In their report, Li et al. described that vitamin
A (retinol) inhibits cancer cell growth via endoplasmic reticulum (ER) stress. Retinal is a more potent suppressor of
gallbladder cancer cell growth linked to tumor progression than retinoic acid
(RA). Although cellular incorporation of RA is higher than retinol, it was not correlated with
anti-proliferative activity. Retinol did not induce apoptosis or suppress MEK/ERK and
PI3K/Akt pathways. However, it significantly
increased the expression of ER stress
related genes and autophagy-associated protein (LC3-II) and the number of cells in
the G0/G1 phase. This result
indicates that retinol suppresses gallbladder cancer cell growth by mechanisms
involving ER stress, autophagy, and cell cycle delay.
Retinol might be useful for the prevention and treatment of cancer.