[HTML][HTML] Hypoxia-inducible factor (HIF)-1α suppression in myeloma cells blocks tumoral growth in vivo inhibiting angiogenesis and bone destruction

P Storti, M Bolzoni, G Donofrio, I Airoldi, D Guasco… - Leukemia, 2013 - nature.com
P Storti, M Bolzoni, G Donofrio, I Airoldi, D Guasco, D Toscani, E Martella, M Lazzaretti…
Leukemia, 2013nature.com
Abstract Hypoxia-inducible transcription factor-1 (HIF-1α) is overexpressed in multiple
myeloma (MM) cells within the hypoxic microenvironment. Herein, we explored the effect of
persistent HIF-1α inhibition by a lentivirus short hairpin RNA pool on MM cell growth either in
vitro or in vivo and on the transcriptional and pro-angiogenic profiles of MM cells. HIF-1α
suppression did not have a significant impact on MM cell proliferation and survival in vitro
although, increased the antiproliferative effect of lenalidomide. On the other hand, we found …
Abstract
Hypoxia-inducible transcription factor-1 (HIF-1α) is overexpressed in multiple myeloma (MM) cells within the hypoxic microenvironment. Herein, we explored the effect of persistent HIF-1α inhibition by a lentivirus short hairpin RNA pool on MM cell growth either in vitro or in vivo and on the transcriptional and pro-angiogenic profiles of MM cells. HIF-1α suppression did not have a significant impact on MM cell proliferation and survival in vitro although, increased the antiproliferative effect of lenalidomide. On the other hand, we found that HIF-1α inhibition in MM cells downregulates the pro-angiogenic genes VEGF, IL8, IL10, CCL2, CCL5 and MMP9. Pro-osteoclastogenic cytokines were also inhibited, such as IL-7 and CCL3/MIP-1α. The effect of HIF-1α inhibition was assessed in vivo in nonobese diabetic/severe combined immunodeficiency mice both in a subcutaneous and an intratibial MM model. HIF-1α inhibition caused a dramatic reduction in the weight and volume of the tumor burden in both mouse models. Moreover, a significant reduction of the number of vessels and vascular endothelial growth factors (VEGFs) immunostaining was observed. Finally, in the intratibial experiments, HIF-1α inhibition significantly blocked bone destruction. Overall, our data indicate that HIF-1α suppression in MM cells significantly blocks MM-induced angiogenesis and reduces MM tumor burden and bone destruction in vivo, supporting HIF-1α as a potential therapeutic target in MM.
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