1%. It is known that apoptosis is the programmed death of cells, a variety of studies have revealed that the uncontrolled growth of neoplasms is not only the cause of the over growth but also the loss of natural apoptosis [32, 33]. Therefore, the antibody that is capable of inducing cancer cells apoptosis would be helpful for cancer treatment. In this study, transmission electron microscope, TUNEL staining and flow cytometry were used to detect apoptosis, and the results
demonstrated that ChA21 could induce apoptosis on SK-OV-3 cells both in vitro and in vivo. Hence, we can deduce that the growth inhibition of ChA21 on SK-OV-3 cells was at least partially contributed by its role of apoptosis induction. To further investigate the possible Ro-3306 molecular mechanism of apoptosis induced by ChA21, apoptosis-regulated proteins Bcl-2 and Bax were detected by immunocytochemistry and immunohistochemistry. Tucidinostat in vitro It is known that Bcl-2 gene acts to inhibit apoptosis, while Bax gene induces apoptosis. The imbalanced expression of Bcl-2 to Bax protein influences
the apoptosis of cells stimulated by either external or internal factors [34, 35]. Recent studies reported that HER-2 over-expression is accompanied by up-regulation of Bcl-2 and down-regulation of Bax [36, 37]. Our results showed that after exposure to ChA21, Bcl-2 expression of SK-OV-3 cells was decreased, and Bax expression was increased, resulting in a decrease in Bcl-2/Bax value. Therefore, we concluded that one of the pathways of ChA21 inducing apoptosis might up-regulate Bax expression, and learn more down-regulate Bcl-2 expression. In conclusion, the results indicate that ChA21 could inhibit growth and induce apoptosis of human ovarian cancer cell line SK-OV-3 via regulating the balance between Bax and Bcl-2. It suggests that ChA21 might be a new promising candidate in the treatment of HER-2 over-expressed ovarian cancers.
In addition, the mechanisms of ChA21 inhibits SK-OV-3 cells growth not only via inducing apoptosis, but also by interfering with HER-2 heterodimerization mafosfamide and affecting HER-2 signaling pathway, and further study is needed. Acknowledgements This work was supported by the National High Technology Program of China (“”863 project”", No. 2004AA215260) and Anhui Province Nature Science Foundation (No. 03043701) and National Science Foundation of China (30873047). References 1. Jemal A, Siegel R, Ward E, et al.: Cancer statistics. Cancer Journal for Clinicians 2008, 58:71–96.CrossRef 2. Breedlove G, Busenhart C: Screening and detection of ovarian cancer. Journal of Midwifery & Women’s Health 2005, 50:51–54.CrossRef 3. Bast RC, Hennessy B, Mills GB: The biology of ovarian cancer: new opportunities for translation. Nature Reviews Cancer 2009, 9:415–428.PubMedCrossRef 4. Carpenter G: Receptors for epidermal growth factor and other polypeptide mitogens. Annu Rev Biochem 1987, 56:881–914.PubMedCrossRef 5.