Subject(s)
B-Lymphocytes/immunology , Palatine Tonsil/immunology , Palatine Tonsil/microbiology , Tonsillitis/immunology , Tonsillitis/microbiology , Adenoidectomy , Adolescent , Child , Child, Preschool , Female , Flow Cytometry , Humans , Immunity, Mucosal , Immunophenotyping , Male , Palatine Tonsil/surgery , Principal Component Analysis , Tonsillectomy , Tonsillitis/surgery , Young AdultABSTRACT
Histone deacetylases (HDACs) have been identified as therapeutic targets due to their regulatory function in chromatin structure and organization. Here, we analyzed the therapeutic effect of LBH589, a class I-II HDAC inhibitor, in acute lymphoblastic leukemia (ALL). In vitro, LBH589 induced dose-dependent antiproliferative and apoptotic effects, which were associated with increased H3 and H4 histone acetylation. Intravenous administration of LBH589 in immunodeficient BALB/c-RAG2(-/-)γc(-/-) mice in which human-derived T and B-ALL cell lines were injected induced a significant reduction in tumor growth. Using primary ALL cells, a xenograft model of human leukemia in BALB/c-RAG2(-/-)γc(-/-) mice was established, allowing continuous passages of transplanted cells to several mouse generations. Treatment of mice engrafted with T or B-ALL cells with LBH589 induced an in vivo increase in the acetylation of H3 and H4, which was accompanied with prolonged survival of LBH589-treated mice in comparison with those receiving vincristine and dexamethasone. Notably, the therapeutic efficacy of LBH589 was significantly enhanced in combination with vincristine and dexamethasone. Our results show the therapeutic activity of LBH589 in combination with standard chemotherapy in pre-clinical models of ALL and suggest that this combination may be of clinical value in the treatment of patients with ALL.
Subject(s)
Apoptosis/drug effects , Dexamethasone/pharmacology , Histone Deacetylase Inhibitors/pharmacology , Hydroxamic Acids/pharmacology , Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , Vincristine/pharmacology , Animals , Antineoplastic Agents, Hormonal/pharmacology , Antineoplastic Agents, Phytogenic/pharmacology , Antineoplastic Combined Chemotherapy Protocols , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Cell Proliferation/drug effects , DNA Methylation , DNA-Binding Proteins/physiology , Drug Synergism , Female , Gene Expression Profiling , Histones/metabolism , Humans , Immunoenzyme Techniques , Indoles , Mice , Mice, Inbred BALB C , Oligonucleotide Array Sequence Analysis , Panobinostat , Polymorphism, Single Nucleotide/genetics , Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics , Precursor Cell Lymphoblastic Leukemia-Lymphoma/metabolism , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Tumor Cells, Cultured , Xenograft Model Antitumor AssaysABSTRACT
An ultra high performance liquid chromatography tandem mass spectrometry method (UHPLC-MS/MS) was developed and validated for the quantitation of LBH589, a novel histone deacetylase inhibitor (HDACi), in mouse plasma and tissues (liver, spleen, kidney and lung). Tobramycin was employed as the internal standard. Separation was performed on an Acquity UPLC™ BEH column, with a mobile phase consisting of 10% water (with 0.1% of trifluoroacetic acid) and 90% methanol (with 0.1% trifluoroacetic acid). LBH589 and tobramycin were determined using an electrospray ionization (ESI) interface. Detection was performed on electrospray positive ionization mass spectrometry by multiple reaction monitoring of the transitions of LBH589 at m/z 349.42â157.95 and of tobramycin at 468.2â163. Calibration curves for the UHPLC method (0.0025-1 µg/mL for plasma and tissue homogenates, equivalent to 0.0357-14.2857 µg/g for tissue samples) showed a linear range of detector responses (r>0.998). Intra-batch and inter-batch precision expressed as coefficient of variation (CV) ranged from 0.92 to 8.40%. Accuracy expressed as bias, ranged from -2.41 to 2.62%. The lower limit of quantitation (LLOQ) was 0.0025 µg/mL for both plasma and tissue homogenate samples, equivalent to 0.0357 µg/g tissue. This method was successfully applied to quantify LBH589 in plasma and tissue samples obtained after the intraperitoneal administration of a single dose of 20 mg/kg of LBH589 in BALB/c mice.
