Ewing's sarcoma of bone tumor cells produces MCSF that stimulates monocyte proliferation in a novel mouse model of Ewing's sarcoma of bone

Treating bone metastases with local therapy in a breast cancer patient resulted in decreased pain and prevented fracture

Lytic lesions from bone metastases from breast, lung and prostate carcinomas, are associated with a poor prognosis and significant morbidities that include fracture and debilitating pain. Chemotherapeutics, palliative radiation therapy and surgical intervention are routinely used to treat these lesions. The ZetaMet™ Bone Graft is a novel antitumorigenic and osteoinductive graft that offers a potential alternative treatment option. ZetaMet is composed of calcium phosphate salts, type-I collagen and the small molecule N-allyl noroxymorphone dihydrate. Here, we report the case of a stage IV breast cancer patient with multiple lytic metastatic lesions to the spine that were successfully treated, which led to a significant reduction in pain and increased quality of life. This outcome demonstrates that a locally administered therapeutic intervention may represent an important alternative for patients with bone metastases that warrants further study.

Identification of Factors Driving Doxorubicin-Resistant Ewing Tumor Cells to Survival

BACKGROUND

Ewing sarcoma (ES) cells exhibit extreme plasticity that contributes to the cell's survival and recurrence. Although multiple studies reveal various signaling pathways mediated by the EWSR1/FLI1 fusion, the specific transcriptional control of tumor cell resistance to doxorubicin is unknown. Understanding the molecular hubs that contribute to this behavior provides a new perspective on valuable therapeutic options against tumor cells.

METHODS

Single-cell RNA sequencing and LC-MS/MS-based quantitative proteomics were used.

RESULTS

A goal of this study was to identify protein hubs that would help elucidate tumor resistance which prompted ES to relapse or metastasize. Several differentially expressed genes and proteins, including adhesion, cytoskeletal, and signaling molecules, were observed between embryonic fibroblasts and control and doxorubicin-treated tumor cell lines. While several cancer-associated genes/proteins exhibited similar expression across fibroblasts and non-treated cells, upregulation of some proteins belonging to metabolic, stress response, and growth pathway activation was uniquely observed in doxorubicin-treated sarcoma cells, respectively. The novel information on differentially expressed genes/proteins provides insights into the biology of ES cells, which could help elucidate mechanisms of their recurrence.

CONCLUSIONS

Collectively, our results identify a novel role of cellular proteins in contributing to tumor cell resistance and escape from doxorubicin therapy and contributing to ES progression.