Multiplexed Quantum Dot Labeling of Activated c-Met Signaling in Castration-Resistant Human Prostate Cancer

The potential application of multiplexed quantum dot labeling (MQDL) for cancer detection and prognosis and monitoring therapeutic responses has attracted the interests of bioengineers, pathologists and cancer biologists. Many published studies claim that MQDL is effective for cancer biomarker detection and useful in cancer diagnosis and prognosis, these studies have not been standardized against quantitative biochemical and molecular determinations. In the present study, we used a molecularly characterized human prostate cancer cell model exhibiting activated c-Met signaling with epithelial to mesenchymal transition (EMT) and lethal metastatic progression to bone and soft tissues as the gold standard, and compared the c-Met cell signaling network in this model, in clinical human prostate cancer tissue specimens and in a castration-resistant human prostate cancer xenograft model. We observed c-Met signaling network activation, manifested by increased phosphorylated c-Met in all three. The downstream survival signaling network was mediated by NF-κB and Mcl-1 and EMT was driven by receptor activator of NF-κB ligand (RANKL), at the single cell level in clinical prostate cancer specimens and the xenograft model. Results were confirmed by real-time RT-PCR and western blots in a human prostate cancer cell model. MQDL is a powerful tool for assessing biomarker expression and it offers molecular insights into cancer progression at both the cell and tissue level with high degree of sensitivity

Development of a standardized histopathology scoring system for intervertebral disc degeneration in rat models: An initiative of the ORS spine section

International audienceBackground:Rats are a widely accepted preclinical model for evaluating inter-vertebral disc (IVD) degeneration and regeneration. IVD morphology is commonlyassessed using histology, which forms the foundation for quantifying the state of IVDdegeneration. IVD degeneration severity is evaluated using different grading systemsthat focus on distinct degenerative features. A standard grading system would facili-tate more accurate comparison across laboratories and more robust comparisons ofdifferent models and interventions.Aims:This study aimed to develop a histology grading system to quantify IVD degen-eration for different rat models. Materials & Methods:This study involved a literature review, a survey of experts inthe field, and a validation study using 25 slides that were scored by 15 graders fromdifferent international institutes to determine inter- and intra-rater reliability.Results:A new IVD degeneration grading system was established and it consists ofeight significant degenerative features, including nucleus pulposus (NP) shape, NParea, NP cell number, NP cell morphology, annulus fibrosus (AF) lamellar organization,AF tears/fissures/disruptions, NP-AF border appearance, as well as endplate disrup-tions/microfractures and osteophyte/ossification. The validation study indicated thissystem was easily adopted, and able to discern different severities of degenerativechanges from different rat IVD degeneration models with high reproducibility forboth experienced and inexperienced graders. In addition, a widely-accepted protocolfor histological preparation of rat IVD samples based on the survey findings includeparaffin embedding, sagittal orientation, section thickness < 10μm, and staining usingH&E and/or SO/FG to facilitate comparison across laboratories.Conclusion:The proposed histological preparation protocol and grading system pro-vide a platform for more precise comparisons and more robust evaluation of rat IVDdegeneration models and interventions across laboratories