scholarly journals PPA1 promotes NSCLC progression via a JNK- and TP53-dependent manner

Oncogenesis ◽  
2019 ◽  
Vol 8 (10) ◽  
Author(s):  
Dehong Luo ◽  
Daishun Liu ◽  
Wen Shi ◽  
Huimin Jiang ◽  
Wei Liu ◽  
...  

Abstract Inorganic pyrophosphatase (PPA1) promotes tumor progression in several tumor types. However, the underlying mechanism remains elusive. Here, we disclosed that PPA1 expression is markedly upregulated in lung carcinoma tissue versus normal lung tissue. We also found that the non-small cell lung cancer (NSCLC) cell lines show increased PPA1 expression levels versus normal lung cell line control. Moreover, the knockdown of PPA1 promotes cell apoptosis and inhibits cell proliferation. Whereas, the ectopic expression of PPA1 reduces cell apoptosis and enhances cell proliferation. Most interestingly, the expression of mutant PPA1 (D117A) significantly abolishes PPA1-mediated effect on cell apoptosis and proliferation. The underlying mechanism demonstrated that TP53 expression deficiency or JNK inhibitor treatment could abolish PPA1-mediated NSCLC progression. In summary, the aforementioned findings in this study suggest a new pathway the PPA1 mediates NSCLC progression either via TP53 or JNK. Most important, the pyrophosphatase activity is indispensible for PPA1-mediated NSCLC progression. This may provide a promising target for NSCLC therapy.

2021 ◽  
Author(s):  
Wenzhi Shen ◽  
Wenfei Du ◽  
Yanping Li ◽  
Yongming Huang ◽  
Xinyu Jiang ◽  
...  

Abstract Background: Previous studies have shown that TIFA (TNF receptor associated factor (TRAF)-interacting protein with a Forkhead-associated (FHA) domain) plays different roles in various tumor types. However, the function of TIFA in colorectal cancer (CRC) remains unclear. The goal of this study is to uncover the biological function and molecular mechanism of TIFA in CRC.Methods: Tissue microarrays were used to evaluate TIFA expression. Cancer cell proferation assays were performed in TIFA knockdown and overexpressing cells in vitro and in a xenograft model in vivo. Human phosphokinase array, immunoprecipitation assays were performed to explore the underlying mechanism.Results: We disclosed that the expression of TIFA was marked increased in CRC versus normal tissue, and positively correlated with CRC TNM stages. In agreement, we found that the CRC cell lines show increased TIFA expression levels versus normal control. The knockdown of TIFA inhibited cell proliferation but have no effects on cell apoptosis in vitro and in vivo. Moreover, the ectopic expression of TIFA enhanced cell proliferation ability in vitro and in vivo. In contrast, the expression of mutant TIFA (T9A, oligomerization site mutation; D6, TRAF6 binding site deletion) alternatively abolished TIFA mediated cell proliferation enhancement. Exploration of the underlying mechanism demonstrated that the protein synthesis associated kinase RSK and PRAS40 activation were all responsible for TIFA mediated CRC progression. Conclusions: The above results described a model of TIFA in mediating CRC progression. This may provide a promising target for CRC therapy.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Jipeng Lu ◽  
Zhongxiong Wu ◽  
Ying Xiong

Abstract Background Osteoarthritis (OA) is a joint disease characterized via destruction of cartilage. Chondrocyte damage is associated with cartilage destruction during OA. Long noncoding RNAs (lncRNAs) are implicated in the regulation of chondrocyte damage in OA progression. This study aims to investigate the role and underlying mechanism of lncRNA homeobox antisense intergenic RNA (HOTAIR) in OA chondrocyte injury. Methods Twenty-three OA patients and healthy controls without OA were recruited. Chondrocytes were isolated from OA cartilage tissues. HOTAIR, microRNA-107 (miR-107) and C-X-C motif chemokine ligand 12 (CXCL12) levels were measured by quantitative real-time polymerase chain reaction and western blot. Cell proliferation, apoptosis and extracellular matrix (ECM) degradation were measured using cell counting kit-8, flow cytometry and western blot. The target interaction was explored by bioinformatics, luciferase reporter and RNA immunoprecipitation assays. Results HOTAIR expression was enhanced, and miR-107 level was reduced in OA cartilage samples. HOTAIR overexpression inhibited cell proliferation, but induced cell apoptosis and ECM degradation in chondrocytes. HOTAIR knockdown caused an opposite effect. MiR-107 was sponged and inhibited via HOTAIR, and knockdown of miR-107 mitigated the effect of HOTAIR silence on chondrocyte injury. CXCL12 was targeted by miR-107. CXCL12 overexpression attenuated the roles of miR-107 overexpression or HOTAIR knockdown in the proliferation, apoptosis and ECM degradation. CXCL12 expression was decreased by HOTAIR silence, and restored by knockdown of miR-107. Conclusion HOTAIR knockdown promoted chondrocyte proliferation, but inhibited cell apoptosis and ECM degradation in OA chondrocytes by regulating the miR-107/CXCL12 axis.


