scholarly journals Ranking small molecules by how much they preferentially inhibit the growth of cancer cell lines with either BRAF or KRAS oncogene mutations

2014 ◽  
Author(s):  
James Langham
Keyword(s):  
Growth Inhibition ◽  
Small Molecules ◽  
Cell Line ◽  
Cell Lines ◽  
Small Molecule ◽  
Molecular Mechanisms ◽  
Braf Inhibitor ◽  
Data Set ◽  
Cytidine Analogs ◽  
Knowledge Of Cancer

We were interested in the question of whether it might be possible to use knowledge of cancer-related mutations in the cell lines of the NCI60 screening data set to identify small molecules that preferentially inhibit the growth of cell lines containing either BRAF or KRAS oncogene mutations. Our hypothesis was that this cell line mutation knowledge could help to identify small molecules that were more likely to preferentially inhibit growth of cell lines with a particular mutation. It seems that any such molecules might be further investigated to try to better understand the molecular mechanisms of growth inhibition. We defined a quantity, \(\text{Diff}_{\text{mut}}\), that estimates how much more a given small molecule inhibits cell lines with a mutation of interest than cell lines without that mutation. We ranked the small molecules in descending order of \(\text{Diff}_{\text{mut}}\) and then tried to explain whether the ranking of the highest ranked molecules made sense in terms of independent facts about these molecules. This method showed the BRAF inhibitor vemurafenib to be highly ranked in the BRAF ranking. The cytidine analog cytarabine was found to be highly ranked in the KRAS ranking. Other cytidine analogs were also found to be highly ranked with respect to KRAS.

scholarly journals Ranking small molecules by how much they preferentially inhibit the growth of cancer cell lines with either BRAF or KRAS oncogene mutations

2014 ◽  
Author(s):  
James Langham
Keyword(s):  
Growth Inhibition ◽  
Small Molecules ◽  
Cell Line ◽  
Cell Lines ◽  
Small Molecule ◽  
Molecular Mechanisms ◽  
Braf Inhibitor ◽  
Data Set ◽  
Cytidine Analogs ◽  
Knowledge Of Cancer

We were interested in the question of whether it might be possible to use knowledge of cancer-related mutations in the cell lines of the NCI60 screening data set to identify small molecules that preferentially inhibit the growth of cell lines containing either BRAF or KRAS oncogene mutations. Our hypothesis was that this cell line mutation knowledge could help to identify small molecules that were more likely to preferentially inhibit growth of cell lines with a particular mutation. It seems that any such molecules might be further investigated to try to better understand the molecular mechanisms of growth inhibition. We defined a quantity, \(\text{Diff}_{\text{mut}}\), that estimates how much more a given small molecule inhibits cell lines with a mutation of interest than cell lines without that mutation. We ranked the small molecules in descending order of \(\text{Diff}_{\text{mut}}\) and then tried to explain whether the ranking of the highest ranked molecules made sense in terms of independent facts about these molecules. This method showed the BRAF inhibitor vemurafenib to be highly ranked in the BRAF ranking. The cytidine analog cytarabine was found to be highly ranked in the KRAS ranking. Other cytidine analogs were also found to be highly ranked with respect to KRAS.

Niche-Based Screening Identifies Novel Small Molecules That Overcome Stromal Effects in Multiple Myeloma

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 571-571
Author(s):  
Shrikanta Chattopadhyay ◽  
Alison L. Stewart ◽  
Siddhartha Mukherjee ◽  
Cherrie Huang ◽  
Kimberly A. Hartwell ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Drug Discovery ◽  
Small Molecules ◽  
Cell Line ◽  
Cell Lines ◽  
Small Molecule ◽  
Research Funding ◽  
Small Molecule Inhibitors ◽  
Novel Therapeutic

