المؤلفون: Rafael Fonseca, Sinto Sebastian, Luke Mountjoy, Greg J. Ahmann, Miguel Gonzalez-Velez, Tania Jain, Jeremy T. Larsen, Leif Bergsagel, Marlene Girardo, Talal Hilal

المصدر: Leukemia. 34(11)

مصطلحات موضوعية: Adult, Male, Cancer Research, Antineoplastic Agents, Bone Marrow Cells, Pharmacology, Antioxidants, Immunophenotyping, Text mining, Antineoplastic Combined Chemotherapy Protocols, Medicine, Humans, Immunologic Factors, Sensitivity (control systems), Baseline (configuration management), Aged, business.industry, Hematology, Middle Aged, Prognosis, Oxidative Stress, Treatment Outcome, Oncology, Drug Resistance, Neoplasm, Female, Anti oxidative, business, Multiple Myeloma, Oxidation-Reduction

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3d52dcf6de8aa5453d813404ecc6b7d6Test
https://pubmed.ncbi.nlm.nih.gov/32503975Test

المؤلفون: A. Keith Stewart, Scott Van Wier, Chang Xin Shi, P. Leif Bergsagel, Sonali Panchabhai, Yuan X. Zhu, Marta Chesi, Sinto Sebastian, Rafael Fonseca, Esteban Braggio, Greg J. Ahmann

المصدر: Blood. 129:991-1007

مصطلحات موضوعية: 0301 basic medicine, Thioredoxin reductase, Endoplasmic reticulum, Cereblon, Immunology, Cell Biology, Hematology, Biology, medicine.disease, Biochemistry, 03 medical and health sciences, 030104 developmental biology, 0302 clinical medicine, 030220 oncology & carcinogenesis, medicine, Cancer research, Thioredoxin, Cytotoxicity, Multiple myeloma, Intracellular, Lenalidomide, medicine.drug

الوصف: Lenalidomide is an immunomodulatory drug (IMiDs) with clinical efficacy in multiple myeloma (MM) and other late B-cell neoplasms. Although cereblon (CRBN) is an essential requirement for IMiD action, the complete molecular and biochemical mechanisms responsible for lenalidomide-mediated sensitivity or resistance remain unknown. Here, we report that IMiDs work primarily via inhibition of peroxidase-mediated intracellular H2O2 decomposition in MM cells. MM cells with lower H2O2-decomposition capacity were more vulnerable to lenalidomide-induced H2O2 accumulation and associated cytotoxicity. CRBN-dependent degradation of IKZF1 and IKZF3 was a consequence of H2O2-mediated oxidative stress. Lenalidomide increased intracellular H2O2 levels by inhibiting thioredoxin reductase (TrxR) in cells expressing CRBN, causing accumulation of immunoglobulin light-chain dimers, significantly increasing endoplasmic reticulum stress and inducing cytotoxicity by activation of BH3-only protein Bim in MM. Other direct inhibitors of TrxR and thioredoxin (Trx) caused similar cytotoxicity, but in a CRBN-independent fashion. Our findings could help identify patients most likely to benefit from IMiDs and suggest direct TrxR or Trx inhibitors for MM therapy.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::2184b4da0431c9de7cb7a6733696ffd2Test
https://doi.org/10.1182/blood-2016-09-738872Test

المؤلفون: Ilana Schlam, R Fonseca, Sinto Sebastian, Sonali Panchabhai

المصدر: Leukemia. 31:991-994

مصطلحات موضوعية: musculoskeletal diseases, 0301 basic medicine, Thyroid Hormones, Cancer Research, medicine.medical_specialty, Plasma Cells, Gene Expression, Biology, PKM2, Fusion gene, 03 medical and health sciences, 0302 clinical medicine, hemic and lymphatic diseases, Internal medicine, mental disorders, Gene expression, Biomarkers, Tumor, medicine, Humans, Glycolysis, Multiple myeloma, Hematology, Macrophages, Cell Membrane, Membrane Proteins, Prognosis, medicine.disease, Warburg effect, 030104 developmental biology, Oncology, 030220 oncology & carcinogenesis, Basigin, Cancer research, Carrier Proteins, Multiple Myeloma

