Cognitive function in early-phase schizophrenia-spectrum disorder: IQ subtypes, brain volume and immune markers.

BACKGROUND: Evidence suggests that cognitive subtypes exist in schizophrenia that may reflect different neurobiological trajectories. We aimed to identify whether IQ-derived cognitive subtypes are present in early-phase schizophrenia-spectrum disorder and examine their relationship with brain structure and markers of neuroinflammation. METHOD: 161 patients with recent-onset schizophrenia spectrum disorder (<5 years) were recruited. Estimated premorbid and current IQ were calculated using the Wechsler Test of Adult Reading and a 4-subtest WAIS-III. Cognitive subtypes were identified with k-means clustering. Freesurfer was used to analyse 3.0 T MRI. Blood samples were analysed for hs-CRP, IL-1RA, IL-6 and TNF-α. RESULTS: Three subtypes were identified indicating preserved (PIQ), deteriorated (DIQ) and compromised (CIQ) IQ. Absolute total brain volume was significantly smaller in CIQ compared to PIQ and DIQ, and intracranial volume was smaller in CIQ than PIQ (F(2, 124) = 6.407, p = 0.002) indicative of premorbid smaller brain size in the CIQ group. CIQ had higher levels of hs-CRP than PIQ (F(2, 131) = 5.01, p = 0.008). PIQ showed differentially impaired processing speed and verbal learning compared to IQ-matched healthy controls. CONCLUSIONS: The findings add validity of a neurodevelopmental subtype of schizophrenia identified by comparing estimated premorbid and current IQ and characterised by smaller premorbid brain volume and higher measures of low-grade inflammation (CRP).

Inflammatory subgroups of schizophrenia and their association with brain structure: A semi-supervised machine learning examination of heterogeneity.

OBJECTIVE: Immune system dysfunction is hypothesised to contribute to structural brain changes through aberrant synaptic pruning in schizophrenia. However, evidence is mixed and there is a lack of evidence of inflammation and its effect on grey matter volume (GMV) in patients. We hypothesised that inflammatory subgroups can be identified and that the subgroups will show distinct neuroanatomical and neurocognitive profiles. METHODS: The total sample consisted of 1067 participants (chronic patients with schizophrenia n = 467 and healthy controls (HCs) n = 600) from the Australia Schizophrenia Research Bank (ASRB) dataset, together with 218 recent-onset patients with schizophrenia from the external Benefit of Minocycline on Negative Symptoms of Psychosis: Extent and Mechanism (BeneMin) dataset. HYDRA (HeterogeneitY through DiscRiminant Analysis) was used to separate schizophrenia from HC and define disease-related subgroups based on inflammatory markers. Voxel-based morphometry and inferential statistics were used to explore GMV alterations and neurocognitive deficits in these subgroups. RESULTS: An optimal clustering solution revealed five main schizophrenia groups separable from HC: Low Inflammation, Elevated CRP, Elevated IL-6/IL-8, Elevated IFN-γ, and Elevated IL-10 with an adjusted Rand index of 0.573. When compared with the healthy controls, the IL-6/IL-8 cluster showed the most widespread, including the anterior cingulate, GMV reduction. The IFN-γ inflammation cluster showed the least GMV reduction and impairment of cognitive performance. The CRP and the Low Inflammation clusters dominated in the younger external dataset. CONCLUSIONS: Inflammation in schizophrenia may not be merely a case of low vs high, but rather there are pluripotent, heterogeneous mechanisms at play which could be reliably identified based on accessible, peripheral measures. This could inform the successful development of targeted interventions.

Time to re-evaluate the risks and benefits of valproate and a call for action.

Valproate is widely used in psychiatry and neurology, including off-label use. Here we consider its potential benefits and risks, particularly for women of childbearing potential, and the evidence that clinical guidelines are adhered to. Finally, we consider the implications for clinical practice and research into its efficacy in off-label indications.

Longitudinal monitoring of neutral and adaptive genomic diversity in a reintroduction.

