scholarly journals The p53/miR-34a/SIRT1 Positive Feedback Loop in Quercetin-Induced Apoptosis

2015 ◽  
Vol 35 (6) ◽  
pp. 2192-2202 ◽  
Author(s):  
Guohua Lou ◽  
Yanning Liu ◽  
Shanshan Wu ◽  
Jihua Xue ◽  
Fan Yang ◽  
...  

Background: The anti-tumor effects of quercetin have been reported, but the underlying molecular mechanisms remain to be elucidated. The aim of present study was to explore the role of miRNA in the anticancer effects of quercetin. Methods: The differential miRNAs expression between the HepG2 and Huh7 cells treated by quercetin were detected by microarray. The xCELLigence, Flow cytometry, RT-PCR and Western blot were used to analyze the cell proliferation, cell apoptosis, cell cycle arrest, anti-tumor genes, and protein expression. Results: miR-34a was up-regulated in HepG2 cells treated by quercetin exhibiting wild-type p53. When inhibiting the miR-34a, the sensitivity of the cells to quercetin decreased and the expression of the SIRT1 was up-regulated, but the acetylation of p53 and the expression of some genes related to p53 down-regulated. Conclusion: miR-34a plays an important role in the anti-tumor effects of querctin in HCC, miR-34a may be a tiemolecule between the p53 and SIRT1 and is composed of a p53/miR-34a/SIRT1 signal feedback loop, which could enhance apoptosis signal and significantly promote cell apoptosis.

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Ju-Huei Chien ◽  
Shan-Chih Lee ◽  
Kai-Fu Chang ◽  
Xiao-Fan Huang ◽  
Yi-Ting Chen ◽  
...  

Pogostemon cablin (PCa), an herb used in traditional Chinese medicine, is routinely used in the amelioration of different types of gastrointestinal discomfort. However, the mechanisms underlying the cancer suppression activity of PCa in colorectal cancer (CRC) cells have yet to be clarified. The aim of this study was to investigate the anticancer effects of PCa, specifically the induction of apoptosis in CRC cells. The growth inhibition curve of CRC cells following exposure to PCa was detected by an MTT assay. Moreover, PCa combined with 5-FU revealed a synergic effect of decreased cell viability. PCa inhibited cell proliferation and induced cell cycle arrest at the G0/G1 phase and cell apoptosis through regulation of associated protein expression. An in vivo study showed that PCa suppressed the growth of CRC via induction of cell apoptosis with no significant change in body weight or organ histology. Our results demonstrated that PCa inhibits the growth of CRC cells and induces apoptosis in vitro and in vivo, which suggests the potential applicability of PCa as an anticancer agent.


Author(s):  
Kanchana Suksri ◽  
Namoiy Semprasert ◽  
Mutita Junking ◽  
Suchanoot Kutpruek ◽  
Thawornchai Limjindaporn ◽  
...  

Long-term medication with dexamethasone (a synthetic glucocorticoid (GC) drug) results in hyperglycemia, or steroid-induced diabetes. Although recent studies revealed dexamethasone directly induces pancreatic β-cell apoptosis, its molecular mechanisms remain unclear. In our initial analysis of mRNA transcripts, we discovered the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) pathway may be involved in dexamethasone-induced pancreatic β-cell apoptosis. In the present study, a mechanism of dexamethasone-induced pancreatic β-cell apoptosis through the TRAIL pathway was investigated in cultured cells and isolated mouse islets. INS-1 cells were cultured with and without dexamethasone in the presence or absence of a glucocorticoid receptor (GR) inhibitor, RU486. We found that dexamethasone induced pancreatic β-cell apoptosis in association with the upregulation of TRAIL mRNA and protein expression. Moreover, dexamethasone upregulated the TRAIL death receptor (DR5) protein but suppressed the decoy receptor (DcR1) protein. Similar findings were observed in mouse isolated islets: dexamethasone increased TRAIL and DR5 compared to that of control mice. Furthermore, dexamethasone stimulated pro-apoptotic signaling including superoxide production, caspase-8, -9, and -3 activities, NF-B, and Bax, but repressed the anti-apoptotic protein, Bcl-2. All these effects were inhibited by the GR-inhibitor, RU486. Furthermore, knock down DR5 decreased dexamethasone-induced caspase 3 activity. Caspase-8 and caspase-9 inhibitors protected pancreatic β-cells from dexamethasone-induced apoptosis. Taken together, dexamethasone induced pancreatic β-cell apoptosis by binding to the GR and inducing DR5 and TRAIL pathway.


