PF-543 / Pfizer - LARVOL DELTA

A commensal protozoan exacerbates acetaminophen-induced liver injury by producing free sphingosine. (PubMed, Gut Microbes) - "Inhibiting sphingosine kinases (SPHKs) with PF543 or K145, or antagonizing sphingosine 1-phosphate receptor (S1PR) with FTY720, abolished the effect of T. mu-mediated exacerbation of acetaminophen (APAP)-induced liver injury (AILI), pointing to a sphingosine-SPHK1/2-S1P-S1PR axis underlying T. mu's remote modulation of hepatic drug sensitivity. In this model, T. mu synthesizes sphingosine by using oxaloacetate, likely generated via the glyoxylate cycle, as a two‑carbon unit donor, rather than directly employing intact palmitic acid to supply the long‑chain carbon skeleton. Collectively, these findings not only deepen our understanding of how the gut microbiota, particularly the underappreciated gut protists, influence extra-intestinal disease outcomes via the gut-distal organ axis, but also reveal the tip of the iceberg regarding the unique metabolic pathways of gut commensal protists."

Journal • Gastrointestinal Disorder • Hepatology • Liver Failure • SPHK1

Triiodothyronine-driven pro-inflammatory responses of dendritic cells are restrained by sphingolipid signaling. (PubMed, J Endocrinol) - "To modulate the S1P pathway, PF-543 (SK1 inhibitor), S1P, or FTY720 (S1PR functional antagonist) were added prior to T3. Although the SK1/S1P/S1PR axis did not alter T cell proliferation, S1PR inhibition increased IFN-γ, and inhibition of either SK1 or S1PRs enhanced IL-17 secretion by splenocytes. Altogether, these findings suggest that a complex sphingolipid-mediated signaling network modulates the immunostimulatory effects of T3 on DCs and the driven adaptive immunity."

Journal • Inflammation • IFNG • IL17A • IL6 • SPHK1

S1PR1-Overexpressing Membrane-Coated Nanoparticles Inhibit Dedifferentiation Progression for the Treatment of Anaplastic Thyroid Carcinoma by Targeting the ACER3/SPHK1/S1P Pathway. (PubMed, Adv Healthc Mater) - "In vivo, CMOE@PLGA@PF543 exhibited enhanced tumor-targeting accumulation, excellent biosafety, and potent inhibition of tumor growth by suppressing the ACER3/SPHK1/S1P axis. These findings reveal a novel molecular mechanism driving ATC progression and offer a targeted nanotherapeutic strategy with strong potential for clinical translation."

Journal • Oncology • Solid Tumor • Thyroid Gland Anaplastic Carcinoma • Thyroid Gland Carcinoma • S1PR1 • SPHK1

Sphingosine-1-phosphate induces pulmonary artery smooth muscle cell proliferation, migration and pulmonary arterial remodeling by modulating sonic hedgehog signaling effector FoxM1. (PubMed, Chin Med J (Engl)) - "S1P/STAT3/Shh/Gli1/FoxM1 pathway plays an important role in PASMCs proliferation and pulmonary arterial remodeling. Targeting this cascade may have potential value for the management of PAH."

Journal • Brain Cancer • Cardiovascular • Glioma • Hypertension • Oncology • Pulmonary Arterial Hypertension • Pulmonary Disease • Respiratory Diseases • Solid Tumor • FOXM1 • GLI1 • SHH • SPHK1

Glyoxylic Acid-Induced Calcium Oxalate Crystal Deposition Drives Nephrotoxicity via SPHK1-Mediated Ferroptosis: Insights from Untargeted Lipidomics. (PubMed, Chem Biol Interact) - "Furthermore, in vivo administration of PF543 (1.0 mg/kg, 2.5 mg/kg) reduced renal CaOx deposition and mitigated GA-induced renal injury. Our findings unveil profound renal lipid dysregulation in GA-induced nephrotoxicity and establish the SPHK1-ferroptosis axis as a pivotal mechanistic link and a promising therapeutic target for counteracting this chemical-induced renal damage."

