High preoperative levels of circulating SFRP5 predict better prognosis in colorectal cancer patients.

The purpose of this research was to investigate the diagnostic and prognostic value of circulating SFRP5 (cSFRP5) in colorectal cancer (CRC). We evaluated preoperative cSFRP5 levels in CRC patients and controls (n = 208). We found significantly higher cSFRP5 levels in CRC patients compared with non-CRC controls (p < 0.001). Levels of cSFRP5 were significantly lower in CRC patients with either vascular invasion (p = 0.001) or liver metastasis (p = 0.016). High cSFRP5 levels were associated with longer disease-free survival in both univariate (p = 0.024) and multivariate (p = 0.015) analyses. Analysis of an independent tissue cohort from The Cancer Genome Atlas database revealed significantly lower SFRP5 RNA expression in CRC tumor tissue compared with adjacent normal mucosa (n = 590 vs 47; p < 0.0001). Our findings confirm the role of cSFRP5 as a physiologic tumor suppressor and demonstrate its potential diagnostic and prognostic value in CRC.

Experiences of Weight-Loss Surgery in People With Serious Mental Illness: A Qualitative Study.

BACKGROUND: Bariatric surgery is seldom accessed by people with serious mental illness, despite high rates of obesity in this population. It is sometimes assumed that patients with complex psychiatric histories will have poor post-surgical weight loss or exacerbation of psychiatric symptoms, although this is unsubstantiated. OBJECTIVES: A qualitative descriptive study to explore personal experiences and the impact of bariatric surgery on physical and mental well-being and life-quality in individuals with serious mental illness. METHODS: Nine adults with a history of bariatric surgery and concurrent severe depressive disorder, bipolar disorder, or schizoaffective disorder were interviewed about their experiences of bariatric surgery and its outcomes using semi-structured interview schedules. Data were transcribed and inductive thematic analysis undertaken. RESULTS: Five broad themes emerged: (1) surgery was highly effective for weight loss, and resulted in subjective improvements in physical health, quality of life, and mental health described as being able to live a life; (2) recovering from surgery was a tough road, notably in the post-operative period where negative sequelae often anteceded benefits; (3) post-operative support was important, but sometimes insufficient, including from families, mental health services, and surgical teams; (4) most considered surgery life-changing, recommending it to others with mental illness and obesity, two had different experiences; (5) participants considered it discriminatory that people with mental illness were not referred or declined weight loss surgery. CONCLUSIONS: Participants benefited from bariatric surgery and felt it should be offered to others with mental illness, but with additional care and support.

MicroRNA Profiling in Adipose Before and After Weight Loss Highlights the Role of miR-223-3p and the NLRP3 Inflammasome.

OBJECTIVE: Adipose tissue plays a key role in obesity-related metabolic dysfunction. MicroRNA (miRNA) are gene regulatory molecules involved in intercellular and inter-organ communication. It was hypothesized that miRNA levels in adipose tissue would change after gastric bypass surgery and that this would provide insights into their role in obesity-induced metabolic dysregulation. METHODS: miRNA profiling (Affymetrix GeneChip miRNA 2.0 Array) of omental and subcutaneous adipose (n = 15 females) before and after gastric bypass surgery was performed. RESULTS: One omental and thirteen subcutaneous adipose miRNAs were significantly differentially expressed after gastric bypass, including downregulation of miR-223-3p and its antisense relative miR-223-5p in both adipose tissues. mRNA levels of miR-223-3p targets NLRP3 and GLUT4 were decreased and increased, respectively, following gastric bypass in both adipose tissues. Significantly more NLRP3 protein was observed in omental adipose after gastric bypass (P = 0.02). Significant hypomethlyation of NLRP3 and hypermethylation of miR-223 were observed in both adipose tissues after gastric bypass. In subcutaneous adipose, significant correlations were observed between both miR-223-3p and miR-223-5p and glucose and between NLRP3 mRNA and protein levels and blood lipids. CONCLUSIONS: This is the first report detailing genome-wide miRNA profiling of omental adipose before and after gastric bypass, and it further highlights the association of miR-223-3p and the NLRP3 inflammasome with obesity.