Restoration programs in the form of ex-situ breeding combined with reintroductions are becoming critical to counteract demographic declines and species losses. Such programs are increasingly using genetic management to improve conservation outcomes. However, the lack of long-term monitoring of genetic indicators following reintroduction prevents assessments of the trajectory and persistence of reintroduced populations. We carried out an extensive monitoring program in the wild for a threatened small-bodied fish (southern pygmy perch, Nannoperca australis) to assess the long-term genomic effects of its captive breeding and reintroduction. The species was rescued prior to its extirpation from the terminal lakes of Australia's Murray-Darling Basin, and then used for genetically informed captive breeding and reintroductions. Subsequent annual or biannual monitoring of abundance, fitness, and occupancy over a period of 11 years, combined with postreintroduction genetic sampling, revealed survival and recruitment of reintroduced fish. Genomic analyses based on data from the original wild rescued, captive born, and reintroduced cohorts revealed low inbreeding and strong maintenance of neutral and candidate adaptive genomic diversity across multiple generations. An increasing trend in the effective population size of the reintroduced population was consistent with field monitoring data in demonstrating successful re-establishment of the species. This provides a rare empirical example that the adaptive potential of a locally extinct population can be maintained during genetically informed ex-situ conservation breeding and reintroduction into the wild. Strategies to improve biodiversity restoration via ex-situ conservation should include genetic-based captive breeding and longitudinal monitoring of standing genomic variation in reintroduced populations.

Monitoreo Longitudinal de la Diversidad Genómica Neutral y Adaptativa en una Reintroducción Marshall et al. 21-643 Resumen Los programas de restauración a manera de reproducción ex situ combinada con reintroducciones se están volviendo críticos para contrarrestar las declinaciones demográficas y la pérdida de especies. Dichos programas usan cada vez más la gestión genética para mejorar los resultados de conservación. Sin embargo, la falta de monitoreo a largo plazo de los indicadores genéticos posteriores a la reintroducción evita que se realicen evaluaciones de la trayectoria y la persistencia de las poblaciones reintroducidas. Se rescató un pez de talla pequeña (percha pigmea del sur [Nannoperca australis]) previo a su extirpación de los lagos terminales de la Cuenca Murray-Darling en Australia para después reproducirlo en cautiverio con información genética y reintroducirlo. Realizamos monitoreos anuales o bianuales de la abundancia, aptitud y ocupación en vida silvestre durante once años, además de un muestreo genético posterior a la reintroducción. Analizamos los datos genómicos de los grupos originales rescatados, los nacidos en cautiverio y los reintroducidos. Nuestro objetivo era evaluar los efectos genómicos a largo plazo de la reproducción en cautiverio y la reintroducción de esta especie. Esto reveló baja endogamia y el sólido mantenimiento de la diversidad genómica neutral y adaptativa durante varias generaciones. Encontramos una coherencia entre la tendencia creciente en el tamaño de la población efectiva de la población reintroducida y los datos de campo que demostraron el restablecimiento exitoso de la especie. Nuestro estudio proporciona un raro ejemplo empírico de cómo el potencial adaptativo de una población localmente extinta puede mantenerse durante la reproducción de conservación ex situ genéticamente informada y su reintroducción. Las estrategias para mejorar la restauración de la biodiversidad por medio de la conservación ex situ deberían incluir la reproducción en cautiverio basada en la genética y el monitoreo longitudinal de la variación genómica actual de las poblaciones reintroducidas.

Near infra-red fluorescence identification of the thoracic duct to prevent chyle leaks during oesophagectomy.

BACKGROUND: Chyle leaks following oesophagectomy are a frustrating complication of surgery with considerable morbidity. The use of near infra-red (NIR) fluorescence in surgery is an emerging technology and the use of fluorescence to identify the thoracic duct has been demonstrated in animal work and early human case reports. This study evaluated the use mesenteric and enteral administration of indocyanine green (ICG) in humans to identify the thoracic duct during oesophagectomy. METHODS: Patients undergoing oesophagectomy were recruited to the study. Administration of ICG via an enteral route or mesenteric injection was evaluated. Fluorescence was assessed using a NIR fluorescence enabled laparoscope system with a visual scoring system and signal to background ratios. Visualisation of the thoracic duct under white light and NIR fluorescence was compared as well as any identification of active chyle leak. Patients were followed up post-operatively for adverse events and chyle leak. RESULTS: 20 patients received ICG and were included in the study. The enteral route failed to fluoresce the thoracic duct. Mesenteric injection (17 patients) identified the thoracic duct under fluorescence prior to white light in 70% of patients with a mean signal to background ratio of 5.35. In 6 participants, a possible active chyle leak was identified under fluorescence with 4 showing active chyle leak from what was identified as the thoracic duct. CONCLUSION: This study demonstrates that ICG administration via mesenteric injection can highlight the thoracic duct during oesophagectomy and may be a potential technology to reduce chyle leak following surgery. CLINICAL TRIAL REGISTRATION: Clinical trials.gov (NCT03292757).

