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Science (New York, N.Y.) Jul 2023Ribosomes catalyze protein synthesis by cycling through various functional states. These states have been extensively characterized in vitro, but their distribution in...
Ribosomes catalyze protein synthesis by cycling through various functional states. These states have been extensively characterized in vitro, but their distribution in actively translating human cells remains elusive. We used a cryo-electron tomography-based approach and resolved ribosome structures inside human cells with high resolution. These structures revealed the distribution of functional states of the elongation cycle, a Z transfer RNA binding site, and the dynamics of ribosome expansion segments. Ribosome structures from cells treated with Homoharringtonine, a drug used against chronic myeloid leukemia, revealed how translation dynamics were altered in situ and resolve the small molecules within the active site of the ribosome. Thus, structural dynamics and drug effects can be assessed at high resolution within human cells.
Topics: Humans; Antineoplastic Agents; Binding Sites; Cryoelectron Microscopy; Neoplasms; Protein Biosynthesis; Ribosomes; RNA, Transfer
PubMed: 37410833
DOI: 10.1126/science.adh1411 -
Nature Communications Oct 2023Tumor growth requires elevated ribosome biogenesis. Targeting ribosomes is an important strategy for cancer therapy. The ribosome inhibitor, homoharringtonine (HHT), is...
Tumor growth requires elevated ribosome biogenesis. Targeting ribosomes is an important strategy for cancer therapy. The ribosome inhibitor, homoharringtonine (HHT), is used for the clinical treatment of leukemia, yet it is ineffective for the treatment of solid tumors, the reasons for which remain unclear. Here we show that Snail1, a key factor in the regulation of epithelial-to-mesenchymal transition, plays a pivotal role in cellular surveillance response upon ribotoxic stress. Mechanistically, ribotoxic stress activates the JNK-USP36 signaling to stabilize Snail1 in the nucleolus, which facilitates ribosome biogenesis and tumor cell survival. Furthermore, we show that HHT activates the JNK-USP36-Snail1 axis in solid tumor cells, but not in leukemia cells, resulting in solid tumor cell resistance to HHT. Importantly, a combination of HHT with the inhibition of the JNK-USP36-Snail1 axis synergistically inhibits solid tumor growth. Together, this study provides a rationale for targeting the JNK-USP36-Snail1 axis in ribosome inhibition-based solid tumor therapy.
Topics: Humans; Cell Survival; Ribosomes; Cell Nucleolus; Neoplasms; Leukemia; Ubiquitin Thiolesterase
PubMed: 37833415
DOI: 10.1038/s41467-023-42257-8 -
American Journal of Hematology Oct 2023Patients with chronic myeloid leukemia (CML) and T315I mutation generally have a poor prognosis. Their outcome in the post-ponatinib era remains unclear. We reviewed...
Patients with chronic myeloid leukemia (CML) and T315I mutation generally have a poor prognosis. Their outcome in the post-ponatinib era remains unclear. We reviewed patients with CML in chronic (CP) or accelerated phase (AP) who developed a T315I mutation between March 15, 2004, and July 26, 2022. Patients were divided into CP, AP, or blastic phase (BP) at the time of mutation detection. Overall survival (OS) was defined from the time of mutation detection to the date of death or last follow-up. We identified a total of 107 patients: 54 (51%) in CP, 14 (13%) in AP, and 39 (36%) in BP. One hundred and two patients received subsequent therapy after the T315I mutation was detected. At a median follow-up of 75 months (95% CI, 41-110), the median OS was 49 months (95% CI, 26-73) and the 5-year OS rate was 44%. Patients who were in CML-CP at the time of mutation detection had better survival compared with those in AP or BP, with a median OS of 132, 31, and 6 months, and 5-year OS rates of 70%, 37%, and 10%, respectively (p < .001). Patients with CML-CP treated with ponatinib and/or asciminib had a 5-year OS of 77% compared with 50% in those who received other treatments (chemotherapy, second-generation tyrosine kinase inhibitors, homoharringtonine, and investigational drugs) (p = .14). In summary, patients with CML-CP at the time of T315I mutation detection may have a relatively indolent disease course with a long-term OS of 70%. Treatment with third-generation tyrosine kinase inhibitors seemed to improve survival in patients with CML-CP.
