Effects of exposure to repetitive pulsed magnetic stimulation on cell proliferation and expression of heat shock protein 70 in normal and malignant cells.

This study focused on the effects of repetitive pulsed magnetic stimulation (RPMS) on normal and malignant cells of humans. We used three human cell lines, HBL-100 (human normal breast epithelium), MCF-7 (human breast cancer), and HeLa (human cervical cancer). Cell proliferation at 37 degrees C and 40 degrees C and the expression of heat shock protein (HSP) 70 at 37 degrees C, 40 degrees C, and 42 degrees C, before and after the exposure to RPMS, was investigated. Cell proliferation showed no effects of exposure to RPMS in both normal and malignant cells; however, HSP70 expression was increased by RPMS exposure under thermal stress at 40 degrees C and 42 degrees C in HBL-100 and HeLa. We concluded that RPMS exposure potentiates the effect of thermal stress on both normal and malignant cells, and malignant cells derived from different organs respond differently to RPMS exposure. Copyright 1999 Academic Press.