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1.
Med Teach ; : 1-6, 2023 Dec 26.
Article in English | MEDLINE | ID: mdl-38146711

ABSTRACT

BACKGROUND: Crafting quality assessment questions in medical education is a crucial yet time-consuming, expertise-driven undertaking that calls for innovative solutions. Large language models (LLMs), such as ChatGPT (Chat Generative Pre-Trained Transformer), present a promising yet underexplored avenue for such innovations. AIMS: This study explores the utility of ChatGPT to generate diverse, high-quality medical questions, focusing on multiple-choice questions (MCQs) as an illustrative example, to increase educator's productivity and enable self-directed learning for students. DESCRIPTION: Leveraging 12 strategies, we demonstrate how ChatGPT can be effectively used to generate assessment questions aligned with Bloom's taxonomy and core knowledge domains while promoting best practices in assessment design. CONCLUSION: Integrating LLM tools like ChatGPT into generating medical assessment questions like MCQs augments but does not replace human expertise. With continual instruction refinement, AI can produce high-standard questions. Yet, the onus of ensuring ultimate quality and accuracy remains with subject matter experts, affirming the irreplaceable value of human involvement in the artificial intelligence-driven education paradigm.

2.
Blood ; 134(23): 2046-2058, 2019 12 05.
Article in English | MEDLINE | ID: mdl-31434700

ABSTRACT

Oncogenic EZH2 is overexpressed and extensively involved in the pathophysiology of different cancers including extranodal natural killer/T-cell lymphoma (NKTL). However, the mechanisms regarding EZH2 upregulation is poorly understood, and it still remains untargetable in NKTL. In this study, we examine EZH2 protein turnover in NKTL and identify MELK kinase as a regulator of EZH2 ubiquitination and turnover. Using quantitative mass spectrometry analysis, we observed a MELK-mediated increase of EZH2 S220 phosphorylation along with a concomitant loss of EZH2 K222 ubiquitination, suggesting a phosphorylation-dependent regulation of EZH2 ubiquitination. MELK inhibition through both chemical and genetic means led to ubiquitination and destabilization of EZH2 protein. Importantly, we determine that MELK is upregulated in NKTL, and its expression correlates with EZH2 protein expression as determined by tissue microarray derived from NKTL patients. FOXM1, which connected MELK to EZH2 signaling in glioma, was not involved in mediating EZH2 ubiquitination. Furthermore, we identify USP36 as the deubiquitinating enzyme that deubiquitinates EZH2 at K222. These findings uncover an important role of MELK and USP36 in mediating EZH2 stability in NKTL. Moreover, MELK overexpression led to decreased sensitivity to bortezomib treatment in NKTL based on deprivation of EZH2 ubiquitination. Therefore, modulation of EZH2 ubiquitination status by targeting MELK may be a new therapeutic strategy for NKTL patients with poor bortezomib response.


Subject(s)
Enhancer of Zeste Homolog 2 Protein/metabolism , Gene Expression Regulation, Neoplastic , Lymphoma, Extranodal NK-T-Cell/metabolism , Neoplasm Proteins/metabolism , Protein Serine-Threonine Kinases/metabolism , Bortezomib/therapeutic use , Cell Line, Tumor , Enhancer of Zeste Homolog 2 Protein/genetics , Forkhead Box Protein M1/genetics , Forkhead Box Protein M1/metabolism , Humans , Lymphoma, Extranodal NK-T-Cell/drug therapy , Lymphoma, Extranodal NK-T-Cell/genetics , Lymphoma, Extranodal NK-T-Cell/pathology , Neoplasm Proteins/genetics , Phosphorylation/genetics , Protein Serine-Threonine Kinases/genetics , Protein Stability , Ubiquitin Thiolesterase/genetics , Ubiquitin Thiolesterase/metabolism , Ubiquitination/genetics
3.
Biomolecules ; 12(8)2022 08 08.
Article in English | MEDLINE | ID: mdl-36008987