Journal • Inflammation • Metabolic Disorders • Nephrology • Renal Calculi • Renal Disease • ACSL4 • FTH1 • GPX4 • SPHK1

Single-Cell Transcriptomics Identifies a Pivotal Role of SPHK1+ Macrophage-Driven Inflammation in Mechanism of Aortic Dissection and Highlights SPHK1 as a Therapeutic Target. (PubMed, Inflammation) - No abstract available

Journal • Inflammation • SPHK1

Inhibition of PKM2 lactylation by geniposide ameliorates synovial hyperplasia in experimental arthritis. (PubMed, Eur J Pharmacol) - "Investigations revealed that PF543, an inhibitor of SphK1, and A-485, an inhibitor of p300, inhibited the lactylation of PKM2...It was also found the suppression of glycolysis by GE was counteracted by both lactate and CTB. These results suggested GE suppressed the abnormal proliferation of FLSs by inhibiting the SphK1/p300-mediated lactylation of PKM2, highlighting a novel treatment strategy for RA."

Journal • Cholera • Immunology • Inflammatory Arthritis • Rheumatoid Arthritis • Rheumatology • PKM • SPHK1 • TNFA

Targeting Leishmania donovani Sphingosine Kinase 1 using PF-543 enhances immune response and limits parasite load. (PubMed, PLoS Negl Trop Dis) - "PF-543 exerts moderate direct inhibition of parasite SphK1 while prominently modulating host SphK1-dependent immune and apoptotic pathways, collectively restricting Leishmania survival. Rather than functioning as a parasite-selective inhibitor, PF-543 acts as a dual host-parasite modulator. These findings provide proof-of-concept evidence that simultaneous targeting of sphingolipid signalling in both host and parasite can enhance anti-leishmanial efficacy and support further exploration of SphK-based combination therapeutic strategies."

Journal • Immune Modulation • Immunology • IL10 • IL12A • SPHK1 • TNFA

Sphingosine-1-Phosphate/Protein Kinase Cβ2 Signaling Mediates Hypercontraction of Mesenteric Arterial Smooth Muscle in Spontaneously Hypertensive Rats. (PubMed, J Cardiovasc Pharmacol) - "LY333531, a PKCβ inhibitor, attenuated contraction induced by norepinephrine and S1P in SHR. S1P significantly increased PKCβ2 phosphorylation in SHR, an effect suppressed by sphingosine kinase 1 inhibitor PF-543...These findings demonstrate that S1P activates PKCβ2 via S1P2 and S1P3, enhancing calcium sensitization pathway and promoting hypercontraction in SHR. Thus, the S1P/PKCβ2 pathway is a potential therapeutic target for hypertensive vascular dysfunction."

Journal • Preclinical • Cardiovascular • Hypertension • PRKCB • SPHK1

H3K18 lactylation-mediated SPHK1-SIRT1 feedback loop accelerates pyroptosis of tubular epithelial cells in sepsis-associated acute kidney injury. (PubMed, Theranostics) - "Both SPHK1 knockdown and its inhibitor PF-543 alleviated lactate-augmented pyroptosis...The study identifies an H3K18la-mediated SPHK1-SIRT1 axis as a key factor of RTEC pyroptosis in SA-AKI. The combined pharmacological strategy of NAD+ supplementation and SPHK1 inhibition represents a promising therapeutic strategy for SA-AKI."

Journal • Acute Kidney Injury • Critical care • Infectious Disease • Nephrology • Renal Disease • Septic Shock • KIM1 • NLRP3 • PPARG • SPHK1

Mast cell CRFR1 contributes to pancreatic cancer pain via MAPK/SPHK1 signaling. (PubMed, Pain) - "Importantly, the SPHK1 inhibitor PF543 reduced abdominal hyperalgesia in mice, whereas this effect was abolished in mast cell deficient mice. Moreover, SPHK1 knockdown by siRNA abolished CRFR1-induced mast cell degranulation. These findings highlight the critical role of mast cell CRFR1 in mediating abdominal hyperalgesia and identify the MAPK/SPHK1/S1P axis as an essential pathway, suggesting that targeting mast cell CRFR1 may be a promising therapeutic strategy for managing pancreatic cancer pain."

Journal • Oncology • Pain • Pancreatic Cancer • Pancreatic Ductal Adenocarcinoma • Solid Tumor • SPHK1

SphK1 Suppresses Human Dental Pulp Stem Cell Apoptosis by Promoting Glycolysis Under Simulated Microgravity. (PubMed, J Tissue Eng Regen Med) - "Pharmacological inhibition of SphK1 with PF-543 reduced both glycolysis and the antiapoptotic effect, implicating SphK1 as a critical regulator of these processes. Inhibition of glycolysis by 2-DG further increased apoptosis, confirming the protective role of glycolytic metabolism under SMG. These findings demonstrate that SMG enhances glycolysis and limits apoptosis in hDPSCs via SphK1 upregulation, suggesting that microgravity conditions may augment stem cell survival and function."