Topics: Humans; Drug Resistance, Neoplasm; Fusion Proteins, bcr-abl; Imidazoles; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Mutation; Protein Kinase Inhibitors; Pyridazines
PubMed: 37485584
DOI: 10.1002/ajh.27037 -
Journal of Clinical Oncology : Official... Nov 2023Homoharringtonine (HHT) is commonly used for the treatment of Chinese adult AML, and all-trans retinoic acid (ATRA) has been verified in acute promyelocytic leukemia... (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
Homoharringtonine (HHT) is commonly used for the treatment of Chinese adult AML, and all-trans retinoic acid (ATRA) has been verified in acute promyelocytic leukemia (APL). However, the efficacy and safety of HHT-based induction therapy have not been confirmed for childhood AML, and ATRA-based treatment has not been evaluated among patients with non-APL AML.
PATIENTS AND METHODS
This open-label, multicenter, randomized Chinese Children's Leukemia Group-AML 2015 study was performed across 35 centers in China. Patients with newly diagnosed childhood AML were first randomly assigned to receive an HHT-based (H arm) or etoposide-based (E arm) induction regimen and then randomly allocated to receive cytarabine-based (AC arm) or ATRA-based (AT arm) maintenance therapy. The primary end points were the complete remission (CR) rate after induction therapy, and the secondary end points were the overall survival (OS) and event-free survival (EFS) at 3 years.
RESULTS
We enrolled 1,258 patients, of whom 1,253 were included in the intent-to-treat analysis. The overall CR rate was significantly higher in the H arm than in the E arm (79.9% 73.9%, = .014). According to the intention-to-treat analysis, the 3-year OS was 69.2% (95% CI, 65.1 to 72.9) in the H arm and 62.8% (95% CI, 58.7 to 66.6) in the E arm ( = .025); the 3-year EFS was 61.1% (95% CI, 56.8 to 65.0) in the H arm and 53.4% (95% CI, 49.2 to 57.3) in the E arm ( = .022). Among the per-protocol population, who received maintenance therapy, the 3-year EFS did not differ significantly across the four arms (H + AT arm: 70.7%, 95% CI, 61.1 to 78.3; H + AC arm: 74.8%, 95% CI, 67.0 to 81.0, = .933; E + AC arm: 72.9%, 95% CI, 65.1 to 79.2, = .789; E + AT arm: 66.2%, 95% CI, 56.8 to 74.0, = .336).
CONCLUSION
HHT is an alternative combination regimen for childhood AML. The effects of ATRA-based maintenance are comparable with those of cytarabine-based maintenance therapy.
Topics: Child; Humans; Antineoplastic Combined Chemotherapy Protocols; Cytarabine; East Asian People; Homoharringtonine; Leukemia, Promyelocytic, Acute; Multicenter Studies as Topic; Remission Induction; Survival Rate; Treatment Outcome; Tretinoin
PubMed: 37531592
DOI: 10.1200/JCO.22.02836 -
Cellular Signalling Sep 2023High-risk neuroblastoma (NB) is a heterogeneous and malignant childhood cancer that is frequently characterized by MYCN proto-oncogene amplification or elevated N-Myc...