Abstract Abstract 571 Despite advances in the treatment of multiple myeloma (MM), this disease remains incurable and novel therapeutic strategies are urgently needed. Ideal strategies would overcome resistance factors from the bone-marrow microenvironment (niche) since a variety of inhibitors are rendered less effective by bone-marrow stromal cells (BMSCs) of the MM niche (McMillin et al., Nat Med. 2010 Apr;16(4):483–9). Drug discovery often entails a target-based approach but identifying targets in MM is challenging because of its complex genome and multiple niche interactions. We used a chemical biology approach in which small-molecule inhibitors of MM cells, grown within their niche, are first identified and then used to discover targets within MM or its niche. These compounds also serve as leads for future drug discovery. To model myeloma/niche interactions, we chose an MM cell line MOLP5 that has an obligate dependence on BMSCs to maintain viability. Small-molecule inhibitors were identified by screening ∼25,000 structurally diverse small molecules on GFP-labeled MOLP5 cells co-cultured with primary BMSCs derived from hip replacement samples. MOLP5 growth inhibition was measured by quantifying GFP(+) cells with automated high-throughput microscopy. About 800 hits were counter-screened on BMSCs alone to exclude non-specifically toxic compounds. The remaining 182 MOLP5-selective inhibitors were then tested on 2 other GFP-labeled MM cell-lines, MM1S and INA6, in the presence or absence of BMSCs to exclude compounds that are less effective in the presence of BMSCs. The 64 compounds that overcome BMSC resistance were tested on CD34+ human hematopoietic progenitors to prioritize compounds with selectivity between MM and normal blood cells. The 8 compounds that met these criteria fell into 3 categories: 1) compounds with equal activity in the presence or absence of BMSCs (overcome stromal resistance); 2) compounds with selectivity for BMSC-dependent MOLP5 cells (block stromal viability factors); and 3) compounds with increased activity in the presence of BMSCs (enhance stromal inhibitory factors). Because most efficacious clinical compounds like bortezomib act like compounds in category 1, compound BRD9876 was chosen from this category for mechanistic studies. Gene-expression profiling of BRD9876-treated MM1S cells suggested possible links to mitotic arrest and cell cycle analyses revealed a rapid accumulation of cells in the G2/M phase. Treated cells were stained for the mitotic spindle protein α-tubulin and found to exhibit an aberrant mono-astral mitotic phenotype, reminiscent of the kinesin-5 (Eg5; KIF11) inhibitor monastrol. This was encouraging because a kinesin-5 inhibitor ARRY-520 has shown promising durable responses in multiple myeloma (Shah et al, ASH Annual Meeting 2011; Abstract 1860). To determine if BRD9876 was a kinesin-5 inhibitor, a BRD9876-resistant sub-line of MM1S was developed and the kinesin-5 gene sequenced. BRD9876-resistant cells have a novel kinesin-5 mutation (Y104C) at a site that is distant from the monastrol-binding pocket. Most kinesin-5 inhibitors in clinical development bind the monastrol pocket, and the BRD9876-resistant cells were not cross-resistant to one such inhibitor, ispinesib, suggesting a distinct mode of kinesin-5 inhibition by BRD9876. To identify biomarkers of sensitivity to BRD9876, quantitative dose/response measurements in 98 genetically characterized cell lines (Schreiber & co-workers, submitted) comprising a subset of the Cancer Cell Line Encyclopedia (CCLE) were analyzed. Unbiased analyses correlating genetic features with sensitivity revealed that mutations in the mitotic regulator WEE1 were associated with sensitivity to BRD9876. Validation studies comparing WEE1 mutant to wild-type cell lines confirmed enhanced sensitivity of mutant cells to both BRD9876 and ispinesib suggesting that WEE1 mutations could be a useful biomarker for different kinesin-5 inhibitors. In contrast, co-treatment of WEE1 WT cells with sub-toxic concentrations of the WEE1 inhibitor MK1775 led to marked enhancement of BRD9876 activity but had little effect on ispinesib activity, suggesting a unique synergistic relationship between WEE1 inhibitors and BRD9876. In summary, niche-based screening in multiple myeloma has revealed a novel therapeutic candidate and can complement other drug-discovery approaches against this disease. Disclosures: Ebert: Celgene: Consultancy; Genoptix: Consultancy. Raje:Onyx: Consultancy; Celgene: Consultancy; Millennium: Consultancy; Acetylon: Research Funding; Amgen: Research Funding; Eli-Lilly: Research Funding.

scholarly journals Molecular analysis of ethyl methanesulfonate-induced reversion of a chromosomally integrated mutant shuttle vector gene in mammalian cells.

