Open AccessImmunomodulatory effect of melatonin in SK ‐ LU ‐1 human lung adenocarcinoma cells co‐cultured with peripheral blood mononuclear cells
Author(s) -
Plaimee P.,
Khamphio M.,
Weerapreeyakul N.,
Barusrux S.,
Johns N. P.
Publication year - 2014
Publication title -
cell proliferation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.647
H-Index - 74
eISSN - 1365-2184
pISSN - 0960-7722
DOI - 10.1111/cpr.12119
Subject(s) - melatonin , propidium iodide , peripheral blood mononuclear cell , intracellular , oxidative stress , apoptosis , cell culture , microbiology and biotechnology , cancer cell , annexin , chemistry , biology , programmed cell death , endocrinology , biochemistry , medicine , cancer , in vitro , genetics
Abstract Objectives The anti‐cancer potential of melatonin has been examined using a variety of experimental approaches. Melatonin immunomodulatory action was evaluated against the lung cancer cell line SK ‐ LU ‐1, in co‐culture with human peripheral blood mononuclear cells ( PBMC ). Materials and methods Melatonin was tested on the cell line only after 24 h incubation (direct effect), and on the co‐culture system of SK ‐ LU ‐1 and PBMC to investigate any indirect effect. Apoptotic induction of the cancer cells was assessed using annexin V/ PI staining with flow cytometric analysis for membrane alteration. Intracellular superoxide anion (O 2 • − ) and hydrogen peroxide (H 2 O 2 ) for intracellular oxidative stress and glutathione ( GSH ) for intracellular anti‐oxidation were measured with specific fluorescence probes. DNA fractions were measured employing propidium iodide ( PI ) fluorescence staining. Results High doses of melatonin were directly toxic to SK ‐ LU ‐1 cells, while PBMC ‐mediated indirect effect occurred after moderate doses (1 μ m ). Under co‐culture conditions, increases in apoptotic cell death, increase in oxidative stress by reduction of GSH and cell cycle arrest in G 0 /G 1 in SK ‐ LU ‐1 cells, were observed as the immunomodulatory effect of melatonin. Conclusion Melatonin had indirect effects on lung cancer cells by enhancement of immunomodulatory effects, but further studies of mechanism(s) involved are needed.