High-risk neuroblastoma (NB) is a heterogeneous and malignant childhood cancer that is frequently characterized by MYCN proto-oncogene amplification or elevated N-Myc protein (N-Myc) expression. An N-Myc downstream target gene, insulinoma associated-1 (INSM1) has emerged as a biomarker that plays a critical role in facilitating NB tumor cell growth and transformation. N-Myc activates endogenous INSM1 gene expression through binding to the E2-box of the INSM1 proximal promoter in NB. We identified a plant alkaloid, homoharringtonine (HHT), from a chemical library screening showing potent inhibition of INSM1 promoter activity. This positive-hit plant alkaloid exemplifies an effective screening approach for repurposed compound targeting INSM1 expression in NB cancer therapy. The elevated N-Myc and INSM1 expression in NB constitutes a positive-loop through INSM1 activation that promotes N-Myc stability. In the present study, the biological effects and anti-tumor properties of HHT against NB were examined. HHT either down regulates and/or interferes with the binding of N-Myc to the E2-box of the INSM1 promoter and the inhibition of PI3K/AKT-mediated N-Myc stability could lead to the NB cell apoptosis. HHT inhibition of NB cell proliferation is consistent with the INSM1 expression as higher level of INSM1 exhibits a more sensitive IC value. The combination treatment of HHT and A674563 provides a better option of increasing potency and reducing cellular cytotoxicity than HHT or A674563 treatment alone. Taken together, the suppression of the INSM1-associated signaling pathway axis promotes the inhibition of NB tumor cell growth. This study developed a feasible approach for repurposing an effective anti-NB drug.
Topics: Humans; Child; Homoharringtonine; Insulinoma; Phosphatidylinositol 3-Kinases; Drug Repositioning; Cell Line, Tumor; Neuroblastoma; Pancreatic Neoplasms; Gene Expression Regulation, Neoplastic; Repressor Proteins
PubMed: 37301315
DOI: 10.1016/j.cellsig.2023.110753 -
Science Advances Apr 2024Histopathological heterogeneity is a hallmark of prostate cancer (PCa). Using spatial and parallel single-nucleus transcriptomics, we report an androgen receptor...
Histopathological heterogeneity is a hallmark of prostate cancer (PCa). Using spatial and parallel single-nucleus transcriptomics, we report an androgen receptor (AR)-positive but neuroendocrine-null primary PCa subtype with morphologic and molecular characteristics of small cell carcinoma. Such small cell-like PCa (SCLPC) is clinically aggressive with low AR, but high stemness and proliferation, activity. Molecular characterization prioritizes protein translation, represented by up-regulation of many ribosomal protein genes, and SP1, a transcriptional factor that drives SCLPC phenotype and overexpresses in castration-resistant PCa (CRPC), as two potential therapeutic targets in AR-indifferent CRPC. An SP1-specific inhibitor, plicamycin, effectively suppresses CRPC growth in vivo. Homoharringtonine, a Food And Drug Administration-approved translation elongation inhibitor, impedes CRPC progression in preclinical models and patients with CRPC. We construct an SCLPC-specific signature capable of stratifying patients for drug selectivity. Our studies reveal the existence of SCLPC in admixed PCa pathology, which may mediate tumor relapse, and establish SP1 and translation elongation as actionable therapeutic targets for CRPC.
Topics: Male; Humans; Prostatic Neoplasms, Castration-Resistant; Receptors, Androgen; Neoplasm Recurrence, Local; Transcription Factors; Protein Biosynthesis; Cell Line, Tumor; Gene Expression Regulation, Neoplastic
PubMed: 38569039
DOI: 10.1126/sciadv.adm7098 -
The Journal of Pharmacy and Pharmacology Oct 2023Pancreatic cancer (PC) is a very lethal malignancy with a scarcity of treatment options. Although erlotinib- and gemcitabine-based treatments have been approved for PC,...
OBJECTIVES
Pancreatic cancer (PC) is a very lethal malignancy with a scarcity of treatment options. Although erlotinib- and gemcitabine-based treatments have been approved for PC, their effectiveness is limited. The present study is aimed at exploring the molecular and epigenetic mechanisms of anticancer activities of homoharringtonine (HHT) and its interaction with erlotinib to develop a potential therapeutic strategy for PC.
METHODS
The RT-qPCR, western blotting, immunofluorescence and expression-vectors and oligonucleotide transfection were employed to determine the expression characteristics of onco-factors. Anticancer activities were determined by MTT, colony forming, and flowcytometric analysis. Dual luciferase assay was conducted to confirm putative target of miR-130b-3p. In-vivo experiments were followed by immunohistochemical assay.
