LSD1 inhibition suppresses ASCL1 and de-represses YAP1 to drive potent activity against neuroendocrine prostate cancer

Lysine-specific demethylase 1 (LSD1 or KDM1A ) has emerged as a critical mediator of tumor progression in metastatic castration-resistant prostate cancer (mCRPC). Among mCRPC subtypes, neuroendocrine prostate cancer (NEPC) is an exceptionally aggressive variant driven by lineage plasticity, an adaptive resistance mechanism to androgen receptor axis-targeted therapies. Our study shows that LSD1 expression is elevated in NEPC and associated with unfavorable clinical outcomes. Using genetic approaches, we validated the on-target effects of LSD1 inhibition across various models. We investigated the therapeutic potential of bomedemstat, an orally bioavailable, irreversible LSD1 inhibitor with low nanomolar potency. Our findings demonstrate potent antitumor activity against CRPC models, including tumor regressions in NEPC patient-derived xenografts. Mechanistically, our study uncovers that LSD1 inhibition suppresses the neuronal transcriptional program by downregulating ASCL1 through disrupting LSD1:INSM1 interactions and de-repressing YAP1 silencing. Our data support the clinical development of LSD1 inhibitors for treating CRPC - especially the aggressive NE phenotype.

Statement of Significance

Neuroendocrine prostate cancer presents a clinical challenge due to the lack of effective treatments. Our research demonstrates that bomedemstat, a potent and selective LSD1 inhibitor, effectively combats neuroendocrine prostate cancer by downregulating the ASCL1- dependent NE transcriptional program and re-expressing YAP1.

Real-time feedback on nonverbal clinical communication. Theoretical framework and clinician acceptance of ambient visual design

INTRODUCTION

This article is part of the focus theme of Methods of Information in Medicine on "Pervasive Intelligent Technologies for Health".

BACKGROUND

Effective nonverbal communication between patients and clinicians fosters both the delivery of empathic patient-centered care and positive patient outcomes. Although nonverbal skill training is a recognized need, few efforts to enhance patient-clinician communication provide visual feedback on nonverbal aspects of the clinical encounter.

OBJECTIVES

We describe a novel approach that uses social signal processing technology (SSP) to capture nonverbal cues in real time and to display ambient visual feedback on control and affiliation--two primary, yet distinct dimensions of interpersonal nonverbal communication. To examine the design and clinician acceptance of ambient visual feedback on nonverbal communication, we 1) formulated a model of relational communication to ground SSP and 2) conducted a formative user study using mixed methods to explore the design of visual feedback.

METHODS

Based on a model of relational communication, we reviewed interpersonal communication research to map nonverbal cues to signals of affiliation and control evidenced in patient-clinician interaction. Corresponding with our formulation of this theoretical framework, we designed ambient real-time visualizations that reflect variations of affiliation and control. To explore clinicians' acceptance of this visual feedback, we conducted a lab study using the Wizard-of-Oz technique to simulate system use with 16 healthcare professionals. We followed up with seven of those participants through interviews to iterate on the design with a revised visualization that addressed emergent design considerations.

RESULTS

Ambient visual feedback on non- verbal communication provides a theoretically grounded and acceptable way to provide clinicians with awareness of their nonverbal communication style. We provide implications for the design of such visual feedback that encourages empathic patient-centered communication and include considerations of metaphor, color, size, position, and timing of feedback.

CONCLUSIONS

Ambient visual feedback from SSP holds promise as an acceptable means for facilitating empathic patient-centered nonverbal communication.

The effect of smoking on bone healing: A systematic review

Objectives

To review the systemic impact of smoking on bone healing as evidenced within the orthopaedic literature.

Methods

A protocol was established and studies were sourced from five electronic databases. Screening, data abstraction and quality assessment was conducted by two review authors. Prospective and retrospective clinical studies were included. The primary outcome measures were based on clinical and/or radiological indicators of bone healing. This review specifically focused on non-spinal orthopaedic studies.

