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Cui Y.,Key Laboratory of Cellular Physiology | Cheng X.,Shanxi Medical University | Zhang C.,Key Laboratory of Cellular Physiology | Wang C.,East China Normal University | Guadagno T.M.,H. Lee Moffitt Cancer Center and Research Institute
Journal of Biological Chemistry | Year: 2010

Mps1 is a dual specificity protein kinase with key roles in regulating the spindle assembly checkpoint and chromosome-microtubule attachments. Consistent with these mitotic functions, Mps1 protein levels fluctuate during the cell cycle, peaking at early mitosis and abruptly declining during mitotic exit and progression into the G1 phase. Although evidence in budding yeast indicates that Mps1is targeted for degradation at anaphase by the anaphase-promoting complex (APC)-cCdc20 complex, little is known about the regulatory mechanisms that govern Mps1 protein levels in human cells. Here, we provide evidence for the ubiquitin ligase/proteosome pathway in regulating human Mps1 levels during late mitosis through G1 phase. First, we showed that treatment of HEK 293T cells with the proteosome inhibitor MG132 resulted in an increase in both the polyubiquitination and the accumulation of Mps1 protein levels. Next, Mps1 was shown to co-precipitate with APC and its activators Cdc20 and Cdh1 in a cell cycle-dependent manner. Consistent with this, overexpression of Cdc20 or Cdh1 led to a marked reduction of endogenous Mps1 levels during anaphase or G1 phase, respectively. In contrast, depletion of Cdc20 or Cdh1 by RNAi treatment both led to the stabilization of Mps1 protein during mitosis or G1 phase, respectively. Finally, we identified a single D-box motif in human Mps1 that is required for its ubiquitination and degradation. Failure to appropriately degrade Mps1 is sufficient to trigger centrosome amplification and mitotic abnormalities in human cells. Thus, our results suggest that the sequential actions of the APC-cCdc20 and APC-cCdh1 ubiquitin ligases regulate the clearance of Mps1 levels and are critical for Mps1 functions during the cell cycle in human cells. © 2010 by The American Society for Biochemistry and Molecular Biology, Inc.


Zhao J.,First Affiliated Hospital | Wang F.,Key Laboratory of Cellular Physiology | Zhang Y.,First Affiliated Hospital | Jiao L.,First Affiliated Hospital | And 8 more authors.
Circulation | Year: 2013

BACKGROUND - The inhaled anesthetic sevoflurane has been demonstrated to protect against myocardial ischemia/reperfusion (MI/R) injury via mechanisms involving AMP-activated protein kinase (AMPK) and caveolin-3 (Cav-3). However, the relative contributions of AMPK and Cav-3 to sevoflurane preconditioning (SF-PreCon)-mediated cardioprotection and their precise underlying mechanisms of action remain incompletely understood. METHODS AND RESULTS - SF-PreCon (consisting of 3 cycles of 15-minute exposure to 2% sevoflurane before 30 minutes of MI) decreased MI/R injury in wild-type mice (caspase-3 activity, -29.1%; infarct size, -20.2%; and left ventricular end diastolic pressure, -33.8%). In cardiac-specific AMPKα2 dominant-negative overexpressing mice, the cardioprotective effect of SF-PreCon was largely retained (caspase-3 activity, -26.7%; infarct size, -16.7%; and left ventricular end-diastolic pressure, -25.9%; P<0.01). In contrast, SF-PreCon failed to significantly protect Cav-3 knockout mice against MI/R injury (P>0.05). SF-PreCon significantly decreased MI/R-induced superoxide generation in wild-type (-43.6%) and AMPK dominant-negative overexpressing mice (-35.5%; P<0.01) but not in Cav-3 knockout mice. SF-PreCon did not affect nicotinamide adenine dinucleotide phosphate oxidase expression but significantly inhibited cyclooxygenase-2 expression in wild-type (-38.7%) and AMPK dominant-negative overexpressing mice (-35.8%) but not in Cav-3 knockout mice. CONCLUSIONS - We demonstrate for the first time SF-PreCon mediates cardioprotection against MI/R injury via caveolin-3-dependent cyclooxygenase-2 inhibition and antioxidative effects. © 2013 American Heart Association, Inc.


Shi R.,Key Laboratory of Cellular Physiology | Shi R.,Shanxi Medical University | Cui H.,Key Laboratory of Cellular Physiology | Cui H.,Shanxi Medical University | And 25 more authors.
Oncology Letters | Year: 2015

Esophageal squamous cell carcinoma (ESCC) is one of the most common types of cancer in China. Artesunate (ART) is used clinically as an anti‑malarial agent and exhibits potent antiproliferative activity. In addition, ART has demonstrated remarkable antitumor activity, presenting a novel candidate for cancer chemotherapy. However, its effect on ESCC remains unknown. The present study analyzed the antitumor effects of ART in the KYSE‑150 ESCC line by assessing cell proliferation, cell death, cell migration/invasion and the biomechanical properties of ART‑treated KYSE‑150 cells. ART treatment significantly suppressed the proliferation of KYSE‑150 cells in a dose‑ and time‑dependent manner, as assessed by MTT assay. Following treatment with 30 mg/l ART, the cell population in the G 0 /G1 phase and the level of cell apoptosis significantly increased from 54±1.5 to 68.1±0.3%, and from 4.53±0.58 to 12.45±0.62%, respectively. Furthermore, the cell migration and invasion of KYSE‑150 cells treated with 30 mg/l ART was markedly inhibited. The cell membrane and biomechanical properties were investigated using atomic force microscopy, as targets of ART action. ESCC cells treated with 30 mg/l ART exhibited increased adhesive force, increased cytomembrane roughness and reduced elasticity compared with the control group (KYSE‑150 cells without ART treatment). The biomechanical properties of KYSE‑150 cells treated with 30 mg/l ART were similar to those of the SHEE normal human esophageal epithelial cell line. In conclusion, the present study demonstrated that ART may inhibit cell proliferation and migration in ESCC through changes in the biomechanical properties of the ESCC cells. © 2015, Spandidos Publications. All rights reserved.


