Fig. 3

Waixenicin A inhibits cell proliferation of HT-29. a q-PCR analysis represented the ratio of TRPM7 mRNA to the housekeeping gene β-actin 72 h after HT-29 cell transfection with 20 nM of TRPM7 siRNA or scramble siRNA. *p < 0.01 vs. scramble siRNA. n = 3 experiments. b Endogenous TRPM7-like currents at +80 mV 72 h after HT-29 cell transfection with 20 nM of TRPM7 (open circles, n = 8), TRPM6 (open squares, n = 6) or scramble siRNA (filled circles, n = 8). c Mg²⁺ involvement in proliferation of HT-29. Cell proliferation was examined at 72 h after incubation of scramble siRNA, TRPM7 siRNA, TRPM6 siRNA, TRPM7 siRNA combined with TRPM6 siRNA, 50 μM Mg²⁺, or 10 μM waixA with or without the presence of 10 mM Mg²⁺ (*p < 0.05 vs. Control, n = 3). d Normalized total cell count of HT-29 treated with different concentrations of waixA for various periods of time and analyzed via ViCell assay (n = 3). e Dose-response curve for total cell count at day 4 with different concentrations of waixA (IC₅₀ = 12.7 μM; Hill coefficient = 1.67). Total cell count of untreated control represents 100% of proliferation. f Cell viability in dependence of increasing waixA concentrations as assessed using the MTT assay (n = 3). g Expression profile of putative Mg²⁺ transporters in HT-29 cells established by q-PCR (n = 3)