Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
Board

Several variant forms of the estrogen receptor alpha (ER-alpha) mRNA have been described in human breast tissues. Among these, ER-alpha mRNA variants truncated after sequences encoding exon 2 of the wild-type ER-alpha mRNA (ERC4 mRNA), or deleted in exon 3 (ERD3 mRNA) or exon 5 (ERD5 mRNA) sequences, were previously shown to be differentially expressed between independent normal and breast tumor tissues. Using semi-quantitative reverse transcription-polymerase chain reaction assays, we have investigated the expression of these variant mRNAs relative to wild-type ER-a mRNA in 18 samples of normal breast tissues and their adjacent matched breast tumor tissues. A general trend towards a higher ERC4 mRNA and a lower ERD3 mRNA relative expression in the tumor compartment was observed. These differences reached statistical significance when considering only the ER-positive/progesterone receptor positive (p=0.019) and the ER-positive (p=0.023) subsets, as measured by the ligand binding assay, respectively. A significantly (p=0.035) higher ERD5 mRNA relative expression was observed in tumor components overall. These data confirm previous observations and demonstrate that changes in the expression of ER-alpha variant mRNAs relative to wild-type occur between adjacent normal and neoplastic breast tissues.

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Poster Number PAleygue0756
Keywords: estrogen receptor, breast cancer, tumor progression, variant mRNA