Caspase mediated enhanced apoptotic action of cyclophosphamide- and resveratrol-treated MCF-7 cells.
Cyclophosphamide (CPA) is a widely used chemotherapeutic drug for neoplasias. It is a DNA and protein alkylating agent having a broad spectrum of activity against a variety of neoplasms including breast cancer. The therapeutic effectiveness of CPA is limited by the high-dose hematopoietic, renal, and cardiac toxicity that accompanies the systemic distribution of liver-derived activated drug metabolites. The present study examines the potential of combining resveratrol (RES) with CPA and aims to increase the understanding of the mechanism of cell killing. Interestingly, we found that RES significantly enhances the caspase-mediated cytotoxic activity of CPA on MCF-7 cells in vitro. RES at 50 microM decreases the IC(50) value of CPA from 10 to 5 mM. FACS data reveals CPA or RES alone mediated G0/G1 and S phase arrest, while the combination of these drugs released both the arrests and results in an increase in the sub G0/G1 peak. Additional analyses indicated the significant up-regulation (P = 0.001) of tumor suppressor p53 and p53-regulated pro-apoptotic Bax and Fas in MCF-7 cells following CPA treatment in combination with RES, which may contribute to the enhancement of the antitumor effect of CPA. Furthermore, downregulation of anti-apoptotic Bcl-2 (P = 0.001) was observed in MCF-7 cells treated with CPA with or without RES when compared to untreated MCF-7. These results suggest the possibility of a new combination chemotherapeutic regimen leading to improvements in the treatment of breast cancer.
Singh
Neetu
N
Genotoxicity Laboratory, Toxicology Division, Central Drug Research Institute, India. neetuaashi@yahoo.com
Nigam
Manisha
M
Ranjan
Vishal
V
Sharma
Ramesh
R
Balapure
Anil Kumar
AK
Rath
Srikanta Kumar
SK
D017304:Annexin A5 / Q000378:metabolism; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology*; D051017:Apoptosis Regulatory Proteins / Q000096:biosynthesis / Q000235:genetics; D015153:Blotting, Western; D061945:Caspase Inhibitors; D020169:Caspases / Q000502:physiology*; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003124:Colorimetry; D003520:Cyclophosphamide / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D006801:Humans; D000077185:Resveratrol; D013267:Stilbenes / Q000494:pharmacology*
D017304:Annexin A5; D016588:Anticarcinogenic Agents; D018906:Antineoplastic Agents, Alkylating; D051017:Apoptosis Regulatory Proteins; D061945:Caspase Inhibitors; D004791:Enzyme Inhibitors; D005456:Fluorescent Dyes; D013267:Stilbenes; D003520:Cyclophosphamide; D020169:Caspases; D016650:Fluorescein-5-isothiocyanate; D000077185:Resveratrol