2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Qian Liu ◽  
Lijuan Guo ◽  
Hongyan Qi ◽  
Meng Lou ◽  
Rui Wang ◽  
...  

AbstractRibonucleotide reductase (RR) is a unique enzyme for the reduction of NDPs to dNDPs, the building blocks for DNA synthesis and thus essential for cell proliferation. Pan-cancer profiling studies showed that RRM2, the small subunit M2 of RR, is abnormally overexpressed in multiple types of cancers; however, the underlying regulatory mechanisms in cancers are still unclear. In this study, through searching in cancer-omics databases and immunohistochemistry validation with clinical samples, we showed that the expression of MYBL2, a key oncogenic transcriptional factor, was significantly upregulated correlatively with RRM2 in colorectal cancer (CRC). Ectopic expression and knockdown experiments indicated that MYBL2 was essential for CRC cell proliferation, DNA synthesis, and cell cycle progression in an RRM2-dependent manner. Mechanistically, MYBL2 directly bound to the promoter of RRM2 gene and promoted its transcription during S-phase together with TAF15 and MuvB components. Notably, knockdown of MYBL2 sensitized CRC cells to treatment with MK-1775, a clinical trial drug for inhibition of WEE1, which is involved in a degradation pathway of RRM2. Finally, mouse xenograft experiments showed that the combined suppression of MYBL2 and WEE1 synergistically inhibited CRC growth with a low systemic toxicity in vivo. Therefore, we propose a new regulatory mechanism for RRM2 transcription for CRC proliferation, in which MYBL2 functions by constituting a dynamic S-phase transcription complex following the G1/early S-phase E2Fs complex. Doubly targeting the transcription and degradation machines of RRM2 could produce a synthetic inhibitory effect on RRM2 level with a novel potential for CRC treatment.


2021 ◽  
Author(s):  
Suzuko Kinoshita ◽  
Kazuki Takarada ◽  
Yoshihiro H. Inoue

Mechanisms of cancer cell recognition and elimination by the innate immune system remains unclear. Circulating hemocytes are associated with the hematopoietic tumors in Drosophila mxcmbn1 mutant larvae. The innate immune signalling pathways are activated in the fat body to suppress the tumor growth by inducing antimicrobial peptides (AMP). Here, we investigated the regulatory mechanism underlying the activation in the mutant. Reactive oxygen species accumulated in the hemocytes due to induction of dual oxidase and its activator. The hemocytes were also localized on the fat body. These were essential for transmitting the information on tumors toward the fat body to induce AMP expression. Regarding to the tumor recognition, we found that matrix metalloproteinase 1 (MMP1) and MMP2 were highly expressed in the tumors. Ectopic expression of MMP2 was associated with AMP induction in the mutants. Furthermore, the basement membrane components in the tumors were reduced and ultimately lost. The hemocytes may recognize the disassembly in the tumors. Our findings highlight the underlying mechanism via which macrophage-like hemocytes recognize tumor cells and relay the information toward the fat body to induce AMPs. and contribute to uncover the immune system's roles against cancer.


2022 ◽  
Vol 12 (4) ◽  
pp. 873-877
Author(s):  
Dongqian Xie ◽  
Zhicheng Gao ◽  
Mei Liu ◽  
Defeng Wang

Metformin is shown to have hypoglycemic effects. However, the relationship between metformin’s intervention in FFA-induced endoplasmic reticulum stress-mediated insulin resistance (IR) and insulin β-cell apoptosis under high-glucose condition remains unclear. Our study intends to assess their relationship. Human pancreatic β-cells were treated with metformin and cell proliferation and IR were detected by MTT assay along with detection of Wnt/β-catenin signaling by RT-PCR, cell cycle and apoptosis by flow cytometry. Metformin inhibited β cell proliferation which was mediated by FFA-induced endoplasmic reticulum stress in a time-dependent and dose-dependent manner as well as induced cell cycle arrest at G2/M phase. In addition, metformin inhibited β-catenin signaling activation and decreased the expression of c-myc, Dvl-2, survivin, Dvl-3, GSK-3β (p-ser9) and promoted GSK-3 (p-tyr216) and Axin-2 expression. In conclusion, metformin inhibits Wnt/β-catenin signaling and promotes FFA to induce endoplasmic reticulum stress, thereby mediating pancreatic β-cells behaviors.


