Morphine Suppresses Lung Cancer Cell Proliferation Through the Interaction with Opioid Growth Factor Receptor: An In Vitro and Human Lung Tissue Study.
Kim, Ji Yeon MD, PhD; Ahn, Hyun Joo MD, PhD; Kim, Jin Kyoung MD, PhD; Kim, Jhingook MD, PhD; Lee, Sang Hyun MD; Chae, Hyun Byung MD
Anesthesia & Analgesia.
123(6):1429-1436, December 2016.
(Format: HTML, PDF)
BACKGROUND: There have been inconsistent reports on whether opioids promote or inhibit lung cancer growth. In this study, we suggest that opioid growth factor receptor (OGFR), a negative regulator of cell proliferation, is a binding site of morphine and is involved in subsequent morphine-induced lung cancer growth suppression.
METHODS: The expression and distribution of OGFR in human lung cancer tissues and cell lines were assessed with immunohistochemistry and real-time reverse transcription polymerase chain reaction. The human lung cancer cell line, H1975 (adenocarcinoma), which overexpressed OGFR but not [mu]-opioid receptors, was selected for further analysis to verify the interaction between morphine and OGFR and the impact of morphine on cancer cell growth.
RESULTS: OGFR was expressed in lung cancer tissues and all cancer cell lines tested. Adenocarcinoma showed a higher OGFR expression than squamous cell carcinoma (reverse transcription polymerase chain reaction relative quantitation value: median [interquartile range], 13.1 [9.3-20.0] vs 4.3 [2.2-6.6]; P = 0.003). OGFR expression showed an inverse correlation with cell proliferation (r = -0.92, P = 0.0001). Morphine treatment reduced the median H1975 cell number by approximately 23% (P = 0.03). Growth suppression by morphine was attenuated when OGFR was knocked down. A confocal experiment demonstrated binding of morphine to OGFR. Growth suppression by morphine occurred in the S phase of the cell cycle.
CONCLUSIONS: Lung cancer tissues and cell lines express OGFR. Morphine interacts with OGFR and may suppress lung cancer progression.
(C) 2016 International Anesthesia Research Society