Withaferin A inhibits in vivo growth of breast cancer cells accelerated by Notch2 knockdown.
The present study offers novel insights into the molecular circuitry of accelerated in vivo tumor growth by Notch2 knockdown in triple-negative breast cancer (TNBC) cells. Therapeutic vulnerability of Notch2-altered growth to a small molecule (withaferin A, WA) is also demonstrated. MDA-MB-231 and SUM159 cells were used for the xenograft studies. A variety of technologies were deployed to elucidate the mechanisms underlying tumor growth augmentation by Notch2 knockdown and its reversal by WA, including Fluorescence Molecular Tomography for measurement of tumor angiogenesis in live mice, Seahorse Flux analyzer for ex vivo measurement of tumor metabolism, proteomics, and Luminex-based cytokine profiling. Stable knockdown of Notch2 resulted in accelerated in vivo tumor growth in both cells reflected by tumor volume and/or latency. For example, the wet tumor weight from mice bearing Notch2 knockdown MDA-MB-231 cells was about 7.1-fold higher compared with control (P < 0.0001). Accelerated tumor growth by Notch2 knockdown was highly sensitive to inhibition by a promising steroidal lactone (WA) derived from a medicinal plant. Molecular underpinnings for tumor growth intensification by Notch2 knockdown included compensatory increase in Notch1 activation, increased cellular proliferation and/or angiogenesis, and increased plasma or tumor levels of growth stimulatory cytokines. WA administration reversed many of these effects providing explanation for its remarkable anti-cancer efficacy. Notch2 functions as a tumor growth suppressor in TNBC and WA offers a novel therapeutic strategy for restoring this function.
Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Su-Hyeong
SH
Kim
Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Eun-Ryeong
ER
Hahm
2.32A Hillman Cancer Center Research Pavilion, University of Pittsburgh Cancer Institute, 5117 Centre Avenue, Pittsburgh, PA, 15213, USA.
Julie A
JA
Arlotti
Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Suman K
SK
Samanta
Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Michelle B
MB
Moura
2.32A Hillman Cancer Center Research Pavilion, University of Pittsburgh Cancer Institute, 5117 Centre Avenue, Pittsburgh, PA, 15213, USA.|Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Stephen H
SH
Thorne
2.32A Hillman Cancer Center Research Pavilion, University of Pittsburgh Cancer Institute, 5117 Centre Avenue, Pittsburgh, PA, 15213, USA.|Department of Biostatistics, University of Pittsburgh, Pittsburgh, PA, USA.
Yongli
Y
Shuai
2.32A Hillman Cancer Center Research Pavilion, University of Pittsburgh Cancer Institute, 5117 Centre Avenue, Pittsburgh, PA, 15213, USA.|Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Carolyn J
CJ
Anderson
2.32A Hillman Cancer Center Research Pavilion, University of Pittsburgh Cancer Institute, 5117 Centre Avenue, Pittsburgh, PA, 15213, USA.|Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Alexander G
AG
White
2.32A Hillman Cancer Center Research Pavilion, University of Pittsburgh Cancer Institute, 5117 Centre Avenue, Pittsburgh, PA, 15213, USA.|Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Anna
A
Lokshin
Department of Food and Nutrition, Chosun University, Gwangju, Korea.
Joomin
J
Lee
Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA. singhs@upmc.edu.|2.32A Hillman Cancer Center Research Pavilion, University of Pittsburgh Cancer Institute, 5117 Centre Avenue, Pittsburgh, PA, 15213, USA. singhs@upmc.edu.
Shivendra V
SV
Singh
D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage* / Q000494:pharmacology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D016207:Cytokines / Q000378:metabolism; D015536:Down-Regulation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D055785:Gene Knockdown Techniques; D006801:Humans; D051379:Mice; D051881:Receptor, Notch1 / Q000378:metabolism; D051883:Receptor, Notch2 / Q000235:genetics*; D064726:Triple Negative Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000378:metabolism; D054358:Withanolides / Q000008:administration & dosage* / Q000494:pharmacology; D023041:Xenograft Model Antitumor Assays
D000972:Antineoplastic Agents, Phytogenic; D016207:Cytokines; C497762:Notch1 protein, mouse; C497765:Notch2 protein, mouse; D051881:Receptor, Notch1; D051883:Receptor, Notch2; D054358:Withanolides; C009684:withaferin A
Breast cancer; Chemoprevention; Cytokines; Notch2; Withaferin A