scholarly journals The Fanconi anemia complementation group C protein corrects DNA interstrand cross-link-specific apoptosis in HSC536N cells

Blood ◽  
1996 ◽  
Vol 88 (6) ◽  
pp. 2298-2305 ◽  
Author(s):  
UK Marathi ◽  
SR Howell ◽  
RA Ashmun ◽  
TP Brent
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Fanconi Anemia ◽  
Complementation Group ◽  
Cross Linking ◽  
Wild Type ◽  
Cross Link ◽  
Cycle Arrest ◽  
Protein Functions ◽  
Induced Apoptosis

Fanconi anemia (FA) cells are hypersensitive to cytotoxicity, cell cycle arrest, and chromosomal aberrations induced by DNA cross-linking agents, such as mitomycin C (MMC) and nitrogen mustard (HN2). Although MMC hypersensitivity is complemented in a subset of FA cells (complementation group C [FA-C]) by wild-type FAC cDNA, the cytoprotective mechanism is unknown. In the current study, we tested the hypothesis that FAC protein functions in the suppression of DNA interstand cross-link (ISC)-induced cell cycle arrest and apoptosis. Comparison of HN2-induced cell cycle arrest and apoptosis with those of its non-cross-linking analogs, diethylaminoethyl chloride and 2- dimethylaminoethyl chloride, delineated the DNA ISC specificity of FAC- mediated cytoprotection. Overexpression of wild-type FAC cDNA in FA-C lymphoblasts (HSC536N cell line) prevented HN2-induced growth inhibition, G2 arrest, and DNA fragmentation that is characteristic of apoptosis. In contrast cytoprotection was not conferred against the effects of the non-cross-linking mustards. Our data show that DNA ISCs induce apoptosis more potently than do DNA monoadducts and suggest that FAC suppresses specifically DNA ISC-induced apoptosis in the G2 phase of the cell cycle.

Inhibition of p53-MDM2 Interaction by Small-Molecule Antagonist of MDM2 Effectively Induces Apoptosis in Leukemias.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2536-2536
Author(s):  
Kensuke Kojima ◽  
Marina Konopleva ◽  
Masato Shikami ◽  
Maria Cabreira-Hansen ◽  
C. Ellen Jackson ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Annexin V ◽  
Cell Number ◽  
Leukemia Cells ◽  
P53 Mutations ◽  
Wild Type ◽  
Cycle Arrest ◽  
Wild Type P53 ◽  
Induced Apoptosis

Abstract Alteration of the p53 gene is one of the most frequent events in human tumorigenesis and about 50% of all solid tumors have been reported to carry p53 mutations. The inactivation of p53 in cancer has been associated with poor survival, refractory disease and chemoresistance. p53 mutations rarely occur in hematopoietic malignancies. Instead, MDM2 which is a principal cellular antagonist of p53, is overexpressed in the majority of leukemias. Recently, potent and selective small-molecule antagonists of MDM2, Nutlins, have been identified (Science303:844–888, 2004). Nutlins bind MDM2 in the p53-binding pocket and activate the p53 pathway in human cancer cells with wild-type p53, leading to cell cycle arrest, apoptosis, and growth inhibition of human tumor xenografts in nude mice. In this study, we investigated the potential antileukemic activity of the MDM2 antagonist. Treatment of wild-type p53 OCI-AML-3 cells with 5 μM of an active compound (Nutlin-3a) induced cell cycle arrest and apoptosis as evidenced by flow-cytometric analysis (51% reduction of S-phase at 12 h, 27% sub-G1 DNA content and 57% Annexin V positivity at 48 h). Similar proapoptotic effects were observed in MOLM-13 cells which have wild-type p53, but not in p53-null (HL-60 and U937) or mutant p53 (Raji, Jurkat and NB-4) cells. Nutlin-3a induced apoptosis in a dose- and time-dependent manner, and induced maximal effect on cell cycle arrest at 1 μM. Western blot analysis showed that in OCI-AML-3 cells, wild-type p53 accumulated at 1 h after exposure to Nutlin-3a. Increased levels of MDM2, p21 and Noxa proteins were observed at 1 to 3h. This resulted in cleavage of caspase-9 followed by cleavage of caspase-3. A pharmacologic interaction study between MDM2 inhibitor and Ara-C using a fixed-ratio (1:1) experimental design showed highly synergistic cell growth inhibition (CI = 0.44) and induction of apoptosis (CI = 0.83) in OCI-AML-3 cells. Initial studies conducted in primary leukemia cells demonstrated that Nutlin-3a induced apoptosis in 4 of 5 AML samples tested (68–97% Annexin V induction and 65–93% cell number reduction) and 2 CLL samples (>50% Annexin V induction and 37% and 58% cell number reduction). Since MDM2 protein is overexpressed and p53 is not mutated in the majority of primary leukemia cells, this approach may have therapeutic utility in leukemias.

