Evaluation of ATOX1 as a Potential Predictive Biomarker for Tetrathiomolybdate Treatment of Breast Cancer Patients with High Risk of Recurrence

Copper plays a key role in cancer metastasis, which is the most common cause of cancer death. Copper depletion treatment with tetrathiomolybdate (TM) improved disease-free survival in breast cancer patients with high risk of recurrence in a phase II clinical trial. Because the copper metallochaperone ATOX1 was recently reported to drive breast cancer cell migration and breast cancer migration is a critical factor in metastasis, we tested if ATOX1 expression levels in primary tumor tissue could predict the TM treatment outcome of breast cancer patients at high risk of recurrence. We performed ATOX1 immunohistochemical staining of breast tumor material (before TM treatment) of 47 patients enrolled in the phase II TM clinical trial and evaluated ATOX1 expression levels in relation with patient outcome after TM treatment. Our results show that higher ATOX1 levels in the tumor cell cytoplasm correlate with a trend towards better event-free survival after TM treatment for triple-negative breast cancer patients and patients at stage III of disease. In conclusion, ATOX1 may be a potential predictive biomarker for TM treatment of breast cancer patients at high risk of recurrence and should be tested in a larger cohort of patients

Loss of CHGA Protein as a Potential Biomarker for Colon Cancer Diagnosis: A Study on Biomarker Discovery by Machine Learning and Confirmation by Immunohistochemistry in Colorectal Cancer Tissue Microarrays

Background. The incidence of colorectal cancers has been constantly increasing. Although the mortality has slightly decreased, it is far from satisfaction. Precise early diagnosis for colorectal cancer has been a great challenge in order to improve patient survival. Patients and Methods. We started with searching for protein biomarkers based on our colorectal cancer biomarker database (CBD), finding differential expressed genes (GEGs) and non-DEGs from RNA sequencing (RNA-seq) data, and further predicted new biomarkers of protein–protein interaction (PPI) networks by machine learning (ML) methods. The best-selected biomarker was further verified by a receiver operating characteristic (ROC) test from microarray and RNA-seq data, biological network, and functional analysis, and immunohistochemistry in the tissue arrays from 198 specimens. Results. There were twelve proteins (MYO5A, CHGA, MAPK13, VDAC1, CCNA2, YWHAZ, CDK5, GNB3, CAMK2G, MAPK10, SDC2, and ADCY5) which were predicted by ML as colon cancer candidate diagnosis biomarkers. These predicted biomarkers showed close relationships with reported biomarkers of the PPI network and shared some pathways. An ROC test showed the CHGA protein with the best diagnostic accuracy (AUC = 0.9 in microarray data and 0.995 in RNA-seq data) among these candidate protein biomarkers. Furthermore, immunohistochemistry examination on our colon cancer tissue microarray samples further confirmed our bioinformatical prediction, indicating that CHGA may be used as a potential biomarker for early diagnosis of colon cancer patients. Conclusions. CHGA could be a potential candidate biomarker for diagnosing earlier colon cancer in the patients

Defining the human copper proteome and analysis of its expression variation in cancers.

Copper (Cu) is essential for living organisms, and acts as a cofactor in many metabolic enzymes. To avoid the toxicity of free Cu, organisms have specific transport systems that 'chaperone' the metal to targets. Cancer progression is associated with increased cellular Cu concentrations, whereby proliferative immortality, angiogenesis and metastasis are cancer hallmarks with defined requirements for Cu. The aim of this study is to gather all known Cu-binding proteins and reveal their putative involvement in cancers using the available database resources of RNA transcript levels. Using the database along with manual curation, we identified a total of 54 Cu-binding proteins (named the human Cu proteome). Next, we retrieved RNA expression levels in cancer versus normal tissues from the TCGA database for the human Cu proteome in 18 cancer types, and noted an intricate pattern of up- and downregulation of the genes in different cancers. Hierarchical clustering in combination with bioinformatics and functional genomics analyses allowed for the prediction of cancer-related Cu-binding proteins; these were specifically inspected for the breast cancer data. Finally, for the Cu chaperone ATOX1, which is the only Cu-binding protein proposed to have transcription factor activities, we validated its predicted over-expression in patient breast cancer tissue at the protein level. This collection of Cu-binding proteins, with RNA expression patterns in different cancers, will serve as an excellent resource for mechanistic-molecular studies of Cu-dependent processes in cancer.Funding agencies: Swedish Society for Medical Research; Folke and Marianne Edler Research Fund; Lars Hierta Memorial Foundation; Knut and Alice Wallenberg Foundation; Swedish Research Council; Chalmers Foundation; NBIS (National Bioinformatics Infrastructure Sweden)</p