Analysis of 52 240 source plasma donors of convalescent COVID-19 plasma: Sex, ethnicity, and age association with initial antibody levels and rate of dissipation.

BACKGROUND: COVID-19 convalescent plasma (CCP) was approved under emergency authorization to treat critically ill patients with COVID-19 in the United States in 2020. We explored the demographics of donors contributing plasma for a hyperimmune, plasma-derived therapy to evaluate factors that may be associated with anti-SARS-CoV-2 antibody response variability and, subsequently, antibody titers. STUDY DESIGN: An electronic search of CCP donors was performed across 282 US plasma donation centers. Donations were screened for nucleocapsid protein-binding-IgG using the Abbott SARS-CoV-2 IgG assay. RESULTS: Overall, 52 240 donors donated 418 046 units of CCP. Donors were of various ethnicities: 43% Caucasian, 34% Hispanic, 17% African American, 2% Native American, 1% Asian, and 3% other. Females had higher initial mean anti-SARS-CoV-2 antibody titers but an overall faster rate of decline (P < .0001). Initial antibody titers increased with age: individuals aged 55 to 66 years had elevated anti-SARS-CoV-2 titers for longer periods compared with other ages (P = .0004). African American donors had the lowest initial antibody titers but a slower rate of decline (P < .0001), while Caucasian (P = .0088) and Hispanic (P = .0193) groups had the fastest rates of decline. Most donor antibody levels decreased below the inclusion criteria (≥1.50) within 30 to 100 days of first donation, but donation frequency did not appear to be associated with rate of decline. CONCLUSION: Several factors may be associated with anti-SARS-CoV-2 antibody response including donor age and sex. Evaluating these factors during development of future hyperimmune globulin products may help generation of therapies with optimal efficacy.

Determination of neutralising anti-SARS-CoV-2 antibody half-life in COVID-19 convalescent donors.

Despite the burgeoning field of coronavirus disease-19 (COVID-19) research, the persistence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralising antibodies remains unclear. This study validated two high-throughput immunological methods for use as surrogate live virus neutralisation assays and employed them to examine the half-life of SARS-CoV-2 neutralising antibodies in convalescent plasma donations made by 42 repeat donors between April and September 2020. SARS-CoV-2 neutralising antibody titres decreased over time but typically remained above the methods' diagnostic cut-offs. Using this longitudinal data, the average half-life of SARS-CoV-2 neutralising antibodies was determined to be 20.4 days. SARS-CoV-2 neutralising antibody titres appear to persist in the majority of donors for several months. Whether these titres confer protection against re-infection requires further study and is of particular relevance as COVID-19 vaccines become widely available.

Deconstructing depression and negative symptoms of schizophrenia; differential and longitudinal immune correlates, and response to minocycline treatment.

