Potential Red-Flag Identification of Colorectal Adenomas with Wide-Field Fluorescence Molecular Endoscopy.

Adenoma miss rates in colonoscopy are unacceptably high, especially for sessile serrated adenomas / polyps (SSA/Ps) and in high-risk populations, such as patients with Lynch syndrome. Detection rates may be improved by fluorescence molecular endoscopy (FME), which allows morphological visualization of lesions with high-definition white-light imaging as well as fluorescence-guided identification of lesions with a specific molecular marker. In a clinical proof-of-principal study, we investigated FME for colorectal adenoma detection, using a fluorescently labelled antibody (bevacizumab-800CW) against vascular endothelial growth factor A (VEGFA), which is highly upregulated in colorectal adenomas. Methods: Patients with familial adenomatous polyposis (n = 17), received an intravenous injection with 4.5, 10 or 25 mg of bevacizumab-800CW. Three days later, they received NIR-FME. Results: VEGFA-targeted NIR-FME detected colorectal adenomas at all doses. Best results were achieved in the highest (25 mg) cohort, which even detected small adenomas (<3 mm). Spectroscopy analyses of freshly excised specimen demonstrated the highest adenoma-to-normal ratio of 1.84 for the 25 mg cohort, with a calculated median tracer concentration in adenomas of 6.43 nmol/mL. Ex vivo signal analyses demonstrated NIR fluorescence within the dysplastic areas of the adenomas. Conclusion: These results suggest that NIR-FME is clinically feasible as a real-time, red-flag technique for detection of colorectal adenomas.

Data-Driven Prioritization and Review of Targets for Molecular-Based Theranostic Approaches in Pancreatic Cancer.

Molecularly targeted therapeutic and imaging strategies directed at aberrant signaling pathways in pancreatic tumor cells may improve the poor outcome of pancreatic ductal adenocarcinoma (PDA). Therefore, relevant molecular targets need to be identified. Methods: We collected publicly available expression profiles of patient-derived normal pancreatic tissue (n = 77) and PDA samples (n = 103). Functional genomic messenger RNA profiling was applied to predict target upregulation on the protein level. We prioritized these targets based on current status of preclinical therapeutic and imaging evaluation in PDA. Results: We identified 213 significantly upregulated proteins in PDA compared with normal pancreatic tissue. We prioritized mucin-1, mesothelin, γ-glutamyltransferase 5, and cathepsin-E as the most interesting targets, because studies already demonstrated their potential for both therapeutic and imaging strategies in literature. Conclusion: This study can assist clinicians and drug developers in deciding which theranostic targets should be taken for further clinical evaluation in PDA.

Tyrosine kinase inhibitor induced growth factor receptor upregulation enhances the efficacy of near-infrared targeted photodynamic therapy in esophageal adenocarcinoma cell lines.

Esophageal carcinoma (EC) is a global health problem, with disappointing 5-year survival rates of only 15-25%. Near-infrared targeted photodynamic therapy (NIR-tPDT) is a novel strategy in which cancer-targeted phototoxicity is able to selectively treat malignant cells. In this in vitro report we demonstrate the applicability of antibody-based NIR-tPDT in esophageal adenocarcinoma (EAC), using the phototoxic compounds cetuximab-IRDye700DX and trastuzumab-IRDye700DX, targeting respectively epidermal growth factor receptor 1 (EGFR) and 2 (HER2). Furthermore, we demonstrate that NIR-tPDT can be made more effective by tyrosine kinase inhibitor (TKI) induced growth receptor upregulation. Together, these results unveil a novel strategy for non-invasive EAC treatment, and by pretreatment-induced receptor upregulation its future clinical application may be optimized.

Functional Genomic mRNA Profiling of Colorectal Adenomas: Identification and in vivo Validation of CD44 and Splice Variant CD44v6 as Molecular Imaging Targets.

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths worldwide. High adenoma miss rates, especially seen in high-risk patients, demand for better endoscopic detection. By fluorescently 'highlighting' specific molecular characteristics, endoscopic molecular imaging has great potential to fulfill this need. To implement this technique effectively, target proteins that distinguish adenomas from normal tissue must be identified. In this study we applied in silico Functional Genomic mRNA (FGmRNA) profiling, which is a recently developed method that results in an enhanced view on the downstream effects of genomic alterations occurring in adenomas on gene expression levels. FGmRNA profiles of sporadic adenomas were compared to normal colon tissue to identify overexpressed genes. We validated the protein expression of the top identified genes, AXIN2, CEMIP, CD44 and JUN, in sporadic adenoma patient samples via immunohistochemistry (IHC). CD44 was identified as the most attractive target protein for imaging purposes and we proved its relevance in high-risk patients by demonstrating CD44 protein overexpression in Lynch lesions. Subsequently, we show that the epithelial splice variant CD44V6 is highly overexpressed in our patient samples and we demonstrated the feasibility of visualizing adenomas in ApcMin/+ mice in vivo by using a fluorescently labeled CD44v6 targeting peptide. In conclusion, via in silico functional genomics and ex vivo protein validation, this study identified CD44 as an attractive molecular target for both sporadic and high-risk Lynch adenomas, and demonstrates the in vivo applicability of a small peptide drug directed against splice variant CD44v6 for adenoma imaging.

Molecular Fluorescence Endoscopy Targeting Vascular Endothelial Growth Factor A for Improved Colorectal Polyp Detection.