Results

Nine tibia studies and eight other orthopaedic studies were considered for systematic review. Of these 17 studies, 13 concluded that smoking negatively influenced bone healing.

Conclusions

Smoking has a negative effect on bone healing, in terms of delayed union, nonunion and more complications.

Abstract 5556: Discovery of RKI-18, a small molecule that inhibits Rho kinases 1 and 2, migration and invasion of human tumors

Signal transduction pathways that are mediated by ROCK1 and ROCK2 trigger cell migration, invasion and metastasis. This prompted us to design and synthesize novel Rho-kinase inhibitors (RKIs). Here, we show that one of our most potent RKIs, RKI-18 (IC50 397 nM (ROCK1) and 349 nM (ROCK2)) but not its inactive closely related analogue RKI-11 suppresses potently the phosphorylation of the ROCK substrate MLC2 in intact human cancer cells. Furthermore, RKI-18 is highly selective at inhibiting P-MLC2 over P-Akt, P-S6 and P-Erk ½ levels. RKI-18 suppresses ROCK-mediated actin fiber formation following stimulation with LPA as well as PAK-mediated lamelipodia and filopodia formation following bradykinin or PDGF stimulation. Furthermore, RKI-18 but not RKI-11 inhibits migration, invasion and anchorage-independent growth of human breast cancer cells. The fact that RKI-18, the active ROCK inhibitor, but not RKI-11, its inactive analogue, is effective at suppressing malignant transformation suggests that preventing migration, invasion and anchorage-independent growth with RKI-18 is likely due to inhibition of ROCK. Further advanced preclinical studies are required to determine the potential of RKI-18 as an anti-metastatic agent.

Citation Format: Ronil A. Patel, Yan Lui, Binglin Wang, Ronshi Li, Said M. Sebti. Discovery of RKI-18, a small molecule that inhibits Rho kinases 1 and 2, migration and invasion of human tumors. [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 5556. doi:10.1158/1538-7445.AM2013-5556

Identification of novel ROCK inhibitors with anti-migratory and anti-invasive activities

ROCK1 and ROCK2 mediate important processes such as cell migration, invasion and metastasis; making them good targets for the development of antitumor agents. Recently, using a fragment-based approach and X-ray crystallography, we reported on the design and synthesis of novel Rho-kinase inhibitors (RKIs). Here, we selected a pair of RKIs, the closely-related structural analogues RKI-18 (potent; IC₅₀ values of 397 nM (ROCK1) and 349 nM (ROCK2)) and RKI-11 (weak/inactive; IC₅₀ values of 38 µM (ROCK1) and 45 µM (ROCK2), as chemical probes and determined their effects on cytoskeleton organization, signaling, apoptosis, anchorage-dependent and –independent growth, migration and invasion. RKI-18 but not RKI-11 suppresses potently the phosphorylation of the ROCK substrate MLC2 in intact human breast, lung, colon and prostate cancer cells. Furthermore, RKI-18 is highly selective at decreasing the levels of P-MLC2 over those of P-Akt, P-S6 and P-Erk ½. RKI-18 suppresses ROCK-mediated actin fiber formation following stimulation with LPA as well as PAK-mediated lamelipodia and filopodia formation following bradykinin or PDGF stimulation. Furthermore, RKI-18 but not RKI-11 inhibits migration, invasion and anchorage-independent growth of human breast cancer cells. The fact that the active ROCK inhibitor RKI-18 but not the inactive closely related structural analogue RKI-11 is effective at suppressing malignant transformation suggests that inhibition of ROCK with RKI-18 results in preventing migration, invasion and anchorage-independent growth. The potential of this class of RKIs as anti tumor agents warrants further advanced preclinical studies.

