Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

MicroRNAs (miRNAs) are small non-coding RNA molecules that are widely involved in cancer-related processes. The microRNA-21 (miR-21) has been identified as the only miRNA overexpressed in a variety of cancers, including leukemia. However, the function of miR-21 is yet unknown in chronic myelogenous leukemia (CML). Antisense oligonucleotides (ASOs), as inhibitors of miRNAs, have already been applied to therapeutic development and functional identification in miRNA research. In this study, we found that the antisense inhibition of miR-21 in K562 cells suppressed cell migration, promoted cell apoptosis, and inhibited cell growth, and up-regulated the expression of the tumor suppressor gene PDCD4. Meanwhile, pre-miRNA-21 increased migration and decreased cell apoptosis without affecting proliferation. We also validated that PDCD4 is a functional target of miR-21 in K562 cells. These effects of miR-21 might be partially due to its regulation of PDCD4. Our data suggest that miR-21 may play an oncogenic role in the cellular processes of CML, and antisense inhibition of miR-21 may therefore be useful as CML therapy.
 ...
PMID:Antisense oligonucleotide against miR-21 inhibits migration and induces apoptosis in leukemic K562 cells. 2706 29

Arsenic trioxide (ATO), an ancient traditional Chinese medicine, has been successfully used as a therapeutic agent for leukemia. Drug resistance and toxicity are major concerns with the treatment. MicroRNAs (miRNAs) are endogenous small non-coding RNA molecules that might modulate cellular sensitivity to anticancer drugs. miRNA-21 (miR-21) is one of the most prominent miRNAs involved in various aspects of human cancers. However, miR-21 has been rarely characterized in chronic myelogenous leukemia (CML). Here, we used a specific anti-miR-21 oligonucleotide (AMO-miR-21) to sensitize K562 cells to ATO by degradation of miR-21. The results showed that both AMO-miR-21 and ATO caused growth inhibition, apoptosis, and G1-phase arrest in K562 cells. Meanwhile, AMO-miR-21 significantly promoted ATO-mediated growth inhibition and apotosis without affecting the G1 phase. Apoptotic cells were confirmed morphologically with Giemsa's staining. Furthermore, dual-luciferase reporter vector, containing two tandem miR-21 binding sites from PDCD4 3'UTR, validated that PDCD4 was directly regulated by miR-21. Therefore, AMO-miR-21 sensitized leukemic K562 cells to ATO by inducing apoptosis partially due to its up-regulation of PDCD4 protein level. The combination of ATO and AMO-miR-21 present therapeutic potential for CML.
 ...
PMID:Anti-miR-21 oligonucleotide sensitizes leukemic K562 cells to arsenic trioxide by inducing apoptosis. 2014 95

Chronic myeloid leukemia in the blastic phase (CML-BP) responds poorly to clinical treatments and is usually fatal. In this study, we found that the histone H3 lysine 4 (H3K4) demethylase RBP2 (also called JARID1A and KDM5A) is underexpressed in CML-BP. The RBP2 histone demethylase stimulates leukemia cell differentiation and inhibits cell proliferation. We identified miR-21 was directly downregulated by RBP2 and found that miR-21 downregulated PDCD4 expression in leukemia cells. By binding to miR-21 promoter and by demethylating of trimethylated H3K4 at the miR-21 locus, RBP2 downregulated miR-21 expression. This in turn activated PDCD4. In conclusion, RBP2 epigenetically downregulated miR-21 in blast transformation of CML.
...
PMID:Histone demethylase RBP2 decreases miR-21 in blast crisis of chronic myeloid leukemia. 2557 17

MicroRNAs (miRNAs) are regulators of several key patho-physiological processes, including cell cycle and apoptosis. Using microarray-based miRNA profiling in K562 cells, a model of chronic myeloid leukemia (CML), we found that the oncoprotein BCR-ABL1 regulates the expression of miR-21, an "onco-microRNA", found to be overexpressed in several cancers. This effect relies on the presence of two STAT binding sites on the promoter of miR-21, and on the phosphorylation status of STAT5, a transcription factor activated by the kinase activity of BCR-ABL1. Mir-21 regulates the expression of PDCD4 (programmed cell death protein 4), a tumor suppressor identified through a proteomics approach. The phosphoSTAT5 - miR-21 - PDCD4 pathway was active in CML primary CD34+ cells, but also in acute myeloid leukemia (AML) models like MV4.11 and MOLM13, where the constitutively active tyrosine kinase FLT3-ITD plays a similar role to BCR-ABL1 in the K562 cell line.
 ...
PMID:A tyrosine kinase-STAT5-miR21-PDCD4 regulatory axis in chronic and acute myeloid leukemia cells. 2910 Mar 2