Markers of Fibroblast Growth Factor Family-Mediated Growth Signal Transduction asDeterminants of Successful Hormonal Therapy for Patients with Estrogen Receptor Positive Breast Cancer

摘要

To determine whether FGFR-3 expression correlated with antiestrogen resistance,two high titer polyclonal rabbit antibodies were generated against two peptides present in the FGFR-3 protein. Pathological specimens from 181 patients with estrogen receptor positive breast tumors that received tamoxifen therapy were identified. H+E stained sections were evaluated and tumor tissue sections were prepared from paraffin embedded material from over 100 patients. To determine the suitability of the FGFR-3 antibodies for use in immunohistochemical as says with sections from formalin-fixed and paraffin-embedded material, we sought to establish a tumorigenic cell line that overexpressed FGFR-3 for use as a positive control. A cDNA clone purported to contain the complete coding sequence for FGFR-3 was inserted into a eucaryotic expression vector. MCF-7 breast carcinoma cells transfected with this vector were characterized but no protein expression was observed due to an unexpected insertion of DNA into the coding region of the cDNA. Reverse transcription-polymerase chain reaction (RT-PCR) was used to generate plasmid transcription vectors for FGF-7 and a FGFR-2 splice variant that generates a specific receptor for FGF-7. These vectors were used to prepare probes for RNAse protection assays for FGF-7 and its receptor. The presence of FGF-7 RNA was detected in 35 of 36 human breast tumors examined. The probe for the FGFR-2 splice variant was not suitable for the RNAse protection assay. A semiquantitative RT-PCR assay that was developed as an alternative showed expression of the FGF-7 specific receptor in six of nine tumors examined.