Identification of Molecular Targets of Dietary Grape-Mediated Chemoprevention of Ultraviolet B Skin Carcinogenesis: A Comparative Quantitative Proteomics Analysis

Abstract

We recently showed that dietary grape powder (GP) imparts considerable protection against ultraviolet B (UVB)-mediated skin carcinogenesis in SKH-1 mice. To determine molecular mechanisms of this response, we employed tandem mass tag (TMT) quantitative global proteomics approach on skin tumors from mice exposed to 180 mJ/cm2 UVB twice per week and fed control or 5% GP diet. We found 2629 proteins modulated by GP feeding, with 34 identified using stringent cutoffs (false discovery rate (FDR) q-value ≤ 0.1, fold change ≥ 1.2, p-value ≤ 0.05, ≥ 3 unique peptides). Ingenuity Pathway Analysis helped identify seven proteins involved in protein ubiquitination, including the deubiquitinase UCHL5 and 6 subunits of the 20S proteasome (PSMA1,3,4,6 and PSMB4,7). A second data set without the FDR q-value identified 239 modulated proteins, seven of which are involved in protein ubiquitination. Further, 14 proteins involved in acute phase response signaling were modulated >1.5-fold, including acute phase proteins APCS, FGA, FGB, HP, HPX, and RBP1. Evaluation of upstream regulators found inhibition of ERK1/2 phosphorylation and NF-κB p65, and an increase in IκBα in GP-treated tumors. Overall, our data suggested that GP consumption may mitigate tumorigenesis by enhancing protein ubiquitination and degradation caused by oxidative stress, and manipulates an otherwise tumor-promoting anti-inflammatory environment.

Protective Effects of Dietary Grape on UVB-Mediated Cutaneous Damages and Skin Tumorigenesis in SKH-1 Mice

“…Interestingly, several grape chemopreventive agents are known to affect multiple signaling molecules related to tumor angiogenesis and metastasis [ 36 ]. Previously, employing tandem mass tagging LC–MS/MS in tumor samples from our female model of UVB-induced carcinogenesis, we demonstrated that GP attenuates the chronic pro-inflammatory environment in skin tumors [ 37 ]. However, Thomas-Ahner et al demonstrated that not only do male SKH-1 mice develop more histologically advanced tumors than females, but the two sexes have different amounts of DNA damage and inflammation [ 31 ].…”

“…Additionally, in our previous proteomics study evaluating the anti-tumorigenic effect of dietary grape in female SKH-1 tumors, we found that acute phase response (APR) signaling was abated with the consumption of GP. Upon evaluation of upstream regulators of APR in the female mice, including ERK1/2 and NF-κB, we found that anti-inflammatory effects of GP were associated with modulation in these pathways leading to inhibition of tumor growth [ 37 ]. Therefore, we performed immunoblot analysis of phosphorylated and total p38 and ERK1/2 to elucidate if GP modulates MAPK pathway during protection from UVB-mediated skin tumorigenesis.…”

Novel insights into plasma biomarker candidates in patients with chronic mountain sickness based on proteomics

“…For protein quantification, a median was introduced as the protein ratio type to demonstrate the reproducibility of the replicates, and then the ratios for each protein were normalized using log2. Based on previous studies [ 19 , 20 ], the fold change (FC) (FC > 1.2 or FC < 0.83) cutoff was used to identify DEPs with a global false discovery rate (FDR) of less than 5% in the present study. All mass spectrometry proteomics data were uploaded to proteomics database ProteomeXchange under the Acc.…”

Comprehensive Profiling of Proteome and Ubiquitome Changes in Human Lens Epithelial Cell Line after Ultraviolet-B Irradiation

“… 2 , 7 UVB exposure may destroy the oxidation pathway, generate ROS, and cause multiple morphologic and functional changes in LECs, including increased proteolysis, DNA damage, altered cell cycle, etc. 8 Recently, UVB-induced oxidative damage was found to cause accumulation of ubiquitinated proteins, 9 which prompted us to explore the potential pathogenesis of ARC.…”

“…Previous studies have shown that ultraviolet-B (UVB) irradiation might be a cataractogenic factor, since lens epithelial cells (LECs) are target cells of UVB damage, and the energy of UVB is substantially absorbed to injure the lens. , UVB exposure may destroy the oxidation pathway, generate ROS, and cause multiple morphologic and functional changes in LECs, including increased proteolysis, DNA damage, altered cell cycle, etc . Recently, UVB-induced oxidative damage was found to cause accumulation of ubiquitinated proteins, which prompted us to explore the potential pathogenesis of ARC.…”