Staurosporine-induced death of MCF-7 human breast cancer cells: a distinction between caspase-3-dependent steps of apoptosis and the critical lethal lesions

2003 ◽  
Vol 283 (2) ◽  
pp. 135-145 ◽  
Author(s):  
Liang-yan Xue ◽  
Song-mao Chiu ◽  
Nancy L Oleinick
2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Saeed Esmaeili-Mahani ◽  
Farzaneh Falahi ◽  
Mohammad Mehdi Yaghoobi

Thymus caramanicus Jalasis one of the species of thymus that grows in the wild in different regions of Iran. Traditionally, leaves of this plant are used in the treatment of diabetes, arthritis, and cancerous situation. Therefore, the present study was designed to investigate the selective cytotoxic and antiproliferative properties ofThymus caramanicusextract (TCE). MCF-7 human breast cancer cells were used in this study. Cytotoxicity of the extract was determined using MTT and neutral red assays. Biochemical markers of apoptosis (caspase 3, Bax, and Bcl-2) and cell proliferation (cyclin D1) were evaluated by immunoblotting. Vincristine was used as anticancer control drug in extract combination therapy. The data showed that incubation of cells with TCE (200 and 250 μg/mL) significantly increased cell damage, activated caspase 3 and Bax/Bcl2 ratio. In addition, cyclin D1 was significantly decreased in TCE-treated cells. Furthermore, concomitant treatment of cells with extract and anticancer drug produced a significant cytotoxic effect as compared to extract or drugs alone. In conclusion, thymus extract has a potential proapoptotic/antiproliferative property against human breast cancer cells and its combination with chemotherapeutic agent vincristine may induce cell death effectively and be a potent modality to treat this type of cancer.


2003 ◽  
Vol 17 (10) ◽  
pp. 2002-2012 ◽  
Author(s):  
Olga A. Sukocheva ◽  
Lijun Wang ◽  
Nathaniel Albanese ◽  
Stuart M. Pitson ◽  
Mathew A. Vadas ◽  
...  

Abstract Current understanding of cytoplasmic signaling pathways that mediate estrogen action in human breast cancer is incomplete. Here we report that treatment with 17β-estradiol (E2) activates a novel signaling pathway via activation of sphingosine kinase (SphK) in MCF-7 breast cancer cells. We found that E2 has dual actions to stimulate SphK activity, i.e. a rapid and transient activation mediated by putative membrane G protein-coupled estrogen receptors (ER) and a delayed but prolonged activation relying on the transcriptional activity of ER. The E2-induced SphK activity consequently activates downstream signal cascades including intracellular Ca2+ mobilization and Erk1/2 activation. Enforced expression of human SphK type 1 gene in MCF-7 cells resulted in increases in SphK activity and cell growth. Moreover, the E2-dependent mitogenesis were highly promoted by SphK overexpression as determined by colony growth in soft agar and solid focus formation. In contrast, expression of SphKG82D, a dominant-negative mutant SphK, profoundly inhibited the E2-mediated Ca2+ mobilization, Erk1/2 activity and neoplastic cell growth. Thus, our data suggest that SphK activation is an important cytoplasmic signaling to transduce estrogen-dependent mitogenic and carcinogenic action in human breast cancer cells.


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