1988 ◽  
Vol 8 (10) ◽  
pp. 4185-4189 ◽  
Author(s):  
J A Greenspan ◽  
F M Xu ◽  
R L Davidson
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Dna Sequences ◽  
Mammalian Cells ◽  
Molecular Mechanisms ◽  
Shuttle Vector ◽  
Ethyl Methanesulfonate ◽  
Wild Type ◽  
Single Base ◽  
Type Sequence

The molecular mechanisms of ethyl methanesulfonate-induced reversion in mammalian cells were studied by using as a target a gpt gene that was integrated chromosomally as part of a shuttle vector. Murine cells containing mutant gpt genes with single base changes were mutagenized with ethyl methanesulfonate, and revertant colonies were isolated. Ethyl methanesulfonate failed to increase the frequency of revertants for cell lines with mutant gpt genes carrying GC----AT transitions or AT----TA transversions, whereas it increased the frequency 50-fold to greater than 800-fold for cell lines with mutant gpt genes carrying AT----GC transitions and for one cell line with a GC----CG transversion. The gpt genes of 15 independent revertants derived from the ethyl methanesulfonate-revertible cell lines were recovered and sequenced. All revertants derived from cell lines with AT----GC transitions had mutated back to the wild-type gpt sequence via GC----AT transitions at their original sites of mutation. Five of six revertants derived from the cell line carrying a gpt gene with a GC----CG transversion had mutated via GC----AT transition at the site of the original mutation or at the adjacent base in the same triplet; these changes generated non-wild-type DNA sequences that code for non-wild-type amino acids that are apparently compatible with xanthine-guanine phosphoribosyltransferase activity. The sixth revertant had mutated via CG----GC transversion back to the wild-type sequence. The results of this study define certain amino acid substitutions in the xanthine-guanine phosphoribosyltransferase polypeptide that are compatible with enzyme activity. These results also establish mutagen-induced reversion analysis as a sensitive and specific assay for mutagenesis in mammalian cells.

scholarly journals Proton-irradiated breast cells: molecular points of view

2019 ◽  
Vol 60 (4) ◽  
pp. 451-465 ◽  
Author(s):  
Valentina Bravatà ◽  
Francesco P Cammarata ◽  
Luigi Minafra ◽  
Pietro Pisciotta ◽  
Concetta Scazzone ◽  
...  
Keyword(s):  
Cell Line ◽  
Cell Fate ◽  
Cell Lines ◽  
Molecular Mechanisms ◽  
Proton Irradiation ◽  
Expression Profiles ◽  
Treatment Plan ◽  
Mcf10a Cell ◽  
Specific Cell ◽  
Dose Dependent

Abstract Breast cancer (BC) is the most common cancer in women, highly heterogeneous at both the clinical and molecular level. Radiation therapy (RT) represents an efficient modality to treat localized tumor in BC care, although the choice of a unique treatment plan for all BC patients, including RT, may not be the best option. Technological advances in RT are evolving with the use of charged particle beams (i.e. protons) which, due to a more localized delivery of the radiation dose, reduce the dose administered to the heart compared with conventional RT. However, few data regarding proton-induced molecular changes are currently available. The aim of this study was to investigate and describe the production of immunological molecules and gene expression profiles induced by proton irradiation. We performed Luminex assay and cDNA microarray analyses to study the biological processes activated following irradiation with proton beams, both in the non-tumorigenic MCF10A cell line and in two tumorigenic BC cell lines, MCF7 and MDA-MB-231. The immunological signatures were dose dependent in MCF10A and MCF7 cell lines, whereas MDA-MB-231 cells show a strong pro-inflammatory profile regardless of the dose delivered. Clonogenic assay revealed different surviving fractions according to the breast cell lines analyzed. We found the involvement of genes related to cell response to proton irradiation and reported specific cell line- and dose-dependent gene signatures, able to drive cell fate after radiation exposure. Our data could represent a useful tool to better understand the molecular mechanisms elicited by proton irradiation and to predict treatment outcome