BACKGROUND: Immune dysfunction has been implicated in negative symptoms of schizophrenia and also in depression. These disorders are frequently co-morbid, with some symptoms such as anhedonia and apathy common to both. The anti-inflammatory agent minocycline may be ineffective in schizophrenia, but more positive effects have been seen in depression. Our aim was to investigate the role of immune dysfunction in depression and sub-domains of negative symptoms in schizophrenia by investigating their intercorrelation and the influence of treatment with minocycline. METHODS: We analysed longitudinal data from 207 patients within 5 years of onset of schizophrenia, from the randomised double-blind, placebo-controlled trial of minocycline (BeneMin). Symptom ratings and circulating IL-6, C-reactive protein (CRP) and TNF-α concentrations were collected at baseline and repeated over twelve months. The sample was not stratified by CRP prior to randomisation. Positive and Negative Syndrome Scale composite ratings of avolition-apathy and diminished expression, Calgary Depression Scale total scores, and immune markers were examined cross-sectionally using Spearman's rank, and longitudinally by linear mixed effect models that included body mass index and minocycline. Additionally, post hoc analysis of the sample stratified by elevated CRP (>1 mg/l and <10 mg/l at baseline) was carried out to assess whether minocycline had any effect on specific symptoms in an immune active sub-group of patients. RESULTS: Depression and avolition-apathy were significantly positively related, and depression correlated weakly with IL-6 at baseline. Diminished expression was associated with increased TNF-α both cross-sectionally and longitudinally. CRP was unrelated to any symptom domain. Minocycline did not affect any individual symptom or sub-domain in the full sample or in the immune active sub-group. DISCUSSION: IL-6 may have some specificity to depression in early schizophrenia. TNF-α may be an indicator of immune dysfunction relevant to negative symptoms, and our longitudinal findings add to this evidence. However, minocycline continues to show very little promise as a treatment for any symptom dimension of early schizophrenia.

Treatment Recommendations for Tardive Dyskinesia.

BACKGROUND: Tardive dyskinesia is a movement disorder characterised by irregular, stereotyped, and choreiform movements associated with the use of antipsychotic medication. We aim to provide recommendations on the treatment of tardive dyskinesia. METHODS: We performed a systematic review of studies of the treatment of tardive dyskinesia. Studies were rated for methodological quality using the American Academy of Neurology Risk of Bias Classification system. Overall level of evidence classifications and grades of recommendation were made using the Scottish Intercollegiate Guidelines Network framework. RESULTS: Preventing tardive dyskinesia is of primary importance, and clinicians should follow best practice for prescribing antipsychotic medication, including limiting the prescription for specific indications, using the minimum effective dose, and minimising the duration of therapy. The first-line management of tardive dyskinesia is the withdrawal of antipsychotic medication if clinically feasible. Yet, for many patients with serious mental illness, the discontinuation of antipsychotics is not possible due to disease relapse. Switching from a first-generation to a second-generation antipsychotic with a lower D2 affinity, such as clozapine or quetiapine, may be effective in reducing tardive dyskinesia symptoms. The strongest evidence for a suitable co-intervention to treat tardive dyskinesia comes from tests with the new VMAT inhibitors, deutetrabenazine and valbenazine. These medications have not been approved for use in Canada. CONCLUSION: Data on tardive dyskinesia treatment are limited, and the best management strategy remains prevention. More long-term safety and efficacy data are needed for deutetrabenazine and valbenazine, and their routine availability to patients outside of the USA remains in question.

Methylene blue fluorescence of the ureter during colorectal surgery.

BACKGROUND: Iatrogenic ureteric injury is a serious complication of colorectal surgery. Incidence is estimated to be between 0.3 and 1.5%. Of all ureteric injuries, 9% occur during colorectal procedures. Ureteric stents are utilised as a method to reduce the risk of injury; however, these are not without risk and do not guarantee prevention of injury. Fluorescence is a safe and effective alternative for intraoperative ureteric localisation. This proof of principle study aims to assess the use of methylene blue to fluoresce the ureter during colorectal surgery. METHOD: Patients undergoing elective colorectal surgery were included in this open label, non-randomised study. Methylene blue was administered intravenously at varying doses (0.25-1 mg/kg) over 5 min, 10-15 min prior to entering 'ureteric territory.' Fluorescence was assessed using the PINPOINT Deep Red laparoscopic system at fixed time points by the surgeon and an independent observer. RESULTS: 42 patients received methylene blue; 2 patients were excluded from analysis. Of the 69 ureters assessed, 64 were seen under fluorescence. Of these, 14 were not visible under white light. 50 ureters were observed with both fluorescence and white light with 14 of these being seen earlier with fluorescence. In ten cases, fluorescence revealed the ureter to be in a different location than suspected. CONCLUSION: Fluorescence is a promising method to allow visualisation of the ureter, where it is not identified easily under standard operative conditions, thereby improving safety and reducing operative time and difficulty.

