Positive Health Online

Abstract

LI and COLLEAGUES, 1. Laboratory of Physiological Chemistry, Institute of Medicinal Chemistry, Hoshi University studied the actions of retinol upon proliferation of human gallbladder cancer NOZ C-1 cells.

Background

Among the constituents of the essential nutrient vitamin A, retinol is a potent suppressor of refractory cancer cell growth linked to tumour progression, showing greater efficacy than retinoic acid (RA). However, the mechanisms of retinol action on human refractory cancer are not known well.

Methodology

In the current study, we examined the actions of retinol on proliferation of human gallbladder cancer NOZ C-1 cells.

Results

Retinol and RA inhibited the proliferation of human NOZ C-1 cells in dose-dependent manner, while RA was less potent than retinol. Cell incorporation of RA was approximately two-fold higher than retinol and was not correlated with anti-proliferative activity. Retinol did not affect caspase-3 activity or mRNA expression of Bax and Bcl-2, which are associated with apoptosis. In addition, protein expression of phosphorylated extracellular signal-regulated kinase (p-ERK)/ERK and p-Akt/Akt were not significantly changed by retinol treatment. In contrast, retinol treatment significantly increased the mRNA expression of endoplasmic reticulum (ER) stress factors (heme oxygenase 1 (HMOX1), CCAAT/enhancer-binding protein homologous protein (CHOP), 78 kDa glucose-regulated protein (GRP78), and DnaJ (Hsp40) homolog, subfamily B, member 9 (DNAJB9)). Furthermore, the number of cells in the G0/G1 phase was increased, while the number of cells in the S phase were decreased by retinol treatment. Retinol increased expression of the autophagy-associated protein, LC3-II.

Conclusion

These results indicate that retinol is a potent suppressor of gallbladder cancer cell growth by mechanisms that involve ER stress, which results in autophagy and cell cycle delay. This suggests that retinol might be useful for anticancer prevention and therapy in the clinic.

References

Li C1, Imai M, Hasegawa S, Yamasaki M, Takahashi N. Growth Inhibition of Refractory Human Gallbladder Cancer Cells by Retinol, and Its Mechanism of Action. Biol Pharm Bull. 40(4):495-503. Apr 1 2017. doi: 10.1248/bpb.b16-00934. Epub Jan 18 2017.

Comment

The above research indicate that retinol suppresses gallbladder cancer cell growth, suggesting its introduction into anticancer clinical therapy.