Tropism of the in situ growth from biopsies of childhood neuroectodermal tumors following transplantation into experimental teratoma.

Experimental teratoma induced from human pluripotent stem cells with normal karyotype can be described as a failed embryonic process and includes besides advanced organoid development also large elements of tissue with a prolonged occurrence of immature neural components. Such immature components, although benign, exhibit strong morphological resemblance with tumors of embryonic neuroectodermal origin. Here, we demonstrate that biopsy material from childhood tumors of neural embryonic origin transplanted to mature experimental teratoma can show an exclusive preference for matching tissue.

Early events in xenograft development from the human embryonic stem cell line HS181--resemblance with an initial multiple epiblast formation.

Xenografting is widely used for assessing in vivo pluripotency of human stem cell populations. Here, we report on early to late events in the development of mature experimental teratoma from a well-characterized human embryonic stem cell (HESC) line, HS181. The results show an embryonic process, increasingly chaotic.

Species-specific in vivo engraftment of the human BL melanoma cell line results in an invasive dedifferentiated phenotype not present in xenografts.

For clinically relevant studies on melanoma progression and invasiveness, in vivo experimental systems with a human cellular microenvironment would be advantageous. We have compared tumor formation from a human cutaneous malignant melanoma cell line (BL), after injection as conventional xenografts in the mouse, or when injected into a predominantly species-specific environment of human embryonic stem cell-derived teratoma induced in the mouse (the hEST model). The resulting melanoma histology was generally analogous, both systems showing delimited densely packed areas with pleomorphic cells of malignant appearance.