scholarly journals Implementation of the NCI-60 Human Tumor Cell Line Panel to Screen 2260 Cancer Drug Combinations to Generate >3 Million Data Points Used to Populate a Large Matrix of Anti-Neoplastic Agent Combinations (ALMANAC) Database

2018 ◽  
Vol 24 (3) ◽  
pp. 242-263 ◽  
Author(s):  
David A. Close ◽  
Allen Xinwei Wang ◽  
Stanton J. Kochanek ◽  
Tongying Shun ◽  
Julie L. Eiseman ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Growth Inhibition ◽  
Cell Line ◽  
Cell Lines ◽  
Cancer Cell ◽  
Cancer Cell Lines ◽  
Cancer Drug ◽  
Large Matrix ◽  
Data Points

Animal and clinical studies demonstrate that cancer drug combinations (DCs) are more effective than single agents. However, it is difficult to predict which DCs will be more efficacious than individual drugs. Systematic DC high-throughput screening (HTS) of 100 approved drugs in the National Cancer Institute’s panel of 60 cancer cell lines (NCI-60) produced data to help select DCs for further consideration. We miniaturized growth inhibition assays into 384-well format, increased the fetal bovine serum amount to 10%, lengthened compound exposure to 72 h, and used a homogeneous detection reagent. We determined the growth inhibition 50% values of individual drugs across 60 cell lines, selected drug concentrations for 4 × 4 DC matrices (DCMs), created DCM master and replica daughter plate sets, implemented the HTS, quality control reviewed the data, and analyzed the results. A total of 2620 DCMs were screened in 60 cancer cell lines to generate 3.04 million data points for the NCI ALMANAC (A Large Matrix of Anti-Neoplastic Agent Combinations) database. We confirmed in vitro a synergistic drug interaction flagged in the DC HTS between the vinca-alkaloid microtubule assembly inhibitor vinorelbine (Navelbine) tartrate and the epidermal growth factor-receptor tyrosine kinase inhibitor gefitinib (Iressa) in the SK-MEL-5 melanoma cell line. Seventy-five percent of the DCs examined in the screen are not currently in the clinical trials database. Selected synergistic drug interactions flagged in the DC HTS described herein were subsequently confirmed by the NCI in vitro, evaluated mechanistically, and were shown to have greater than single-agent efficacy in mouse xenograft human cancer models. Enrollment is open for two clinical trials for DCs that were identified in the DC HTS. The NCI ALMANAC database therefore constitutes a valuable resource for selecting promising DCs for confirmation, mechanistic studies, and clinical translation.

scholarly journals Preclinical Activity of the MPS1 Inhibitor S81694 in Acute Lymphoblastic Leukemia (ALL)

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2631-2631
Author(s):  
Anna Kaci ◽  
Emilie Adiceam ◽  
Melanie Dupont ◽  
Marine Garrido ◽  
Jeannig Berrou ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Line ◽  
Solid Tumors ◽  
Cell Lines ◽  
Small Molecule ◽  
Research Funding ◽  
Lymphoblastic Leukemia ◽  
Jurkat Cells ◽  
Cell Cycle Distribution ◽  
Monopolar Spindle