Assessment of the Dynamic Insulin Secretion and Sensitivity Test (DISST) Pre and Post Gastric bypass Surgery.

OBJECTIVE: To compare the dynamic insulin secretion and sensitivity test (DISST) with the euglycaemic clamp in individuals undergoing open Roux-en-Y gastric bypass (RYGB) surgery prior-to and one month after surgery. METHODS: Insulin sensitivity in individuals with obesity undergoing RYGB was studied with DISST and a euglycaemic hyperinsulinaemic clamp. RESULTS: Eleven participants, including nine females, mean(SD) age 51.2 (12.1) yrs, with a preoperative BMI of 48.7(9.5)kg/m2 were studied. Weight reduced from a mean (SD) of 133.8 (29.8) kg to 123.8 (28.9) kg post-surgery (p<0.001). The mean (SD) insulin sensitivity index (ISI-DISST) was 3.07×10-4 (2.18) L.pmol-1.min-1 preoperatively and 2.36 ×10-4 (0.78)L.pmol-1.min-1 postoperatively (p=0.37). The mean(SD) clamp ISI was 2.14 ×10-2 (1.80) mg.L.kg-1.min-1.pmol-1 and 2.00×10-2.(0.76) mg.L.kg-1.min-1.pmol-1 postoperatively (p=0.86). Correlation between ISI-DISST and ISI-Clamp preoperatively was r=0.81(95%CI 0.37-0.95) and post-operatively r=0.47(95%CI 0-0.88). Bland-Altman analysis demonstrates systematic bias between the two tests, where DISST underestimated insulin sensitivity compared with the clamp by 0.96×10-2.mg.L.kg-1.min-1.pmol-1 (95%CI -2.24 to 0.32). CONCLUSIONS: There was a strong correlation between DISST and the clamp preoperatively and DISST can be used to estimate insulin sensitivity in individuals with morbid obesity. After RYGB surgery, DISST had a weaker correlation with the clamp suggesting the fundamental physiological determinants of insulin sensitivity being measured by each method change in different ways with changes in glucose homeostasis following RYGB surgery.

Combination of laser microdissection, 2D-DIGE and MALDI-TOF MS to identify protein biomarkers to predict colorectal cancer spread.

Biomarkers are urgently required to support current histological staging to provide additional accuracy in stratifying colorectal cancer (CRC) patients according to risk of spread to properly assign adjuvant chemotherapy after surgery. Chemotherapy is given to patients with stage III to reduce the risk of recurrence but is controversial in stage II patients. Up to 25% of stage II patients will relapse within 5 years after tumor removal and when this occurs cure is seldom possible. The aim of this study was to identify protein biomarkers to stratify risk of spread of CRC patients. Laser micro-dissection was used to isolate cancer cells from primary colorectal tumors of stage II patients which did or did not metastasize within 5 years after surgical resection. Protein expression differences between two groups of tumors were profiled by 2D-DIGE with saturation CyDye labeling and identified using MALDI-TOF mass spectrometry. Evaluation of protein candidates was conducted using tissue micro array (TMA) immunohistochemistry on 125 colorectal tumor tissue samples of different stages. A total of 55 differentially expressed proteins were identified. Ten protein biomarkers were chosen based on p value and ratio between non metastasized and metastazised groups and evaluated on 125 tissues using TMA immunohistochemistry. Expression of HLAB, protein 14-3-3ß, LTBP3, ADAMTS2, JAG2 and NME2 on tumour cells was significantly associated with clinical parameters related to tumour progression, invasion and metastasis. Kaplan-Meier survival curve showed strong expression of six proteins was associated with good CRC specific survival. Expression of HLAB, ADAMTS2, LTBP3, JAG2 and NME2 on tumour cells, was associated with tumour progression and invasion, metastasis and CRC specific survival may serve as potential biomarkers to stratify CRC patients into low and high risk of tumour metastasis. Combined methods of laser microdissection, 2D DIGE with saturation labelling and MALDI-TOF MS proved to be resourceful techniques capable of identifying protein biomarkers to predict risk of spread of CRC to liver.

