3-Acetyloxy-2-cyano-2-(alkylaminocarbamoyl)propyl Groups as Biodegradable Protecting Groups of Nucleoside 5 '-mono-Phosphates

Thymidine 5`-bis[3-acetyloxy-2-cyano-2-(2-phenylethylcarbamoyl)propyl] phosphate (1) has been prepared and the removal of phosphate protecting groups by hog liver carboxyesterase (HLE) at pH 7.5 and 37 degrees C has been followed by HPLC. The first detectable intermediates are the (R(P))- and (S(P))-diastereomers of the monodeacetylated triester 14, which subsequently undergo concurrent retro-aldol condensation to diester 4 and enzyme-catalyzed hydrolysis to the fully deacetylated triester 15. The former pathway predominates, representing 90% of the overall breakdown of 14. The diester 4 undergoes the enzymatic deacetylation 700 times less readily than the triester, but gives finally thymidine 5`-monophosphate as the desired main product. To elucidate the potential toxicity of the electrophilic 2-cyano-N-(2-phenylethyl) acrylamideby-product 17 released upon the deprotection, the hydrolysis of 1 has also been studied in the presence of glutathione (GSH)

Acetylated and Methylated beta-Cyclodextrins as Viable Soluble Supports for the Synthesis of Short 2 '-Oligodeoxyribo-nucleotides in Solution

Novel soluble supports for oligonucleotide synthesis 11a-c have been prepared by immobilizing a 5'-O-protected 3'-O-(hex-5-ynoyl) thymidine (6 or 7) to peracetylated or permethylated 6-deoxy-6-azido-beta-cyclodextrins 10a or 10b by Cu(I)-promoted 1,3-dipolar cycloaddition. The applicability of the supports to oligonucleotide synthesis by the phosphoramidite strategy has been demonstrated by assembling a 3'-TTT-5' trimer from commercially available 5'-O-(4,4'-dimethoxytrityl) thymidine 3'-phosphoramidite. To simplify the coupling cycle, the 5'-O-(4,4'-dimethoxytrityl) protecting group has been replaced with an acetal that upon acidolytic removal yields volatile products. For this purpose, 5'-O-(1-methoxy-1-methylethyl)-protected 3'-(2-cyanoethyl-N, N-diisopropyl-phosphoramidite) s of thymidine (5a), N-4-benzoyl-2'-deoxycytidine (5b) and N-6-benzoyl-2'-deoxyadenosine (5c) have been synthesized and utilized in synthesis of a pentameric oligonucleotide 3'-TTCAT-5' on the permethylated cyclodextrin support 11c

Synthesis of Biotinylated Multipodal Glycoclusters on a Solid Support

Trivalent glycoconjugates, each bearing a biotin side arm in addition to three different sugar ligands, have been synthesized on a solid support. The conjugates were assembled on an orthogonally protected pentaerythrityl tetramine core that was anchored to the support through a backbone amide linker. Peptide coupling chemistry was applied to elongate three of the branches with beta-alanine and a fully acylated glycosylacetic acid. The fourth branch was levulinoylated and oximated with aminooxy-derivatized D-biotin, followed by acidolytic release into solution. The acyl protecting groups were removed by methoxide-catalyzed transesterification in methanol

Synthesis of 3',5'-Cyclic Phosphate and Thiophosphate Esters of 2'-C-Methyl Ribonucleosides

2'-C-Methylnucleosides are known to exhibit antiviral activity against Hepatitis C virus. Since the inhibitory activity depends on their intracellular conversion to 5'-triphosphates, dosing as appropriately protected 5'-phosphates or 5'-phosphorothioates appears attractive. For this purpose, four potential pro-drugs of 2'-C-methylguanosine, i.e., 3',5'-cyclic phosphorothioate of 2'-C-methylguanosine and 2'-C,O6-dimethylguanosine, 1 and 2, respectively, the S-[(pivaloyloxy)methyl] ester of 2'-C,O6-dimethylguanosine 3',5'-cyclic phosphorothioate and the O-methyl ester of 2'-C,O6-dimethylguanosine 3',5'-cyclic phosphate, 3 and 4, respectively, have been prepared

5 ',5 '-Phosphodiesters and esterase labile triesters of 2 '-C-methylribonucleosides

Bis(2'-C-methyladenosin-5'-yl) (11), bis(2'-C-methylguanosin-5'-yl) (13), bis(2'-C-methyluridin-5'-yl) (15) and 2'-C-methylguanosin-5'-yl 2'-C-methyluridin-5'-yl (16) phosphodiesters have been prepared as pro-drug candidates for the respective 2'-C-methylribonucleoside 5'-monophosphates, expectedly exhibiting antiviral activity against Hepatitis C virus. Additionally, the bis(2'-C-methyladenosine) diester has been converted to 3-acetyloxymethoxy-2,2-bis(ethoxycarbonyl)propyl (19) or pivaloyloxymethyl (20) triester. The underlying idea is that the 5',5'-phosphodiester is first released by intracellular carboxyesterases and subsequently cleaved to nucleoside and nucleoside 5'-monophosphate by phosphodiesterases

Systemic Blockade of Clever-1 Elicits Lymphocyte Activation Alongside Checkpoint Molecule Downregulation in Patients with Solid Tumors : Results from a Phase I/II Clinical Trial

