Germinal tumor invasion and the role of the testicular stroma

Testicular germ cell tumors (TGCTs) are the most frequent neoplasia among young people and their incidence has grown very quickly during recent decades in North America and Europe. Many studies have been carried out in order to elucidate the factors involved in the appearance and progression of these tumors. Little is known about the role of cancer cell-stroma crosstalk in TGCT invasive processes. Here, we review several factors which may be implicated in germ cell tumor progression, such as matrix metal loproteinases, insulin-like growth factor, transforming growth factor beta, the cadherin/catenin complex and integrins. Paradoxically, some of these molecules are also involved in the regulation of normal testicular function. Finally, we discuss prospects for future research on the role of the stroma in the progression and differentiation of male germ cell tumors.