Expression of human endogenous retrovirus-K coincides with that of micro-RNA-663 and -638 in germ-cell tumor cells.

Background/aim: The cell line GH was established from germ-cell tumor tissue; human endogenous retrovirus-K (HERV-K) expression was detectable after prolonged culture of the cells, particularly in cells that formed domes and vesicles. In addition, keeping GH cells in culture at high cell densities increased HERV-K expression. Here, we studied whether this inducible HERV-K expression is accompanied by differences in microRNA (miRNA) expression patterns of GH cells.

Materials And Methods: The global miRNA expression pattern of GH cell samples (HERV-K high versus low) was analyzed by miRNA arrays.

Results: Two miRNAs were found to be differentially regulated and to exhibit expression parallel to that of HERV-K. The identified miRNAs-663 and -638, have been reported to be involved in multiple processes, including cellular senescence. However, induction of HERV-K expression did not change the cellular senescence status of GH cells.

Conclusion: The expression of these two miRNAs might be useful as novel diagnostic and prognostic markers in patients with tumors.