۱- Introduction

۲- Materials and methods

۳- Results

۴- Discussion

References

Abstract

Introduction: Long non-coding RNAs (lncRNAs) are RNA molecules that structurally resemble mRNA but do not encode proteins. Studies have been associated this class of non-coding RNA with the development of several disease, among them the different types of leukemia. However, the results are contradictory. Thus, we performed a systematic review of the literature available in order to better understand the involvement of lncRNAs in the development of leukemia. Materials and Methods: Pubmed and Embase databases were used to identify all studies that evaluated the expression of one or more lncRNA between human samples (peripheral blood, bone marrow) with leukemia (cases) and without leukemia (controls). Results: A total of 3675 articles were found in the databases, and after exclusion of articles that did not meet the eligibility criteria, 86 articles were included in this systematic review. In the 86 included studies, 3927 lncRNAs were differentially expressed between cases and controls. Among these, 110 lncRNAs were reported as being altered in samples from at least 2 studies and only 16 of them in ≥ ۳ studies, which were selected for further evaluation. Of these, 12 lncRNAs were consistently dysregulated between cases and controls (CCAT1, CCDC26, CRNDE, HOTAIR, KCNQ5IT1, LINC00265, MALAT1, PVT1, SNHG5,TUG1: increased in cases, MEG3 and NEAT1: decreased in cases) in human samples of patients with some type of leukemia. Conclusion: Our data demonstrate that 12 lncRNAs are dysregulated in leukemia.

Introduction

Leukemia is a type of cancer that affects the blood and bone marrow and is characterized by the uncontrolled production and accumulation of blood cells (1). According to American Cancer Society (2), cancer the second leading cause of deaths among children, adolescents and young adults younger than 20 years, and leukemia is the main type of cancer that affect children. In addition, 381,774 people are living with or in remission from leukemia in the US (2). Radiation exposure, viral infections, ethnicity, gender and genetic mutations are some of the risk factors of leukemia (1). However, more studies are necessary to better understand the development and the pathogenesis of the different types of leukemia. In this context, epigenetic factors, such as non-coding RNAs (ncRNA), have been associated with leukemia development. NcRNAs are a group of regulatory RNAs that are not translated into protein (3). NcRNAs longer than 200 nucleotides are classified as long non-coding RNAs (lncRNAs). LncRNAs are located in nucleus, where they can act as molecular scaffolds, help in alternative splicing or modify chromatin structures. In addition, there are some lncRNAs that have functions in cytoplasm, such as modulating translation, promoting or inhibiting mRNA degradation, and acting as miRNAs sponges (4).