 (9%) patients with a pathological complete response (pCR) compared to 116 (73%) patients having no or minimal regression after neoadjuvant chemoradiotherapy. Those patients with pCR had median survival of 106 mo compared to 65.8 mo with minimal regression, although this was not statistically significant (P = 0.26). Binary logistic regression analysis of the relationship between EMVI and other prognostic features revealed, EMVI positivity was associated with poor overall survival, advanced “T” stage and CIMP-H but not nodal status, age, sex, KRAS mutation status and presence of local or systemic recurrence.

CONCLUSION

We report a novel association of pre-treatment characterisation of CIMP-H with EMVI status which has prognostic implications and is not readily detectable on pre-treatment histological examination.

Genetic and Epigenetic Intra-tumour Heterogeneity in Colorectal Cancer

INTRODUCTION

Colorectal cancer (CRC) is a highly heterogeneous disease, with pathologically similar cancers having completely different responses to treatment and patient survival. Intra-tumour heterogeneity (defined as distinct morphological and phenotypic differences) has recently been demonstrated to be an important factor in the development and behaviour of cancer cells and can be used to determine response to anticancer therapy.

METHOD

Patients with resected CRC had DNA extracted from eight defined tumour areas which were analysed for two genetic mutations (BRAF and KRAS) and one epigenetic trait (CpG island methylator phenotype/CIMP). Normal adjacent tissue was studied as control.

RESULTS

Twelve patients with CRC were included. Intra-tumoural heterogeneity for KRAS mutation was seen in 2 patients (17%). There was no statistical evidence of CIMP status heterogeneity (p = 0.85), but 6 of the 12 patients (50%) demonstrated at least one heterogeneous area within the tumour.

DISCUSSION

Intra-tumoural heterogeneity for both genetic and epigenetic factors in CRC is more prevalent than previously thought in Stage II and Stage III CRC. This study provides new insight into epigenetic heterogeneity of CRC and supports the development of a more targeted biopsy strategy to support expansion of personalised treatment.

The International SSRI Pharmacogenomics Consortium (ISPC): a genome-wide association study of antidepressant treatment response

Response to treatment with selective serotonin reuptake inhibitors (SSRIs) varies considerably between patients. The International SSRI Pharmacogenomics Consortium (ISPC) was formed with the primary goal of identifying genetic variation that may contribute to response to SSRI treatment of major depressive disorder. A genome-wide association study of 4-week treatment outcomes, measured using the 17-item Hamilton Rating Scale for Depression (HRSD-17), was performed using data from 865 subjects from seven sites. The primary outcomes were percent change in HRSD-17 score and response, defined as at least 50% reduction in HRSD-17. Data from two prior studies, the Pharmacogenomics Research Network Antidepressant Medication Pharmacogenomics Study (PGRN-AMPS) and the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study, were used for replication, and a meta-analysis of the three studies was performed (N=2394). Although many top association signals in the ISPC analysis map to interesting candidate genes, none were significant at the genome-wide level and the associations were not replicated using PGRN-AMPS and STAR*D data. The top association result in the meta-analysis of response represents SNPs 5′ upstream of the neuregulin-1 gene, NRG1 (P = 1.20E - 06). NRG1 is involved in many aspects of brain development, including neuronal maturation and variations in this gene have been shown to be associated with increased risk for mental disorders, particularly schizophrenia. Replication and functional studies of these findings are warranted.

Rotavirus Infection in Normal Nursery: Epidemic and Surveillance

Human rotavirus (HRV) epidemics have not been reported in normal full-term newborn nurseries in the US. This report describes an epidemic from April 27 to May 6, 1982 in which 23 infants were infected. Diagnosis was confirmed with Rotazyme (Abbott) in 82% (23/28 ) of the neonates screened. Five were asymptomatic; in the remaining 18 cases, the symptoms were usually mild and self-limited. Transient shedding of the virus was found in 8% (4/52) of personnel screened, and only one of them was symptomatic. Control measures included the following: strict cohorting, closure of transitional nursery, enteric precautions and wiping of horizontal surfaces with 95% ethyl alcohol which has been shown to be an effective virucidal agent for rotavirus in laboratories. Follow-up in 80 of 108 contact neonates born during the epidemic showed only two mildly symptomatic cases after discharge. During an 11-month period of surveillance, 33% of neonates (1,688/5,054) born at Cook County Hospital were screened for excretion of virus in stools; only 3.6% of infants (61/1,688) were positive by Rotazyme and none were symptomatic. This report suggests that strict measures are helpful in control of HRV epidemic gastroenteritis and asymptomatic shedding need not be as high as the previously reported incidence of 40% to 50%.

Graphene field-effect transistor and its application for electronic sensing

Graphene, because of its excellent mechanical, electrical, chemical, physical properties, sparked great interest to develop and extend its applications. Particularly, graphene based field-effect transistors (GFETs) present exciting and bright prospects for sensing applications due to their greatly higher sensitivity and stronger selectivity. This Review highlights a selection of important topics pertinent to GFETs and their application in electronic sensors. This article begins with a description of the fabrications and characterizations of GFETs, and then introduces the new developments in physical, chemical, and biological electronic detection using GFETs. Finally, several perspective and current challenges of GFETs development are presented, and some proposals are suggested for further development and exploration.

A novel microfluidic system for the rapid analysis of protein thermal stability

We describe a simple microfluidic device for the rapid analysis of protein thermal stability using a novel imaging method.

