scholarly journals Anti- and Protumorigenic Effects of PPARγin Lung Cancer Progression: A Double-Edged Sword

PPAR Research ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Howard Li ◽  
Mary C. M. Weiser-Evans ◽  
Raphael Nemenoff

Peroxisome proliferator-activated receptor-γ(PPARγ) is a member of the nuclear receptor superfamily of ligand-activated transcription factors that plays an important role in the control of gene expression linked to a variety of physiological processes, including cancer. Ligands for PPARγinclude naturally occurring fatty acids and the thiazolidinedione class of antidiabetic drugs. Activation of PPARγin a variety of cancer cells leads to inhibition of growth, decreased invasiveness, reduced production of proinflammatory cytokines, and promotion of a more differentiated phenotype. However, systemic activation of PPARγhas been reported to be protumorigenic in somein vitrosystems andin vivomodels. Here, we review the available data that implicate PPARγin lung carcinogenesis and highlight the challenges of targeting PPARγin lung cancer treatments.

2007 ◽  
Vol 28 (2) ◽  
pp. 687-704 ◽  
Author(s):  
Cameron N. Johnstone ◽  
Perry S. Mongroo ◽  
A. Sophie Rich ◽  
Michael Schupp ◽  
Mark J. Bowser ◽  
...  

ABSTRACT Parvin-β is a focal adhesion protein downregulated in human breast cancer cells. Loss of Parvin-β contributes to increased integrin-linked kinase activity, cell-matrix adhesion, and invasion through the extracellular matrix in vitro. The effect of ectopic Parvin-β expression on the transcriptional profile of MDA-MB-231 breast cancer cells, which normally do not express Parvin-β, was evaluated. Particular emphasis was placed upon propagating MDA-MB-231 breast cancer cells in three-dimensional culture matrices. Interestingly, Parvin-β reexpression in MDA-MB-231 cells increased the mRNA expression, serine 82 phosphorylation (mediated by CDK9), and activity of the nuclear hormone receptor peroxisome proliferator-activated receptor gamma (PPARγ), and there was a concomitant increase in lipogenic gene expression as a downstream effector of PPARγ. Importantly, Parvin-β suppressed breast cancer growth in vivo, with associated decreased proliferation. These data suggest that Parvin-β might influence breast cancer progression.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
KyeongJin Kim ◽  
Jin Ku Kang ◽  
Young Hoon Jung ◽  
Sang Bae Lee ◽  
Raffaela Rametta ◽  
...  

AbstractIncreased adiposity confers risk for systemic insulin resistance and type 2 diabetes (T2D), but mechanisms underlying this pathogenic inter-organ crosstalk are incompletely understood. We find PHLPP2 (PH domain and leucine rich repeat protein phosphatase 2), recently identified as the Akt Ser473 phosphatase, to be increased in adipocytes from obese mice. To identify the functional consequence of increased adipocyte PHLPP2 in obese mice, we generated adipocyte-specific PHLPP2 knockout (A-PHLPP2) mice. A-PHLPP2 mice show normal adiposity and glucose metabolism when fed a normal chow diet, but reduced adiposity and improved whole-body glucose tolerance as compared to Cre- controls with high-fat diet (HFD) feeding. Notably, HFD-fed A-PHLPP2 mice show increased HSL phosphorylation, leading to increased lipolysis in vitro and in vivo. Mobilized adipocyte fatty acids are oxidized, leading to increased peroxisome proliferator-activated receptor alpha (PPARα)-dependent adiponectin secretion, which in turn increases hepatic fatty acid oxidation to ameliorate obesity-induced fatty liver. Consistently, adipose PHLPP2 expression is negatively correlated with serum adiponectin levels in obese humans. Overall, these data implicate an adipocyte PHLPP2-HSL-PPARα signaling axis to regulate systemic glucose and lipid homeostasis, and suggest that excess adipocyte PHLPP2 explains decreased adiponectin secretion and downstream metabolic consequence in obesity.


Author(s):  
Jiongwei Pan ◽  
Gang Huang ◽  
Zhangyong Yin ◽  
Xiaoping Cai ◽  
Enhui Gong ◽  
...  