Oxidative modifications of mitochondrial complex II are associated with insulin resistance of visceral fat in obesity.

Obesity, particularly visceral adiposity, has been linked to mitochondrial dysfunction and increased oxidative stress, which have been suggested as mechanisms of insulin resistance. The mechanism(s) behind this remains incompletely understood. In this study, we hypothesized that mitochondrial complex II dysfunction plays a role in impaired insulin sensitivity in visceral adipose tissue of subjects with obesity. We obtained subcutaneous and visceral adipose tissue biopsies from 43 subjects with obesity (body mass index ≥ 30 kg/m2) during planned bariatric surgery. Compared with subcutaneous adipose tissue, visceral adipose tissue exhibited decreased complex II activity, which was restored with the reducing agent dithiothreitol (5 mM) ( P < 0.01). A biotin switch assay identified that cysteine oxidative posttranslational modifications (OPTM) in complex II subunit A (succinate dehydrogenase A) were increased in visceral vs. subcutaneous fat ( P < 0.05). Insulin treatment (100 nM) stimulated complex II activity in subcutaneous fat ( P < 0.05). In contrast, insulin treatment of visceral fat led to a decrease in complex II activity ( P < 0.01), which was restored with addition of the mitochondria-specific oxidant scavenger mito-TEMPO (10 µM). In a cohort of 10 subjects with severe obesity, surgical weight loss decreased OPTM and restored complex II activity, exclusively in the visceral depot. Mitochondrial complex II may be an unrecognized and novel mediator of insulin resistance associated with visceral adiposity. The activity of complex II is improved by weight loss, which may contribute to metabolic improvements associated with bariatric surgery.

miRNA Signatures of Insulin Resistance in Obesity.

OBJECTIVE: Extracellular microRNAs (miRNAs) represent functional biomarkers for obesity and related disorders; this study investigated plasma miRNAs in insulin resistance phenotypes in obesity. METHODS: One hundred seventy-five miRNAs were analyzed in females with obesity (insulin sensitivity, n = 11; insulin resistance, n = 19; type 2 diabetes, n = 15) and without obesity (n = 12). Correlations between miRNA level and clinical parameters and levels of 15 miRNAs in a murine obesity model were investigated. RESULTS: One hundred six miRNAs were significantly (adjusted P ≤ 0.05) different between controls and at least one obesity phenotype, including miRNAs with the following attributes: previously reported roles in obesity and altered circulating levels (e.g., miR-122, miR-192); known roles in obesity but no reported changes in circulating levels (e.g., miR-378a); and no current reported role in, or association with, obesity (e.g., miR-28-5p, miR-374b, miR-32). The miRNAs in the latter group were found to be associated with extracellular vesicles. Forty-eight miRNAs showed significant correlations with clinical parameters; stepwise regression retained let-7b, miR-144-5p, miR-34a, and miR-532-5p in a model predictive of insulin resistance (R2 = 0.57, P = 7.5 × 10-8 ). Both miR-378a and miR-122 were perturbed in metabolically relevant tissues in a murine model of obesity. CONCLUSIONS: This study expands on the role of extracellular miRNAs in insulin-resistant phenotypes of obesity and identifies candidate miRNAs not previously associated with obesity.

The Post-SIR-Spheres Surgery Study (P4S): Retrospective Analysis of Safety Following Hepatic Resection or Transplantation in Patients Previously Treated with Selective Internal Radiation Therapy with Yttrium-90 Resin Microspheres.

