This study aims to detect the expression of
metabotropic glutamate receptors (mGluRs) in lung
carcinoma A549 cells, and to investigate the effects of
mGluR8 and
mGluR4 activation on the growth of A549 cells in vitro. The
mRNA expression levels of the 8 subtypes of mGluRs in A549 cells were determined by real-time PCR. Immunohistochemistry was used to analyze the
protein expression of
mGluR4 and
mGluR8 in A549 cells and lung tissue sections obtained from
lung adenocarcinoma patients. To observe the effects of
mGluR8 and
mGluR4 activation on the growth of A549 cells, the cultured cells were treated with (S)-3,4-DCPG (an agonist of
mGluR8) and
VU0155041 (an agonist of
mGluR4), respectively, and then the cell viability was analyzed by
CCK-8 kit, the percentage of
DNA synthesis was detected by EdU incorporation, and the apoptosis of the cells was measured by
hoechst 33258 staining and flow cytometry. The results showed that there were low expressions of
mGluR1, mGluR5,
mGluR6,
mGluR7 mRNA, no expression of
mGluR2 and
mGluR3 mRNA, and high expressions of
mGluR8 and
mGluR4 mRNA in A549 cells. Accordingly, there were also
mGluR4 and
mGluR8 protein expressions in the A549 cells and the
lung adenocarcinoma tissue sections.
VU0155041 had no effect on the growth of A549 cells, but (S)-3,4-DCPG significantly decreased the cells' growth in a dose-dependent manner and increased the apoptosis of the cells. The results revealed a role of
mGluR8 in the growth and apoptosis of A549 cells and suggested a potential target for clinical treatment of
lung cancer.