Necroptosis increases with age and is reduced by dietary restriction
AGING CELL
Authors: Deepa, Sathyaseelan S.; Unnikrishnan, Archana; Matyi, Stephanie; Hadad, Niran; Richardson, Arlan
Abstract
Necroptosis is a newly identified programmed cell death pathway that is highly proinflammatory due to the release of cellular components that promote inflammation. To determine whether necroptosis might play a role in inflammaging, we studied the effect of age and dietary restriction (DR) on necroptosis in the epididymal white adipose tissue (eWAT), a major source of proinflammatory cytokines. Phosphorylated MLKL and RIPK3, markers of necroptosis, were increased 2.7- and 1.9-fold, respectively, in eWAT of old mice compared to adult mice, and DR reduced P-MLKL and P-RIPK3 to levels similar to adult mice. An increase in the expression of RIPK1 (1.6-fold) and MLKL (2.7- fold), not RIPK3, was also observed in eWAT of old mice, which was reduced by DR in old mice. The increase in necroptosis was paralleled by an increase in 14 inflammatory cytokines, including the pro-inflammatory cytokines IL-6 (3.9-fold), TNF-alpha (4.7-fold), and IL-1 beta (5.1-fold)], and 11 chemokines in old mice. DR attenuated the expression of IL-6, TNF-alpha, and IL-1 beta as well as 85% of the other cytokines/chemokines induced with age. In contrast, inguinal WAT (iWAT), which is less inflammatory, did not show any significant increase with age in the levels of PMLKL and MLKL or inflammatory cytokines/chemokines. Because the changes in biomarkers of necroptosis in eWAT with age and DR paralleled the changes in the expression of pro-inflammatory cytokines, our data support the possibility that necroptosis might play a role in increased chronic inflammation observed with age.
FOLFOX treatment response prediction in metastatic or recurrent colorectal cancer patients via machine learning algorithms
CANCER MEDICINE
Authors: Lu, Wei; Fu, Dongliang; Kong, Xiangxing; Huang, Zhiheng; Hwang, Maxwell; Zhu, Yingshuang; Chen, Liubo; Jiang, Kai; Li, Xinlin; Wu, Yihua; Li, Jun; Yuan, Ying; Ding, Kefeng
Abstract
Early identification of metastatic or recurrent colorectal cancer (CRC) patients who will be sensitive to FOLFOX (5-FU, leucovorin and oxaliplatin) therapy is very important. We performed microarray meta-analysis to identify differentially expressed genes (DEGs) between FOLFOX responders and nonresponders in metastatic or recurrent CRC patients, and found that the expression levels of WASHC4, HELZ, ERN1, RPS6KB1, and APPBP2 were downregulated, while the expression levels of IRF7, EML3, LYPLA2, DRAP1, RNH1, PKP3, TSPAN17, LSS, MLKL, PPP1R7, GCDH, C19ORF24, and CCDC124 were upregulated in FOLFOX responders compared with nonresponders. Subsequent functional annotation showed that DEGs were significantly enriched in autophagy, ErbB signaling pathway, mitophagy, endocytosis, FoxO signaling pathway, apoptosis, and antifolate resistance pathways. Based on those candidate genes, several machine learning algorithms were applied to the training set, then performances of models were assessed via the cross validation method. Candidate models with the best tuning parameters were applied to the test set and the final model showed satisfactory performance. In addition, we also reported that MLKL and CCDC124 gene expression were independent prognostic factors for metastatic CRC patients undergoing FOLFOX therapy.