scholarly journals SNAI2-mediated direct repression of BIM protects rhabdomyosarcoma from ionizing radiation

2021 ◽  
Author(s):  
Long Wang ◽  
Nicole R. Hensch ◽  
Kathryn Bondra ◽  
Prethish Sreenivas ◽  
Xiang Ru Zhao ◽  
...  

AbstractIonizing radiation (IR) and chemotherapy are the mainstays of treatment for patients with rhabdomyosarcoma (RMS). Yet, the molecular mechanisms that underlie the success or failure of radiotherapy remain unclear. The transcriptional repressor SNAI2 was previously identified as a key regulator of IR sensitivity in normal and malignant stem cells through its repression of the proapoptotic BH3-only gene PUMA. Here, we demonstrate a clear correlation between SNAI2 expression levels and radiosensitivity across multiple RMS cell lines. Moreover, modulating SNAI2 levels in RMS cells through its overexpression or knockdown can alter radiosensitivity in vitro and in vivo. SNAI2 expression reliably promotes overall cell growth and inhibits mitochondrial apoptosis following exposure to IR, with either variable or minimal effects on differentiation and senescence, respectively. Importantly, SNAI2 knockdown results in a striking increase in expression of the proapoptotic BH3-only gene BIM, and ChIP-seq experiments establish that SNAI2 is a direct repressor of BIM. Since the P53 pathway is nonfunctional in the RMS cells used in this study, we have identified a new, P53-independent SNAI2/BIM axis that could potentially predict clinical responses to IR treatment and be exploited to improve RMS therapy.HighlightsSNAI2 expression levels are directly correlated with protection from radiation in rhabdomyosarcoma.Loss of SNAI2 primes rhabdomyosarcomas for IR-induced apoptosis.SNAI2 directly represses the expression of the proapoptotic BH3-only gene BIM.

Nutrients ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 963 ◽  
Author(s):  
Chenxuan Wu ◽  
Jun Liu ◽  
Yanbin Tang ◽  
Yanxiao Li ◽  
Qiaojuan Yan ◽  
...  

Natural polysaccharides, particularly galactomannans, are potential candidates for treatment of alcoholic liver diseases (ALD). However, applications are restricted due to the physicochemical properties associated with the high molecular weight. In this work, guar gum galactomannans were partially hydrolyzed by β-mannanase, and the molecular mechanisms of hepatoprotective effects were elucidated both in vitro and in vivo. Release of lactate dehydrogenase and cytochrome C were attenuated by partially hydrolyzed guar gum (PHGG) in HepG2 cells, due to protected cell and mitochondrial membrane integrity. PHGG co-administration decreased serum amino transaminases and cholinesterase levels of acute alcohol intoxicated mice, while hepatic pathologic morphology was depleted. Activity of superoxide dismutase, catalase, and glutathione peroxidase was recovered to 198.2, 34.5, 236.0 U/mg protein, respectively, while malondialdehyde level was decreased by 76.3% (PHGG, 1000 mg/kg∙day). Co-administration of PHGG induced a 4.4-fold increment of p-AMPK expression, and lipid metabolism was mediated. PHGG alleviated toll-like-receptor-4-mediated inflammation via the signaling cascade of MyD88 and IκBα, decreasing cytokine production. Moreover, mediated expression of Bcl-2 and Bax was responsible for inhibited acute alcohol-induced apoptosis with suppressed cleavage of caspase 3 and PARP. Findings gained suggest that PHGG can be used as functional food supplement for the treatment of acute alcohol-induced liver injury.


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 10 (1) ◽  
Author(s):  
Minyoung Lee ◽  
Eugene Shin ◽  
Jaehyun Bae ◽  
Yongin Cho ◽  
Ji-Yeon Lee ◽  
...  

