title: Angiogenesis and vascular network of teratocarcinoma from embryonic stem cell transplant into seminiferous tubules.
abstract: BACKGROUND
  Carcinoma in situ (CIS) of the testis is considered to be a precancerous germinal cell lesion, but the precise cellular and molecular mechanisms underlying transformation of CIS into invasive pluripotent cancer cells remain to be elucidated. Moreover, a satisfactory animal model for the experimental study of germinal tumours has not been developed to date.
  
  
  METHODS
  We have developed a tumour model that involves the microinjection of green fluorescent protein-labelled embryonic stem (ES) cells (which are functionally equivalent to CIS cells) into syngenic mouse seminiferous tubules, a unique cell microenvironment in which germinal cells mature and CIS arise. To characterise the vascularisation of teratocarcinomas, which arise after cell transplant, we used immunohistochemistry, together with a qualitative and quantitative analysis of scanning electron microscopy images of corrosion casting samples.
  
  
  RESULTS
  Embryonic stem cells transplanted into seminiferous tubules did not differentiate into germinal cells, but rather they behaved as invasive embryonal carcinoma (EC) stem cells. The vascular pattern of the experimental teratocarcinomas showed a highly disorganised architecture, and some of the neoplastic capillaries were derived, at least in part, from the original transplanted ES cells.
  
  
  CONCLUSIONS
  The transplantation of pluripotent ES cells into seminiferous tubules efficiently recapitulates the early stages of development of teratocarcinomas. Consequently, this method constitutes a novel in vivo model to study the mechanisms of invasion and progression of experimental germinal tumours.
authors.affiliation: Laboratory of Stem Cells, Development and Cancer, Department of Cell Biology and Histology, Leioa, Vizcaya, Spain.
authors.forename: U
authors.initials: U
authors.lastname: Silván
authors.forename: J
authors.initials: J
authors.lastname: Arlucea
authors.forename: R
authors.initials: R
authors.lastname: Andrade
authors.forename: A
authors.initials: A
authors.lastname: Díez-Torre
authors.forename: M
authors.initials: M
authors.lastname: Silió
authors.forename: M A
authors.initials: MA
authors.lastname: Konerding
authors.forename: J
authors.initials: J
authors.lastname: Aréchaga
mesh_terms: D000818:Animals; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D054278:Embryonal Carcinoma Stem Cells / Q000473:pathology*; D008297:Male; D051379:Mice; D009389:Neovascularization, Pathologic / Q000473:pathology; D039904:Pluripotent Stem Cells / Q000473:pathology* / Q000637:transplantation; D012671:Seminiferous Tubules / Q000473:pathology*; D033581:Stem Cell Transplantation; D018243:Teratocarcinoma / Q000098:blood supply* / Q000473:pathology*; D013736:Testicular Neoplasms / Q000098:blood supply* / Q000473:pathology*