Poster lunch (ID 46) Poster display session

38P - Defining the physiological miRNA landscape in nipple aspirate fluid (ID 409)

Presentation Number
38P
Lecture Time
12:15 - 12:15
Speakers
  • Susana I. Patuleia (Utrecht, Netherlands)
Session Name
Poster lunch (ID 46)
Location
Exhibition area, MARITIM Hotel Berlin, Berlin, Germany
Date
03.05.2019
Time
12:15 - 13:00

Abstract

Background

MicroRNAs (miRNAs) are small, non-protein-coding RNAs that can bind and suppress specific target messenger RNAs (mRNAs). Their dysregulation has been shown to affect the hallmarks of cancer and an increasing number of studies have identified miRNAs as potential biomarkers for cancer diagnosis. The ability to detect local oncogenic or tumor suppressor miRNAs in nipple aspirate fluid (NAF) could be of great value for early breast cancer diagnosis. To define the landscape of miRNAs physiologically present in the breast ducts, we analyzed their expression patterns in healthy NAF samples.

Methods

A total of 41 NAF samples (8 ng total RNA) from healthy women were profiled using the TaqMan™ OpenArray™ Human Advanced MicroRNA Panel (ThermoFisher Scientific) targeting 754 human mature miRNAs. Non-parametric statistical analyses were performed using SPSS statistics®.

Results

Out of the 754 interrogated miRNAs, 39% had measurable expression levels in NAF. In line with previous miRNA studies in breast milk, the majority of highly expressed miRNAs in NAF (36/top 50) have immune-related roles. Few of the top 50 miRNAs in NAF were significantly correlated with BMI (miR-223-3p) or parity (let-7b-5p, miR-92a-3p, miR-29b-3p and miR-30d-5p). No correlation was found between miRNA expression and age or having a first degree relative with breast cancer. Interestingly, NAF sample color significantly affected the expression level of 4/50 miRNAs. MiR-205-5p, miR-200b-3p, miR-26a-5p and miR-210-3p showed significantly lower expression levels in green or brown samples compared to bloody, orange or pink samples (p = 0.029, p = 0.022, p = 0.011, and p = 0.009, respectively).

Conclusions

MiRNAs can reliably be detected in NAF of healthy subjects and most of them are immune-related. Our data reveals the first documented NAF-derived miRNA physiological expression pattern, with very few highly expressed miRNAs associated with established breast cancer risk factors. Of note, caution should be taken when interpreting miRNA expression levels in differently colored samples, as this proves to be a significant confounder. Currently, breast cancer NAF samples are being collected in the context of a Dutch trial and their analysis will soon reveal whether breast cancer specific miRNAs can be identified.

Clinical trial identification

METC 14-497 (Dense-on) and METC 16-337 (Ornament).

Legal entity responsible for the study

Department of Pathology, UMC Utrecht.

Funding

Pink Ribbon, KWF.

Disclosure

All authors have declared no conflicts of interest.

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