ATRA enhances the expression of 67LR and cell growth inhibitory activity of EGCG.

<p><b>A</b>) Structure of EGCG and ATRA. <b>B</b>) 67LR protein levels in B16 cells exposed to the indicated concentrations of ATRA for 48 h were analyzed by Western blot analysis. Levels of 67LR expression were detected with anti 67LR serum, and were normalized to β-Actin. Band intensities were quantified using NIH Image J software. <b>C</b>) Anti-67LR antibody conjugated with Alexa Fluor 488 (1 mg/ml) was used at a dilution of 1∶100. Photographs were taken under Keyence BZ-8001 fluorescence microscope. <b>D</b>) Cells were counted after treatment with or without 0.5 µM EGCG and/or 0.1 µM ATRA in DMEM supplemented with 1% FCS for 48 h and 96 h each. Cell proliferation was evaluated by counting the number of cells using a Counlter Counter. Data shown are means ± S.D. for three samples. Data containing asterisk marks are significantly different from the values in control at ***<i>p</i><0.001.