title: Plumbagin attenuates cancer cell growth and osteoclast formation in the bone microenvironment of mice.
abstract: OBJECTIVE
  To investigate the effects of plumbagin, a naphthoquinone derived from the medicinal plant Plumbago zeylanica, on human breast cancer cell growth and the cancer cell-induced osteolysis in the bone microenvironment of mice.
  
  
  METHODS
  Human breast cancer cell subline MDA-MB-231SA with the ability to spread and grow in the bone was tested. The cell proliferation was determined using the CCK-8 assay. Apoptosis was detected with Annexin V/PI double-labeled flow cytometry. Red fluorescent protein-labeled MDA-MB-231SArfp cells were injected into the right tibia of female BALB/c-nu/nu mice. Three days after the inoculation, the mice were injected with plumbagin (2, 4, or 6 mg/kg, ip) 5 times per week for 7 weeks. The growth of the tumor cells was monitored using an in vivo imaging system. After the mice were sacrificed, the hind limbs were removed for radiographic and histological analyses.
  
  
  RESULTS
  Plumbagin (2.5-20 μmol/L) concentration-dependently inhibited the cell viability and induced apoptosis of MDA-MB-231SA cells in vitro (the IC50 value of inhibition of cell viability was 14.7 μmol/L). Administration of plumbagin to breast cancer bearing mice delayed the tumor growth by 2-3 weeks and reduced the tumor volume by 44%-74%. The in vivo imaging study showed that plumbagin dose-dependently inhibited MDA-MB-231SArfp cell growth in bone microenvironment. Furthermore, X-ray images and micro-CT study demonstrated that plumbagin reduced bone erosion area and prevented a decrease in bone tissue volume. Histological studies showed that plumbagin dose-dependently inhibited the breast cancer cell growth, enhanced the cell apoptosis and reduced the number of TRAcP-positive osteoclasts.
  
  
  CONCLUSIONS
  Plumbagin inhibits the cell growth and induces apoptosis in human breast cancer cells in mice bone microenvironment, leading to significant reduction in osteolytic lesions caused by the tumor cells.
authors.affiliation: 1] Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedic Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China [2] Wendeng Zhenggu Hospital of Shandong Province, Wendeng 264400, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yan
authors.affiliation: Department of Pharmacy, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.
authors.forename: Ting-yu
authors.initials: TY
authors.lastname: Wang
authors.affiliation: Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedic Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.
authors.forename: Qi-ming
authors.initials: QM
authors.lastname: Fan
authors.affiliation: Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedic Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Du
authors.affiliation: School of Pathology and Laboratory Medicine, University of Western Australia, Nedlands, 6009, Western Australia, Australia.
authors.forename: Jia-ke
authors.initials: JK
authors.lastname: Xu
authors.affiliation: Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedic Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.
authors.forename: Zan-jing
authors.initials: ZJ
authors.lastname: Zhai
authors.affiliation: Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedic Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.
authors.forename: Hao-wei
authors.initials: HW
authors.lastname: Li
authors.affiliation: Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedic Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.
authors.forename: Ting-ting
authors.initials: TT
authors.lastname: Tang
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology / Q000627:therapeutic use*; D001859:Bone Neoplasms / Q000473:pathology / Q000517:prevention & control* / Q000556:secondary; D001943:Breast Neoplasms / Q000473:pathology / Q000517:prevention & control*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009285:Naphthoquinones / Q000494:pharmacology / Q000627:therapeutic use*; D010010:Osteoclasts / Q000187:drug effects* / Q000473:pathology; D059016:Tumor Microenvironment / Q000187:drug effects* / Q000502:physiology
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D009285:Naphthoquinones; C014758:plumbagin