Triple negative breast cancer (TNBC) is the most aggressive breast cancer subtype. It accounts for ~15% of all breast cancer yet is responsible for 30% of breast cancer deaths. TNBC is treated primarily by conventional chemotherapy; however, resistance to therapy is common, leading to high mortality rates. Importantly, the benefit of current therapeutic strategies used in chemoresistant TNBC; i.e., immunotherapy and antibody- drug conjugates, is confined to only a fraction of patients, and survival benefit is limited. Therefore, there is an urgent need to identify novel and effective treatment strategies to overcome resistance to chemotherapy. Recently, we identified hypoxia-induced ECM re-modeler, lysyl oxidase (LOX) as a key mediator of chemoresistance in TNBC (Saatci et al, Nature Communications, 2020). We showed that LOX is overexpressed in chemoresistant tumors, and its inhibition re-sensitizes the most aggressive breast tumors to doxorubicin using several clinically-relevant mouse models. However, the available LOX inhibitors are either non-selective or has toxicity. Hence, our main objective in this project is to develop potent, specific and well-tolerated LOX inhibitors to overcome chemoresistance in TNBC that has a high translational potential. Through high-throughput compound library screening and hit-to-lead conversion studies, we identified compounds with potent on-target cellular engagement of LOX, with good oral pharmacokinetics (PK) and with chemosensitizer effect without major toxicity (US PTO 17/693, 371 and PCT/US2022/20086, patent pending). Starting from our current non-optimized lead molecule, we aim to develop lead compounds with increased potency, safety and drug-likeness. To accomplish this goal, in Phase I of this Fast-Track STTR grant, we will generate a diverse library of small molecules via an extensive structure activity relationship (SAR) study using our initial pharmacophore. We will test the synthesized inhibitors with respect to the degree of LOX enzymatic activity inhibition, LOX binding and selectivity towards LOX. We will perform the off-target assessment of the inhibitors using CEREP screen as well as kinome profiling. The shortlisted candidates will further be tested in ECM crosslinking and 3D chemosensitization assays using both cell lines and organoids. Inhibitors with better efficacy, selectivity and stability will move to Phase II. In Phase II, we will perform several ADME assays, including metabolic stability/identity, Caco-2 permeability and transport, cardiotoxicity and genotoxicity, plasma protein binding, CYP inhibition/induction/reaction phenotyping to improve drug-like properties while maintaining on-target potency in TNBC cells. Detailed PK/PD and toxicity analyses of the most promising candidates will be carried out followed by testing their chemosensitizer effect using both state-of-the-art immunodeficient (cell line- and patient-derived xenografts) and immunocompetent (syngeneic) mice models. The successful completion of the proposed project will lead to potent and specific, lead-optimized LOX inhibitors to overcome chemoresistance in TNBC, the deadliest form of breast cancer.
Public Health Relevance Statement: NARRATIVE The proposed project is relevant to public health because the goal is to develop novel and highly potent LOX inhibitors to overcome chemotherapy resistance in triple negative breast cancer (TNBC), a highly aggressive subpopulation of breast cancer with worse survival. Once we develop LOX inhibitors with excellent drug-like properties, there is a significant potential to improve the treatment of chemotherapy-resistant TNBC patients with high LOX expression. Thus, the proposed project is relevant to the part of the NIH's mission that pertains to reducing illness and disability. Terms: inhibitor; Biological Assay; Assay; Bioassay; Biologic Assays; Biological Availability; Bioavailability; Physiologic Availability; Biometry; Biometrics; Biostatistics; malignant breast neoplasm; Breast Cancer; malignant breast tumor; Cell Line; CellLine; Strains Cell Lines; cultured cell line; Cells; Cell Body; Pharmaceutical Chemistry; Medicinal Chemistry; Pharmaceutic Chemistry; Collagen; Communication; Complement; Complement Proteins; Cessation of life; Death; Dedications; Canis familiaris; Canine