Cellular Responses by Low-power He-Ne laser Irradiation on Human Lung Cancer Cells

Helium-neon (He-Ne) laser has been used in many clinical fields, and caught our interest on cancer treatment. We conducted the study of He-Ne laser in lung cancer for the sake of the most common cause of cancer deaths worldwide, and up to 50% of the patients with advanced non-small-cell lung cancers with brain metastases. In this study, we used two human lung cancer cell lines A549, H1299, bronchial epithelial cell line BEAS-2B to detect the effects of He-Ne laser on proliferation and migration capabilities by MTT, trypan blue exclusion and wound healing analysis, followed by Western blot analysis to identify the putative signaling pathway evoked by the He-Ne laser. Low-power He-Ne laser slowed H1299 migration by inhibiting Extracellular signal-regulated protein kinases (ERK) phosphorylation, and decreased A549 cell proliferation via p38 up-regulation. However, He-Ne laser increased NT2 cell proliferation and migration activities through ERK activation. The low-power He-Ne laser had diverse effects on different cells, possibly suppressive effect on malignant cells, but growth provocation on pluripotent cells. We proposed that the low-power He-Ne laser renders a beneficial alternative for cancer treatment and for tissue repair.