1. Institute of virology and AIDS research, The first hospital of Jilin University, Changchun 130021, P. R. China;
2. Department of Thyroid Surgery, The First Hospital of Jilin University, Changchun 130021, P. R. China;
3. Acupunture department, The affiliated hospital to Changchun University of Chinese Medicine, Changchun 130021, P. R. China;
4. Department of Biotechnology, College of Animal Science and Veterinary Medicine, Jilin University, Changchun 130062, P. R. China;
5. Medicinal chemistry, Changchun University of Chinese Medicine, Changchun 130021, P. R. China;
6. Key Laboratory of Natural Medicine and Immuno-Engineering, Henan University, Hennan, Kaifeng 475004, P. R. China;
7. Tumor department of Hematology, the 208th Hospital of PLA, Changchun, 130062, P. R. China.
* Jing-hua Yu, Gui-bin Zheng and Chun-yu Liu are co-first authors.
Objective: Dracorhodin perchlorate (DP) was a synthetic analogue of the antimicrobial anthocyanin red pigment dracorhodin. It was reported that DP could induce apoptosis in human prostate cancer, human gastric tumor cells and human melanoma, but the cytotoxic effect of DP on human breast cancer was not investigated. This study would investigate whether DP was a candidate chemical of anti-human breast cancer.
Methods: The MTT assay reflected the number of viable cells through measuring the activity of cellular enzymes. Phase contrast microscopy visualized cell morphology. Fluorescence microscopy detected nuclear fragmentation after Hoechst 33258 staining. Flowcytometric analysis of Annexin V-PI staining and Rodamine 123 staining was used to detect cell apoptosis and mitochondrial membrane potential (MMP). Real time PCR detected mRNA level. Western blot examined protein expression.
Results: DP dose and time-dependently inhibited the growth of MCF-7 cells. DP inhibited MCF-7 cell growth through apoptosis. DP regulated the expression of Bcl-2 and Bax, which were mitochondrial pathway proteins, to decrease MMP, and DP promoted the transcription of Bax and inhibited Bcl-2. Apoptosis-inducing factor (AIF) and cytochrome c which localized in mitochondrial in physiological condition were released into cytoplasm when MMP was decreased. DP activated caspase-9, which was the downstream of mitochondrial pathway. Therefore DP decreased MMP to release AIF and cytochrome c into cytoplasm, further activating caspase 9, lastly led to apoptosis.
Conclusion: Therefore DP was a candidate for anti-breast cancer, DP induced apoptosis of MCF-7 through mitochondrial pathway.
Keywords: dracorhodin perchlorate, apoptosis, mitochondrial pathway