Activation Of Cell Survival Pathways Research Articles

Impact of genomic background and developmental state on signaling pathways and response to therapy in glioblastoma patient-derived cells.

Glioblastoma (GBM) tumors represents diverse genomic epigenomic, and transcriptional landscapes, with significant intratumoral heterogeneity that challenges standard of care treatments involving radiation (RT) and the DNA-alkylating agent temozolomide (TMZ). In this study, we employed targeted proteomics to assess the response of a genomically-diverse panel of GBM patient-derived cancer stem cells (CSCs) to astrocytic differentiation, growth factor withdrawal and traditional high fetal bovine serum culture. Our findings revealed a complex crosstalk and co-activation of key oncogenic signaling in CSCs and diverse patterns of response to these external stimuli. Using RNA sequencing and DNA methylation, we observed common adaptations in response to astrocytic differentiation of CSCs across genomically distinct models, including BMP-Smad pathway activation, reduced cholesterol biosynthesis, and upregulation of extracellular matrix components. Notably, we observed that these differentiated CSC progenies retained a subset of stemness genes and the activation of cell survival pathways. We also examined the impact of differentiation state and genomic background on GBM cell sensitivity and transcriptional response to TMZ and RT. Differentiation of CSCs increased resistance to TMZ but not to RT. While transcriptional responses to these treatments were predominantly regulated by p53 in wild-type p53 GBM cells, its transcriptional activity was modulated by the differentiation status and treatment modality. Both mutant and wild-type p53 models exhibited significant activation of a DNA-damage associated interferon response in CSCs and differentiated cells, suggesting this pathway may play a wider role in GBM response to TMZ and RT. Our integrative analysis of the impact of GBM cell developmental states, in the context of genomic and molecular diversity of patient-derived models, provides valuable insights for pre-clinical studies aimed at optimizing treatment strategies.

Korean Red Ginseng suppresses emphysematous lesions induced by cigarette smoke condensate through inhibition of macrophage-driven apoptosis pathways

BackgroundCigarette smoke is generally accepted as a major contributor to chronic obstructive pulmonary disease (COPD), which is characterized by emphysematous lesions. In this study, we investigated the protective effects of Korean Red Ginseng (KRG) against cigarette smoke condensate (CSC)-induced emphysema. MethodsMice were instilled with 50 mg/kg of CSC intranasally once a week for 4 weeks, KRG was administered to the mice once daily for 4 weeks at doses of 100 or 300 mg/kg, and dexamethasone (DEX, positive control) was administered to the mice once daily for 2 weeks at 3 mg/kg. ResultsKRG markedly decreased the macrophage population in bronchoalveolar lavage fluid and reduced emphysematous lesions in the lung tissues. KRG suppressed CSC-induced apoptosis as revealed by terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling staining and Caspase 3 immunohistochemistry. Additionally, KRG effectively inhibited CSC-mediated activation of Bcl-2-associated X protein/Caspase 3 signaling, followed by the induction of cell survival signaling, including vascular endothelial growth factor/phosphoinositide 3-kinase/protein kinase B in vivo and in vitro. The DEX group also showed similar improved results in vivo and in vitro. ConclusionTaken together, KRG effectively inhibits macrophage-mediated emphysema induced by CSC exposure, possibly via the suppression of pro-apoptotic signaling, which results in cell survival pathway activation. These findings suggest that KRG has therapeutic potential for the prevention of emphysema in COPD patients.

Age-Associated Resilience Against Ischemic Injury in Mice Exposed to Transient Middle Cerebral Artery Occlusion.

Ischemic stroke is the leading cause of death and disability. Although stroke mainly affects aged individuals, animal research is mostly one on young rodents. Here, we examined the development of ischemic injury in young (9-12-week-old) and adult (72-week-old) C57BL/6 and BALB/c mice exposed to 30 min of intraluminal middle cerebral artery occlusion (MCAo). Post-ischemic reperfusion did not differ between young and adult mice. Ischemic injury assessed by infarct area and blood-brain barrier (BBB) integrity assessed by IgG extravasation analysis was smaller in adult compared with young mice. Microvascular viability and neuronal survival assessed by CD31 and NeuN immunohistochemistry were higher in adult than young mice. Tissue protection was associated with stronger activation of cell survival pathways in adult than young mice. Microglial/macrophage accumulation and activation assessed by F4/80 immunohistochemistry were more restricted in adult than young mice, and pro- and anti-inflammatory cytokine and chemokine responses were reduced by aging. By means of liquid chromatography-mass spectrometry, we identified a hitherto unknown proteome profile comprising the upregulation of glycogen degradation-related pathways and the downregulation of mitochondrial dysfunction-related pathways, which distinguished post-ischemic responses of the aged compared with the young brain. Our study suggests that aging increases the brain's resilience against ischemic injury.

