Expression of miR-26a exhibits a negative correlation with HMGA1 and regulates cancer progression by targeting HMGA1 in lung adenocarcinoma cells

Lung cancer is the most common cause of cancer-associated mortality worldwide, and the number of cases is increasing annually. Several studies have shown that microRNAs (miRNAs) control proliferation, differentiation, and apoptosis in various cell types, and increasing evidence indicates the presence of aberrant miRNA expression profiles and unique miRNA signaling pathways in several types of cancer. The present study aimed to identify miRNAs, which correlated specifically with the progression of lung cancer through the analysis of 57,100 transcripts and 1,341 small RNA expression profiles in 26 lung adenocarcinoma cell lines using next-generation sequencing. The most marked negative correlation was found between the expression of hsa-miR-26a-1 and messenger RNA (mRNA), and a list of mRNAs, which exhibited negative correlation with hsa-miR-26a-1 were investigated. The most marked negative correlation was observed between the expression levels of hsa-miR-26a-1 and high mobility group A1 (HMGA1). Using a lung adenocarcinoma cell line, the present study analyzed the effect of the overexpression of miR-26a on the expression of HMGA1 and found that miR-26a repressed the expression of HMGA1 by reducing the mRNA levels of HMGA1. Furthermore, it was demonstrated that the overexpression of miR-26a in a lung adenocarcinoma cell line repressed cell migration, invasion and growth by targeting HMGA1. Taken together, the present study showed a significant negative correlation between the expression of miR-26a and HMGA1 in 26 lung adenocarcinoma cell lines, and provided evidence that the suppression of miR-26a supports the progression of cancer by stimulating the expression of HMGA1.