Introduction: The dual-specificity protein kinase, monopolar spindle 1 (Mps1) is one the main kinases of the spindle assembly checkpoint (SAC) critical for accurate segregation of sister chromatids during mitosis. A hallmark of cancer cells is chromosomal instability caused by deregulated cell cycle checkpoints and SAC dysfunction. Mps1 is known to be overexpressed in several solid tumors including triple negative breast cancer. Thus, Mps1 seems to be a promising target and small molecules targeting Mps1 entered clinical trials in solid tumors. ALL originates from malignant transformation of B-and T-lineage lymphoid precursors with a variety of genetic aberrations including chromosome translocations, mutations, and aneuploidies in genes responsible for cell cycle regulation and lymphoid cell development. While outcome is excellent for pediatric patients and younger adults, relapsed and refractory disease still remain a clinical challenge for elder patients. Here, we demonstrate for the first time preclinical efficacy of the small molecule Mps1 inhibitor (Mps1i) S81694 in T- and B- ALL cells including BCR-ABL1+-driven B-ALL. Materials and Methods: Expression of Mps1 was determined by RT-qPCR and WB in JURKAT, RS4-11 and BCR-ABL1+ cells (BV-173 and TOM-1). A small molecule Mps1i (S81694) was tested alone (0 to 1000nM) or in combination with imatinib, dasatinib, nilotinib and ponatinib in BCR-ABL1+ ALL cell lines. Cell viability and IC50 was assessed by MTS assays after exposure to Mps1i for 72h. In combination experiments, compounds were added simultaneously and relative cell numbers were determined at 72h with MTS assays and combination index (CI) values were calculated according to the Bliss model. Induction of apoptosis was evaluated by annexin-V exposure and PI incorporation at 72h with increasing doses of Mps1i. Cell-cycle distribution was determined by cytofluorometric analysis detecting nuclear propidium iodide (PI) intercalation at 48h. Phosphorylation of Mps1 was detected in synchronized (by nocodazole and MG-132) cells by immunofluorescence using an anti phospho-Mps1 antibody detecting Thr33/Ser37 residues. Time-lapse microscopy was used in cell lines in presence or absence of S81694 to determine mitosis duration. Bone marrow (BM) nucleated patient cells were obtained after informed consent and incubated in methylcellulose with cytokines with or without Mps1i for 2 weeks to determine colony growth. Results: Expression of Mps1 could be detected by RT-qPCR and at the protein level by WB in all cell lines (Figure 1A and B ). IC50 after Mps1i exposure alone was 126nM in JURKAT cells, 51nM in RS4-11 cells, 75nM in BV-173 cells and 83nM in TOM-1. Significant apoptosis as detected by phosphatidylserine exposure and PI incorporation in all cell lines with BCR-ABL1+ cell lines BV-173 and TOM-1 cells being the most sensitive (80% and 60% apoptotic cells respectively)(Figure 1C). Upon Mps1i exposure we observed targeted inhibition of Mps1 phosphorylation at Thr33/Ser37 residues indicating the specific on target effect of S81694 by inhibiting Mps1 autophosphorylation (Figure 1D and E). Cell cycle profile was generally lost after treatment with S81694 in all cell lines indicating aberrant 2n/4n distribution due to SAC abrogation (Figure 1F). Furthermore, we demonstrated that S81694 exposure accelerated significantly mitosis in BV-173 cell line from 36 minutes to 19 minutes indicating effective inhibition of SAC function (Figure 1G). Interestingly, S81694 induced significant apoptosis (70%) in the imatinib resistant BV173 cell line bearing the E255K-BCR-ABL1-mutation. Combination of S81694 with TKI imatinib, dasatinib and nilotinib (but not ponatinib) was strongly synergistic in BCR-ABL1+ cells (Figure 1H). Finally, we observed inhibition of colony formation in a patient with BCR-ABL1+ B-ALL after exposure to 100nM and 250nM S81694 (reduction of 85% and 100% respectively)(Figure 1I). Conclusion: Mps1i S81694 yields significant preclinical activity in T-and B-cell ALL including BCR-ABL1+ models. Interestingly S81694 was efficacious in a TKI resistant cell line. Disclosures Kaci: Institut de Recherches Internationales Servier (IRIS): Employment. Garrido:Institut de Recherches Internationales Servier (IRIS): Employment. Burbridge:Institut de Recherches Internationales Servier (IRIS): Employment. Dombret:AGIOS: Honoraria; CELGENE: Consultancy, Honoraria; Institut de Recherches Internationales Servier (IRIS): Research Funding. Braun:Institut de Recherches Internationales Servier (IRIS): Research Funding.