Abstract ED3-3A: Mechanisms of resistance

Abstract Antibody Drug Conjugates (ADCs) are emerging as promising therapeutics for all subtypes of breast cancer. ADCs are composed of a monoclonal antibody directed against a tumor-expressed antibody, conjugated via a variety of linker chemistries to a cytotoxic or other tumor-active payload. Tumor-selective drug delivery via ADCs has the potential to substantially improve the therapeutic window and efficacy for a variety of therapeutic agents. Indeed, recent clinical data have demonstrated significant improvements in overall survival with the use of single-agent ADCs across the spectrum of advanced breast cancer. However, both de novo and acquired resistance to ADCs is common, and may involve a diverse array of potential mechanisms that reflect the complexity of ADC action. These include alteration or downregulation of the ADC target, deregulation of intracellular trafficking or endolysosomal processing of the internalized ADC, and a variety of payload-specific mechanisms of resistance such as induction of drug efflux or activation of cell survival pathways. Which mechanism(s) dominates in a given setting may depend on both ADC-specific and tumor-specific factors. For example, linker design is likely to have a major influence on potential ADC resistance: ADCs with a non-cleavable linker (e.g. trastuzumab emtansine) are dependent upon fusion with acidified lysosomes for degradation and payload release, and attenuated acidification has been demonstrated pre-clinically as a resistance mechanism. In contrast, ADCs with a cleavable peptide linker (e.g. trastuzumab deruxtecan) may not require lysosomal processing for payload release. Furthermore, highly genetically unstable tumors may simultaneously generate multiple types of resistance mechanisms. We recently demonstrated the emergence of distinct acquired resistance mutations to sacituzumab govitecan, involving the ADC antibody target (TROP2) and the payload target (topoisomerase 1), within different metastatic lesions of an individual patient. General strategies to overcome ADC resistance include the sequential use of multiple ADCs, and/or the up-front use of select combination therapies incorporating ADCs. Clearly, the success of these approaches will require a more thorough evaluation and understanding of resistance mechanisms as they occur in patients. Fortunately, the relative success of ADCs for breast cancer treatment to date is spurring the identification of new targets, approaches for linker design, and a wide diversity of payloads that will be instrumental for efforts to overcome resistance. Citation Format: Leif Ellisen. Mechanisms of resistance [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr ED3-3A.

Subtype of Neuroblastoma Cells with High KIT Expression Are Dependent on KIT and Its Knockdown Induces Compensatory Activation of Pro-Survival Signaling.

Neuroblastoma (NB) is a pediatric cancer with high clinical and molecular heterogeneity, and patients with high-risk tumors have limited treatment options. Receptor tyrosine kinase KIT has been identified as a potential marker of high-risk NB and a promising target for NB treatment. We investigated 19,145 tumor RNA expression and molecular pathway activation profiles for 20 cancer types and detected relatively high levels of KIT expression in NB. Increased KIT expression was associated with activation of cell survival pathways, downregulated apoptosis induction, and cell cycle checkpoint control pathways. KIT knockdown with shRNA encoded by lentiviral vectors in SH-SY5Y cells led to reduced cell proliferation and apoptosis induction up to 50%. Our data suggest that apoptosis induction was caused by mitotic catastrophe, and there was a 2-fold decrease in percentage of G2-M cell cycle phase after KIT knockdown. We found that KIT knockdown in NB cells leads to strong upregulation of other pro-survival growth factor signaling cascades such as EPO, NGF, IL-6, and IGF-1 pathways. NGF, IGF-1 and EPO were able to increase cell proliferation in KIT-depleted cells in an ERK1/2-dependent manner. Overall, we show that KIT is a promising therapeutic target in NB, although such therapy efficiency could be impeded by growth factor signaling activation.

Neuroprotective Effects of Cholinesterase Inhibitors: Current Scenario in Therapies for Alzheimer's Disease and Future Perspectives.

Alzheimer’s disease (AD) is a slowly progressive neurodegenerative disease conceptualized as a continuous process, ranging from mild cognitive impairment (MCI), to the mild, moderate, and severe clinical stages of AD dementia. AD is considered a complex multifactorial disease. Currently, the use of cholinesterase inhibitors (ChEI), such as tacrine, donepezil, rivastigmine, and galantamine, has been the main treatment for AD patients. Interestingly, there is evidence that ChEI also promotes neuroprotective effects, bringing some benefits to AD patients. The mechanisms by which the ChEI act have been investigated in AD. ChEI can modulate the PI3K/AKT pathway, which is an important signaling cascade that is capable of causing a significant functional impact on neurons by activating cell survival pathways to promote neuroprotective effects. However, there is still a huge challenge in the field of neuroprotection, but in the context of unravelling the details of the PI3K/AKT pathway, a new scenario has emerged for the development of more efficient drugs that act on multiple protein targets. Thus, the mechanisms by which ChEI can promote neuroprotective effects and prospects for the development of new drug candidates for the treatment of AD are discussed in this review.

Caffeic acid phenethyl ester targets ubiquitin-specific protease 8 and synergizes with cisplatin in endometrioid ovarian carcinoma cells

Deubiquitinases (DUBs) mediate the removal of ubiquitin from diverse proteins that participate in the regulation of cell survival, DNA damage repair, apoptosis and drug resistance. Previous studies have shown an association between activation of cell survival pathways and platinum-drug resistance in ovarian carcinoma cell lines. Among the strategies available to inhibit DUBs, curcumin derivatives appear promising, thus we hypothesized their use to enhance the efficacy of cisplatin in ovarian carcinoma preclinical models. The caffeic acid phenethyl ester (CAPE), inhibited ubiquitin-specific protease 8 (USP8), but not proteasomal DUBs in cell-free assays. When CAPE was combined with cisplatin in nine cell lines representative of various histotypes a synergistic effect was observed in TOV112D cells and in the cisplatin-resistant IGROV-1/Pt1 variant, both of endometrioid type and carrying mutant TP53. In the latter cells, persistent G1 accumulation upon combined treatment associated with p27kip1 protein levels was observed. The synergy was not dependent on apoptosis induction, and appeared to occur in cells with higher USP8 levels. In vivo antitumor activity studies supported the advantage of the combination of CAPE and cisplatin in the subcutaneous model of cisplatin-resistant IGROV-1/Pt1 ovarian carcinoma as well as CAPE activity on intraperitoneal disease. This study reveals the therapeutic potential of CAPE in cisplatin-resistant ovarian tumors as well as in tumors expressing USP8.