Abstract Dipeptidyl peptidase-4 inhibitors (DPP4i) are antidiabetic medications that prevent cleavage of incretin hormones by dipeptidyl peptidase-4 (DPP4). DPP4 is ubiquitously expressed, and its hepatic DPP4 expression is upregulated under non-alcoholic steatohepatitis (NASH) conditions. We investigated the effect of DPP4i treatment on NASH pathogenesis, as well as its potential underlying molecular mechanisms. Mice were randomly divided into three groups: Group 1, chow-fed mice treated with vehicle for 20 weeks; Group 2, high-fat, high-fructose, and high-cholesterol Amylin liver NASH (AMLN) diet-fed mice treated with vehicle for 20 weeks; Group 3, AMLN diet-fed mice treated with vehicle for the first 10 weeks, followed by the DPP4i teneligliptin (20 mg/kg/day) for additional 10 weeks. DPP4i administration reduced serum liver enzyme and hepatic triglyceride levels and markedly improved hepatic steatosis and fibrosis in the AMLN diet-induced NASH model. In vivo, NASH alleviation significantly correlated with the suppression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor-mediated apoptosis and downregulated hepatic DPP4 expression. In vitro, DPP4i treatment significantly decreased the markers of TRAIL receptor-mediated lipoapoptosis and suppressed DPP4 expression in palmitate-treated hepatocytes. In conclusion, DPP4i may efficiently attenuate the pathogenesis of AMLN diet-induced NASH in mice by suppressing lipotoxicity-induced apoptosis, possibly by modulating hepatic DPP4 expression.


Blood ◽  
2009 ◽  
Vol 114 (9) ◽  
pp. 1987-1998 ◽  
Author(s):  
Tong-Young Lee ◽  
Stefan Muschal ◽  
Elke A. Pravda ◽  
Judah Folkman ◽  
Amir Abdollahi ◽  
...  

Angiostatin, a proteolytic fragment of plasminogen, is a potent endogenous antiangiogenic agent. The molecular mechanisms governing angiostatin's antiangiogenic and antitumor effects are not well understood. Here, we report the identification of mitochondrial compartment as the ultimate target of angiostatin. After internalization of angiostatin into the cell, at least 2 proteins within the mitochondria bind this molecule: malate dehydrogenase, a member of Krebs cycle, and adenosine triphosphate synthase. In vitro and in vivo studies revealed differential regulation of key prosurvival and angiogenesis-related proteins in angiostatin-treated tumors and tumor-endothelium. Angiostatin induced apoptosis via down-regulation of mitochondrial BCL-2. Angiostatin treatment led to down-regulation of c-Myc and elevated levels of another key antiangiogenic protein, thrombospondin-1, reinforcing its antitumor and antiangiogenic effects. Further evidence is provided for reduced recruitment and infiltration of bone marrow–derived macrophages in angiostatin-treated tumors. The observed effects of angiostatin were restricted to the tumor site and were not observed in other major organs of the mice, indicating unique tumor specific bioavailability. Together, our data suggest mitochondria as a novel target for antiangiogenic therapy and provide mechanistic insights to the antiangiogenic and antitumor effects of angiostatin.


Author(s):  
Chuanjie Zhang ◽  
Yan Shen ◽  
Lili Gao ◽  
Xiaojing Wang ◽  
Da Huang ◽  
...  

ObjectiveThe aim of this study is to investigate the biological functions and the underlying mechanisms of DNA polymerase epsilon subunit 2 (POLE2) in renal cell carcinoma (RCC).MethodsThe datasets of POLE2 expression in The Cancer Genome Atlas Kidney Clear Cell Carcinoma (TCGA-KIRC) and International Cancer Genome Consortium (ICGC) databases was selected and the correlation between POLE2 and various clinicopathological parameters was analyzed. The POLE2 expression in RCC tissues was examined by immunohistochemistry. The POLE2 knockdown cell lines were constructed. In vitro and in vivo experiments were carried out to investigate the function of POLE2 on cellular biology of RCC, including cell viability assay, clone formation assay, flow cytometry, wound-healing assay, Transwell assay, qRT-PCR, Western blot, etc. Besides, microarray, co-immunoprecipitation, rescue experiment, and Western blot were used to investigate the molecular mechanisms underlying the functions of POLE2.ResultsPOLE2 was overexpressed in RCC tissues, and high expression of POLE2 was correlated with poor prognosis of RCC. Furthermore, knockdown of POLE2 significantly inhibited cell proliferation, migration, and facilitated apoptosis in vitro. In vivo experiments revealed that POLE2 attenuated RCC tumorigenesis and tumor growth. we also illuminated that stanniocalcin 1 (STC1) was a downstream gene of POLE2, which promoted the occurrence and development of RCC. Besides, knockdown of POLE2 significantly upregulated the expression levels of Bad and p21 while the expression levels of HSP70, IGF-I, IGF-II, survivin, and sTNF-R1 were significantly downregulated. Western blot analysis also showed that knockdown of POLE2 inhibited the expression levels of Cancer-related pathway proteins including p-Akt, CCND1, MAPK9, and PIK3CA.ConclusionKnockdown of POLE2 attenuates RCC cells proliferation and migration by regulating STC1, suggesting that POLE2-STC1 may become a potential target for RCC therapy.