Unravelling the mechanisms underpinning chemokine receptor activation and blockade by small molecules: a fine line between agonism and antagonism?

2007 ◽  
Vol 35 (4) ◽  
pp. 755-759 ◽  
Author(s):  
E. Wise ◽  
J.E. Pease
Keyword(s):  
Small Molecules ◽  
Small Molecule ◽  
Chemokine Receptor ◽  
Chemokine Receptors ◽  
Molecular Mechanisms ◽  
Receptor Activation ◽  
G Protein Coupled Receptors ◽  
Considerable Effort ◽  
G Protein Coupled ◽  
Migration Of Cells

Chemokines are a family of small basic proteins which induce the directed migration of cells, notably leucocytes, by binding to specific GPCRs (G-protein-coupled receptors). Both chemokines and their receptors have been implicated in a host of clinically important diseases, leading to the notion that antagonism of the chemokine–chemokine receptor network may be therapeutically advantageous. Consequently, considerable effort has been put into the development of small-molecule antagonists of chemokine receptors and several such compounds have been described in the literature. One curious by-product of this activity has been the description of several small-molecule agonists of the receptors, which are typically discovered following the optimization of lead antagonists. In this review we discuss these findings and conclude that these small-molecule agonists might be exploited to further our understanding of the molecular mechanisms by which chemokine receptors are activated.

Effects of rmhTRAIL Combined with Daunorubicin in Inducing Apoptosis of Leukemia Cell Lines and Its Mechanism.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1986-1986
Author(s):  
Xuejun Zhang ◽  
Li Wen ◽  
Fuxu Wang ◽  
Ling Pan ◽  
Jianmin Luo ◽  
...  
Keyword(s):  
Growth Inhibition ◽  
Cell Line ◽  
Cell Lines ◽  
Mrna Level ◽  
Leukemia Cell ◽  
K562 Cells ◽  
Expression Level ◽  
U937 Cells ◽  
Leukemia Cell Lines ◽  
Before And After

Abstract Tumor Necrosis factor (TNF)-related apoptosis- inducing ligand (TRAIL) is a new member of TNF superfamily discovered recently. Several studies showed that TRAIL can preferentially induce apoptosis in a variety of tumor cells, while most normal cells tested do not appear to be sensitive to TRAIL. In the present study, we treated K562 and U937 leukemia cell lines with recombinant mutant human TRAIL (rmhTRAIL) alone or together with daunorubicin (DNR) to investigate the apoptosis of the treated cells and the synergistic reaction of rmhTRAIL and DNR. The normal cell line MRC-5 was used as control. The expression of four TRAIL receptors mRNA (death receptor DR4 and DR5, decoy receptor DcR1 and DcR2) in the cells lines were detected before and after the treatment by DNR. (1) AO-EB double staining and TUNEL staining were used to evaluate the morphological change of leukemia cell lines before and after the treatment. The results showed that rmhTRAIL could induce the apoptosis of leukemia cell lines and a dose-dependent manner was found in leukemia cell lines but not in MRC-5 cell lines. (2) The growth inhibition rate of leukemia cell lines induced by rmhTRAIL alone or combined with DNR was examined with MTT assays. Different concentrations of rmhTRAIL(8, 40, 200, 1000ng/mL)alone or combined with DNR(8, 40, 200, 1000ng/mL) was used. The result showed a dose-dependent growth inhibition by rmhTRAIL alone for K562- and U937-cell line (P<0.05) also, but not for MRC-5 cell line (P>0.05). The IC50 for K562 cells and for U937 cells had no statistic difference (538.80 vs 301.56ng/mL, P>0.05). In leukemia cell lines, the growth inhibition rates in combination groups were much higher than in rmhTRAIL or DNR alone groups (P<0.05), and no synergistic killing effects was found in MRC-5 cells (P<0.05). It was concluded that rmhTRAIL had synergistic effects with DNR in the growth inhibition of K562 and U937 cells. (3). To explore the antitumor mechanisms of rmhTRAIL combined with DNR, the expression level of the DR4, DR5 and DcR1, DcR2 mRNA in these three cell lines was examined by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) before and after the treatment with DNR. The high expression of DR4,DR5 mRNA in the tested cells were observed before the treatment of DNR, while very low or even undetectable expression level of DcR1 and DcR2 mRNA were observed in U937 and K562 cells, and a high expression level of DcR1 and DcR2 mRNA in MRC-5 cells were observed. After 24 hours treatment of three cell lines with DNR (200ng/ml), the expression level of DR5 mRNA increased in K562 and U937 cells (P<0.05). DR4 mRNA also increased in K562 cells but not in U937 cells. There was no change in DcR1 and DcR2 mRNA level in three cell lines. The four receptors’ mRNA level in MRC-5 cells was not influenced by DNR. Our results indicated that rmhTRAIL could induce the apoptosis of leukemia cell lines, and DNR could enhance significantly the sensitivity of K562 and U937 cells to apoptosis induced by rmhTRAIL through up-regulation of death receptors. Therefore, we presumed TRAIL might be act as a new agent for biological therapy in leukemia.