الوصف: PKM2 and other key regulators of Warburg effect positively correlate with CD147 (EMMPRIN) gene expression and predict survival in multiple myeloma

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::cb9302da0acbc85f58d09b0fc7a0ebc2Test
https://doi.org/10.1038/leu.2016.389Test

المؤلفون: Rahman Atiqur, Marta Chesi, P. Leif Bergsagel, Yuan Xiao Zhu, Rafael Fonseca, Esteban Braggio, A. Keith Stewart, Sinto Sebastian Chirackal, Gregory J. Ahmann

المصدر: Blood. 134:4410-4410

مصطلحات موضوعية: Chemistry, Cell growth, Immunology, Cell Biology, Hematology, medicine.disease, Biochemistry, Molecular biology, Protein ubiquitination, Glutamine, Cell culture, medicine, Viability assay, Protein demethylation, Multiple myeloma, Lenalidomide, medicine.drug

الوصف: Introduction We have shown that in myeloma (MM) the immunomodulatory drugs (IMiDs) lenalidomide and pomalidomide, in a CRBN dependent fashion, inhibit thioredoxin reductase and thus increase intracellular oxidative stress as a consequence of peroxide accumulation (Sebastian et al. 2017). Accordingly, we have also shown that CRBN expression alone does not fully correlate with lenalidomide sensitivity, as the cells ability to decompose H2O2 is important - MM cells with lower H2O2 decomposition capacity are more sensitive to IMiDs. We hypothezised that the specific metabolic pathways used by cells for biomass production would influence IMiD sensitivity since they also influence this cellular oxidative capacity. Cellular proteins are key elements of this biomass, and required for the proliferation of MM cells and production of immunoglobulin proteins. Methods We cultured MM cells under various nutrients conditions to understand its effect on cell proliferation and drug responses. Cell viability was assessed by MTT assay, the Luminescent Assay, and direct cell counting. MM cells glycolytic rate was measured using the Seahorse XF analyzer. Western blots were performed to quantify various protein expression levels in MM cells cultured under different nutrients conditions. CRBN CRISPR/Cas9 KO plasmid was used to generate CRBN knockout cells and a lentivirus system was used to over-express CRBN in MM cells. Results MM cells resistant to lenalidomide, but still expressing functional CRBN, show a higher glycolytic pathway use than sensitive cells. We found that the lenalidomide sensitive cell line MM1.S is highly dependent on extracellular glutamine for cell proliferation. In contrast, JJN3, a lenalidomide resistant cells line with wild type CRBN, preferentially consumes glucose. We found that glutamine depletion from culture media completely abolished lenalidomide sensitivity in MM1.S cell line. Western blot analysis revealed that antibody production by MM1.S was primarily dependent on glutamine availability, and that JJN3 antibody production was dependent upon glucose availability. While glutamine depletion from culture medium completely abolished lenalidomide sensitivity in MM1.S cell line, IKZF1, and IKZF3 degradation was unchanged. We further studied the role of CRBN in glutamine dependent cellular biomass protein production using isogenic cell lines (+/- wtCRBN). We found that wtCRBN expressing cells proliferate more and show higher antibody production in the presence of glutamine, over CRBN negative isogenic cell lines. Lenalidomide treatment further increased glutamine dependent antibody production in wtCRBN expressing cells. One possibile explanation is that activation of glutamine catabolism can facilitate protein demethylation via the supplementation α-ketoglutarate (α-KG). Therefore, we tested whether lenalidomide treatment could induce protein demethylation in sensitive cell lines. Western blot probed with mono-methyl lysine antibody showed lenalidomide induced protein demethylation. We further confirmed that protein demethylation, and lenalidomide sensitivity is a consequence of elevated α-KG by treating cells with cell-permeable 5-octyl- α-ketoglutarate which act as a substrate of the lysine demethylases. 5-Octyl-α-ketoglutarate treatment inhibited cell proliferation preferentially in wtCRBN expressing cells, and also enhanced lenalidomide induced sensitivity. Protein demethylation is associated with protein ubiquitination and proteasomal degradation. We thus hypothesize that lenalidomide induced protein demethylation also likely increases proteasome inhibitors sensitivity in MM. Conclusion MM cells with preferential glutamine consumption are likely to be more sensitive to lenalidomide, and extracellular glutamine depletion can induce lenalidomide resistance. MM cells expressing CRBN, but not dependent on glutamine for protein biomass production are more likely to be resistant to lenalidomide. Our study postulates that CRBN protein requirement in lenalidomide sensitivity cells is restricted to high glutamine dependency, and that it is quite likely CRBN has a role in glutamine metabolism. Moreover, MM cells that consume more glutamine are under higher oxidative stress and exhibit less H2O2 decomposition capacity and therefore increasing sensitivity to IMiDs. References Sebastian , S., et al., Blood 2017 129:991-1007 Disclosures Stewart: Ono: Consultancy; Roche: Consultancy; Seattle Genetics: Consultancy; Takeda: Consultancy; Amgen: Consultancy, Research Funding; Bristol Myers-Squibb: Consultancy; Celgene: Consultancy, Research Funding; Ionis: Consultancy; Janssen: Consultancy, Research Funding; Oncopeptides: Consultancy. Bergsagel:Janssen Pharmaceuticals: Consultancy; Ionis Pharmaceuticals: Consultancy; Celgene: Consultancy. Fonseca:AbbVie, Amgen, Bayer, Celgene, Kite, Janssen, Juno, Merck, Pharmacylics, Sanofi, Takeda: Other: Consultant/Advisor; Prognosticatin of MM based on Genetic Categorization by FISH: Patents & Royalties; Adaptive Biotechnologies: Other: Scientific Advisory Board.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::7b9d0a6e0c20245b7f66656eb4fcfe8aTest
https://doi.org/10.1182/blood-2019-124967Test

