MicroRNA in leukemia: Tumor suppressors and oncogenes with prognostic potential

Abstract

Leukemia is known as a progressive malignant disease, which destroys the blood‐forming organs and results in adverse effects on the proliferation and development of leukocytes and their precursors in the blood and bone marrow. There are four main classes of leukemia including acute leukemia, chronic leukemia, myelogenous leukemia, and lymphocytic leukemia. Given that a variety of internal and external factors could be associated with the initiation and progression of different types of leukemia. One of the important factors is epigenetic regulators such as microRNAs (miRNAs) and long noncoding RNAs (ncRNA). MiRNAs are short ncRNAs which act as tumor suppressor (i.e., miR‐15, miR‐16, let‐7, and miR‐127) or oncogene (i.e., miR‐155, miR‐17‐92, miR‐21, miR‐125b, miR‐93, miR‐143‐p3, miR‐196b, and miR‐223) in leukemia. It has been shown that deregulation of these molecules are associated with the initiation and progression of leukemia. Hence, miRNAs could be used as potential therapeutic candidates in the treatment of patients with leukemia. Moreover, increasing evidence revealed that miRNAs could be used as diagnostic and prognostic biomarkers in monitoring patients in early stages of disease or after received chemotherapy regimen. It seems that identification and development of new miRNAs could pave to the way to the development new therapeutic platforms for patients with leukemia. Here, we summarized various miRNAs as tumor suppressor and oncogene which could be introduced as therapeutic targets in treatment of leukemia.

Alteration in miRNAs expression in paediatric acute lymphocyticleukaemia: Insight into patients' therapeutic response

“…8 The meta-analysis of Rashed et al 52 pointed out that miR-24 could be used as a diagnostic discriminatory biomarker between ALL and AML as it is expressed at lower levels in ALL compared to AML. Our results refer to a significant increase in miR- 24 and Zhang et al 37 reported a low expression of miR-24 with newly diagnosed childhood ALL. It was reported that overexpression of miR-24 promotes myelopoiesis and inhibits B lymphopoiesis in haematopoietic progenitors 17,54 and during adult blood development.…”

“…By promoting proliferation, invasion and inhibiting apoptosis, miR‐21 is considered as a common oncomiR that modulates the expression of multiple cancer‐related target genes 22,23 . Aberrant expression of oncomiRs (miR‐21) was reported to promote leukaemogenesis through elevating the leukaemic stem/progenitor cell population, promoting cell proliferation, blocking cell differentiation, and lessening cell apoptosis 24 . In our study, we recorded a significant increase in miR‐21 expression level in paediatric ALL patients especially B‐cell lineages.…”

MicroRNA‐26a‐5p inhibits breast cancer cell growth by suppressing RNF6 expression

“…Therefore, the relationship between miRNAs and tumors is becoming a hotspot of current research . If the target gene of the miRNA is an oncogene, and the expression of miRNA is below normal level, it will lead to the increase of protein encoded by the oncogene and thus promotes the occurrence of tumors . In contrast, if the target gene of the miRNA is a tumor suppressor, and the expression of miRNA is higher than normal level, it will lead to the decrease of the tumor suppressor and also induces the occurrence of tumors .…”

“…If the target gene of the miRNA is an oncogene, and the expression of miRNA is below normal level, it will lead to the increase of protein encoded by the oncogene and thus promotes the occurrence of tumors . In contrast, if the target gene of the miRNA is a tumor suppressor, and the expression of miRNA is higher than normal level, it will lead to the decrease of the tumor suppressor and also induces the occurrence of tumors . Because one miRNA can regulate the expression of many oncogenes or tumor suppressor genes, using miRNA as a therapeutic target may be more effective than using a single oncogene or tumor suppressor gene as a therapeutic target .…”

Clinical Significance of MicroRNA-155 Regulated Autophagy and Apoptosis by targeting gene Rictor/Fos in Gastric Cancer Progression

“…Previous studies have found that microRNA-155 is abnormally expressed in various tumors and plays a centrol role in the process of tumor initiation, progression, invasion, and metastasis [29][30][31][32][33][34][35] . Our results indicated that expression of microRNA-155 can be up-regulated in some patients of gastric cancer and down-regulated in others.…”