BACKGROUND: Reports show that selective internal radiation therapy (SIRT) may downsize inoperable liver tumors to resection or transplantation, or enable a bridge-to-transplant. A small-cohort study found that long-term survival in patients undergoing resection following SIRT appears possible but no robust studies on postsurgical safety outcomes exist. The Post-SIR-Spheres Surgery Study was an international, multicenter, retrospective study to assess safety outcomes of liver resection or transplantation following SIRT with yttrium-90 (Y-90) resin microspheres (SIR-Spheres®; Sirtex). METHODS: Data were captured retrospectively at participating SIRT centers, with Y-90 resin microspheres, surgery (resection or transplantation), and follow-up for all eligible patients. Primary endpoints were perioperative and 90-day postoperative morbidity and mortality. Standard statistical methods were used. RESULTS: The study included 100 patients [hepatocellular carcinoma: 49; metastatic colorectal cancer (mCRC): 30; cholangiocarcinoma, metastatic neuroendocrine tumor, other: 7 each]; 36% of patients had one or more lines of chemotherapy pre-SIRT. Sixty-three percent of patients had comorbidities, including hypertension (44%), diabetes (26%), and cardiopathy (16%). Post-SIRT, 71 patients were resected and 29 received a liver transplant. Grade 3+ peri/postoperative complications and any grade of liver failure were experienced by 24 and 7% of patients, respectively. Four patients died <90 days postsurgery; all were trisectionectomies (mCRC: 3; cholangiocarcinoma: 1) and typically had one or more previous chemotherapy lines and presurgical comorbidities. CONCLUSIONS: In 100 patients undergoing liver surgery after receiving SIRT, mortality and complication rates appeared acceptable given the risk profile of the recruited patients.

Genome-wide DNA methylation analysis reveals loci that distinguish different types of adipose tissue in obese individuals.

BACKGROUND: Epigenetic mechanisms provide an interface between environmental factors and the genome and are known to play a role in complex diseases such as obesity. These mechanisms, including DNA methylation, influence the regulation of development, differentiation and the establishment of cellular identity. Here we employ two approaches to identify differential methylation between two white adipose tissue depots in obese individuals before and after gastric bypass and significant weight loss. We analyse genome-wide DNA methylation data using (a) traditional paired t tests to identify significantly differentially methylated loci (Bonferroni-adjusted P ≤ 1 × 10-7) and (b) novel combinatorial algorithms to identify loci that differentiate between tissue types. RESULTS: Significant differential methylation was observed for 3239 and 7722 CpG sites, including 784 and 1129 extended regions, between adipose tissue types before and after significant weight loss, respectively. The vast majority of these extended differentially methylated regions (702) were consistent across both time points and enriched for genes with a role in transcriptional regulation and/or development (e.g. homeobox genes). Other differentially methylated loci were only observed at one time point and thus potentially highlight genes important to adipose tissue dysfunction observed in obesity. Strong correlations (r > 0.75, P ≤ 0.001) were observed between changes in DNA methylation (subcutaneous adipose vs omentum) and changes in clinical trait, in particular for CpG sites within PITX2 and fasting glucose and four CpG sites within ISL2 and HDL. A single CpG site (cg00838040, ATP2C2) gave strong tissue separation, with validation in independent subcutaneous (n = 681) and omental (n = 33) adipose samples. CONCLUSIONS: This is the first study to report a genome-wide DNA methylome comparison of subcutaneous abdominal and omental adipose before and after weight loss. The combinatorial approach we utilised is a powerful tool for the identification of methylation loci that strongly differentiate between these tissues. This study provides a solid basis for future research focused on the development of adipose tissue and its potential dysfunction in obesity, as well as the role DNA methylation plays in these processes.

Soluble HLA-G is a differential prognostic marker in sequential colorectal cancer disease stages.