Cells ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 171
Author(s):  
Chiharu Miyajima ◽  
Yuki Kawarada ◽  
Yasumichi Inoue ◽  
Chiaki Suzuki ◽  
Kana Mitamura ◽  
...  

Transcriptional coactivator with a PDZ-binding motif (TAZ) is one of the mammalian orthologs of Drosophila Yorkie, a transcriptional coactivator of the Hippo pathway. TAZ has been suggested to function as a regulator that modulates the expression of cell proliferation and anti-apoptotic genes in order to stimulate cell proliferation. TAZ has also been associated with a poor prognosis in several cancers, including breast cancer. However, the physiological role of TAZ in tumorigenesis remains unclear. We herein demonstrated that TAZ negatively regulated the activity of the tumor suppressor p53. The overexpression of TAZ down-regulated p53 transcriptional activity and its downstream gene expression. In contrast, TAZ knockdown up-regulated p21 expression induced by p53 activation. Regarding the underlying mechanism, TAZ inhibited the interaction between p53 and p300 and suppressed the p300-mediated acetylation of p53. Furthermore, TAZ knockdown induced cellular senescence in a p53-dependent manner. These results suggest that TAZ negatively regulates the tumor suppressor functions of p53 and attenuates p53-mediated cellular senescence.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Yangfang Ding ◽  
Qi Xie ◽  
Wenjing Liu ◽  
Zhaohai Pan ◽  
Xinmei Fan ◽  
...  

The botanical constituents of Stellera chamaejasme Linn. exhibit various pharmacological and medicinal activities. Neochamaejasmin A (NCA), one main active constituent of S. chamaejasme, inhibits cell proliferation and induces cell apoptosis in several types of tumor cells. However, the antitumor effect of NCA on hepatocellular carcinoma cells is still unclear. In this study, NCA (36.9, 73.7, and 147.5 μM) significantly inhibited hepatoblastoma-derived HepG2 cell proliferation in a concentration-dependent manner. Hoechst 33258 staining and flow cytometry showed that apoptotic morphological changes were observed and the apoptotic rate was significantly increased in NCA-treated HepG2 cells, respectively. Additionally, the levels of Bax, cleaved caspase-3, and cytoplasmic cytochrome c were increased, while the level of Bcl-2 was decreased in NCA-treated HepG2 cells when compared with the control group. Moreover, we found that the reactive oxygen species (ROS) level was significantly higher and the mitochondrial membrane potential was remarkably lower in NCA-treated HepG2 cells than in the control group. Further studies demonstrated that the levels of p-JNK and p-ERK1/2 were significantly upregulated in NCA-treated HepG2 cells, and pretreatment with JNK and ERK1/2 inhibitors, SP600125 and PD0325901, respectively, suppressed NCA-induced cell apoptosis of HepG2 cells. In addition, NCA also significantly inhibited human hepatoma BEL-7402 cell proliferation and induced cell apoptosis through the ROS-mediated mitochondrial apoptotic pathway. These results implied that NCA induced mitochondrial-mediated cell apoptosis via ROS-dependent activation of the ERK1/2/JNK signaling pathway in HepG2 cells.


2019 ◽  
Vol 10 (11) ◽  
Author(s):  
Ying Yang ◽  
Nandan Wu ◽  
Yihui Wu ◽  
Haoting Chen ◽  
Jin Qiu ◽  
...  

Abstract Retinoblastoma (RB) is the most common primary intraocular malignancy in children. Intravitreal chemotherapy achieves favorable clinical outcomes in controlling RB vitreous seeds, which are a common reason for treatment failure. Thus, a novel, effective and safe intravitreal chemotherapeutic drug is urgently required. The malaria drug artesunate (ART) recently demonstrated remarkable anticancer effects with mild side effects. The purpose of this study is to investigate the anti-RB efficacy, the underlying mechanism and the intraocular safety of ART. Herein, we verified that ART inhibits RB cell viability and induces cell apoptosis in a dose- and time-dependent manner. Microarray analysis revealed that Kruppel-like factor 6 (KLF6) was upregulated after ART treatment, and this was further confirmed by real-time PCR and western blot assays. Silencing of KLF6 expression significantly reversed ART-induced RB cell growth inhibition and apoptosis. Furthermore, ART activated mitochondria-mediated apoptosis of RB cells, while silencing KLF6 expression significantly inhibited this effect. In murine xenotransplantation models of RB, we further confirmed that ART inhibits RB tumor growth, induces tumor cell apoptosis and upregulates KLF6 expression. In addition, KLF6 silencing attenuates ART-mediated inhibition of tumor growth in vivo. Furthermore, we proved that intravitreal injection of ART in Sprague-Dawley (SD) rats is safe, with no obvious retinal function damage or structural disorders observed by electrophysiology (ERG), fundal photographs, fundus fluorescein angiography (FFA) or optical coherence tomography (OCT) examinations. Collectively, our study revealed that ART induces mitochondrial apoptosis of RB cells via upregulating KLF6, and our results may extend the application of ART to the clinic as an effective and safe intravitreal chemotherapeutic drug to treat RB, especially RB with vitreous seeds.


