BACKGROUND:The Provirus integrating site Moloney murine leukemia virus (Pim) family are proteins with serine/threonine kinase activity. Studies have demonstrated overexpression of Pims in cancer. To our knowledge, only a single study has examined Pim-1 in urothelial carcinoma. The aim of this investigation was to evaluate Pim-1, Pim-2, and Pim-3 in urothelial carcinoma and assess for expression that may contribute to disease progression and serve as a site for targeted therapy.METHODS:This retrospective study included 137 cases taken from specimens from the University of Utah, Department of Pathology (2008 to 2011). Tissue was stained with antibodies against Pim-1, Pim-2, and Pim-3. Cases were classified into 3 groups, based upon current World Health Organization criteria (invasive high-grade urothelial carcinoma [IHG] [n=84], noninvasive high-grade urothelial carcinoma/carcinoma in situ [n=32], and noninvasive low-grade urothelial carcinoma [NILG] [n=21]). Cases were scored and recorded as positive or negative on the basis of the percentage of cells with cytoplasmic and/or nuclear staining.RESULTS:NILG showed higher expression of Pim-1 (relative expression rate [RER]=2.28; 95% confidence interval [CI], 0.183-0.764) and Pim-3 (RER=3.06; 95% CI, 0.423-0.816) compared with other lesions. IHG had lower expression of Pim-1 (RER=0.31; 95% CI, 0.401-0.844) and Pim-3 (RER=0.354; 95% CI, 0.322-0.816) and noninvasive high-grade urothelial carcinoma (NIHG) demonstrated increased expression of Pim-1 and (RER=2.09; 95% CI, 0.124-0.739) and Pim-2 (RER=1.70; 95% CI, 0.151-0.591). At least 1 Pim kinase protein was expressed at the following rates: 49% in IHG, 66% in NIHG, and 76% in NILG.CONCLUSION:A high percentage of urothelial carcinomas express Pim kinases. Pim expression differs in NILG, NIHG, and IHG lesions.

Abstract Lysine-specific demethylase 1 (LSD1/AOF2/KDM1A) is a flavin-dependent histone demethylase that catalyzes the posttranslational oxidative demethylation of mono- and dimethylated lysines on histones. Methylation of lysine residues on histones can signal transcriptional activation or repression depending on the specific residue involved. H3K4me2 is a transcription-activating mark, and demethylation of this mark by LSD1 prevents expression of tumor suppressor genes important in human cancer. Whereas, H3K9 methylation is a repressive mark and LSD1 activity has been shown to upregulate tumor promoting pathways. This makes LSD1 emerge as an important target for the development of novel antitumor inhibitors. The compound HCI-2577 was identified as a potent reversible inhibitor of LSD1 enzymatic activity, with an IC50 of 7nM. In a diverse cell screen panel for cellular viability, Ewing's sarcoma was identified as being sensitive to HCI-2577. Here we show that HCI-2577 is efficacious in in vivo models of Ewing's sarcoma as a single agent with a favorable drug profile. In conclusion, HCI-2577 is a novel LSD-1 inhibitor with therapeutic potential in Ewing's sarcoma demonstrating promising activity in biochemical, cell-based and in vivo assays. Citation Format: Jared J. Bearss, Adrianne Neiss, Xiao-Hui Liu, Hariprasad Vankayalapati, Sunil Sharma. HCI-2577 inhibits LSD1 and modulates histone marks in Ewing's sarcoma models. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C92.

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.

