Patients with class I V600EBRAF-mutant (MT) colorectal cancer exhibit a poor prognosis, and their response to combined anti-BRAF/EGFR inhibition remains limited. An unmet need exits for further understanding the biology of V600EBRAFMT colorectal cancer. We used differential gene expression of BRAFWT and MT colorectal cancer cells to identify pathways underpinning BRAFMT colorectal cancer.
View Article and Find Full Text PDFNovel covalent inhibitors of KRASG12C have shown limited response rates in patients with KRASG12C-mutant (MT) colorectal cancer. Thus, novel KRASG12C inhibitor combination strategies that can achieve deep and durable responses are needed. Small-molecule KRASG12C inhibitors AZ'1569 and AZ'8037 were used.
View Article and Find Full Text PDFExpression of the deubiquitinase USP17 is induced by multiple stimuli, including cytokines (IL-4/6), chemokines (IL-8, SDF1), and growth factors (EGF), and several studies indicate it is required for cell proliferation and migration. However, the mechanisms via which USP17 impacts upon these cellular functions are unclear. Here, we demonstrate that USP17 depletion prevents peripheral lysosome positioning, as well as trafficking of lysosomes to the cell periphery in response to EGF stimulation.
View Article and Find Full Text PDFCancer cells' ability to inhibit apoptosis is key to malignant transformation and limits response to therapy. Here, we performed multiplexed immunofluorescence analysis on tissue microarrays with 373 cores from 168 patients, segmentation of 2.4 million individual cells, and quantification of 18 cell lineage and apoptosis proteins.
View Article and Find Full Text PDFColorectal cancer (CRC) has one of the highest cancer incidences and mortality rates. In stage III, postoperative chemotherapy benefits <20% of patients, while more than 50% will develop distant metastases. Biomarkers for identification of patients at increased risk of disease recurrence following adjuvant chemotherapy are currently lacking.
View Article and Find Full Text PDFMotivation: Multiplexed immunofluorescence bioimaging of single-cells and their spatial organization in tissue holds great promise to the development of future precision diagnostics and therapeutics. Current multiplexing pipelines typically involve multiple rounds of immunofluorescence staining across multiple tissue slides. This introduces experimental batch effects that can hide underlying biological signal.
View Article and Find Full Text PDFEntosis is a form of nonphagocytic cell-in-cell (CIC) interaction where a living cell enters into another. Tumors show evidence of entosis; however, factors controlling entosis remain to be elucidated. Here, we find that besides inducing apoptosis, TRAIL signaling is a potent activator of entosis in colon cancer cells.
View Article and Find Full Text PDFThe present study shows the putative antiproliferative mechanism of action of the previously analytically characterized nudibranch extract ( NB) and its different effects in colon cancer cells vs. nontumor colon cells. NB extract increased the accumulation of reactive oxygen species (ROS) and increased endoplasmic reticulum (ER) stress via stimulation of the unfolded protein response.
View Article and Find Full Text PDFClinical trials for MET inhibitors have demonstrated limited success for their use in colon cancer (CC). However, clinical efficacy may be obscured by a lack of standardisation in MET assessment for patient stratification. In this study, we aimed to determine the molecular context in which MET is deregulated in CC using a series of genomic and proteomic tests to define MET expression and identify patient subgroups that should be considered in future studies with MET-targeted agents.
View Article and Find Full Text PDFResistance to chemotherapy-induced cell death is a major barrier to effective treatment of solid tumours such as colorectal cancer, CRC. Herein, we present a study aimed at developing a proteomics-based predictor of response to standard-of-care (SoC) chemotherapy in combination with antagonists of IAPs (inhibitors of apoptosis proteins), which have been implicated as mediators of drug resistance in CRC. We quantified the absolute expression of 19 key apoptotic proteins at baseline in a panel of 12 CRC cell lines representative of the genetic diversity seen in this disease to identify which proteins promote resistance or sensitivity to a model IAP antagonist [birinapant (Bir)] alone and in combination with SoC chemotherapy (5FU plus oxaliplatin).
View Article and Find Full Text PDFProstate cancer (PCa) is the most common non-cutaneous cancer in men and a notable cause of cancer mortality when it metastasises. The unfolded protein response (UPR) can be cytoprotective but when acutely activated can lead to cell death. In this study, we sought to enhance the acute activation of the UPR using radiation and ONC201, an UPR activator.
View Article and Find Full Text PDFRAS mutant (MT) metastatic colorectal cancer (mCRC) is resistant to MEK1/2 inhibition and remains a difficult-to-treat group. Therefore, there is an unmet need for novel treatment options for RASMT mCRC. RALA and RALB GTPases function downstream of RAS and have been found to be key regulators of several cell functions implicated in KRAS-driven tumorigenesis.
View Article and Find Full Text PDFBr J Cancer
November 2020
Background: Antibody-drug conjugate (ADC) construction poses numerous challenges that limit clinical progress. In particular, common bioconjugation methods afford minimal control over the site of drug coupling to antibodies. Here, such difficulties are overcome through re-bridging of the inter-chain disulfides of cetuximab (CTX) with auristatin-bearing pyridazinediones, to yield a highly refined anti-epidermal growth factor receptor (EGFR) ADC.
View Article and Find Full Text PDFThe phenotypic spectrum of colorectal cancer (CRC) is remarkably diverse, with seemingly endless variations in cell shape, mitotic figures and multicellular configurations. Despite this morphological complexity, histological grading of collective phenotype patterns provides robust prognostic stratification in CRC. Although mechanistic understanding is incomplete, previous studies have shown that the cortical protein ezrin controls diversification of cell shape, mitotic figure geometry and multicellular architecture, in 3D organotypic CRC cultures.
