Abstract The proto-oncogene proviral integration site for moloney murine leukemia virus (PIM) kinases (PIM-1, PIM-2, and PIM-3) are serine/threonine kinases that are involved in a number of signaling ...pathways important to cancer cells. PIM kinases act in downstream effector functions as inhibitors of apoptosis and as positive regulators of G1 -S phase progression through the cell cycle. PIM kinases are upregulated in multiple cancer indications, including lymphoma, leukemia, multiple myeloma, and prostate, gastric, and head and neck cancers. Overexpression of one or more PIM family members in patient tumors frequently correlates with poor prognosis. The aim of this investigation was to evaluate PIM expression in low- and high-grade urothelial carcinoma and to assess the role PIM function in disease progression and their potential to serve as molecular targets for therapy. One hundred thirty-seven cases of urothelial carcinoma were included in this study of surgical biopsy and resection specimens. High levels of expression of all three PIM family members were observed in both noninvasive and invasive urothelial carcinomas. The second-generation PIM inhibitor, TP-3654, displays submicromolar activity in pharmacodynamic biomarker modulation, cell proliferation studies, and colony formation assays using the UM-UC-3 bladder cancer cell line. TP-3654 displays favorable human ether-à-go-go-related gene and cytochrome P450 inhibition profiles compared with the first-generation PIM inhibitor, SGI-1776, and exhibits oral bioavailability. In vivo xenograft studies using a bladder cancer cell line show that PIM kinase inhibition can reduce tumor growth, suggesting that PIM kinase inhibitors may be active in human urothelial carcinomas.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The nuclease hypersensitivity element III 1 upstream of the P1 promoter of c- MYC controls 85–90% of the transcriptional activation of this gene. We have demonstrated that the purine-rich strand of ...the DNA in this region can form two different intramolecular G-quadruplex structures, only one of which seems to be biologically relevant. This biologically relevant structure is the kinetically favored chair-form G-quadruplex, which is destabilized when mutated with a single G → A transition, resulting in a 3-fold increase in basal transcriptional activity of the c- MYC promoter. The cationic porphyrin TMPyP4, which has been shown to stabilize this G-quadruplex structure, is able to suppress further c- MYC transcriptional activation. These results provide compelling evidence that a specific G-quadruplex structure formed in the c- MYC promoter region functions as a transcriptional repressor element. Furthermore, we establish the principle that c- MYC transcription can be controlled by ligand-mediated G-quadruplex stabilization.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Epithelial-mesenchymal transition (EMT) has been associated with metastatic spread and EGF receptor (EGFR) inhibitor resistance. We developed and validated a robust 76-gene EMT signature using gene ...expression profiles from four platforms using non-small cell lung carcinoma (NSCLC) cell lines and patients treated in the Biomarker-Integrated Approaches of Targeted Therapy for Lung Cancer Elimination (BATTLE) study.
We conducted an integrated gene expression, proteomic, and drug response analysis using cell lines and tumors from patients with NSCLC. A 76-gene EMT signature was developed and validated using gene expression profiles from four microarray platforms of NSCLC cell lines and patients treated in the BATTLE study, and potential therapeutic targets associated with EMT were identified.
Compared with epithelial cells, mesenchymal cells showed significantly greater resistance to EGFR and PI3K/Akt pathway inhibitors, independent of EGFR mutation status, but more sensitivity to certain chemotherapies. Mesenchymal cells also expressed increased levels of the receptor tyrosine kinase Axl and showed a trend toward greater sensitivity to the Axl inhibitor SGI-7079, whereas the combination of SGI-7079 with erlotinib reversed erlotinib resistance in mesenchymal lines expressing Axl and in a xenograft model of mesenchymal NSCLC. In patients with NSCLC, the EMT signature predicted 8-week disease control in patients receiving erlotinib but not other therapies.
We have developed a robust EMT signature that predicts resistance to EGFR and PI3K/Akt inhibitors, highlights different patterns of drug responsiveness for epithelial and mesenchymal cells, and identifies Axl as a potential therapeutic target for overcoming EGFR inhibitor resistance associated with the mesenchymal phenotype.