Abstract Pancreatic cancer is virtually a uniformly lethal disease and a better understanding of the molecular basis of this malignancy is needed to discover new ways to prevent or treat this deadly disease. A central feature of malignant cells is their ability to disseminate from the primary tumor and establish local and distant metastases. In most cases, cancer patients with localized disease have significantly better prognosis than those with metastatic tumors and the majority of cancer mortality is associated with metastatic disease rather than the primary tumor. The receptor tyrosine kinase Axl is overexpressed in over 50% of pancreatic cancers and expression of Axl in these cancers is highly associated with a poor prognostic outcome for patients. Axl is a TAM family receptor tyrosine kinase involved in multiple aspects of tumorigenesis. Increased expression of Axl is associated with increased oncogenic transformation, cell survival, proliferation, migration, angiogenesis, and cellular adhesion. The known ligand for Axl is the Growth Arrest Specific Gene-6 (Gas6) protein and it's binding to Axl leads to Axl autophosphorylation and activation of downstream signaling pathways including MAPK and PI3K/Akt pathways. We discovered and developed a small molecule Axl kinase inhibitor, HCI-2084, and explored it for the effectiveness of targeting the Axl kinase in cell-based models of pancreatic cancer. HCI-2084 is a 2-((2,5-substitutedpyrimidin-4-yl)amino)-N,N-dimethyl benzene sulfonamide that has low nanomolar (IC50 = 12 nM) activity against the Axl kinase in a biochemical assays. In further biochemical evaluation, HCI-2084 was shown to inhibit the entire TAM family of kinases (IC50 Axl = 12 nM; IC50 Mer = 60 nM; Tyro3 = 71% inhibition at 200 nM). HCI-2084 inhibits a small number of additional kinases when screened in a kinase panel of over 500 kinases and has demonstrated an ADMET profile suggesting it may be a potential clinical candidate. In cell proliferation assays, HCI-2084 significantly inhibited pancreatic cancer cell growth at concentrations as low as 30 nM. In pharmacodynamic assays, HCI-2084 dramatically inhibited Akt signaling (pAKT S473) downstream of GAS6 stimulation in pancreatic cancer cell lines. Consistent with the known function of Axl, HCI-2084 inhibited Gas6-induced migration and invasion of pancreatic cancer cells in vitro and potently induces apoptosis. Mechanistically, HCI-2084 decreases the expression of genes involved in Epithelial-Mesenchymal Transition (EMT) and induces cells to take on more epithelial phenotypes. HCI-2084 also significantly inhibited the growth of pancreatic cancer cell lines grown in xenograft tumor mouse model and taken together, these results suggest Axl is a potential therapeutic target in pancreatic cancer and that HCI-2084 is a potential agent treat this disease. Citation Format: Malia Anderson, Alex Ober, Alexis Mollard, Lee Call, Jared J. Bearss, Hariprasad Vankayalapati, Sunil Sharma, Steven Warner, David J. Bearss. Inhibition of the tyrosine kinase receptor Axl blocks cell invasion and promotes apoptosis in pancreatic cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5543. doi:10.1158/1538-7445.AM2013-5543

Abstract Multiple myeloma (MM) is a malignant disease that is characterized by an excess of monotypic plasma cells in the bone marrow (BM). A key clinical characteristic of MM is the localization of the MM cells to the bone marrow where they promote osteolytic bone destruction and impaired hematopoietic function. As a consequence MM patients experience bone pain, hypocalcaemia, anemia. Although there has been some progress in recent years in the development of novel drugs, such as proteasome inhibitors and derivatives of thalidomide, MM remains incurable and the majority of patients eventually succumb to their cancer. We have recently identified BTK over-expression in cancer cells taken from patients with multiple myeloma. In addition we have observed that BTK is also expressed in the activated osteoclasts of MM patients indicating that targeted inhibition of BTK might not only effect the MM cancer cells but may also influence the activity of osteoclasts and the associated osteolytic lesions. Bruton's tyrosine kinase (BTK) is a cytoplasmic nonreceptor tyrosine kinase belonging to the Tec family of kinases. BTK has been extensively studied for its role in B-cell maturation and activation of B-cells by various ligands is accompanied by the translocation of BTK to the cell membrane where it binds phosphatidylinositol-3,4,5-trisphosphate through its PH domain. Activation of BTK results in downstream signaling through the PI3K/AKT, PLCγ1/2, NFκB, and other signaling pathways important for B-cell development and function. We propose that BTK plays an important role in multiple myeloma pathophysiology and that therapeutically targeting BTK will inhibit the growth of cancer cells and alter the tumor microenvironment in the bone marrow of multiple myeloma cancer patients. Using a structure-based approach we have developed a series of irreversible BTK inhibitors with selective and potent low nanomolar activity. In preclinical studies to date, our compounds have demonstrated promising activity in biochemical and cell-based experiments. Our BTK-targeted agents have shown activity in MM cells and have good pharmacokinetics when delivered IV and oral. MM cells create an adverse microenvironment from a pathophysiologic and clinical perspective because of the disruption of bone remodeling and this disruption of normal bone function has been shown to inhibit the response of MM cell to drug treatment. Therefore, a strategy to develop new drugs for MM must take into account the ability of the new agents to partition and distribute to the bone and function in the bone microenviroment of MM. Our compounds are being optimized for their ability to partition to bone and remain active in the BM microenvironment. By inhibiting BTK we seek to block BTK-dependent growth and migration of multiple myeloma cells and inhibit of the production of differentiated activated osteoclasts thereby disrupting the bone marrow microenvironment in MM. Citation Format: Destinee Bushman, Jared J. Bearss, Venkataswamy Sorna, Hariprasad Vankayalapati, Sunil Sharma, Fenghuang Zhan, David Bearss. Targeting Bruton's tyrosine kinase (BTK) in multiple myeloma with novel BTK inhibitors. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2161. doi:10.1158/1538-7445.AM2013-2161

