Divergent synthesis and elaboration of structure activity relationship for quinoline derivatives as highly selective NTPDase inhibitor

Ectonucleotidase inhibitors: targeting signaling pathways for therapeutic advancement-an in-depth review

Ectonucleotidase inhibitors are a family of pharmacological drugs that, by selectively targeting ectonucleotidases, are essential in altering purinergic signaling pathways. The hydrolysis of extracellular nucleotides and nucleosides is carried out by these enzymes, which include ectonucleoside triphosphate diphosphohydrolases (NTPDases) and ecto-5'-nucleotidase (CD73). Ectonucleotidase inhibitors can prevent the conversion of ATP and ADP into adenosine by blocking these enzymes and reduce extracellular adenosine. These molecules are essential for purinergic signaling, which is associated with a variability of physiological and pathological processes. By modifying extracellular nucleotide metabolism and improving purinergic signaling regulation, ectonucleotide pyrophosphatase/phosphodiesterase (ENPP) inhibitors have the potential to improve cancer treatment, inflammatory management, and immune response modulation. Purinergic signaling is affected by CD73 inhibitors because they prevent AMP from being converted to adenosine. These inhibitors are useful in cancer therapy and immunotherapy because they may improve chemotherapy effectiveness and alter immune responses. Purinergic signaling is controlled by NTPDase inhibitors, which specifically target enzymes involved in extracellular nucleotide breakdown. These inhibitors show promise in reducing immunological responses, thrombosis, and inflammation, perhaps assisting in the treatment of cardiovascular and autoimmune illnesses. Alkaline phosphatase (ALP) inhibitors alter the function of enzymes involved in dephosphorylation reactions, which has an impact on a variety of biological processes. By altering the body's phosphate levels, these inhibitors may be used to treat diseases including hyperphosphatemia and certain bone problems. This article provides a guide for researchers and clinicians looking to leverage the remedial capability of ectonucleotidase inhibitors in a variety of illness scenarios by illuminating their processes, advantages, and difficulties.

Synthesis and biological evaluation of sulfamoyl benzamide derivatives as selective inhibitors for h-NTPDases

The aim of this research work is the synthesis of sulfamoyl-benzamides as a selective inhibitor for h-NTPDases. Sulfonamides are synthesized in aqueous medium from chlorosulfonylbenzoic acid while carboxamides are synthesized using carbodiimide coupling decorated with different biologically relevant substituents such as n-butyl, cyclopropyl, benzylamine, morpholine, and substituted anilines. In addition, sulfonamide-carboxamide derivatives were synthesized having the same substituents on either side. These compounds were screened against h-NTPDase activity, a main family of ectonucleotidases. Among the eight discovered isoforms of the h-NTPDases, four isoforms, h-NTPDase1, -2, -3, and -8, are involved in various physiological and pathological functions, for instance thrombosis, diabetes, inflammation, and cancer. The compound N-(4-bromophenyl)-4-chloro-3-(morpholine-4-carbonyl)benzenesulfonamide (3i) was found to be the most potent inhibitor of h-NTPDase1 with an IC₅₀ value of 2.88 ± 0.13 μM. Similarly, the compounds N-(4-methoxyphenyl)-3-(morpholinosulfonyl)benzamide (3f), 5-(N-benzylsulfamoyl)-2-chloro-N-(4-methoxyphenyl)benzamide (3j) and 2-chloro-N-cyclopropyl-5-(N-cyclopropylsulfamoyl)benzamide (4d) reduced the activity of the h-NTPDases2 with IC₅₀ in sub-micromolar concentrations. Against the h-NTPDase3, 3i was the potent compound with an IC₅₀ concentration of 0.72 ± 0.11 μM. The h-NTPDase8 was selectively blocked by the most potent inhibitor 2-chloro-5-(N-cyclopropylsulfamoyl)benzoic acid (2d) with (IC₅₀ = 0.28 ± 0.07 μM). Moreover, the molecular docking studies of the potent inhibitors showed significant interactions with the amino acids of the respective h-NTPDase homology model proteins.

ATP and Adenosine Metabolism in Cancer: Exploitation for Therapeutic Gain

Adenosine is an evolutionary ancient metabolic regulator linking energy state to physiologic processes, including immunomodulation and cell proliferation. Tumors create an adenosine-rich immunosuppressive microenvironment through the increased release of ATP from dying and stressed cells and its ectoenzymatic conversion into adenosine. Therefore, the adenosine pathway becomes an important therapeutic target to improve the effectiveness of immune therapies. Prior research has focused largely on the two major ectonucleotidases, ectonucleoside triphosphate diphosphohydrolase 1/cluster of differentiation (CD)39 and ecto-5'-nucleotidase/CD73, which catalyze the breakdown of extracellular ATP into adenosine, and on the subsequent activation of different subtypes of adenosine receptors with mixed findings of antitumor and protumor effects. New findings, needed for more effective therapeutic approaches, require consideration of redundant pathways controlling intratumoral adenosine levels, including the alternative NAD-inactivating pathway through the CD38-ectonucleotide pyrophosphatase phosphodiesterase (ENPP)1-CD73 axis, the counteracting ATP-regenerating ectoenzymatic pathway, and cellular adenosine uptake and its phosphorylation by adenosine kinase. This review provides a holistic view of extracellular and intracellular adenosine metabolism as an integrated complex network and summarizes recent data on the underlying mechanisms through which adenosine and its precursors ATP and ADP control cancer immunosurveillance, tumor angiogenesis, lymphangiogenesis, cancer-associated thrombosis, blood flow, and tumor perfusion. Special attention is given to differences and commonalities in the purinome of different cancers, heterogeneity of the tumor microenvironment, subcellular compartmentalization of the adenosine system, and novel roles of purine-converting enzymes as targets for cancer therapy. SIGNIFICANCE STATEMENT: The discovery of the role of adenosine as immune checkpoint regulator in cancer has led to the development of novel therapeutic strategies targeting extracellular adenosine metabolism and signaling in multiple clinical trials and preclinical models. Here we identify major gaps in knowledge that need to be filled to improve the therapeutic gain from agents targeting key components of the adenosine metabolic network and, on this basis, provide a holistic view of the cancer purinome as a complex and integrated network.

E-NTPDases: Possible Roles on Host-Parasite Interactions and Therapeutic Opportunities

Belonging to the GDA1/CD39 protein superfamily, nucleoside triphosphate diphosphohydrolases (NTPDases) catalyze the hydrolysis of ATP and ADP to the monophosphate form (AMP) and inorganic phosphate (Pi). Several NTPDase isoforms have been described in different cells, from pathogenic organisms to animals and plants. Biochemical characterization of nucleotidases/NTPDases has revealed the existence of isoforms with different specificities regarding divalent cations (such as calcium and magnesium) and substrates. In mammals, NTPDases have been implicated in the regulation of thrombosis and inflammation. In parasites, such as Trichomonas vaginalis, Trypanosoma spp., Leishmania spp., Schistosoma spp. and Toxoplasma gondii, NTPDases were found on the surface of the cell, and important processes like growth, infectivity, and virulence seem to depend on their activity. For instance, experimental evidence has indicated that parasite NTPDases can regulate the levels of ATP and Adenosine (Ado) of the host cell, leading to the modulation of the host immune response. In this work, we provide a comprehensive review showing the involvement of the nucleotidases/NTPDases in parasites infectivity and virulence, and how inhibition of NTPDases contributes to parasite clearance and the development of new antiparasitic drugs.