The Rap G protein signal regulates Notch activation in early thymic progenitor cells, and deregulated Rap activation (Rap(high)) results in the development of Notch-dependent T-cell acute lymphoblastic leukemia (T-ALL). We demonstrate that the Rap signal is required for the proliferation and leukemogenesis of established Notch-dependent T-ALL cell lines. Attenuation of the Rap signal by the expression of a dominant-negative Rap1A17 or Rap1GAP, Sipa1, in a T-ALL cell line resulted in the reduced Notch processing at site 2 due to impaired maturation of Adam10. Inhibition of the Rap1 prenylation with a geranylgeranyl transferase inhibitor abrogated its membrane-anchoring to Golgi-network and caused reduced proprotein convertase activity required for Adam10 maturation. Exogenous expression of a mature form of Adam10 overcame the Sipa1-induced inhibition of T-ALL cell proliferation. T-ALL cell lines expressed Notch ligands in a Notch-signal dependent manner, which contributed to the cell-autonomous Notch activation. Although the initial thymic blast cells barely expressed Notch ligands during the T-ALL development from Rap(high) hematopoietic progenitors in vivo, the ligands were clearly expressed in the T-ALL cells invading extrathymic vital organs. These results reveal a crucial role of the Rap signal in the Notch-dependent T-ALL development and the progression.
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http://dx.doi.org/10.1038/srep07978 | DOI Listing |
Blood Adv
December 2024
University College London, London, United Kingdom.
Chimeric antigen receptor T cell (CAR-T) therapy has proven successful for B cell lymphomas and leukaemias. This success has inspired the development of CAR-T for T cell malignancies. T cell lymphomas and T-ALL are highly heterogenous diseases but are united by poor prognosis in the relapsed/refractory (r/r) setting and the lack of any novel, targeted therapies.
View Article and Find Full Text PDFACS Omega
December 2024
Faculty of Pharmaceutical Sciences, Sojo University, 4-22-1 Ikeda, Nishi-ku, Kumamoto 860-0082, Japan.
Targeting nonapoptotic cell death offers a promising strategy for overcoming apoptosis resistance in cancer. In this study, we developed Tat-Ram13, a 25-mer peptide that fuses the NOTCH1 intracellular domain fragment RAM13 with a cell-penetrating HIV-1 TAT, for the treatment of T-cell acute lymphoblastic leukemia with aberrant NOTCH1 mutation. Tat-Ram13 significantly downregulated NOTCH1-target genes in T-ALL cell lines.
View Article and Find Full Text PDFNat Prod Res
December 2024
State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China.
T-cell acute lymphoblastic leukaemia (T-ALL) is a common childhood malignant tumour, which has poor prognosis and high recurrence rate. Ginsenoside Rh2 (GRh2), a bioactive ingredient of has significant anti-tumour effect. In this study, we found that gene expressions of Jurkat cells were significantly changed in the mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT) signalling pathways after 35 µm GRh2 treatment, involving in JUN, PIEN, AKT3 and MAPK8IP2.
View Article and Find Full Text PDFLeuk Lymphoma
December 2024
Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.
Despite increasing utilization of CAR T-cell therapy, data are lacking regarding long term follow up and risk of infectious complications after the early period following CAR T-cell infusion. In this study, we sought to compare epidemiology and risk factors for early (≤ 3 months) and late (3 months to 1 year) infections. Data were retrospectively collected at six time points: pre-CAR T, day of infusion, and at 3, 6, 9, and 12 months post CAR-T infusion for all consecutive adult patients treated at our institution.
View Article and Find Full Text PDFYale J Biol Med
December 2024
Spencer Center for Vision Research, Byers Eye Institute, Stanford University, Palo Alto, CA, USA.
: To report a case of cystoid macular edema (CME) secondary to immune recovery uveitis (IRU) in a patient with previous history of cytomegalovirus (CMV) retinitis and leukemia, which was successfully treated with tocilizumab (TCZ), an interleukin-6 (IL-6) receptor antagonist. : The clinical records of the case were reviewed, focusing on demographics, image findings, and clinical course. : A 17-year-old female with a past medical history of T-cell acute lymphoblastic leukemia (T-ALL) undergoing chemotherapy for two years presented with active CMV retinitis.
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