The relapse and resistance to cytarabine (Ara-C) therapy is still a dominating obstacle to the successful clinical treatment of acute myeloid leukemia (AML). Recent studies have shown that dysregulation of miRNAs might modulate the resistance of cancer cells to anticancer drugs; yet, the mechanism is not fully understood. In this study, we showed a significant downregulation of miR-134 in human multidrug-resistant leukemia cells and relapsed/refractory AML patient samples. Overexpression of miR-134 sensitized K562/A02 and HL-60/ADM cells to Ara-C, inhibited cell colony formation, and enhanced the ability of Ara-C to induce apoptosis. Mechanistic analyses revealed that Mnks was a putative target of miR-134, which was inversely correlated with miR-134 expression in human multidrug-resistant leukemia cells and relapsed/refractory AML patient samples. Further investigation showed that miR-134 increased the anti-tumor effects of Ara-C through inhibiting phosphorylation of eukaryotic initiation factor 4E and downregulating Mcl-1 and bcl2, which was independent of p38 and Erk1/2 activation. Taken together, our results demonstrate that miR-134 plays a pivotal role in AML Ara-C resistance through increasing cell sensitivity to Ara-C and promoting apoptosis by targeting Mnks.
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http://dx.doi.org/10.2147/OTT.S143465 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Department of Signaling and Gene Expression, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037.
is one of the three most frequently mutated genes in age-related clonal hematopoiesis (CH), alongside and (. CH can progress to myeloid malignancies including chronic monomyelocytic leukemia (CMML) and is also strongly associated with inflammatory cardiovascular disease and all-cause mortality in humans. DNMT3A and TET2 regulate DNA methylation and demethylation pathways, respectively, and loss-of-function mutations in these genes reduce DNA methylation in heterochromatin, allowing derepression of silenced elements in heterochromatin.
View Article and Find Full Text PDFDalton Trans
January 2025
Department of Chemistry, Faculty of Science, Cairo University, Gamma Street, Giza, Cairo 12613, Egypt.
The photo-induced CO-releasing properties of the dark-stable complex [RuCl(CO)L] (L = 2-(pyridin-2-yl)quinoxaline) were investigated under 468 nm light exposure in the presence and absence of biomolecules such as histidine, calf thymus DNA and hen egg white lysozyme. The CO release kinetics were consistent regardless of the presence of these biomolecules, suggesting that they did not influence the CO release mechanism. The quinoxaline ligand demonstrated exceptional cytotoxicity against human acute monocytic leukemia cells (THP-1), with evidence of potential DNA damage ascertained by comet assay, while it remained non-toxic to normal kidney epithelial cells derived from African green monkey (Vero) cell lines.
View Article and Find Full Text PDFCancer Immunol Immunother
January 2025
Department of Otorhinolaryngology-Head and Neck Surgery, The Second Affiliated Hospital of Harbin Medical University, No. 246 Xuefu Road, Nangang District, Harbin, 150001, Heilongjiang Province, China.
Background: Tumor-derived small extracellular vesicles (sEVs) play an essential role in reprogramming the tumor microenvironment. Metabolic reprogramming is an essential prerequisite for M2 polarization of tumor-associated macrophages (TAMs). This M2 phenotype is closely related to the immune dysfunction of CD8 T cells and subsequent tumor progression.
View Article and Find Full Text PDFAm J Dermatopathol
December 2024
Department of Dermatology, Columbia University, New York, NY.
Acute myeloid leukemia is a cancer involving uncontrolled proliferation of hematopoietic cells. Cutaneous involvement is referred to as leukemia cutis (LC). The histopathologic presentation of LC is variable, and may present with perivascular, periadnexal, dermal, or subcutaneous infiltrate.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Medical University of South Carolina, Charleston, SC, USA.
Background: Alzheimer's disease (AD) is associated with cognitive impairment and neuro-inflammation. Dysregulated activation of microglia and astrocytes induces neuro-inflammation, and reactive astrocytes have been classified into A1 neurotoxic and A2 neuroprotective phenotypes. A1 astrocytes are induced by activated neuro-inflammatory microglia via secreting IL-1α, TNFα and C1q, and contributing to inflammation and neuronal cell death.
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