scholarly journals Production of ROS by Gallic Acid Activates KDM2A to Reduce rRNA Transcription

Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2266
Author(s):  
Yuji Tanaka ◽  
Hideru Obinata ◽  
Akimitsu Konishi ◽  
Noriyuki Yamagiwa ◽  
Makoto Tsuneoka

Metformin, which is suggested to have anti-cancer effects, activates KDM2A to reduce rRNA transcription and proliferation of cancer cells. Thus, the specific activation of KDM2A may be applicable to the treatment of cancers. In this study, we screened a food-additive compound library to identify compounds that control cell proliferation. We found that gallic acid activated KDM2A to reduce rRNA transcription and cell proliferation in breast cancer MCF-7 cells. Gallic acid accelerated ROS production and activated AMPK. When ROS production or AMPK activity was inhibited, gallic acid did not activate KDM2A. These results suggest that both ROS production and AMPK activation are required for activation of KDM2A by gallic acid. Gallic acid did not reduce the succinate level, which was required for KDM2A activation by metformin. Metformin did not elevate ROS production. These results suggest that the activation of KDM2A by gallic acid includes mechanisms distinct from those by metformin. Therefore, signals from multiple intracellular conditions converge in KDM2A to control rRNA transcription. Gallic acid did not induce KDM2A-dependent anti-proliferation activity in non-tumorigenic MCF10A cells. These results suggest that the mechanism of KDM2A activation by gallic acid may be applicable to the treatment of breast cancers.

Biomolecules ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 30
Author(s):  
Yuji Tanaka ◽  
Makoto Tsuneoka

We previously reported that lysine-demethylase 2A (KDM2A), a Jumonji-C histone demethylase, is activated by gallic acid to reduce H3K36me2 levels in the rRNA gene promoter and consequently inhibit rRNA transcription and cell proliferation in the breast cancer cell line MCF-7. Gallic acid activates AMP-activated protein kinase (AMPK) and increases reactive oxygen species (ROS) production to activate KDM2A. Esters of gallic acid, propyl gallate (PG) and epigallocatechin gallate (EGCG), and other chemicals, reduce cancer cell proliferation. However, whether these compounds activate KDM2A has yet to be tested. In this study, we found that PG and EGCG decreased rRNA transcription and cell proliferation through KDM2A in MCF-7 cells. The activation of both AMPK and ROS production by PG or EGCG was required to activate KDM2A. Of note, while the elevation of ROS production by PG or EGCG was limited in time, it was sufficient to activate KDM2A. Importantly, the inhibition of rRNA transcription and cell proliferation by gallic acid, PG, or EGCG was specifically observed in MCF-7 cells, whereas it was not observed in non-tumorigenic MCF10A cells. Altogether, these results suggest that the derivatization of gallic acid may be used to obtain new compounds with anti-cancer activity.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yuji Tanaka ◽  
Akimitsu Konishi ◽  
Hideru Obinata ◽  
Makoto Tsuneoka

AbstractMetformin is used to treat type 2 diabetes. Metformin activates AMP-activated kinase (AMPK), which may contribute to the action of metformin. Metformin also shows anti-proliferation activity. However, the mechanism is remained unknown. We found that treatment of MCF-7 cells with metformin induced the demethylase activity of KDM2A in the rDNA promoter, which resulted in reductions of rRNA transcription and cell proliferation. AMPK activity was required for activation of KDM2A by metformin. Because demethylase activities of JmjC-type enzymes require a side reaction converting α-ketoglutarate to succinate, these organic acids may affect their demethylase activities. We found that metformin did not induce KDM2A demethylase activity in conditions of a reduced level of α-ketoglutarate. A four-hour treatment of metformin specifically reduced succinate, and the replenishment of succinate inhibited the activation of KDM2A by metformin, but did not inhibit the activation of AMPK. Metformin reduced succinate even in the conditions suppressing AMPK activity. These results indicate that metformin activates AMPK and reduces the intracellular succinate level, both of which are required for the activation of KDM2A to reduce rRNA transcription. The results presented here uncover a novel factor of metformin actions, reduction of the intracellular succinate, which contributes to the anti-proliferation activity of metformin.


