SMYD2 inhibition decreases TMPRSS2 expression in cultured HT-29 cells. (A) LDH release assay from HT-29 cells stimulated with increasing concentrations of AZ505, AZ506, LLY507, or BAY598 for 24 h. Experiments were performed two times and representative data of one experiment are shown. * p < 0.05 and *** p < 0.001. N.S., not significant. (B) Immunofluorescence staining of TMPRSS2 in HT-29 cells stimulated with vehicle (mock), 10 µM AZ505, 10 µM AZ506, 10 µM LLY507, or 20 µM BAY598 for 8 h. Scale bar, 10 µm. (C) Immunoblot analysis of TMPRSS2 in lysates of HT-29 cells at different time points upon treatment with 20 µM BAY598. β-actin served as a loading control. (D) Densitometric analysis of TMPRSS2 expression.