Importance and Detection of Epithelial-to-Mesenchymal Transition (EMT) Phenotype in CTCs

The current dogma is that epithelial-to-mesenchymal transition (EMT) promotes circulating tumour cell (CTC) formation and is ultimately a driver of metastasis. There is also accumulating evidence that EMT-phenotype changes are commonly associated with therapy resistance. Thus, capturing EMT-phenotype CTCs is expected to yield important clinical information in regard to prognosis and response to therapy as well as allowing the study of metastatic processes. However, the isolation and identification of EMT-phenotype CTCs with commonly used isolation/detection methods are suboptimal, and current efforts on improving the isolation of EMT-phenotype CTCs are associated with pitfalls that need to be overcome. This chapter explores the significance of EMT in CTC formation and the role of EMT in cancer metastasis and resistance to therapy. We also comprehensively review the past and current limitations of evaluating EMT phenotypes in CTC isolation and analysis and discuss how CTCs can be seen in a more holistic fashion as important biomarkers for clinical management

The multiple potential biomarkers for predicting immunotherapy response : finding the needle in the haystack

Immune checkpoint inhibitors (ICIs) are being increasingly utilised in a variety of advanced malignancies. Despite promising outcomes in certain patients, the majority will not derive benefit and are at risk of potentially serious immune-related adverse events (irAEs). The development of predictive biomarkers is therefore critical to personalise treatments and improve outcomes. A number of biomarkers have shown promising results, including from tumour (programmed cell death ligand 1 (PD-L1), tumour mutational burden (TMB), stimulator of interferon genes (STING) and apoptosis-associated speck-like protein containing a CARD (ASC)), from blood (peripheral blood mononuclear cells (PBMCs), circulating tumour DNA (ctDNA), exosomes, cytokines and metal chelators) and finally the microbiome

Oncogenic B-RAFV600E Promotes Anchorage-Independent Survival of Human Melanocytes

4 page(s

Molecular biomarkers in glioblastoma : a systematic review and meta-analysis

BACKGROUND: Glioblastoma (GBM) is a highly aggressive cancer with poor prognosis that needs better treatment modalities. Moreover, there is a lack of reliable biomarkers to predict the response and outcome of current or newly designed therapies. While several molecular markers have been proposed as potential biomarkers for GBM, their uptake into clinical settings is slow and impeded by marker heterogeneity. Detailed assessment of prognostic and predictive value for biomarkers in well-defined clinical trial settings, if available, is scattered throughout the literature. Here we conducted a systematic review and meta-analysis to evaluate the prognostic and predictive significance of clinically relevant molecular biomarkers in GBM patients. MATERIAL AND METHODS: A comprehensive literature search was conducted to retrieve publications from 3 databases (Pubmed, Cochrane and Embase) from January 2010 to December 2021, using specific terms. The combined hazard ratios (HR) and confidence intervals (95% CI) were used to evaluate the association of biomarkers with overall survival (OS) in GBM patients. RESULTS: Twenty-six out of 1831 screened articles were included in this review. Nineteen articles were included in the meta-analyses, and 7 articles were quantitatively summarised. Fourteen studies with 1231 GBM patients showed a significant association of MGMT methylation with better OS with the pooled HR of 1.66 (95% CI 1.32-2.09, p < 0.0001, random effect). Five studies including 541 GBM patients analysed for the prognostic significance of IDH1 mutation showed significantly better OS in patients with IDH1 mutation with a pooled HR of 2.37 (95% CI 1.81-3.12; p < 0.00001]. Meta-analysis performed on 5 studies including 575 GBM patients presenting with either amplification or high expression of EGFR gene did not reveal any prognostic significance with a pooled HR of 1.31 (95% CI 0.96-1.79; p = 0.08). CONCLUSIONS: MGMT promoter methylation and IDH1 mutation are significantly associated with better OS in GBM patients. No significant associations were found between EGFR amplification or overexpression with OS

Prognostic and predictive value of liquid biopsy-derived androgen receptor variant 7 (AR-V7) in prostate cancer : a systematic review and meta-analysis

In advanced prostate cancer, access to recent diagnostic tissue samples is restricted and this affects the analysis of the association of evolving biomarkers such as AR-V7 with metastatic castrate resistance. Liquid biopsies are emerging as alternative analytes. To clarify clinical value of AR-V7 detection from liquid biopsies, here we performed a meta-analysis on the prognostic and predictive value of androgen receptor variant 7 (AR-V7) detected from liquid biopsy for patients with prostate cancer (PC), three databases, the Embase, Medline, and Scopus were searched up to September 2021. A total of 37 studies were included. The effects of liquid biopsy AR-V7 status on overall survival (OS), radiographic progression-free survival (PFS), and prostate-specific antigen (PSA)-PFS were calculated with RevMan 5.3 software. AR-V7 positivity detected in liquid biopsy significantly associates with worse OS, PFS, and PSA-PFS (P <0.00001). A subgroup analysis of patients treated with androgen receptor signaling inhibitors (ARSi such as abiraterone and enzalutamide) showed a significant association of AR-V7 positivity with poorer OS, PFS, and PSA-PFS. A statistically significant association with OS was also found in taxane-treated patients (P = 0.04), but not for PFS (P = 0.21) or PSA-PFS (P = 0.93). For AR-V7 positive patients, taxane treatment has better OS outcomes than ARSi (P = 0.01). Study quality, publication bias and sensitivity analysis were integrated in the assessment. Our data show that liquid biopsy AR-V7 is a clinically useful biomarker that is associated with poor outcomes of ARSi-treated castrate resistant PC (CRPC) patients and thus has the potential to guide patient management and also to stratify patients for clinical trials. More studies on chemotherapy-treated patients are warranted. Systematic Review Registration: PROSPERO, CRD42021239353

The prospect of identifying resistance mechanisms for castrate-resistant prostate cancer using circulating tumor cells : is epithelial-to-mesenchymal transition a key player?