المؤلفون: Sinto Sebastian

المصدر: The Lancet. Haematology. 4(9)

مصطلحات موضوعية: 0301 basic medicine, business.industry, Gene Expression Profiling, Hematology, Computational biology, medicine.disease, Prognosis, Thalidomide, Gene expression profiling, 03 medical and health sciences, 030104 developmental biology, Text mining, medicine, Humans, business, Multiple Myeloma, Multiple myeloma

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3bb2ebd4f8c0cc8a7602f6bae9dfb469Test
https://pubmed.ncbi.nlm.nih.gov/28863804Test

المؤلفون: Sinto Sebastian, R Fonseca, J Yan, S-N Choo, Wee Joo Chng, Siok Bian Ng, Phaik Ju Teoh, Tae-Hoon Chung

المصدر: Leukemia. 28:2066-2074

مصطلحات موضوعية: Cancer Research, Cell Survival, Apoptosis, Haploinsufficiency, Biology, Basal (phylogenetics), Cell Line, Tumor, medicine, Humans, Gene silencing, Gene Silencing, Allele, Promoter Regions, Genetic, Gene, Alleles, Multiple myeloma, Cell Proliferation, Comparative Genomic Hybridization, Hematology, DNA Methylation, Genes, p53, Prognosis, medicine.disease, Treatment Outcome, Oncology, DNA methylation, Cancer research, Tumor Suppressor Protein p53, Signal transduction, Multiple Myeloma, Gene Deletion, Chromosomes, Human, Pair 17, Signal Transduction

الوصف: Hemizygous deletion of 17p13, which harbors the TP53 gene, has been identified in >10% of newly diagnosed multiple myeloma (MM) patients and is associated with poor prognosis. To date, there is no conclusive evidence that TP53 is the critical gene. Furthermore, the functional effect of TP53 haploinsufficiency is not well characterized. By utilizing human myeloma cell lines, we showed that TP53 hemizygous loss was associated with decreased basal expression level with a partially or severely inactivated p53 response upon genotoxic and non-genotoxic stress. The pathway deficiency was manifested as defective p53 transcriptional activities, together with significant resistance to apoptosis. In some cases with p53 WT/- and no p53 protein expression, the remaining allele was silenced by promoter hypermethylation. We also developed a p53 target gene signature to summarize the complexity of the p53 pathway abnormalities in MM and showed that it is strongly associated with genomic complexity and patient survival. In conclusion, this study identified TP53 as the critical gene located in 17p13, and revealed its haploinsufficiency properties in MM. Furthermore, we have elucidated that multiple mechanisms can deregulate the p53 functions and that this has important prognostic impact in MM.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a4bc9f034a8116be2e920b085a48378aTest
https://doi.org/10.1038/leu.2014.102Test