Synergistic Effect of α-Solanine and Cisplatin Induces Apoptosis and Enhances Cell Cycle Arrest in Human Hepatocellular Carcinoma Cells

2020 ◽  
Vol 19 (18) ◽  
pp. 2197-2210 ◽  
Author(s):  
Sherien M. El-Daly ◽  
Shaimaa A. Gouhar ◽  
Amira M. Gamal-Eldeen ◽  
Fatma F. Abdel Hamid ◽  
Magdi N. Ashour ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Cycle ◽  
Synergistic Effect ◽  
Cell Cycle Arrest ◽  
Combination Treatment ◽  
Carcinoma Cells ◽  
Cell Growth Inhibition ◽  
Cycle Arrest ◽  
Induced Apoptosis ◽  
Human Hepatocellular Carcinoma Cells

Aim: The clinical application of cisplatin is limited by severe side effects associated with high applied doses. The synergistic effect of a combination treatment of a low dose of cisplatin with the natural alkaloid α-solanine on human hepatocellular carcinoma cells was evaluated. Methods: HepG2 cells were exposed to low doses of α-solanine and cisplatin, either independently or in combination. The efficiency of this treatment modality was evaluated by investigating cell growth inhibition, cell cycle arrest, and apoptosis enhancement. Results: α-solanine synergistically potentiated the effect of cisplatin on cell growth inhibition and significantly induced apoptosis. This synergistic effect was mediated by inducing cell cycle arrest at the G2/M phase, enhancing DNA fragmentation and increasing apoptosis through the activation of caspase 3/7 and/or elevating the expression of the death receptors DR4 and DR5. The induced apoptosis from this combination treatment was also mediated by reducing the expression of the anti-apoptotic mediators Bcl-2 and survivin, as well as by modulating the miR-21 expression. Conclusion: Our study provides strong evidence that a combination treatment of low doses of α-solanine and cisplatin exerts a synergistic anticancer effect and provides an effective treatment strategy against hepatocellular carcinoma.

Mechanisms of sulindac-induced apoptosis and cell cycle arrest

2005 ◽  
Vol 219 (1) ◽  
pp. 15-25 ◽  
Author(s):  
B JUNG ◽  
V BARBIER ◽  
H BRICKNER ◽  
J WELSH ◽  
A FOTEDAR ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Cycle Arrest ◽  
Induced Apoptosis

scholarly journals Betulinic Acid Restricts Human Bladder Cancer Cell Proliferation In Vitro by Inducing Caspase-Dependent Cell Death and Cell Cycle Arrest, and Decreasing Metastatic Potential

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1381
Author(s):  
So Young Kim ◽  
Hyun Hwangbo ◽  
Min Yeong Kim ◽  
Seon Yeong Ji ◽  
Da Hye Kim ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Bladder Cancer ◽  
Cell Cycle Arrest ◽  
Cancer Cells ◽  
Human Bladder Cancer ◽  
Human Bladder ◽  
Cycle Arrest ◽  
Bladder Cancer Cells ◽  
Induced Apoptosis ◽  
Human Bladder Cancer Cells

Betulinic acid (BA) is a naturally occurring pentacyclic triterpenoid and generally found in the bark of birch trees (Betula sp.). Although several studies have been reported that BA has diverse biological activities, including anti-tumor effects, the underlying anti-cancer mechanism in bladder cancer cells is still lacking. Therefore, this study aims to investigate the anti-proliferative effect of BA in human bladder cancer cell lines T-24, UMUC-3, and 5637, and identify the underlying mechanism. Our results showed that BA induced cell death in bladder cancer cells and that are accompanied by apoptosis, necrosis, and cell cycle arrest. Furthermore, BA decreased the expression of cell cycle regulators, such as cyclin B1, cyclin A, cyclin-dependent kinase (Cdk) 2, cell division cycle (Cdc) 2, and Cdc25c. In addition, BA-induced apoptosis was associated with mitochondrial dysfunction that is caused by loss of mitochondrial membrane potential, which led to the activation of mitochondrial-mediated intrinsic pathway. BA up-regulated the expression of Bcl-2-accociated X protein (Bax) and cleaved poly-ADP ribose polymerase (PARP), and subsequently activated caspase-3, -8, and -9. However, pre-treatment of pan-caspase inhibitor markedly suppressed BA-induced apoptosis. Meanwhile, BA did not affect the levels of intracellular reactive oxygen species (ROS), indicating BA-mediated apoptosis was ROS-independent. Furthermore, we found that BA suppressed the wound healing and invasion ability, and decreased the expression of Snail and Slug in T24 and 5637 cells, and matrix metalloproteinase (MMP)-9 in UMUC-3 cells. Taken together, this is the first study showing that BA suppresses the proliferation of human bladder cancer cells, which is due to induction of apoptosis, necrosis, and cell cycle arrest, and decrease of migration and invasion. Furthermore, BA-induced apoptosis is regulated by caspase-dependent and ROS-independent pathways, and these results provide the underlying anti-proliferative molecular mechanism of BA in human bladder cancer cells.

Sign in / Sign up

Export Citation Format

Share Document