|
Chemotherapy is a common means of clinical treatment of malignant tumors. With the in-depth study of the mechanisms of tumor pathology, chemotherapy drugs, side effects are also after the structure - the efficacy analysis, drug molecular targets and mechanisms explore constantly being improved. Derived from plants and animals, and a variety of natural products of microorganisms found the active ingredients, including a huge treasure of anticancer drugs. Such as camptothecin, vincristine, natural plant polyphenols (such as polyphenols, flavonoids) paclitaxel, especially paclitaxel and its semi-synthetic docetaxel in recent years, is widely used in clinical antineoplastic agents, its wide spectrum, low toxicity, efficacy and good for the treatment of a variety of tumors, showing the great potential of natural products as anticancer drugs [1-6]. Prostate cancer (prostate cancers, PCa) as a high incidence of Europe and the United States, the high mortality rate of malignant tumors, and the incubation period is long, complex biological characteristics. Especially formed relapse after endocrine therapy for hormone-refractory prostate cancer (Hormone refractory prostate cancer, HRPC), against endocrine therapy, transfer deterioration, difficult to cure, the prognosis is poor, with high mortality, lack of effective treatment, so the relevant basic research and clinical treatment of PCa has been great concern. Docetaxel for late HRPC treatment by stabilizing microtubules and induce apoptosis and to play a role, is the only confirmed HRPC can significantly extend the lifetime of the drug in patients with HRPC chemotherapy has made new progress, therefore, chemotherapy may be treatment of HRPC effective strategy, the study found that the effect of the chemotherapy drugs is imperative. In recent years, the incidence of prostate cancer in the country was a clear upward trend, and make full use of our natural drugs for the prevention and treatment of prostate cancer, independent innovation, research and development of drugs to produce good social and economic benefits. Bibenzyl compounds as a new class of plant antibiotics, widespread in the moss, orchids, has anti-bacterial, anti-viral cytotoxic activity, but the the bioactive mechanism study reported [7-13]. The subjects of a share of more than about 50 liverworts bibenzyl compounds for screening of anti-tumor activity, found that there are different levels of such compounds antitumor activity, and there is a certain amount of structure-activity relationship. We selected three compounds with certain structural characteristics as the focus leaves moss prime C (Riccardin C, Ric) Pakyonol (Pak), the feather moss prime E the (Plagiochin E, Pla) to study the impact of different tumor cell proliferation . Cell proliferation experiment results show that (1) Ric Pak Pla compounds the human kidney epithelial 293 cells, breast cancer MCF-7 cells, hormone-dependent prostate cancer LNCaP, androgen-independent prostate cancer PC3 and DU145 have much to do good inhibition, its inhibition with increasing dose and enhanced. The especially significant inhibition of PC3 cells in a dose, dose-dependent, Ric, Pak and Pla drugs after 48h ID50 for 3.22μMol / L 7.98μMol / L, and 5.99μMol / L. (2) on HepG2 cells, leukemia K562 cells a certain extent, also in a dose-dependent manner, significantly high concentrations inhibition. (3) of the normal human retinal pigment epithelial cells (hTERT-RPE1) cell proliferation, Ric, Pak and Pla drugs after 48h ID50 were 65.97μMol / L, 58.62, and 57.09μMol / L. Androgen-independent prostate cancer cell proliferation is not dependent on hormones, and not sensitive to chemical drugs, is not easy to apoptosis, a high degree of malignancy. Bibenzyl-based compound on the proliferation of such cells was significantly inhibited, indicating that it has a good potential for research and development. Therefore, we focused on the hormone-independent prostate cancer PC3 cells and further validate of three Bibenzyls compounds antitumor activity. We first determined by measuring the content of lactate dehydrogenase in the cell culture medium Ric Pak and PLA toxicity of PC3 cells, as compared with the control group, three compounds have different levels of cytotoxic activity, and the cytotoxicity of Ric Pak cytotoxic min. Closely related to cell proliferation and cell cycle, we further analyze bibenzyl compounds inhibit PC3 cell cycle, the results show that Ric compound to arrest the cell cycle at the G2 / M phase Pak compound to arrest cells in G0/G1 phase, while low concentration of Pla (5μMol / L), the cells arrested in G0/G1 phase, high concentrations of Pla (10μMol / L) cell cycle arrest in the S phase, that Bibenzyls compounds inhibit cell proliferation associated with cell cycle resistance stagnation. In addition, PC3 cells treated by the three compounds, streaming analysis showed hypodiploid peak, indicating that the three compounds have different levels of induced apoptosis, apoptosis rate with increasing concentration and l high. Morphological changes by Giemsa staining PI/Hochest33342 staining and Annexin V / PI staining to determine of bibenzyl class compounds induced apoptosis, the results clearly show the characteristics of apoptotic cells, such as chromatin aggregation and apoptotic bodies, phosphatidylserine valgus, etc., and with the increase of drug concentration, the degree of apoptosis enhancement. Finally, the topics discussed the three pairs Bibenzyls compounds on the expression of apoptosis-related proteins, results showed, Ric, Pak and Pla-induced apoptotic protein Bax in PC3 cells, no significant difference between the three, Ric and Pla significantly decreased the expression of anti-apoptotic protein Bcl-2, especially Pla role is very significant concentration 5μMol / L there is a significant downward effect. Pak downward effect is not obvious. Similarly, higher concentrations of Ric, and Pla the caspase-3 is activated, while reducing the expression of PARP large fragment (116KDa), to promote its degradation as a 85 kDa protein fragment. Similarly, caspase-3 activity assay results and these results are consistent, indicating that caspase pathway is involved in the induction of apoptosis of these compounds. Short, double benzyl class compound can be significantly suppressed tumor cell proliferation activity, and first reported leaf moss prime C, Pakyonol and feather moss prime E prostate cancer PC-3 cells having significantly suppressed proliferation role, while inducing PC-3 cell cycle arrest and apoptosis. Induction of apoptosis may increase the Bax/Bcl-2 the ratio, activated caspase pathway.
|