No abstract

Our study highlights the overactivated neddylation pathway in lung cancer development and as a promising therapeutic target.

Purpose: Targeting the protein neddylation pathway has become an attractive anticancer strategy; however, the role of death receptor-mediated extrinsic apoptosis during treatment remained to be determined.Experimental Design: The activation of extrinsic apoptosis and its role in MLN4924 treatment of human esophageal squamous cell carcinoma (ESCC) were evaluated both in vitro and in vivo. The expression of the components of extrinsic apoptotic pathway was determined by immunoblotting analysis and downregulated by siRNA silencing for mechanistic studies.Results: Pharmaceutical or genetic inactivation of neddylation pathway induced death receptor 5 (DR5)-mediated apoptosis and led to the suppression of ESCC in murine models. Mechanistically, neddylation inhibition stabilized activating transcription factor 4 (ATF4), a Cullin-Ring E3 ubiquitin ligases (CRL) substrate. Transcription factor CHOP was subsequently transactivated by ATF4 and further induced the expression of DR5 to activate caspase-8 and induce extrinsic apoptosis. Moreover, the entire neddylation pathway was hyperactivated in ESCC and was negatively associated with patient overall survival.Conclusions: Our findings highlight a critical role of ATF4-CHOP-DR5 axis-mediated extrinsic apoptosis in neddylationtargeted cancer therapy and support the clinical investigation of neddylation inhibitors (e.g., MLN4924) for the treatment of ESCC, a currently treatment-resistant disease with neddylation hyperactivation.

Various heteroaryl and bicyclo-aliphatic analogues of zwitterionic biaryl P2Y 14 receptor (P2Y 14 R) antagonists were synthesized, and affinity was measured in P2Y 14 R-expressing Chinese hamster ovary cells by flow cytometry. Given this series' low water solubility, various polyethylene glycol derivatives of the distally binding piperidin-4-yl moiety of moderate affinity were synthesized. Rotation of previously identified 1,2,3-triazole attached to the central m-benzoic acid core (25) provided moderate affinity but not indole and benzimidazole substitution of the aryl-triazole. The corresponding P2Y 14 R region is predicted by homology modeling as a deep, sterically limited hydrophobic pocket, with the outward pointing piperidine moiety being the most flexible. Bicyclic-substituted piperidine ring derivatives of naphthalene antagonist 1, e.g., quinuclidine 17 (MRS4608, IC 50 ≈ 20 nM at hP2Y 14 R/mP2Y 14 R), or of triazole 2, preserved affinity. Potent antagonists 1, 7a, 17, and 23 (10 mg/kg) protected in an ovalbumin/Aspergillus mouse asthma model, and PEG conjugate 12 reduced chronic pain. Thus, we expanded P2Y 14 R antagonist structure−activity relationship, introducing diverse physical−chemical properties.