The expression of HLA-G by tumour cells is an established mechanism to escape recognition and immune mediated destruction, allowing tumour survival, growth and metastasis. However, the prognostic value of soluble HLA-G (sHLA-G) remains unknown. Mucinous carcinoma (MC) is a distinct form of colorectal cancer (CRC) found in 10 to 15% of patients, which has long been associated with poor response to treatment. To investigate the prognostic value of plasma sHLA-G levels in CRC patients, preoperative plasma sHLA-G levels were determined by ELISA in CRC patients (n = 133). In addition, the local expression of HLA-G in tumour biopsies was assessed using tissue microarray analysis (n = 255). Within the high 33rd percentile of sHLA-G levels (265-890 U/mL; n = 44) we observed higher frequency of MC patients (p = 0.012; Chi-square), and higher sHLA-G levels in patients with vascular invasion (p = 0.035; two-tailed t-test). Moreover, MC patients had significantly higher sHLA-G levels compared to those with adenocarcinoma not otherwise specified (p = 0.036; two-tailed t-test). Surprisingly, while stage II patients showed negative correlation between sHLA-G levels and liver metastasis free survival (LMFS) (p = 0.041; R = -0.321), in stage III patients high sHLA-G levels were associated with significantly longer LMFS (p = 0.002), and sHLA-G levels displayed positive correlation with LMFS (p = 0.006; R = 0.409). High HLA-G expression in tumours was associated with poor cancer specific overall survival in stage II to III (p = 0.01), and with shorter LMFS in stage II patients (p = 0.004). Our findings reveal that sHLA-G levels are associated with distinct progression patterns in consecutive disease stages, indicating a potential value as surrogate marker in the differential prognosis of CRC.

Aberrant liver insulin receptor isoform a expression normalises with remission of type 2 diabetes after gastric bypass surgery.

Type 2 diabetes mellitus (T2DM) results from a combination of progressive insulin resistance and loss of pancreatic beta cell function and/or mass. Insulin signalling occurs through the insulin receptor, (INSR) which is alternatively spliced into two isoforms: INSRA (-exon 11) and INSRB (+exon 11). Because the INSR isoforms have different functional characteristics, their relative expression ratio has been implicated in the pathogenesis of insulin resistance and T2DM. We studied levels of INSR isoform mRNA in liver samples taken from 46 individuals with or without T2DM at Roux-en-Y (RYGB) surgery, and on average 17 (± 5.6) months later in 16 of the same individuals (8 diabetic and non-diabetic patients). INSRA or INSRB was also overexpressed in HepG2 cells to ascertain their effect on AKT phosphorylation and PCK1 expression as markers of insulin-mediated metabolic signalling. We found the INSRB:A isoform ratio was reduced in individuals with T2DM in comparison to those with normal glucose tolerance and normalised with remission of diabetes. The INSRB:A ratio increased due to a reduction in the alternatively spliced INSRA isoform following remission of diabetes. Overexpressing INSRA isoform in HepG2 hepatoma cells reduced inhibition of PCK1 transcription and did not increase AKT phosphorylation in response to insulin load compared to the effect of overexpressing the B isoform. Data presented here revitalizes the role of the INSR isoforms in the pathogenesis of T2DM, and suggests that an abrogated INSRB:A ratio that favours the INSRA isoform may negatively impact insulin-mediated metabolic signalling.

Alpha-enolase is upregulated on the cell surface and responds to plasminogen activation in mice expressing a ∆133p53α mimic.

