AG36 Inhibits Human Breast Cancer Cells Proliferation by Promotion of Apoptosis In vitro and In vivo

Abstract

AG36 is the biotransformation product of triterpenoid saponin from Ardisia gigantifolia stapf. In this study, the antitumor activity and underlying molecular mechanisms of AG36 against human breast MCF-7, MDA-MB-231, and SK-BR-3 cancer cells were investigated. AG36 inhibited the viability of MCF-7, MDA-MB-231, and SK-BR-3 cells in a dose and time-dependent manner, with an IC50 of approximately 0.73, 18.1, and 23.4 μM at 48 h, respectively. AG36 obviously induced apoptosis and G2/M arrest of all the three breast cancer cells. Moreover, AG36 decreased the protein expression of cycle regulatory proteins cyclin B1 or cyclin D1. In MCF-7 and MDA-MB-231 cells, AG36 strongly increased the cleaved caspase-3 and -8 protein expressions, while in SK-BR-3 cells, AG36 only increased the protein expression of cleaved caspase-3. In all the three breast cancer cells, the ratio of Bax/Bcl-2 and cytosolic cytochrome c content increased significantly compared with control group. The death receptor-related proteins Fas/FasL, TNFR1, and DR5 were detected by Western blot, it showed that different breast cancer cells activated the death receptor-mediated extrinsic caspase-8 pathway through different receptors. In addition, the caspase-8 inhibitor z-IETD-fmk could significantly block AG36-triggered MCF-7 cells apoptosis. The in vivo studies showed that AG36 significantly inhibited the growth of MCF-7 xenograft tumors in BALB/c nude mice comparing with control. In conclusion, AG36 inhibited MCF-7, MDA-MB-231, and SK-BR-3 cells proliferation by the intrinsic mitochondrial and the extrinsic death receptor pathways and AG36 might be a potential breast cancer therapeutic agent.

Cell-Based Reporter Release Assay to Determine the Potency of Proteolytic Bacterial Neurotoxins

“…Surprisingly, the expression of the substrate of BoNT-B was very low on the mRNA level and not detectable by the immunoblot on the protein level ( Figure 4 ). The low expression level of VAMP-2 in SIMA cells and other neuroblastoma cell lines, such as SHSY-5Y, was shown independently by others [ 21 ]. In contrast to the determination of neo-epitope-dependent activity, which requires high concentrations of the substrate proteins in the test cell line, necessitating transgenic expression of the protein to improve sensitivity of the assay [ 21 ], the low expression of the substrate SNARE protein in the current functional assay would correspond to high sensitivity since the functional reserve of SNARE protein left after partial cleavage by the enzyme would be low.…”

“…The low expression level of VAMP-2 in SIMA cells and other neuroblastoma cell lines, such as SHSY-5Y, was shown independently by others [ 21 ]. In contrast to the determination of neo-epitope-dependent activity, which requires high concentrations of the substrate proteins in the test cell line, necessitating transgenic expression of the protein to improve sensitivity of the assay [ 21 ], the low expression of the substrate SNARE protein in the current functional assay would correspond to high sensitivity since the functional reserve of SNARE protein left after partial cleavage by the enzyme would be low. Although VAMP-2 was not detectable by Western Blot, its presence in SIMA cells, albeit at very low concentrations, was confirmed by the inhibition of stimulus-dependent luciferase release by the incubation of the cells with tetanus toxin ( Figure 3 ).…”

The ethnomedicinal and functional uses, phytochemical and pharmacology of compounds from Ardisia species: An updated review

“…Compounds 125 (in NCI‐H460 cells 78 ), 127 (in MCF‐7 and MDA‐MB‐231 cells 80 ), 10 (U251MG cells 31 ) and 68 (in PANC‐1 50 and A549 cells 72 ) increased the expression of the proapoptotic protein, caspase‐3 104 . Compound 10 increased the expression of caspase‐8, a proapoptotic protein, 105 in U251MG cells 31 and compound 68 increased the expression of caspase‐9, a proapoptotic protein, in PANC‐1 cells 50 .…”

Hoạt Tính Ức Chế Sự Tăng Sinh Tế Bào Của Dịch Chiết Từ Lá Cây Cơm Nguội Lông (Ardisia Villosa) Trên Tế Bào Ung Thư Dạ Dày Mkn45

“…Các nghiên cứu trước đây đã chỉ ra rằng, dịch chiết từ một số loài thuộc chi Ardisia có khả năng cảm ứng apoptosis đối với các dòng tế bào ung thư vú thông qua sự tăng cường biểu hiện của các protein caspase 8 và caspase 3 [11]. Bên cạnh đó, các protein thụ thể của tế bào chết gồm Fas/FasL, TNFR1 và DR5 cũng được biểu lộ tăng sau khi tế bào xử lý với dịch chiết chứa saponin từ cây Ardisia gigantifolia Stapf [16]. Trong nghiên cứu này, bước đầu chúng tôi đã chỉ ra sự biến đổi kiểu nhân của một tế bào bình thường thành kiểu nhân đặc trưng của apoptosis sau khi xử lý với dịch chiết ethanol chứa saponin từ loài Ardisia villosa.…”