RKI-1447 is a potent inhibitor of the Rho-associated ROCK kinases with anti-invasive and antitumor activities in breast cancer

The Rho-associated kinases ROCK1 and ROCK2 are critical for cancer cell migration and invasion, suggesting they may be useful therapeutic targets. In this study, we describe the discovery and development of RKI-1447, a potent small molecule inhibitor of ROCK1 and ROCK2. Crystal structures of the RKI-1447/ROCK1 complex revealed that RKI-1447 is a Type I kinase inhibitor that binds the ATP binding site through interactions with the hinge region and the DFG motif. RKI-1447 suppressed phosphorylation of the ROCK substrates MLC-2 and MYPT-1 in human cancer cells, but had no effect on the phosphorylation levels of the AKT, MEK, and S6 kinase at concentrations as high as 10 μmol/L. RKI-1447 was also highly selective at inhibiting ROCK-mediated cytoskeleton re-organization (actin stress fiber formation) following LPA stimulation, but does not affect PAK-meditated lamellipodia and filopodia formation following PDGF and Bradykinin stimulation, respectively. RKI-1447 inhibited migration, invasion and anchorage-independent tumor growth of breast cancer cells. In contrast, RKI-1313, a much weaker analog in vitro, had little effect on the phosphorylation levels of ROCK substrates, migration, invasion or anchorage-independent growth. Finally, RKI-1447 was highly effective at inhibiting the outgrowth of mammary tumors in a transgenic mouse model. In summary, our findings establish RKI-1447 as a potent and selective ROCK inhibitor with significant anti-invasive and antitumor activities and offer a preclinical proof-of-concept that justify further examination of RKI-1447 suitability as a potential clinical candidate.

Abstract 2942: RKI-1447, a potent ROCK inhibitor with anti-tumor and anti-invasive activities in breast cancer

Rho-associated kinases 1 and 2 (ROCKs) are intimately involved in metastasis and this prompted the development of ROCK inhibitors (RKIs) as anti-metastatic agents. Here, we describe the development of RKI-1447 which inhibits ROCK 1 and 2 potently in vitro (IC50s; 14 and 6 nM, respectively) and suppresses the phosphorylation of ROCK substrates MLC2 and MYPT1 in human breast cancer cells (IC50; 100 nM). The crystal structure of the RKI-1447-ROCK1 complex reveals that RKI-1447 binds the hinge region in the ATP binding site. RKI-1447 is highly selective and does not affect the phosphorylation levels of Akt, Erk, Mek and S6. RKI-1447 is also highly selective at inhibiting ROCK-mediated cytoskeleton re-organization (actin stress fiber formation) following LPA stimulation, but does not affect PKA-meditated lamelipodia and filopodia formation following PDGF and bradykinin stimulation, respectively. RKI-1447 inhibits migration, invasion and anchorage-independent tumor growth of breast cancer cells. A structurally-related analog RKI-1313 that is inactive against ROCKs in vitro (IC50 > 10 µM) has little effects on migration, invasion and anchorage-independent growth. Finally, RKI-1447 is highly effective at inhibiting the growth of ErbB2-driven breast tumors in a transgenic animal model.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2942. doi:1538-7445.AM2012-2942

Fragment-based and structure-guided discovery and optimization of Rho kinase inhibitors

Using high concentration biochemical assays and fragment-based screening assisted by structure-guided design, we discovered a novel class of Rho-kinase inhibitors. Compound 18 was equipotent for ROCK1 (IC(50) = 650 nM) and ROCK2 (IC(50) = 670 nM), whereas compound 24 was more selective for ROCK2 (IC(50) = 100 nM) over ROCK1 (IC(50) = 1690 nM). The crystal structure of the compound 18-ROCK1 complex revealed that 18 is a type 1 inhibitor that binds the hinge region in the ATP binding site. Compounds 18 and 24 inhibited potently the phosphorylation of the ROCK substrate MLC2 in intact human breast cancer cells.

