Minnelide exhibits antileukemic activity by targeting the Ars2/miR-190a-3p axis.

BACKGROUND: The identification of a novel and effective strategy for the clinical treatment of acute leukemia (AL) is a long-term goal. Minnelide, a water-soluble prodrug of triptolide, has recently been evaluated in phase I and II clinical trials in patients with multiple cancers and has shown promise as an antileukemic agent. However, the molecular mechanism underlying minnelide's antileukemic activity remains unclear. PURPOSE: To explore the molecular mechanisms by which minnelide exhibits antileukemic activity. METHODS: AL cells, primary human leukemia cells, and a xenograft mouse model were treated with triptolide and minnelide. The molecular mechanism was elucidated using western blotting, immunoprecipitation, flow cytometry, GSEA and liquid chromatography-mass spectrometry analysis. RESULTS: Minnelide was highly effective in inhibiting leukemogenesis and improving survival in two complementary AL mouse models. Triptolide, an active form of minnelide, causes cell cycle arrest in G1 phase and induces apoptosis in both human AL cell lines and primary AL cells. Mechanistically, we identified Ars2 as a new chemotherapeutic target of minnelide for AL treatment. We found that triptolide directly targeted Ars2, resulting in the downregulation of miR-190a-3p, which led to the disturbance of PTEN/Akt signaling and culminated in G1 cell cycle arrest and apoptosis. CONCLUSIONS: Our findings demonstrate that targeting Ars2/miR-190a-3p signaling using minnelide could represent a novel chemotherapeutic strategy for AL treatment and support the evaluation of minnelide for the treatment of AL in clinical trials.

Targeting PI4KA sensitizes refractory leukemia to chemotherapy by modulating the ERK/AMPK/OXPHOS axis.

Background: The emergence of chemoresistance in leukemia markedly impedes chemotherapeutic efficacy and dictates poor prognosis. Recent evidence has revealed that phosphatidylinositol 4 kinase-IIIα (PI4KA) plays a critical role in tumorigenesis. However, the molecular mechanisms of PI4KA-regulated chemoresistance and leukemogenesis remain largely unknown. Methods: Liquid chromatography-mass spectrometry (LC-MS), patient samples and leukemia xenograft mouse models were used to investigate whether PI4KA was an effective target to overcome chemoresistance in leukemia. Enzyme-linked immunosorbent assay (ELISA) and molecular mechanics/generalized born surface area (MM/GBSA) method were employed to identify cepharanthine (CEP) as a novel PI4KA inhibitor. Results: High expression of PI4KA was observed in drug-resistant leukemia cells or in relapsed leukemia patients, which was correlated with poor overall survival. Depletion of PI4KA sensitized drug-resistant leukemia cells to chemotherapeutic drugs in vitro and in vivo by regulating ERK/AMPK/OXPHOS axis. We also identified cepharanthine (CEP) as a novel PI4KA inhibitor, which could undermine the stability of the PI4KA/TTC7/FAM126 complex, enhancing the sensitivity of drug-resistant leukemia cells to chemotherapeutic drugs in vitro and in vivo. Conclusions: Our study underscored the potential of therapeutic targeting of PI4KA to overcome chemoresistance in leukemia. A combination of the PI4KA inhibitor with classic chemotherapeutic agents could represent a novel therapeutic strategy for the treatment of refractory leukemia.

Type 1 Diabetes Mellitus-Related circRNAs Regulate CD4+ T Cell Functions.

Circular RNAs (circRNAs) participate in development of malignancies through its active role as a "miRNA sponge." Their roles in type 1 diabetes mellitus (T1DM) pathogenesis are elusive. Here, the important role of circRNAs in T1DM was explored. circRNA profiling was performed for isolated CD4+ T cells from blood of T1DM and healthy volunteers. There were 257 differentially expressed circRNAs. Only three upregulated DEcircRNAs (hsa_circ_0000324, hsa_circ_0001853, and hsa_circ_0068797) were consistent with the GEO database. Through KEGG analyses, it was found that the three DEcircRNAs were associated with 11 miRNAs and 8 immune-related target genes (mRNA). Further analysis found that four miRNAs, two circRNAs, and four mRNAs were associated with nine circRNA-miRNA-mRNA networks. This confirmed the requirements of sponge mechanisms. The qRT-PCR analysis revealed that circRNA000324/miRNA675-5p/MAPK14 and circRNA000324/miRNA-675-5p/SYK may be potential mechanisms in regulation of differentiation and proliferation of CD4+ T cell in patients with T1DM. Therefore, targeting circRNA to regulate cellular immune responses by regulating CD4+ T cell differentiation may be a new strategy for the treatment of T1DM.

