title: Small molecule RL71 targets SERCA2 at a novel site in the treatment of human colorectal cancer.
abstract: While targeted agents are an important part of the treatment arsenal for colorectal cancer, there is still a lack of efficient small-molecule targeted agents based on the understanding of pathogenic molecular mechanisms. In this study, curcumin analog RL71 displayed potent cytotoxicity towards human colon cancer cells with an IC50 of 0.8 µM in SW480 cells and inhibited xenotransplanted tumor growth in a dose-dependent manner. Using affinity chromatography, we identified sarco/endoplasmic reticulum calcium-ATPase (SERCA) 2 as the binding target of RL71. Most notably, RL71 demonstrated special binding to SERCA2 at a novel site with the lowest estimated free energy -8.89 kcal mol(-1), and the SERCA2 residues critical for RL71 binding were identified. RL71 suppressed the Ca(2+)-ATPase activity of SERCA2 both in vitro and in vivo, accompanied by the induction of endoplasmic reticulum stress leading to apoptosis and G2/M cycle arrest in SW480 cells. In addition, RL71 showed synergistic cytotoxicity with the pan-SERCA inhibitor thapsigargin. These results suggest that RL71 could be a selective small-molecule inhibitor of SERCA2, and that it may serve as a lead compound for the study of targeted colorectal cancer therapy.
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China.
authors.forename: Baofang
authors.initials: B
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China.
authors.forename: Minxia
authors.initials: M
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China.
authors.forename: Jiahuang
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Fan
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Xiang
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China.
authors.forename: Xingqi
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China.
authors.forename: Xiaoning
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China.
authors.forename: Xudong
authors.initials: X
authors.lastname: Wu
authors.affiliation: Bioorganic and Medicinal Chemistry Research Center, School of Pharmaceutical Sciences, Wenzhou Medical College, Wenzhou, China.
authors.forename: Guang
authors.initials: G
authors.lastname: Liang
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Shen
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xu
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D003474:Curcumin / Q000031:analogs & derivatives* / Q000494:pharmacology; D036381:Diarylheptanoids; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D007124:Immunoenzyme Techniques; D051379:Mice; D008819:Mice, Nude; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays
chemical_list: C577607:3,5-bis(3,4,5-trimethoxybenzylidene)-1-methylpiperidine-4-one; D000970:Antineoplastic Agents; D036381:Diarylheptanoids; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; C506946:ATP2A2 protein, human; D003474:Curcumin; D002118:Calcium
keywords: RL71; SERCA2; colorectal cancer; novel binding site; targeted agent