APOPTOSIS IN HEMATOPOIETIC PROGENITOR CELLS EXPOSED TO EXTREMELY-LOW-FREQUENCY MAGNETIC-FIELDS

Epidemiological studies have indicated a modestly increased risk for t he development of acute myeloid leukaemia in children who live close t o high-voltage power-lines. Recent evidence has suggested that a commo n property shared by a number of known and suspected tumour promoters is their ability to block the process of apoptosis. Therefore, one pos sible mechanistic explanation for the apparent leukaemogenic effect of weak, low-frequency magnetic fields, such as emitted by power-lines a nd electrical appliances, would be their expression of tumour-promotin g activity by interfering with the regulation of apoptosis in multipot ent haemopoietic progenitor cells. In order to test this hypothesis, w e have employed the well-characterized multipotential haemopoietic pro genitor cell line FDCP-mix(A4). These cells are non-leukaemic and unde rgo apoptosis when deprived of appropriate growth factors such as Inte rleukin-3. We have tested a series of different regimes of weak, low-f requency magnetic fields: nulled fields, Ca2+-ion cyclotron resonance conditions at 50 Hz, and vertical 50 Hz fields of 6 mu T-RMS, 1 mT(RMS ) and 2 mT(RMS), exposing the cells for 2 hours, 24 hours, 4 days or 7 days under various culture conditions. We have not seen any significa nt alteration in apoptosis induced by any of the exposure regimes test ed. We therefore conclude that the regulation of viability and apoptos is in FDCP-mix(A4) cells is not disturbed by weak magnetic fields of t he magnitude and type indicated.