scholarly journals Perspectives Regarding the Intersections between STAT3 and Oxidative Metabolism in Cancer

Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2202
Author(s):  
Kyung-Soo Chun ◽  
Jeong-Hoon Jang ◽  
Do-Hee Kim

Signal transducer and activator of transcription 3 (STAT3) functions as a major molecular switch that plays an important role in the communication between cytokines and kinases. In this role, it regulates the transcription of genes involved in various biochemical processes, such as proliferation, migration, and metabolism of cancer cells. STAT3 undergoes diverse post-translational modifications, such as the oxidation of cysteine by oxidative stress, the acetylation of lysine, or the phosphorylation of serine/threonine. In particular, the redox modulation of critical cysteine residues present in the DNA-binding domain of STAT3 inhibits its DNA-binding activity, resulting in the inactivation of STAT3-mediated gene expression. Accumulating evidence supports that STAT3 is a key protein that acts as a mediator of metabolism and mitochondrial activity. In this review, we focus on the post-translational modifications of STAT3 by oxidative stress and how the modification of STAT3 regulates cell metabolism, particularly in the metabolic pathways in cancer cells.

2001 ◽  
Vol 280 (5) ◽  
pp. H2094-H2102 ◽  
Author(s):  
B. Chandrasekar ◽  
J. F. Nelson ◽  
J. T. Colston ◽  
G. L. Freeman

The life-prolonging effects of calorie restriction (CR) may be due to reduced damage from cumulative oxidative stress. Our goal was to determine the long-term effects of moderate dietary CR on the myocardial response to reperfusion after a single episode of sublethal ischemia. Male Fisher 344 rats were fed either an ad libitum (AL) or CR (40% less calories) diet. At age 12 mo the animals were anaesthetized and subjected to thoracotomy and a 15-min left-anterior descending coronary artery occlusion. The hearts were reperfused for various periods. GSH and GSSG levels, nuclear factor-κB (NF-κB) DNA binding activity, cytokine, and antioxidant enzyme expression were assessed in the ischemic zones. Sham-operated animals served as controls. Compared with the AL diet, chronic CR limited oxidative stress as seen by rapid recovery in GSH levels in previously ischemic myocardium. CR reduced DNA binding activity of NF-κB. The κB-responsive cytokines interleukin-1β and tumor necrosis factor-α were transiently expressed in the CR group but persisted longer in the AL group. Furthermore, expression of manganese superoxide dismutase, a key antioxidant enzyme, was significantly delayed in the AL group. Collectively these data indicate that CR significantly attenuates myocardial oxidative stress and the postischemic inflammatory response.


2004 ◽  
Vol 377 (1) ◽  
pp. 241-248 ◽  
Author(s):  
Kaoru OTSU ◽  
Yoshitaka IKEDA ◽  
Junichi FUJII

A diet low in copper results in increased levels of MnSOD (manganese superoxide dismutase), a critical antioxidative enzyme conferring protection against oxidative stress, in rat liver mitochondria. The mechanism for this was investigated using cultured HepG2 cells, a human hepatocellular carcinoma-derived line. MnSOD activity increased 5–7-fold during incubation in a medium supplemented with metal-depleted fetal bovine serum, with a corresponding elevation of its mRNA levels. Metal depletion also decreased CuZnSOD and glutathione peroxidase levels to approx. 70–80% of baseline. When zinc ions were added to the medium at micromolar levels, MnSOD accumulation was suppressed; however, copper ions had essentially no effect on MnSOD expression. Since the intracellular redox status was shifted to a more oxidized state by metal depletion, we examined the DNA-binding activity of NF-κB (nuclear factor-κB), an oxidative stress-sensitive transactivating factor that plays a primary role in MnSOD induction. A gel shift assay indicated that the DNA-binding activity of NF-κB was increased in cells maintained in metal-depleted culture, suggesting the involvement of the transactivating function of NF-κB in this induction. This was further supported by the observation that curcumin suppressed both the DNA-binding activity of NF-κB and the induction of MnSOD mRNA in cells cultivated under metal-depleted conditions. These results suggest that the level of zinc, rather than copper, is a critical regulatory factor in MnSOD expression. It is possible that a deficiency of zinc in the low-copper diet may be primarily involved in MnSOD induction.


2016 ◽  
Vol 94 (7) ◽  
pp. 745-751 ◽  
Author(s):  
Nagla A. El-Sherbeeny ◽  
Ghalia M. Attia

Nephrotoxicity is a dose-limiting side effect of cisplatin (CSP). The study investigated the possible protective role of trimetazidine (TMZ) against CSP-induced nephrotoxicity in rats. Rats were divided into four groups; control, TMZ, CSP, and CSP + TMZ. The CSP group showed significant deterioration in kidney function with structural changes in the form of interstitial hemorrhage, glomeruli shrinkage and peritublar capillary congestion, tubular cells vacuolation, pyknosis, shedding and necrosis, and inflammatory cell infiltrates, all indicating renal damage. CSP also caused a significant increase in the lipid peroxidation marker malondialdehyde (MDA) levels, renal nuclear factor kappa B (NF-κB) DNA-binding activity and protein expression, and tumor necrosis factor alpha (TNF-α) and IL-6 levels. Treatment with TMZ before and after CSP injection produced significant improvement of kidney function and histopathology. TMZ treatment also significantly attenuated CSP-induced oxidative stress and suppressed elevated levels of TNF-α and IL-6 and NF-κB expression and its DNA-binding activity caused by CSP administration. TMZ has a protective effect against CSP-induced nephrotoxicity mediated by reduction of oxidative stress and attenuation of CSP-induced inflammation.


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