LSD1 and Aberrant DNA Methylation Mediate Persistence of Enteroendocrine Progenitors That Support BRAF-Mutant Colorectal Cancer.

Despite the connection of secretory cells, including goblet and enteroendocrine (EEC) cells, to distinct mucus-containing colorectal cancer histologic subtypes, their role in colorectal cancer progression has been underexplored. Here, our analysis of The Cancer Genome Atlas (TCGA) and single-cell RNA-sequencing data demonstrates that EEC progenitor cells are enriched in BRAF-mutant colorectal cancer patient tumors, cell lines, and patient-derived organoids. In BRAF-mutant colorectal cancer, EEC progenitors were blocked from differentiating further by DNA methylation and silencing of NEUROD1, a key gene required for differentiation of intermediate EECs. Mechanistically, secretory cells and the factors they secrete, such as trefoil factor 3, promoted colony formation and activation of cell survival pathways in the entire cell population. Lysine-specific demethylase 1 (LSD1) was identified as a critical regulator of secretory cell specification in vitro and in a colon orthotopic xenograft model, where LSD1 loss blocks formation of EEC progenitors and reduces tumor growth and metastasis. These findings reveal an important role for EEC progenitors in supporting colorectal cancer. SIGNIFICANCE: This study establishes enteroendocrine progenitors as a targetable population that promotes BRAF-mutant colorectal cancer and can be blocked by LSD1 inhibition to suppress tumor growth.

Hepatic transcriptome signature correlated with HOMA-IR explains early nonalcoholic fatty liver disease pathogenesis

Introduction and objectivesNon-alcoholic fatty liver disease (NAFLD) is multistage with heterogeneous outcomes. We studied the influence of insulin resistance (IR) on the hepatic transcriptome of early NAFLD stages, to understand disease development. Materials and methodsIn this cross-sectional study, possible clinicopathological risk factors were compared between mild-NAFL (N = 72) and non-alcoholic steatohepatitis (NASH; N = 51) patients. Liver tissue-transcriptome difference was studied between a subset of 25 mild-NAFL and 20 NASH biopsies and validated on another subset of 12 mild-NAFL and 13 NASH biopsies, using RT-PCR. The relationship between IR driven gene expression changes with fibrosis in NASH was investigated. ResultsSignificantly higher weight (p = 0.005) and elevated levels of HbA1c (p = 0.009), FBG (p = 0.03) and HOMA-IR (p = 0.009) were found in NASH patients. Five differentially expressed genes (DEGs, fold change > 1.5) were identified in NASH-FABP4, FABP5L2, CD24, PRAP1, and SPP1. The DEGs were positively associated with disease severity and HOMA-IR, and were found to be efficient classifiers of mild-NAFL and NASH. Additional 1218 genes identified related to IR (IrCGs), which can classify NASH-with-fibrosis patients separately from mild-NAFL and NASH patients. IrCGs can promote intra-hepatic fat accumulation, dysregulation of the lipid metabolism, lipotoxicity, and activation of cell survival pathways including activation of cell proliferation and differentiation pathways. ConclusionsHepatic expression of genes associated with insulin resistance may drive NAFLD development and progression.

Grape Powder Supplementation Attenuates Prostate Neoplasia Associated with Pten Haploinsufficiency in Mice Fed High-Fat Diet.

Previous studies have identified potent anticancer activities of polyphenols in preventing prostate cancer. The aim of the current study is to evaluate the chemopreventive potential of grape powder (GP) supplemented diets in genetically predisposed and obesity-provoked prostate cancer. Prostate-specific Pten heterozygous (Pten+/f ) transgenic mice are fed low- and high-fat diet (LFD and HFD, respectively) supplemented with 10% GP for 33 weeks, ad libitum. Prostate tissues are characterized using immunohistochemistry and western blots, and sera are analyzed by ELISA and qRT-PCR. Pten+/f mice fed LFD and HFD supplemented with 10% GP show favorable histopathology, significant reduction of the proliferative rate of prostate epithelial cells (Ki67), and rescue of PTEN expression. The most potent protective effect of GP supplementation is detected against HFD-induced increase in inflammation (IL-1β; TGF-β1), activation of cell survival pathways (Akt, AR), and angiogenesis (CD31) in Pten+/f mice. Moreover, GP supplementation reduces circulating levels of oncogenic microRNAs (miR-34a; miR-22) in Pten+/f mice. There are no significant changes in body weight and food intake in GP supplemented diet groups. GP diet supplementation can be a beneficial chemopreventive strategy for obesity-related inflammation and prostate cancer progression. Monitoring serum miRNAs can facilitate the non-invasive evaluation of chemoprevention efficacy.

Sodium-Dependent Glucose Transporter 1 (SGLT1) Stabled by HER2 Promotes Breast Cancer Cell Proliferation by Activation of the PI3K/Akt/mTOR Signaling Pathway in HER2+ Breast Cancer.

