The pressing need for SARS-CoV-2 controls has led to a reassessment of strategies to
identify and develop natural product inhibitors of zoonotic, highly virulent, and
rapidly emerging viruses. This review article addresses how contemporary approaches
involving computational chemistry, natural product (NP) and protein databases, and mass
spectrometry (MS) derived target–ligand interaction analysis can be utilized to
expedite the interrogation of NP structures while minimizing the time and expense of
extraction, purification, and screening in BioSafety Laboratories (BSL)3 laboratories.
The unparalleled structural diversity and complexity of NPs is an extraordinary resource
for the discovery and development of broad-spectrum inhibitors of viral genera,
including
Betacoronavirus
, which contains MERS, SARS, SARS-CoV-2, and
the common cold. There are two key technological advances that have created unique
opportunities for the identification of NP prototypes with greater efficiency: (1) the
application of structural databases for NPs and target proteins and (2) the application
of modern MS techniques to assess protein–ligand interactions directly from NP
extracts. These approaches, developed over years, now allow for the identification and
isolation of unique antiviral ligands without the immediate need for BSL3 facilities.
Overall, the goal is to improve the success rate of NP-based screening by focusing
resources on source materials with a higher likelihood of success, while simultaneously
providing opportunities for the discovery of novel ligands to selectively target
proteins involved in viral infection.
Highlights
Nutrition associated glycoxidation promotes aggressive prostate tumor growth.
AGEs, the final product of glycoxidation were a key pro-tumorigenic effector.
Dietary-AGE mediated effects were dependent upon stromal RAGE expression.
AGE-RAGE signaling caused a regulatory program of activated stroma & CAF activation.
Dietary-AGE effects were reproduced using
in vivo, ex vivo
and
in vitro
models.
Objectives
The literature regarding the role of advanced glycation end products (AGEs) on tumor biology has shown only moderate promise reflected by increases in cell growth, migration and invasion in vitro which is not supported by increased tumor growth in vivo14-16– A caveat to these studies is that they are centered upon a single AGE peptide and a subsequent assessment of their molecular effects on tumor epithelial cells. The objective is to show that by feeding mice a high AGE diet we can recapitulate a microenvironment comprising of a wide spectrum of AGEs which can influence neoplastic growth.
Methods
We recapitulated a dietary-AGE induced microenvironment in syngeneic xenograft and spontaneous breast and prostate mouse cancer models and the effects on tumor growth assessed. The mechanistic consequences of dietary-AGEs on the tumor microenvironment were further defined using mouse and human primary and immortalized two-compartment co-culture ex vivo culture models.
Results
Dietary-AGE consumption in breast and prostate tumor models significantly accelerated tumor growth by functioning as ligand to the transmembrane receptor for AGE (RAGE). Our studies demonstrate that AGEs promote neoplastic growth by functioning as ligand to RAGE expressed in the tumor stroma not the tumor epithelial cells. Dietary-AGE activation of RAGE in both breast and prostate tumors caused a regulatory program of ‘activated fibroblasts’ defined by increased expression of cancer associated fibroblast markers, NFkB and MYC upregulation, and pro-tumorigenic paracrine secretion. Complementary to this, our published studies show that high intake of dietary AGE after BCa diagnosis increases risk of mortality in postmenopausal women.
Conclusions
These data demonstrate, for the first time, the oncogenic potential of dietary-AGEs in promoting neoplastic growth. This lays the foundation for strategic changes aimed at reducing cancer incidence and mortality as pharmacological, educational and/or interventional strategies aimed at reducing the dietary-AGE accumulation pool may one day be viewed as universal cancer preventative and/or therapeutic initiatives especially when combined with existing therapies.
Funding Sources
David P. Turner was supported by grants from the NIH/NCI, R21 CA194469 and U54 CA21096..
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