IO biomarker • Journal • ANXA5 • BAX • BCL2 • CASP3 • LDHA • PKM • SPHK1

Aberrant lipid metabolism reshapes the immune landscape in bone metastasis of nasopharyngeal carcinoma. (PubMed, J Immunother Cancer) - "The synergy between the SPHK1 inhibitor PF543 and anti-programmed cell death protein 1 therapy amplified treatment effectiveness beyond standalone approaches. Overall, the SPHK1/S1P pathway advances NPC growth and aids in suppressing immune defense. Regulation of lipid metabolism may be a therapeutic target against BM in NPC and may improve the effectiveness of immunotherapy."

Journal • Head and Neck Cancer • Infectious Disease • Metabolic Disorders • Nasopharyngeal Carcinoma • Oncology • Solid Tumor • CD8 • SPHK1

Compound Gardenia Radix Granule mitigates liver fibrosis in CCl4-induced mice by repressing SphK1-S1PR2 axis-mediated p-ERK signaling. (PubMed, Phytomedicine) - "CGRG ameliorates LF by inhibiting the SphK1-S1PR2-ERK pathway, offering new mechanistic insights and supporting its clinical application. These findings highlight the value of TCM polypharmacology in targeting redundant fibrogenic pathways."

Journal • Preclinical • Fibrosis • Immunology • Liver Cirrhosis • Metabolic Disorders • COL1A1 • IL1B • S1PR2 • SPHK1 • TGFB1 • TNFA

Autophagy-dependent secretion of ENO1 mediates chemoresistance of glioblastoma and tumor microenvironment remodeling. (PubMed, Cell Death Dis) - "In this study, we demonstrated that temozolomide (TMZ) could activate the autophagy-dependent secretory pathway to promote extracellular secretion of Alpha-enolase (ENO1)...Importantly, in vivo studies confirmed that combined therapy with the SPHK1 inhibitor PF-543, the TLR4 antagonist TAK-242, and TMZ synergistically suppressed tumor growth and significantly enhanced the efficacy of TMZ. Collectively, these findings reveal that ENO1 mediates intercellular crosstalk between GBM cells and M2-TAMs via autophagy-dependent secretion, thereby driving TMZ chemoresistance and functioning as an oncogene in GBM. Targeting the ENO1/TLR4 signaling axis reshapes the immune microenvironment and enhances the efficacy of TMZ, offering a promising therapeutic strategy and potential combinatorial targets for precision therapy in GBM."

Biomarker • IO biomarker • Journal • Brain Cancer • Glioblastoma • Oncology • Solid Tumor • ENO1 • SPHK1

SPHK1-mediated M2 macrophage polarization drives TGF-β1-dependent thrombus fibrosis. (PubMed, Front Immunol) - "This study demonstrates that SPHK1 promotes M2 macrophage polarization and drives TGF-β1-dependent thrombus fibrosis, underscoring its critical role in the progression of CTEPH. Pharmacological inhibition of SPHK1 by PF543 effectively attenuates fibrotic remodeling and suppresses M2 macrophage polarization, suggesting that SPHK1 may serve as a promising therapeutic target for the treatment of chronic thrombus-associated fibrosis."

Journal • Cardiovascular • Fibrosis • Hematological Disorders • Hypertension • Immunology • Pulmonary Arterial Hypertension • Pulmonary Disease • Pulmonary Embolism • Respiratory Diseases • Thrombosis • ARG1 • CD36 • CD68 • FASN • SCARB1 • SPHK1 • TGFB1

Mechanisms and potential therapeutic targets of SphK1 and SphK2 in hepatocellular carcinoma. (PubMed, Front Med (Lausanne)) - "It also maintains telomere activity via mitochondrial S1P, which promotes tumor survival and facilitates resistance to regorafenib. In targeted therapy, SphK1 inhibitors (e.g., PF-543) and SphK2 inhibitors (e.g., ABC294640) have shown significant anti-tumor effects in preclinical models...This paper systematically summarizes the mechanisms of action and therapeutic progress of SphK1/SphK2 in HCC. It provides an important theoretical basis for the clinical translation of precision therapy strategies in HCC."

Journal • Review • Hepatocellular Cancer • Oncology • Solid Tumor • SPHK1 • SPHK2

Structural dynamics of sphingosine kinase 1 regulation and inhibition. (PubMed, bioRxiv) - "We identify a previously uncharacterized catalytic intermediate with a distinct conformation and a highly dynamic lipid-binding loop 1 (LBL-1), sensitive to potent inhibitors such as PF-543...Our findings reveal a multilayered regulatory mechanism driven by structural flexibility and establish a novel inhibitory paradigm. This framework provides critical insight into SK1 regulation and a foundation for developing next-generation SK1-targeted therapeutics."

