Characterization of Apoptosis-Related Molecular Changes in a Desmoid Tumor of the Chest Wall: Report of a Case

Abstract.

Desmoid tumors are uncommon benign tumors composed of fibrous tissue, which originate from aponeuroses. Little is known about their molecular pathogenesis and the reason that they recur. We report the case of a 20-year-old man with a recurrent desmoid tumor of the chest wall, focusing on our analysis of the apoptosis and its related molecular events. Immunohistochemical examination showed higher expression of antiapoptotic Bcl-2, Bcl-XL, survivin, and the transcription factor, NF-κB, in the recurrent tumor than in the adjoining normal tissue. Proapoptotic Bax was not detected in the tumor. Similar findings were obtained in the original primary tumor. Both tumors had a low apoptotic index according to the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. These changes occurred in the absence of cell proliferation, shown by the absence of both Ki-67 staining and increased telomerase activity. This derangement of apoptosis gives the aggressive desmoid tumor cells a proliferative advantage, and presumably, forms the basis of its high recurrence rate. Therefore, inhibitors of apoptosis proteins (IAPs) may be useful for predicting recurrence. The regulation of apoptosis by antisense therapy against these inhibitors could prove beneficial for overcoming repeated recurrence, even after surgery.