2018 ◽  
Vol 51 (5) ◽  
pp. 2185-2197 ◽  
Author(s):  
Lili Men ◽  
Juan Sun ◽  
Decheng Ren

Background/Aims: VCP-interacting membrane selenoprotein (VIMP), an ER resident selenoprotein, is highly expressed in β-cells, however, the role of VIMP in β-cells has not been characterized. In this study, we studied the relationship between VIMP deficiency and β-cell survival in MIN6 insulinoma cells. Methods: To determine the role of VIMP in β-cells, lentiviral VIMP shRNAs were used to knock down (KD) expression of VIMP in MIN6 cells. Cell death was quantified by propidium iodide (PI) staining followed by flow cytometric analyses using a FACS Caliber and FlowJo software. Cell apoptosis and proliferation were determined by TUNEL assay and Ki67 staining, respectively. Cell cycle was analyzed after PI staining. Results: The results show that 1) VIMP suppression induces β-cell apoptosis, which is associated with a decrease in Bcl-xL, and the β-cell apoptosis induced by VIMP suppression can be inhibited by overexpression of Bcl-xL; 2) VIMP knockdown (KD) decreases cell proliferation and G1 cell cycle arrest by accumulating p27 and decreasing E2F1; 3) VIMP KD suppresses unfolded protein response (UPR) activation by regulating the IRE1α and PERK pathways; 4) VIMP KD increases insulin secretion. Conclusion: These results suggest that VIMP may function as a novel regulator to modulate β-cell survival, proliferation, cell cycle, UPR and insulin secretion in MIN6 cells.


Biomedicines ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1086
Author(s):  
Vasiliki Zoi ◽  
Vasiliki Galani ◽  
Georgios D. Lianos ◽  
Spyridon Voulgaris ◽  
Athanasios P. Kyritsis ◽  
...  

Curcumin is a polyphenol extracted from the rhizomes of the turmeric plant, Curcuma longa which has anti-inflammatory, and anticancer properties. Chronic inflammation is associated with the development of cancer. Curcumin acts on the regulation of various immune modulators, including cytokines, cyclooxygenase-2 (COX-2), and reactive oxygen species (ROS), which partly explains its anticancer effects. It also takes part in the downregulation of growth factors, protein kinases, oncogenic molecules and various signaling pathways, such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), c-Jun N-terminal kinase (JNK) and signal transducer and activator of transcription 3 (STAT3) signaling. Clinical trials of curcumin have been completed or are ongoing for various types of cancer. This review presents the molecular mechanisms of curcumin in different types of cancer and the evidence from the most recent clinical trials.


Toxins ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 43 ◽  
Author(s):  
Junhua Yang ◽  
Wenbo Guo ◽  
Jianhua Wang ◽  
Xianli Yang ◽  
Zhiqi Zhang ◽  
...  

