title: MiRNA-Embedded ShRNAs for Radiation-Inducible LGMN Knockdown and the Antitumor Effects on Breast Cancer.
abstract: Legumain (LGMN) is highly expressed in breast cancer (BC) and other solid tumors and is a potential anticancer target. Here we investigate the anti-tumor effects of short hairpin RNAs (shRNAs) targeting LGMN embedded in a microRNA-155 (miR-155) architecture, which is driven by a radiation-inducible chimeric RNA polymerase II (Pol II) promoter. Lentiviral vectors were generated with the chimeric promoter which controlled the expression of downstream shRNA-miR-155 cassette. Fluorescence was observed by using confocal microscopy. Real-time quantitative PCR and Western blotting were used to determine the expression level of LGMN, MMP2, and MMP9. Furthermore, the proliferation and invasive ability of BC cells was analyzed via plate colony formation and invasion assays. Here we demonstrated that the chimeric promoter could be effectively induced by radiation treatment. Furthermore, the shRNA-miR-155 cassette targeting LGMN could be effectively activated by the chimeric promoter. Radiation plus knockdown of LGMN impairs colony formation and dampens cell migration and invasion in BC cells. Inhibition of LGMN downregulates MMP2 and MMP9 expression in BC cells. Pol II-driven shRNA-miR-155 could effectively suppress the growth and invasiveness of BC cells, and that the interference effects could be regulated by radiation doses. Moreover, knockdown of LGMN alleviates the aggressive phenotype of BC cells through modulating MMPs expression.
authors.affiliation: Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, 400014, China.|Key Laboratory of Pediatrics in Chongqing, Chongqing, 400014, China.|Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, 400014, China.|Department of Critical Care Medicine, Children's Hospital of Chongqing Medical University, Chongqing, 400014, China.
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Zhang
authors.affiliation: Department of Radiation Oncology, Sichuan Cancer Hospital, Chengdu, 610041, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Cao
authors.affiliation: Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, College of Preventive Medicine, Third Military Medical University, Chongqing, 400038, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Liu
authors.affiliation: Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, College of Preventive Medicine, Third Military Medical University, Chongqing, 400038, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Li
authors.affiliation: Department of Radiation Oncology, Sichuan Cancer Hospital, Chengdu, 610041, China.
authors.forename: Wei-Dong
authors.initials: WD
authors.lastname: Wang
authors.affiliation: Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, 400014, China.|Key Laboratory of Pediatrics in Chongqing, Chongqing, 400014, China.|Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, 400014, China.|Department of Critical Care Medicine, Children's Hospital of Chongqing Medical University, Chongqing, 400014, China.
authors.forename: Xing-Yong
authors.initials: XY
authors.lastname: Wang