UNLABELLED: Small and flat adenomas are known to carry a high miss-rate during standard white-light endoscopy. Increased detection rate may be achieved by molecular fluorescence endoscopy with targeted near-infrared (NIR) fluorescent tracers. The aim of this study was to validate vascular endothelial growth factor A (VEGF-A) and epidermal growth factor receptor (EGFR)-targeted fluorescent tracers during ex vivo colonoscopy with an NIR endoscopy platform. METHODS: VEGF-A and EGFR expression was determined by immunohistochemistry on a large subset of human colorectal tissue samples--48 sessile serrated adenomas/polyps, 70 sporadic high-grade dysplastic adenomas, and 19 hyperplastic polyps--and tissue derived from patients with Lynch syndrome--78 low-grade dysplastic adenomas, 57 high-grade dysplastic adenomas, and 31 colon cancer samples. To perform an ex vivo colonoscopy procedure, 14 mice with small intraperitoneal EGFR-positive HCT116(luc) tumors received intravenous bevacizumab-800CW (anti-VEGF-A), cetuximab-800CW (anti-EGFR), control tracer IgG-800CW, or sodium chloride. Three days later, 8 resected HCT116(luc) tumors (2-5 mm) were stitched into 1 freshly resected human colon specimen and followed by an ex vivo molecular fluorescence colonoscopy procedure. RESULTS: Immunohistochemistry showed high VEGF-A expression in 79%-96% and high EGFR expression in 51%-69% of the colorectal lesions. Both targets were significantly overexpressed in the colorectal lesions, compared with the adjacent normal colon crypts. During ex vivo molecular fluorescence endoscopy, all tumors could clearly be delineated for both bevacizumab-800CW and cetuximab-800CW tracers. Specific tumor uptake was confirmed with fluorescent microscopy showing, respectively, stromal and cell membrane fluorescence. CONCLUSION: VEGF-A is a promising target for molecular fluorescence endoscopy because it showed a high protein expression, especially in sessile serrated adenomas/polyps and Lynch syndrome. We demonstrated the feasibility to visualize small tumors in real time during colonoscopy using a NIR fluorescence endoscopy platform, providing the endoscopist a wide-field red-flag technique for adenoma detection. Clinical studies are currently being performed in order to provide in-human evaluation of our approach.

A standardized light-emitting diode device for photoimmunotherapy.

UNLABELLED: Antibody-based photodynamic therapy-photoimmunotherapy (PIT)-is an ideal modality to improve cancer treatment because of its selective and tumor-specific mode of therapy. Because the use of PIT for cancer treatment is continuing to be described, there is great need to characterize a standardized light source for PIT application. In this work, we designed and manufactured a light-emitting diode (LED)/PIT device and validated the technical feasibility, applicability, safety, and consistency of the system for cancer treatment. METHODS: To outline the characteristics and photobiologic safety of the LED device, multiple optical measurements were performed in accordance with a photobiologic safety standard. A luciferase-transfected breast cancer cell line (2LMP-Luc) in combination with panitumumab-IRDye 700DX (pan-IR700) was used to validate the in vitro and in vivo performance of our LED device. RESULTS: Testing revealed the light source to be safe, easy to use, and independent of illumination and power output (mW cm(-2)) variations over time. For in vitro studies, an LED dose (2, 4, 6 J cm(-2))-dependent cytotoxicity was observed using propidium iodide exclusion and annexin V staining. Dose-dependent blebbing was also observed during microscopic analysis. Bioluminescence signals of tumors treated with 0.3 mg of pan-IR700 and 50 J cm(-2) decreased significantly (>80%) compared with signals of contralateral nontreated sites at 4 h and at 1 d after PIT. CONCLUSION: To our knowledge, a normalized and standardized LED device has not been explicitly described or developed. In this article, we introduce a standardized light source and validate its usability for PIT applications.

Towards clinically translatable NIR fluorescence molecular guidance for colonoscopy.

White-light surveillance colonoscopy is the standard of care for the detection and removal of premalignant lesions to prevent colorectal cancer, and the main screening recommendation following treatment for recurrence detection. However, it lacks sufficient diagnostic yield, exhibits unacceptable adenoma miss-rates and is not capable of revealing functional and morphological information of the detected lesions. Fluorescence molecular guidance in the near-infrared (NIR) is expected to have outstanding relevance regarding early lesion detection and heterogeneity characterization within and among lesions in these interventional procedures. Thereby, superficial and sub-surface tissue biomarkers can be optimally visualized due to a minimization of tissue attenuation and autofluorescence by comparison with the visible, which simultaneously enhance tissue penetration and assure minimal background. At present, this potential is challenged by the difficulty associated with the clinical propagation of disease-specific contrast agents and the absence of a commercially available endoscope that is capable of acquiring wide-field, NIR fluorescence at video-rates. We propose two alternative flexible endoscopic fluorescence imaging methods, each based on a CE certified commercial, clinical grade endoscope, and the employment of an approved monoclonal antibody labeled with a clinically applicable NIR fluorophore. Pre-clinical validation of these two strategies that aim at bridging NIR fluorescence molecular guidance to clinical translation is demonstrated in this study.

[A newborn with an acute itchy skin rash]. / Een meisje met een acute jeukende huiduitslag.

A 36-week-old girl presented with an itching papulous skin eruption symmetrically on her cheeks, buttocks and limbs. Based on the specific clinical presentation she was diagnosed with Gianotti-Crosti-syndrome. This is a self-limiting cutaneous response to a viral infection.