To identify circular RNAs abundantly expressed in Undifferentianted Pleiomorphic Sarcoma, and to illuminate how circRNAs catalyze cancer-promoting and drug-resisting conditions in the microenvironment surrounding tumor cells. In particular, we will study how circRNAs merge with RNAbinding proteins to powerfully modulate tumor cell secretions, which in turn forge a tumor-protective niche that renders many existing therapies ineffective against UPS. Finally, we will use newly developed molecular techniques to manipulate circRNAs in tumor cells, paving the way to design transcriptional therapies against UPS, and to use circRNAs to refashion the tumor microenvironment, rendering this intractable disease newly vulnerable to previously failed therapies.