Acute promyelocytic leukemia with trisomy 8 showing normal PML-RARA FISH signal patterns: diagnostic application of long-distance polymerase chain reaction in molecularly discrepant leukemia cases

Inducing cell proliferative prevention in human acute promyelocytic leukemia by miR-182 inhibition through modulation of CASP9 expression

MicroRNAs (miRNAs) are one class of endogenous non-coding RNAs that involved in post-transcriptional regulation of the gene. MiRNAs through interaction with messenger RNA (mRNA) involved in several biological processes such as cell cycle, differentiation, growth, metabolism, aging and apoptosis. MiRNAs may act as an oncogene or a tumor suppressor via up or down regulation in cancerous cells. MiR-182 located in a miR-183/-96/-182 cluster, this is the highly conserved cluster to have an important role in cancer development and tumorigenesis. Abnormal expression of miR-182 in a variety of human cancers has reported. Oncogenic features of miR-182 confirmed through negative regulation of various tumor suppressor genes. In this study, miR-182 inhibition in acute promyelocytic leukemia (APL) cell line (HL60) was performed by locked nucleic acid (LNA) anti-miR. MTT assay in three-time points 24, 48 and 72h after LNA-anti-miR-182 transfection was performed. Our study demonstrated inhibition of miR-182 can expansively decrease cell proliferation of APL cells. The Western blotting analysis presents that CASP9 expression associated with inhibition of miR-182. CASP9 protein has an important role in the mitochondrial cell death pathway as the initiator of apoptosis. These results can offer a way for inhibition of APL cells proliferates and produce translational medicine based on microgenomics and antisense therapy.

Inhibition of microRNA miR-92a induces apoptosis and inhibits cell proliferation in human acute promyelocytic leukemia through modulation of p63 expression

MicroRNAs (miRNAs) are endogenous non-coding RNAs, 19-25 nucleotides in length involved in post-transcriptional regulation of gene expression of great majority of the human protein coding genes. Different aspects of cellular activities like cell growth, proliferation, and differentiation are regulated by miRNAs through their interaction with particular RNA species. In many tumors up or down-regulation of different miRNAs has been reported. Human miR-17-92 gene cluster is located on 13q31.3, rooming several miRNAs including miR-17-5p, miR-17-3p, miR-18, miR-19a, miR-20a and miR-92a. Amplification or overexpression of this cluster has been reported in acute myeloid leukemia, acute lymphoblastic leukemia and several other cancer types. Here, we performed inhibition of miR-92a in an acute promyelocytic leukemia (APL) cell line (HL-60) using locked nucleic acid (LNA) antagomir. In different time points after LNA-anti-miR92a transfection, MTT assay and annexin/propidium iodide staining were performed. These assessments indicate that miR-92a inhibition can extensively decrease the viability of these cells which is mainly due to induction of apoptosis. Western blot analysis of p63 protein also revealed that miR-92a inhibition resulted in p63 expression, hence activation of cellular pathways which are normally controlled by p63 protein are retrieved. These findings could open up a path to the miRNAs based therapeutic approach for treatment of APL.