THE ROLE OF LET-7/HMGA2 LINKAGE IN THE PATHOGENESIS AND PROGNOSIS OF MYELODYSPLASTIC NEOPLASMS

Abstract

Introduction

MicroRNAs (miRNAs),are significant regulators of human hematopoietic stem cells. Their deregulation contributes to hematological malignancies.The let-7 family has been found frequently deregulated in malignancies.In MDS various alterations of miRNAs have been reported.High Mobility Group AT-Hook 2 (HMGA2) protein functions as a transcriptional regulator. In this study, we investigated the HMGA2 expression in MDS and specifically in patients with fibrosis we studied the prognostic significance of four members of the let-7 family (let-7a, let-7b, let-7c, let-7d).

Methods

RNA extraction, reverse transcription, anda SYBR Green based real-time PCR were performed for the absolute quantification of HMGA2, using standard protocols. After RNA polyadenylation and reverse transcription with an oligo-dT adapter primer, miRNAs transcript levels were determined using the SYBR Green chemistry. IBM SPSS statistics, version 26 (IBM Corporation, North Castle, NY, USA) was used for the analysis.

Results

HMGA2 gene expression was investigated in 78 patients with MDS, whereas transcript levels of four members of the let-7 family (let-7a, let-7b, let-7c, let-7d) were analyzed in 11 patients with fibrosis. Let-7a transcript levels were significantly higher in MDS patients who developed acute myeloid leukemia (AML) compared to the group that did not (p=0.0141). Let-7d presented a negative correlation (p=0.0408). A moderate (p =0.0483) negative correlation of HMGA2 with let-7c, and a strong positive correlation (p =0.0481) with let-7d, were observed.

Conclusions

In literature, the let-7/HMGA2 linkage could be a signature in MDS pathogenesis. Let-7a level was found higher in transformation to AML,defining it as a poor prognostic factor, in contrast with the protective role of high let-7d.