Fig. 5.

Overexpression of GPRC5A inhibits IL-6-induced STAT3 activation and suppresses anchorage-independent growth in HNSCC. a Immunoblot of the cell lysates from CAL27 and CAL27-GPRC5A stable transfectant cells (CAL27-5A) with the antibodies as indicated. Cells were treated with IL-6 (10 ng/ml) for 15 min. b The growth of CAL27 cell transfected with the pcDNA3.0 and pcDNA3.0-GPRC5A vectors were analyzed using the CCK-8 kit; the symbols represent the mean values of triplicate tests (mean ± SD). c Microphotographs showing colonies from anchorage-independent growth analysis of CAL27-5A and CAL27-V cells. The bar graphs of the mean (and standard error) number of colonies from four wells and the statistically significant differences were indicated as asterisk (P < 0.01) between CAL27-5A and CAL27-V cells (low) (d) Western blot analysis of p-STAT3, STAT3, p-EGFR, EGFR, p-AKT, AKT, P-ERK, ERK from CAL27 cells pretreated with various inhibitors for 1 h followed by stimulation with IL-6 (10 ng/ml) for 15 min