scholarly journals Pharmacologic Ascorbate Primes Pancreatic Cancer Cells for Death by Rewiring Cellular Energetics and Inducing DNA Damage

2019 ◽  
Vol 17 (10) ◽  
pp. 2102-2114 ◽  
Author(s):  
Visarut Buranasudja ◽  
Claire M. Doskey ◽  
Adrienne R. Gibson ◽  
Brett A. Wagner ◽  
Juan Du ◽  
...  
Author(s):  
Md Akram Hossain ◽  
Yunfeng Lin ◽  
Garrett Driscoll ◽  
Jia Li ◽  
Anne McMahon ◽  
...  

The maintenance of genome integrity and fidelity is vital for the proper function and survival of all organisms. Recent studies have revealed that APE2 is required to activate an ATR-Chk1 DNA damage response (DDR) pathway in response to oxidative stress and a defined DNA single-strand break (SSB) in Xenopus laevis egg extracts. However, it remains unclear whether APE2 is a general regulator of the DDR pathway in mammalian cells. Here, we provide evidence using human pancreatic cancer cells that APE2 is essential for ATR DDR pathway activation in response to different stressful conditions including oxidative stress, DNA replication stress, and DNA double-strand breaks. Fluorescence microscopy analysis shows that APE2-knockdown (KD) leads to enhanced γH2AX foci and increased micronuclei formation. In addition, we identified a small molecule compound Celastrol as an APE2 inhibitor that specifically compromises the binding of APE2 but not RPA to ssDNA and 3′-5′ exonuclease activity of APE2 but not APE1. The impairment of ATR-Chk1 DDR pathway by Celastrol in Xenopus egg extracts and human pancreatic cancer cells highlights the physiological significance of Celastrol in the regulation of APE2 functionalities in genome integrity. Notably, cell viability assays demonstrate that APE2-KD or Celastrol sensitizes pancreatic cancer cells to chemotherapy drugs. Overall, we propose APE2 as a general regulator for the DDR pathway in genome integrity maintenance.


Cancers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1460 ◽  
Author(s):  
Liang Yan ◽  
Priyank Raj ◽  
Wantong Yao ◽  
Haoqiang Ying

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive and lethal cancers, with a five-year survival rate of around 5% to 8%. To date, very few available drugs have been successfully used to treat PDAC due to the poor understanding of the tumor-specific features. One of the hallmarks of pancreatic cancer cells is the deregulated cellular energetics characterized by the “Warburg effect”. It has been known for decades that cancer cells have a dramatically increased glycolytic flux even in the presence of oxygen and normal mitochondrial function. Glycolytic flux is the central carbon metabolism process in all cells, which not only produces adenosine triphosphate (ATP) but also provides biomass for anabolic processes that support cell proliferation. Expression levels of glucose transporters and rate-limiting enzymes regulate the rate of glycolytic flux. Intermediates that branch out from glycolysis are responsible for redox homeostasis, glycosylation, and biosynthesis. Beyond enhanced glycolytic flux, pancreatic cancer cells activate nutrient salvage pathways, which includes autophagy and micropinocytosis, from which the generated sugars, amino acids, and fatty acids are used to buffer the stresses induced by nutrient deprivation. Further, PDAC is characterized by extensive metabolic crosstalk between tumor cells and cells in the tumor microenvironment (TME). In this review, we will give an overview on recent progresses made in understanding glucose metabolism-related deregulations in PDAC.


2015 ◽  
Vol 369 (1) ◽  
pp. 192-201 ◽  
Author(s):  
Zheng Wang ◽  
Song-Tao Lai ◽  
Ning-Yi Ma ◽  
Yun Deng ◽  
Yong Liu ◽  
...  

2021 ◽  
Vol 233 ◽  
pp. 02023
Author(s):  
Chengyong Zhang ◽  
Tingting Yang ◽  
Xiaoting Chen ◽  
Jiexuan Xu ◽  
Danlu Liang ◽  
...  

Pancreatic cancer is a kind of malignant tumor with high mortality rate. Early operation and late chemoradiotherapy are the treatment criteria, but the prognosis is still poor. Berberine, an alkaloid compound present in many herbal plants, is capable of inducing oxidative DNA damage and downregulating homologous recombination repair (HRR) in cancer cells. Poly (ADP ribose) polymerase-1 (PARP-1) is a sensor of DNA damage with key roles in DNA repair. In this study, we demonstrated that berberine and PARP inhibitor olaparib have a synthetic lethal effect on pancreatic cancer cells. The expression level of RAD51 were reduced by berberine. Correspondingly, PARP became hyperactivated in response to berberine treatment. When berberine is combined with olaparib, the expression of Rad51 and Parp are inhibited. The combination of berberine and olaparib synergistically inhibit cell activity and induce cell apoptosis. In addition, the synergistic effect of berberine and olaparib can be reversed by apoptosis inhibitor and necrosis inhibitor. Together, the results indicate that berberine combined with olaparib have a synthetic lethal effect on pancreatic cancer cells.


2012 ◽  
Author(s):  
Shruti Lal ◽  
Vikram Bhattacharjee ◽  
Timothy Yen ◽  
Richard A. Burkhart ◽  
Danielle M. Pineda ◽  
...  

2010 ◽  
Vol 49 ◽  
pp. S58-S59
Author(s):  
Juan Du ◽  
Amanda Kalen ◽  
Zita Sibenaller ◽  
Prabhat Goswami ◽  
Joseph Cullen

PLoS ONE ◽  
2017 ◽  
Vol 12 (7) ◽  
pp. e0180940 ◽  
Author(s):  
Patrick Naumann ◽  
Jakob Liermann ◽  
Franco Fortunato ◽  
Thomas E. Schmid ◽  
Klaus-Josef Weber ◽  
...  

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