Purpose: Macrophages are critical in driving an immunosuppressive tumor microenvironment that counteracts the efficacy of T-cell-targeting therapies. Thus, agents able to reprogram macrophages toward a proinflammatory state hold promise as novel immunotherapies for solid cancers. Inhibition of the macrophage scavenger receptor Clever-1 has shown benefit in inducing CD8 T-cell-mediated antitumor responses in mouse models of cancer, which supports the clinical development of Clever-1-targeting antibodies for cancer treatment. Patients and Methods: In this study, we analyzed the mode of action of a humanized IgG4 anti-Clever-1 antibody, FP-1305 (bexmarilimab), both in vitro and in patients with heavily pretreated metastatic cancer (n = 30) participating in part 1 (dose-finding) of a phase I/II open-label trial (NCT03733990). We studied the Clever-1 interactome in primary human macrophages in antibody pull-down assays and utilized mass cytometry, RNA sequencing, and cytokine profiling to evaluate FP-1305-induced systemic immune activation in patients with cancer. Results: Our pull-down assays and functional studies indicated that FP-1305 impaired multiprotein vacuolar ATPase-mediated endosomal acidification and improved the ability of macrophages to activate CD8(+)T-cells. In patients with cancer, FP-1305 administration led to suppression of nuclear lipid signaling pathways and a proinflammatory phenotypic switch in blood monocytes. These effects were accompanied by a significant increase and activation of peripheral T-cells with indications of antitumor responses in some patients. Conclusions: Our results reveal a nonredundant role played by the receptor Clever-1 in suppressing adaptive immune cells in humans. We provide evidence that targeting macrophage scavenging activity can promote an immune switch, potentially leading to intratumoral proinflammatory responses in patients with metastatic cancer.Peer reviewe

Stabilization of ribozyme-like cis-noncoding rRNAs induces apoptotic and nonapoptotic death in lung cells

Bidirectional non-protein-coding RNAs are ubiquitously transcribed from the genome. Convergent sense and antisense transcripts may regulate each other. Here, we examined the convergent cis-noncoding rRNAs (nc-rRNAs) in A5 and E9 lung cancer models. Sense nc-rRNAs extending from rDNA intergenic region to internal transcribed spacer of around 10 kb in length were identified. nc-rRNAs in sense direction exhibited in vitro characteristics of ribozymes, namely, degradation upon incubation with MgCl2 and stabilization by complementary oligonucleotides. Detection of endogenous cleavage-ligation products carrying internal deletion of hundreds to thousands nucleotides by massively parallel sequencing confirmed the catalytic properties. Transfection of oligonucleotides pairing with antisense nc-rRNAs stabilized both target and complementary transcripts, perturbed rRNA biogenesis, and induced massive cell death via apoptotic and/or nonapoptotic mechanisms depending on cell type and treatment. Oligonucleotides targeting cellular sense transcripts are less responsive. Spontaneously detached cells, though rare, also showed accumulation of nc-rRNAs and perturbation of rRNA biogenesis. Direct participation of nc-rRNAs in apoptotic and nonapoptotic death was demonstrated by transfection of synthetic nc-rRNAs encompassing the rDNA promoter. In sum, convergent cis-nc-rRNAs follow a feed-forward mechanism to regulate each other and rRNA biogenesis. This opens an opportunity to disrupt rRNA biogenesis, commonly upregulated in cancers, via inhibition of ribozyme-like activities in nc-rRNAs

Responsiveness and minimal clinically important difference for pain and disability instruments in low back pain patients

BACKGROUND: The choice of an evaluative instrument has been hampered by the lack of head-to-head comparisons of responsiveness and the minimal clinically important difference (MCID) in subpopulations of low back pain (LBP). The objective of this study was to concurrently compare responsiveness and MCID for commonly used pain scales and functional instruments in four subpopulations of LBP patients. METHODS: The Danish versions of the Oswestry Disability Index (ODI), the 23-item Roland Morris Disability Questionnaire (RMQ), the physical function and bodily pain subscales of the SF36, the Low Back Pain Rating Scale (LBPRS) and a numerical rating scale for pain (0–10) were completed by 191 patients from the primary and secondary sectors of the Danish health care system. Clinical change was estimated using a 7-point transition question and a numeric rating scale for importance. Responsiveness was operationalised using standardardised response mean (SRM), area under the receiver operating characteristic curve (ROC), and cut-point analysis. Subpopulation analyses were carried out on primary and secondary sector patients with LBP only or leg pain +/- LBP. RESULTS: RMQ was the most responsive instrument in primary and secondary sector patients with LBP only (SRM = 0.5–1.4; ROC = 0.75–0.94) whereas ODI and RMQ showed almost similar responsiveness in primary and secondary sector patients with leg pain (ODI: SRM = 0.4–0.9; ROC = 0.76–0.89; RMQ: SRM = 0.3–0.9; ROC = 0.72–0.88). In improved patients, the RMQ was more responsive in primary and secondary sector patients and LBP only patients (SRM = 1.3–1.7) while the RMQ and ODI were equally responsive in leg pain patients (SRM = 1.3 and 1.2 respectively). All pain measures demonstrated almost equal responsiveness. The MCID increased with increasing baseline score in primary sector and LBP only patients but was only marginally affected by patient entry point and pain location. The MCID of the percentage change score remained constant for the ODI (51%) and RMQ (38%) specifically and differed in the subpopulations. CONCLUSION: RMQ is suitable for measuring change in LBP only patients and both ODI and RMQ are suitable for leg pain patients irrespectively of patient entry point. The MCID is baseline score dependent but only in certain subpopulations. Relative change measured using the ODI and RMQ was not affected by baseline score when patients quantified an important improvement