KEY FINDINGS
The EphB4/JAK2/STAT3 pathway drives the growth and proliferation of PC through induction of prosurvival factors and cell cycle mediators. HHT directly and epigenetically via miR-130b-3p targets EphB4, leading to downregulation of JAK2/STAT3 pathway. The inactivation of STAT3 results in diminution of antiapoptotic factors and cell cycle mediators. HHT also enhances the anticancer activity of erlotinib.
CONCLUSIONS
HHT demonstrates potential anticancer activities in PC by downregulating EphB4/JAK2/STAT3 signalling. HHT also produces synergistic effects with erlotinib.
Topics: Humans; Homoharringtonine; MicroRNAs; Erlotinib Hydrochloride; Cell Line, Tumor; Pancreatic Neoplasms; Cell Proliferation; Janus Kinase 2; STAT3 Transcription Factor
PubMed: 37463100
DOI: 10.1093/jpp/rgad055 -
Blood Cancer Journal Feb 2024Germline, mono-allelic mutations in RUNX1 cause familial platelet disorder (RUNX1-FPD) that evolves into myeloid malignancy (FPD-MM): MDS or AML. FPD-MM commonly harbors...
Germline, mono-allelic mutations in RUNX1 cause familial platelet disorder (RUNX1-FPD) that evolves into myeloid malignancy (FPD-MM): MDS or AML. FPD-MM commonly harbors co-mutations in the second RUNX1 allele and/or other epigenetic regulators. Here we utilized patient-derived (PD) FPD-MM cells and established the first FPD-MM AML cell line (GMR-AML1). GMR-AML1 cells exhibited active super-enhancers of MYB, MYC, BCL2 and CDK6, augmented expressions of c-Myc, c-Myb, EVI1 and PLK1 and surface markers of AML stem cells. In longitudinally studied bone marrow cells from a patient at FPD-MM vs RUNX1-FPD state, we confirmed increased chromatin accessibility and mRNA expressions of MYB, MECOM and BCL2 in FPD-MM cells. GMR-AML1 and PD FPD-MM cells were sensitive to homoharringtonine (HHT or omacetaxine) or mebendazole-induced lethality, associated with repression of c-Myc, EVI1, PLK1, CDK6 and MCL1. Co-treatment with MB and the PLK1 inhibitor volasertib exerted synergistic in vitro lethality in GMR-AML1 cells. In luciferase-expressing GMR-AML1 xenograft model, MB, omacetaxine or volasertib monotherapy, or co-treatment with MB and volasertib, significantly reduced AML burden and improved survival in the immune-depleted mice. These findings highlight the molecular features of FPD-MM progression and demonstrate HHT, MB and/or volasertib as effective agents against cellular models of FPD-MM.
Topics: Humans; Animals; Mice; Core Binding Factor Alpha 2 Subunit; Leukemia, Myeloid, Acute; Homoharringtonine; Blood Platelets; Blood Platelet Disorders; Proto-Oncogene Proteins c-bcl-2
PubMed: 38316746
DOI: 10.1038/s41408-024-00981-4 -
Cancer Research May 2024Patients with triple-negative breast cancer (TNBC) have a poor prognosis due to the lack of effective molecular targets for therapeutic intervention. Here we found that...