2021 ◽  
Vol 22 (6) ◽  
pp. 2915
Author(s):  
Manuela Cipolletti ◽  
Stefania Bartoloni ◽  
Claudia Busonero ◽  
Martina Parente ◽  
Stefano Leone ◽  
...  

17β-estradiol (E2) exerts its physiological effects through the estrogen receptor α (i.e., ERα). The E2:ERα signaling allows the regulation of cell proliferation. Indeed, E2 sustains the progression of ERα positive (ERα+) breast cancers (BCs). The presence of ERα at the BC diagnosis drives their therapeutic treatment with the endocrine therapy (ET), which restrains BC progression. Nonetheless, many patients develop metastatic BCs (MBC) for which a treatment is not available. Consequently, the actual challenge is to complement the drugs available to fight ERα+ primary and MBC. Here we exploited a novel anti-estrogen discovery platform to identify new Food and Drug Administration (FDA)-approved drugs inhibiting E2:ERα signaling to cell proliferation in cellular models of primary and MBC cells. We report that the anti-fungal drugs clotrimazole (Clo) and fenticonazole (Fenti) induce ERα degradation and prevent ERα transcriptional signaling and proliferation in cells modeling primary and metastatic BC. The anti-proliferative effects of Clo and Fenti occur also in 3D cancer models (i.e., tumor spheroids) and in a synergic manner with the CDK4/CDK6 inhibitors palbociclib and abemaciclib. Therefore, Clo and Fenti behave as “anti-estrogens”-like drugs. Remarkably, the present “anti-estrogen” discovery platform represents a valuable method to rapidly identify bioactive compounds with anti-estrogenic activity.


2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Yanjuan Hou ◽  
Qian Wang ◽  
Baosheng Han ◽  
Yiliang Chen ◽  
Xi Qiao ◽  
...  

AbstractTubulointerstitial inflammation plays a key role in the pathogenesis of diabetic nephropathy (DN). Interleukin-1β (IL-1β) is the key proinflammatory cytokine associated with tubulointerstitial inflammation. The NLRP3 inflammasome regulates IL-1β activation and secretion. Reactive oxygen species (ROS) represents the main mediator of NLRP3 inflammasome activation. We previously reported that CD36, a class B scavenger receptor, mediates ROS production in DN. Here, we determined whether CD36 is involved in NLRP3 inflammasome activation and explored the underlying mechanisms. We observed that high glucose induced-NLRP3 inflammasome activation mediate IL-1β secretion, caspase-1 activation, and apoptosis in HK-2 cells. In addition, the levels of CD36, NLRP3, and IL-1β expression (protein and mRNA) were all significantly increased under high glucose conditions. CD36 knockdown resulted in decreased NLRP3 activation and IL-1β secretion. CD36 knockdown or the addition of MitoTempo significantly inhibited ROS production in HK-2 cells. CD36 overexpression enhanced NLRP3 activation, which was reduced by MitoTempo. High glucose levels induced a change in the metabolism of HK-2 cells from fatty acid oxidation (FAO) to glycolysis, which promoted mitochondrial ROS (mtROS) production after 72 h. CD36 knockdown increased the level of AMP-activated protein kinase (AMPK) activity and mitochondrial FAO, which was accompanied by the inhibition of NLRP3 and IL-1β. The in vivo experimental results indicate that an inhibition of CD36 could protect diabetic db/db mice from tubulointerstitial inflammation and tubular epithelial cell apoptosis. CD36 mediates mtROS production and NLRP3 inflammasome activation in db/db mice. CD36 inhibition upregulated the level of FAO-related enzymes and AMPK activity in db/db mice. These results suggest that NLRP3 inflammasome activation is mediated by CD36 in renal tubular epithelial cells in DN, which suppresses mitochondrial FAO and stimulates mtROS production.


2011 ◽  
Vol 179 (3) ◽  
pp. 1148-1156 ◽  
Author(s):  
Yoshiya Horimoto ◽  
Johan Hartman ◽  
Julie Millour ◽  
Steven Pollock ◽  
Yolanda Olmos ◽  
...  

2014 ◽  
Vol 111 (15) ◽  
pp. 5586-5591 ◽  
Author(s):  
S. J. Streichan ◽  
C. R. Hoerner ◽  
T. Schneidt ◽  
D. Holzer ◽  
L. Hufnagel

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