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Growth factor receptors and their ligands
1Department of Gynecology, Kantonsspital, Basel, Switzerland.
Abstract:
The understanding of the signal transduction cascade involving growth factors and their receptors is one major key for diagnostic and therapeutic improvements in human neoplasms. Using receptor autoradiography, an inverse relationship for the incidence of somatostatin receptors (SSR) and epidermal growth factor receptors (EGFR) was found in gliomas [1]. In the majority of low grade gliomas, SSR were present but EGFR were absent. In contrast, EGFR were present in most glioblastomas, but no SSR were detected. Recently, the amplification of the EGFR gene and its overexpression was demonstrated to be associated with the development of glioblastomas. Several independent reports revealed that 40-50% of tumors show amplified EGFR [2-4]. The frequency of EGFR amplification was directly associated with tumor malignancy. In addition, amplified EGFR levels indicate a bad prognosis and shorter overall survival [5]. Recent analysis of the EGFR gene in tumors has shown that regions of this gene frequently undergo alteration. Hence, not only amplification but also mutation may be the cause of the increased malignancy in EGFR overexpressing cells [6].
Insights
Gliomas show an inverse relationship between somatostatin receptors (SSR) and epidermal growth factor receptors (EGFR). High SSR levels correlate with low-grade gliomas, while high EGFR levels indicate glioblastomas with poor prognosis.
Area of Science:
- Oncology
- Molecular Biology
- Neuroscience
Background:
- Understanding growth factor signaling is crucial for cancer diagnostics and therapeutics.
- Signal transduction pathways involving growth factors and receptors are key in human neoplasms.
- Epidermal growth factor receptors (EGFR) and somatostatin receptors (SSR) play roles in glioma development.
Purpose of the Study:
- To investigate the relationship between somatostatin receptors (SSR) and epidermal growth factor receptors (EGFR) in gliomas.
- To explore the association between EGFR gene amplification, overexpression, and glioma malignancy.
- To determine the prognostic significance of EGFR alterations in gliomas.
Main Methods:
- Receptor autoradiography was used to assess the incidence of SSR and EGFR in gliomas.
- Analysis of EGFR gene amplification and overexpression in tumor samples.
- Correlation of EGFR gene alterations with tumor grade, malignancy, and patient survival.
Main Results:
- An inverse relationship was observed between SSR and EGFR in gliomas.
- Low-grade gliomas predominantly expressed SSR and lacked EGFR.
- Glioblastomas frequently exhibited EGFR but lacked SSR.
- EGFR gene amplification occurred in 40-50% of tumors, correlating with malignancy and poor prognosis.
- EGFR gene mutations were also implicated in increased malignancy.
Conclusions:
- The inverse expression of SSR and EGFR suggests distinct roles in glioma progression.
- EGFR amplification and overexpression are significant indicators of glioblastoma development and malignancy.
- EGFR alterations, including amplification and mutation, are associated with poor prognosis and reduced survival in glioma patients.