Correlation of Epidermal Growth Factor Receptor With Morphological Features of Colorectal Advanced Adenomas: A Pilot Correlative Case Series

Biodegradable fluorescent nanoparticles for endoscopic detection of colorectal carcinogenesis

Early and comprehensive endoscopic detection of colonic dysplasia - the most clinically significant precursor lesion to colorectal adenocarcinoma - provides an opportunity for timely, minimally-invasive intervention to prevent malignant transformation. Here, the development and evaluation of biodegradable near-infrared fluorescent silica nanoparticles (FSN) is described that have the potential to improve adenoma detection during fluorescence-assisted white-light colonoscopic surveillance in rodent and human-scale models of colorectal carcinogenesis. FSNs are biodegradable (t_1/2 of 2.7 weeks), well-tolerated, and enable detection and delineation of adenomas as small as 0.5 mm² with high tumor-to-background ratios. Furthermore, in the human-scale, APC ^1311/+ porcine model, the clinical feasibility and benefit of using FSN-guided detection of colorectal adenomas using video-rate fluorescence-assisted white-light endoscopy is demonstrated. Since nanoparticles of similar size (e.g., 100-150-nm) or composition (i.e., silica, silica/gold hybrid) have already been successfully translated to the clinic, and, clinical fluorescent/white light endoscopy systems are becoming more readily available, there is a viable path towards clinical translation of the proposed strategy for early colorectal cancer detection and prevention in high-risk patients.

The level of epidermal growth factor receptors expression is correlated with the advancement of colorectal adenoma: validation of a surface biomarker

INTRODUCTION

Data about the expression of Epidermal Growth Factor Receptors (EGFRs) in colorectal adenomas remain scarce.

RESULTS

101 patients were enrolled including 53 controls. All adenomas (n = 38) and CRC (n = 5) were EGFR positive. Hyperplastic polyps (HP) (n = 8) and control colons (n = 53) were EGFR negative in half of cases (p < 0.0001). A well significant gradient of increased EGFR expression was observed between adjacent mucosa, hyperplastic lesions, low grade dysplasia (LGD) (n = 30), high grade dysplasia (HGD) adenomas (n = 9) and cancers (p < 0.0001). EGFR overexpression was reported in 100% of cancers, 77.8% of HGD, and 10% of LGD adenomas. By multivariate analysis in adenomas, associated factors with EGFR overexpression were HGD and tubulo-villous feature.

MATERIALS AND METHODS

All patients undergoing colonoscopy in the university center of Saint-Etienne were eligible to the study from December 2015 to March 2016. In patients with colorectal neoplasia (lesions group), biopsies were performed on the lesion before its resection, and on the adjacent and distal colon mucosa. In control group, biopsies were performed in the right and left side colon. The EGFR expression was assessed by immunohistochemical scores (Goldstein grade, intensity of staining, composite score), using a primary mouse monoclonal antibody (EGFR, clone 113, Novocastra). Outcomes were compared using Kruskal-Wallis and/or Mann-Whitney-U tests, appropriately. The associated clinical, endoscopic and histological factors with EGFR overexpression (composite score ≥ 6) were assessed for adenomas by logistic regression.

CONCLUSIONS

EGFR are early involved in colorectal carcinogenesis, and their expression is strongly correlated to the neoplasia stage, leading to validate EGFR as an interesting surface biomarker of adenomas.

Expression and Function of the Epidermal Growth Factor Receptor in Physiology and Disease

The epidermal growth factor receptor (EGFR) is the prototypical member of a family of membrane-associated intrinsic tyrosine kinase receptors, the ErbB family. EGFR is activated by multiple ligands, including EGF, transforming growth factor (TGF)-α, HB-EGF, betacellulin, amphiregulin, epiregulin, and epigen. EGFR is expressed in multiple organs and plays important roles in proliferation, survival, and differentiation in both development and normal physiology, as well as in pathophysiological conditions. In addition, EGFR transactivation underlies some important biologic consequences in response to many G protein-coupled receptor (GPCR) agonists. Aberrant EGFR activation is a significant factor in development and progression of multiple cancers, which has led to development of mechanism-based therapies with specific receptor antibodies and tyrosine kinase inhibitors. This review highlights the current knowledge about mechanisms and roles of EGFR in physiology and disease.

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

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.

EGFR Overexpressed in Colonic Neoplasia Can be Detected on Wide-Field Endoscopic Imaging

OBJECTIVES

Colorectal cancer initially lies dormant as dysplasia, a premalignant state that provides an opportunity for early cancer detection. Dysplasia can be flat in morphology, focal in size, and patchy in distribution, and thus it appears "invisible" on conventional wide-field endoscopy.

AIMS

We aim to develop and validate a peptide that is specific for epidermal growth factor receptor (EGFR), a cell surface target that is overexpressed in colonic adenomas and is readily accessible for imaging.

METHODS

We expressed and purified the extracellular domain of EGFR for use with phage display to identify a peptide QRHKPRE that binds to domain 2 of this target. A near-infrared fluorescence endoscope was used to perform in vivo imaging to validate specific peptide binding to spontaneous colonic adenomas in a mouse model with topical administration. We also validated specific peptide binding to human colonic adenomas on immunohistochemistry and immunofluorescence.

