INJECTING stem cells into patients may not be the only way to repair nerve
damage. Cancerous nerve cells may do the same job, and researchers have already
used them to heal spinal lesions in rats.
Jo Velardo, a neurobiologist at the University of Florida in Gainesville,
says tumour cells have some of the same potential as stem cells in that they
lose their identity, can multiply rapidly, and can be coerced into evolving into
other tissues. 鈥淭hey get a bad rap because they start off as a cancer cell,鈥� she
says.
Velardo and her colleagues gave rats spinal injuries in the neck region. Neck
injuries are the most common spinal injuries in people, and can lead to partial
or total loss of movement. The rats all lost the use of one forelimb.
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Velardo then implanted into the partially severed cord cancer cells from a
cultured line called hNT, developed by Layton BioScience of Sunnyvale,
California. Over the course of a year, the cancer cells gradually differentiated
into neurons and filled the lesion. So far, none of the cells has been detected
growing beyond the graft site, as cells that are still cancerous might, Velardo
told the conference.
Velardo says the rats appear to be scampering around a bit better, though she
has yet to carry out a thorough analysis of movement in their forelimbs. Once
preliminary studies are complete, the cells could start clinical trials for
spinal cord injuries as soon as 2002.
While cancer cell therapy might be free of ethical concerns, few researchers
argue that such alternatives make stem cell research unnecessary. Any approach
can appear promising early on and then fail in clinical trials, although two
months ago, hNT cells completed safety trials in humans as a treatment for
stroke, having shown no adverse effects.
We should forge ahead on all fronts, says Ira Black, a neuroscientist at the
Robert Wood Johnson Medical School in New Jersey. 鈥淚f we ever expect to be able
to help those in wheelchairs who suffer from strokes or Alzheimer鈥檚, we must
肠辞苍迟颈苍耻别.鈥