Abstract 4910: Apoptotic effects of curcumin and bleomycin alone or in combination on malignant testicular germ cells
Authors: Cort Aysegul , Kucuksayan Ertan , Ozben Tomris 
Published: August 2012

Aims: Testicular cancer is the most common cancer among young men of reproductive age. Bleomycin is a frequently used drug for the treatment of several malignancies and is part of the chemotherapy protocols in testicular cancer, but side effects are common. Bleomycin increases oxidative stress which has been shown to induce apoptosis in cancer cells. Curcumin (diferuloylmethane), an active component of the spice turmeric, has been demonstrated to induce apoptosis in several types of malignancies. However, no study has been carried out so far to elucidate its possible anticancer activity and interaction with Bleomycin in testicular cancer cells. Methods: In this study, we investigated the effects of Curcumin and Bleomycin alone or in combination on apoptosis-signalling-pathways. We determined the cytotoxic effect of Bleomycin and Curcumin on NTera-2 (NT2) cells using 3-(4,5) dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and measured apoptosis signalling pathway markers such as Caspase-3, Caspase-8, Caspase-9 activities and Bcl-2, Bax and Cyt-c levels in NT2 cells incubated with Bleomycin in the presence or absence of Curcumin. Results: Median lethal dose (LD50) of Bleomycin on NT2 cell viability as 400 μg/ml after an incubation of 24 h and LD50 of Curcumin as 20 μM. Treatment with Bleomycin (400 μg/ml) and Curcumin (20 μM) alone for 24 h caused 3.2-fold and 3-fold increase in caspase-3 activity, 3.4-fold and 2-fold increase in caspase-8 activity, 2.9-fold and 2.8 fold increase in caspase-9 activities respectively. These treatments alone also caused 2-fold increase in Bax and 2-fold increase in cytoplasmic Cyt-c levels while leading 2-fold decrease in Bcl-2 levels. Combination of Curcumin with Bleomycin induced Caspase-3,-8,-9 activities more than their separate effects in NT2 cells. Specifically combination of Curcumin (20 μM) with Bleomycin (400 μg/ml) induced 4.2-fold increase in Caspase-3, 4.3-fold increase in caspase-8 activity, 4-fold increase in caspase-9 activity, 3-fold increase in cytoplasmic Cyt-c levels and 3-fold decrease in Bcl-2 levels.Conclusion: Bleomycin has proven to be an essential component of the cisplatin-based chemotherapy regimens, used in the treatment of testicular cancer. However, the use of Bleomycin is limited because of Bleomycin-induced pneumonitis, a complication occurring in approximately 10% of patients treated with Bleomycin and fatal in approximately 10% of the cases. Our observations suggest that the effects of Bleomycin on apoptosis-signalling-pathways were improved by Curcumin. Co-administration of Bleomycin with Curcumin could be a new strategy to use less dosage of Bleomycin and prevent patients from Bleomycin-induced side effects.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4910. doi:1538-7445.AM2012-4910