Gene expression of malignant rhabdoid tumor cell lines by reverse transcriptase-polymerase chain reaction.

Malignant rhabdoid tumors (MRT) are characterized by unique neoplastic cells demonstrating phenotypic diversity. By using the reverse transcriptase-polymerase chain reaction, we have detected expression of various genes before and after differentiation induction with four different agents in four established MRT cell lines (TM87-16, STM91-01, TTC642, and TTC549). The agents used in this study were all-trans retinoic acid (RA), 12-O-tetradecanoylphorbol-13-acetate (TPA), interleukin-3, or interferon-gamma. Before and after induction, c-myc, IGF-II, IGF-I receptor, and IGF-II receptor were constitutively expressed by all four cell lines. The neurofilament medium-size (NF-M) was constitutively expressed by the TM87-16 and TTC642, and the S100 protein alpha subunit was expressed by TM87-16, TTC642, and TTC549. Chromogranin A was expressed by TM87-16 only after treatment with either TPA or RA. MyoD, N-myc, tyrosine hydroxylase, N-CAM, trkA, and the S100 protein beta subunit were not expressed by any cell line before or after induction with these agents. All the MRT cell lines in this study except TM87-16 were highly resistant to differentiation induction. The proliferating cells in TM87-16 and TTC642 expressed mRNA profiles characteristic of neuroectoderm.