N-(4-hydroxyphenyl) retinamide inhibits migration of renal carcinoma cells and promotes autophagy via MAPK p38 pathway
Purpose: To investigate the effect of N-(4-hydroxyphenyl) retinamide (4HPR) on autophagy and migration of renal carcinoma cells.
Methods: Renal cancer cell lines were treated with various concentrations of 4HPR. Proliferation of the cells was studied using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltrazolium bromide (MTT), while apoptosis and cell cycle arrest were determined by flow cytometry.
Results: Treatment of RCCs with 30 μM 4HPR caused significant inhibition of viability. In 786-O and OS-RC-2 cell lines, 4HPR reduced colony formation by 39 and 43 %, respectively. In addition, 4HPR increased the percentage of 786-O cells in G1 phase from 58.79 ± 3.43 to 71.68 ± 4.47 % (p < 0.05). It also decreased the percentage of cells in the S-phase from 21.98 ± 2.78 to 09.17 ± 1.43 %, and enhanced the activation of p38 and JNK in 786-O cells at 48 h. Western blot assay showed that the activation of p38 and JNK by 4HPR was inhibited on pre-treatment with SB203580 (inhibitor of p38) and SP600125 (inhibitor of JNK), respectively. Reduction of 786-O cell viability by 4HPR treatment was also significantly inhibited by pre-treatment with sp203580 and sp600125 (p < 0.05). Furthermore, the inhibitors also reversed the effect of 4HPR on the expressions of Bax and Bcl-2 in 786-O cells.
Conclusion: These results indicate that 4HPR inhibits the growth of renal cancer cells via activation of MAPK signalling pathway. Thus, 4HPR is a potential drug target for management of renal cancer.
Keywords: Retinamide, Renal cancer, Autophagy, MAPK signalling, Cell proliferation, N-terminal kinase