The neurula stage mouse embryo in control of neuroblastoma.

Abstract

The purpose of this study was to determine whether the neurula stage mouse embryo can regulate tumor formation of C-1300-3 neuroblastoma cells. Five neuroblastoma cells were injected into the second somite of neurula stage embryos, and their ability to form tumors was tested, 24 hr later, by transplanting the portion of the embryo containing the cancer cells into the testes of adult mice. Only one-third the number of tumors was obtained in comparison with controls in which (i) five neuroblastoma cells were injected into blocks of liver tissue that were then transplanted into the testes of adult animals or (ii) five C-1300-3 neuroblastoma cells were injected directly into the testes. When five C-1300-3 cells were injected into somites, which had been dissected from embryos, and the injected somites were placed in animals, significantly fewer tumors were obtained in relationship with controls. Although it is not known whether the neuroblastoma cells are induced to differentiate or are killed by the embryonic tissue, the effect appeared to be specific because the tumor-forming ability of L1210 leukemia, B-16 melanoma, embryonal carcinoma 247, and a parietal yolk sac carcinoma was unaffected by somites.Cancer cells can differentiate into benign if hot normal cells: observations were made first with teratocarcinomas (1-3), and subsequently have been made with neuroblastoma (4, 5), leukemias (6, 7), squamous cell carcinomas (8), and adenocarcinomas of the breast and colon (9). Differentiation has been induced in tumors by irradiation (10), chemicals (11), analogues of vitamins (12), and growth factors that control physiologic responses of normal hematopoietic and leukemic cells (13). Clearly, direction of the naturally occurring differentiation of neoplasms could result in a noncytotoxic treatment for cancer (14).Important in this regard is the observation that the mouse blastocyst can regulate embryonal carcinoma cells to the point that they and their offspring take part in normal embryonic development leading to the production of chimeric mice (15)(16)(17)(18)(19). In an attempt to understand the mechanism of this regulation, an assay, based on the ability of the blastocyst to regulate tumor formation of embryonal carcinoma cells, was developed (20). In this assay, the incidence of tumors obtained when single embryonal carcinoma cells were injected into suitable animals was compared with that when the cancer cells were incorporated into blastocysts that were then placed in the same site in the animal. Two of three embryonal carcinomas tested produced tumors in significantly fewer numbers than in control situations, and the reaction had a degree of specificity because the tumor-forming ability of B-16 melanoma cells, sarcoma 180 cells, and L1210 leukemias was not affected by the blastocyst (21). A small but significant degree of abrogation of tumor formation was always observed when C-1300-3 neuroblastoma cells were tested in the assay. This was an unexpected observation because C-1300-3 neuroblastoma cells, ...

Plasticity of the neoplastic phenotype in vivo is regulated by epigenetic factors

“…In addition, studies have documented the participation of teratocarcinoma cells in normal mouse development after their transplantation into the blastocyst (21)(22)(23)(24)(25)(26) and regulation of differentiation of other tumor cell types by appropriate embryonic fields (27,28). These studies suggested that the phenotype expressed by transformed cells is dynamic and subject to normalization in response to epigenetic (microenvironmental) regulation (26).…”

Regulation of melanoma by the embryonic skin.

“…Some success with in vitro culture of 8-to 10-day embryos has been obtained in tissue culture (10,14,15), but later events in development have been studied, usually in organ culture (16) or with avian embryos (17)(18)(19)(20).…”

Cancer as a disorder of patterning information: computational and biophysical perspectives on the cancer problem

“…The morphogenetic field ought to be the most active and accessible during embryogenesis. It is thus not surprising that despite considerable malignancy and aneuploidy, tumor cells introduced into wild-type embryos become integrated (figure 1(C)) as normal tissue [124][125][126][127][128][129][130][131][132][133][134]. Human metastatic melanoma cells injected into zebrafish embryos acquire a non-neoplastic phenotype, but form tumors when injected into zebrafish after organogenesis [135,136].…”