Aerobic glycolysis is a hallmark of tumor cells. SGLT1 plays a vital role in glucose metabolism. However, whether SGLT1 could promote cell growth and proliferation in breast cancer remains unclear. Here, we investigated the expression of SGLT1 in breast cancer and examined its role in malignant behavior and prognosis. Further, we examined the SGLT1 expression in breast cancer tissues and its relationship with clinicopathologic characteristics. We clarified that SGLT1 was overexpressed in HER2+ breast cancer cell lines and was affected by HER2 status. We further found that SGLT1 affected breast cancer cell proliferation and patient survival by mediating cell survival pathway activation. SGLT1 was overexpressed in HER2+ breast cancers and associated with lymph node metastasis and HER2+ status. Inhibition of HER2 decreased SGLT1 expression, and the extracellular acidification rate was also reduced in the UACC812 and SKBR3 cell lines. These changes could be reversed by proteasome inhibitor treatment. Knockdown of SGLT1 blocked PI3K/Akt/mTOR signaling, thereby inhibiting cell proliferation. Further, we demonstrated that high SGLT1 was significantly correlated with shorter survival in all breast cancer patients and specifically in HER2+ breast cancer patients. Therefore, we conclude that SGLT1 is overexpressed in HER2+ breast cancer, thereby promoting cell proliferation and shortening survival by activating PI3K/Akt/mTOR signaling. This study submits that SGLT1 is promising not only as a novel biomarker of HER2+ breast cancer subtype but also as a potential drug target.

Canagliflozin reduces cisplatin uptake and activates Akt to protect against cisplatin-induced nephrotoxicity.

Cisplatin is a widely used chemotherapy drug with notorious nephrotoxicity. Na+-glucose cotransporter 2 inhibitors are a class of novel antidiabetic agents that may have other effects in the kidneys besides blood glucose control. In the present study, we demonstrated that canagliflozin significantly attenuates cisplatin-induced nephropathy in C57BL/6 mice and suppresses cisplatin induced renal proximal tubular cell apoptosis in vitro. The protective effect of canagliflozin was associated with inhibition of p53, p38 and JNK activation. Mechanistically, canagliflozin partially reduced cisplatin uptake by kidney tissues in mice and renal tubular cells in culture. In addition, canagliflozin enhanced the activation of Akt and inhibited the mitochondrial pathway of apoptosis during cisplatin treatment. The protective effect of canagliflozin was diminished by the phosphatidylinositol 3-kinase/Akt inhibitor LY294002. Notably, canagliflozin did not affect the chemotherapeutic efficacy of cisplatin in A549 and HCT116 cancer cell lines. These results suggest a new application of canagliflozin for renoprotection in cisplatin chemotherapy. Canagliflozin may protect kidneys by reducing cisplatin uptake and activating cell survival pathways.

Blocking pro-inflammatory platelet-activating factor receptors and activating cell survival pathways: A novel therapeutic strategy in experimental ischemic stroke.

OBJECTIVE:Acute ischemic stroke triggers complex neurovascular, neuroinflammatory, and synaptic alterations. This study explores whether blocking pro-inflammatory platelet-activating factor receptor (PAF-R) plus selected docosanoids after middle cerebral artery occlusion (MCAo) would lead to neurological recovery. The following small molecules were investigated: (a) LAU-0901, a PAF-R antagonist that blocks pro-inflammatory signaling; and (b) derivatives of docosahexaenoic acid (DHA), neuroprotectin D1 (NPD1), and aspirin-triggered NPD1 (AT-NPD1), which activates cell survival pathways and are exert potent anti-inflammatory activity in the brain.MATERIALS AND METHODS:Sprague-Dawley rats received 2 h MCAo and LAU-0901 (30 or 60 mg/kg, 2 h after stroke), NPD1, and AT-NPD1 (333 μg/kg), DHA (5 mg/kg), and their combination were administered intravenous at 3 h after stroke. Behavior testing and ex vivo magnetic resonance imaging were conducted on day 3 or 14 to assess lesion characteristics and lipidomic analysis on day 1. Series 1 (LAU-0901 + NPD1, 14d), Series 2 (LAU-0901 + AT-NPD1, 3d), and Series 3 (LAU-0901 + DHA, 1d).RESULTS:All combinatory groups improved behavior compared to NPD1, AT-NPD1, or DHA treatments alone. Total lesion volumes were reduced with LAU-0901 + NPD1 by 62% and LAU-0901 + AT-NPD1 by 90% treatments versus vehicle groups. LAU-0901 and LAU-0901 + DHA increased the production of vasoactive lipid mediators (prostaglandins: PGE2, PGF2-α, 6-keto-PGF1-α, and PGD2) as well an inflammatory regulating mediator hydroxyoctadecadienoic acid. In contrast, LAU-0901 and LAU-0901 + DHA decreased the production of 12-hydroxyeicosatetraenoic acid, a pro-inflammatory mediator.CONCLUSION:Combination therapy with LAU-0901 and selected docosanoids is more effective than the single therapy, affording synergistic neuroprotection, with restored pro-homeostatic lipid mediators and improved neurological recovery. Altogether, our findings support the combinatory therapy as the basis for future therapeutics for ischemic stroke.

Peptidylarginine Deiminase 2 Knockout Improves Survival in hemorrhagic shock.