المؤلفون: Sinto, Sebastian, Yuan X, Zhu, Esteban, Braggio, Chang-Xin, Shi, Sonali C, Panchabhai, Scott A, Van Wier, Greg J, Ahmann, Marta, Chesi, P Leif, Bergsagel, A Keith, Stewart, Rafael, Fonseca

المصدر: Blood. 129(8)

مصطلحات موضوعية: Cell Survival, Ubiquitin-Protein Ligases, Hydrogen Peroxide, Endoplasmic Reticulum Stress, Thalidomide, Ikaros Transcription Factor, Oxidative Stress, Cell Line, Tumor, Proteolysis, Humans, Immunologic Factors, Multiple Myeloma, Lenalidomide, Adaptor Proteins, Signal Transducing, Peptide Hydrolases, Peroxidase

الوصف: Lenalidomide is an immunomodulatory drug (IMiDs) with clinical efficacy in multiple myeloma (MM) and other late B-cell neoplasms. Although cereblon (

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=pmid________::a78527794d1f3bf0f2036a2b84ed07f4Test
https://pubmed.ncbi.nlm.nih.gov/28232622Test

المؤلفون: Tania Jain, Luke Mountjoy, Jeremy T. Larsen, Marlene Girardo, Sinto Sebastian Chirackal, Rafael Fonseca

المصدر: Blood. 132:4443-4443

مصطلحات موضوعية: Oncology, medicine.medical_specialty, Combination therapy, medicine.diagnostic_test, medicine.drug_class, business.industry, Immunology, Cell Biology, Hematology, Monoclonal antibody, medicine.disease, Biochemistry, Flow cytometry, Transplantation, Internal medicine, medicine, Proteasome inhibitor, Prospective cohort study, business, Cytometry, Multiple myeloma, medicine.drug

الوصف: Introduction - IMIDs are critical in the treatment of multiple myeloma (MM). Unfortunately, many patients become resistant and this is a major challenge in MM therapy. IMID resistance can be caused by CRBN mutations (rarely) and by upregulation of specific antioxidative mechanisms. We hypothesized that measuring baseline antioxidative capacity might be a useful predictor of IMID sensitivity in the clinic. Methods - To develop a quantitative assay for determining cellular antioxidative capacity of MM cells we measured total cellular oxidized flavin adenine dinucleotide (FAD) after treatment with H2O2. FAD has auto-fluorescent properties that can be measured via flow cytometry. Cells with high antioxidative capacity generate more FAD, and cells with low anti-oxidative capacity generate less FAD. MM cells with an increase in FAD after H2O2 were considered IMID resistant and those with no change in FAD were considered IMID sensitive (Figure 1). Clinical IMID resistance/sensitivity was defined clinically during blinded retrospective review, with disease progression based on the IMWG criteria. After blinded review of clinical outcomes, the patient flow cytometry results were disclosed to evaluate the predictive value of the flow cytometry assay for detection of IMID resistance. Results - Of 40 patients who underwent testing, 26 were IMID resistant via flow and were considered as being clinical resistant 17 (65%). Conversely, 14 patients were IMID sensitive via flow and 12 (86%) were considered to be clinical sensitive. There was a significant correlation between clinical assessment and flow cytometry in determination of IMID resistance patterns (Table 1). The sensitivity and specificity of our assay was 89% and 57% with a positive and negative predictive value of 65% and 86% respectively. A limitation of our clinical assessment was that 16 patients (38%) were treated with combination therapy; IMIDs plus a proteasome inhibitor or a monoclonal antibody. Of the 11 patients with discordant results by flow and clinical outcome, 7 (64%) were not on therapy at the time of testing and 6 (55%) had flow testing on the bone marrow sample performed on day 100 following an autologous transplant. Two (7%) of the 29 patients with correlative results were off all therapy at the time of testing, 1 with testing on the day 100 marrow sample after transplant. Conclusions - This early testing of our assay shows promising results predicting clinical sensitivity via our flow based assay. The testing demonstrates a high sensitivity and negative predictive value, with less ability to assess for resistance. However, there were limitations to this study. The majority of patients with discordant results were off IMID therapy at the time of flow cytometry and many of these were assessed on transplant day 100 marrow samples. Depth of measureable residual disease was not readily available on all marrow samples tested. It is probable that flow testing for IMID resistance is inaccurate in patients with deeper responses to therapy, especially those who are minimum residual disease (MRD) negative. Additionally, several patients were on combination IMID, proteasome inhibitor, and monoclonal antibody. It is possible that clinical IMID resistance was not detected due to the anti-MM activity of the additional therapies. Additional larger scale prospective studies are needed to validate these findings as this method of testing could potentially provide providers with powerful information allowing them to personalize therapy for their patients. Disclosures Fonseca: Mayo Clinic: Employment; Amgen: Consultancy.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::943015edb3ba80a1c6ae17b7e6c1ab83Test
https://doi.org/10.1182/blood-2018-99-113710Test