Species; Dogs; Dogs Mammals; canine; domestic dog; Doxorubicin; 14-Hydroxydaunomycin; Adriamycine; Doxorubicina; Hydroxyl Daunorubicin; Hydroxyldaunorubicin; Pharmaceutical Preparations; Drugs; Medication; Pharmaceutic Preparations; drug/agent; Extracellular Matrix; Cell-Extracellular Matrix; ECM; Fibronectins; Cold-Insoluble Globulins; FN1; Fibronectin 1; LETS Proteins; Large External Transformation-Sensitive Protein; Opsonic Glycoprotein; Opsonic alpha(2)SB Glycoprotein; alpha 2-Surface Binding Glycoprotein; Goals; Grant; Immunologic Deficiency Syndromes; Immunodeficiency Disorder; Immunodeficiency Syndrome; Immunological Deficiency Syndromes; hypoimmunity; immune deficiency disorder; immunodeficiency; Immunotherapy; Immune mediated therapy; Immunologically Directed Therapy; immune therapeutic approach; immune therapeutic interventions; immune therapeutic regimens; immune therapeutic strategy; immune therapy; immune-based therapies; immune-based treatments; immuno therapy; In Vitro; Lead; Pb element; heavy metal Pb; heavy metal lead; Libraries; Protein-Lysine 6-Oxidase; Collagen Lysyl Oxidase; EC 1.4.3.13; Lysyl Oxidase; Medical Oncology; Mission; Monoamine Oxidase; Tyramine Oxidase; adrenalin oxidase; tyraminase; mortality; Mus; Mice; Mice Mammals; Murine; United States National Institutes of Health; NIH; National Institutes of Health; Organoids; Legal patent; Patents; Patients; Permeability; Drug Kinetics; Pharmacokinetics; Phenotype; Phosphotransferases; Kinases; Phosphotransferase Gene; Transphosphorylases; Plasma Proteins; Public Health; Safety; Serum Proteins; Signal Transduction; Cell Communication and Signaling; Cell Signaling; Intracellular Communication and Signaling; Signal Transduction Systems; Signaling; biological signal transduction; Solubility; Specificity; Structure-Activity Relationship; chemical structure function; structure function relationship; Testing; Time; crosslink; improved; Penetration; Phase; disability; Hypoxic; Oxygen Deficiency; Hypoxia; Ligand Binding Protein; Ligand Binding Protein Gene; Protein Binding; bound protein; Binding Proteins; Chemosensitization/Potentiation; Potentiation; Chemosensitization; Therapeutic; Metabolic; Nature; Oral; Reaction; 3-Dimensional; 3-D; 3D; three dimensional; meter; Benchmarking; Best Practice Analysis; benchmark; chemosensitizing agent; MDR Modulators; Multidrug Resistance Modifier; Multidrug Resistance Modulator; Multidrug-Resistance Antagonists; Multidrug-Resistance Chemo Sensitizers; Multidrug-Resistance Inhibitors; chemopotentiating agent; chemosensitizer; success; small molecule libraries; chemical library; genotoxicity; synergism; pharmacophore; cellular targeting; Toxic effect; Toxicities; novel; member; Maximum Tolerated Dose; Maximal Tolerated Dose; Maximally Tolerated Dose; breast surgery; Pharmacodynamics; Modeling; Property; Cardiotoxicity; Cardiac Toxicity; Cardiotoxic; drug discovery; Molecular Interaction; Binding; protein expression; Induction of Apoptosis; PTK2 gene; FADK; FAK; FAK1; PTK2; pp125FAK; Address; Mammary Neoplasms; Breast Neoplasms; Breast Tumors; Mammary Cancer; mammary tumor; Breast Cancer Model; Breast tumor model; mammary cancer model; mammary tumor model; Breast Cancer Cell; breast tumor cell; Immunocompetent; immune competent; in vitro Assay; in vivo; mRNA Expression; Cancer Biology; Small Business Technology Transfer Research; STTR; Modification; triple-negative invasive breast carcinoma; TNBC; triple-negative breast cancer; therapy resistant; resistance to therapy; resistant to therapy; therapeutic resistance; treatment resistance; designing; design; Outcome; resistant; Resistance; clinical relevance; clinically relevant; chemotherapy; murine model; mouse model; tumor; overexpress; overexpression; treatment strategy; effective treatment; effective therapy; drug candidate; screenings; screening; Breast tumor cell line; Breast Cancer cell line; Breast Tumor Patient; Breast Cancer Patient; cancer sub-types; cancer subtypes; Antibody-drug conjugates; lead optimization; PK/PD; pharmacokinetics and pharmacodynamics; chemoresistant; chemotherapy resistance; chemotherapy resistant; Chemoresistance; PDX model; Patient derived xenograft; patient derived xenograft model; aggressive breast cancer; translational potential; translational opportunities; Mediator