The peptidylarginine deiminase (PAD) family converts arginine into citrulline through protein citrullination. PAD2 and PAD4 inhibitors can improve survival in hemorrhagic shock (HS). However, the impact of isoform-specific PAD inhibition in improving survival has not been studied. In this study, we utilize selective Pad2 knockout mice to elucidate loss of function of PAD2 leads to pro-survival effect in HS. HS: Pad2 and wild-type (WT) mice (n = 5/group) were subjected to lethal HS (55% volume hemorrhage). Survival was monitored over 7 days. Myocardial infarction (MI): Pad2 and WT mice (n = 9/group) were subjected to MI by permanent LAD ligation to examine the effect of ischemia on the heart. After 24 h cardiac function and infarct size were measured. HS: Pad2 mice demonstrated 100% survival compared with 0% for WT mice (P = 0.002). In a sub-lethal HS model, cardiac β-catenin levels were higher in Pad2 compared with WT after 24 h. MI: WT mice demonstrated larger MI (75%) compared with Pad2 (60%) (P < 0.05). Pad2 had significantly higher ejection fraction and fractional shortening compared with WT (P < 0.05). Pad2 improves survival in lethal HS. Possible mechanisms by which loss of PAD2 function improves survival include the activation of cell survival pathways, improved tolerance of cardiac ischemia, and improved cardiac function during ischemia. PAD2 is promising as a future therapeutic target for the treatment of HS and cardiac ischemia.

Alliance A041701 - a Randomized Phase 2/3 Study of Conventional Chemotherapy +/- Uproleselan (GMI-1271) in Older Adults with Acute Myeloid Leukemia (AML) Receiving Intensive Induction Chemotherapy

Uproleselan (GMI-1271) is a novel antagonist of E-selectin, an adhesion molecule expressed on endothelial cells. E-selectin is expressed transiently in the normal vasculature during an inflammatory response and constitutively in the bone marrow (BM). Binding of E-selectin (E-sel) to sialyl Lex, the E-sel ligand (E-sel-L), on the leukemic cell surface activates cell survival pathways and promotes chemotherapy resistance in AML. In preclinical models, blockade of E-selectin with uproleselan disrupts the activation of cell survival pathways and enhanced the efficacy of chemotherapy across multiple AML tumor models. Furthermore, uproleselan protected against chemotherapy-induced mucositis by regulating macrophage trafficking to the site of injury in the gut lining. A previous phase I/II study of uproleselan added to chemotherapy in patients with untreated AML (older adults ≥60 yrs) and relapsed/refractory AML (≥ 18yrs) showed promising remission rates (CR/CRi) and survival outcomes, and reduced rates of mucositis. In the newly diagnosed older patients, high remission rates were achieved overall (CR/CRi 72%) and for the high risk subgroup with sAML (CR/CRi 69%). In this phase 2/3 study, we will test the addition of uproleselan to a standard daunorubicin/cytarabine regimen in older adults with previously untreated AML. The study will enroll patients age ≥ 60 yrs with untreated acute myeloid leukemia. Patients with acute promyelocytic leukemia, activating mutations in FLT3, or evidence of central nervous system involvement are excluded. Subjects are randomized to 7+3 induction (cytarabine + daunorubicin) +/- uproleselan. Subjects achieving a CR/CRi may receive up to 3 cycles of consolidation with intermediate dose cytarabine 2 gm/m2 IV d1-5 +/- uproleselan. The primary phase II objective is to compare the event-free survival (EFS). A sample size of 262 patients was selected for the phase II to detect an improvement in median EFS from 7 months to 11 months (HR= 0.64) with &amp;gt; 95% power, using a log rank test. The phase III primary objective will compare overall survival (OS). For the phase III, a sample size of 335 evaluable patients per arm (670 total inclusive of patients enrolled in phase II) will provide &amp;gt;90% power to detect an improvement in median OS from 12 months to 16 months (HR= 0.75), using a log-rank test. Correlative studies will measure E-selectin ligand on AML blasts and soluble E-selectin and will also measure minimal residual disease after remission induction by multiparameter flow cytometry. A comprehensive geriatric assessment will identify baseline measures associated with EFS and develop a risk model to predict OS among older adults receiving intensive AML therapy. The study is endorsed by SWOG and ECOG-ACRIN and opened to enrollment on 1/16/2019. Figure Disclosures Uy: Astellas: Consultancy; Pfizer: Consultancy; Curis: Consultancy; GlycoMimetics: Consultancy. Dinner:Agios: Consultancy; Pfizer: Consultancy; AstraZeneca: Consultancy. Strickland:Jazz: Consultancy; Sunesis Pharmaceuticals: Research Funding; Pfizer: Consultancy; Kite: Consultancy; Astellas Pharma: Consultancy; AbbVie: Consultancy. Liesveld:Onconova: Other: Data safety monitoring board; Abbvie: Membership on an entity's Board of Directors or advisory committees. Byrd:Acerta: Research Funding; Acerta: Research Funding; Genentech: Research Funding; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Ohio State University: Patents &amp; Royalties: OSU-2S; BeiGene: Research Funding; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; BeiGene: Research Funding; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; BeiGene: Research Funding; Novartis: Other: Travel Expenses, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; Genentech: Research Funding; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Acerta: Research Funding; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Ohio State University: Patents &amp; Royalties: OSU-2S; Ohio State University: Patents &amp; Royalties: OSU-2S; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau. Stone:Argenx, Celgene, Takeda Oncology: Other: Data and Safety Monitoring Board/Committee: ; AbbVie, Actinium, Agios, Argenx, Arog, Astellas, AstraZeneca, Biolinerx, Celgene, Cornerstone Biopharma, Fujifilm, Jazz Pharmaceuticals, Amgen, Ono, Orsenix, Otsuka, Merck, Novartis, Pfizer, Sumitomo, Trovagene: Consultancy; Novartis, Agios, Arog: Research Funding. OffLabel Disclosure: Uproleselan in AML

