Combination of methylselenocysteine with tamoxifen inhibits MCF-7 breast cancer xenografts in nude mice through elevated apoptosis and reduced angiogenesis

  • Zengshan Li
  • Latonya Carrier
  • Aditi Belame
  • Arunthavarani Thiyagarajah
  • Virgilio A. Salvo
  • Matthew E. Burow
  • Brian G. RowanEmail author
Preclinical Study


To investigate the therapeutic effect of methylselenocysteine (MSC) combined with tamoxifen in MCF-7 breast cancer xenograft and the underlying mechanisms. MCF-7 breast cancer xenograft was established in ovariectomized female athymic nude mice and treated with tamoxifen and/or MSC. Tumor size was measured twice a week. Immunohistochemistry and TUNEL assays were used to measure ERα expression, ERα target genes (progesterone receptor (PR) and cyclin D1 expression), Ki-67 index, apoptosis and microvessel density. Combined treatment with tamoxifen and MSC synergistically inhibited tumor growth compared to MSC alone and tamoxifen alone. MSC alone or MSC + tamoxifen significantly reduced ERα, PR and cyclin D1, Ki67 index and microvessel density while increasing apoptosis in tumor tissues. These findings demonstrate synergistic growth inhibition of ERα positive breast cancer xenografts by combination of tamoxifen with organic selenium compounds. Organic selenium may provide added benefit when combined with tamoxifen in adjuvant therapy or prevention.


Breast cancer Xenograft Synergy Selenium Tamoxifen Apoptosis Proliferation Angiogenesis 





Estrogen receptor α


Progesterone receptor




Microvessel density




Androgen receptor


Prostate specific antigen


Poly ADP-ribose polymerase


Terminal DNA transferase-mediated dUTP nick end labeling



This project was supported, in part, by grants from the Louisiana Cancer Research Consortium to BGR.


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Copyright information

© Springer Science+Business Media, LLC. 2008

Authors and Affiliations

  • Zengshan Li
    • 1
    • 2
  • Latonya Carrier
    • 1
  • Aditi Belame
    • 1
  • Arunthavarani Thiyagarajah
    • 3
  • Virgilio A. Salvo
    • 4
  • Matthew E. Burow
    • 4
  • Brian G. Rowan
    • 1
    Email author
  1. 1.Department of Structural & Cellular BiologyTulane University School of MedicineNew OrleansUSA
  2. 2.State Key Laboratory of Cancer Biology, Department of Pathology, XiJing HospitalFourth Military Medical UniversityXi’anPeople’s Republic of China
  3. 3.Department of Environmental Health Sciences, School of Public Health and Tropical MedicineTulane University Health Science CenterNew OrleansUSA
  4. 4.Section of Hematology & Medical Oncology, Department of MedicineTulane University School of MedicineNew OrleansUSA

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