Lysine specific demethylase 1 (LSD1) plays an important role in regulating histone lysine methylation at residues K4 and K9 on histone H3 and is an attractive therapeutic target in multiple ...malignancies. Here we report a structure-based virtual screen of a compound library containing ∼2 million small molecular entities. Computational docking and scoring followed by biochemical screening led to the identification of a novel N′-(1-phenylethylidene)-benzohydrazide series of LSD1 inhibitors with hits showing biochemical IC50s in the 200–400 nM range. Hit-to-lead optimization and structure–activity relationship studies aided in the discovery of compound 12, with a K i of 31 nM. Compound 12 is reversible and specific for LSD1 as compared to the monoamine oxidases shows minimal inhibition of CYPs and hERG and inhibits proliferation and survival in several cancer cell lines, including breast and colorectal cancer. Compound 12 may be used to probe LSD1’s biological role in these cancers.
Targeting Axl and Mer kinases in cancer Verma, Anupam; Warner, Steven L; Vankayalapati, Hariprasad ...
Molecular cancer therapeutics
10, Issue:
10
Journal Article
Peer reviewed
Receptor tyrosine kinases (RTK) are cell-surface transmembrane receptors that contain regulated kinase activity within their cytoplasmic domain and play an important role in signal transduction in ...both normal and malignant cells. The mammalian TAM RTK family includes 3 closely related members: Tyro-3, Axl, and Mer. Overexpression or ectopic expression of the TAM receptors has been detected in a wide array of human cancers. Growth arrest-specific gene 6 has been identified as the major ligand for these TAM RTKs, and its binding to the receptors has been shown to promote proliferation and survival of cancer cells in vitro. Abnormal expression and activation of Axl or Mer can provide a survival advantage for certain cancer cells. Inhibition of Axl and Mer may enhance the sensitivity of cancer cells to cytotoxic agents and would potentially be a therapeutic strategy to target cancer cells. This review elucidates the role of Axl and Mer in normal cellular function and their role in oncogenesis. In addition, we review the potential to inhibit these RTKs for the development of therapeutic targets in treatment of cancer.
We identified an essential cell wall biosynthetic enzyme in Bacillus anthracis and an inhibitor thereof to which the organism did not spontaneously evolve measurable resistance. This work is based on ...the exquisite binding specificity of bacteriophage-encoded cell wall-hydrolytic lysins, which have evolved to recognize critical receptors within the bacterial cell wall. Focusing on the B. anthracis-specific PlyG lysin, we first identified its unique cell wall receptor and cognate biosynthetic pathway. Within this pathway, one biosynthetic enzyme, 2-epimerase, was required for both PlyG receptor expression and bacterial growth. The 2-epimerase was used to design a small-molecule inhibitor, epimerox. Epimerox prevented growth of several Gram-positive pathogens and rescued mice challenged with lethal doses of B. anthracis. Importantly, resistance to epimerox was not detected (<10(-11) frequency) in B. anthracis and S. aureus. These results describe the use of phage lysins to identify promising lead molecules with reduced resistance potential for antimicrobial development.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Methylation of CpG islands in promoter regions is often associated with gene silencing and aberrant DNA methylation occurs in most cancers, leading to the silencing of some tumor suppressor genes. ...Reversal of this abnormal hypermethylation by DNA methylation inhibitors is effective in reactivating methylation-silenced tumor suppressor genes both in vitro and in vivo. Several DNA methylation inhibitors have been well studied; the most potent among them is 5-aza-2'-deoxycytidine (5-Aza-CdR), which can induce myelosuppression in patients. S110 is a dinucleotide consisting of 5-Aza-CdR followed by a deoxyguanosine, which we previously showed to be effective in vitro as a DNA methylation inhibitor while being less prone to deamination by cytidine deaminase, making it a promising alternative to 5-Aza-CdR. Here, we show that S110 is better tolerated than 5-Aza-CdR in mice and is as effective in vivo in inducing p16 expression, reducing DNA methylation at the p16 promoter region, and retarding tumor growth in human xenograft. We also show that S110 is effective by both i.p. and s.c. deliveries. S110 therefore is a promising new agent that acts similarly to 5-Aza-CdR and has better stability and less toxicity.
