title: AU-1 from Agavaceae plants causes transient increase in p21/Cip1 expression in renal adenocarcinoma ACHN cells in an miR-34-dependent manner.
abstract: Here, we show that AU-1, spirostanol saponin isolated from Agavaceae plants, causes a transient increase in cyclin-dependent kinase inhibitor (CDKI) p21/Cip1 through the upregulation of miRNAs, miR-34 and miR-21. AU-1 stimulated p21/Cip1 expression without exerting cytotoxicity against different types of carcinoma cell lines. In renal adenocarcinoma ACHN cells, AU-1 transiently elevated the expression level of p21/Cip1 protein without marked increases in p21/Cip1 mRNA levels. Rapid and transient increases in miR-34 and miR-21, both of which are known to upregulate p21/Cip1, were observed in AU-1-treated cells. Inhibitor for miR-34 and for miR-21 significantly blocked the AU-1-caused increase in p21/Cip1, indicating that elevation of p21/Cip1 protein by AU-1 is dependent on these microRNAs. We further clarified that NAD-dependent deacetylase SIRT1, a direct target of miR-34, is decreased by the treatment with AU-1. Furthermore, we found that SIRT1-knockdown increases p21/Cip1 protein levels in an miR-21-dependent manner. On the other hand, ectopic expression of p21/Cip1 resulted in the lowered expression of miR-34 and miR-21, suggesting that reciprocal regulation exists between p21/Cip1 and these miRNAs. We propose that the following feedback network composed of miR-34/SIRT1/miR-21/p21 is triggered by the treatment with AU-1: in cells treated with AU-1, transient elevation of miR-34 leads to the downregulation of SIRT1, thereby miR-21 is freed from SIRT1-dependent suppression. Then, elevated miR-21 upregulates p21/Cip1 protein, followed by the suppression of miR-34 expression.
authors.affiliation: Department of Hygiene and Health Sciences, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Horinouchi 1432-1, Hachiōji, Tokyo, 192-0392, Japan. tfujino@ps.toyaku.ac.jp.
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Fujino
authors.affiliation: Department of Medicinal Pharmacognosy, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Horinouchi 1432-1, Hachiōji, Tokyo, 192-0392, Japan.
authors.forename: Akihito
authors.initials: A
authors.lastname: Yokosuka
authors.affiliation: Department of Hygiene and Health Sciences, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Horinouchi 1432-1, Hachiōji, Tokyo, 192-0392, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Higurashi
authors.affiliation: Department of Hygiene and Health Sciences, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Horinouchi 1432-1, Hachiōji, Tokyo, 192-0392, Japan.
authors.forename: Rina
authors.initials: R
authors.lastname: Yokokawa
authors.affiliation: Department of Hygiene and Health Sciences, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Horinouchi 1432-1, Hachiōji, Tokyo, 192-0392, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Sakurai
authors.affiliation: Department of Hygiene and Health Sciences, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Horinouchi 1432-1, Hachiōji, Tokyo, 192-0392, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Harashima
authors.affiliation: Department of Environmental Health, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Horinouchi 1432-1, Hachiōji, Tokyo, 192-0392, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Miki
authors.affiliation: Department of Environmental Health, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Horinouchi 1432-1, Hachiōji, Tokyo, 192-0392, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Fujiwara
authors.affiliation: Department of Medicinal Pharmacognosy, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Horinouchi 1432-1, Hachiōji, Tokyo, 192-0392, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Mimaki
authors.affiliation: Department of Hygiene and Health Sciences, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Horinouchi 1432-1, Hachiōji, Tokyo, 192-0392, Japan.
authors.forename: Makio
authors.initials: M
authors.lastname: Hayakawa
mesh_terms: D000667:Ampicillin / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000070357:Asparagaceae / Q000737:chemistry*; D002292:Carcinoma, Renal Cell; D045744:Cell Line, Tumor; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism*; D018844:Cyclin-Dependent Kinases; D015536:Down-Regulation; D056945:Hep G2 Cells; D006801:Humans; D012333:RNA, Messenger / Q000096:biosynthesis
chemical_list: D050759:Cyclin-Dependent Kinase Inhibitor p21; C107055:N-(6,7-difluoroquinolonyl)ampicillin; D012333:RNA, Messenger; D000667:Ampicillin; D018844:Cyclin-Dependent Kinases
keywords: Agave utahensis; SIRT1; miR-21; miR-34; p21/Cip1