Near-Infrared Emitting and Pro-Angiogenic Electrospun Conjugated Polymer Scaffold for Optical Biomaterial Tracking

Noninvasive tracking of biomaterials is vital for determining the fate and degradation of an implant in vivo, and to show its role in tissue regeneration. Current biomaterials have no inherent capacity to enable tracing but require labeling with, for example, fluorescent dyes, or nanoparticles. Here a novel biocompatible fully conjugated electrospun scaffold is described, based on a semiconducting luminescent polymer that can be visualized in situ after implantation using fluorescence imaging. The polymer, poly [2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt -thiophene-2,5-diyl] (TQ1), is electrospun to form a fibrous mat. The fibers display fluorescence emission in the near-infrared region with lifetimes in the sub-nanosecond range, optimal for in situ imaging. The material shows no cytotoxic behaviors for embryonic chicken cardiomyocytes and mouse myoblasts, and cells migrate onto the TQ1 fibers even in the presence of a collagen substrate. Subcutaneous implantations of the material in rats show incorporation of the TQ1 fibers within the tissue, with limited inflammation and a preponderance of small capillaries around the fibers. The fluorescent properties of the TQ1 fibers are fully retained for up to 90 d following implantation and they can be clearly visualized in tissue using fluorescence and lifetime imaging, thus making it both a pro-angiogenic and traceable biomaterial.Funding Agencies|Linkoping University; Swedish Foundation for Strategic Research; Swedish Research Council</p

Intussusceptive Vascular Remodeling Precedes Pathological Neovascularization

Objective— Pathological neovascularization is crucial for progression and morbidity of serious diseases such as cancer, diabetic retinopathy, and age-related macular degeneration. While mechanisms of ongoing pathological neovascularization have been extensively studied, the initiating pathological vascular remodeling (PVR) events, which precede neovascularization remains poorly understood. Here, we identify novel molecular and cellular mechanisms of preneovascular PVR, by using the adult choriocapillaris as a model. Approach and Results— Using hypoxia or forced overexpression of VEGF (vascular endothelial growth factor) in the subretinal space to induce PVR in zebrafish and rats respectively, and by analyzing choriocapillaris membranes adjacent to choroidal neovascular lesions from age-related macular degeneration patients, we show that the choriocapillaris undergo robust induction of vascular intussusception and permeability at preneovascular stages of PVR. This PVR response included endothelial cell proliferation, formation of endothelial luminal processes, extensive vesiculation and thickening of the endothelium, degradation of collagen fibers, and splitting of existing extravascular columns. RNA-sequencing established a role for endothelial tight junction disruption, cytoskeletal remodeling, vesicle- and cilium biogenesis in this process. Mechanistically, using genetic gain- and loss-of-function zebrafish models and analysis of primary human choriocapillaris endothelial cells, we determined that HIF (hypoxia-induced factor)-1α-VEGF-A-VEGFR2 signaling was important for hypoxia-induced PVR. Conclusions— Our findings reveal that PVR involving intussusception and splitting of extravascular columns, endothelial proliferation, vesiculation, fenestration, and thickening is induced before neovascularization, suggesting that identifying and targeting these processes may prevent development of advanced neovascular disease in the future. Visual Overview— An online visual overview is available for this article.Funding Agencies|Crown Princess Margareta Association for the Visually Impaired; Edwin Jordan Foundation; Swedish Eye Foundation; Svenska Sallskapet for Medicinsk Forskning; Linkoping Universitet; Eva och Oscar Ahrens Stiftelse; Ollie och Elof Ericssons Stiftelse; Carmen och Bertil Ragners Stiftelse; Gosta Fraenkels Stiftelse; Ake Wibergs Stiftelse; Lions Forskningsfond; Karin Sandbergs Stiftelse; Cancerfonden; Karolinska Institutets Stiftelser och Fonder; Vetenskapsradet</p