AbstractSignificantly high-expressed circFLNA has been found in various cancer cell lines, but not in lung cancer. Therefore, this study aimed to explore the role of circFLNA in the progression of lung cancer. The target gene of circFLNA was determined by bioinformatics and luciferase reporter assay. Viability, proliferation, migration, and invasion of the transfected cells were detected by CCK-8, colony formation, wound-healing, and transwell assays, respectively. A mouse subcutaneous xenotransplanted tumor model was established, and the expressions of circFLNA, miR-486-3p, XRCC1, CYP1A1, and related genes in the cancer cells and tissues were detected by RT-qPCR, Western blot, or immunohistochemistry. The current study found that miR-486-3p was low-expressed in lung cancer. MiR-486-3p, which has been found to target XRCC1 and CYP1A1, was regulated by circFLNA. CircFLNA was located in the cytoplasm and had a high expression in lung cancer cells. Cancer cell viability, proliferation, migration, and invasion were promoted by overexpressed circFLNA, XRCC1, and CYP1A1 but inhibited by miR-486-3p mimic and circFLNA knockdown. The weight of the xenotransplanted tumor was increased by circFLNA overexpression yet reduced by miR-486-3p mimic. Furthermore, miR-486-3p mimic reversed the effect of circFLNA overexpression on promoting lung cancer cells and tumors and regulating the expressions of miR-486-3p, XRCC1, CYP1A1, and metastasis/apoptosis/proliferation-related factors. However, overexpressed XRCC1 and CYP1A1 reversed the inhibitory effect of miR-486-3p mimic on cancer cells and tumors. In conclusion, circFLNA acted as a sponge of miR-486-3p to promote the proliferation, migration, and invasion of lung cancer cells in vitro and in vivo by regulating XRCC1 and CYP1A1.


BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Wei Zhu ◽  
Hongyang Zhao ◽  
Fenfen Xu ◽  
Bin Huang ◽  
Xiaojing Dai ◽  
...  

Abstract Background Fenofibrate is a fibric acid derivative known to have a lipid-lowering effect. Although fenofibrate-induced peroxisome proliferator-activated receptor alpha (PPARα) transcription activation has been shown to play an important role in the malignant progression of gliomas, the underlying mechanisms are poorly understood. Methods In this study, we analyzed TCGA database and found that there was a significant negative correlation between the long noncoding RNA (lncRNA) HOTAIR and PPARα. Then, we explored the molecular mechanism by which lncRNA HOTAIR regulates PPARα in cell lines in vitro and in a nude mouse glioma model in vivo and explored the effect of the combined application of HOTAIR knockdown and fenofibrate treatment on glioma invasion. Results For the first time, it was shown that after knockdown of the expression of HOTAIR in gliomas, the expression of PPARα was significantly upregulated, and the invasion and proliferation ability of gliomas were obviously inhibited. Then, glioma cells were treated with both the PPARα agonist fenofibrate and si-HOTAIR, and the results showed that the proliferation and invasion of glioma cells were significantly inhibited. Conclusions Our results suggest that HOTAIR can negatively regulate the expression of PPARα and that the combination of fenofibrate and si-HOTAIR treatment can significantly inhibit the progression of gliomas. This introduces new ideas for the treatment of gliomas.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ronggang Luo ◽  
Yi Zhuo ◽  
Quan Du ◽  
Rendong Xiao

Abstract Background To detect and investigate the expression of POU domain class 2 transcription factor 2 (POU2F2) in human lung cancer tissues, its role in lung cancer progression, and the potential mechanisms. Methods Immunohistochemical (IHC) assays were conducted to assess the expression of POU2F2 in human lung cancer tissues. Immunoblot assays were performed to assess the expression levels of POU2F2 in human lung cancer tissues and cell lines. CCK-8, colony formation, and transwell-migration/invasion assays were conducted to detect the effects of POU2F2 and AGO1 on the proliferaion and motility of A549 and H1299 cells in vitro. CHIP and luciferase assays were performed for the mechanism study. A tumor xenotransplantation model was used to detect the effects of POU2F2 on tumor growth in vivo. Results We found POU2F2 was highly expressed in human lung cancer tissues and cell lines, and associated with the lung cancer patients’ prognosis and clinical features. POU2F2 promoted the proliferation, and motility of lung cancer cells via targeting AGO1 in vitro. Additionally, POU2F2 promoted tumor growth of lung cancer cells via AGO1 in vivo. Conclusion We found POU2F2 was highly expressed in lung cancer cells and confirmed the involvement of POU2F2 in lung cancer progression, and thought POU2F2 could act as a potential therapeutic target for lung cancer.