Targeting Myeloproliferative Diseases with JAK2 Inhibitors.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3550-3550
Author(s):  
Vadim Markovtsov ◽  
Diane Yu ◽  
Marina Gelman ◽  
Wayne Lang ◽  
Vanessa C. Taylor ◽  
...  
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Cell Activation ◽  
Molecular Mechanisms ◽  
Mutant Cell ◽  
Control Cell ◽  
Mast Cell Activation ◽  
Kinase Gene ◽  
Myeloproliferative Diseases ◽  
Jak2 Inhibitors

Abstract Limited options provided by the current standard of care for the patients suffering from myeloproliferative diseases (MPDs) prompted an extensive search for the underlying molecular mechanisms of these disorders. Recent discovery of a single activating mutation (V617F) in JAK2 kinase gene associated with the development of the polycythemia vera (PV), essential thrombocythemia (ET) and chronic idiopathic myelofibrosis (CIMF) opened up a possibility to develop highly targeted therapies against these debilitating ailments. To that end, we engineered cytokine-independent Ba/F3 cell line expressing the V617F mutant of JAK2 to screen a focused small molecule library for potential inhibitors of JAK2 V617F -dependent proliferation. We confirmed the ability of hit compounds to inhibit proliferation of JAK2-dependent tumor cell lines using UKE-1 and SET-2 cells carrying the V617F JAK2 mutation. A FACS-based phosphoSTAT5 assay was then used to demonstrate that the hits directly targeted mutant JAK2. JAK3 activity of each compound was evaluated in IL-2-dependent CTLL-2 cell line using phosphoSTAT5 FACS and proliferation assays. To avoid hits with nonspecific antiproliferative activity, the hits were tested in JAK2-independent MOLT4, A549 and H1299 cell lines. Compound hits with the desirable properties were further evaluated for their ability to inhibit JAK2, JAK3 and other kinases in the context of T cell, B cell, or mast cell activation using a variety of cell-based assays as well as in the in vitro biochemical assays. We identified a number of compounds that potently inhibit growth of the two V617F mutant cell lines with EC50s varying from 20 to 500 nM, but do not affect proliferation of control cell lines MOLT4, A549 and H1299 to the same degree. These compounds induce strong and highly specific suppression of STAT5 phosphorylation with IC50s of 10 to 200 nM in SET-2 and V617F JAK2 expressing Ba/F3 cells. One of the hits with the desirable biological and pharmacokinetic profiles was further evaluated in V617F JAK2 Ba/F3 engraftment mouse model where it demonstrated significant extension of survival at 150 and 200 mg/kg bid. Such potent JAK2 inhibitors could become the basis for the next generation of compounds targeting JAK2-dependent myeloproliferative diseases.

