Study On Panaxadial Saponins Inhibit The Growth Of Hela Cells

Cervical cancer is one of the most common malignant tumors, and is the second largest incidence of tumors in women, second only to breast cancer. Approximately 250 thousand women die from this disease every year. Human papilloma virus(HPV) is the main reason which causes cervical cancer. At present, the main treatment of cervical cancer is surgery, radiotherapy and chemotherapy, but every treatment dose not cure cervical cancer.Panax Notoginseng is a traditional expensive Chinese medicine, mainly come from Yunnan, Guangxi and Sichuan province. Panax Notoginseng, also known as pseudo-ginseng, Jin bu huan, Kaihua Panax Notoginseng, and ginseng Panax Notoginseng, etc. It could lower blood pressure, prevent atherosclerosis, improve immunity, have the anti-tumor, anti-oxidant and anti-aging effects. Panax Notoginseng is the main active component, which could be divided into Panaxadial Saponins(PDS) and Panaxatrial Saponins(PTS).Thioredoxin is a small molecule protein, the molecular weight is 12 KDa, which is present in many different prokaryotes and eukaryotes. Trx contains a conserved redox catalytic site:Cys-Gly-Pro-Cys.The thioredoxin system comprises Trx and thioredoxin reductase plus NADPH. With the latter reducing the active site disulfide of oxidized Trx(Trx-S2) to a dithiol(Trx-(SH)2). Trx regulation of the activity of many transcription factors, such as NF-κB, AP-1 and SP-1 and so on. The expresion of Trx is increased in many human cancer tissues. Therefore, it could serve as an important target for the treatment of cancer.Cell cycle progression is regulated by cyclins and cyclin-dependent protein kinases (CDKs). Cyclin D1 is an important cell cycle regulatory protein, which is a major regulator of G1/S phase.Our researches focus on cervical cancer cell lines Hela cells, and detect the effect of growth and survival of Hela cells treated by PDS. We used trypan blue exclusion staining and MTT experiment, and found that PDS inhibited the growth of Hela cells in dose- dependent manner and time- dependent manner. Our LDH experiment and flow cytometry confirmed that a certain dose of PDS could induce apoptosis in Hela cells.In the end, our studies focus on the molecular mechanism about PDS inhibit the growth of Hela cells and induce apoptosis of Hela cells. We use the gradient concentration of PDS (0μg/ml,200μg/ml,400μg/ml,800μg/ml) treat with Hela cells for 24 h, and detect Trx and thioredoxin-binding protein-2 (TBP-2) mRNA expression by Real-Time PCR, the results showed that PDS has no significant effect on the mRNA expression levels of Trx and TBP-2. Western Blot detected protein expression of Trx and of CyclinDl. The results indicated that PDS can reduce the protein expression level of Trx and CyclinD1 in dose-dependent manner. We use PDS (400μg/ml) and proteasome inhibitor MG132 (25μM) treatment Hela cells for 12 h, Western Blot Detected the protein expression of thioredoxin and CyclinD1. The results showed that PDS down-regulated the protein expression CyclinD1 in a post-transcriptional mechanisms, while the PDS reduced the protein expression of thioredoxin does not involve post-transcriptional mechanisms.These date suggest that PDS reduced Trx protein levels may be through a post-transcriptional mechanism. We use PDS (400μg/ml) and the p38 MAPK inhibitor SB203580 (10μM) dealing with Hela cells for 24 h, the LDH experimental results show that:SB203580 does not inhibit apoptosis induced by PDS, which suggest that PDS could induced apoptosis not through the p38 MAPK pathway.