Novel Bifunctional Conjugates Targeting PD-L1/PARP7 as Dual Immunotherapy for Potential Cancer Treatment.

Bifunctional conjugates targeting PD-L1/PARP7 were designed, synthesized, and evaluated for the first time. Compounds B3 and C6 showed potent activity against PD-1/PD-L1 interaction (IC50 = 0.426 and 0.342 µM, respectively) and PARP7 (IC50 = 2.50 and 7.05 nM, respectively). They also displayed excellent binding affinity with hPD-L1, approximately 100-200-fold better than that of hPD-1. Both compounds restored T-cell function, leading to the increase of IFN-γ secretion. In the coculture assay, B3 and C6 enhanced the killing activity of MDA-MB-231 cells by Jurkat T cells in a concentration-dependent manner. Furthermore, B3 and C6 displayed significant in vivo antitumor efficacy in a melanoma B16-F10 tumor mouse model, more than 5.3-fold better than BMS-1 (a PD-L1 inhibitor) and RBN-2397 (a PARP7i clinical candidate) at the dose of 25 mg/kg, without observable side effects. These results provide valuable insight and understanding for developing bifunctional conjugates for potential anticancer therapy.

Discovery and bioassay of disubstituted ß-elemene-NO donor conjugates: synergistic enhancement in the treatment of leukemia.

Natural products are essential sources of antitumor drugs. One such molecule, ß-elemene, is a potent antitumor compound extracted from Curcuma wenyujin. In the present investigation, a series of novel 13,14-disubstituted nitric oxide (NO)-donor ß-elemene derivatives were designed, with ß-elemene as the foundational compound, and subsequently synthesized to evaluate their therapeutic potential against leukemia. Notably, the derivative labeled as compound 13d demonstrated a potent anti-proliferative activity against the K562 cell line, with a high NO release. In vivo studies indicated that compound 13d could effectively inhibit tumor growth, exhibiting no discernible toxic manifestations. Specifically, a significant tumor growth inhibition rate of 62.9% was observed in the K562 xenograft tumor mouse model. The accumulated data propound the potential therapeutic application of compound 13d in the management of leukemia.

Design, synthesis and anti-tumor efficacy evaluation of novel 1,3-diaryl propane-based polyphenols obtained from Claisen rearrangement reaction.

Polyphenols such as resveratrol, honokiol and nordihydroguaiaretic acid are widely existing in nature products or synthetic compounds with interesting biological activities. Inspired by their structural feature, a total of 49 1,3-diaryl propane-based polyphenols were designed and synthesized through Claisen rearrangement reaction. New compounds were initially assessed for their anti-proliferative activities against various cancer cell lines (PC-3, U87MG, U251, HCT116) at a concentration of 50 µM, and the results guided the SAR of this series of compounds. Further screening of selected compounds against seven cancer cell lines (three additional colon cancer cell lines namely COLO205, HT29 and SW480 were chosen) led to the identification of two advanced leads 2t and 3t with IC50 values ranging from 8.2 ± 0.1 to 19.3 ± 1.9 µM. Both compounds also showed promising anti-proliferative activities against COLO205 in dose- and time-dependent manners. Furthermore, 2t and 3t exhibited good anti-tumor efficacy in COLO205 xenografted mice model with TGI values ranging from 38% to 58%. These results warrant the further investigation of this series of compounds.

Design, Synthesis and Biological Evaluation of Histone Deacetylase Inhibitors Based on Pyrrolo[2,3-d]pyrimidine and Pyrrolo[2,3-b]pyridine Scaffolds.

Histone deacetylases (HDACs) are validated targets for the development of anticancer drugs in epigenetics. We have designed and synthesized a series of novel HDAC inhibitors based on pyrrolo[2,3-d]pyrimidine and pyrrolo[2,3-b]pyridine scaffolds. Compound B3 {(E)-3-(4-(((1-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)piperidin-4-yl)amino)methyl)phenyl)-N-hydroxyacrylamide} exhibits potent inhibitory activity against HDACs 1, 2, 3, 6, and 8 with IC50 values of 5.2, 6.0, 8.8, 4.4, and 173.0 nM, respectively. It exhibited potent antiproliferative effects against three tumour cell lines (IC50 values of 0.13, 0.37, and 1.11 µM, against MV-4-11, K562, and WSU-DLCL-2 cells, respectively) with two- to sixfold improvement relative to suberoylanilide hydroxamic acid (SAHA). Mechanistic studies on WSU-DLCL-2 cells revealed that B3 exhibits anticancer effects through the induction of G0 /G1 -phase arrest and promotion of apoptosis. The results of this study warrant further investigation of this compound series for the treatment of hematological malignancy.

Design, synthesis and biological evaluation of novel histone deacetylase (HDAC) inhibitors derived from ß-elemene scaffold.

ß-Elemene is the major active ingredient of TCM anticancer drug elemene extracts. To further improve its antitumor activity and poor solubility, a polar HDACi pharmacophore was incorporated its scaffold. Systematic SAR studies led to the discovery of compounds 27f and 39f, which exhibited potent inhibitory activity against HDACs (HDAC1: IC50 = 22 and 9 nM; HDAC6: 8 and 14 nM, respectively). In cellular levels, 27f and 39f significantly inhibited cell proliferation of five tumour cell lines (IC50: 0.79 - 4.42 µM). Preliminary mechanistic studies indicated that 27f and 39f efficiently induced cell apoptosis. Unexpectedly, compound 39f could also stimulate cell cycle arrest in G1 phase. Further in vivo study in WSU-DLCL-2 xenografted mouse model validated the antitumor activities of 27f, without significant toxicity. The results suggest the therapeutic potential of these HDACs inhibitors in lymphoma and provide valuable insight and understanding for further structural optimisation around ß-elemene scaffold.