lgk974 and Neoplasms

Porcupine is a constituent of the 19 membered Wnt family with diverse biological features such as cell differentiation, cell proliferation, cell migration, apoptosis, etc. Porcupine is a membrane-bound o-acyltransferase family protein that modulates Wnt protein through palmitoylation to allow it to depart the secretory pathway and activate cellular responses. Inhibition of Porcupine prevents palmitoylation of Wnt ligands which in turn blocks the transport of Wnt to the extracellular membrane, thus prevents the immoderate production of β-catenin which helps to control the aberrant cell growth. Clinically, Porcupine inhibitors have shown their potential in treating majorly colorectal cancer, pancreatic cancer, hepatocellular carcinoma, head and neck cancer etc. Till date, none of the Porcupine inhibitors have been in the market and only four molecules, LGK974, ETC159, CGX1321 and RXC004 have reached the Phase I clinical trial. Present review gives a comprehensive insight on Porcupine as a novel drug target for the treatment of cancer as well as recent update on many novel heterocyclic Porcupine inhibitors with their chemical structures and pharmacology. Their physico chemical properties were also predicted using SwissADME server. Major concerns during their development have also been summarised which may throw some light for the future development of novel Porcupine inhibitors for the treatment of cancer.

Topics: Acyltransferases; Animals; Antineoplastic Agents; Drug Development; Drug Discovery; Enzyme Inhibitors; Humans; Membrane Proteins; Molecular Targeted Therapy; Neoplasms; Pyrazines; Pyridines; Wnt Signaling Pathway

Genetically based observations stemming from defects in development and in regeneration form the foundation of our understanding regarding how the secreted WNT proteins control coordinated cell fate decision-making in adult tissues. At the same time, our anticipation of potential benefits and unwanted toxicities associated with candidate anticancer agents targeting WNT signal transduction are also reliant upon this blueprint of WNT-associated physiology. Despite the long established role of WNT signaling in cancer, the emergence of WNT signaling as a suppressor of immunological attack in melanoma reveals an unanticipated anticancer potential in targeting WNT signaling. Here we review the literature associated with WNT signaling in cancer and discuss potential challenges that may be associated with the chemical attack of this important cellular process in achieving therapeutic goals. Although a number of small molecules targeting WNT signaling are introduced here, we center our discussion on antagonists of the WNT acyltransferase porcupine (PORCN) given the recent entry of two candidate molecules in clinical testing.

Topics: Acyltransferases; Humans; Membrane Proteins; Neoplasms; Pyrazines; Pyridines; Wnt Proteins; Wnt Signaling Pathway

Over the past decade, academic groups and pharmaceutical companies have uncovered several components and targets for intervention in the Wnt pathway. One approach is to block Wnt signalling through the use of orally bioavailable small molecules that prevent Wnt ligand secretion. In recent years, the membrane bound O-acyl transferase (MBOAT) porcupine (PORCN) has emerged as a molecular target of interest in the search for clinical options to treat Wnt-driven cancers. This review shall provide an overview of the reported small molecule inhibitors for PORCN and discuss the progress made in identifying human disease models that are responsive to PORCN inhibitors.

Topics: Acyltransferases; Animals; Benzothiazoles; HEK293 Cells; Humans; Membrane Proteins; Molecular Structure; Neoplasms; Wnt Signaling Pathway

This Phase 1 study assessed the safety and efficacy of the Porcupine inhibitor, WNT974, in patients with advanced solid tumours.. Patients (n = 94) received oral WNT974 at doses of 5-30 mg once-daily, plus additional dosing schedules.. The maximum tolerated dose was not established; the recommended dose for expansion was 10 mg once-daily. Dysgeusia was the most common adverse event (50% of patients), likely resulting from on-target Wnt pathway inhibition. No responses were seen by Response Evaluation Criteria in Solid Tumors (RECIST) v1.1; 16% of patients had stable disease (median duration 19.9 weeks). AXIN2 expression by RT-PCR was reduced in 94% of paired skin biopsies (n = 52) and 74% of paired tumour biopsies (n = 35), confirming inhibition of the Wnt pathway. In an exploratory analysis, an inverse association was observed between AXIN2 change and immune signature change in paired tumour samples (n = 8).. Single-agent WNT974 treatment was generally well tolerated. Biomarker analyses suggest that WNT974 may influence immune cell recruitment to tumours, and may enhance checkpoint inhibitor activity.. NCT01351103.

