Expression of human epidermal growth factor and its receptor in esophageal cancer

Expression, regulation and targeting of receptor tyrosine kinases in esophageal squamous cell carcinoma

Esophageal cancer is one of the most common types of cancer, which is a leading cause of cancer-related death worldwide. Based on histological behavior, it is mainly of two types (i) Esophageal squamous cell carcinoma (ESCC), and (ii) esophageal adenocarcinoma (EAD or EAC). In astronomically immense majority of malignancies, receptor tyrosine kinases (RTKs) have been kenned to play a consequential role in cellular proliferation, migration, and metastasis of the cells. The post-translational modifications (PTMs) including phosphorylation of tyrosine (pY) residue of the tyrosine kinase (TK) domain have been exploited for treatment in different malignancies. Lung cancer where pY residues of EGFR have been exploited for treatment purpose in lung adenocarcinoma patients, but we do not have such kind of felicitously studied and catalogued data in ESCC patients. Thus, the goal of this review is to summarize the studies carried out on ESCC to explore the role of RTKs, tyrosine kinase inhibitors, and their pertinence and consequentiality for the treatment of ESCC patients.

Expression, regulation and targeting of receptor tyrosine kinases in esophageal squamous cell carcinoma

Esophageal cancer is one of the most common types of cancer, which is a leading cause of cancer-related death worldwide. Based on histological behavior, it is mainly of two types (i) Esophageal squamous cell carcinoma (ESCC), and (ii) esophageal adenocarcinoma (EAD or EAC). In astronomically immense majority of malignancies, receptor tyrosine kinases (RTKs) have been kenned to play a consequential role in cellular proliferation, migration, and metastasis of the cells. The post-translational modifications (PTMs) including phosphorylation of tyrosine (pY) residue of the tyrosine kinase (TK) domain have been exploited for treatment in different malignancies. Lung cancer where pY residues of EGFR have been exploited for treatment purpose in lung adenocarcinoma patients, but we do not have such kind of felicitously studied and catalogued data in ESCC patients. Thus, the goal of this review is to summarize the studies carried out on ESCC to explore the role of RTKs, tyrosine kinase inhibitors, and their pertinence and consequentiality for the treatment of ESCC patients.

Increase of epidermal growth factor receptor expression in progression of GERD, Barrett, and adenocarcinoma of esophagus

INTRODUCTION

Gastroesophageal reflux disease (GERD) is a pathology with a wide range of clinical and endoscopic manifestations. Epidermal growth factor receptor (EGFR), found in the epithelium of the digestive tract, plays an important role in epithelial repair and shows increased expression in different neoplasms, including esophageal tumors.

OBJECTIVES

The purpose of this study was to evaluate EGFR expression using immunohistochemistry in esophageal biopsies obtained from patients with GERD, Barrett's esophagus, and adenocarcinoma of the esophagus.

METHODS

EGFR expression was immunohistochemically determined in biopsies from 194 patients with symptoms suggestive of GERD or adenocarcinoma of the esophagus, seen at two Brazilian university hospitals between January 2003 and December 2008. Based on histopathological analysis, patients were divided into three groups: GERD, Barrett's esophagus and adenocarcinoma of the esophagus. EGFR expression was considered positive when staining was detected in the membrane.

RESULTS

Mean age was 55.25 years (range 30-90). Patients with GERD (n = 127) accounted for 65.5% of the sample, compared with 12.4% (n = 24) of patients with Barrett's esophagus and 22.2% (n = 43) of patients with esophageal adenocarcinoma. Immunohistochemical analysis was positive for EGFR in 19.1% of the patients (37/194), divided as follows: 8.7% (11/127) in the GERD group, 25% (6/24) in the Barrett's esophagus group, and 46.5% (20/43) in the esophageal adenocarcinoma group. Statistical analysis revealed significant differences between the three groups (p = 0.0001).

CONCLUSIONS

GERD patients showed lower levels of EGFR expression than patients with Barrett's esophagus or patients with adenocarcinoma of the esophagus, suggesting a direct relationship between EGFR expression and disease progression.

Activation of growth factor receptors in esophageal cancer--implications for therapy

Esophageal cancer is a highly aggressive disease and is the seventh most common cause of cancer-related death in the western world. Worldwide, it ranks as the sixth most frequent cause of cancer death. Despite advances in surgical techniques and treatment, the prognosis of esophageal cancer remains poor, with very few long-term survivors. The need for novel strategies to detect esophageal cancer earlier and to improve current therapy is urgent. It is well established that growth factors and growth factor receptor-mediated signaling pathways are important components of the transformation process in many forms of cancer, including esophageal cancer. With the recent advances in drug development, there are emerging possibilities to use growth factor signal transduction pathways in targeted therapy. This review provides a summary of the role of growth factors and their receptors in esophageal cancer and discusses their potential roles as biomarkers and as targets in therapy.

