Description

In multiple myeloma (MM), hypoxia-inducible transcription factor-1 (HIF-1) is overexpressed in the MM cells of the hypoxic bone marrow (BM) microenvironment. Herein, we explored in MM cells the in vitro and in vivo effects of persistent HIF-1 inhibition by expression of a lentivirus shRNA pool on proliferation, survival and transcriptional and pro-angiogenic profiles. Among the significantly modulated genes (326 and 361 genes in hypoxic and normoxic condition, respectively), we found that HIF-1 inhibition in the human myeloma cell line JJN3 downregulates the pro-angiogenic molecules VEGF, IL8, IL10, CCL2, CCL5, and MMP9. Interestingly, several pro-osteoclastogenic cytokines were also inhibited, such as IL-7 and CCL3/MIP-1. The effect of HIF-1 inhibition was assessed in vivo in NOD/SCID mice both in subcutaneous and intratibial models, indicating in either case a dramatic reduction of weight and volume of the tumor burden as a consequence of HIF-1 knockdown. Moreover, a significant reduction of the number of vessels per field and VEGF immunostaining were observed. Finally, in the intra-tibial experiments, HIF-1 inhibition significantly blocks JJN3-induced bone destruction. Overall, our data indicate that HIF-1 suppression in MM cells significantly blocks MM-induced angiogenesis and reduces both tumor burden and bone destruction in vivo, strongly indicating HIF-1 as an emerging therapeutic target in MM.

Publication Title

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

Sample Metadata Fields

Specimen part, Cell line