title: Suppression of ABCG2 inhibits cancer cell proliferation.
abstract: The ATP-binding cassette efflux transporter, ABCG2, is widely expressed in a variety of normal tissues, stem cells, as well as cancer cells. Existing data suggest that ABCG2 plays an important role in the maintenance of the stem cell phenotype and multidrug resistance of cancer cells. However, the potential role of ABCG2 in other cellular processes remains speculative and poorly understood. Here, we demonstrated that ABCG2 is involved in the proliferation of cancer cells. We used RNA interference approach to efficiently and specifically down-regulate ABCG2 protein levels in MCF-7/MX and A549 cells. We showed that knockdown of ABCG2 significantly inhibited the proliferation of these cells. Suppression of ABCG2 reduced the percentage of cells in the S phase of the cell cycle and enhanced G0/G1 accumulation. The G0/G1 growth arrest was associated with down-regulation of cyclin D3 and up-regulation of p21. Furthermore, blocking of ABCG2 function by chemical inhibitor fumitremorgin C also inhibited cell proliferation via the prolonged G0/G1 interval. Taken together, these findings suggest that ABCG2 correlates with cell cycle progression, highlighting a novel function of ABCG2 in cancer cell proliferation.
authors.affiliation: State Key Laboratory of Experimental Hematology, Institute of Hematology & Hospital of Blood Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, People's Republic of China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Chen
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
authors.forename: Qian
authors.initials: Q
authors.lastname: Ren
authors.forename: Qinjun
authors.initials: Q
authors.lastname: Zhao
authors.forename: Hongying
authors.initials: H
authors.lastname: Ren
authors.forename: Shihong
authors.initials: S
authors.lastname: Lu
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Zhongchao
authors.initials: Z
authors.lastname: Han
mesh_terms: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000378:metabolism; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics*; D001973:Bromodeoxyuridine / Q000378:metabolism; D002453:Cell Cycle / Q000235:genetics; D002455:Cell Division / Q000235:genetics; D017931:DNA Primers; D018432:Drug Resistance, Multiple / Q000235:genetics; D005260:Female; D020868:Gene Silencing; D006801:Humans; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D016196:S Phase
chemical_list: C116614:ABCG2 protein, human; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D017931:DNA Primers; D009363:Neoplasm Proteins; D034741:RNA, Small Interfering; D001973:Bromodeoxyuridine