agar and Carcinoma--Papillary

Beta-thymosins are structurally related, highly conserved acidic polypeptides, originally isolated from calf thymus. We have recently shown that the TB10 gene is overexpressed in human thyroid carcinoma cell lines and tissues, particularly in undifferentiated thyroid carcinomas, but expressed at an undetectable level in normal thyroid cells. The precise role of thymosin beta-10 (TB10) activity in maintaining the malignant phenotype of thyroid cell lines is unknown. To investigate TB10 function and relevance in a model system we used an antisense methodology to suppress TB10 protein synthesis in two human thyroid carcinoma cell lines (NPA and ARO). The growth in soft agar of NPA and ARO cells carrying a TB10 construct in an antisense orientation was significantly reduced. Conversely, anchorage-dependent growth was unchanged in NPA and ARO cells carrying the TB10 construct in a sense orientation or carrying the backbone vector. TB10 expression also affected actin organization. In fact, stress fibers were long and thick in ARO cells in which TB10 expression was suppressed by the antisense construct. Conversely, they were scarce and short in the vector-transfected ARO cells. These data suggest that TB10 plays a critical role in the regulation of anchorage-independent growth and assembly of actin filaments.

Topics: Agar; Antisense Elements (Genetics); Carcinoma, Papillary; Cell Adhesion; Cell Division; Culture Media; Gene Expression Regulation, Neoplastic; Humans; Phenotype; Stress Fibers; Thymosin; Thyroid Neoplasms; Transfection; Tumor Cells, Cultured

A new human ovarian cancer cell line has been initiated which clones without agar in vitro. The cell line has been characterized by growth of a tumor resembling the primary tumor in a nude mouse, by human lactic dehydrogenase isozyme pattern, by human karyotype, and by lack of contamination by other cell lines. Initial studies have demonstrated the presence of epidermal growth factor receptors in this cell line. The utility of this line for clonogenic studies is demonstrated by dose-response studies with doxorubicin, cisplatinum, and 13-cis-retinoic acid.

Topics: Agar; Aged; Animals; Antineoplastic Agents; Carcinoma, Papillary; Cell Division; Cell Line; ErbB Receptors; Female; Humans; Isoenzymes; Karyotyping; Mice; Mice, Nude; Neoplasm Transplantation; Ovarian Neoplasms; Receptors, Cell Surface; Tumor Stem Cell Assay