Abstract
Increasing evidence demonstrates that three classes of molecules originally derived from all-trans-retinoic acid and its synthetic analogues, which function by interacting with the retinoid nuclear receptors, exert their anticancer activities through alternative signaling pathways. Thus, the methylene-linked analogues (4-HBR, 4-HPRCG, and 4-HBRCG) of N-(4-hydroxyphenyl) retinamide (4-HPR) and its O-glucuronide metabolite (4-HPROG), the cinnamic acid analogues (3- Cl-AHPC and AHPC/ST1926) of 6-[3-(1-adamantyl)-4-hydroxyphenyl)]-2-naphthalenecarboxylic acid, and N-(2,3- dihydro-2,2,4,4-tetramethyl-6-benzothiopyranyl),N-(4-nitrophenyl)thiourea (SHetA2) induce cancer cell-cycle arrest and apoptosis mediated most likely through mitochondrial and/or endoplasmic reticulum stress responses. Structure – activity relationships and potential for clinical translation as anticancer therapeutics are presented.
Keywords: 3-Cl-AHPC, 4-HPR, AHPC, AHPN, apoptosis, cell-cycle arrest, retinoid-related molecule, SHetA2, ST1926