Oncostatin M Receptor as a Therapeutic Target for Radioimmune Therapy in Synovial Sarcoma.

Synovial sarcoma (SS) is a pediatric muscle cancer that primarily affects adolescents and young adults and has few treatment options. Complicating the treatment of synovial sarcoma is the low mutational burden of SS. Inflammatory pathways have been identified as being upregulated in some SS, leading to the discovery of upregulated oncostatin M receptor (OSMR). It was found that OSMR is upregulated in SS by RNAseq analysis and quantitative PCR, highlighting its potential in the treatment of SS. Also, OSMR is upregulated in mouse models for synovial sarcoma as demonstrated by western blot and immunohistochemistry, and the protein is present in both primary and metastatic sites of disease. Using a radioimmune therapy drug model, targeted therapy was synthesized for use in OSMR expressing SS and it was demonstrated that this drug is stable, while capable of efficient OSMR binding and isotope capture. Finally, this antibody conjugate exhibited ideal pharmacokinetics and targeted sites of disease in our mouse model and was taken up in both primary and metastatic diseased tissue. This suggests OSMR as an ideal target for therapy and this radioimmune therapy provides a novel treatment option for a disease with few therapy choices.

Tissue Engineering Through 3D Bioprinting to Recreate and Study Bone Disease.

The applications of 3D bioprinting are becoming more commonplace. Since the advent of tissue engineering, bone has received much attention for the ability to engineer normal bone for tissue engraftment or replacement. While there are still debates on what materials comprise the most durable and natural replacement of normal tissue, little attention is given to recreating diseased states within the bone. With a better understanding of the cellular pathophysiology associated with the more common bone diseases, these diseases can be scaled down to a more throughput way to test therapies that can reverse the cellular pathophysiology. In this review, we will discuss the potential of 3D bioprinting of bone tissue in the following disease states: osteoporosis, Paget's disease, heterotopic ossification, osteosarcoma, osteogenesis imperfecta, and rickets disease. The development of these 3D bioprinted models will allow for the advancement of novel therapy testing resulting in possible relief to these chronic diseases.

Epigenetic Changes at the Birc5 Promoter Induced by YM155 in Synovial Sarcoma.

YM155 is an anti-cancer therapy that has advanced into 11 different human clinical trials to treat various cancers. This apoptosis-inducing therapy indirectly affects the protein levels of survivin (gene: Birc5), but the molecular underpinnings of the mechanism remain largely unknown. Synovial sarcoma is a rare soft-tissue malignancy with high protein expression of survivin. We investigated whether YM155 would be a viable therapeutic option to treat synovial sarcoma. YM155 therapy was applied to human synovial sarcoma cell lines and to a genetically engineered mouse model of synovial sarcoma. We discovered that YM155 exhibited nanomolar potency against human synovial sarcoma cell lines and the treated mice with synovial sarcoma demonstrated a 50% reduction in tumor volume compared to control treated mice. We further investigated the mechanism of action of YM155 by looking at the change of lysine modifications of the histone tails that were within 250 base pairs of the Birc5 promoter. Using chromatin immunoprecipitation (ChIP)-qPCR, we discovered that the histone epigenetic marks of H3K27 for the Birc5 promoter changed upon YM155 treatment. H3K27me3 and H3K27ac increased, but the net result was decreased Birc5/survivin expression. Furthermore, the combination of molecular events resulted in caspase 3/7/8 upregulation and death of the sarcoma cells.

Quantifying Fluorescently Labeled Ceramide Levels in Human Sarcoma Cell Lines in Response to a Sphingomyelin Synthase Inhibitor.

Sphingolipid metabolism is an important process in sustaining the growth needs of rapidly dividing cancer cells. Enzymes that synthesize sphingolipids have become attractive targets in cancer pharmacology. Ceramide is a precursor for synthesizing sphingolipids such as sphingomyelin, sphingosine-1-phosphate, and glucosylceramide. Sphingomyelin synthase (SMS) is the enzyme that transfers a phosphatidylcholine to ceramide to generate sphingomyelin. To test the inhibition of SMS, scientists assess the buildup of ceramide in the cell, which is cytotoxic. Because ceramide is a small lipid molecule, there are limited tools like antibodies to detect its presence. Alternatively, designated machines for small-molecule separation coupled with mass spectrometry detection can be used; however, these can be cost-prohibitive. We used a commercially available NBD-ceramide to apply to human cancer cell lines in the presence or absence of a known SMS inhibitor, jaspine B. After short incubation times, we were able to collect cell lysates and using solvent extraction methods, run the cellular material on a thin-layer chromatography plate to determine the levels of intact fluorescently labeled ceramide. Brighter fluorescence on the TLC plate correlated to greater SMS inhibition. Small molecules can then be screened quantifiably to determine the biological impact of inhibiting the sphingolipid metabolism pathways involving ceramide.