Figure 1. Bcl2 overexpression in synovial sarcoma enhances sarcomagenesis.

A. Schematic of alleles for SS18-SSX2 and Bcl2 overexpression with their respective recombination products (IRES, internal ribosomal entry site).

B. Schematic of TATCre injection technique resulting in the combinatorial expression of hSS2 and Bcl2.

C. Radiograph image of hSS2;Bcl2^OE mouse 8 months post TATCre injection in the right forearm and right hindlimb (black arrow).

D. Photomicrographs of H&E histology examples of monophasic, biphasic, and poorly differentiated synovial sarcomas from hSS2;Bcl2^OE mice induced with TATCre.

E. Schematic of Myf5Cre+ distribution in E11.5 embryo resulting in the expression of hSS2 or hSS2;Bcl2^OE during embryogenesis.

F. Kaplan-Meier plot of the nonmorbid fraction of hSS2;Bcl2^OE (gray) and hSS2;Bcl2^WT (blue) induced in Myf5Cre+ mice. Statistical difference (Log-rank test) between hSS2;Bcl2^OE and hSS2;Bcl2^WT, p value = 0.023.

G. Photomicrographs of H&E histology examples of monophasic, biphasic, and poorly differentiated synovial sarcomas from hSS2;Bcl2^WT and hSS2;Bcl2^OE, mice induced in Myf5Cre+ cells.

H. Fraction of monophasic, biphasic, and poorly differentiated histologies in Myf5Cre;hSS2;Bcl2^WT and Myf5Cre;hSS2;Bcl2^OE, mice.

(All magnification bars = 10 µm)