2020 ◽  
Author(s):  
Arindam Ghosh ◽  
Anup Som

ABSTRACTPluripotent stem cells (PSCs) have been observed to occur in two distinct states — naive and primed. Both naive and primed state PSCs can give rise to tissues of all the three germ layers in vitro but differ in their potential to generate germline chimera in vivo. Understanding the molecular mechanisms that govern these two states of pluripotency in human can open up a plethora of opportunities for studying early embryonic development and in biomedical applications. In this work, we use weighted gene co-expression network (WGCN) approach to identify the key molecular makers and their interactions that define the two distinct pluripotency states. Signed-hybrid WGCN was reconstructed from transcriptomic data (RNA-seq) of naive and primed state pluripotent samples. Our analysis revealed two sets of genes that are involved in establishment and maintenance of naive (4791 genes) and primed (5066 genes) states. The naive state genes were found to be enriched for biological processes and pathways related to metabolic processes while primed state genes were associated with system development. Further, we identified the top 10% genes by intra-modular connectivity as hubs and the hub transcription factors for each group, thus providing a three-tier list of genes associated with naive and primed states of pluripotency in human.HIGHLIGHTSWeighted gene co-expression network analysis (WGCNA) identified 4791 and 5066 genes to be involved in naive and primed states of human pluripotency respectively.Functional and pathway enrichment analysis revealed the naive genes were mostly related to metabolic processes and primed genes to system development.The top 10% genes based on intra-modular connectivity from each group were defined as hubs.Identified 52 and 33 transcription factors among the naive and primed module hubs respectively.The transcription factors might play a switch on-off mechanism in induction of the two pluripotent states.


2021 ◽  
Author(s):  
qing liu ◽  
gang peng ◽  
Jun Su ◽  
zeyou wang ◽  
songhua xiao

Abstract Aberrant expression of long noncoding RNAs plays a pivotal role in tumorigenesis. Recently, several studies have showed that the LINC00152 gene is upregulated in a variety of tumors and plays an oncogene role; however, its underlying molecular mechanisms in glioblastoma remain unclear. In this study, we found that LINC00152 was upregulated in gliomas and its expression was significantly associated with high tumor aggressiveness and poor outcomes for glioma patients through bioinformatics analysis. Functionally, the knockdown of LINC00152 not only inhibited malignant behaviors of glioma, such as proliferation and invasion of glioma cells and induced apoptosis in vitro but also suppressed tumorigenesis in vivo. Mechanistically, results of the bioinformatics analysis and experimental studies confirmed that LINC00152 and RAB10 as the targets of miR-107, and LINC00152 might act as a sponge for miR-107 to regulate the expression of RAB10 in glioblastoma. Additionally, silencing miR-107 reversed the effects induced by LINC00152 knockdown on glioblastoma cells both in vitro and in vivo. Taken together, our data suggested that LINC00152 is a candidate prognostic marker of glioma, and that the LINC00152/MIR-107/RAB10 axis plays a pivotal role in regulation of the glioma malignancy, and therefore, targeting the axis might be an effective therapeutic strategy to treat glioma.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4297-4297
Author(s):  
Jing Liu ◽  
Shu-Ling Wang ◽  
Lin Fang ◽  
Mao Ye ◽  
Zhi-Wei Sun ◽  
...  

Abstract Abstract 4297 Leukemia is one of the most life-threatening cancers today, and acute promyelogenous leukemia is a common type of leukemia. We have previously shown that lycorine, a natural alkaloid extract from Amaryllidaceae, exhibited anti-leukemia effects in vitro and in vivo. Lycorine treatment of HL-60 cell arrested cell cycle at G2/M phase and induced apoptosis. In the present study, we sought to explore the molecular mechanisms for the anti-leukemia action of lycorine. Gene chip analysis revealed that lycorine treatment of HL-60 cells induced more than 9 fold increase of p21, a cyclin-dependent kinase inhibitor, whose expression is mainly regulated by p53. Since HL-60 cells are p53 null, the above findings suggest that lycorine activates p21 expression through p53-independent pathway. To further explore the alternative pathways for the activation of p21 induced by lycorine, we examined the effect of lycorine on the expression of Rb, pRb, E2F, c-Myc and HDACs which have shown to regulate p21 expression. We show that expression of pRb (ser780) and c-Myc was down-regulated, Rb and E2F were up-regulated, while the expression of HDAC1 and HDAC3 was not changed. Together these findings suggest that lycorine exerts its anti-leukemia effect by activating p21 expression via pRb/E2F and c-Myc pathways. Disclosures: No relevant conflicts of interest to declare.


