title: Increased chemosensitivity and radiosensitivity of human breast cancer cell lines treated with novel functionalized single-walled carbon nanotubes.
abstract: Hypoxia is a major cause of treatment resistance in breast cancer. Single-walled carbon nanotubes (SWCNTs) exhibit unique properties that make them promising candidates for breast cancer treatment. In the present study, a new functionalized single-walled carbon nanotube carrying oxygen was synthesized; it was determined whether this material could increase chemosensitivity and radiosensitivity of human breast cancer cell lines, and the underlying mechanisms were investigated. MDA-MB-231 cells growing in folic acid (FA) free medium, MDA-MB-231 cells growing in medium containing FA and ZR-75-1 cells were treated with chemotherapy drugs or radiotherapy with or without tombarthite-modified-FA-chitosan (R-O2-FA-CHI)-SWCNTs under hypoxic conditions, and the cell viability was determined by water-soluble tetrazolium salts-1 assay. The cell surviving fractions were determined by colony forming assay. Cell apoptosis induction was monitored by flow cytometry. Expression of B-cell lymphoma 2 (Bcl-2), survivin, hypoxia-inducible factor 1-α (HIF-1α), multidrug resistance-associated protein 1 (MRP-1), P-glycoprotein (P-gp), RAD51 and Ku80 was monitored by western blotting. The novel synthesized R-O2-FA-CHI-SWCNTs were able to significantly enhance the chemosensitivity and radiosensitivity of human breast cancer cell lines and the material exhibited its expected function by downregulating the expression of Bcl-2, survivin, HIF-1α, P-gp, MRP-1, RAD51 and Ku80.
authors.affiliation: Department of General Surgery, XinHua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, P.R. China.
authors.forename: Yijun
authors.initials: Y
authors.lastname: Jia
authors.affiliation: Department of General Surgery, Shanghai International Medical Center, Shanghai 201318, P.R. China.
authors.forename: Ziyi
authors.initials: Z
authors.lastname: Weng
authors.affiliation: School of Mechanical and Power Engineering, Shanghai Jiaotong University, Shanghai 200240, P.R. China.
authors.forename: Chuanying
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Pathology, XinHua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, P.R. China.
authors.forename: Mingjie
authors.initials: M
authors.lastname: Zhu
authors.affiliation: Department of General Surgery, XinHua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, P.R. China.
authors.forename: Yunshu
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Department of General Surgery, XinHua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, P.R. China.
authors.forename: Longlong
authors.initials: L
authors.lastname: Ding
authors.affiliation: Department of Breast and Thyroid Surgery, Liaocheng People's Hospital, Liaocheng, Shandong 252000, P.R. China.
authors.forename: Yongkun
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Mechanical and Power Engineering, Shanghai Jiaotong University, Shanghai 200240, P.R. China.
authors.forename: Xianhua
authors.initials: X
authors.lastname: Cheng
authors.affiliation: Department of Radiology, Tenth People's Hospital, Shanghai Tongji University School of Medicine, Shanghai 200072, P.R. China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Lin
authors.affiliation: Department of General Surgery, XinHua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, P.R. China; Department of Breast Surgery, Shanghai Gynecology Hospital of Fudan University, Shanghai 200011, P.R. China.
authors.forename: Kejin
authors.initials: K
authors.lastname: Wu
keywords: breast cancer; chemotherapy sensitivity; hypoxia; radiotherapy sensitivity; single-walled carbon nanotubes