ABSTRACT

Piperidine pharmacophore-containing compounds have demonstrated therapeutic efficacy against a range of diseases and are now being investigated in cancer. A series of 3-chloro-3-methyl-2,6-diarylpiperidin-4-ones, compounds (I-V) were designed and synthesized for their evaluation as a potential anti-cancer agent. Compounds II and IV reduced the growth of numerous hematological cancer cell lines while simultaneously increasing the mRNA expression of apoptosis-promoting genes, p53 and Bax. Molecular docking analyses confirmed that compounds can bind to 6FS1, 6FSO (myeloma), 6TJU (leukemia), 5N21, and 1OLL (NKTL). Computational ADMET research confirmed the essential physicochemical, pharmacokinetic, and drug-like characteristics of compounds (I-V). The results revealed that these compounds interact efficiently with active site residues and that compounds (II) and (V) can be further evaluated as potential therapeutic candidates.


Subject(s)
Antineoplastic Agents , Antineoplastic Agents/chemistry , Molecular Docking Simulation , Molecular Structure , Structure-Activity Relationship
4.
Biomolecules ; 12(9)2022 09 08.
Article in English | MEDLINE | ID: mdl-36139103

ABSTRACT

CD38 was first discovered as a T-cell antigen and has since been found ubiquitously expressed in various hematopoietic cells, including plasma cells, NK cells, B cells, and granulocytes. More importantly, CD38 expression levels on malignant hematopoietic cells are significantly higher than counterpart healthy cells, thus presenting itself as a promising therapeutic target. In fact, for many aggressive hematological cancers, including CLL, DLBCL, T-ALL, and NKTL, CD38 expression is significantly associated with poorer prognosis and a hyperproliferative or metastatic phenotype. Studies have shown that, beyond being a biomarker, CD38 functionally mediates dysregulated survival, adhesion, and migration signaling pathways, as well as promotes an immunosuppressive microenvironment conducive for tumors to thrive. Thus, targeting CD38 is a rational approach to overcoming these malignancies. However, clinical trials have surprisingly shown that daratumumab monotherapy has not been very effective in these other blood malignancies. Furthermore, extensive use of daratumumab in MM is giving rise to a subset of patients now refractory to daratumumab treatment. Thus, it is important to consider factors modulating the determinants of response to CD38 targeting across different blood malignancies, encompassing both the transcriptional and post-transcriptional levels so that we can diversify the strategy to enhance daratumumab therapeutic efficacy, which can ultimately improve patient outcomes.


Subject(s)
Antineoplastic Agents, Immunological , Hematologic Neoplasms , Multiple Myeloma , ADP-ribosyl Cyclase 1/genetics , ADP-ribosyl Cyclase 1/metabolism , Antibodies, Monoclonal/pharmacology , Antibodies, Monoclonal/therapeutic use , Antineoplastic Agents, Immunological/therapeutic use , Hematologic Neoplasms/drug therapy , Hematologic Neoplasms/genetics , Humans , Multiple Myeloma/drug therapy , Tumor Microenvironment
5.
PLoS One ; 17(1): e0261469, 2022.
Article in English | MEDLINE | ID: mdl-35077445