The p53 protein is a master regulator of the stress response. It acts as a tumor suppressor by inducing transcriptional activation of p53 target genes, with roles in apoptosis, cell cycle arrest and metabolism. The discovery of at least 12 isoforms of p53, some of which have tumor-promoting properties, has opened new avenues of research. Our previous work studied tumor phenotypes in four mouse models with different p53 backgrounds: wild-type p53, p53 null, mutant p53 lacking the proline domain (mΔpro), and a mimic for the human Δ133p53α p53 isoform (Δ122p53). To identify the major proteins affected by p53 function early in the response to DNA damage, the current study investigated the entire proteome of bone marrow, thymus, and lung in the four p53 models. Protein extracts from untreated controls and those treated with amsacrine were analyzed using two-dimensional fluorescence difference gel electrophoresis. In the bone marrow, reactive proteins were universally decreased by wild-type p53, including α-enolase. Further analysis of α-enolase in the p53 models revealed that it was instead increased in Δ122p53 hematopoietic and tumor cell cytosol and on the cell surface. Alpha-enolase on the surface of Δ122p53 cells acted as a plasminogen receptor, with tumor necrosis factor alpha induced upon plasminogen stimulation. Taken together, these data identified new proteins associated with p53 function. One of these proteins, α-enolase, is regulated differently by wild-type p53 and Δ122p53 cells, with reduced abundance as part of a wild-type p53 response and increased abundance with Δ122p53 function. Increased cell surface α-enolase on Δ122p53 cells provides a possible explanation for the model's pro-inflammatory features and suggests that p53 isoforms may direct an inflammatory response by increasing the amount of α-enolase on the cell surface.

An analysis of DNA methylation in human adipose tissue reveals differential modification of obesity genes before and after gastric bypass and weight loss.

BACKGROUND: Environmental factors can influence obesity by epigenetic mechanisms. Adipose tissue plays a key role in obesity-related metabolic dysfunction, and gastric bypass provides a model to investigate obesity and weight loss in humans. RESULTS: Here, we investigate DNA methylation in adipose tissue from obese women before and after gastric bypass and significant weight loss. In total, 485,577 CpG sites were profiled in matched, before and after weight loss, subcutaneous and omental adipose tissue. A paired analysis revealed significant differential methylation in omental and subcutaneous adipose tissue. A greater proportion of CpGs are hypermethylated before weight loss and increased methylation is observed in the 3' untranslated region and gene bodies relative to promoter regions. Differential methylation is found within genes associated with obesity, epigenetic regulation and development, such as CETP, FOXP2, HDAC4, DNMT3B, KCNQ1 and HOX clusters. We identify robust correlations between changes in methylation and clinical trait, including associations between fasting glucose and HDAC4, SLC37A3 and DENND1C in subcutaneous adipose. Genes investigated with differential promoter methylation all show significantly different levels of mRNA before and after gastric bypass. CONCLUSIONS: This is the first study reporting global DNA methylation profiling of adipose tissue before and after gastric bypass and associated weight loss. It provides a strong basis for future work and offers additional evidence for the role of DNA methylation of adipose tissue in obesity.

Effects of bariatric surgery on untreated lower urinary tract symptoms: a prospective multicentre cohort study.

OBJECTIVE: To evaluate the effects of bariatric surgery on lower urinary tract symptoms (LUTS) in a prospective cohort study. PATIENTS AND METHODS: Patients undergoing bariatric surgery were recruited into the study. LUTS were assessed using the International Prostate Symptoms Score (IPSS) in men and Bristol Female Lower Urinary Tract Symptoms Score Questionnaire (BFLUTS) in women. Serum glucose, insulin and prostate-specific antigen (PSA) levels were recorded; insulin resistance was quantified using the Homeostasis Model Assessment (HOMA-IR) method. Patients were assessed before surgery, and at 6-8 weeks and 1 year after surgery. Weight loss, change in body mass index (BMI), total symptoms score as well as individual symptoms were tested for statistical significance with correction for multiple testing using Bonferroni method. Linear regression analysis was performed with total symptoms score change at 1 year as the outcome variable and BMI, age, total symptoms score before surgery, HOMA-IR, glucose level before surgery, insulin level before surgery, change in insulin level after surgery, weight loss and BMI loss as predictor variables. RESULTS: In all, 86 patients were recruited and 82% completed at least one follow-up after surgery. There was significant weight loss and reduction of BMI after surgery (P < 0.001). At 6 weeks, there was a significant reduction in overall symptom score (P < 0.001) and this improvement was sustained at 1 year. Linear regression analysis showed that total symptoms score at baseline, HOMA-IR, preoperative insulin level and change in insulin level postoperatively were predictive of the change in total symptoms score while the amount of weight loss was not. CONCLUSIONS: The study confirms the improvement in LUTS after weight loss but there is no correlation between the improvement and the time course or degree of weight loss. Rather there is a suggestion that the improvement in symptoms is linked to improvement in insulin resistance seen as a result of both bariatric surgery and weight loss.

