scholarly journals BUB1 mediation of caspase-independent mitotic death determines cell fate

2007 ◽  
Vol 178 (2) ◽  
pp. 283-296 ◽  
Author(s):  
Yohei Niikura ◽  
Amruta Dixit ◽  
Ray Scott ◽  
Guy Perkins ◽  
Katsumi Kitagawa

The spindle checkpoint that monitors kinetochore–microtubule attachment has been implicated in tumorigenesis; however, the relation between the spindle checkpoint and cell death remains obscure. In BUB1-deficient (but not MAD2-deficient) cells, conditions that activate the spindle checkpoint (i.e., cold shock or treatment with nocodazole, paclitaxel, or 17-AAG) induced DNA fragmentation during early mitosis. This mitotic cell death was independent of caspase activation; therefore, we named it caspase-independent mitotic death (CIMD). CIMD depends on p73, a homologue of p53, but not on p53. CIMD also depends on apoptosis-inducing factor and endonuclease G, which are effectors of caspase-independent cell death. Treatment with nocodazole, paclitaxel, or 17-AAG induced CIMD in cell lines derived from colon tumors with chromosome instability, but not in cells from colon tumors with microsatellite instability. This result was due to low BUB1 expression in the former cell lines. When BUB1 is completely depleted, aneuploidy rather than CIMD occurs. These results suggest that cells prone to substantial chromosome missegregation might be eliminated via CIMD.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ana C. Henriques ◽  
Patrícia M. A. Silva ◽  
Bruno Sarmento ◽  
Hassan Bousbaa

AbstractAntimitotic drugs arrest cells in mitosis through chronic activation of the spindle assembly checkpoint (SAC), leading to cell death. However, drug-treated cancer cells can escape death by undergoing mitotic slippage, due to premature mitotic exit. Therefore, overcoming slippage issue is a promising chemotherapeutic strategy to improve the effectiveness of antimitotics. Here, we antagonized SAC silencing by knocking down the MAD2-binding protein p31comet, to delay mitotic slippage, and tracked cancer cells treated with the antimitotic drug paclitaxel, over 3 days live-cell time-lapse analysis. We found that in the absence of p31comet, the duration of mitotic block was increased in cells challenged with nanomolar concentrations of paclitaxel, leading to an additive effects in terms of cell death which was predominantly anticipated during the first mitosis. As accumulation of an apoptotic signal was suggested to prevent mitotic slippage, when we challenged p31comet-depleted mitotic-arrested cells with the apoptosis potentiator Navitoclax (previously called ABT-263), cell fate was shifted to accelerated post-mitotic death. We conclude that inhibition of SAC silencing is critical for enhancing the lethality of antimitotic drugs as well as that of therapeutic apoptosis-inducing small molecules, with distinct mechanisms. The study highlights the potential of p31comet as a target for antimitotic therapies.


2010 ◽  
Vol 299 (1) ◽  
pp. R215-R221 ◽  
Author(s):  
Zhenfeng Xu ◽  
Jian Zhang ◽  
Karen K. David ◽  
Zeng-Jin Yang ◽  
Xiaoling Li ◽  
...  

Activation of poly(ADP-ribose) polymerase (PARP) and subsequent translocation of apoptosis-inducing factor contribute to caspase-independent neuronal injury from N-methyl-d-aspartate, oxygen-glucose deprivation, and ischemic stroke. Some studies have implicated endonuclease G in the DNA fragmentation associated with caspase-independent cell death. Here, we compared wild-type and endonuclease G null mice to investigate whether endonuclease G plays a role in the PARP-dependent injury that results from transient focal cerebral ischemia. Latex casts did not reveal differences in the cerebral arterial distribution territory or posterior communicating arterial diameter, and the decrease in laser-Doppler flux during middle cerebral artery occlusion was similar in wild-type and endonuclease G null mice. After 90 min of occlusion and 1 day of reperfusion, similar degrees of nuclear translocation of apoptosis-inducing factor and DNA degradation were evident in male wild-type and null mice. At 3 days of reperfusion, infarct volume and neurological deficit scores were not different between male wild-type and endonuclease G null mice or between female wild-type and endonuclease G null mice. These data demonstrate that endonuclease G is not required for the pathogenesis of transient focal ischemia in either male or female mice. Treatment with a PARP inhibitor decreased infarct volume and deficit scores equivalently in male wild-type and endonuclease G null mice, indicating that the injury in endonuclease G null mice remains dependent on PARP. Thus endonuclease G is not obligatory for executing PARP-dependent injury during ischemic stroke.