ABSTRACT

B-cell receptor (BCR) signalling is critical for the survival of B-cell lymphomas and is a therapeutic target of drugs such as Ibrutinib. However, the role of T-cell receptor (TCR) signalling in the survival of T/Natural Killer (NK) lymphomas is not clear. ZAP-70 (zeta associated protein-70) is a cytoplasmic tyrosine kinase with a critical role in T-cell receptor (TCR) signalling. It has also been shown to play a role in normal NK cell signalling and activation. High ZAP-70 expression has been detected by immunohistochemistry in peripheral T cell lymphoma (PTCL) and NK cell lymphomas (NKTCL). We therefore, studied the role of TCR pathways in mediating the proliferation and survival of these malignancies through ZAP-70 signalling. ZAP-70 protein was highly expressed in T cell lymphoma cell lines (JURKAT and KARPAS-299) and NKTCL cell lines (KHYG-1, HANK-1, NK-YS, SNK-1 and SNK-6), but not in multiple B-cell lymphoma cell lines. siRNA depletion of ZAP-70 suppressed the phosphorylation of ZAP-70 substrates, SLP76, LAT and p38MAPK, but did not affect cell viability or induce apoptosis in these cell lines. Similarly, while stable overexpression of ZAP-70 mediates increased phosphorylation of target substrates in the TCR pathway, it does not promote increased survival or growth of NKTCL cell lines. The epidermal growth factor receptor (EGFR) inhibitor Gefitinib, which has off-target activity against ZAP-70, also did not show any differential cell kill between ZAP-70 overexpressing (OE) or knockdown (KD) cell lines. Whole transcriptome RNA sequencing highlighted that there was very minimal differential gene expression in three different T/NK cell lines induced by ZAP-70 KD. Importantly, ZAP-70 KD did not significantly enrich for any downstream TCR related genes and pathways. Altogether, this suggests that high expression and constitutive signalling of ZAP-70 in T/NK lymphoma is not critical for cell survival or downstream TCR-mediated signalling and gene expression. ZAP-70 therefore may not be a suitable therapeutic target in T/NK cell malignancies.


Subject(s)
Gefitinib/pharmacology , Lymphoma, Extranodal NK-T-Cell/metabolism , Lymphoma, T-Cell, Peripheral/metabolism , Up-Regulation , ZAP-70 Protein-Tyrosine Kinase/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Gene Expression Regulation, Neoplastic , Gene Knockdown Techniques , Humans , Jurkat Cells , Lymphoma, Extranodal NK-T-Cell/genetics , Lymphoma, T-Cell, Peripheral/genetics , Phosphorylation/drug effects , Signal Transduction/drug effects , ZAP-70 Protein-Tyrosine Kinase/genetics
6.
F1000Res ; 10: 1274, 2021.
Article in English | MEDLINE | ID: mdl-35528953

ABSTRACT

Background: Customer churn is a term that refers to the rate at which customers leave the business. Churn could be due to various factors, including switching to a competitor, cancelling their subscription because of poor customer service, or discontinuing all contact with a brand due to insufficient touchpoints. Long-term relationships with customers are more effective than trying to attract new customers. A rise of 5% in customer satisfaction is followed by a 95% increase in sales. By analysing past behaviour, companies can anticipate future revenue. This article will look at which variables in the Net Promoter Score (NPS) dataset influence customer churn in Malaysia's telecommunications industry.  The aim of This study was to identify the factors behind customer churn and propose a churn prediction framework currently lacking in the telecommunications industry.   Methods: This study applied data mining techniques to the NPS dataset from a Malaysian telecommunications company in September 2019 and September 2020, analysing 7776 records with 30 fields to determine which variables were significant for the churn prediction model. We developed a propensity for customer churn using the Logistic Regression, Linear Discriminant Analysis, K-Nearest Neighbours Classifier, Classification and Regression Trees (CART), Gaussian Naïve Bayes, and Support Vector Machine using 33 variables.   Results: Customer churn is elevated for customers with a low NPS. However, an immediate helpdesk can act as a neutral party to ensure that the customer needs are met and to determine an employee's ability to obtain customer satisfaction.   Conclusions: It can be concluded that CART has the most accurate churn prediction (98%). However, the research is prohibited from accessing personal customer information under Malaysia's data protection policy. Results are expected for other businesses to measure potential customer churn using NPS scores to gather customer feedback.


