HSV1716 Prevents Myeloma Cell Regrowth When Combined with Bortezomib In Vitro and Significantly Reduces Systemic Tumor Growth in Mouse Models.

Multiple myeloma remains largely incurable due to refractory disease; therefore, novel treatment strategies that are safe and well-tolerated are required. Here, we studied the modified herpes simplex virus HSV1716 (SEPREHVIR®), which only replicates in transformed cells. Myeloma cell lines and primary patient cells were infected with HSV1716 and assessed for cell death using propidium iodide (PI) and Annexin-V staining and markers of apoptosis and autophagy by qPCR. Myeloma cell death was associated with dual PI and Annexin-V positivity and increased expression of apoptotic genes, including CASP1, CASP8, CASP9, BAX, BID, and FASL. The combination of HSV1716 and bortezomib treatments prevented myeloma cell regrowth for up to 25 days compared to only transient cell growth suppression with bortezomib treatment. The viral efficacy was tested in a xenograft (JJN-3 cells in NSG mice) and syngeneic (murine 5TGM1 cells in C57BL/KaLwRijHsd mice) systemic models of myeloma. After 6 or 7 days, the post-tumor implantation mice were treated intravenously with the vehicle or HSV1716 (1 × 107 plaque forming units/1 or 2 times per week). Both murine models treated with HSV1716 had significantly lower tumor burden rates compared to the controls. In conclusion, HSV1716 has potent anti-myeloma effects and may represent a novel therapy for multiple myeloma.

Orphan GPR116 mediates the insulin sensitizing effects of the hepatokine FNDC4 in adipose tissue.

The proper functional interaction between different tissues represents a key component in systemic metabolic control. Indeed, disruption of endocrine inter-tissue communication is a hallmark of severe metabolic dysfunction in obesity and diabetes. Here, we show that the FNDC4-GPR116, liver-white adipose tissue endocrine axis controls glucose homeostasis. We found that the liver primarily controlled the circulating levels of soluble FNDC4 (sFNDC4) and lowering of the hepatokine FNDC4 led to prediabetes in mice. Further, we identified the orphan adhesion GPCR GPR116 as a receptor of sFNDC4 in the white adipose tissue. Upon direct and high affinity binding of sFNDC4 to GPR116, sFNDC4 promoted insulin signaling and insulin-mediated glucose uptake in white adipocytes. Indeed, supplementation with FcsFNDC4 in prediabetic mice improved glucose tolerance and inflammatory markers in a white-adipocyte selective and GPR116-dependent manner. Of note, the sFNDC4-GPR116, liver-adipose tissue axis was dampened in (pre) diabetic human patients. Thus our findings will now allow for harnessing this endocrine circuit for alternative therapeutic strategies in obesity-related pre-diabetes.