Wrinkle reduction in post-menopausal women consuming a novel oral supplement: a double-blind placebo-controlled randomized study

Objective

The maintenance of youthful skin appearance is strongly desired by a large proportion of the world's population. The aim of the present study was therefore to evaluate the effect on skin wrinkling, of a combination of ingredients reported to influence key factors involved in skin ageing, namely inflammation, collagen synthesis and oxidative/UV stress. A supplemented drink was developed containing soy isoflavones, lycopene, vitamin C and vitamin E and given to post-menopausal women with a capsule containing fish oil.

Method

We have performed a double-blind randomized controlled human clinical study to assess whether this cocktail of dietary ingredients can significantly improve the appearance of facial wrinkles.

Results

We have shown that this unique combination of micronutrients can significantly reduce the depth of facial wrinkles and that this improvement is associated with increased deposition of new collagen fibres in the dermis.

Conclusion

This study demonstrates that consumption of a mixture of soy isoflavones, lycopene, vitamin C, vitamin E and fish oil is able to induce a clinically measureable improvement in the depth of facial wrinkles following long-term use. We have also shown, for the first time with an oral product, that the improvement is associated with increased deposition of new collagen fibres in the dermis.

Résumé

Resveratrol repressed viability of U251 cells by miR-21 inhibiting of NF-κB pathway

Resveratrol (RSV), a polyphenol, is known to play an important role in inhibiting proliferation and inducing apoptosis of glioma cells. The aim of this study was to explore the mechanism of RSV on U251 cells apoptosis. RSV showed a dose-dependent decrease in U251 cell viability. It could reduce IκB phosphorylation, nuclear P65 protein levels and NF-κB transcriptional activity, which suggested that signaling pathway are involved in RSV-induced apoptosis. In addition, RSV could inhibit miR-21 expression and down-regulation of miR-21 expression could suppress NF-κB activity. Interestingly, over-expression of miR-21 can reverse the effect of RSV on NF-κB activity and apoptosis in U251 cells. These results suggest that RSV can effectively induce apoptosis of U251 cells and modulation of miR-21 possibly contributes to this antitumor action.

Temporal and spatial patterns in ichthyoplankton assemblages in bay and open coastal environments

The larval fish fauna occurring in temperate bay and shelf waters off Victoria, southern Australia, was found to be diverse, comprising taxa from 52 families. The most abundant groups collected were gobiids, tripterygiids, gobiesocids and clupeids. Fish egg concentrations were highest during spring and summer (September to February). Eggs of the Australian anchovy Engraulis australis occurred mainly during spring (September to November). Total larval fish concentrations were highest during summer (December to February), and were significantly higher at 1 km than 2 and 5 km from shore in offshore samples. Larval concentrations of a number of families, mainly reef-associated taxa that attach their eggs to hard substrata, were also higher nearer to shore. These larvae are more developed upon hatching than those of pelagic spawners and more capable of avoiding passive drift. Multivariate analyses found that larval taxonomic composition did not vary significantly with distance from shore, but that seasonal and monthly groupings were evident, with different taxa dominating at different times of the year. Larvae of the families Gobiidae and Tripterygiidae occurred in all months, but were less abundant during winter. Spatial differences in the larval fish assemblage between offshore samples and samples taken in the bay were only apparent during summer. This was primarily due to a higher abundance of seagrass-associated species, such as syngnathids and hemiramphids, utilizing specific habitats in the bay.

Rapid prototyping of PDMS devices using SU-8 lithography

This protocol describes the fabrication of single and multi-layer SU-8 microstructures for generating microfluidic devices via PDMS (polymethyldisiloxane) casting. SU-8 is a negative, thick-film, epoxy based photoresist that has become widespread in the MEMS industry for producing durable, high aspect ratio microstructures for a variety of applications. It has become especially popular with microfluidics researchers to produce molds for PDMS casting since such molds allow for the rapid replication of prototype microfluidic structures made from PDMS. Although SU-8 processing does allow for rapid and straightforward development of devices it is prone to numerous pitfalls which have gained it a reputation of being somewhat of a "black art." This protocol attempts to give as full an account as possible of all the tricks and tips the author has learned over the years for processing SU-8. It also describes the casting of PDMS and plasma bonding for the generation of complete microfluidic devices ready for use in the lab.

Measurement of granulocyte pharmacodynamics in whole blood by flow cytometry

During the Phase I/II assessment of new therapies with the potential to suppress eosinophil and neutrophil inflammation, there is a need to assess the peripheral blood pharmacokinetic (PK) and pharmacodynamic (PD) profiles of the drug. This has relevance in respiratory disease since drugs that target eosinophillic inflammation are in development for asthma; whereas neutrophil-directed therapies are being introduced for treatment of chronic obstructive airways disease (COPD). Pharmacokinetic evaluation is required to determine the concentration of drug substance (and possibly metabolites) in peripheral blood at intervals following single or repeated dosing. Pharmacodynamic assessment is also required since many drug substances have a duration of action which is prolonged beyond the time when drug substance is detectable in the blood (see Fig. 1). Fig. 1. Whole blood pharmacodynamics. In preclinical studies, animal or human blood is treated with test agents. In clinical studies, human subjects are treated with drug and blood removed for analysis. GAFS, gated autofluorescence forward scatter; PK, pharmacokinetics; PD, pharmacoldynamics.