Movement Disorders Associated With Antipsychotic Medication in People With Schizophrenia: An Overview of Cochrane Reviews and Meta-Analysis.

Movement disorders associated with antipsychotic medications are relatively common, stigmatising, and potentially disabling. Their prevalence in people with psychosis who are prescribed second-generation antipsychotics (SGAs) is uncertain, as is their level of recognition by clinicinas. We conducted meta-analyses of randomised controlled trials included in the Cochrane Database of Systematic Reviews on schizophrenia and schizophrenia-like psychoses to estimate the prevalence of new-onset dystonia, akathisia, parkinsonism, and tremor with SGAs (amisulpride, asenapine, aripiprazole, clozapine, olanzapine, paliperidone, quetiapine, risperidone, L-sulpiride, and ziprasidone) approved in Canada and the UK, comparing them with haloperidol and chlorpromazine. We used a random effects model because of the heterogeneity between-studies in drug dosage and method of ascertainment of movement disorders. Our systematic search yielded 37 Cochrane systematic reviews (28 for SGAs), which generated 316 informative randomised controlled trials (243 for SGAs). With respect to SGAs, prevalence estimates ranged from 1.4% (quetiapine) to 15.3% (L-sulpiride) for dystonia, 3.3% (paliperidone) to 16.4% (L-sulpiride) for akathisia, 2.4% (asenapine) to 29.3% (L-sulpiride) for parkinsonism, and 0.2% (clozapine) to 28.2% (L-sulpiride) for tremor. Prevalence estimates were not influenced by treatment duration, the use of a flexible or fixed dosing scheme, or whether studies used validated instruments for the screening/rating of movement disorders. Overall, we found high overlap on the prevalence of new-onset movement disorders across different SGAs precribed for established psychoses. Variations in prevalence figures across antipsychotic medications were observed for the different movement disorders. Differences in pharmacological properties, such as for the dopamine D2 R association rate and serotonin 5-HT2A antagonism, could contribute to this variation.

The Assessment and Treatment of Antipsychotic-Induced Akathisia.

BACKGROUND: Akathisia is a common and distressing neuropsychiatric syndrome associated with antipsychotic medication, characterised by subjective and objective psychomotor restlessness. The goal of this guideline is to provide clinicians with recommendations on the assessment and treatment of akathisia. METHODS: We performed a systematic review of therapeutic studies assessing the treatment of antipsychotic-induced extrapyramidal symptoms. Forty studies on akathisia and 4 systematic reviews evaluating the adverse effects of antipsychotics were used in the formulation of recommendations. Studies were rated for methodological quality using the American Academy of Neurology Risk of Bias Classification system. The overall level of evidence classifications and grades of recommendation were made using the Scottish Intercollegiate Guidelines Network framework. RESULTS: As a good practice point, clinicians should systematically assess akathisia with a validated scale before starting antipsychotics and during antipsychotic dosage titration. For the management of akathisia, there was adequate evidence to allow recommendations regarding antipsychotic dose reduction, antipsychotic polypharmacy, switching antipsychotic medication, and the use of adjuvant medications including beta-blockers, anticholinergics, 5HT2A antagonists, benzodiazepines, and vitamin B6. CONCLUSION: The treatment of antipsychotic-induced akathisia should be personalised, with consideration of antipsychotic dose reduction, cessation of antipsychotic polypharmacy, and switching to an antipsychotic with a perceived lower liability for akathisia, before the use of adjuvant medications. The choice of adjuvant medications should favour the more established treatments, with careful consideration of contraindications and side effects. Limitations in the evidence should be acknowledged and prompt cautious prescribing, particularly with respect to the duration of use of adjuvant medications, is warranted.

Integrative Music Therapy: A Healing Intervention.

Music plays a significant role in the lives of individuals across the lifespan. Some healthcare providers may not appreciate music therapy and the positive benefits it can have on the environment, patients, caregivers, and healthcare staff. Integrative Music Therapy (IMT) has proven to be effective in multiple settings, offering therapy for behavioral, emotional, physiological, psychological, and psychosocial needs. IMT, performed by a trained, certified professional (MT-BC), does not seek to replace medication or other procedures, but works synergistically with provided healthcare.