Cepharanthine sensitizes human triple negative breast cancer cells to chemotherapeutic agent epirubicin via inducing cofilin oxidation-mediated mitochondrial fission and apoptosis.

Inhibition of autophagy has been accepted as a promising therapeutic strategy in cancer, but its clinical application is hindered by lack of effective and specific autophagy inhibitors. We previously identified cepharanthine (CEP) as a novel autophagy inhibitor, which inhibited autophagy/mitophagy through blockage of autophagosome-lysosome fusion in human breast cancer cells. In this study we investigated whether and how inhibition of autophagy/mitophagy by cepharanthine affected the efficacy of chemotherapeutic agent epirubicin in triple negative breast cancer (TNBC) cells in vitro and in vivo. In human breast cancer MDA-MB-231 and BT549 cells, application of CEP (2 µM) greatly enhanced cepharanthine-induced inhibition on cell viability and colony formation. CEP interacted with epirubicin synergistically to induce apoptosis in TNBC cells via the mitochondrial pathway. We demonstrated that co-administration of CEP and epirubicin induced mitochondrial fission in MDA-MB-231 cells, and the production of mitochondrial superoxide was correlated with mitochondrial fission and apoptosis induced by the combination. Moreover, we revealed that co-administration of CEP and epirubicin markedly increased the generation of mitochondrial superoxide, resulting in oxidation of the actin-remodeling protein cofilin, which promoted formation of an intramolecular disulfide bridge between Cys39 and Cys80 as well as Ser3 dephosphorylation, leading to mitochondria translocation of cofilin, thus causing mitochondrial fission and apoptosis. Finally, in mice bearing MDA-MB-231 cell xenografts, co-administration of CEP (12 mg/kg, ip, once every other day for 36 days) greatly enhanced the therapeutic efficacy of epirubicin (2 mg/kg) as compared with administration of either drug alone. Taken together, our results implicate that a combination of cepharanthine with chemotherapeutic agents could represent a novel therapeutic strategy for the treatment of breast cancer.

Decoding the Mechanism of Shen Qi Sha Bai Decoction in Treating Acute Myeloid Leukemia Based on Network Pharmacology and Molecular Docking.

Traditional Chinese Medicine (TCM) has been shown to be efficacious in treating leukemia for thousands of years. It has been shown that Shen Qi Sha Bai Decoction (SQSBD) has been extensively used in the treatment of acute myeloid leukemia (AML). However, the mechanism of SQSBD in treating AML remains unclear. In this study, we employed network pharmacology to analyze the potential active components and elucidate molecular mechanism of SQSBD in treating AML. A total of 268 active components were identified from SQSBD, among which 9 key components (Quercetin, luteolin, kaempferol, licochalcone A, formononetin, wogonin, ß-sitosterol, oroxylin A, naringenin, and baicalein) were hit by the 6 hub targets (CDK1, MAPK1, JUN, PCNA, HSB1, STAT3) associated with leukemia. Molecular docking showed that two core active components, quercetin and licochalcone A, exhibited the highest component-like properties (DL), and could bind well to CDK1 and MAPK1 protein. The experimental validation of these two components showed that quercetin inhibited cell growth through CDK1 dephosphorylation-mediated cell cycle arrest at G2/M phase in human AML U937 and HL60 cells, and licochalcone A induced cell differentiation in these leukemia cells via activation of MAPK1 and upregulation of CD11b. All these results indicate that SQSBD is effective in the treatment of AML, and quercetin and licochalcone A are the major candidate compounds for AML treatment.