Subject(s)
Commerce , Telecommunications , Bayes Theorem , Consumer Behavior , Forecasting
7.
J Immunother Cancer ; 9(7)2021 07.
Article in English | MEDLINE | ID: mdl-34215687

ABSTRACT

BACKGROUND: The potential therapeutic efficacy of daratumumab in natural killer T-cell lymphoma (NKTL) was highlighted when its off-label usage produced sustained remission in a patient with highly refractory disease. This is corroborated recently by a phase II clinical trial which established that daratumumab monotherapy is well tolerated and displayed encouraging response in relapsed/refractory NKTL patients. However, little is known regarding the molecular factors central to the induction and regulation of the daratumumab-mediated antitumor response in NKTL. METHODS: CD38 expression was studied via immunohistochemistry, multiplex immunofluorescence and correlated with clinical characteristics of the patient. The therapeutic efficacy of daratumumab was studied in vitro via CellTiter-Glo (CTG) assay, complement-dependent cytotoxicity (CDC), antibody-dependent cell cytotoxicity (ADCC), and in vivo, via a patient-derived xenograft mouse model of NKTL, both as a single agent and in combination with L-asparaginase. Signaling mechanisms were characterized via pharmacologic treatment, RNA silencing, flow cytometry and corroborated with public transcriptomic data of NKTL. RESULTS: Epstein-Barr virus-positive NKTL patients significantly express CD38 with half exhibiting high expression. Daratumumab effectively triggers Fc-mediated ADCC and CDC in a CD38-dependent manner. Importantly, daratumumab monotherapy and combination therapy with L-asparaginase significantly suppresses tumor progression in vivo. Ablation of complement inhibitory proteins (CIP) demonstrate that CD55 and CD59, not CD46, are critical for the induction of CDC. Notably, CD55 and CD59 expression were significantly elevated in the late stages of NKTL. Increasing the CD38:CIP ratio through sequential CIP knockdown, followed by CD38 upregulation via All-Trans Retinoic Acid treatment, potently augments complement-mediated lysis in cells previously resistant to daratumumab. The CD38:CIP ratio consistently demonstrates a statistically superior correlation to antitumor efficacy of daratumumab than CD38 or CIP expression alone. CONCLUSION: This study characterizes CD38 as an effective target for a subset of NKTL patients and the utilization of the CD38:CIP ratio as a more robust identifier for patient stratification and personalisation of treatment. Furthermore, elucidation of factors which sensitize the complement-mediated response provides an alternative approach toward optimizing therapeutic efficacy of daratumumab where CDC remains a known limiting factor. Altogether, these results propose a strategic rationale for further evaluation of single or combined daratumumab treatment in the clinic for NKTL.


Subject(s)
Antibodies, Monoclonal/therapeutic use , Epstein-Barr Virus Infections/drug therapy , Killer Cells, Natural/drug effects , Lymphoma, T-Cell/drug therapy , Animals , Antibodies, Monoclonal/pharmacology , Disease Models, Animal , Female , Humans , Male , Mice
8.
Eur J Med Chem ; 184: 111755, 2019 Dec 15.
Article in English | MEDLINE | ID: mdl-31627059

ABSTRACT

Herein, we report the discovery of a dual histone deacetylase inhibitor displaying a unique HDAC3/6 selectivity profile. An initial strategy to merge two epigenetic pharmacophores resulted in the discovery of potent HDAC6 inhibitors with selectivity over HDAC1. Screening in an HDAC panel revealed additional low nanomolar inhibition only against HDAC3. Low micromolar antiproliferative activities against two breast cancer and four hematological cancer cell lines was supported by pharmacodynamic studies on a preferred molecule, 24c, substantiating the HDAC inhibitory profile in cells. Apoptosis was identified as one of the main cell death pathways. Modelling studies of 24c against HDAC1,2,3 and 6 further provided insights on the orientation of specific residues relevant to compound potency, explaining the observed HDAC3/6 selectivity. A subset of the compounds also exhibited good antimalarial activities, particularly against the chloroquine-resistant strain K1 of P.falciparum. In vitro studies revealed a favourable DMPK profile warranting further investigation of the therapeutic potential of these compounds.