T-2 toxin, as a highly toxic mycotoxin to humans and animals, induces oxidative stress and apoptosis in various cells and tissues. Apoptosis and mitochondrial fusion/fission are two tightly interconnected processes that are crucial for maintaining physiological homeostasis. However, the role of mitochondrial fusion/fission in apoptosis of T-2 toxin remains unknown. Hence, we aimed to explore the putative role of mitochondrial fusion/fission on T-2 toxin induced apoptosis in normal human liver (HL-7702) cells. T-2 toxin treatment (0, 0.1, 1.0, or 10 μg/L) for 24 h caused decreased cell viability and ATP concentration and increased production of (ROS), as seen by a loss of mitochondrial membrane potential (∆Ψm) and increase in mitochondrial fragmentation. Subsequently, the mitochondrial dynamic imbalance was activated, evidenced by a dose-dependent decrease and increase in the protein expression of mitochondrial fusion (OPA1, Mfn1, and Mfn2) and fission (Drp1 and Fis1), respectively. Furthermore, the T-2 toxin promoted the release of cytochrome c from mitochondria to cytoplasm and induced cell apoptosis triggered by upregulation of Bax and Bax/Bcl-2 ratios, and further activated the caspase pathways. Taken together, these results indicate that altered mitochondrial dynamics induced by oxidative stress with T-2 toxin exposure likely contribute to mitochondrial injury and HL-7702 cell apoptosis.


2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Hang Gao ◽  
Siyue Lou ◽  
Huanwu Hong ◽  
Qiufu Ge ◽  
Huajun Zhao

Acute T lymphocytic leukemia (T-ALL) is an aggressive hematologic resulting from the malignant transformation of T-cell progenitors. Drug resistance and relapse are major difficulties in the treatment of T-ALL. Here, we report the antitumor potency of NL-101, a compound that combines the nitrogen mustard group of bendamustine with the hydroxamic acid group of vorinostat. We found NL-101 exhibited efficient antiproliferative activity in T-ALL cell lines (IC50 1.59–1.89 μM), accompanied by cell cycle arrest and apoptosis, as evidenced by the increased expression of Cyclin E1, CDK2, and CDK4 proteins and cleavage of PARP. In addition, this bendamustine-derived drug showed both a HDACi effect as demonstrated by histone hyperacetylation and p21 transcription and a DNA-damaging effect as shown by an increase in γ-H2AX. Intriguingly, we found that NL-101-induced autophagy in T-ALL cells through inhibiting Akt-mTOR signaling pathway, as indicated by an increase in LC3-I to LC3-II conversion and decrease of p62. Furthermore, inhibition of autophagy by 3-methyladenine increased apoptotic cell death by NL-101, suggesting a prosurvival role of autophagy. In summary, our finding provides rationale for investigation of NL-101 as a DNA/HDAC dual targeting drug in T-ALL, either as a single agent or in combination with autophagy inhibitors.


2020 ◽  
Vol 48 (01) ◽  
pp. 161-182 ◽  
Author(s):  
Jihan Huang ◽  
Wei Guo ◽  
Fan Cheung ◽  
Hor-Yue Tan ◽  
Ning Wang ◽  
...  

Unlike Western medicines with single-target, the traditional Chinese medicines (TCM) always exhibit diverse curative effects against multiple diseases through its “multi-components” and “multi-targets” manifestations. However, discovery and identification of the major therapeutic diseases and the underlying molecular mechanisms of TCM remain to be challenged. In the current study, we, for the first time, applied an integrated strategy by combining network pharmacology with experimental evaluation, for exploration and demonstration of the therapeutic potentials and the underlying possible mechanisms of a classic TCM formula, Huanglian Jiedu decoction (HLJDD). First, the herb–compound, compound–protein, protein–pathway, and gene–disease networks were constructed to predict the major therapeutic diseases of HLJDD and explore the underlying molecular mechanisms. Network pharmacology analysis showed the top one predicted disease of HLJDD treatment was cancer, especially hepatocellular carcinoma (HCC) and inflammation-related genes played an important role in the treatment of HLJDD on cancer. Next, based on the prediction by network pharmacology analysis, both in vitro HCC cell and in vivo orthotopic HCC implantation mouse models were established to validate the curative role of HLJDD. HLJDD exerted its antitumor activity on HCC in vitro, as demonstrated by impaired cell proliferation and colony formation abilities, induced apoptosis and cell cycle arrest, as well as inhibited migratory and invasive properties of HCC cells. The orthotopic HCC implantation mouse model further demonstrated the remarkable antitumour effects of HLJDD on HCC in vivo. In conclusion, our study demonstrated the effectiveness of integrating network pharmacology with experimental study for discovery and identification of the major therapeutic diseases and the underlying molecular mechanisms of TCM.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Qingqiang Xu ◽  
Wenwen Shi ◽  
Pan Lv ◽  
Wenqi Meng ◽  
Guanchao Mao ◽  
...  