Expression of epidermal growth factor, transforming growth factor-alpha and their receptor in the human oesophagus

Increasing evidence indicates that epidermal growth factor and transforming growth factor-alpha are involved in the maintenance of oesophageal mucosal integrity. However, their cellular origin and the exact localization of their receptor in the oesophagus are still unclear. Therefore, we examined the expression of the two growth factors and their shared receptor in the normal human oesophagus at both mRNA and protein level, by immunohistochemistry, in situ hybridization and reverse transcription-polymerase chain reaction. In addition to being expressed in the proliferative compartment of the oesophageal epithelium, the receptor was found in a variety of cells, including smooth muscle cells, submucosal gland cells and the epithelium lining their ducts. Immunohistochemically, the pattern of distribution of epidermal growth factor paralleled that of its receptor. In situ hybridization demonstrated epidermal growth factor mRNA expression in the oesophageal epithelium and submucosal glands. Additionally, amplified transcripts of predicted size were detected by reverse transcription-polymerase chain reaction, thus confirming that authentic transcripts of the growth factor exist in the normal human oesophagus. Transforming growth factor-alpha mRNA and protein expression, while similar to that of epidermal growth factor, predominated in the more differentiated cell layers of the stratified squamous epithelium. These results demonstrate that the normal oesophagus can synthesize both growth factors. Moreover, the peculiar distribution of these peptides and the concomitant expression of their receptor in multiple cell types suggest that the two growth factors may exert diverse physiological functions in the oesophagus and participate in defence and reparative events following mucosal injury.

Immunohistochemical investigation of epidermal growth factor receptor expression in ameloblastomas

Immunohistochemical analysis was performed to determine the localization of epidermal growth factor receptor (EGFR) in ameloblastomas. Ameloblastoma samples were classified into follicular, plexiform, and basal cell types. The number of cases in each category was 17, 19 and 3, respectively. Ameloblastomas, disregarding their histological type, consist of two cell forms: peripheral columnar cells and central stellate cells. The frequency of EGFR expression was much higher in the latter than in the former (P < 0.005). On analysis with respect to histological types, the frequency of EGFR expression in columnar cells was not significantly different between the follicular and the plexiform types, but was observed more frequently in the stellate cells in the follicular than in the plexiform ameloblastomas (P < 0.05). This pattern of EGFR expression was not consistent with the PCNA staining pattern, but was similar to that of keratin expression which we have reported previously. The present study suggests that EGFR expression in ameloblastomas is closely associated with tumour differentiation, and squamous differentiation in particular.

Production of matrix metalloproteinase-2 and metalloproteinase-3 related to malignant behavior of esophageal carcinoma. A clinicopathologic study

BACKGROUND

Matrix metalloproteinases (MMP) are a gene family of zinc enzymes capable of degrading almost all of the extracellular matrix macromolecules in vivo. Their enzymic activities are believed to be responsible for tumor invasion and metastasis.

METHODS

In this study, using peroxidase-antiperoxidase method, monospecific antisera against MMP-1 (tissue collagenase), MMP-2 (type IV collagenase/72-kilodalton [KD] gelatinase), and MMP-3 (stromelysin) were applied to 29 squamous cell carcinomas and normal epithelium of the esophagus to identify cells synthesizing and secreting these enzymes.

RESULTS

Immunoreactivity of MMP-1, -2, and -3 was observed in small cancer nests of the deeply invasive or marginal portion of the tumor. Among the 29 patients studied, the presence of at least one MMP was observed in 17 (58.6%). All three enzymes were observed in six (20.6%) patients, MMP-2 and -3 in five (17.2%) patients, only MMP-2 in three (10.3%) patients, and MMP-3 alone in three (10.3%) patients. There was a good correlation among histologic stage and tumor invasion, lymph node metastasis, and MMP expression. In particular, expression of MMP-2 and -3 was closely related to lymph node metastasis and vascular invasion.

CONCLUSIONS

These results suggest that MMP, especially MMP-2 and -3, play an important role in tumor invasion and metastasis and that analysis of MMP-2 and -3 production is useful for evaluation of malignant potential in esophageal carcinoma.