Enhancement of anchorage-independent growth in JB6 cells exposed to 60 hertz magnetic fields

West, Robert W.; Hinson, William G.; Lyle, Daniel B.; Swicord, Mays L.

doi:10.1016/0302-4598(94)80007-3

Cited by 21 publications

(17 citation statements)

References 14 publications

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“…In tests to determine reasons for the discrepancy between our results and those reported by West et al (9,10), factors such as serum lot, cell-plating technique, the effect of increasing or decreasing the time the cells are held at 42°C prior to plating, and other experimenter-dependent factors were examined. Of the factors above, serum lot and cell plating order had the greatest effect on colony formation.…”

Section: Methodsmentioning

confidence: 60%

“…(9); cells, serum, and other cell culture supplies were either from the same commercial source or supplied by West. The methods used in the present study were identical to those of West et al (9,10) except for the use of the DOE regional facility for cell exposures. Despite these efforts, our findings were different than those previously reported (9,10 10 days.…”

Section: Discussionmentioning

confidence: 99%

“…The methods used in the present study were identical to those of West et al (9,10) except for the use of the DOE regional facility for cell exposures. Despite these efforts, our findings were different than those previously reported (9,10 10 days. However, we chose to indude these experiments as valid replications for two reasons.…”

Section: Discussionmentioning

confidence: 99%

“…Plasticware, media, serum, and all other reagents were obtained from identical commercial sources as used previously by West et al (9) with appropriate concentrations of TPA. For these assays, three sets (A, B, C) of three or more replications per treatment were used in each assay.…”

Section: Methodsmentioning

confidence: 99%

“…Increased colony growth has been observed in JB6 cells treated with phorbol esters, epidermal growth factor, lanthanides, and phthalate esters ($). West et al (9) reported that 60-Hz sinusoidal MF exposure altered the growth of promotion-sensitive JB6 cells under anchorageindependent conditions. In their research, exposure of cells to a continuous 1.1 -mT MF (11 G) led to significant increases in the soft agar colony-forming efficiency, i.e., 40-70% greater numbers compared with unexposed cells (>95% confidence level), at 10-14 days of MF exposure.…”

mentioning

confidence: 99%

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Effect of Magnetic Field Exposure on Anchorage-Independent Growth of a Promoter-Sensitive Mouse Epidermal Cell Line (JB6)

Snawder¹,

Edwards²,

Conover³

et al. 1999

Environmental Health Perspectives

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The anchorage-independent growth of mouse epidermal cells (JB6) exposed to 60-Hz magnetic fields (ME) was investigated. Promotion-responsive JB6 ceils were suspended in agar (104 cells/plate) and exposed contitnuously to 0.10 or 0.96 mT, 60-Hz magnetic fields for 10-14 days, with or w.ithout concurent treatment with the tumor promoter tetrdcnoylphorbol acetate (TPA). Exposures to ME were cotnducted in a manner such ta the epermenter was blind to the treatment group of the cells. At the end of the eosue perio the anchorageindependent growth of JB6 cells on soft ap.r wa ined by couting the number of colonies larger than 60 pm (minimum of 60 cells). The use of a combnd eatment of the cels withh both MF and TPA was to provide an interal positive control to esutmate the success of the assay and to allow evaluation of co-promotion. Statistica analysis was performed by a randomized block design. alysis of varianme t exmine both the effect of TPA treatment (alone and in combination with MF exposure) an he efect of intraassriability. Transformation fre n ofJB6 ces displayed a d d response o increasing con centrations of TPA. Coexosue of cells to both TPA and 0.10 or 0 mT, 60-Hz MF did not result in any difierences in trIsfrmation frequency for any TPA concentrations tested (0-1 ng/mli). These data idicate tt exsure to a 0..10 or 0.96 mT, 60Hz MF does not act as a promoter or co-promoter in promotion-sensitive JB6 cel anchor independent growth. Ky work cancer promotion, JB6 cell proliferation, low frcquency magnetic.fields. Environ

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Section: Methodsmentioning

confidence: 60%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Effect of Magnetic Field Exposure on Anchorage-Independent Growth of a Promoter-Sensitive Mouse Epidermal Cell Line (JB6)

Snawder¹,

Edwards²,

Conover³

et al. 1999

Environmental Health Perspectives

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Influence of 50-Hz magnetic fields and ionizing radiation onc-jun andc-fos oncoproteins

Lagroye

Poncy

1998

Bioelectromagnetics

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The effect of magnetic fields (50 Hz, 100 μTrms sinusoidal magnetic field combined with a 55 μT geomagnetic‐like field) and/or gamma rays of 60 Cobalt on the expression of the c‐jun and c‐fos proteins was investigated in primary rat tracheal epithelial cells and two related immortalized cell lines. Quite similar patterns and amplitudes of induction of these proteins were evidenced after either ionizing radiation or magnetic field exposure. No synergism after both treatments was observed. These findings suggest that magnetic fields explored in the present study may be considered as an insult at the cellular level. Bioelectromagnetics 19: 112–116, 1998. © 1998 Wiley‐Liss, Inc.

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Induction of stress proteins by electromagnetic fields in cultured HL-60 cells

Pipkin

Hinson

Young

et al. 1999

Bioelectromagnetics

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HL‐60 cells in culture were exposed for 2 h to a sinusoidal 0.1 or 1 mT (1 or 10 Gauss) magnetic field at 60 Hz and pulse labeled after exposure with radioactive isotopes by incubation by using either [35S]methionine, [3H]leucine, or [33P]phosphate. The radioactive labels were incorporated into cellular proteins through synthesis or phosphorylation. Proteins were extracted from electrostatically sorted nuclei, and the heat shock/stress proteins (sp) were analyzed for synthesis and phosphorylation by two‐dimensional polyacrylamide gel electrophoresis. In the control cultures (no exposure to the magnetic field), sp 72c (cognate form) was faintly observed. A 0.1 mT exposure did not show sp metabolism to be different from that of the controls; however, after a 1 mT exposure of the HL‐60 cells, sp 70i (inducible form) was synthesized ([35S]methionine incorporation). Sp 90 was not synthesized at either field level, but was phosphorylated ([33P]phosphate incorporation) in the 1 mT exposure. Sp 27 (isoforms a and b) was induced after a 1 mT exposure as reflected by labeling with [3H]leucine. These sps were not detected after a 0.1 mT exposure. After a 1 mT exposure and labeling with [33P], sp 27 isoforms b and c were phosphorylated whereas isoform ‘a‘ was not observed. Sps 70i, 72c, and 90 were identified by commercial sp antibodies. Likewise, polypeptides a, b, and c were verified as sp 27 isoforms by Western blotting. Statistical evaluation of sp areas and densities, determined from fluorographs by Western‐blot analysis, revealed a significant increase in sps 90 and 27a after a 1 mT magnetic field exposure. The 1 mT magnetic field interacts at the cellular level to induce a variety of sp species. Bioelectromagnetics 20:347–357, 1999. Published 1999 Wiley‐Liss, Inc.

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Enhancement of anchorage-independent growth in JB6 cells exposed to 60 hertz magnetic fields

Cited by 21 publications

References 14 publications

Effect of Magnetic Field Exposure on Anchorage-Independent Growth of a Promoter-Sensitive Mouse Epidermal Cell Line (JB6)

Effect of Magnetic Field Exposure on Anchorage-Independent Growth of a Promoter-Sensitive Mouse Epidermal Cell Line (JB6)

Influence of 50-Hz magnetic fields and ionizing radiation onc-jun andc-fos oncoproteins

Induction of stress proteins by electromagnetic fields in cultured HL-60 cells

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