RESULTS

After labeling with Cy5.5, we validated specific peptide binding to EGFR on knockdown and competition studies. Peptide binding to cells occurred within 2.46 min and had an affinity of 50 nm. No downstream signaling was observed. We measured a target-to-background ratio of 4.0±1.7 and 2.7±0.7, for polyps and flat lesions, respectively. On immunofluorescence of human colonic specimens, greater intensity from peptide binding to dysplasia than normal was found with a 19.4-fold difference.

CONCLUSIONS

We have selected and validated a peptide that can be used as a specific contrast agent to identify colonic adenomas that overexpress EGFR in vivo on fluorescence endoscopy.

Serine Protease Inhibitor Kazal Type 1 (SPINK1) Promotes Proliferation of Colorectal Cancer Through the Epidermal Growth Factor as a Prognostic Marker

Serine protease inhibitor Kazal type-1 (SPINK1), a trypsin kinase inhibitor, is involved in inflammation, cell proliferation and carcinogenesis. The role and association between SPINK1, EGFR and Ki-67 in colorectal adenoma (CRA) and colorectal cancer (CRC) are still unknown. In this study, we used immunohistochemical stain to evaluate expression of SPINK1, EGFR and Ki-67 proteins in 30 CRA and 53 CRC patients semiquantitatively, and then analyzed their correlation with clinicopathologic parameters. Our results revealed that SPINK1 expression was noted in the upper and basal parts of the crypts in CRA and was more intensely related with cellular atypia. EGFR expression was found in 13 out of 30 adenomas, including 9 out of 15 adenomas with dysplasia or synchronous CRC (60 %), and 4 out of 15 adenomas without dysplasia (26.7 %). In CRC, high SPINK1 expression was significantly associated with males (p = 0.041) and advanced disease stage (p = 0.015). EGFR positivity was significantly correlated with higher T stage (p = 0.004) and disease stage (stage I-IV, p = 0.017; early vs. late, p = 0.015). Pearson's correlation showed positive correlation between the SPINK1 intensity and EGFR immunoreactivity (p = 0.011), and Ki-67 and SPINK1 intensity or percentage (p = 0.017 and p = 0.039 respectively). In Kaplan-Meier analyses, patients with high SPINK1 intensity tended to have shorter overall survival (p = 0.03). Concomitant expression of high SPINK1 intensity and EGFR was also identified as being associated with poor prognosis (p = 0.015). In conclusion, high SPINK1 expression is associated with advanced stage and poor prognosis. There is positive correlation between high SPINK1 expression, EGFR immunoreactivity, and high Ki-67 labeling index. The SPINK1 protein seems to play a role in tumor proliferation and malignant transformation through the EGFR pathway. SPINK1 may serve as a prognostic biomarker in therapeutic targeting in the future.

Epidermal growth factor receptor (EGFR) gene copy number in colorectal adenoma-carcinoma progression

Adenomas are the easily identifiable precursors of the vast majority of colorectal cancers. Some of their morphological features, such as dysplasia, are predictive of their biological evolution toward adenocarcinomas. A large body of evidence has demonstrated that the epidermal growth factor receptor (EGFR) signaling pathway is commonly activated in colorectal cancer and EGFR-target therapies have improved the outcome for colorectal cancer patients. Nevertheless, the mechanisms underlying the role of EGFR in the adenoma-carcinoma sequence are not entirely clear. We retrospectively analyzed EGFR gene copy number by fluorescence in situ hybridization (FISH) in paraffin-embedded tissue from 215 patients recruited through a prospective colorectal cancer screening procedure and undergoing surgical colectomy. We observed that in human colorectal carcinogenesis, EGFR copy number increases progressively, from adenomas with high-grade dysplasia to locally advanced adenocarcinomas, through early invasive adenocarcinomas, suggesting that deregulation of EGFR may correlate with the malignant progression.

Thermostable direct hemolysin diminishes tyrosine phosphorylation of epidermal growth factor receptor through protein kinase C dependent mechanism

BACKGROUND

Adequate evidence mounts to the fact that several bacteria and their toxins have protective or curative roles in colorectal cancers. Thermostable direct hemolysin (TDH), produced by Vibrio parahaemolyticus, down regulates cell proliferation in colon carcinoma cell lines. TDH induces Ca2+ influx from an extracellular environment accompanied by protein kinase C phosphorylation. Activated protein kinase C inhibits the tyrosine kinase activity of epidermal growth factor receptor (EGFR), the rational target of anti-colorectal cancer therapy.

METHODS

Immunoblotting analyses were performed to ascertain protein kinase C activation, EGFR status, EGFR phosphorylation and mitogen activated protein kinase (MAPK) activity. Flow cytometry analysis and ELISA reconfirmed tyrosine phosphorylation of EGFR and ERK activations, respectively. PKC-α siRNA knockdown was done to corroborate the involvement of PKC-α in the undertaken study.

RESULTS

Our study showed the translocation of PKC-α from cytosol to the membrane fraction in colon carcinoma cell lines on incubation with TDH. The EGFR tyrosine kinase activity exhibited a down regulation on TDH treatment which involved PKC-α, as confirmed by siRNA knockdown. Also ERK phosphorylation occurred on PKC-α activation.

CONCLUSION

TDH activated PKC-α down regulates EGFR tyrosine kinase activity by MEK dependent mechanism involving MAPK.

GENERAL SIGNIFICANCE

In this study we have seen that TDH has an implication in EGFR based therapeutic approach in colorectal cancer via PKC mediated mechanism.