Five serum-based miRNAs were identified as potential diagnostic biomarkers in gastric cardia adenocarcinoma.

Background: Circulating microRNAs (miRNAs) have been implicated as novel biomarkers for various types of cancers. The aim of the study is to identify serum miRNAs with potential in detecting gastric cardia adenocarcinoma (GCA).

Methods: A three-phase study was designed with 102 GCA patients and 84 cancer-free controls. In the screening phase (3 GCA pools vs. 1 normal control (NC) pool), a total of 35 miRNAs were identified using quantitative reverse transcription polymerase chain reaction (qRT-PCR) based Exiqon panel. Subsequently, these miRNAs were further assessed by qRT-PCR in the training phase (30 GCAs vs. 30 NCs) and testing phase (72 GCAs vs. 54 NCs). Finally, the expression levels of the identified miRNAs were assessed in GCA tissues and exosomes.

Results: Five up-regulated miRNAs (miR-200a-3p, miR-296-5p, miR-132-3p, miR-485-3p and miR-22-5p) were identified in serum of the GCA patients compared with NCs. The areas under the receiver operating characteristic curve (AUCs) of the five-miRNA panel were 0.766 and 0.724 for the training and testing phases, respectively. In addition, miR-200a-3p, miR-296-5p, miR-485-3p and miR-22-5p were significantly up-regulated in GCA tissues. However, none of the miRNAs in the exosomes showed different expression between GCA patients and NCs.

Conclusions: We identified a five-miRNA panel in peripheral serum samples as a non-invasive biomarker in detection of GCA.