Pathway Analysis of Selected Circulating miRNAs in Plasma of Breast Cancer Patients: A Preliminary Study.

Veronika Holubekova,Martina Bobrovska,Marianna Jagelkova,Erik Kudela,Marek Samec,Zuzana Kolkova,Alena Liskova,Zuzana Laucekova,Michal Kalman,Dusan Brany,Michal Kalman,Zuzana Dankova,Martina Bobrovska,Marianna Jagelkova,Dana Dvorska,Katarina Zelinova,Igor Stastny,Igor Stastny,Marian Grendar,Pavol Zubor

doi:10.3390/ijms21197288

Abstract

MicroRNAs in the circulation of breast cancer (BC) patients have great potential for the early diagnosis, treatment and monitoring of breast cancer. The aim of this preliminary study was to obtain the expression profile of selected miRNAs in the plasma of BC patients that could discriminate BC patients from healthy volunteers and may be useful in early detection of BC. Significantly deregulated miRNAs were evaluated by pathway analysis with the prediction of potential miRNA targets. The study enrolled plasma samples from 65 BC patients and 34 healthy volunteers. Selected miRNAs were screened in pilot testing by the real-time PCR (qPCR) method, and the most appropriate reference genes were selected for normalisation by the geNorm algorithm. In the final testing, we detected miR-99a, miR-130a, miR-484 and miR-1260a (p < 0.05) as significantly up-regulated in the plasma of BC patients. Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis revealed that all significantly deregulated miRNAs are involved in the Hippo and Transforming Growth Factor-beta (TGF-beta) signalling pathways. Our study confirmed a different profile of selected circulating miRNAs in the plasma of BC patients with an emphasis on some critical points in the analysis process.

Highlights

Breast cancer is the leading gynaecologic cancer disease worldwide with an estimated incidence of 46.3 age-standardised rate (ASR) and estimated mortality of 13.0 ASR per 100,000 women [1]
A total of 99 women of the Caucasian race were recruited in the study, including 65 patients with breast cancer (BC) and 34 normal patients
The composition based on the molecular subtypes of BC was as follows: 63% (33/65) patients were classified as luminal A, 25% (13/65) patients were luminal B, 7.7% (4/65) patients were human epidermal growth factor receptor 2 (HER2) positive and 3.8% (2/65) were triple-negative cancers (TNC)

Summary

Introduction

Breast cancer is the leading gynaecologic cancer disease worldwide with an estimated incidence of 46.3 age-standardised rate (ASR) and estimated mortality of 13.0 ASR per 100,000 women [1]. A higher incidence of BC is seen in developed countries [2], which according to one theory, could be associated with higher socioeconomic status and better availability and accuracy of screening examinations (mammography, ultrasound examination and magnetic resonance imaging) and life expectancy, as the risk for BC increases after 50 years of life [3]. Breast cancer is heterogeneous disease comprising phenotypically diverse tumours categorised into molecular subtypes based on the overexpression of receptors for the hormones oestrogen (ER) or progesterone (PR), or for the human epidermal growth factor receptor 2 (HER2). Molecular subtypes of BC are important in the definition of therapy indications, as systematic treatment recommendations, risk and predictive factors should be considered [4]

Methods

Results

Conclusion