Liver ENPP1 protein increases with remission of type 2 diabetes after gastric bypass surgery.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is a progressive disease resulting from increasing insulin resistance and reduced pancreatic ß-cell insulin secretion. Ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) inhibits insulin signalling and may contribute to the pathogenesis of T2DM. Others have found elevated ENPP1 levels in muscle, fat, and skin tissues from insulin resistant individuals, but similar data on liver ENPP1 is lacking. The purpose of this study was to compare expression and protein concentrations of ENPP1 in liver between patients with and without T2DM. METHODS: Roux-en-Y gastric bypass surgery (RYGB) results in remission of insulin resistance and T2DM thus presenting an opportunity to examine some critical aspects of these conditions. We measured liver ENPP1 gene and protein expression in individuals with or without T2DM at RYGB and on average 17 (±5.6) months later. RESULTS: We found liver ENPP1 protein abundance was lower in individuals with T2DM than in those with normal glucose tolerance, and increased after RYGB surgery in those individuals who had remission of T2DM. ENPP1 positively correlated with insulin sensitivity at the liver (as measured by HOMA-IR), which is contrary to what others have reported in other insulin target tissues. CONCLUSIONS: Liver ENPP1 expression in T2DM is the reverse of that expected based on expression in other tissues and is likely due to the unique role the liver has in insulin clearance. The work presented here adds another dimension to the role of ENPP1, and supports the hypothesis that ENPP1 may act as a natural modulator of insulin signalling in the liver.

Insulin receptor-insulin interaction kinetics using multiplex surface plasmon resonance.

Type 2 diabetes affects millions of people worldwide, and measuring the kinetics of insulin receptor-insulin interactions is critical to improving our understanding of this disease. In this paper, we describe, for the first time, a rapid, real-time, multiplex surface plasmon resonance (SPR) assay for studying the interaction between insulin and the insulin receptor ectodomain, isoform A (eIR-A). We used a scaffold approach in which anti-insulin receptor monoclonal antibody 83-7 (Abcam, Cambridge, UK) was first immobilized on the SPR sensorchip by amine coupling, followed by eIR-A capture. The multiplex SPR system (ProteOn XPR36™, Bio-Rad Laboratories, Hercules, CA) enabled measurement of replicate interactions with a single, parallel set of analyte injections, whereas repeated regeneration of the scaffold between measurements caused variable loss of antibody activity. Interactions between recombinant human insulin followed a two-site binding pattern, consistent with the literature, with a high-affinity site (dissociation constant K(D1) = 38.1 ± 0.9 nM) and a low-affinity site (K(D2) = 166.3 ± 7.3 nM). The predominantly monomeric insulin analogue Lispro had corresponding dissociation constants K(D1) = 73.2 ± 1.8 nM and K(D2) = 148.9 ± 6.1 nM, but the fit to kinetic data was improved when we included a conformational change factor in which the high-affinity site was converted to the low-affinity site. The new SPR assay enables insulin-eIR-A interactions to be followed in real time and could potentially be extended to study the effects of humoral factors on the interaction, without the need for insulin labeling.

Service evaluation of weight outcomes as a function of initial BMI in 34,271 adults referred to a primary care/commercial weight management partnership scheme.