A Novel Pan-PI3K/Akt Inhibitor, SF1126, Inhibits In Vitro Growth of Multiple Myeloma Cells.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4806-4806
Author(s):  
Jeannine Silberman ◽  
Kimberly Dalbey ◽  
Claire Torre ◽  
Ebenezer David ◽  
Leif Bergsagel ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Cell Death ◽  
Growth Inhibition ◽  
Cell Line ◽  
Cell Lines ◽  
Mtt Assay ◽  
Immunoblot Analysis ◽  
Akt Inhibitor ◽  
Downstream Targets

Abstract Backround: Dysregulation of the PI3K/Akt signal transduction pathway has been implicated in the development of a number of malignancies, including multiple myeloma (MM). This cellular signaling mechanism and its downstream targets (eg mTOR) regulate cell growth, proliferation and apoptosis. SF1126 (Semafore) is a water soluble prodrug of the pan-PI3K inhibitor, LY294002, whose anti-proliferative and pro-apoptotic activity has been well described in the literature. Preclinical studies using SF1126 in a variety of malignancies including glioma, prostate, non-small cell lung cancer, and breast cancer appear promising and have demonstrated profound antiangiogenic effects mediated through VEGF inhibition. Aim: To demonstrate in vitro anti-myeloma activity of SF1126, alone and in combination with dexamethasone, bortezomib, and melphalan and evaluate their effects on downstream targets of PI3K/Akt. Methods: MM cell lines (MM.1R, MM.1S, RPMI 8226) were treated with SF1126 (1–100uM), dexamethasone (5uM), bortezomib (5nM), melphalan (10uM) alone, and in combination. Growth inhibition following treatment was measured by MTT assay at 24 and 48 hours. Apoptosis was assessed by annexin-V binding assay using flow cytometry. Immunoblot analysis was performed to measure downstream targets of Akt including: p-PDK1 and mTOR (4E-BP1). Results: A clear dose response was established with an IC50 of 8.75uM in the MM.1R and 7.5uM in the MM.1S cell lines at 48 hours. At 24 and 48 hours, 5uM SF1126 alone resulted in 80% and 64% cell viability by MTT assay, respectively, in the MM.1R cell line. The combination of 5uM SF1126 with conventional agents was then tested in the MM.1R cell line. Combination with 5uM dexamethasone enhanced the efficacy of 5uM SF1126 by 26% at 48 hours. Combination with 10uM melphalan enhanced the efficacy of 5uM SF1126 by 20% at 24 hours. The combination with 5nM bortezomib enhanced the efficacy of 5uM SF1126 by 23% at 48 hours. Given prior experience demonstrating that short exposure to bortezomib activates Akt, we tested sequential administration of bortezomib and SF1126 in the MM.1R cell line. Optimal cell death was induced with bortezomib prior to SF1126, followed by concurrent administration. Immunoblot analysis of p-PDK1, downstream mTOR target (4E-BP1) were performed on the MM.1S cell line treated with 5, 10, 20, and 50uM SF1126 at 12 and 24 hours. At the 12 hour time point, p-PDK-1 appeared to increase, but was significantly reduced by 48 hours. A similar pattern of initial upregulation followed by reduction by 24 hours was seen with the mTOR protein 4E-BP1. Conclusion: SF1126 has dose dependent, in vitro activity in several multiple myeloma cell lines both as a single agent and in combination with dexamethasone, bortezomib, and melphalan. The addition of SF1126 to dexamethasone in a dexamethasone resistant cell line results in increased cell death, possibly by overcoming resistance mechanisms. The addition of SF1126 to bortezomib and melphalan also resulted in increased growth inhibition over either agent alone. These results warrant further study of this promising new pan-PI3K/Akt inhibitor.

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