AbstractAflatoxin B1 (AFB1) is a potent hepatocarcinogen in humans and exposure to AFB1 is known to cause both acute and chronic hepatocellular injury. As the liver is known to be the main target organ of aflatoxin, it is important to identify the key molecules that participate in AFB1-induced hepatotoxicity and to investigate their underlying mechanisms. In this study, the critical role of caveolin-1 in AFB1-induced hepatic cell apoptosis was examined. We found a decrease in cell viability and an increase in oxidation and apoptosis in human hepatocyte L02 cells after AFB1 exposure. In addition, the intracellular expression of caveolin-1 was increased in response to AFB1 treatment. Downregulation of caveolin-1 significantly alleviated AFB1-induced apoptosis and decreased cell viability, whereas overexpression of caveolin-1 reversed these effects. Further functional analysis showed that caveolin-1 participates in AFB1-induced oxidative stress through its interaction with Nrf2, leading to the downregulation of cellular antioxidant enzymes and the promotion of oxidative stress-induced apoptosis. In addition, caveolin-1 was found to regulate AFB1-induced autophagy. This finding was supported by the effect that caveolin-1 deficiency promoted autophagy after AFB1 treatment, leading to the inhibition of apoptosis, whereas overexpression of caveolin-1 inhibited autophagy and accelerated apoptosis. Interestingly, further investigation showed that caveolin-1 participates in AFB1-induced autophagy by regulating the EGFR/PI3K-AKT/mTOR signaling pathway. Taken together, our data reveal that caveolin-1 plays a crucial role in AFB1-induced hepatic cell apoptosis via the regulation of oxidation and autophagy, which provides a potential target for the development of novel treatments to combat AFB1 hepatotoxicity.


2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
Jian Gao ◽  
Xia Chen ◽  
Qing Gu ◽  
Xiaoxiao Liu ◽  
Xun Xu

Pericyte loss is an early characteristic change in diabetic retinopathy, but its precise molecular mechanisms have not been elucidated. This study investigated the role of SENP1 in pericyte loss in diabetic retinopathy. We demonstrated that a high concentration of glucose inhibited the expression of the Sentrin/SUMO-specific protease 1 (SENP1), which resulted in an increase in DBC1 sumoylation in bovine retinal pericytes (BRPCs). Furthermore, SENP1 overexpression attenuated hyperemia-induced apoptosis of BPRCs, and SENP1 knockdown aggravated this effect. We also provide evidence that DBC1 sumoylation/desumoylation is involved in the SENP1-regulated apoptosis of BRPCs under high glucose conditions. Understanding the role of SENP1 in the pathogenesis of high glucose induced pericyte loss could help elucidate important targets for future pharmacological interventions.


2019 ◽  
Vol 400 (2) ◽  
pp. 237-246 ◽  
Author(s):  
Peng Sun ◽  
Dan Zhang ◽  
Haiping Huang ◽  
Yafeng Yu ◽  
Zhendong Yang ◽  
...  

Abstract This study aimed to investigate the role of miRNA-1225-5p (miR-1225) in laryngeal carcinoma (LC). We found that the expression of miR-1225 was suppressed in human LC samples, while CDC14B (cell division cycle 14B) expression was reinforced in comparison with surrounding normal tissues. We also demonstrated that enhanced expression of miR-1225 impaired the proliferation and survival of LC cells, and resulted in G1/S cell cycle arrest. In contrast, reduced expression of miR-1225 promoted cell survival. Moreover, miR-1225 resulted in G1/S cell cycle arrest and enhanced cell death. Further, miR-1225 targets CDC14B 3′-UTR and recovery of CDC14B expression counteracted the suppressive influence of miR-1225 on LC cells. Thus, these findings offer insight into the biological and molecular mechanisms behind the development of LC.


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