Subject(s)
Antimalarials/pharmacology , Drug Discovery , Histone Deacetylase 6/antagonists & inhibitors , Histone Deacetylase Inhibitors/pharmacology , Histone Deacetylases/metabolism , Plasmodium falciparum/drug effects , Animals , Antimalarials/chemical synthesis , Antimalarials/chemistry , Apoptosis/drug effects , Cell Line, Tumor , Cell Survival/drug effects , Dose-Response Relationship, Drug , Histone Deacetylase 6/metabolism , Histone Deacetylase Inhibitors/chemical synthesis , Histone Deacetylase Inhibitors/chemistry , Humans , Mice , Microsomes, Liver/chemistry , Microsomes, Liver/metabolism , Molecular Structure , Parasitic Sensitivity Tests , Rats , Structure-Activity Relationship
9.
Eur J Med Chem ; 158: 593-619, 2018 Oct 05.
Article in English | MEDLINE | ID: mdl-30243158

ABSTRACT

Specifically blocking more than one oncogenic pathway simultaneously in a cancer cell with a combination of different drugs is the mainstay of the majority of cancer treatments. Being able to do this via two targeted pathways without inducing side effects through a general mechanism, such as chemotherapy, could bring benefit to patients. In this work we describe a new dual inhibitor of the JAK-STAT and HDAC pathways through designing and developing two types of molecule based on the JAK2 selective inhibitor XL019 and the pan-HDAC inhibitor, vorinostat. Both series of compounds had examples with low nanomolar JAK2 and HDAC1/6 inhibition. In some cases good HDAC1 selectivity was achieved while retaining HDAC6 activity. The observed potency is explained through molecular docking studies of all three enzymes. One example, 69c had 16-25 fold selectivity against the three other JAK-family proteins JAK1, JAK3 and TYK2. A number of compounds had sub-micromolar potencies against a panel of 4 solid tumor cell lines and 4 hematological cell lines with the most potent compound, 45h, having a cellular IC50 of 70 nM against the multiple myeloma cell line KMS-12-BM. Evidence of both JAK and HDAC pathway inhibition is presented in Hela cells showing that both pathways are modulated. Evidence of apoptosis with two compounds in 4 sold tumor cell lines is also presented.


Subject(s)
Antineoplastic Agents/chemistry , Drug Design , Histone Deacetylase Inhibitors/chemistry , Hydroxamic Acids/chemistry , Janus Kinase 2/antagonists & inhibitors , Proline/analogs & derivatives , Protein Kinase Inhibitors/chemistry , Pyrimidines/chemistry , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , HeLa Cells , Histone Deacetylase Inhibitors/chemical synthesis , Histone Deacetylase Inhibitors/pharmacology , Humans , Hydroxamic Acids/chemical synthesis , Hydroxamic Acids/pharmacology , Janus Kinase 2/metabolism , Molecular Docking Simulation , Neoplasms/drug therapy , Neoplasms/metabolism , Proline/chemical synthesis , Proline/chemistry , Proline/pharmacology , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacology , Pyrimidines/chemical synthesis , Pyrimidines/pharmacology , Structure-Activity Relationship , Vorinostat
10.
Front Pharmacol ; 9: 365, 2018.
Article in English | MEDLINE | ID: mdl-29773987

ABSTRACT

Several lines of evidence have demonstrated that deregulated activation of NF-κB plays a pivotal role in the initiation and progression of a variety of cancers including multiple myeloma (MM). Therefore, novel molecules that can effectively suppress deregulated NF-κB upregulation can potentially reduce MM growth. In this study, the effect of celastrol (CSL) on patient derived CD138+ MM cell proliferation, apoptosis, cell invasion, and migration was investigated. In addition, we studied whether CSL can potentiate the apoptotic effect of bortezomib, a proteasome inhibitor in MM cells and in a xenograft mouse model. We found that CSL significantly reduced cell proliferation and enhanced apoptosis when used in combination with bortezomib and upregulated caspase-3 in these cells. CSL also inhibited invasion and migration of MM cells through the suppression of constitutive NF-κB activation and expression of downstream gene products such as CXCR4 and MMP-9. Moreover, CSL when administered either alone or in combination with bortezomib inhibited MM tumor growth and decreased serum IL-6 and TNF-α levels. Overall, our results suggest that CSL can abrogate MM growth both in vitro and in vivo and may serve as a useful pharmacological agent for the treatment of myeloma and other hematological malignancies.

