In a recent study, Dr. Yuri Lazebnik
and his colleagues at Cold Spring Harbor Laboratory observed, fortuitously,
that normal cultured human
cells are fused by the action of the Mason-Pfizer Monkey Virus (MPMV),
but that the resulting hybrid cells do indeed fail to proliferate.
However, the researchers discovered that if one of the fusion partners
carried a particular "predisposing" gene mutation (in the
oncogenes E1A or Myc, or in the tumor suppressor gene p53), then
a significant proportion of the resulting hybrid cells were highly
proliferative and thus potentially cancerous.
Whether such proliferating hybrid cells are produced by viruses in the human
body, whether they can lead to cancer, and which of the many known and candidate
human fusogenic viruses (for example, endogenous retroviruses, whose DNA sequences
comprise at least 8% of the human genome) might contribute to cancer remain to
be determined.
In addition to revealing that common viruses might contribute to cancer by fusing
cells, the researchers report that the use of fusogenic viruses as vectors for
gene therapy or in other clinical applications should be carefully evaluated.
The lead author of the study was Dr. Dominik Duelli, a postdoctoral fellow at
Cold Spring Harbor Laboratory.
The study appeared in the November 7 issue of the Journal of Cell Biology.
For more information, visit
www.cshl.edu.