Abstract The proto-oncogene PIM kinases (PIM-1, PIM-2, PIM-3) are serine/threonine kinases that have been shown to be involved in a number of signaling pathways important to cancer cells. PIM kinases act as downstream effectors 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, prostate, gastric, and head & 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 for expression that may contribute to disease progression and serve as a potential site for targeted therapy. Seventy-two cases of urothelial carcinoma were included in this retrospective study of surgical biopsy and resection specimens from the University of Utah Department of Pathology (retrieved from 2008-2011). Tissue was stained with commercially available antibodies against PIM-1, PIM-2, and PIM-3. Cases were divided into three groups (invasive high grade urothelial carcinoma (n=49), non-invasive urothelial carcinoma/carcinoma in situ (n=16), and non-invasive low grade urothelial carcinoma (n=7)). Individual cases were then given a score (0-4) based upon a percentage of cells staining positive for each antibody (<5%=0; 5-25%=1; 26-50%=2; 51-75%=3; >75%=4). A score of 2 or greater was considered expressed. PIM-1, PIM-2 and PIM-3 expression was noted in 29% (2/7), 43% (3/7) and 86% (6/7) cases of non-invasive low-grade urothelial carcinoma; 44% (7/16), 50% (8/16), 44% (7/16) cases of non-invasive high-grade urothelial carcinoma; 10% (5/49), 27% (13/49), and 18% (9/49) cases of invasive high-grade urothelial carcinoma, respectively. These results suggest that expression of PIM-1, PIM-2 and PIM-3 is present in a significant percentage of urothelial carcinomas and may serve as a source for targeted PIM-kinase inhibition. We have developed PIM inhibitors exhibiting 4-10 fold improved potency against the PIM kinase family compared to our original PIM inhibitor SGI-1776. Our PIM inhibitors display sub-μM activity in pharmacodynamic marker modulation, proliferation and 2D colony formation assays using the UM-UC-3 bladder cancer cell line. These PIM kinase inhibitors also are potent inducers of apoptosis in T24, RT4, and UM-UC-3 bladder cancer cell lines. These compounds have favorable hERG and CYP inhibition profiles compared with SGI-1776, and demonstrate excellent oral bioavailability. In vivo xenograft studies using bladder cancer cell line models show that PIM kinase inhibition can reduce the tumor growth of these tumor models suggesting that PIM kinase inhibitors may be active in human urothelial carcinomas. Citation Format: Kent J. Carpenter, Rachel Brog, Christopher Moreno, Daniel J. Albertson, Jared J. Bearss, Ting Liu, Steven Warner, David J. Bearss. Small molecule iInhibitors of PIM kinases as potential treatments for urothelial carcinomas. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2174. doi:10.1158/1538-7445.AM2013-2174

Abstract With the worst five-year survival rate of any cancer, pancreatic adenocarcinomas now rank as the fourth leading cause of cancer death in adults in the United States. This necessitates increased efforts to identify new leads that will serve as therapeutic targets in our fight against this aggressive cancer. Axl is a TAM family receptor tyrosine kinase involved in multiple aspects of tumorigenesis. Increased expression of Axl is associated with increased oncogenic transformation, cell survival, proliferation, migration, angiogenesis, and cellular adhesion. The oncogenic potential of Axl was first discovered in chronic myelogenous leukemia (CML), but it has been demonstrated to play a role in the progression and metastasis of other cancer types. The known ligand for Axl is the Growth Arrest Specific Gene-6 (Gas6) protein and its binding to Axl leads to Axl autophosphorylation and activation of downstream signaling pathways including MAPK and PI3K/Akt pathways. Furthermore, target validation studies of in vivo cancer models show that inhibition of Axl expression by RNAi blocked tumor growth in those models. Taken together, this information makes Axl kinase an exciting target for small molecule drug discovery. Using HCI-2084, a small molecule Axl kinase inhibitor, we explored the effectiveness of targeting the Axl kinase in pancreatic cancer. HCI-2084 demonstrates low nanomolar (IC50 = 12 nM) activity against the Axl kinase in a biochemical assay with good selectivity for Axl when screened in a kinase panel. In 2D and 3D cell proliferation assays, HCI-2084 significantly inhibited pancreatic cancer cell growth at concentrations as low as 30 nM. In pharmacodynamic endpoint assays, HCI-2084 dramatically inhibited Akt signaling (pAKT S473) downstream of GAS6 stimulation in pancreatic cancer cell lines. Inhibition of Axl autophosphorylation by HCI-2084 was also observed in an Axl-transfected cell line system. Consistent with the known function of Axl, HCI-2084 inhibited Gas6-induced migration and invasion of pancreatic cancer cells in vitro. The proteolytic processing of the extracellular domain of the Axl receptor is a known event downstream of Axl activation and results in the release of soluble Axl (sAxl) into the cell culture media (in vitro) or into the blood stream (in vivo). We hypothesized that sAxl levels could function as a biomarker for target inhibition. Indeed, conditioned media from pancreatic cancer cell lines treated with HCI-2084 showed significant dose-dependent reductions in sAxl levels compared to the vehicle treated controls. Taken together, these results suggest Axl is a potential therapeutic target in pancreatic cancer and that HCI-2084 is an exciting agent to potentially treat this disease. HCI-2084 is currently undergoing evaluation in animal efficacy and pharmacodynamic endpoint studies. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2577. doi:10.1158/1538-7445.AM2011-2577