11.
Oncotarget ; 8(60): 101847-101864, 2017 Nov 24.
Article in English | MEDLINE | ID: mdl-29254208

ABSTRACT

The PI3K/mTOR/AKT pathway is an integral regulator of survival and drug resistance in multiple myeloma (MM). VS-5584 was synthesized with dual-specific and equipotent activity against mTORC1/2 and all four Class I PI3K isoforms so as to durably inhibit this pathway. We show that VS-5584 is highly efficacious against MM cell lines even in the presence of IL-6 and IGF-1 and that this growth inhibition is partially dependent on Bim. Importantly, VS-5584 triggers apoptosis in patient cells with a favorable therapeutic index. Gene expression profiling revealed a VS-5584-induced upregulation of RARRES3, a class II tumor suppressor gene. MM patient databases, UAMS and APEX, show that RARRES3 is under-expressed in 11q13 subsets which correlates with the reduced effectiveness of VS-5584 in 11q13 cell lines. Silencing RARRES3 expression significantly rescues VS-5584-induced cell death and increases cyclin D2 expression but not cyclin D1 or other cyclins implying a role for RARRES3 in cell cycle arrest. In vivo, VS-5584 significantly reduces the tumor burden of MM mouse xenografts. We further identified that VS-5584 synergised with Dexamethasone, Velcade, and exceptionally so with HDAC inhibitor, Panobinostat. Interestingly, this was consistently observed in several patient samples, proposing a promising novel clinical strategy for combination treatment especially in relapsed/refractory patients.

12.
J Med Chem ; 60(20): 8336-8357, 2017 10 26.
Article in English | MEDLINE | ID: mdl-28953386

ABSTRACT

Concomitant inhibition of multiple oncogenic pathways is a desirable goal in cancer therapy. To achieve such an outcome with a single molecule would simplify treatment regimes. Herein the core features of ruxolitinib (1), a marketed JAK1/2 inhibitor, have been merged with the HDAC inhibitor vorinostat (2), leading to new molecules that are bispecific targeted JAK/HDAC inhibitors. A preferred pyrazole substituted pyrrolopyrimidine, 24, inhibits JAK1 and HDACs 1, 2, 3, 6, and 10 with IC50 values of less than 20 nM, is <100 nM potent against JAK2 and HDAC11, and is selective for the JAK family against a panel of 97 kinases. Broad cellular antiproliferative potency of 24 is supported by demonstration of JAK-STAT and HDAC pathway blockade in hematological cell lines. Methyl analogue 45 has an even more selective profile. This study provides new leads for assessment of JAK and HDAC pathway dual inhibiton achieved with a single molecule.


Subject(s)
Histone Deacetylase Inhibitors/pharmacology , Hydroxamic Acids/pharmacology , Janus Kinase 1/antagonists & inhibitors , Janus Kinase 2/antagonists & inhibitors , Protein Kinase Inhibitors/pharmacology , Pyrazoles/pharmacology , Animals , Cell Line, Tumor , Chromatography, Liquid , Histone Deacetylase Inhibitors/pharmacokinetics , Humans , Hydroxamic Acids/chemistry , Janus Kinase 1/chemistry , Janus Kinase 2/chemistry , Mice , Mice, Inbred BALB C , Models, Molecular , Nitriles , Protein Kinase Inhibitors/pharmacokinetics , Pyrazoles/chemistry , Pyrimidines , Spectrum Analysis , Vorinostat
13.
J Med Chem ; 59(18): 8233-62, 2016 Sep 22.
Article in English | MEDLINE | ID: mdl-27541357

ABSTRACT

Blockage of more than one oncoprotein or pathway is now a standard approach in modern cancer therapy. Multiple inhibition is typically achieved with two or more drugs. Herein, we describe a pharmacophore merging strategy combining the JAK2/FLT3 inhibitor pacritnib with the pan-HDAC inhibitor, vorinostat, to create bispecific single molecules with both JAK and HDAC targeted inhibition. A preferred ether hydroxamate, 51, inhibits JAK2 and HDAC6 with low nanomolar potency, is <100 nM potent against HDACs 2 and 10, submicromolar potent against HDACs 1, 8, and 11, and >50-fold selective for JAK2 in a panel of 97 kinases. Broad cellular antiproliferative potency is supported by demonstration of JAK-STAT and HDAC pathway blockade in several hematological cell lines, inhibition of colony formation in HEL cells, and analysis of apoptosis. This study provides new tool compounds for further exploration of dual JAK-HDAC pathway inhibiton achieved with a single molecule.