A Double-Blind, Placebo-Controlled, Phase 3 Registration Trial to Evaluate the Efficacy of Uproleselan (GMI-1271) with Standard Salvage Chemotherapy in Patients with Relapsed/Refractory (R/R) Acute Myeloid Leukemia

A Double-Blind, Placebo-Controlled, Phase 3 Registration Trial to Evaluate the Efficacy of Uproleselan (GMI-1271) with Standard Salvage Chemotherapy in Patients with Relapsed/Refractory (R/R) Acute Myeloid Leukemia

Biomarker-based assessment of the muscle maintenance and energy status of anurans from an extremely seasonal semi-arid environment, the Brazilian Caatinga

Strongly seasonal environments pose challenges for performance and survival of animals, especially when resource abundance seasonally fluctuates. We investigated the seasonal variation of key metabolic biomarkers in the muscles of males from three species (Rhinella jimi, R. granulosa and Pleurodema diplolister) of anurans from the drastically seasonal Brazilian semi-arid area, Caatinga. We examined the expression of proteins regulating energy turnover (AMP-activated protein kinase [AMPK] and protein kinase B [AKT]), protein synthesis and homeostasis (total and phosphorylated eukaryotic initiation factor 2α [eIF2α and p-eIF2α] and chaperone proteins [HSP 60, 70, and 90]) in muscles predominantly related to reproduction and locomotion. Cytochrome c oxidase (COX) activity was also assessed as an index of the muscle aerobic capacity. The expression pattern of metabolic biomarkers indicates that the maintenance of muscular function is regulated in a species-specific manner during the drastic seasonal variation. Rhinella jimi and R. granulosa that remain active during the drought appear to maintain muscles through more energy expensive pathways including elevated protein synthesis, while the aestivating P. diplolister employs energy conservation strategy suppressing protein synthesis, decreasing chaperone expression and increasing expression of AMPK. Two (P. diplolister and R. granulosa) of the three studied species activate cell survival pathways during the drought likely to prevent muscle atrophy, and all three studied species maintain the muscle aerobic capacity throughout the year, despite the resource limitation. These strategies are important considering the unpredictability of the reproductive event and high demand on muscular activity during the reproductive season in these amphibians. Summary statementWe studied seasonal variation of key metabolic biomarkers in the muscles of anurans that experience drastic variation in environmental conditions and differ in seasonal activity patterns.

A phase III trial to evaluate the efficacy of uproleselan (GMI-1271) with chemotherapy in patients with relapsed/refractory acute myeloid leukemia.

TPS7066 Background: Binding of E-selectin (E-sel) to sialyl Lex, the E-sel ligand (E-sel-L), on the leukemic cell surface activates cell survival pathways and promotes chemotherapy resistance in AML. Expression of E-sel-L is associated with increased relapse and poor survival. Uproleselan (GMI-1271), a novel E-sel antagonist, disrupts cell survival pathway activation, enhances chemotherapy response and protects from toxicity such as mucositis with improved survival in vivo. Preclinical data support combination with multiple agents to achieve improved chemosensitivity and toxicities. A phase I/II study of uproleselan added to chemotherapy in R/R AML showed promising remission rates (CR/CRi) and survival outcomes, and reduced rates of mucositis. High E-sel-L expression on leukemic blasts in the bone marrow, rather than connoting treatment resistance and poor survival, instead correlated with longer survival than expected with addition of uproleselan. Breakthrough Therapy Designation was granted by FDA for treatment of patients with R/R AML. A pivotal phase 3 study (NCT03616470) is underway to assess the efficacy and safety of uproleselan with standard salvage chemotherapy in R/R AML. Methods: This study is a global, randomized, double-blind, phase 3 trial in adults aged 18-75 years with R/R AML and fit for chemotherapy. Patients may have primary refractory AML (received 1 prior induction containing an anthracycline and cytarabine), or be in untreated first or second relapse; prior HSCT is allowed. Treatment is MEC (mitoxantrone, etoposide, cytarabine) or FAI (fludarabine, cytarabine, idarubicin) induction regimen with blinded study drug (Uproleselan:placebo at 1:1 ratio) administered 1 day prior (sentinel dose) and then BID through 2 days post chemotherapy. Consolidation (HIDAC/IDAC) with uproleselan/placebo (same assignment) up to 3 cycles is allowed. The primary endpoint is overall survival; key secondary endpoints include the incidence of severe oral mucositis during induction and CR/CRh rate. Measurable residual disease, E-sel-L expression on leukemic cells, event free survival, safety, and pharmacokinetics will also be evaluated. Clinical trial information: NCT03616470.

