cyclin-d1 and tetramethylpyrazine

To investigate the effects of tetramethypyrazine (TMP) on proliferation and apoptosis of the human gastric carcinoma cell line 7901 and its possible mechanism of action.. The viability of TMP-treated 7901 cells was measured with a 3-(4, 5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT) and cell apoptosis was analyzed by flow cytometry. The distribution of cells in different phases of cell cycle after exposure of TMPs was analyzed with flow cytometry. To investigate the molecular mechanisms of TMP-mediated apoptosis, the expression of NF-xBp65, cyclinD1 and p16 in SGC-7901 cells was analyzed by reverse transcription- polymerase chain reaction (RT-PCR) and western blotting.. TMP inhibited the proliferation of human gastric carcinoma cell line 7901 in dose and time dependent manners. Cell growth was suppressed by TMP at different concentrations (0.25, 0.5, 1.0, 2.0 mg/ml), the inhibition rate is 0.46%, 4.36%, 14.8%, 76.1% (48h) and 15.5%, 18.5%, 41.2%, 89.8% (72h) respectively. When the concentration of TMPs was 2.0mg/ml, G1-phase arrest in the SGC-7901 cells was significant based on the data for cell cycle distribution. RT-PCR demonstrated that NF-xBp65 and cyclin D1 mRNA expression was significantly down-regulated in 7901 cells treated with 2.0 mg/ml TMP for 72h (p<0.05), while the p16 mRNA level was up-regulated (p<0.05). The protein expression of NF-xBp65 and cyclin D1 decreased gradually with the increase in TMP concentration, compared with control cells (p<0.05), while expression of protein p16 was up-regulated (p<0.01).. TMP exhibits significant anti-proliferative and pro-apoptotic effects on the human gastric carcinoma cell line SGC-7901. NF-xBp65, cyclinD1 and p16 may also play important roles in the regulation mechanisms.

Topics: Apoptosis; Blotting, Western; Carcinoma; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Down-Regulation; Drug Screening Assays, Antitumor; Gene Expression Regulation, Neoplastic; Humans; Neoplasm Proteins; NF-kappa B; Pyrazines; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Stomach Neoplasms; Up-Regulation

Tetramethylpyrazine (TMP) is an effective component of the traditional Chinese medicine Chuanxiong, which has been reported to have beneficial effects in various types of cancer. However, the activity and mechanism of action of TMP in osteosarcoma (OS) have not been elucidated to date. The aim of the present study was to investigate the inhibitory effect of TMP on OS and its underlying mechanism of action. OS cells were treated with various concentrations of TMP for 48 h. BALB/c nude mice with OS were treated with an intraperitoneal injection of TMP at a dose of 100 mg/kg every other day for 28 days. Cell proliferation was evaluated using an MTT assay. Cell cycle and apoptosis were measured using flow cytometry. The protein expression of nuclear and cytosolic nuclear factor‑κB (NF-κB) p65, BCL‑2 and cyclin D1 was measured using western blot analysis. TMP inhibited the proliferation of OS cells (MG-63, SAOS-2 and U2OS) in a dose‑dependent manner. Additionally, TMP significantly induced apoptosis and G0/G1 arrest in MG-63 OS cells (P<0.05). TMP upregulated the protein expression of cytosolic NF-κB p65, while downregulating the protein expression of nuclear NF-κB p65, BCL-2 and cyclin D1. Furthermore, TMP exerted a significant antitumor effect against OS in a xenograft tumor mouse model and exhibited a low toxicity. The present study provided fundamental evidence for the application of TMP in chemotherapy against OS.

Topics: Active Transport, Cell Nucleus; Animals; Antineoplastic Agents; Bone Neoplasms; Cell Line, Tumor; Cell Nucleus; Cell Proliferation; Cyclin D1; Down-Regulation; Female; G1 Phase Cell Cycle Checkpoints; Gene Expression; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Osteosarcoma; Proto-Oncogene Proteins c-bcl-2; Pyrazines; Transcription Factor RelA; Tumor Burden; Xenograft Model Antitumor Assays