2002 ◽  
Vol 159 (4) ◽  
pp. 549-555 ◽  
Author(s):  
Jennifer G. DeLuca ◽  
Ben Moree ◽  
Jennifer M. Hickey ◽  
John V. Kilmartin ◽  
E.D. Salmon

Identification of proteins that couple kinetochores to spindle microtubules is critical for understanding how accurate chromosome segregation is achieved in mitosis. Here we show that the protein hNuf2 specifically functions at kinetochores for stable microtubule attachment in HeLa cells. When hNuf2 is depleted by RNA interference, spindle formation occurs normally as cells enter mitosis, but kinetochores fail to form their attachments to spindle microtubules and cells block in prometaphase with an active spindle checkpoint. Kinetochores depleted of hNuf2 retain the microtubule motors CENP-E and cytoplasmic dynein, proteins previously implicated in recruiting kinetochore microtubules. Kinetochores also retain detectable levels of the spindle checkpoint proteins Mad2 and BubR1, as expected for activation of the spindle checkpoint by unattached kinetochores. In addition, the cell cycle block produced by hNuf2 depletion induces mitotic cells to undergo cell death. These data highlight a specific role for hNuf2 in kinetochore–microtubule attachment and suggest that hNuf2 is part of a molecular linker between the kinetochore attachment site and tubulin subunits within the lattice of attached plus ends.


2015 ◽  
Vol 22 (5) ◽  
pp. 759-775 ◽  
Author(s):  
Luca Varinelli ◽  
Dario Caccia ◽  
Chiara C Volpi ◽  
Claudio Caccia ◽  
Maida De Bortoli ◽  
...  

Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that is over-expressed in several human neoplastic cells. When MIF binds its receptor (CD74) and co-receptor (CD44), it initiates signaling cascades that orchestrate cell proliferation and survival, and it can directly modulate the activity of AMPK. These activities indicate that MIF potentially regulates cell survival and metabolism. We found that MIF was primarily co-expressed with CD74 in 16 out of 23 papillary thyroid carcinoma (PTC) and in all the 27 available anaplastic thyroid carcinoma (ATC) biopsy samples. MIF and CD74 were co-expressed in TPC-1 and HTC-C3 cell lines. The selective MIF inhibitor, 4-iodo-6-phenylpyrimidine (4-IPP), blocked MIF/CD74 internalization, activated JNK, and dose-dependently inhibited proliferation inducing apoptosis and mitotic cell death. In two CD74-negative cell lines, NIM-1 and K1, 4-IPP treatment partially reduced proliferation. Coordinated MIF and CD74 expression appeared to confer in tumor cells the plasticity necessary to escape cell cycle regulation, metabolic changes, and stress conditions. MIF/CD74 signaling removal made cells susceptible to apoptosis and mitotic cell death. This finding suggests a possible avenue for targeting DNA endoreduplication, thus preventing the proliferation of therapy-resistant cell subpopulations. This study highlights MIF/CD74 axis as an important player in the biology of aggressive thyroid neoplasms.


2011 ◽  
Vol 300 (6) ◽  
pp. H1997-H2004 ◽  
Author(s):  
Eugene O. Apostolov ◽  
Debarti Ray ◽  
Wilson M. Alobuia ◽  
Marina V. Mikhailova ◽  
Xiaoying Wang ◽  
...  

End-stage kidney disease is a terminal stage of chronic kidney disease, which is associated with a high incidence of cardiovascular disease. Cardiovascular disease frequently results from endothelial injury caused by carbamylated LDL (cLDL), the product of LDL modification by urea-derived cyanate. Our previous data suggested that cLDL induces mitogen-activated protein kinase-dependent mitotic DNA fragmentation and cell death. However, the mechanism of this pathway is unknown. The current study demonstrated that cLDL-induced endothelial mitotic cell death is independent of caspase-3. The expression of endonuclease G (EndoG), the nuclease implicated in caspase-independent DNA fragmentation, was significantly increased in response to cLDL exposure to the cells. The inhibition of EndoG by RNAi protected cLDL-induced DNA fragmentation, whereas the overexpression of EndoG induced more DNA fragmentation in endothelial cells. Ex vivo experiments with primary endothelial cells isolated from wild-type (WT) and EndoG knockout (KO) mice demonstrated that EndoG KO cells are partially protected against cLDL toxicity compared with WT cells. To determine cLDL toxicity in vivo, we administered cLDL or native LDL (nLDL) intravenously to the WT and EndoG KO mice and then measured floating endothelial cells in blood using flow cytometry. The results showed an increased number of floating endothelial cells after cLDL versus nLDL injection in WT mice but not in EndoG KO mice. Finally, the inhibitors of MEK-ERK1/2 and JNK-c-jun pathways decreased cLDL-induced EndoG overexpression and DNA fragmentation. In summary, our data suggest that cLDL-induced endothelial toxicity is caspase independent and results from EndoG-dependent DNA fragmentation.


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 3061-3061
Author(s):  
Michele Baglioni ◽  
Catia Giovannini ◽  
Laura Gramantieri ◽  
Marco Baron Toaldo ◽  
Cristiano Ventrucci ◽  
...  

