Evaluation of F8-TNF-α in Models of Early and Progressive Metastatic Osteosarcoma

Abstract

The targeted delivery of tumor necrosis factor-α (TNF-α) with antibodies specific to splice isoforms of fibronectin [e.g., F8-TNF, specific to the extra-domain A (EDA) domain of fibronectin] has already shown efficacy against experimental sarcomas but has not yet been investigated in orthotopic sarcomas. Here, we investigated F8-TNF in a syngeneic K7 M2–derived orthotopic model of osteosarcoma as a treatment against pulmonary metastases, the most frequent cause of osteosarcoma-related death. Immunofluorescence on human osteosarcoma tissue confirmed the presence of EDA in primary tumors (PTs) as well as metastases. In mice, the efficacy of F8-TNF against PTs and early pulmonary metastases was evaluated. Intratibial PT growth was not affected by F8-TNF, yet early micrometastases were reduced possibly due to an F8-TNF–dependent attraction of pulmonary CD4+, CD8+, and natural killer cells. Furthermore, immunofluorescence revealed stronger expression of EDA in early pulmonary metastases compared with PT tissue. To study progressing pulmonary metastases, a hind limb amputation model was established, and the efficacy of F8-TNF, alone or combined with doxorubicin, was investigated. Despite the presence of EDA in metastases, no inhibition of progressive metastatic growth was detected. No significant differences in numbers of CD4+ or CD8+ cells or F4/80+ and Ly6G+ myeloid-derived cells were observed, although a strong association between metastatic growth and presence of pulmonary Ly6G+ myeloid-derived cells was detected. In summary, these findings demonstrate the potential of F8-TNF in activating the immune system and reducing early metastatic growth yet suggest a lack of efficacy of F8-TNF alone or combined with doxorubicin against progressing osteosarcoma metastases.

Alternative splicing of leptin receptor overlapping transcript in osteosarcoma

“…57 Not surprisingly, upregulation of IL-6 and TNF-α has been observed in human OS cells. 58,59 In addition, IL-6 mediates tumor-host interactions that facilitate lung colonization of metastasis-initiating by OS cells. 60,61 Consequently, LEPROT may be implicated in OS initiation and metastasis through upregulating expression of IL-6 and TNF-α .…”

Osteosarcoma-Derived Extracellular Vesicles Induce Lung Fibroblast Reprogramming

“…A medium-sized, hollow-fiber culture cartridge with a 20 kDa molecular weight cut-off (C2011, Fibercell Systems; Frederick, MD, USA) was pre-cultured according to the manufacturer’s instructions. 143-B cells stably expressing mCherry, luciferase and LacZ [ 41 , 42 ] were expanded in conventional culture flasks and 10 8 cells were used to inoculate the hollow-fiber culture cartridge. Cells were then slowly adapted to bioreactor culture conditions over two weeks by gradually increasing the concentration of protein-free medium (1:1 DMEM/Ham’s F12 + 10% Fibercell Systems chemically defined medium for high density cell culture (CDM-HD; Fibercell Systems, Frederick, MD, USA) protein-free supplement + 100 U/mL penicillin/streptomycin).…”

TYROBP, TLR4 and ITGAM regulated macrophages polarization and immune checkpoints expression in osteosarcoma

“…The introduced effective therapy has improved in recent years; however, the 5-year survival rates of OS remains low 19 , 20 . Therefore, searching for effective novel therapies is of utmost importance.…”