A Novel and Potent Inhibitor of E-Selectin, GMI-1687, Attenuates Thrombus Formation and Augments Chemotherapeutic Intervention of AML in Preclinical Models Following Subcutaneous Administration

Abstract Uproleselan (GMI-1271), an E-selectin antagonist, has been shown in preclinical models to disrupt activation of cell survival pathways in acute myeloid leukemia (AML), enhance chemotherapy efficacy, and improve survival. Uproleselan received FDA breakthrough therapy designation for adult relapsed/refractory AML in 2017 and Phase III studies are ongoing. In the present studies we report on the in vitro and in vivo comparative activities of an innovative high potency E-selectin antagonist, GMI-1687, a potential subcutaneously administered follow-on drug candidate to Uproleselan. The binding constant, association and dissociation rates of GMI-1687 to immobilized recombinant human (rh) E-selectin were determined by surface plasmon resonance (SPR) at 25oC. The KD of GMI-1687 was 2.4 nM, with Kon = 3 x 106 M-1s-1 and Koff = 1 x10-2 s-1. Under similar experimental conditions the KD of Uproleselan was 520 nM with Kon = 0.02 x 106 M-1s-1 and Koff = 1 x10-2 s-1. GMI-1687 was evaluated for its ability to inhibit binding of sialyl Lea to immobilized rh E-selectin. The median IC50 (n=6 independent assays) of GMI-1687 and Uproleselan in this assay was 15 and 550 nM, respectively. The in vitro activity of GMI-1687 to release adherent KG1a AML cells from E-selectin coated wells was also determined. GMI-1687 at 100 nM detached approximately 55% of adherent AML cells and was significantly different from Uproleselan at an identical concentration (38% detachment, P=0.0216). The percent bioavailability (%F) of GMI-1687 was evaluated in male Sprague-Dawley rats following intravenous (IV) and subcutaneous (SC) routes of administration at 5 mg/kg. The mean (+/- SD) SC %F for GMI-1687 was 126 +/- 3.8%. GMI-1687 also showed high bioavailability in CD-1 mice after SC administration of 0.58 mg/kg with %F = 132 +/-38. The in vivo therapeutic activity of GMI-1687 following SC administration was assessed in an acute model of inferior vena cava (IVC) thrombosis and a tumor model of AML.Immediately following the induction of a non-occlusive thrombosis via electrical stimulation (250 mAmp) of the IVC, cohorts of male C57BL/6J mice (n=5/group) were given a single SC injection of saline (0.1 mL); Uproleselan (40 mg/kg); or GMI-1687 (4 mg/kg, 0.4 mg/kg or 0.04 mg/kg), and twenty-four hrs post thrombus induction the IVC was harvested from all mice and thrombus weights were determined. Treatment with GMI-1687 decreased thrombus formation with significant inhibition at 0.04 mg/kg (92%, P&lt;0.001 compared to saline control). The inhibition of thrombus formation with GMI-1687 dosed at 0.04 mg/kg was statistically indistinguishable from Uproleselan administered SC at 40 mg/kg (97% inhibition). The therapeutic activity of SC GMI-1687 was also observed in combination with chemotherapy in a U937 tumor model. Three days post IV injection of U937 tumor cells, bone marrow ablated, female NOD/SCID mice (n=10/group) were treated with saline (0.1 mL SC QDx14); GMI-1687 (0.04 mg/kg SC QDx14) alone; cytarabine (AraC 300 mg/kg IP QDx3) + daunorubicin (DNR 3 mg/kg IV QDx1), or the combination of GMI-1687 and AraC + DNR. All treatments were well tolerated. The median survival time (MST) of mice treated with AraC + DNR was 36 days and statistically different (P&lt;0.001) to groups treated with saline (MST=22 days) or GMI-1687 alone (MST=23 days). Importantly, the therapeutic activity of AraC+DNR was significantly enhanced when combined with GMI-1687 (MST&gt;47.5 days, P=0.0153 compared to AraC+DNR alone). In summary, a highly potent innovative antagonist of E-selectin, GMI-1687, has been produced that demonstrates high bioavailability following SC administration. SC injection of GMI-1687 shows significant activity in preclinical models previously reported for parenteral administration of Uproleselan, but at approximately 250-fold lower dose. GMI-1687 is therefore well-positioned for potential use in outpatient treatment settings where an E-selectin antagonist has therapeutic relevance. IND-enabling studies with GMI-1687 are currently underway. Disclosures Peterson: GlycoMimetics: Employment, Equity Ownership. Baek:GlycoMimetics: Employment, Equity Ownership. Locatelli-Hoops:GlycoMimetics: Employment, Equity Ownership. Lee:GlycoMimetics: Employment, Equity Ownership. Deng:GlycoMimetics: Employment, Equity Ownership. Stewart:GlycoMimetics: Employment, Equity Ownership. Smith:GlycoMimetics: Employment, Equity Ownership. Fogler:GlycoMimetics: Employment, Equity Ownership. Magnani:GlycoMimetics: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees.

Uproleselan (GMI-1271), an E-Selectin Antagonist, Improves the Efficacy and Safety of Chemotherapy in Relapsed/Refractory (R/R) and Newly Diagnosed Older Patients with Acute Myeloid Leukemia: Final, Correlative, and Subgroup Analyses