2021 ◽  
Author(s):  
Ran Mei ◽  
Xichun Cui ◽  
Lili Zheng ◽  
Li Jingyi

Abstract Background: Breast cancer (BRCA) is the most common type of women's cancer with a high incidence. The function of gamma-aminobutyric acid A receptor θ subunit (GABRQ) has been studied in other cancers. The results demonstrated that the expression levels of GABRQ were closely associated with tumor prognosis. However, the functions and mechanisms of GABRQ in BRCA remain unclear.Materials and methods: We used the public genome datasets and a tissue microarray (TMA) cohort to analyze the GABRQ expression levels. We performed Immunohistochemistry (IHC) and Western blot to determine GABRQ expression in BRCA cell lines and tissues. Cell proliferation was assessed by EDU assay and colony formation assay. Transwell assay was carried out to investigate the cell invasion ability in vitro and Xenograft nude mouse model was constructed to test the function of GABRQ on tumor growth in vivo. Moreover, we utilized bioinformatic analysis to identify the potential molecular mechanisms mediated by GABRQ modification in BRCA.Results: GABRQ was markedly up-regulated in BRCA tissues, and the expression levels of GABRQ were closely associated with BRCA prognosis. Functional analysis elucidated that knockdown of GABRQ could suppress BRCA cell growth and invasion in vitro, and inhibit tumor development in vivo. Moreover, we found that GABRQ overexpression activated the EMT signaling pathway.Conclusions: These results demonstrated that the function of GABRQ in BRCA progression provided potential prognostic predictors for BRCA patients.


2021 ◽  
Vol 11 ◽  
Author(s):  
Anhui Yang ◽  
Zhen Sun ◽  
Rui Liu ◽  
Xin Liu ◽  
Yue Zhang ◽  
...  

BackgroundLiver cancer is one of the most malignant human cancers, with few treatments and a poor prognosis. Erianin (ERN) is a natural compound with multiple pharmacological activities that has been reported to have numerous excellent effects against liver cancer in experimental systems. However, its application in vivo has been limited due to its poor aqueous solubility and numerous off-target effects. This study aimed to improve the therapeutic efficacy of ERN by developing novel ERN-loaded tumor-targeting nanoparticles.ResultsIn this study, ERN was loaded into liposomes by ethanol injection (LP-ERN), and the resulting LP-ERN nanoparticles were treated with transferrin to form Tf-LP-ERN to improve the solubility and enhance the tumor-targeting of ERN. LP-ERN and Tf-LP-ERN nanoparticles had smooth surfaces and a uniform particle size, with particle diameters of 62.60 nm and 88.63 nm, respectively. In HepG2 and SMMC-7721 cells, Tf-LP-ERN induced apoptosis, decreased mitochondrial membrane potentials and increased ERN uptake more effectively than free ERN and LP-ERN. In xenotransplanted mice, Tf-LP-ERN inhibited tumor growth, but had a minimal effect on body weight and organ morphology. In addition, Tf-LP-ERN nanoparticles targeted tumors more effectively than free ERN and LP-ERN nanoparticles, and in tumor tissues Tf-LP-ERN nanoparticles promoted the cleavage PARP-1, caspase-3 and caspase-9, increased the expression levels of Bax, Bad, PUMA, and reduced the expression level of Bcl-2. Moreover, in the spleen of heterotopic tumor model BALB/c mice, ERN, LP-ERN and Tf-LP-ERN nanoparticles increased the expression levels of Nrf2, HO-1, SOD-1 and SOD-2, but reduced the expression levels of P-IKKα+β and P-NF-κB, with Tf-LP-ERN nanoparticles being most effective in this regard. Tf-LP-ERN nanoparticles also regulated the expression levels of TNF-α, IL-10 and CCL11 in serum.ConclusionTf-LP-ERN nanoparticles exhibited excellent anti-liver cancer activity in vivo and in vitro by inducing cellular apoptosis, exhibiting immunoregulatory actions, and targeting tumor tissues, and did so more effectively than free ERN and LP-ERN nanoparticles. These results suggest that the clinical utility of a Tf-conjugated LP ERN-delivery system for the treatment of liver cancer warrants exploration.


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