Induction of receptor activator of nuclear factor-κB ligand (RANKL) by knockdown in guanine nucleotide-binding protein G(q) subunit alpha expression (GNAQ). The expression level of RANKL mRNA was determined by a) real-time polymerase chain reaction and b) semi-quantitative polymerase chain reaction. c) Protein levels of RANKL were determined by western blotting. d) Representative images of tartrate-resistant acid phosphatase (TRAP) staining after induction of osteoclastogenesis by co-culture of RAW 264.7 cells with A549, short hairpin RNA negative control lentiviral vector (A549_shNC), or GNAQ short hairpin RNA lentiviral vector (A549_shGNAQ) cells. Cells were 1:1 co-cultured and treated with RANKL (50 ng/ml) and macrophage colony-stimulating factor (M-CSF, 20 ng/ml). The number of TRAP-positive cells was higher in the GNAQ knockdown group than in the control group. Images were captured using a light microscope (magnification × 40 or × 200). e) Evaluation of the number of TRAP-positive cells (n = 3). Error bars represent mean (SD). *Statistically significant (p < 0.001). †Statistically significant (p < 0.05). GAPDH, glyceraldehyde 3-phosphate dehydrogenase.