2021 ◽  
Vol 22 (9) ◽  
pp. 4670
Author(s):  
Cinzia Buccoliero ◽  
Manuela Dicarlo ◽  
Patrizia Pignataro ◽  
Francesco Gaccione ◽  
Silvia Colucci ◽  
...  

Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) is a protein that promotes transcription of numerous genes, particularly those responsible for the regulation of mitochondrial biogenesis. Evidence for a key role of PGC1α in bone metabolism is very recent. In vivo studies showed that PGC1α deletion negatively affects cortical thickness, trabecular organization and resistance to flexion, resulting in increased risk of fracture. Furthermore, in a mouse model of bone disease, PGC1α activation stimulates osteoblastic gene expression and inhibits atrogene transcription. PGC1α overexpression positively affects the activity of Sirtuin 3, a mitochondrial nicotinammide adenina dinucleotide (NAD)-dependent deacetylase, on osteoblastic differentiation. In vitro, PGC1α overexpression prevents the reduction of mitochondrial density, membrane potential and alkaline phosphatase activity caused by Sirtuin 3 knockdown in osteoblasts. Moreover, PGC1α influences the commitment of skeletal stem cells towards an osteogenic lineage, while negatively affects marrow adipose tissue accumulation. In this review, we will focus on recent findings about PGC1α action on bone metabolism, in vivo and in vitro, and in pathologies that cause bone loss, such as osteoporosis and type 2 diabetes.


2000 ◽  
Vol 164 (2) ◽  
pp. 1046-1054 ◽  
Author(s):  
Rolf Thieringer ◽  
Judy E. Fenyk-Melody ◽  
Cheryl B. Le Grand ◽  
Beverly A. Shelton ◽  
Patricia A. Detmers ◽  
...  

Endocrinology ◽  
2009 ◽  
Vol 150 (9) ◽  
pp. 4074-4083 ◽  
Author(s):  
Ji-Won Kim ◽  
Young-Hye You ◽  
Dong-Sik Ham ◽  
Jae-Hyoung Cho ◽  
Seung-Hyun Ko ◽  
...  

Abstract Peroxisome proliferator-activated receptor γ-coactivator-1α (PGC-1α) is significantly elevated in the islets of animal models of diabetes. However, the molecular mechanism has not been clarified. We investigated whether the suppression of PGC-1α expression protects against β-cell dysfunction in vivo and determined the mechanism of action of PGC-1α in β-cells. The studies were performed in glucolipotixicity-induced primary rat islets and INS-1 cells. In vitro and in vivo approaches using adenoviruses were used to evaluate the role of PGC-1α in glucolipotoxicity-associated β-cell dysfunction. The expression of PGC-1α in cultured β-cells increased gradually with glucolipotoxicity. The overexpression of PGC-1α also suppressed the expression of the insulin and β-cell E-box transcription factor (BETA2/NeuroD) genes, which was reversed by PGC-1α small interfering RNA (siRNA). BETA2/NeuroD, p300-enhanced BETA2/NeuroD, and insulin transcriptional activities were significantly suppressed by Ad-PGC-1α but were rescued by Ad-siPGC-1α. PGC-1α binding at the glucocorticoid receptor site on the BETA2/NeuroD promoter increased in the presence of PGC-1α. Ad-siPGC-1α injection through the celiac arteries of 90% pancreatectomized diabetic rats improved their glucose tolerance and maintained their fasting insulin levels. The suppression of PGC-1α expression protects the glucolipotoxicity-induced β-cell dysfunction in vivo and in vitro. A better understanding of the functions of molecules such as PGC-1α, which play key roles in intracellular fuel regulation, could herald a new era of the treatment of patients with type 2 diabetes mellitus by providing protection from glucolipotoxicity, which is an important cause of the development and progression of the disease.