Subject(s)
Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Bridged-Ring Compounds/chemistry , Bridged-Ring Compounds/pharmacology , Histone Deacetylase Inhibitors/chemistry , Histone Deacetylase Inhibitors/pharmacology , Janus Kinase 2/antagonists & inhibitors , Pyrimidines/chemistry , Pyrimidines/pharmacology , Apoptosis/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Hematologic Neoplasms/drug therapy , Hematologic Neoplasms/metabolism , Humans , Models, Molecular , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Signal Transduction/drug effects
14.
Oncotarget ; 5(3): 634-48, 2014 Feb 15.
Article in English | MEDLINE | ID: mdl-24504138

ABSTRACT

Multiple myeloma (MM) is a B cell malignancy characterized by clonal proliferation of plasma cells in the bone marrow. With the advent of novel targeted agents, the median survival rate has increased to 5 -7 years. However, majority of patients with myeloma suffer relapse or develop chemoresistance to existing therapeutic agents. Thus, there is a need to develop novel alternative therapies for the treatment of MM. Thus in the present study, we investigated whether thymoquinone (TQ), a bioactive constituent of black seed oil, could suppress the proliferation and induce chemosensitization in human myeloma cells and xenograft mouse model. Our results show that TQ inhibited the proliferation of MM cells irrespective of their sensitivity to doxorubicin, melphalan or bortezomib. Interestingly, TQ treatment also resulted in a significant inhibition in the proliferation of CD138+ cells isolated from MM patient samples in a concentration dependent manner. TQ also potentiated the apoptotic effects of bortezomib in various MM cell lines through the activation of caspase-3, resulting in the cleavage of PARP. TQ treatment also inhibited chemotaxis and invasion induced by CXCL12 in MM cells. Furthermore, in a xenograft mouse model, TQ potentiated the antitumor effects of bortezomib (p<0.05, vehicle versus bortezomib + TQ; p<0.05, bortezomib versus bortezomib + TQ), and this correlated with modulation of various markers for survival and angiogenesis, such as Ki-67, vascular endothelial growth factor (VEGF), Bcl-2 and p65 expression. Overall, our results demonstrate that TQ can enhance the anticancer activity of bortezomib in vitro and in vivo and may have a substantial potential in the treatment of MM.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Benzoquinones/pharmacology , Boronic Acids/pharmacology , Multiple Myeloma/drug therapy , NF-kappa B/genetics , Pyrazines/pharmacology , Animals , Apoptosis/drug effects , Benzoquinones/administration & dosage , Boronic Acids/administration & dosage , Bortezomib , Cell Line, Tumor , Cell Proliferation/drug effects , Disease Models, Animal , Drug Synergism , Humans , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Multiple Myeloma/genetics , Multiple Myeloma/metabolism , Multiple Myeloma/pathology , NF-kappa B/metabolism , Pyrazines/administration & dosage , Random Allocation , Signal Transduction , Xenograft Model Antitumor Assays
15.
Mol Cancer Ther ; 12(2): 151-61, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23270925

