Expression of EGF-receptor related protein (ERRP) decreases in gastric mucosa during aging and carcinogenesis

EGFR(s) in aging and carcinogenesis of the gastrointestinal tract

Cells of the gastrointestinal (GI) mucosa are subject to a constant process of renewal which, in normal adults, reflects a balance between the rates of cell production and cell loss. Detailed knowledge of these events is, therefore, essential for a better understanding of the normal aging processes as well as many GI diseases, particularly malignancy, that represent disorders of tissue growth. In general, many GI dysfunctions, including malignancy, increase with advancing age, and aging itself is associated with alterations in structural and functional integrity of the GI tract. Although the regulatory mechanisms for age-related increase in the incidence of GI-cancers are yet to be fully delineated, recent evidence suggests a role for epidermal growth family receptors and its family members {referred to as EGFR(s)} in the development and progression of carcinogenesis during aging. The present communication discusses the involvement of EGFR(s) in regulating events of GI cancers during advancing age and summarizes the current available therapeutics targeting these receptors. The current review also describes the effectiveness of ErbB inhibitors as well as combination therapies. Additionally, the involvement of GI stem cells in the development of the age-related rise in GI cancers is emphasized.

Is stomach spontaneously ageing? Pathophysiology of the ageing stomach

During ageing, histological and physiological modifications occur in the stomach leading to a confirmed state of gastric frailty defined by a decreased capacity of tissue repairing after mucosa gastric aggression. The process of intrinsic gastric ageing may play a role in inducing abnormalities of gastric epithelial proliferation against injury but, most of the time, pathophysiological modifications observed in older people are the consequences of chronic insults, such as chronic Helicobacter pylori infection, polymedication, especially Proton-pump inhibitors (PPI) and Non-steroidal Anti-inflammatory Drugs (NSAID), and co morbidities. One of the major clinical consequences of the gastric frailty is the higher vulnerability to the occurrence of peptic ulcer disease during ageing. In this review recent data on gastric changes during ageing, focussing especially on histological modifications and motility disorders are summarized.

Emerging therapies in gastrointestinal cancers

Members of the receptor tyrosine kinase family, that include EGFR, ErbB-2/HER-2, ErbB-3/HER-3 and ErbB-4/HER-4, are frequently implicated in experimental models of epithelial cell neoplasia as well as in human cancers. Therefore, interference with the activation of these growth factor receptors represents a promising strategy for development of novel and selective anticancer therapies. Indeed, a number of inhibitors that target either EGFR or HER-2, with the exception of a few that target both; have been developed for treatment of epithelial cancers. Since most solid tumors express different ErbB receptors and/or their ligands, identification of inhibitor(s), targeting multiple EGFR family members may provide a therapeutic benefit to a broader patient population. Here we describe the significance of an ErbB family of receptors in epithelial cancers, and summarize different available therapeutics targeting these receptors. It also emphasizes the need to develop pan-ErbB inhibitors and discusses EGF-Receptor Related Protein, a recently isolated negative regulator of EGFR as a potential pan-ErbB therapeutic for a wide variety of epithelial cancers.

Does the EGFR and VEGF expression predict the prognosis in colon cancer?

BACKGROUND/AIM

Epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) are frequently encountered with aggressive tumor phenotype and poor prognosis, but the relationship between EGFR/VEGF expression and survival remains unclear. The aim of our study was to further investigate the prognostic value of EGFR and VEGF expression in colon cancer.

MATERIALS AND METHODS

The pathological specimens of 60 colon carcinoma patients were retrospectively evaluated and grouped according to EGFR and VEGF staining intensity and percentage of stained neoplastic cells. A final score was assigned to each case by multiplying percentage and staining score. The patients were stratified into the following categories: negative (score 0), low expression (score 1 or 2), and high expression (score 4). The remaining patient data were filtered out from the institutional cancer database.