Journal • Oncology • SPHK1

A new insight into the mechanism of DEHP-induced cardiotoxicity: Triggering pyroptosis of cardiomyocytes by disrupting sphingolipid metabolism. (PubMed, J Hazard Mater) - "DEHP exposure also increased pyroptosis-related proteins, reversible via SPHK1 inhibitor PF543 or S1PR2 siRNA. In conclusion, this study first links DEHP-induced cardiac pyroptosis to SPHK1/S1PR2 signaling in mice, providing novel insights into DEHP-associated cardiotoxicity, contributing to cardiac damage and thereby offering new theoretical insights into DEHP-related cardiac toxicity."

Journal • Cardiovascular • Metabolic Disorders • CRP • S1PR2 • SPHK1

Investigate the potential inhibitors of sphingosine kinase 1 (SphK1) with molecular dynamics and artificial intelligence drug design methods. (PubMed, J Mol Model) - "Therefore, this study aims to investigate the interaction mechanism between Epidanshenspiroketallactone, PF-543, and SPHK1 in the J-type channel, and to design new small molecules using AI Drug Design (AIDD)...The MD simulation force field was selected as the AMBER99SB force field, the temperature was set at 310 K, and the total MD simulation time was 7.2 μs. A recurrent neural network-long short-term memory (RNN-LSTM) machine model was employed for the design of novel inhibitors."

Journal • SPHK1

Alisol A 24-acetate protects against NASH-associated fibrosis via suppression of Kupffer cell-derived SPHK1/S1P axis. (PubMed, Phytomedicine) - "AA exerts potent anti-steatotic, anti-inflammatory, and antifibrotic effects in experimental NASH, primarily by targeting the SPHK1/S1P signaling axis in Kupffer cells. This study is the first to identify AA as a direct modulator of KC-derived SPHK1 signaling, offering a novel strategy to disrupt KC-HSC crosstalk and mitigate liver fibrosis in NASH."

Journal • Fibrosis • Hepatocellular Cancer • Hepatology • Immunology • Liver Cirrhosis • Metabolic Dysfunction-Associated Steatohepatitis • Metabolic Dysfunction-Associated Steatotic Liver Disease • Oncology • Solid Tumor • IL1B • SPHK1 • TNFA

Hot on the TRAIL: Targeting SPHK1 in Colorectal Cancer: Therapeutic Potential of PF-543. (PubMed, Dig Dis Sci) - No abstract available

Journal • Colorectal Cancer • Oncology • Solid Tumor • SPHK1

High-throughput split-GFP antiviral screening assay against fusogenic paramyxoviruses. (PubMed, Antiviral Res) - "Two molecules were identified: Cathepsin Inhibitor 1 with henipavirus-specific activity and PF-543 with pan-paramyxovirus activity. Both molecules inhibit viral replication by blocking cell-cell fusion. The split-GFP assay presented here will enable the development of extensive drug discovery initiatives aimed at identifying much-needed pan-henipavirus/paramyxovirus inhibitors."

Journal • Infectious Disease • Measles • Mumps

Sphingolipid modulation and anti-tumor activity of Jaspine B in HepG2 bearing mice. (PubMed, Arch Pharm Res) - "The anti-cancer effect and reduced plasma S1P levels induced by Jaspine B were comparable to PF543, a selective SphK1 inhibitor, in HepG2-xenografted mice. In conclusion, this study provides in vitro and in vivo evidence that Jaspine B is a promising anti-cancer agent for hepatocellular carcinoma, acting through SphK1 inhibition, with favorable pharmacokinetic and tumor distribution properties. This study also suggested that reduced plasma S1P levels may serve as a therapeutic biomarker for SphK1 inhibitors in hepatocellular carcinoma treatment."

Journal • Preclinical • Hepatocellular Cancer • Oncology • Solid Tumor • SPHK1

FAM46C expression sensitizes multiple myeloma cells to PF-543-induced cytotoxicity (EACR 2025) - "Overall, our findings indicate that FAM46C plays a crucial role in drug response, enhancing sensitivity to PF-543 in both in vitro and in vivo settings. Our results reveal a novel synergistic interaction between FAM46C expression and SPHK1 inhibition, presenting a promising therapeutic approach for MM treatment."

Hematological Malignancies • Multiple Myeloma • Oncology • SPHK1 • SPHK2 • TENT5C