UNLABELLED
Patients with triple-negative breast cancer (TNBC) have a poor prognosis due to the lack of effective molecular targets for therapeutic intervention. Here we found that the long noncoding RNA (lncRNA) MILIP supports TNBC cell survival, proliferation, and tumorigenicity by complexing with transfer RNAs (tRNA) to promote protein production, thus representing a potential therapeutic target in TNBC. MILIP was expressed at high levels in TNBC cells that commonly harbor loss-of-function mutations of the tumor suppressor p53, and MILIP silencing suppressed TNBC cell viability and xenograft growth, indicating that MILIP functions distinctively in TNBC beyond its established role in repressing p53 in other types of cancers. Mechanistic investigations revealed that MILIP interacted with eukaryotic translation elongation factor 1 alpha 1 (eEF1α1) and formed an RNA-RNA duplex with the type II tRNAs tRNALeu and tRNASer through their variable loops, which facilitated the binding of eEF1α1 to these tRNAs. Disrupting the interaction between MILIP and eEF1α1 or tRNAs diminished protein synthesis and cell viability. Targeting MILIP inhibited TNBC growth and cooperated with the clinically available protein synthesis inhibitor omacetaxine mepesuccinate in vivo. Collectively, these results identify MILIP as an RNA translation elongation factor that promotes protein production in TNBC cells and reveal the therapeutic potential of targeting MILIP, alone and in combination with other types of protein synthesis inhibitors, for TNBC treatment.
SIGNIFICANCE
LncRNA MILIP plays a key role in supporting protein production in TNBC by forming complexes with tRNAs and eEF1α1, which confers sensitivity to combined MILIP targeting and protein synthesis inhibitors.
Topics: Triple Negative Breast Neoplasms; Humans; Female; RNA, Transfer; Animals; Mice; Peptide Elongation Factor 1; RNA, Long Noncoding; Cell Proliferation; Protein Biosynthesis; Cell Line, Tumor; Xenograft Model Antitumor Assays; Mice, Nude; Gene Expression Regulation, Neoplastic
PubMed: 38593213
DOI: 10.1158/0008-5472.CAN-23-3046 -
Biochimica Et Biophysica Acta.... Jan 2024Acute myeloid leukemia (AML) presents ongoing therapeutic challenges due to its intricate molecular pathogenesis. This study aimed to elucidate the role of RNA binding...
BACKGROUND
Acute myeloid leukemia (AML) presents ongoing therapeutic challenges due to its intricate molecular pathogenesis. This study aimed to elucidate the role of RNA binding motif protein 39 (RBM39) in AML cell proliferation, apoptosis, and chemosensitivity, and its potential modulation of the PI3K/AKT pathway.
METHODS
In vitro and in vivo experiments were conducted using AML cell lines (K562 and U937) and bone marrow mononuclear cells (BM-MNCs) from AML patients and healthy donors. RBM39 mRNA and protein levels were measured using qRT-PCR and Western blotting. Cells were transfected with sh-RBM39 or sh-control, and then treated with daunorubicin (DNR) or homoharringtonine (HHT) at varied concentrations. Cell proliferation, chemosensitivity, and apoptosis were assessed through CCK-8 assay and Annexin V-APC/PI staining. RNA sequencing identified differentially expressed genes (DEGs) post RBM39 knockdown. An in vivo xenograft AML model using E7070, a selective RBM39 inhibitor, was employed to evaluate RBM39 modulation effects.
RESULTS
Elevated RBM39 levels were found in AML patients and cell lines compared to controls. RBM39 knockdown promoted apoptosis, curtailed cell proliferation, and enhanced chemosensitivity to DNR and HHT in vitro. Drug-resistant or relapsed AML patients displayed higher RBM39 levels. RNA sequencing after RBM39 knockdown revealed downregulated PI3K/AKT signaling. The xenograft model validated in vitro results, as E7070 treatment suppressed AML xenograft growth via RBM39-mediated PI3K/AKT pathway suppression.
CONCLUSION
RBM39 plays a pivotal role in AML progression through the PI3K/AKT signaling pathway. Targeting RBM39, potentially with E7070, could inhibit proliferation and induce apoptosis in AML cells, offering a promising avenue for future AML research and treatment.
Topics: Humans; Proto-Oncogene Proteins c-akt; Phosphatidylinositol 3-Kinases; Cell Line, Tumor; Leukemia, Myeloid, Acute; Daunorubicin
PubMed: 37852323
DOI: 10.1016/j.bbamcr.2023.119607