Cheng X.,Shanxi Medical University | Lu S.-H.,Peking Union Medical College | Cui Y.,Key Laboratory of Cellular Physiology | Cui Y.,Shanxi Medical University
Cancer Letters | Year: 2010

ECRG2 is a novel tumor suppressor gene that shows sequence similarity to KAZAL-type serine protease inhibitor. We have previously demonstrated ECRG2 inhibits migration/invasion of lung cancer PG cells. However, the mechanism by which ECRG2 performs these activities remains unknown. In this study, we found that ECRG2 inhibits proteolysis activity of uPA/plasmin and MMP2, and substantially reduces the ability of HT1080 and HCT-116 cells to invade ECM. Moreover, we demonstrated ECRG2 prevents the cleavage of uPAR, disrupts the association of sD2D3 with FPRL1, and that disruption impairs FPRL1 function. Conversely, depletion of ECRG2 not only markedly increased proteolysis activity of uPA/plasmin and MMP2 but also enhanced the association of uPAR with FPRL1, stimulated cell migration/invasion. Together, our results provide evidence that ECRG2 regulates invasion/migration partly through ECM degradation and uPA/uPAR/FPRL1 pathway, and may represent a novel therapeutic target for cancer. © 2009 Elsevier Ireland Ltd. All rights reserved.


Cui Y.,Peking Union Medical College | Cui Y.,Key Laboratory of Cellular Physiology | Cui Y.,Shanxi Medical University | Bi M.,Peking Union Medical College | And 3 more authors.
International Journal of Oncology | Year: 2010

We previously identified four novel cDNA fragments related to human esophageal cancer. One of the fragments was named esophageal cancer related gene 2 (ECRG2). We report here the molecular cloning, sequencing, and expression of the ECRG2 gene. The ECRG2 cDNA comprises a 258 bp nucleotide sequence which encodes for 85 amino acids with a predicted molecular weight of 9.2 kDa. Analysis of the protein sequence reveals the presence at the N terminus of a signal peptide followed by 56 amino acids with a significant degree of sequence similarity with the conserved Kazal domain which characterizes the serine protease inhibitor family. Pulse-chase experiments showed that ECRG2 protein was detected in both cell lysates and culture medium, indicating that the ECRG2 protein was extracellularly secreted after the post-translational cleavage. In vitro uPA/plasmin activity analysis showed the secreted ECRG2 protein inhibited the uPA/plasmin activity, indicating that ECRG2 may be a novel serine protease inhibitor. Northern blot analysis revealed the presence of the major band corresponding to a size of 569 kb throughout the fetal skin, thymus, esophagus, brain, lung, heart, stomach, liver, spleen, colon, kidney, testis, muscle, cholecyst tissues and adult esophageal mucosa, brain, thyroid tissue and mouth epithelia. However, ECRG2 gene was significantly downregulated in primary esophageal cancer tissues. Taken together, these results indicate that ECRG2 is a novel member of the Kazal-type serine protease inhibitor family and may function as a tumor suppressor gene regulating the protease cascades during carcinogenesis and migration/invasion of esophageal cancer.


Lian S.,Shanxi Medical University | Shi R.,Key Laboratory of Cellular Physiology | Shi R.,Shanxi Medical University | Huang X.,Jinan University | And 14 more authors.
Oncology Reports | Year: 2016

Glioma is one of the most common malignant brain tumors. Current chemotherapy is far from providing satisfactory clinical outcomes for patients with glioma. More efficient drugs are urgently needed. Artesunate (ART) is clinically used as an anti-malarial agent and exhibits potent antiproliferative activity as a traditional Chinese medicine. In addition, ART has been shown to exert a profound cytotoxic effect on various tumor cell lines, presenting a novel candidate for cancer chemotherapy. However, its anticancer effect on glioma by altering cell biomechanical properties remains unclear. The present study aimed to identify the anticancer effects of ART on human glioma SHG44 cells by assessing cell proliferation, migration/invasion, the expression of claudin-1 and the biomechanical properties of ART-treated SHG44 cells. The proliferation of the SHG44 cells was assessed by MTT assay. The cell apoptosis was detected by flow cytometry. For cell migration and invasion assays, the Transwell was used. The expression of the gene claudin-1 was detected by polymerase chain reaction. The cell membrane and biomechanical properties, as targets of ART action, were investigated by atomic force microscopy (AFM). ART significantly inhibited the proliferation of SHG44 cells in a dose- and time-dependent manner. After treatment with 30 mg/l ART, the level of cell apoptosis was significantly increased (from 6.88±0.062 to 23.7±4.16%). Furthermore, the cell migration and invasion abilities of the SHG44 cells were markedly inhibited after treatment with 30 mg/l ART. Compared with the control group (0 mg/l ART), the SHG44 cells treated with 30 mg/l ART exhibited upregulated expression of claudin-1, increased adhesive force (from 2,400±300 to 3,600±500 pN), increased high connection among SHG44 cells, increased cytomembrane roughness (from 0.118±0.011 to 0.269±0.015 μm) and reduced elasticity (from 23±8 to 3.5±1.1 MPa). The present study demonstrated that ART could alter the biomechanical properties of the glioma cells to inhibit cell proliferation, migration and invasion.

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