Topics: Administration, Oral; Adult; Aged; Axin Protein; Enzyme Inhibitors; Female; Gene Expression Regulation, Neoplastic; Humans; Male; Middle Aged; Neoplasms; Pyrazines; Pyridines; Treatment Outcome; Wnt Signaling Pathway

WNT974 is a potent, selective, and orally bioavailable first-in-class inhibitor of Porcupine, a membrane-bound O-acyltransferase required for Wnt secretion, currently under clinical development in oncology. A phase I clinical trial is being conducted in patients with advanced solid tumors. During the dose-escalation part, various dosing regimens, including once or twice daily continuous and intermittent dosing at a dose range of 5-45 mg WNT974 were studied, however, the protocol-defined maximum tolerated dose (MTD) was not established based on dose-limiting toxicity. To assist in the selection of the recommended dose for expansion (RDE), a model-based approach was utilized. It integrated population pharmacokinetic (PK) modeling and exposure-response analyses of a target-inhibition biomarker, skin AXIN2 mRNA expression, and the occurrence of the adverse event, dysgeusia. The target exposure range of WNT974 that would provide a balance between target inhibition and tolerability was estimated based on exposure-response analyses. The dose that was predicted to yield an exposure within the target exposure range was selected as RDE. This model-based approach integrated PK, biomarker, and safety data to determine the RDE and represented an alternative as opposed to the conventional MTD approach for selecting an optimal biological dose. The strategy can be broadly applied to select doses in early oncology trials and inform translational clinical oncology drug development.

Topics: Antineoplastic Agents; Dose-Response Relationship, Drug; Humans; Maximum Tolerated Dose; Neoplasms; Pyrazines; Pyridines; Treatment Outcome

Wnt signalling is essential for regulation of embryonic development and adult tissue homeostasis

Topics: Acylation; Acyltransferases; Antineoplastic Agents; Binding Sites; Coenzyme A; Cryoelectron Microscopy; Histidine; Humans; Membrane Proteins; Neoplasms; Palmitoyl Coenzyme A; Pyrazines; Pyridines; Serine; Substrate Specificity; Wnt Signaling Pathway; Wnt3A Protein

The DNA repair enzyme O6-methylguanine-DNA methyltransferase (MGMT) is commonly overexpressed in cancers and is implicated in the development of chemoresistance. The use of drugs inhibiting MGMT has been hindered by their haematologic toxicity and inefficiency. As a different strategy to inhibit MGMT we investigated cellular regulators of MGMT expression in multiple cancers. Here we show a significant correlation between Wnt signalling and MGMT expression in cancers with different origin and confirm the findings by bioinformatic analysis and immunofluorescence. We demonstrate Wnt-dependent MGMT gene expression and cellular co-localization between active β-catenin and MGMT. Pharmacological or genetic inhibition of Wnt activity downregulates MGMT expression and restores chemosensitivity of DNA-alkylating drugs in mouse models. These findings have potential therapeutic implications for chemoresistant cancers, especially of brain tumours where the use of temozolomide is frequently used in treatment.

Topics: Animals; Antineoplastic Agents; Benzeneacetamides; beta Catenin; Brain Neoplasms; Camptothecin; Celecoxib; Cisplatin; Colorectal Neoplasms; Dacarbazine; DNA Modification Methylases; DNA Repair Enzymes; Doxorubicin; Drug Resistance, Neoplasm; Flow Cytometry; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Glioma; Glucose-6-Phosphate Isomerase; Heterocyclic Compounds, 3-Ring; Humans; Immunoblotting; Immunohistochemistry; Irinotecan; Medulloblastoma; Mice; Neoplasm Transplantation; Neoplasms; Neuroblastoma; Pyrans; Pyrazines; Pyridines; Real-Time Polymerase Chain Reaction; Sulfones; Temozolomide; Triazoles; Tumor Suppressor Proteins; Vincristine; Wnt Proteins; Wnt Signaling Pathway

Wnt signaling is one of the key oncogenic pathways in multiple cancers, and targeting this pathway is an attractive therapeutic approach. However, therapeutic success has been limited because of the lack of therapeutic agents for targets in the Wnt pathway and the lack of a defined patient population that would be sensitive to a Wnt inhibitor. We developed a screen for small molecules that block Wnt secretion. This effort led to the discovery of LGK974, a potent and specific small-molecule Porcupine (PORCN) inhibitor. PORCN is a membrane-bound O-acyltransferase that is required for and dedicated to palmitoylation of Wnt ligands, a necessary step in the processing of Wnt ligand secretion. We show that LGK974 potently inhibits Wnt signaling in vitro and in vivo, including reduction of the Wnt-dependent LRP6 phosphorylation and the expression of Wnt target genes, such as AXIN2. LGK974 is potent and efficacious in multiple tumor models at well-tolerated doses in vivo, including murine and rat mechanistic breast cancer models driven by MMTV-Wnt1 and a human head and neck squamous cell carcinoma model (HN30). We also show that head and neck cancer cell lines with loss-of-function mutations in the Notch signaling pathway have a high response rate to LGK974. Together, these findings provide both a strategy and tools for targeting Wnt-driven cancers through the inhibition of PORCN.

Topics: Acyltransferases; Animals; Axin Protein; Blotting, Western; Cell Line, Tumor; Cloning, Molecular; High-Throughput Screening Assays; Humans; Membrane Proteins; Mice; Mutagenesis; Neoplasms; Phosphorylation; Pyrazines; Pyridines; Radioligand Assay; Rats; Receptors, Notch; Reverse Transcriptase Polymerase Chain Reaction; Wnt Signaling Pathway