agar and Teratoma

The formation of tumor stem cell colonies in vitro has been studied by comparing the growth of three mouse teratocarcinoma derived cell lines and one human teratocarcinoma derived cell line in semi-solid media containing either agar or agarose. We show that agaroses should be used in higher concentrations than agar to obtain comparable results. The maximum number of colonies were obtained in agarose over a broader range of concentrations (1%-4% for SeaPrep and 0.5%-2% for SeaPlaque agarose) than in agar, which allowed anchorage-independent growth of tumor cells only over a narrow concentration range (0.3%-0.5%). Overall, the preparation of media containing agarose was less cumbersome than preparation of agar-containing media, primarily because agaroses gelled more slowly and remained liquid in the physiological temperature range. Furthermore, the transfer of colonies from semi-solid media containing agarose to solid surface tissue culture dishes was much more efficient than the transfer of colonies from agar. The stock solutions of SeaPrep agarose could be kept ready for use for extended periods of time. All these features show that the low melting point agarose has considerable advantages over agar for preparation of semi-solid media for anchorage-independent tumor cell growth.

Topics: Agar; Animals; Culture Media; Embryonal Carcinoma Stem Cells; Mice; Neoplastic Stem Cells; Sepharose; Teratoma

The differentiation pattern of two human germ cell tumors, grown in nude mice and in vitro is described. Tumor A was an embryonal carcinoma (EC) of borderline histology with characteristics of yolk sac tumor and of seminoma; tumor B was a teratocarcinoma with yolk sac elements and syncytiotrophoblastic giant cells. The morphology of an EC as well as cytogenetic characteristics were maintained during 20 passages in nude mice from tumor A and over 11 passages from tumor B. Tumor A did not grow in vitro. Cell suspensions prepared from xenografted tumor B grew into cystic embryoid bodies in semi-solid tissue culture medium. These embryoid bodies showed cuboidal and flattened cells with microvilli, junctional complexes, peripheral microfilaments, and annulated lamellae, reminiscent of the 'inner cell mass' of a blastula and of endoderm, respectively. When such colonies were transplanted into nude mice, however, only tumors with the morphology found in the transplants appeared.

Topics: Agar; Animals; Cell Transformation, Neoplastic; Cells, Cultured; Humans; Male; Mice; Mice, Nude; Microscopy, Electron; Microscopy, Electron, Scanning; Neoplasm Transplantation; Teratoma; Testicular Neoplasms

Formation of morphologically transformed colonies and the ability to grow in semi-solid agar has been compared for 3 different cell lines from hamster embryo and for primary hamster embryo cells. By manipulating the growth conditions, transformed colony morphology and growth in agar could be induced for all cell types studied. Conditions that induced morphologically transformed colonies, also produced growing colonies in agar. One cell line and the primary cells needed the presence of the tumor promoter 12-O-tetradecanoyl phorbol-13-acetate for the expression of transformed morphology and agar growth, while the two other cell lines produced both morphologically transformed colonies and growth in soft agar without any additions. None of the cell lines would produce morphologically transformed colonies in the presence of newborn bovine serum. Likewise, the cells were dependent on fetal bovine serum in order to grow in soft agar, except for one of the cell lines which produced a low number of agar growing colonies in newborn bovine serum. The data indicate a close relation between morphological transformation and growth in soft agar.

Topics: Agar; Animals; Benzo(a)pyrene; Benzopyrenes; Cell Adhesion; Cell Division; Cell Line; Cell Transformation, Neoplastic; Cricetinae; Culture Media; Embryo, Mammalian; Neoplasms, Experimental; Teratoma; Tetradecanoylphorbol Acetate