Design and protocol for the Focusing on Clozapine Unresponsive Symptoms (FOCUS) trial: a randomised controlled trial.

BACKGROUND: For around a third of people with a diagnosis of schizophrenia, the condition proves to respond poorly to treatment with many typical and atypical antipsychotics. This is commonly referred to as treatment-resistant schizophrenia. Clozapine is the only antipsychotic with convincing efficacy for people whose symptoms are considered treatment-resistant to antipsychotic medication. However, 30-40 % of such conditions will have an insufficient response to the drug. Cognitive behavioural therapy has been shown to be an effective treatment for schizophrenia when delivered in combination with antipsychotic medication, with several meta-analyses showing robust support for this approach. However, the evidence for the effectiveness of cognitive behavioural therapy for people with a schizophrenia diagnosis whose symptoms are treatment-resistant to antipsychotic medication is limited. There is a clinical and economic need to evaluate treatments to improve outcomes for people with such conditions. METHODS/DESIGN: A parallel group, prospective randomised, open, blinded evaluation of outcomes design will be used to compare a standardised cognitive behavioural therapy intervention added to treatment as usual versus treatment as usual alone (the comparator group) for individuals with a diagnosis of schizophrenia for whom an adequate trial of clozapine has either not been possible due to tolerability problems or was not associated with a sufficient therapeutic response. The trial will be conducted across five sites in the United Kingdom. DISCUSSION: The recruitment target of 485 was achieved, with a final recruitment total of 487. This trial is the largest definitive, pragmatic clinical and cost-effectiveness trial of cognitive behavioural therapy for people with schizophrenia whose symptoms have failed to show an adequate response to clozapine treatment. Using a prognostic risk model, baseline information will be used to explore whether there are identifiable subgroups for which the treatment effect is greatest. TRIAL REGISTRATION: Current Controlled Trials ISRCTN99672552 . Registered 29(th) November 2012.

Design of a superior cytokine antagonist for topical ophthalmic use.

IL-1 is a key inflammatory and immune mediator in many diseases, including dry-eye disease, and its inhibition is clinically efficacious in rheumatoid arthritis and cryopyrin-associated periodic syndromes. To treat ocular surface disease with a topical biotherapeutic, the uniqueness of the site necessitates consideration of the agent's size, target location, binding kinetics, and thermal stability. Here we chimerized two IL-1 receptor ligands, IL-1ß and IL-1Ra, to create an optimized receptor antagonist, EBI-005, for topical ocular administration. EBI-005 binds its target, IL-1R1, 85-fold more tightly than IL-1Ra, and this increase translates to an ∼100-fold increase in potency in vivo. EBI-005 preserves the affinity bias of IL-1Ra for IL-1R1 over the decoy receptor (IL-1R2), and, surprisingly, is also more thermally stable than either parental molecule. This rationally designed antagonist represents a unique approach to therapeutic design that can potentially be exploited for other ß-trefoil family proteins in the IL-1 and FGF families.

Fissurectomy Combined with High-Dose Botulinum Toxin Is a Safe and Effective Treatment for Chronic Anal Fissure and a Promising Alternative to Surgical Sphincterotomy.

BACKGROUND: There is paucity of data on the long-term outcome of the combination of fissurectomy and botulinum toxin A injection for the management of chronic anal fissure. OBJECTIVES: The aim of this study is to assess the safety, efficacy, and long-term outcome of the combination of fissurectomy and botulinum toxin A injection. DESIGN: This is a nonrandomized prospective cohort study. SETTINGS: This study was conducted at a district general hospital in the United Kingdom. PATIENTS: The cohort included all patients treated with fissurectomy and botulinum toxin A for chronic anal fissure between September 2008 and March 2012. INTERVENTION: The patients were treated with a combination of fissurectomy and botulinum toxin A injection. MAIN OUTCOME MEASURES: Symptomatic relief, fissure healing, complications, recurrence, and the need for further surgical intervention. RESULTS: One hundred and two patients received fissurectomy and botulinum toxin A injection for chronic anal fissure. At 12-week follow-up, 68 patients had resolution of symptoms and complete healing of chronic anal fissure, 29 patients had improvement of symptoms but incomplete healing and had further topical or botulinum toxin A treatment with subsequent complete healing. Ninety-five patients (93%) reported no postoperative complications. Seven patients reported a degree of incontinence in the immediate postoperative period. All reported normal continence at12-week follow-up. No local complications were observed or reported. At the mean follow-up of 33 months, there was no evidence of recurrence. Twelve-month follow-up was conducted via telephone interview only. LIMITATIONS: This study is nonrandomized and did not examine the dose response of Botulinum Toxin A. CONCLUSIONS: Fissurectomy combined with high-dose botulinum toxin A is a safe, effective, and durable option for the management of chronic anal fissure and a promising alternative to surgical sphincterotomy.