2019 ◽  
Vol 241 (3) ◽  
pp. 175-187 ◽  
Author(s):  
Fazal Wahab ◽  
Ikram Ullah Khan ◽  
Ignacio Rodriguez Polo ◽  
Hira Zubair ◽  
Charis Drummer ◽  
...  

Irisin, encoded by the FNDC5 gene, is a recently discovered endocrine factor mainly secreted as a myokine and adipokine. However, irisin/FNDC5 expression has also been reported in different other organs including components of the reproductive axis. Yet, there is the scarcity of data on FNDC5/irisin expression, regulation and its reproductive effects, particularly in primates. Here, we report the expression of FNDC5/irisin, along with PGC1A (peroxisome proliferator-activated receptor gamma coactivator 1-alpha) and ERRA (estrogen-related receptor alpha), in components of the reproductive axis of marmoset monkeys. Hypothalamic FNDC5 and ERRA transcript levels are developmentally regulated in both male and female. We further uncovered sex-specific differences in FNDC5, ERRA and PGC1A expression in muscle and the reproductive axis. Moreover, irisin and ERRα co-localize in the marmoset hypothalamus. Additionally, in the arcuate nucleus of rhesus monkeys, the number of irisin+ cells was significantly increased in short-term fasted monkeys as compared to ad libitum-fed monkeys. More importantly, we observed putative interaction of irisin-immunoreactive fibers and few GnRH-immunoreactive cell bodies in the mediobasal hypothalamus of the rhesus monkeys. Functionally, we noted a stimulatory effect of irisin on GnRH synthesis and release in mouse hypothalamic neuronal GT1-7 cells. In summary, our findings show that FNDC5 and irisin are developmentally, metabolic-status dependently and sex-specifically expressed in the primate hypothalamic–pituitary–gonadal axis and exert a stimulatory effect on GnRH expression and release in mouse hypothalamic cells. Further studies are required to confirm the reproductive effects of irisin in vivo and to illuminate the mechanisms of its regulation.


2021 ◽  
Vol 49 (11) ◽  
pp. 030006052110550
Author(s):  
Xing Wang ◽  
Shuchun Chen ◽  
Dan Lv ◽  
Zelin Li ◽  
Luping Ren ◽  
...  

Objective To investigate the effect of liraglutide on the browning of white fat and the suppression of obesity via regulating microRNA (miR)-27b in vivo and in vitro. Methods Sprague-Dawley rats were fed a high-fat (HF) diet and 3T3-L1 pre-adipocytes were differentiated into mature white adipocytes. Rats and mature adipocytes were then treated with different doses of liraglutide. The mRNA and protein levels of browning-associated proteins, including uncoupling protein 1 (UCP1), PR domain containing 16 (PRDM16), CCAAT enhancer binding protein β (CEBPβ), cell death-inducing DFFA-like effector A (CIDEA) and peroxisome proliferator-activated receptor-γ-coactivator 1α (PGC-1α), were detected using quantitative real-time polymerase chain reaction and Western blotting. Results Liraglutide decreased body weight and reduced the levels of blood glucose, triglyceride and low-density lipoprotein cholesterol in HF diet-fed rats. Liraglutide increased the levels of UCP1, PRDM16, CEBPβ, CIDEA and PGC-1α in vivo and vitro. The levels of miR-27b were upregulated in HF diet-fed rats, whereas liraglutide reduced the levels of miR-27b. In vitro, overexpression of miR-27b decreased the mRNA and protein levels of UCP1, PRDM16, CEBPβ, CIDEA and PGC-1α. Transfection with the miR-27b mimics attenuated the effect of liraglutide on the browning of white adipocytes. Conclusion Liraglutide induced browning of white adipose through regulation of miR-27b.


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