ABSTRACT

Dysregulation of the PI3K/mTOR pathway, either through amplifications, deletions, or as a direct result of mutations, has been closely linked to the development and progression of a wide range of cancers. Moreover, this pathway activation is a poor prognostic marker for many tumor types and confers resistance to various cancer therapies. Here, we describe VS-5584, a novel, low-molecular weight compound with equivalent potent activity against mTOR (IC(50) = 37 nmol/L) and all class I phosphoinositide 3-kinase (PI3K) isoforms IC(50): PI3Kα = 16 nmol/L; PI3Kß = 68 nmol/L; PI3Kγ = 25 nmol/L; PI3Kδ = 42 nmol/L, without relevant activity on 400 lipid and protein kinases. VS-5584 shows robust modulation of cellular PI3K/mTOR pathways, inhibiting phosphorylation of substrates downstream of PI3K and mTORC1/2. A large human cancer cell line panel screen (436 lines) revealed broad antiproliferative sensitivity and that cells harboring mutations in PI3KCA are generally more sensitive toward VS-5584 treatment. VS-5584 exhibits favorable pharmacokinetic properties after oral dosing in mice and is well tolerated. VS-5584 induces long-lasting and dose-dependent inhibition of PI3K/mTOR signaling in tumor tissue, leading to tumor growth inhibition in various rapalog-sensitive and -resistant human xenograft models. Furthermore, VS-5584 is synergistic with an EGF receptor inhibitor in a gastric tumor model. The unique selectivity profile and favorable pharmacologic and pharmaceutical properties of VS-5584 and its efficacy in a wide range of human tumor models supports further investigations of VS-5584 in clinical trials.


Subject(s)
Morpholines/pharmacology , Neoplasms/drug therapy , Phosphoinositide-3 Kinase Inhibitors , Protein Kinase Inhibitors/pharmacology , Purines/pharmacology , TOR Serine-Threonine Kinases/antagonists & inhibitors , Animals , Cell Line, Tumor , Cell Proliferation/drug effects , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/enzymology , Disease Models, Animal , Female , Gastrointestinal Neoplasms/drug therapy , Gastrointestinal Neoplasms/enzymology , Humans , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Mice, SCID , Morpholines/adverse effects , Morpholines/pharmacokinetics , Neoplasms/enzymology , PTEN Phosphohydrolase/deficiency , Prostatic Neoplasms/drug therapy , Prostatic Neoplasms/enzymology , Protein Kinase Inhibitors/adverse effects , Protein Kinase Inhibitors/pharmacokinetics , Purines/adverse effects , Purines/pharmacokinetics , Signal Transduction , Xenograft Model Antitumor Assays
16.
J Leukoc Biol ; 89(5): 707-20, 2011 May.
Article in English | MEDLINE | ID: mdl-21330351

ABSTRACT

CD137L (4-1BBL) is a member of the TNFSF and is expressed on APCs as a transmembrane protein. Reverse signaling by CD137L in monocytes causes cell activation and differentiation to mature inflammatory DCs that can stimulate T cell proliferation. However, CD137L agonists have also been reported to induce apoptosis in PBMCs. This study aimed at clarifying these seemingly opposing activities. We find that the dying cells within PBMCs are T cells and that this T cell death is dependent on monocytes and correlates with the monocyte:T cell ratio. This CD137L-induced, monocyte-mediated T cell apoptosis is reminiscent of MDCD, and both are cell contact-dependent. T cell death is not mediated by CD95 or DR4 or -5 but by ROS produced by the T cells. T cell apoptosis is restricted to the first 24 h of stimulation, and at later time-points, the monocytes differentiate to inflammatory DCs under the influence of CD137L signaling and acquire the capacity to stimulate T cell proliferation from Day 4 onward. This biphasic activity may contribute to infection-induced T cell attrition, where in the early phase (<24 h) of an infection, massive T cell apoptosis occurs before the antigen-specific T cells expand.


Subject(s)
4-1BB Ligand/metabolism , Apoptosis , Cell Proliferation , Monocytes/metabolism , T-Lymphocytes/cytology , Blotting, Western , Cell Adhesion , Cell Differentiation , Cell Movement , Flow Cytometry , Humans , Lymphocyte Activation , Monocytes/immunology , Reactive Oxygen Species/metabolism , Signal Transduction , Tumor Necrosis Factor Receptor Superfamily, Member 9/metabolism
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