Exposure to 900 MHz electromagnetic field induces an unbalance between pro-apoptotic and pro-survival signals in T-lymphoblastoid leukemia CCRF-CEM cells.
It has been recently established that low-frequency electromagnetic field (EMFs) exposure induces biological changes and could be associated with increased incidence of cancer, while the issue remains unresolved as to whether high-frequency EMFs can have hazardous effect on health. Epidemiological studies on association between childhood cancers, particularly leukemia and brain cancer, and exposure to low- and high-frequency EMF suggested an etiological role of EMFs in inducing adverse health effects. To investigate whether exposure to high-frequency EMFs could affect in vitro cell survival, we cultured acute T-lymphoblastoid leukemia cells (CCRF-CEM) in the presence of unmodulated 900 MHz EMF, generated by a transverse electromagnetic (TEM) cell, at various exposure times. We evaluated the effects of high-frequency EMF on cell growth rate and apoptosis induction, by cell viability (MTT) test, FACS analysis and DNA ladder, and we investigated pro-apoptotic and pro-survival signaling pathways possibly involved as a function of exposure time by Western blot analysis. At short exposure times (2-12 h), unmodulated 900 MHz EMF induced DNA breaks and early activation of both p53-dependent and -independent apoptotic pathways while longer continuous exposure (24-48 h) determined silencing of pro-apoptotic signals and activation of genes involved in both intracellular (Bcl-2) and extracellular (Ras and Akt1) pro-survival signaling. Overall our results indicate that exposure to 900 MHz continuous wave, after inducing an early self-defense response triggered by DNA damage, could confer to the survivor CCRF-CEM cells a further advantage to survive and proliferate.
Marinelli
F
F
Institute for Organ Transplantation and Immunocytology, ITOI-CNR, Bologna unit, c/o IOR, Bologna, Italy.
La Sala
D
D
Cicciotti
G
G
Cattini
L
L
Trimarchi
C
C
Putti
S
S
Zamparelli
A
A
Giuliani
L
L
Tomassetti
G
G
Cinti
Caterina
C
D017209:Apoptosis / Q000528:radiation effects*; D015153:Blotting, Western; D002453:Cell Cycle / Q000235:genetics / Q000528:radiation effects; D002455:Cell Division / Q000528:radiation effects; D004574:Electromagnetic Fields / Q000009:adverse effects*; D015870:Gene Expression / Q000528:radiation effects*; D006801:Humans; D007962:Leukocytes / Q000528:radiation effects*; D013997:Time Factors; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000528:radiation effects
D016159:Tumor Suppressor Protein p53