CD73 is a crucial regulator of adenosine production in the tumor microenvironment and, therefore, represents a valuable target for cancer immunotherapy. While different inhibitors of CD73 have been studied, the progress remains hindered by a lack of high-throughput assays that would allow the screening of large chemical libraries. Establishing a sensitive assay for the detection of CD73 activity could enable additions to the CD73 inhibitor chemical space as well as help facilitate a better understanding of the CD73 reaction mechanism. In this study, we focused on the development and adaptation of DIANA for CD73 high-throughput screening and showed that we can detect enzyme inhibition with high sensitivity. We then used this assay to screen an IOCB library, a proprietary set of chemical compounds with a special focus on nucleotide analogues. We identified several scaffolds that inhibit CD73 and in an SAR study demonstrated fine-tuning of the inhibition properties of monophosphonate analogues. Moreover, using a breast cancer cell line as a model with endogenous CD73 expression, we demonstrated the inhibition of CD73 directly on cells. The establishment of a sensitive assay for the detection of CD73 activity allowed us to develop potent inhibitors of the enzyme with low nanomolar inhibition constants. Our findings further promote the importance of CD73 inhibitors in cancer therapy.

• Klíčová slova
• CD73, DNA-linked probe, ecto-5′-nucleotidase, high-throughput screening, monophosphonate, tumor microenvironment,
• Publikační typ
• časopisecké články MeSH

7-Deazapurine (pyrrolo[2,3-d]pyrimidine) nucleosides are important analogues of biogenic purine nucleosides with diverse biological activities. Replacement of the N7 atom with a carbon atom makes the five-membered ring more electron rich and brings a possibility of attaching additional substituents at the C7 position. This often leads to derivatives with increased base-pairing in DNA or RNA or better binding to enzymes. Several types of 7-deazapurine nucleosides with potent cytostatic or cytotoxic effects have been identified. The most promising are 7-hetaryl-7-deazaadenosines, which are activated in cancer cells by phosphorylation and get incorporated both to RNA (causing inhibition of proteosynthesis) and to DNA (causing DNA damage). Mechanism of action of other types of cytostatic nucleosides, 6-hetaryl-7-deazapurine and thieno-fused deazapurine ribonucleosides, is not yet known. Many 7-deazaadenosine derivatives are potent inhibitors of adenosine kinases. Many types of sugar-modified derivatives of 7-deazapurine nucleosides are also strong antivirals. Most important are 2'-C-methylribo- or 2'-C-methyl-2'-fluororibonucleosides with anti-HCV activities (several compounds underwent clinical trials). Some underexplored areas of potential interest are also outlined.

• Klíčová slova
• antivirals, cytostatics, deazapurines, nucleosides, nucleotides,
• MeSH
• antivirové látky chemická syntéza   chemie   farmakologie   MeSH
• buňky A549 MeSH
• buňky Hep G2 MeSH
• HeLa buňky MeSH
• lidé MeSH
• nukleosidy chemická syntéza   chemie   farmakologie   MeSH
• protinádorové látky chemická syntéza   chemie   farmakologie   MeSH
• puriny chemie   MeSH
• racionální návrh léčiv MeSH
• screeningové testy protinádorových léčiv MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• 7-deazapurine MeSH Prohlížeč
• antivirové látky MeSH
• nukleosidy MeSH
• protinádorové látky MeSH
• puriny MeSH

Three types of sugar modified pyrimido[4,5-b]indole nucleosides (2'-deoxy-2'-fluororibo-, 2'-deoxy-2'-fluoroarabino- and arabinonucleosides) were synthesized by glycosylation of 4,6-dichloropyrimido[4,5-b]indole followed by modification of sugar moiety and introduction of substituents into position 4 by cross-coupling reactions or nucleophilic substitutions. Some 2'-fluororibo- and 2'-fluoroarabinonucleosides displayed interesting anti-HCV activities (IC50 = 1.6-20 μM) and the latter compounds also some anti-dengue activities (IC50 = 10.8-40 μM).

• Publikační typ
• časopisecké články MeSH