Triptolide inhibits viability and induces apoptosis in liver cancer cells through activation of the tumor suppressor gene p53.

The present study investigated the effect of triptolide on viability and apoptosis along with underlying mechanism in liver cancer cells. CCK-8 assay showed that triptolide treatment for 48 h significantly reduced the viability of HepG2 and QSG7701 cells at 50 µM concentration. Annexin V-FITC and propidium iodide staining showed that triptolide treatment of HepG2 cells at 50 µM concentrations induced apoptosis in 56.45% cells compared to only 2.36% cells in the control cultures. Western blot assay showed that treatment of HepG2 cells with 50 µM concentration of triptolide significantly induced phosphorylation of p53 in a 2 h-treatment. Phosphorylation of histone H2A.X indicator of DNA damage was induced by triptolide treatment after 12 h in HepG2 cells. The level of nuclear p53 in a 6 h-treatment with 0, 10, 20, 30, 40 and 50 µM concentration of triptolide was found to be 15.3, 19.6, 28.5, 43.7, 63.8 and 91.5%, respectively. Treatment of HepG2 cells with triptolide at 50 µM concentration caused a significant increase in the binding potential of p53 to DNA. Triptolide treatment of HepG2 cells caused a significant increase in the expression of p21, Bax and DR5 genes in HepG2 cells. It also increased the expression of miR-34b and miR-34c in HepG2 cells markedly. Treatment of HepG2 cells with p53 inhibitor, pifithrin-α prior to incubation with triptolide significantly prevented induction of cell apoptosis. Suppression of p53 expression by siRNA inhibited the expression of p53 as well as its target genes along with the prevention of apoptosis induction. In conclusion, triptolide inhibits viability and induces apoptosis in liver cancer cells through activation of the tumor suppressor gene p53. Thus, triptolide can be used for the treatment of liver cancer.

Multivariate prognostic study on node-positive gastric cancer: is tumor size a prognostic indicator?

BACKGROUND/AIMS: We analyzed the clinicopathological factors of patients with node-positive gastric cancer, evaluated the prognostic factors associated with long-term survival and clarified the effect of tumor size on long-term survival. METHODOLOGY: The study included 591 patients who underwent curative resection for node-positive gastric cancer. Clinicopathological prognostic variables were evaluated as predictors of long-term survival by univariate and multivariate analyses. RESULTS: The 5-year survival rate was influenced by tumor size, tumor location, depth on invasion, level of lymph node metastasis, Borrmann classification, histological type, liver metastasis, peritoneal dissemination and disease stage. Of these, independent prognostic factors were depth on invasion and lymph node metastasis. Tumor size is an influence but not independent factor for the prediction of long-term survival in patients with node-positive gastric cancer. CONCLUSIONS: In patients with node-positive gastric cancer, two independent prognostic factors were depth on invasion and the status of lymph node metastasis.

[Exploration on the increased sensitivity to docetaxel and reversing mechanism of drug resistance of antisense survivin RNA in gastric cancer cell line SGC7901 cells].

OBJECTIVE: To explore the effects of survivin antisense RNA on apoptosis and chemosensitivity to docetaxel in gastric cancer line SGC7901 cells, and its relation to mdr-1. METHODS: survivin antisense eukaryotic vector anti-pcDNA3-svv was transfected into SGC7901 cells by electorporation and positive clone was screened out. survivin protein and mdr-1 mRNA were determined by Western blot and RT-PCR. Apoptosis-inducing effect was examined by electron microscopy. Sensitivity to docetaxel was examined by MTT. Expression of mdr-1 and survivin mRNA were detected in the SGC7901 cells after drug-resisitance induction. RESULTS: The expression of survivin protein of SGC7901 cells after transfection reduced significantly than that of non-transfected cells. MDR indexes of transfection group and non-transfection group were 0.196 +/- 0.013 and 3.126 +/- 0.019, respectively. The IC50 of transfection group to docetaxel was (16.7 +/- 1.98) microg/L and non-transfection group was (55.7 +/- 1. 89) microg/L, with a statistically significant difference. Expression of survivin mRNA in drug-resistant cells decreased along with the decreasing of mdr-1. CONCLUSION: Antisense surivivin RNA can induce apoptosis in gastric cancer cells and increase sensitivity to docetaxel. The reversing mechanism of drug resistance is related with decreasing of mdr-1.

[Survivin antisense RNA induces apoptosis and sensitizes ovarian cancer cell line SKOV3 to docetaxel].

BACKGROUND & OBJECTIVE: Survivin gene overexpresses in a variety of human tumors, and plays an important role in cell apoptosis and drug resistance of tumors. This study was designed to establish Survivin antisense RNA, and explore its effects on apoptosis of ovarian cancer cell line SKOV3 and sensitivity to docetaxel. METHODS: Survivin antisense eukaryotic expression vector anti-pcDNA3-svv was established, and transfected into SKOV3 cells by electroperforation. Positive clones (SKOV3-SVVanti) were screened out. Survivin mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR); Survivin protein was detected by Western blot. The effect of Survivin antisense RNA on apoptosis of SKOV3 cells was measured by flow cytometry and observed under electron microscope; its effect on sensitivity of SKOV3 cells to docetaxel was examined by MTT assay. RESULTS: The mRNA and protein levels of Survivin were obviously lower in SKOV3-SVVanti cells than in control cells. Terminal apoptosis changes were observed under electron microscope after transfection. The apoptosis rate was 19%. The 50% inhibitory concentration (IC50) of docetaxel was significantly lower for SKOV3-SVVanti cells than for control cells [(13.3+/-2.2) ng/ml vs. (53.2+/-2.4) ng/ml, P<0.05]. CONCLUSION: Surivivin antisense RNA can induce apoptosis of SKOV3 cells, and sensitize SKOV3 cells to docetaxel.