title: A novel muscarinic antagonist R2HBJJ inhibits non-small cell lung cancer cell growth and arrests the cell cycle in G0/G1.
abstract: Lung cancers express the cholinergic autocrine loop, which facilitates the progression of cancer cells. The antagonists of mAChRs have been demonstrated to depress the growth of small cell lung cancers (SCLCs). In this study we intended to investigate the growth inhibitory effect of R2HBJJ, a novel muscarinic antagonist, on non-small cell lung cancer (NSCLC) cells and the possible mechanisms. The competitive binding assay revealed that R2HBJJ had a high affinity to M3 and M1 AChRs. R2HBJJ presented a strong anticholinergic activity on carbachol-induced contraction of guinea-pig trachea. R2HBJJ markedly suppressed the growth of NSCLC cells, such as H1299, H460 and H157. In H1299 cells, both R2HBJJ and its leading compound R2-PHC displayed significant anti-proliferative activity as M3 receptor antagonist darifenacin. Exogenous replenish of ACh could attenuate R2HBJJ-induced growth inhibition. Silencing M3 receptor or ChAT by specific-siRNAs resulted in a growth inhibition of 55.5% and 37.9% on H1299 cells 96 h post transfection, respectively. Further studies revealed that treatment with R2HBJJ arrested the cell cycle in G0/G1 by down-regulation of cyclin D1-CDK4/6-Rb. Therefore, the current study reveals that NSCLC cells express an autocrine and paracrine cholinergic system which stimulates the growth of NSCLC cells. R2HBJJ, as a novel mAChRs antagonist, can block the local cholinergic loop by antagonizing predominantly M3 receptors and inhibit NSCLC cell growth, which suggest that M3 receptor antagonist might be a potential chemotherapeutic regimen for NSCLC.
authors.affiliation: Beijing Institute of Pharmacology and Toxicology, Beijing, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Hua
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Wei
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Liu
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Ma
authors.forename: Xinhua
authors.initials: X
authors.lastname: He
authors.forename: Rengong
authors.initials: R
authors.lastname: Zhuo
authors.forename: Zhe
authors.initials: Z
authors.lastname: Zhao
authors.forename: Liyun
authors.initials: L
authors.lastname: Wang
authors.forename: Haitao
authors.initials: H
authors.lastname: Yan
authors.forename: Bohua
authors.initials: B
authors.lastname: Zhong
authors.forename: Jianquan
authors.initials: J
authors.lastname: Zheng
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use; D001592:Benzyl Alcohols / Q000494:pharmacology* / Q000627:therapeutic use; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000473:pathology*; D002453:Cell Cycle / Q000187:drug effects*; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D004353:Drug Evaluation, Preclinical; D005260:Female; D016193:G1 Phase / Q000187:drug effects; D006168:Guinea Pigs; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000473:pathology*; D008954:Models, Biological; D018727:Muscarinic Antagonists / Q000494:pharmacology* / Q000627:therapeutic use; D011812:Quinuclidines / Q000494:pharmacology* / Q000627:therapeutic use; D016192:Resting Phase, Cell Cycle / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D001592:Benzyl Alcohols; D018727:Muscarinic Antagonists; D011812:Quinuclidines; C582325:R2HBJJ compound