Detection of biomarker gene expression by real-time polymerase chain reaction using amplified ribonucleic acids from formalin-fixed random periareolar fine needle aspirates of human breast tissue.

OBJECTIVE

To address the detection of breast cancer biomarker gene expression in formalin-fixed random periareolar fine needle aspiration (RPFNA) samples of benign breast tissue collected during breast cancer prevention trials by quantitative real-time polymerase chain reaction (qPCR).

STUDY DESIGN

Formalin-fixed breast epithelial cells collected by RPFNA and processed as thin layer preparations were isolated by laser capture microdissection (LCM). Ribonucleic acid (RNA) was extracted and amplified using a single round of T7-based linear amplification followed by quality assessment and biomarker assay using TaqMan chemistry.

RESULTS

More than 80% of RPFNA samples yielded RNA of sufficient quantity and quality for measurement of a panel of biomarker genes following a single round of linear amplification. RNA and protein expression for estrogen receptor alpha, as assessed by LCM/qPCR and immunohistochemistry, were correlated. Amplification plots were similar for cDNA standards and cDNA derived from RPFNA samples.

CONCLUSION

Assessment of gene expression using amplified RNA from microdissected formalin-fixed RPFNAs can increase the number of biomarkers used during breast cancer chemoprevention trials.