المؤلفون: Chirackal, Sinto Sebastian, Hitosugi, Taro, Ahmann, Gregory, Braggio, Esteban, Chesi, Marta, Bergsagel, P. Leif, Fonseca, Rafael

المصدر: Blood; November 2023, Vol. 142 Issue: 1, Number 1 Supplement 1 p3291-3291, 1p

مستخلص: Introduction

المؤلفون: Sinto Sebastian, Guangzhi Dong, Hwan Ki Park, Fred Duafalia Dudimah, Peiwen Fei, Jayabal Panneerselvam, Jun Zhang

المصدر: Cell Cycle. 10:2574-2582

مصطلحات موضوعية: Mitosis, Biology, Cell Line, Mice, Cell Cycle News & Views, chemistry.chemical_compound, Radiation, Ionizing, CDC2 Protein Kinase, Phosphoprotein Phosphatases, Animals, Humans, CHEK1, Phosphorylation, Molecular Biology, Mitotic catastrophe, Tissue homeostasis, Cyclin-dependent kinase 1, Wild type, Tyrosine phosphorylation, Cell Biology, G2-M DNA damage checkpoint, Cell biology, G2 Phase Cell Cycle Checkpoints, Protein Phosphatase 2C, chemistry, M Phase Cell Cycle Checkpoints, Tumor Suppressor Protein p53, Developmental Biology

الوصف: Wip1, a human protein Ser/Thr phosphatase also called PPM1D, stands for wild type p53 induced phosphatase 1. Emerging evidences indicate that Wip1 can act as an oncogene largely by turning off DNA damage checkpoint responses. Here we report an unrecognized role of Wipl in normally growing cells. Wip1 can be induced by wild type p53 under not only stressed but also non-stressed conditions. It can trigger G 2/M arrest in wild type p53 containing cells, which was attributed to the decreased Cdc2 kinase activity resulting at least partly from a high level of inhibitory tyrosine phosphorylation on Cdc2 protein at Tyr-15. Furthermore, we also found that Wip1 not only causes G 2/M arrest but also decreases cell death triggered by microtubule assembly inhibitor in mouse fibroblasts when wild type p53 function was restored. These results indicate that Wip1 can provide ample time for wild type p53-containing cells to prepare entry into mitosis and avoid encountering mitotic catastrophe. Therefore, Wipl may play important roles in cell/tissue homeostasis maintained by wild type p53 under normal conditions, enhancing our understanding of how p53 makes cell-fate decisions.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::62dca963821410eacbe28fb34e1c0da7Test
https://doi.org/10.4161/cc.10.15.15923Test