Background Binding of E-selectin (E-sel) to sialyl Lex on the leukemic cell surface activates cell survival pathways and promotes chemotherapy resistance in AML. Expression of the E-sel ligand (E-sel-L) is associated with increased relapse and poor survival. Uproleselan (GMI-1271), a novel E-sel antagonist, disrupts cell survival pathway activation, enhances chemotherapy response and protects from toxicity with improved survival in vivo. We added uproleselan to mitoxantrone, etoposide, cytarabine (MEC) chemotherapy for R/R AML patients (pts) and to cytarabine and idarubicin (7+3) induction for older, treatment naive (TN) AML pts. Here we report on final outcomes and correlative studies. Methods A Phase (Ph) 1/2 trial evaluated safety and efficacy of escalating doses of upro (5-20 mg/kg) combined with MEC in pts with R/R AML. The recommended Ph 2 dose (RP2D) was 10 mg/kg. Ph 2 added pts ≥60 yrs with TN AML treated with upro and 7+3. Uproleselan was given 24 hrs prior, every 12 hrs during and 48 hrs post chemotherapy. Responders could receive consolidation therapy (1 cycle MEC or 1-3 cycles IDAC) with uproleselan. Baseline E-sel-L expression on AML blasts (CD45+,SSC) and leukemic stem cells (LSC, CD34+CD38-CD123+) in blood and bone marrow (BM) was assessed by flow cytometry, for percentage of blasts binding to E-sel-Fc chimeric protein and HECA452 (antibody to sialyl Lex). Post-induction measurable residual disease (MRD-/MRD+) was assessed locally. Results 91 pts were enrolled (Ph 1 R/R=19; Ph 2 R/R=47. TN=25). Median age in R/R pts was 59 yrs (26-84) with 22/66 (33%) primary refractory, 22 (33%) CR1 Median age in TN pts was 67 yrs (60-79). 48% had adverse risk (ELN) and 52% secondary AML (sAML). Uproleselan was well tolerated, with no increase in adverse events, no Grade 3/4 mucositis, and mortality 8% (30d) and 12% (60d). CR/CRi was 72% (all), and 69% (sAML). 5/9 (56%) evaluable pts were MRD-. 19/25 (76%) proceeded to further anti-leukemic therapy; 11 (44%) proceeded to SCT. Median (95% CI) EFS, OS, and remission duration were 9.2 m (3.0-12.6), 12.6 m (9.9-NR), and 10.4 m (7.1-17.8) respectively; 1-year OS was 52%. For sAML, median (95% CI) EFS and OS were 7.7 m (1.1-9.5) and 10.5m (4.4-NR), respectively. For TN/MRD-, 1-year OS was 60%. E-sel-L was detectable on BM blasts in all 24 evaluable pts: median expression 31% (2-92) of blasts. In a subset of MRD evaluable pts (N=8), E-sel-L expression was higher in those who were MRD+ (35% vs 8%). In BM blasts (Figure N=24), LSC expression of E-sel-L correlated with blast E-sel-L (R2=0.87, p Conclusion The addition of uproleselan to chemotherapy was well tolerated, with low oral mucositis rates, high remission rates, high MRD- and transplant rates, and promising survival outcomes in pts with R/R and TN AML. High E-sel-L expression is associated with improved remission and survival with uproleselan treatment in R/R AML. Phase III studies in pts with R/R and (older) TN AML are underway. Disclosures DeAngelo:Shire: Honoraria; Amgen: Consultancy; BMS: Consultancy; ARIAD: Consultancy, Research Funding; Blueprint Medicines: Honoraria, Research Funding; Takeda: Honoraria; Glycomimetics: Research Funding; Novartis Pharmaceuticals Corporation: Consultancy, Honoraria; Amgen: Consultancy; Novartis Pharmaceuticals Corporation: Consultancy, Honoraria; Incyte: Consultancy, Honoraria; Glycomimetics: Research Funding; Blueprint Medicines: Honoraria, Research Funding; Pfizer Inc: Consultancy, Honoraria; Shire: Honoraria; BMS: Consultancy; Takeda: Honoraria; Incyte: Consultancy, Honoraria; Pfizer Inc: Consultancy, Honoraria; ARIAD: Consultancy, Research Funding. Jonas:Glycomimetics: Research Funding; Genentech/Roche: Research Funding; Celgene: Consultancy, Research Funding; Accelerated Medical Diagnostics: Research Funding; Daiichi Sankyo: Research Funding; Incyte: Research Funding; Esanex: Research Funding; Tolero: Consultancy; Kalobios: Research Funding; LP Therapeutics: Research Funding; Amgen: Consultancy; Pharmacyclics: Research Funding; Forma: Research Funding; AbbVie: Consultancy, Research Funding. Liesveld:Onconova: Other: DSMB; Abbvie: Honoraria. Bixby:GlycoMimetics: Research Funding. Advani:Glycomimetics: Consultancy; Novartis: Consultancy; Amgen: Research Funding; Pfizer: Honoraria, Research Funding. Marlton:GlycoMimetics: Research Funding; Novartis: Honoraria, Membership on an entity9s Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity9s Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity9s Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity9s Board of Directors or advisory committees; Astellas: Honoraria, Membership on an entity9s Board of Directors or advisory committees; Celgene: Membership on an entity9s Board of Directors or advisory committees; Pfizer: Membership on an entity9s Board of Directors or advisory committees. O9Dwyer:Janssen: Membership on an entity9s Board of Directors or advisory committees, Research Funding; BMS: Research Funding; Onkimmune: Equity Ownership, Membership on an entity9s Board of Directors or advisory committees, Research Funding; Celgene: Research Funding; Glycomimetics: Research Funding; Abbvie: Membership on an entity9s Board of Directors or advisory committees. Fogler:GlycoMimetics: Employment, Equity Ownership. Wolfgang:GlycoMimetics: Employment, Equity Ownership. Magnani:GlycoMimetics: Employment, Equity Ownership, Membership on an entity9s Board of Directors or advisory committees. Thackray:GlycoMimetics: Employment, Equity Ownership. Becker:GlycoMimetics: Research Funding.