Detection of cadherin-17 in human colon cancer LIM1215 cell secretome and tumour xenograft-derived interstitial fluid and plasma.

Colorectal cancer (CRC), one of the most prevalent cancers in the western world, is treatable if detected early. However, 70% of CRC is detected at an advanced stage. This is largely due to the inadequacy of current faecal occult blood screening testing and costs involved in conducting population-based colonoscopy, the 'gold standard' for CRC detection. Another biomarker for CRC, carcinoembryonic antigen, while useful for monitoring CRC recurrence, is ineffective, lacking the specificity required early detection of CRC. For these reasons there is a need for more effective blood-based markers for early CRC detection. In this study we targeted glycoproteins secreted from the human colon carcinoma cell line LIM1215 as a source of potential CRC biomarkers. Secreted candidate glycoproteins were confirmed by MS and validated by Western blot analysis of tissue/tumour interstitial fluid (Tif) from LIM1215 xenograft tumours grown in immunocompromised mice. Overall, 39 glycoproteins were identified in LIM1215 culture media (CCM) and 5 glycoproteins in LIM1215 tumour xenograft Tif; of these, cadherin-17 (CDH17), galectin-3 binding protein (LGALS3BP), and tyrosine-protein kinase-like 7 (PTK7) were identified in both CM and glycosylation motifs. Swiss-Prot was used to annotate Tif. Many of the glycoproteins identified in this study (e.g., AREG, DSG2, EFNA1, EFNA3, EFNA4, EPHB4, ST14, and TIMP1) have been reported to be implicated in CRC biology. Interestingly, the cadherin-17 ectodomain, but not full length cadherin-17, was identified in CM, Tif and plasma derived from mice bearing the LIM1215 xenograft tumour. To our knowledge, this is the first report of the cadherin-17 ectodomain in plasma. In this study, we report for the first time that the presence of full-length cadherin-17 in exosomes released into the CM. This article is part of a Special Issue entitled: An Updated Secretome.

Proteome profiling of exosomes derived from human primary and metastatic colorectal cancer cells reveal differential expression of key metastatic factors and signal transduction components.

Exosomes are small extracellular 40-100 nm diameter membrane vesicles of late endosomal origin that can mediate intercellular transfer of RNAs and proteins to assist premetastatic niche formation. Using primary (SW480) and metastatic (SW620) human isogenic colorectal cancer cell lines we compared exosome protein profiles to yield valuable insights into metastatic factors and signaling molecules fundamental to tumor progression. Exosomes purified using OptiPrep™ density gradient fractionation were 40-100 nm in diameter, were of a buoyant density ~1.09 g/mL, and displayed stereotypic exosomal markers TSG101, Alix, and CD63. A major finding was the selective enrichment of metastatic factors (MET, S100A8, S100A9, TNC), signal transduction molecules (EFNB2, JAG1, SRC, TNIK), and lipid raft and lipid raft-associated components (CAV1, FLOT1, FLOT2, PROM1) in exosomes derived from metastatic SW620 cells. Additionally, using cryo-electron microscopy, ultrastructural components in exosomes were identified. A key finding of this study was the detection and colocalization of protein complexes EPCAM-CLDN7 and TNIK-RAP2A in colorectal cancer cell exosomes. The selective enrichment of metastatic factors and signaling pathway components in metastatic colon cancer cell-derived exosomes contributes to our understanding of the cross-talk between tumor and stromal cells in the tumor microenvironment.