BACKGROUND: It is not clear if behaviour change programmes are more or less effective for weight management in people with high BMIs than for those who are moderately overweight. An earlier service evaluation reported on the rate and extent of weight loss in a primary care/commercial weight management organisation partnership scheme, in 34,271 patients were referred by their health care professionals to a UK commercial weight management organisation, Slimming World for 12 weekly sessions. This project updated that service evaluation by examining weight loss outcomes as a function of initial BMI in the same 34,271 patients. FINDINGS: Patients referred to the scheme (n = 34,271) were categorised by BMI groups <30 kg/m(2), 30-34.9 kg/m(2), 35-39.9 kg/m(2) and to ≥ 40 kg/m(2). Mean weight losses after 12 weekly sessions were 2.9, 3.6, 4.1, and 4.8 kg for each BMI category respectively. Regression analysis showed that after adjusting for age and gender, relative to the <30 kg/m(2) group, absolute weight losses were 0.8, 1.4 and 2.4 kg more for the 30-34.9 kg/m(2), 35-39.9 kg/m(2) and to ≥ 40 kg/m(2) groups, respectively (all p<0.001). Percent weight loss was similar in each BMI category: 3.7%, 4.0%, 4.0% and 3.9%, respectively (p<0.001). CONCLUSIONS: This service evaluation demonstrates that 12 week referral to a commercial organisation is as effective for people with high BMIs as for those who are moderately overweight.

Overexpression of aminoacylase 1 is associated with colorectal cancer progression.

Aminoacylase 1 (ACY1) is a cytosolic enzyme responsible for amino acid deacylation during intracellular protein degradation. ACY1 has been implicated in a number of human tumor types. However, the exact role of ACY1 in tumor development remains elusive because it was found to be lost in small cell lung cancer and renal cell carcinoma but overexpressed in colorectal cancer (CRC). The present study aims to further clarify the relationship of ACY1 with CRC progression. Immunohistochemical staining was performed in tissue microarrays composed of 120 cases of CRC using a monoclonal anti-ACY1 antibody. Immunoreactivity was analyzed in association with patients' clinicopathologic parameters and survival time. The role of ACY1 in cell proliferation and apoptosis was assessed by silencing its expression in HCT116 cells using a small interfering RNA. Strong expression of ACY1 was found to be significantly associated with more advanced TNM stage, lymph node metastasis, positive vascular invasion, and shorter cancer-specific survival. ACY1 knockdown significantly inhibited cell proliferation and induced apoptosis. We concluded that ACY1 expression in CRC varies with stage and appears to play a role in cell proliferation and apoptosis. Further evaluation of ACY1 as a clinically useful prognostic marker and a potential drug target for CRC would seem worthwhile.

Cathepsin D Expression in Colorectal Cancer: From Proteomic Discovery through Validation Using Western Blotting, Immunohistochemistry, and Tissue Microarrays.

Despite recent advances in surgical techniques and therapeutic treatments, survival from colorectal cancer (CRC) remains disappointing with some 40-50% of newly diagnosed patients ultimately dying of metastatic disease. Current staging by light microscopy alone is not sufficiently predictive of prognosis and would benefit from additional support from biomarkers in order to stratify patients appropriately for adjuvant therapy. We have identified that cathepsin D expression was significantly greater in cells from invasive front (IF) area and liver metastasis (LM) than those from main tumour body (MTB). Cathepsin D expression was subsequently examined by immunohistochemistry in tissue microarrays from 119 patients with CRC. Strong expression in tumour cells at the IF did not correlate significantly with any clinico-pathological parameters examined or patient survival. However, cathepsin D expression in cells from the MTB was highly elevated in late stage CRC and showed significant correlation with subsequent distant metastasis and shorter cancer-specific survival. We also found that macrophages surrounding tumour cells stained strongly for cathepsin D but there was no significant correlation found between cathepsin D in macrophages at IF and MTB of CRC patient with the clinic-pathological parameters examined.