RESULTS

The mean survival time was 28.93 +/- 14.1 (range 2-52) months in the EGFR-negative group, 23.92 +/- 14.0 (range 6-46) months in the group with a low EGFR expression, and 17.00 +/- 12.8 (range 10-40) months in the group with a high EGFR expression. The median survival time was 27.50 +/- 14.7 (range 4-52) months in the VEGF-negative group, 29.33 +/- 12.8 (range 6-48) months in the group with a low VGEF expression, and 14.50 +/- 14.2 (range 2-40) months in the group with a high VGEF expression. The expression of EGFR and VEGF was not an independent factor that affects survival.

CONCLUSIONS

The EGFR and VEGF expression rates of colon tumors do not predict the survival. In addition, the EGFR expression in the primary tumor was not predictive of metastatic lymph nodes. The prognostic value of EGFR/VEGF staining may be further questioned.

Therapeutic potential of EGFR-related protein, a universal EGFR family antagonist

Interference with the activation of growth factor receptors, specifically epidermal growth factor receptor (EGFR) and/or other member(s) of its family (human epidermal growth factor [HER]-2, -3 and -4) represents a promising strategy for development of novel and selective anticancer therapies. Indeed, a number of inhibitors that target either EGFR or HER-2, but not both, have been developed for treatment of epithelial cancers. However, since most solid tumors express different EGFRs, identification of inhibitor(s) targeting multiple EGFR family members may provide a therapeutic benefit to a broader patient population. To this end, the author proposes that EGFR-related protein (ERRP), a recently isolated negative regulator of EGFR that possesses a substantial homology to the extracellular ligand-binding domain of EGFR and its family members, is a pan-ErbB inhibitor that targets multiple members of the EGFR family. This review discusses the significance of EbB [corrected] family of receptors in epithelial cancers, and describes isolation, characterization and the mechanisms of action of ERRP as well as its potential application as a therapeutic agent for a wide variety of epithelial cancers.

Age-related loss of EGF-receptor related protein (ERRP) in the aging colon is a potential risk factor for colon cancer

Although in Fischer-344 rats, aging is associated with increased activation of EGF-receptor (EGFR) in mucosa of much of the gastrointestinal tract, including the colon, regulation of this process is poorly understood. We hypothesize that loss of suppressor of EGFR may partly be responsible for this process. To test this hypothesis, we examined the expression of EGFR related protein (ERRP), a recently identified negative regulator of EGFR, in the colonic mucosa during aging and following administration of the colonic carcinogen dimethylhydrazine (DMH) that resulted in the formation of aberrant crypt foci (ACF), which are considered to be precursor of adenoma and carcinoma. In Fischer-344 rats, aging is associated with increased activation of EGFR in the colonic mucosa, as evidenced by 30-35% increase in the levels of tyrosine phosphorylated EGFR in the proximal and distal colon of aged (20-22 months old) than in young (4-6 months old) rats. In contrast, the levels of ERRP in both regions of the colon of aged rats were decreased by 50-60%, compared to their younger counterparts. Administration of DMH, which induced a greater number of ACF in the colon of aged rats than in young animals, resulted in a corresponding reduction in ERRP in the colon. These results suggest that loss of ERRP expression is a common event during aging and early stages of chemically induced colon cancer. We also suggest that loss of ERRP could be a risk factor for developing colorectal cancer in the older population.

Expression of epidermal growth factor-receptor related protein (ERRP) in human colorectal carcinogenesis

We hypothesize that ERRP (EGFR-related protein), a recently identified negative regulator of EGFR may modulate EGFR function in colorectal carcinogenesis. The expression of ERRP and EGFR in normal and neoplastic colorectal tissue was examined. ERRP was highly expressed in normal colonic mucosa and benign colorectal adenomas, but lower in colorectal cancer. Mean scores for ERRP expression decreased significantly across well differentiated, moderately well differentiated and poorly differentiated (P = 0.002) tumors, respectively. ERRP expression became more attenuated in polyps with increasing grades of dysplasia. In contrast, expression of EGFR was inversely related to ERRP in representative samples of normal and neoplastic tissues.