Discrete subsets of myogenic and mesenchymal precursors give rise to soft tissue sarcomas of distinct lineage differentiation

This work examines sarcoma formation within discrete subsets of KRAS(G12V)-expressing p16p19null myogenic and mesenchymal cells found normally in skeletal muscle. We show that prospectively isolated skeletal muscle precursor cells (SMPs) within the satellite cell pool can serve as cancer cells-of-origin for mouse rhabdomyosarcomas (soft tissue sarcomas with features of myogenic differentiation). Alternatively, non-myogenic progenitors (ScaPCs) induce sarcomas lacking myogenic differentiation markers. We used Affymetrix whole mouse genome 430 2.0 microarrays to gain deeper insights into the molecular underpinnings of the three types of KRAS; p16p19null mouse soft-tissue sarcomas (originating from SMPs, ScaPCs and CD45-MAC1-TER119-Sca1-CXCR4- cells). Four replicates of each type.