Prostate cancer (PCa) is initially driven by excessive androgen receptor (AR) signaling with androgen deprivation therapy (ADT) being a major therapeutic approach to its treatment. However, the development of drug resistance is a significant limitation on the effectiveness of both first-line and more recently developed second-line ADTs. There is a need then to study AR signaling within the context of other oncogenic signaling pathways that likely mediate this resistance. This review focuses on interactions between AR signaling, the well-known phosphatidylinositol-3-kinase/AKT pathway, and an emerging mediator of these pathways, the Hippo/YAP1 axis in metastatic castrate-resistant PCa, and their involvement in the regulation of epithelial-mesenchymal transition (EMT), a feature of disease progression and ADT resistance. Analysis of these pathways in circulating tumor cells (CTCs) may provide an opportunity to evaluate their utility as biomarkers and address their importance in the development of resistance to current ADT with potential to guide future therapies

Vasoplegic Shock treated with Methylene Blue complicated by Severe Serotonin Syndrome.

Introduction: Management of severe vasoplegic shock in overdose can be very challenging. We describe a case of severe refractory vasodilatory shock in poisoning where methylene blue (MB) was used with success. Case Report. A 70kg 15-year-old male presented 1.5 hours post ingestion of a large polypharmacy overdose of quetiapine slow release 1.5g, quetiapine immediate release 12g, desvenlafaxine slow release 5.6g, venlafaxine 1050mg, amlodipine 290mg, ramipril 100mg, fluoxetine 560mg, promethazine 500mg and an unknown amount of lithium. He developed severe vasoplegic shock that was resistant to maximal doses of noradrenaline and vasopressin. MB was administered 6.5 hour post ingestion. Within 1 hour there was an improvement in his haemodynamic status and reduction of catecholamine requirements. Twelve hours post ingestion, he developed severe serotonin syndrome that lasted 5 days as a result of interaction between MB, a reversible monoamine oxidase inhibitor, and the antidepressants taken in overdose. MB had a calculated half-life of 38 hours. Conclusion MB is a useful second or third line strategy for severe drug induced vasodilatory shock, and may be potentially life-saving. Conversely, physicians should be aware that it can interact with other drugs and cause life-threatening serotonin syndrome. Lower doses or shorter durations may be wise in patients at risk of this interaction

Droplet digital PCR based androgen receptor variant 7 (AR-V7) detection from prostate cancer patient blood biopsies

Androgen receptor splice variant V7 (AR-V7) was recently identified as a valuable predictive biomarker in metastatic castrate-resistant prostate cancer. Here, we report a new, sensitive and accurate screen for AR-V7 mRNA expression directly from circulating tumor cells (CTCs): We combined EpCAM-based immunomagnetic CTC isolation using the IsoFlux microfluidic platform with droplet digital polymerase chain reaction (ddPCR) to analyze total AR and AR-V7 expression from prostate cancer patients CTCs. We demonstrate that AR-V7 is reliably detectable in enriched CTC samples with as little as five CTCs, even considering tumor heterogeneity, and confirm detection of AR-V7 in CTC samples from advanced prostate cancer (PCa) patients with AR-V7 detection limited to castrate resistant disease status in our sample set. Sensitive molecular analyses of circulating tumor cells (CTCs) or circulating tumor nucleic acids present exciting strategies to detect biomarkers, such as AR-V7 from non-invasive blood samples, so-called blood biopsies

Selective Loss of Wild-Type p16INK4a Expression in Human Nevi

4 page(s

Tumour immune microenvironment biomarkers predicting cytotoxic chemotherapy efficacy in colorectal cancer

The role of the local tumour and stromal immune landscape is increasingly recognised to be important in cancer development, progression and response to therapy. The composition, function, spatial orientation and gene expression profile of the infiltrate of the innate and adaptive immune system at the tumour and surrounding tissue has an established prognostic role in colorectal cancer (CRC). Multiple studies have confirmed that a tumour immune microenvironment (TIME) reflective of a type 1 adaptive immune response is associated with improved prognosis. There have been significant efforts to evolve these observations into validated, histopathology-based prognostic biomarkers, such as the Immunoscore. However, the clinical need lies much more in the development of predictive, not prognostic, biomarkers which have the potential to improve patient outcomes. This is particularly pertinent to help guide cytotoxic chemotherapy use in CRC, which remains the standard of care. Cytotoxic chemotherapy has recognised immunomodulatory activity distinct from its antimitotic effects, including mechanisms such as immunogenic cell death (ICD) and induction/inhibition of key immune players. Response to chemotherapy may differ with regard to molecular subtype of CRC, which are strongly associated with immune phenotypes. Thus, immune markers are potentially useful, though under-reported, predictive biomarkers. In this review, we discuss the impact of the TIME on response to cytotoxic chemotherapy in CRC, with a focus on baseline immune markers, and associated genomic and transcriptomic signatures