Sequence variability of retroviral particles derived from human melanoma cells: Melanoma-associated retrovirus

We have shown that melanoma cells produce viral particles that contain sequences which are homologous to human endogenous retroviruses. In this study particles derived from different melanoma cell lines and from melanoma cells of a lymph node metastasis were characterized. We determined the density and the reverse transcriptase (RT) activity of viral particles. Furthermore, we analyzed the sequence variability of multiple clones of each particle preparation. The particles were found to package sequences, which vary for each of the analyzed cell lines. Moreover, even particles derived from the same cell line contain heterologous sequences.