3061 Background: Sorafenib is the only approved drug for the treatment of the advanced stage of HCC. Although its efficacy has been proven with randomized clinical trials, the clinical benefit seen in overall survival for advanced HCC patients treated with sorafenib could be improved. New molecules or combination of novel targeted agents to improve sorafenib efficacy for advanced stage HCC patients are needed. Notch genes are a family of receptors involved in many cell fate regulations, their expression has been found altered in many tumors, including HCC. The aim of this study was to study the combination of sorafenib and Notch3 signaling inhibition to improve sorafenib’s therapeutic effect. Methods: HepG2 and Huh7 cellular models were used for Notch3 stable silencing by retroviral introduction of specific interfering RNAs Xenograft models in both Notch3 stable shRNA cell lines have been developed using NOD/SCID mice. Animals bearing tumors were treated with 60 mg/kg of sorafenib for 21 consecutive days. Notch3, p21 and pGSK3βSer9 protein expression were also analyzed in 20 human HCCs. Results: Notch3 silencing (shN3) in HuH7 and HepG2 cell lines treated with sorafenib showed an increase in cell death (3.8 to 5 fold increase) when shN3 cell lines were compared with their relative controls (GL2). A difference in tumor growth was observed between GL2 negative control vs shN3 xenografts in both HepG2 and Huh7 after 21 days of sorafenib treatment. Two tailed student’s t test (shN3 vs GL2) P=0,04 and P=0,01 for Huh7 and HepG2 respectively. Molecular investigations have shown the involvement of p21 and GSK3β in the enhanced response to sorafenib in Notch 3 silenced models. A significant inverse correlation between Notch3 and pGSK3βSer9 proteins accumulation (Spearman ρ= -0.666) (p < 0.01) and a direct correlation between Notch3 and p21 proteins expression (Spearman ρ= 0.681) (p < 0.01) was found in HCC samples obtained from patients. Conclusion: Our preclincal findings outline the effect of combined Notch3 inhibition and sorafenib. The molecular mechanisms responsible for sorafenib induced cell death associated with Notch3 silencing relays on inhibition of p21/CDKN1A and GSK3βSer9. This study is supported by a grant from Bayer Healthcare, Italy.


2015 ◽  
Vol 20 (5) ◽  
Author(s):  
Qingpan Bu ◽  
Jianhui Wang ◽  
Yi Zheng ◽  
Yingying Zou ◽  
Min Wei

AbstractMacrophage galactose-type lectin (MGL) participates in the regulation of T cell apoptosis, but the exact death pathway remains unclear. Here, we demonstrated that MGL-induced T cell death occurs in a caspaseindependent manner. Furthermore, MGL treatment triggers the translocation of endonuclease G (EndoG) and apoptosis-inducing factor (AIF) from the mitochondria to the nucleus. Because galectin-1 (Gal-1) can also initiate similar mitochondrial events, we speculate that this death pathway may be widely used by the lectin family.


2017 ◽  
Vol 187 (5) ◽  
pp. 562 ◽  
Author(s):  
Pelagia Tsoutsou ◽  
Alessandro Annibaldi ◽  
David Viertl ◽  
Jonathan Ollivier ◽  
Franz Buchegger ◽  
...  

2020 ◽  
Author(s):  
Arindam Mondal ◽  
Rachel NeMoyer ◽  
Elaine Langenfeld ◽  
Danea Glover ◽  
Michael Scott ◽  
...  

Abstract Background: Bone morphogenetic protein (BMP) is an evolutionarily conserved morphogen that is reactivated in lung carcinomas. BMP receptor inhibitors promote cell death of lung carcinomas by mechanisms not fully elucidated. The studies here reveal novel mechanisms by which the “survivin” inhibitor Ym155 in combination with the BMP receptor inhibitor JL5 synergistically induces death of lung cancer cells. Methods: This study examines the mechanism by which Ym155 in combination with JL5 downregulates BMP signaling and induces cell death of non-small cell lung carcinoma (NSCLC) cell lines. Validation experiments were performed on five passage 0 primary NSCLC cell lines. Results: We found that Ym155, which is reported to be a survivin inhibitor, potently inhibits BMP signaling by causing BMPR2 mislocalization into the cytoplasm and its decreased expression. The combination of Ym155 and the BMP receptor inhibitor JL5 synergistically causes the downregulation of BMP Smad-1/5 dependent and independent signaling and the induction of cell death of lung cancer cell lines and primary lung tumors. Cell death involves the nuclear translocation of apoptosis inducing factor (AIF) from the mitochondria to the nucleus. This causes DNA double stranded breaks independent of caspase activation, which occur only when JL5 and Ym155 are used in combination. Knockdown of BMPR2 together with Ym155 also induced AIF localization to the nucleus. Conclusions: These studies suggest that inhibition of BMPR2 together with Ym155 can induce AIF caspase-independent cell death. AIF caspase-independent cell is an evolutionarily conserved cell death pathway that has never been targeted to induce cell death in cancer cells. These studies provide mechanistic insight of how to target AIF caspase-independent cell death using BMP inhibitors.


Sign in / Sign up

Export Citation Format

Share Document