2017 ◽  
Vol 41 (2) ◽  
pp. 784-794 ◽  
Author(s):  
Ying Zong ◽  
Shijie Feng ◽  
Jinwei Cheng ◽  
Chenlin Yu ◽  
Guocai Lu

Background/Aims: Activating transcription factor 4 (ATF4) is a member of the activating transcription factor family which regulates the expression of genes involved in amino acid metabolism, redox homeostasis and ER stress responses. ATF4 is also over-expressed in human solid tumors, although its effect on responsiveness to radiation is largely unexplored. Methods: Real-time PCR was used to detect ATF4 mRNA levels in cells treated with different doses of 60Coγ radiation. Cell viability was assayed using a cell counting kit. The cell cycle was analyzed using flow cytometry, and cell apoptosis was assayed using Annexin V-PI double labeling. Small interfering RNA (siRNA) against ATF4 was transfected into ECV304 cells using Lipofectamine 2000. An ATF4 over-expression plasmid (p-ATF4-CGN) was transfected into HEK293 cells that endogenously expressed low levels of ATF4. The levels of intracellular reactive oxygen species (ROS) were measured using CM-H2DCFDA as a probe. Results: ATF4 mRNA and protein expression levels were higher after radiation and increased in a dose- and time-dependent manner in AHH1 lymphoblast cells (P < 0.05). An increase in ATF4 levels was also observed after radiation in primary murine spleen cells, human endothelial ECV304 cells, human liver LO2 cells, breast cancer MCF7 cells, and human hepatocellular carcinoma HEPG2 cells. No change was observed in human embryonic kidney 293 (HEK293) cells. Over-expressing ATF4 in HEK293 cells inhibited cell proliferation, increased cell apoptosis and significantly increased the proportion of cells in G1 phase. Conversely, when ATF4 expression was knocked down using siRNA in ECV304 cells, it protected the cells from radiation-induced apoptosis. These findings suggest that ATF4 may play a role in radiation-induced cell killing by inhibiting cell proliferation and promoting cell apoptosis. Conclusions: In this study, we found that radiation up-regulated the expression of ATF4. We used ATF4 knockdown and over-expression systems to show that ATF4 may play a role in radiation-induced cellular apoptosis.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Jie Wang ◽  
Chao Chen ◽  
Shiying Wang ◽  
Yong Zhang ◽  
Peihao Yin ◽  
...  

Aims. To investigate the anticolorectal cancer (CRC) effects of Bufalin, a bioactive polyhydroxysteroid from Venenum Bufonis, using HCT116 human CRC cell and an established orthotopic xenograft model in mice, and to explore the mechanisms of action.Material and Methods. Cultured HCT116 cells or BALB/c mice with orthotopic tumor were treated by Bufalin (positive control: 5-FU). Cell proliferation, apoptosis, and cycling were determined by MTT, Annexin V/PI staining, and flow cytometry, respectively. In mice, tumor inhibition rate and animal survival were calculated. The expressions of PTEN/phosphate-PTEN, AKT/phosphate-AKT, Bad, Bcl-xl, Bax, or Caspase-3 in cells and/or tumors were determined by Western blot or immunohistochemical staining.Results. Bufalin significantly inhibited cell proliferation and induced cell apoptosis and cycle arrest in a dose/time-dependent manner. In the animal model, Bufalin treatment resulted in significant inhibition of tumor growth and prolonged survival. In the Bufalin-treated cultured cells and/or xenograft tumors, the expressions of PTEN, Bad, Bax, and Caspase-3 were significantly increased, while p-AKT and Bcl-xL significantly decreased.Conclusions. Our results indicate that Bufalin inhibit cell proliferation and orthotopic tumor growth by inducing cell apoptosis through the intrinsic apoptotic pathway, which is of pivotal significance in the identification of an anticancer drug that may synergize with Bufalin.


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