Normal genetically mosaic mice produced from malignant teratocarcinoma cells.

Abstract

3585The most rigorous test possible for developmental totipotency would be significant contributions of the carcinoma cells to the normal differentiation of virtually all tissues in a mouse. For this to occur, the initially malignant cells would presumably have to be brought into association with early embryo cells so that the latter could provide an organizational framework appropriate for normal development. The experiment is analogous to production of allophenic mice (6).The projected teratoma studies in this laboratory involve the use of mutagenized embryonal carcinoma cells for experimental analyses of genetic regulatory systems in mammalian differentiation (7). The most promising source of baseline, or nonmutagenized, cells appears to be from the cores of small embryoid bodies grown only in vivo, as these would be less likely to have accumulated genetic changes than would cells cultivated in vitro. Most in vitro teratocarcinoma cell lines do not in fact have a normal chromosome number and some have lost multipotentiality (8-11), whereas the tumors from which they originated were diploid (12).We report here that teratocarcinoma cells taken from the cores of embryoid bodies grown only in vivo for 8 years, during which they retained a euploid chromosome complement, appear to be developmentally totipotent. The original conversion to malignancy in all likelihood did not involve mutational events and has proved to be completely reversible to normalcy. A partial report of these results has been presented (7). MATERIALS AND METHODSCore Cells. The OTT 6050 ascites teratoma, originally received from Dr. L. C. Stevens, has been maintained by intraperitoneal transfers every 2-3 weeks in syngeneic males of the 129/Sv SlJ C P inbred strain (to be referred to as 129) (see Fig. 1). To obtain core cells, only small-size embryoid bodies were collected, in Dulbecco's phosphate-buffered saline (PBS), by filtration of ascites fluid through 100 /Am Nitex mesh (13). They were subjected to light proteolytic treatment for approximately 3 min in 0.25% trypsin (crystalline, Worthington) and 1.25% pancreatin (Difco) in PBS; proteolysis was stopped in Dulbecco's modification of Eagle's medium (DMEM) with 50% fetal calf serum (FCS) (Gibco). Addition of 5 ,gg/ml of DNase eliminated stickiness.After about 15 min, the embryoid bodies were centrifuged and transferred to DMEM with 15% FCS and organic buffers [10 mM N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (Hepes) and 10 mM morpholinopropane sulfonic acid (Mops)], and the epithelium was peeled off with tungsten needles. The cores (Fig. 3) were then partially dissociat- [+/+].) The embryo was placed under a testis capsule, where it became disorganized, forming a teratoma which metastasized to a renal node. The primary tumor was minced and transplanted intraperitoneally; it became an ascites tumor of "embryoid bodies" with yolk sac "rinds" and teratocarcinoma (or embryonal carcinoma) "cores". In 1975, after almost 200 transplant generations in syngeneic hosts, the rinds of some...

Involvement of l(–)-rhamnose in sea urchin gastrulation: a live embryo assay

“…Results showed that once the embryos were born they were hybrid mice (Mintz and Illmensee, 1975), meaning that some of the offspring cells were derived from normal embryonic tissues and some were derived from the cancerous cells (Mintz and Illmensee, 1975). However, the mice were healthy and tumor-free (Mintz and Illmensee, 1975). This study illustrates the similarities in signaling and communication between the two cell types (Mintz and Illmensee, 1975).…”

“…In this investigation, teratocarcinoma cells were injected into mouse embryos, and the embryos into a mouse surrogate mother (Mintz and Illmensee, 1975). Results showed that once the embryos were born they were hybrid mice (Mintz and Illmensee, 1975), meaning that some of the offspring cells were derived from normal embryonic tissues and some were derived from the cancerous cells (Mintz and Illmensee, 1975). However, the mice were healthy and tumor-free (Mintz and Illmensee, 1975).…”

“…There has been pivotal research that has been able to connect embryonic cells to cancerous cells. One study that links cancer biology to developmental biology was a study conducted by Beatrice Mintz and Karl Illmensee (Mintz and Illmensee, 1975). In this investigation, teratocarcinoma cells were injected into mouse embryos, and the embryos into a mouse surrogate mother (Mintz and Illmensee, 1975).…”

“…One study that links cancer biology to developmental biology was a study conducted by Beatrice Mintz and Karl Illmensee (Mintz and Illmensee, 1975). In this investigation, teratocarcinoma cells were injected into mouse embryos, and the embryos into a mouse surrogate mother (Mintz and Illmensee, 1975). Results showed that once the embryos were born they were hybrid mice (Mintz and Illmensee, 1975), meaning that some of the offspring cells were derived from normal embryonic tissues and some were derived from the cancerous cells (Mintz and Illmensee, 1975).…”

A new theory of carcinogenesis

“…Teratocarcinoma cells are pluripotent and give rise to a variety of differentiated cell types in vivo as well as in culture. When genetically marked teratoma cells are injected into mouse blastocysts they can be recovered in a variety of tissues in the fully developed animals (Mintz & Illmensee, 1975;Papaioannou et al, 1975). These cell-transplantation experiments do not prove that the genetic material of these tumour cells is completely normal, but they certainly show that the tumour-cell phenotype can be reversed when the teratoma cell finds itself in a cellular environment where reprogramming can occur.…”