RESUMEN
This study investigates the breadth of cellular responses engendered by short chain fatty acid (SCFA)-hexosamine hybrid molecules, a class of compounds long used in "metabolic glycoengineering" that are now emerging as drug candidates. First, a "mix and match" strategy showed that different SCFA (n-butyrate and acetate) appended to the same core sugar altered biological activity, complementing previous results [Campbell et al. J. Med. Chem. 2008, 51, 8135-8147] where a single type of SCFA elicited distinct responses. Microarray profiling then compared transcriptional responses engendered by regioisomerically modified ManNAc, GlcNAc, and GalNAc analogues in MDA-MB-231 cells. These data, which were validated by qRT-PCR or Western analysis for ID1, TP53, HPSE, NQO1, EGR1, and VEGFA, showed a two-pronged response where a core set of genes was coordinately regulated by all analogues while each analogue simultaneously uniquely regulated a larger number of genes. Finally, AutoDock modeling supported a mechanism where the analogues directly interact with elements of the NF-kappaB pathway. Together, these results establish the SCFA-hexosamine template as a versatile platform for modulating biological activity and developing new therapeutics.
Asunto(s)
Ácidos Grasos Volátiles/síntesis química , Expresión Génica/efectos de los fármacos , Hexosaminas/síntesis química , Acilación , Apoptosis , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Descubrimiento de Drogas , Proteína 1 de la Respuesta de Crecimiento Precoz/biosíntesis , Proteína 1 de la Respuesta de Crecimiento Precoz/genética , Ácidos Grasos Volátiles/química , Ácidos Grasos Volátiles/farmacología , Perfilación de la Expresión Génica , Glucuronidasa/biosíntesis , Glucuronidasa/genética , Hexosaminas/química , Hexosaminas/farmacología , Humanos , Modelos Moleculares , Mucina-1/biosíntesis , Ácido N-Acetilneuramínico/biosíntesis , FN-kappa B/biosíntesis , FN-kappa B/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , Oncogenes , Transducción de Señal , Relación Estructura-Actividad , Transcripción Genética , Proteína p53 Supresora de Tumor/biosíntesis , Proteína p53 Supresora de Tumor/genéticaRESUMEN
Chemical biology studies, exemplified by metabolic glycoengineering experiments that employ short chain fatty acid (SCFA)-hexosamine monosaccharide hybrid molecules, often suffer from off-target effects. Here we demonstrate that systematic structure-activity relationship (SAR) studies can deconvolute multiple biological activities of SCFA-hexosamine analogues by demonstrating that triacylated monosaccharides, including both n-butyrate- and acetate-modified ManNAc analogues, had dramatically different activities depending on whether the free hydroxyl group was at the C1 or C6 position. The C1-OH (hemiacetal) analogues enhanced growth inhibition in MDA-MB-231 human breast cancer cells and suppressed expression of MUC1, which are attractive properties for an anticancer agent. By contrast, C6-OH analogues supported high metabolic flux into the sialic acid pathway with negligible growth inhibition or toxicity, which are desirable properties for glycan labeling in healthy cells. Importantly, these SAR were general, applying to other hexosamines ( e.g., GlcNAc) and non-natural sugar "scaffolds" ( e.g., ManNLev). From a practical standpoint, the ability to separate toxicity from flux will facilitate the use of MOE analogues for cancer treatment and glycomics applications, respectively. Mechanistically, these findings overturn the premise that the bioactivities of SCFA-monosaccharide hybrid molecules result from their hydrolysis products ( e.g., n-butyrate, which acts as a histone deacetylase inhibitor, and ManNAc, which activates sialic acid biosynthesis); instead the SAR establish that inherent properties of partially acylated hexosamines supersede the cellular responses supported by either the acyl or monosaccharide moieties.