A nanoparticle formulation of an Aurora B inhibitor increases antitumor efficacy and reduces toxicity, which may be a precedent for the use of this technology with other small molecules (Ashton et ...al., this issue).
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In this work, we describe the use of the rule of 3 fragment-based strategies from biochemical screening data of 1100 in-house, small, low molecular weight fragments. The sequential ...combination of in silico fragment hopping and fragment linking based on S160/Y161/A162 hinge residues hydrogen bonding interactions leads to the identification of novel 1H-benzodimidazol-2-yl)-1H-indazol class of Phosphoinositide-Dependent Kinase-1 (PDK1) inhibitors. Consequent SAR and follow-up screening data led to the discovery of two potent PDK1 inhibitors: compound 32 and 35, with an IC50 of 80 nM and 94 nM, respectively. Further biological evaluation showed that, at the low nanomolar concentration, the drug had potent ability to inhibit phosphorylation of AKT and p70S6, and selectively kill the cancer cells with mutations in both PTEN and PI3K. The microarray data showed that DUSP6, DUSP4, and FOSL1 were down-regulated in the sensitive cell lines with the compound treatment. The in vivo test showed that 35 can significantly inhibit tumor growth without influencing body weight growth. Our results suggest that these compounds, especially 35, merit further pre-clinical evaluation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Background The NLRP3 inflammasome is a multiprotein complex composed of several proteins, including NLRP3, ASC, Nek-7, and pro-caspase-1. Many immune cell populations express the NLRP3 inflammasome. ...In the presence of various exogenous stimuli such as lipopolysaccharide (LPS) or extracellular ATP, the NLRP3 inflammasome components assemble and become activated, releasing pro-inflammatory cytokines IL-1β and IL-18. One of the critical steps in inflammasome assembly is the recruitment of ASC and the formation of ASC protein aggregates called specks. These specks are large enough to be measured through microscopy, and the ASC speck count indicates NLRP3 activation. The release of IL-1β and IL-18 and the upregulation of NLRP3 inflammasome component genes have been observed in many inflammatory and hematological disorders, suggesting the NLRP3 pathway is involved in the disease pathogenesis of many diseases. Purpose HT-6184 is a small molecule that blocks the assembly of the NLRP3 inflammasome through allosteric binding to the protein Nek7. Here we demonstrate the ability of HT-6184 to modulate NLRP3 inflammasome formation by measuring ASC specks using a human monocytic THP-1 cell line engineered to express a GFP-labeled ASC protein. Methods THP1-ASC-GFP cells were cultured in RPMI 1640 with 10% heat-inactivated FBS, 100 μg/mL normocin, and 100 μg/mL Pen-Strep. Cells were seeded at 400,000 cells per well in a 96-well plate and left overnight. Cells were then treated with vehicle or LPS for 3 hours. Following LPS stimulation, cells were treated with vehicle or HT-6184 for 2 hours. After incubation, cells were treated with 5 μM Nigericin and imaged in 3-minute intervals for 1 hour. The images were analyzed for specks. Results By treating THP1-ASC-GFP with LPS and nigericin, we induced the formation of ASC specks and visualized them using fluorescent microscopy. Cells treated with 200 nM HT-6184 had significantly fewer ASC specks than the LPS and nigericin-treated control. ASC speck inhibition by HT-6184 was dose-dependent, as inhibition of speck formation decreased with lower doses of HT-6184. Conclusions HT-6184 effectively prevents the formation of ASC specks in THP-1-ASC-GFP cells. Since THP-1 cells are a monocytic cell line, this data suggests our ability to inhibit the NLRP3 pathway in hematological disorders effectively. By preventing inflammasome formation and activation, we expect to be able to reduce disease burden in hematological diseases.
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IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZRSKP
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