Author/Editor		Knežević, Vladimir; Poljak, Mario; Bradamante, Želimir; Šerman, Draško; Levak-Švajger, Božica; Švajger, Anton
Title		Yolk sac carcinoma derived from the rat epiblast as a renal isograft
Type		članek
Source		Coll Antropol
Vol. and No.		Letnik 29, št. 1
Publication year		2005
Volume		str. 189-97
Language		eng
Abstract		We report the novel observation that alpha biphasic, parieto-visceral (PYS / VYS) yolk sac carcinoma can develop from the isolated epiblast of the pre-primitive streak rat embryo in a prolonged cultivation in vivo as a renal isograft. Late 7-day rat egg cylinders were dissected free of the ectoplacental cone and the Reichert's membrane. The middle segment of the cylinder, in which the embryonic and the extraembryonic cell layers partly overlap, were also removed. From the rest of the cylinder the 4 cell layers were isolated and transplanted separately under the kidney capsule of isogenic adult males. After 4 weeks the hypoblast was resorbed, the extraembryonic ectoderm gave rise to hemorrhagic cysts and trophoblastic giant cells, the extraembryonic (visceral yolk sac) endoderm formed benign cystic PYS / VYS tumors, and the epiblast developed into a benign teratoma. After prolonged (7-30 weeks) development of these teratomas as isografts, a malignant yolk sac carcinama (YSC) developed in 45% of them. It destroyed the teratoma and the recipient's kidney, metastasized to peritoneum and other sites, and caused abundant ascites containing clustered tumor cells. The primary tumor was retransplantable subcutaneously as well as intraperitoneally, and clisplayed the characteristics of the mixed or biphasic PVYS carcinoma, with a progressive loss of the VYS component with time. Several data are apparently in favor of its origin by transdifferentiation rather than from undifferentiated cells.
Descriptors		TERATOMA KIDNEY NEOPLASMS CARCINOMA ENDODERMAL SINUS TUMOR RATS ASCITES KIDNEY TRANSPLANTATION NEOPLASM METASTASIS NEOPLASMS, EXPERIMENTAL EMBRYO