The receptor tyrosine kinase AXL has emerged in recent years as an potential oncology target due to its over expression in several types of cancers coupled with its ability to promote tumor growth and metastasis. In order to identify small molecule inhibitors of AXL, we built a homology model of its catalytic domain to virtually screen and identify scaffolds displaying an affinity for AXL. Further computational and structure-based design resulted in the synthesis of a series of 2,4,5-trisubstitued pyrimidines which demonstrated potent inhibition of AXL in vitro (IC(50) 19 nM) and strongly inhibited the growth of several pancreatic cell lines.

Abstract Bruton's tyrosine kinase (BTK) is a cytoplasmic nonreceptor tyrosine kinase belonging to the Tec family of kinases. Critical for its function, BTK contains a pleckstrin homology (PH) domain and Src homology SH3 and SH2 domains. It signals downstream of the B-cell receptor (BCR) and is centrally involved in B-cell development. Activation of B-cells by various ligands is accompanied by the translocation of BTK to the cell membrane where it binds phosphatidylinositol-3,4,5-trisphosphate through its PH domain. Activation of BTK results in downstream signaling through the PI3K/AKT, PLCγ, NFκB, and other signaling pathways important for B-cell development and function. Recent reports have shown the aberrant expression and function of BTK in some cancers, including B-cell malignancies. We describe here the design, synthesis, molecular modeling, and biological evaluation of a series of small molecule, inhibitors of BTK kinase. Our initial lead compounds were identified via cross-docking experiments utilizing the crystal structure of BTK kinase and screening a previously in-house explored kinase inhibitor scaffold. We subsequently carried out structure-activity relationship studies and optimized the lead structures, which have IC50 activities in the range of 1 to 10μM against BTK. A critical step in the optimization of this chemical series against BTK was to explore the possibility of adding a Michael's acceptor group to react with Cys481 in the ATP-binding pocket of BTK. Optimization efforts yielded the currently best leads, HCI-1684 and HCI-1685, which inhibit BTK with IC50 values of 12 and 45 nM, respectively. Modeling data suggest these compounds irrepressibly bind in the ATP-binding pocket of BTK. HCI-1684, HCI-1685 and other lead compounds were further evaluated in cell-based assays and were demonstrated to inhibit BTK function downstream of BCR activation. This series of BTK inhibitors were shown to decrease phospho-PLCγ1/2 levels and other downstream phosphorylation events in malignant B-cell cell lines, such as Ramos B. Compound optimization and biological evaluation of this chemical series and evaluation in animal pharmacodynamic endpoint studies will be presented. Taken together, these results suggest BTK is a potential therapeutic target in cancer and that HCI-1684 is an exciting agent to potentially treat B-cell malignancies Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2788. doi:10.1158/1538-7445.AM2011-2788

B140 DNA demethylating agents have proven to be clinically effective in prolonging survival of patients with hematological disorders such as myelodysplastic syndrome (MDS). Decitabine (5-aza-29-deoxy-cytidine) is a FDA approved, effective treatment for MDS, although it is subject to degradation by hydrolytic cleavage and to deamination by cytidine deaminase. To address this, we set out to improve the stability and thereby, increase the in vivo efficacy of decitabine by incorporating 5-aza-29-deoxy-cytidine into a guanine dinucleotide to generate a second generation decitabine agent called S110. In drug stability studies, the deamination of S110 was significantly decreased compared to decitabine; however, hydrolytic cleavage was not improved (Cancer Res 2007;67:6400-8). In cell-based systems, S110 showed equivalent activity to decitabine in real-time PCR re-expression studies looking at genes commonly methylated in cancer (p16, p15, and MLH1). Interestingly, MLH1 expression went from undetectable levels in untreated cells to substantially higher levels in S110-treated cells. In additional studies, the effect of S110 on fetal hemoglobin (HbF) levels was tested in vivo in non-human primates as a biomarker for DNA methylation. HbF levels significantly increased in baboons treated with S110 compared to pretreatment levels. We conclude that due to the improvements in drug delivery, cellular uptake, and protection from deamination, S110 is a more potent and effective DNA demethylating agent with the potential to be used in a wider variety of hematological cancers and solid tumor types.