Growth factor independence 1 expression in myeloma cells enhances their growth, survival, and osteoclastogenesis

Daniela N. Petrusca, Denise Toscani, Feng Ming Wang, Cheolkyu Park, Colin D. Crean, Judith L. Anderson, Silvia Marino, Khalid S. Mohammad, Dan Zhou, Rebecca Silbermann, Quanhong Sun, Noriyoshi Kurihara, Deborah L. Galson, Nicola Giuliani, G. David Roodman

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


Background: In spite of major advances in treatment, multiple myeloma (MM) is currently an incurable malignancy due to the emergence of drug-resistant clones. We previously showed that MM cells upregulate the transcriptional repressor, growth factor independence 1 (Gfi1), in bone marrow stromal cells (BMSCs) that induces prolonged inhibition of osteoblast differentiation. However, the role of Gfi1 in MM cells is unknown. Methods: Human primary CD138+ and BMSC were purified from normal donors and MM patients' bone marrow aspirates. Gfi1 knockdown and overexpressing cells were generated by lentiviral-mediated shRNA. Proliferation/apoptosis studies were done by flow cytometry, and protein levels were determined by Western blot and/or immunohistochemistry. An experimental MM mouse model was generated to investigate the effects of MM cells overexpressing Gfi1 on tumor burden and osteolysis in vivo. Results: We found that Gfi1 expression is increased in patient's MM cells and MM cell lines and was further increased by co-culture with BMSC, IL-6, and sphingosine-1-phosphate. Modulation of Gfi1 in MM cells had major effects on their survival and growth. Knockdown of Gfi1 induced apoptosis in p53-wt, p53-mutant, and p53-deficient MM cells, while Gfi1 overexpression enhanced MM cell growth and protected MM cells from bortezomib-induced cell death. Gfi1 enhanced cell survival of p53-wt MM cells by binding to p53, thereby blocking binding to the promoters of the pro-apoptotic BAX and NOXA genes. Further, Gfi1-p53 binding could be blocked by HDAC inhibitors. Importantly, inoculation of MM cells overexpressing Gfi1 in mice induced increased bone destruction, increased osteoclast number and size, and enhanced tumor growth. Conclusions: These results support that Gfi1 plays a key role in MM tumor growth, survival, and bone destruction and contributes to bortezomib resistance, suggesting that Gfi1 may be a novel therapeutic target for MM.

Original languageEnglish (US)
Article number123
JournalJournal of Hematology and Oncology
Issue number1
StatePublished - Oct 4 2018
Externally publishedYes


  • Apoptosis and osteolysis
  • Bone disease
  • Gfi1
  • Multiple myeloma
  • p53

ASJC Scopus subject areas

  • Molecular Biology
  • Hematology
  • Oncology
  • Cancer Research


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