DNA is the prime target of anticancer treatments. DNA damage triggers a series of signaling cascades promoting cellular survival, including DNA repair, cell cycle arrest, and autophagy. The elevated basal and/or stressful levels of both DNA repair and autophagy observed in tumor cells, in contrast to normal cells, have been identified as the most important drug-responsive programs that impact the outcome of anticancer therapy. The exact relationship between DNA repair and autophagy in cancer cells remains unclear. On one hand, autophagy has been shown to regulate some of the DNA repair proteins after DNA damage by maintaining the balance between their synthesis, stabilization, and degradation. One the other hand, some evidence has demonstrated that some DNA repair molecular have a crucial role in the initiation of autophagy. In this review, we mainly discuss the interplay between DNA repair and autophagy in anticancer therapy and expect to enlighten some effective strategies for cancer treatment.
Dodecaphenyltetracene (4), the largest perphenylacene yet prepared, was synthesized from knownt etraphenylfuran, hexaphenylisobenzofuran, and 1,2,4,5-tetrabromo-3,6diphenylbenzene in three steps.The X-ray structure of the deep red, highly luminescent 4 shows it to be aD 2 -symmetric molecule with an end-to-end twist of 978 8.T he central acene is encapsulated by the peripheral phenyl substituents,a nd as aresult, the molecule is relatively unreactive and even displays reversible electrochemical oxidation and reduction.
GPR84 is a proinflammatory G protein-coupled
receptor associated
with several inflammatory and fibrotic diseases. GPR84 antagonists
have been evaluated in clinical trials to treat ulcerative colitis,
idiopathic pulmonary fibrosis, and nonalcoholic steatohepatitis. However,
the variety of potent and selective GPR84 antagonists is still limited.
Through high-throughput screening, a novel phosphodiester compound
hit 1 was identified as a GPR84 antagonist. The subsequent
structural optimization led to the identification of compound 33 with improved potency in the calcium mobilization assay
and the ability to inhibit the chemotaxis of neutrophils and macrophages
upon GPR84 activation. In a DSS-induced mouse model of ulcerative
colitis, compound 33 significantly alleviated colitis
symptoms and reduced the disease activity index score at oral doses
of 25 mg/kg qd, with an efficacy similar to that of positive control
5-aminosalicylic acid (200 mg/kg, qd, po), suggesting that compound 33 is a promising candidate for further drug development.
PROteolysis Targeting Chimeras (PROTACs) are bifunctional molecules that degrade target proteins through recruiting E3 ligases. However, their application is limited in part because few E3 ligases can be recruited by known E3 ligase ligands. Through competitive activity-based protein profiling, we found that piperlongumine (PL), a natural product, binds multiple E3 ligases. To evaluate whether PL can be used as an E3 ligase ligand, we generated a series of PL and SNS-032 (a selective CDK9 inhibitor) conjugates and found that the lead conjugate 955 can potently degrade CDK9 in a ubiquitin-proteasome dependent manner. In addition, 955 is more potent than SNS-032 against various tumor cells in vitro. Through TurboID-based proteomics and mechanistic studies, we identified KEAP1 as the E3 ligase recruited by PL to degrade CDK9. These findings demonstrate that PL is a novel E3 ligase ligand that can be used to generate potent anticancer PROTACs.
Condensation of 1,8,13-tris(mercaptomethyl)triptycene and tris(bromomethyl)methane yields an in,in-cyclophane with two inwardly directed methine groups. Based on X-ray analysis and DFT and MP2 calculations, the hydrogen-hydrogen non-bonded contact distance is estimated to be 1.50-1.53 Å. Furthermore, the two in-hydrogen atoms show obvious spin-spin coupling with J=2.0 Hz.
A γ-carbon activation method that operates through N-heterocyclic carbene/Brønsted acid cooperative catalysis for highly enantioselective synthesis of δ-lactams is reported. The protocol allows the challenging remote γ-carbon control of regioselectivity and enantioselectivity through introduction of an appropriate γ-leaving group in the enals. The reaction offers good yields and excellent enantioselectivities, and the resulting cyclic products can be easily converted into high-value drug-like derivatives.
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