View Article and Find Full Text PDFThe anti-Epidermal Growth Factor Receptor (EGFR) antibody Cetuximab (CTX) has demonstrated limited anti-cancer efficacy in cells overexpressing EGFR due to activating mutations in RAS in solid tumours, such as pancreatic cancer. The utilisation of antibodies as targeting components of antibody-drug conjugates, such as trastuzumab emtansine (Kadcyla), demonstrates that antibodies may be repurposed to direct therapeutic agents to antibody-resistant cancers. Here we investigated the use of CTX as a targeting agent for camptothecin (CPT)-loaded polymeric nanoparticles (NPs) directed against KRAS mutant CTX-resistant cancer cells.
View Article and Find Full Text PDFPurpose: Dynamic network models predict clinical prognosis and inform therapeutic intervention by elucidating disease-driven aberrations at the systems level. However, the personalization of model predictions requires the profiling of multiple model inputs, which hampers clinical translation.
Patients And Methods: We applied APOPTO-CELL, a prognostic model of apoptosis signaling, to showcase the establishment of computational platforms that require a reduced set of inputs.
Background: The deubiquitinase USP17 is overexpressed in NSCLC and has been shown to be required for the growth and motility of EGFR wild-type (WT) NSCLC cells. USP17 is also required for clathrin-mediated endocytosis of EGFR. Here, we examine the impact of USP17 depletion on the growth, as well as EGFR endocytosis and signaling, of EGFR mutant (MT) NSCLC cells.
View Article and Find Full Text PDFmutations occur in ∼10% of colorectal cancer cases, are associated with poor survival, and have limited responses to BRAF/MEK inhibition with or without EGFR inhibition. There is an unmet need to understand the biology of poor prognostic MT colorectal cancer. We have used differential gene expression and pathway analyses of untreated stage II and stage III MT (discovery set: = 31; validation set: = 26) colorectal cancer, and an siRNA screen to characterize the biology underpinning the MT subgroup with poorest outcome.
View Article and Find Full Text PDFData from many preclinical studies, including those using cellular models of colorectal, gastric, gastro-oesophageal and gastro-oesophageal junction cancers, indicate that the hepatocyte growth factor (HGF)-hepatocyte growth factor receptor (c-MET) pathway is vital for the growth, survival and invasive potential of gastrointestinal cancers. Following the availability of data from these various studies, and data on c-MET expression as a biomarker that indicates a poor prognosis in patients with gastrointestinal cancer and increased c-MET expression, inhibitors targeting this pathway have entered the clinic in the past decade. However, the design of clinical trials that incorporate the use of HGF/c-MET inhibitors in their most appropriate genetic and molecular context remains crucial.
View Article and Find Full Text PDFIn recent times, our knowledge of the roles ubiquitin plays in multiple cellular processes has expanded exponentially, with one example being the role of ubiquitin in receptor endocytosis and trafficking. This has prompted a multitude of studies examining how the different machinery involved in the addition and removal of ubiquitin can influence this process. Multiple deubiquitylating enzymes (DUBs) have been implicated either in facilitating receptor endocytosis and lysosomal degradation or in rescuing receptor levels by preventing endocytosis and/or promoting recycling to the plasma membrane.
View Article and Find Full Text PDFc-MET and its ligand HGF are frequently overexpressed in colorectal cancer (CRC) and increased c-MET levels are found in CRC liver metastases. This study investigated the role of the HGF/c-MET axis in regulating migration/invasion in CRC, using pre-clinical models and clinical samples. Pre-clinically, we found marked upregulation of c-MET at both protein and mRNA levels in several invasive CRC cells.
View Article and Find Full Text PDFObjective: The mitochondrial apoptosis pathway is controlled by an interaction of multiple BCL-2 family proteins, and plays a key role in tumour progression and therapy responses. We assessed the prognostic potential of an experimentally validated, mathematical model of BCL-2 protein interactions (DR_MOMP) in patients with stage III colorectal cancer (CRC).
Design: Absolute protein levels of BCL-2 family proteins were determined in primary CRC tumours collected from n=128 resected and chemotherapy-treated patients with stage III CRC.
Apoptosis is essential for chemotherapy responses. In this discovery and validation study, we evaluated the suitability of a mathematical model of apoptosis execution (APOPTO-CELL) as a stand-alone signature and as a constituent of further refined prognostic stratification tools. Apoptosis competency of primary tumor samples from patients with stage III colorectal cancer ( = 120) was calculated by APOPTO-CELL from measured protein concentrations of Procaspase-3, Procaspase-9, SMAC, and XIAP.
View Article and Find Full Text PDFA recent phase II study of patients with metastatic colorectal carcinoma showed that mismatch repair gene status was predictive of clinical response to PD-1-targeting immune checkpoint blockade. Further examination revealed strong correlation between PD-L1 protein expression and microsatellite instability (MSI) in stage IV colorectal carcinoma, suggesting that the amount of PD-L1 protein expression could identify late-stage patients who might benefit from immunotherapy. To assess whether the clinical associations between PD-L1 gene expression and MSI identified in metastatic colorectal carcinoma are also present in stage II/III colorectal carcinoma, we used in silico analysis to elucidate the cell types expressing the PD-L1 gene.
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