Abstract A130: Fragment-based discovery and optimization of Rho kinase inhibitors

Using high concentration biochemical assays and fragment-based screening, we designed and optimized a novel class of Rho-kinase inhibitors. Ligand Efficiency (LE) was employed to assess the binding potential of the fragments and to guide the optimization process. In addition, molecular modeling was used to aide the design of potent inhibitors. A series of fragments as hinge binders were designed and synthesized, and screened using high concentration biochemical assays. Both the spacer length and isomeric tail molecules played key roles in both activity and selectivity. Structure activity relationship studies led to optimization of fragments that yielded potent and selective ROCK 1 and ROCK 2 inhibitors. For instance, compound 24 was highly potent and selective for ROCK 2 (IC50 = 100 nM) over ROCK 1 (IC50 = 1690 nM) whereas compound 18 was potent and selective for ROCK 1 (IC50 = 460 nM) over ROCK 2 (IC50 = 700nM). Compound 24 but not its inactive stereoisomer 23, and compound 18 but not its inactive analog 11 inhibited the phosphorylation of Rho Kinase substrates in intact human cancer cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A130.

Hypersensitivity pneumonitis: patterns on high-resolution CT

Hypersensitivity pneumonitis, also known as extrinsic allergic alveolitis, is caused by inhalation of specific environmental organic antigens. This disease may have typical high-resolution CT findings that, in the appropriate clinical setting, can be sufficiently characteristic to allow a confident diagnosis without the need for a lung biopsy. In this pictorial essay, the high-resolution CT patterns of hypersensitivity pneumonitis are illustrated. The authors emphasize the correlation among the radiologic presentation, functional abnormalities, and pathologic findings.

Helical CT for the evaluation of suspected acute pulmonary embolism: diagnostic pitfalls

Helical CT is being increasingly utilized for the evaluation of suspected pulmonary embolism (PE). Proper scan interpretation depends on the awareness of several diagnostic pitfalls that may simulate PE, including normal bronchovascular structures such as pulmonary veins, bronchi, and lymph nodes, technical considerations such as improper bolus timing and streak artifacts, and patient-related factors such as motion artifacts, pulmonary arterial catheters, and vascular shunts. An understanding of these pitfalls facilitates accurate diagnosis.

Preliminary experience with use of a selective 5HT3 receptor antagonist (ondansetron) to prevent high dose chemotherapy induced emesis

Ondansetron was used as an antiemetic along with dexamethasone during 16 cycles of highly or moderately ematogenic chemotherapy. There was major control in two cycles and complete control in the remaining 14. Side effects were minor and did not require discontinuation of the drug. This combination, therefore, appears to be safe and effective in preventing chemotherapy induced emesis.

Insulin stimulates phosphatidylinositol 3-kinase activity in rat neuronal primary cultures

We investigated the effect of insulin on phosphatidylinositol (PtdIns) 3-kinase (PtdIns 3-kinase) activity in neuronal cultures to determine if this enzyme is involved with the neurotrophic actions of insulin. Insulin caused a concentration-dependent increase in PtdIns 3-kinase activity in anti-phosphotyrosine immunoprecipitates. The kinase activity was able to phosphorylate PtdIns, PtdIns 4-phosphate, and PtdIns 4,5-bisphosphate. In intact neurons, a 10-min 1 mM insulin treatment in the presence of [32P]orthophosphate increased the levels of both 3-[32P]PtdIns phosphate and 3,4-[32P]PtdIns bisphosphate by 55 and 193%, respectively. This increase was associated with an increase in neurite outgrowth mediated by insulin. Our results indicate that insulin treatment of neuronal cells in primary culture increases PtdIns 3-kinase activity and the formation of the unique D-3-phosphorylated phosphoinositides, suggesting that growth factor-mediated neuronal growth may include the formation of novel phosphoinositide 3-phosphate phospholipids.

Epstein-Barr virus infectivity of Raji and Molt 4 cells: differences in cellular membrane lipids and apparent microviscosity

Infection of lymphocytes by the Epstein-Barr virus (EBV) is initiated by attachment of the major virus glycoprotein gp350/220 to a cell surface glycoprotein, known as CR2 (CD21). In a productive infection the virus envelope fuses with host cell membranes either at the cell surface or within endocytic vesicles. To investigate the relevance of host cell membrane properties in the fusion process, we used the lymphoblastoid cell lines Raji and Molt 4. Both cell lines express CR2 and bind EBV; however, only the Raji cell supports virus-cell fusion. Lipid analysis of the two cell lines indicated that Raji cells had a significantly lower cholesterol to phospholipid molar ratio due to a greater membrane content of phospholipid relative to protein. Determination of cell membrane fluid dynamics by fluorescence polarization indicated that the apparent membrane microviscosity of Molt 4 cells was significantly greater than that of Raji. Increasing Raji cell membrane apparent microviscosity to values similar to those of Molt 4 cells by incubation with cholesteryl-hemisuccinate caused a reduction in EBV fusion with Raji cells. However, experiments designed to allow EBV infection of Molt 4 cells whose plasma membranes had been fluidized were unsuccessful. These studies suggest that the lipid composition and other as yet unidentified factors are involved in entry of EBV into cells.

Bayesian forecasting of serum lithium concentrations. Comparison with traditional methods

Twelve pharmacokinetic methods of estimating lithium maintenance dosage requirements were compared in 21 patients with bipolar illness. Methods which were compared included the single- and multiple-point methods of Perry, 4 non-linear regression and 6 Bayesian methods. The REVOL algorithm was employed for converging on to estimates of clearance and apparent volume of distribution for the non-linear regression and Bayesian methods. Data analysis was based on an evaluation of prediction error as a measure of bias, and absolute prediction error as a measure of precision. In a direct comparison, there were no statistically significant differences in bias or precision between any of the methods.

Comparison of pharmacokinetic procedures for dosing lithium based on analysis of prediction error

Five pharmacokinetic methods for estimating maintenance dosage requirements of lithium carbonate were compared retrospectively in 20 inpatients with acute bipolar illness. Specific pharmacokinetic methods tested included the method of Cooper, the multiple-point method of Perry, the single-point method of Perry, the method of Zetin, and the method of Pepin. Data analysis was based on evaluation of prediction error or the difference between the predicted steady-state lithium concentration and the measured steady-state lithium concentration at equivalent daily doses. Each dosing method was assessed in regard to accuracy and bias of predicted steady-state serum lithium concentrations. Bias was assessed by comparison of the median value of the prediction error with zero. The dosing recommendation based on the Cooper nomogram resulted in a significant positive bias (p less than or equal to 0.05). Intermethod accuracy was assessed by comparison of the absolute prediction errors of each dosing method. Significant differences in accuracy were observed between the method of Pepin when compared with the single-point method of Perry (p less than or equal to 0.05, k-sample sign test). All other comparisons were nonsignificant.

Transdermal delivery of isoproterenol HCl: an investigation of stability, solubility, partition coefficient, and vehicle effects

Effects of solubility, partition coefficient, and selected adjuvants (propylene glycol and Azone) on percutaneous penetration of isoproterenol HCl have been investigated using human cadaver skin. Isoproterenol was found to be stable (less than 1% decomposition) for 24 hr at 22 +/- 0.5 degrees C in the pH range 1 to 7 in the following solvents: water, normal saline, propylene glycol and a series of propylene glycol-water mixtures (10, 20, 40, and 60%; v/v); however, decomposition was significant beyond pH 8. In normal saline, the rate of decomposition increased significantly with an increase in temperature to 37 degrees C. The solubility of isoproterenol HCl decreased and its skin/vehicle partition coefficient increased with increasing proportions of propylene glycol in the vehicle, while the product of the solubility and partition coefficient appeared to plateau at 20% propylene glycol in water. Optimal penetration enhancing effects of Azone were seen when incorporated at a concentration of 1% (v/v) in the 20% (v/v) propylene glycol-water blend and, more significantly, when skin was pretreated with pure Azone for 60 min prior to application of the drug formulation.