More expression of BDNF associates with lung squamous cell carcinoma and is critical to the proliferation and invasion of lung cancer cells.

BACKGROUND: Brain-derived neurotrophic factor (BDNF) has been reported to promote tumorigenesis and progression in several human malignancies. The purpose of this study was to explore the function of BDNF in lung squamous cell carcinoma (SCC) and adenocarcinoma (ADC). METHODS: The expression of BDNF was examined in 110 samples of lung SCC and ADC by immunohistochemistry. The protein level of BDNF was examined in 25 lung SCC or ADC samples and paired non-tumors by western blot. BDNF expression was also evaluated in human bronchial epithelial cells (HBE) and 4 lung cancer cell lines using western blot. Three BDNF mRNA variants containing exons IV, VI and IX were evaluated in HBE, two SCC (SK, LK2) and two ADC (A549, LTE) cell lines by RT-PCR. The expression and secretion of BDNF were also determined in cells using western blot and ELISA. Then the shRNA specific for BDNF was transfected into LK2 or A549 cells to further elucidate the BDNF knockdown on cell proliferation, apoptosis and invasion, which were confirmed by MTT, flow cytometry and transwell examinations. RESULTS: 71.8 % (79 out of 110) of lung SCC and ADC samples were detected positive BDNF, and high expression of BDNF was significantly correlated with histological type and T stage. Compared with non-tumorous counterparts, BDNF was apparently overexpressed in SCC and ADC tissues. In cell studies, the extensive expression and secretion of BDNF were demonstrated in lung cancer cells compared with HBE cells. Interestingly, the expressions of BDNF mRNA variant IV and VI were identical in all cells examined. However, more expression of BDNF mRNA variant IX was found in SK and LK2 cells. The apoptotic cells were increased, and the cell proliferation and invasion were both attenuated once the expression of BDNF was inhibited. When retreated by rhBDNF, BDNF knockdown cells showed less apoptotic or more proliferative and invasive. CONCLUSIONS: Our data show that BDNF probably facilitates the tumorigenesis of lung SCC and ADC. The expression of BDNF mRNA variant IX is probably more helpful to the upregulation of BDNF in SCC, and intervening the production of BDNF could be a possible strategy to lung cancer therapy.

[Study on inhibitory effect of triterpenoid saponin from Ardisia japonica TSP02 on proliferation and metastasis of human hepatocellular carcinoma cells and its mechanism].

OBJECTIVE: To study the effect of TSP02, a triterpenoid saponin compound from Ardisia japonica, on proliferation and metastasis of in vitro induced human hepatoma HepG2 cells and its molecular mechanism. METHOD: MTT assay was performed to detect the inhibitory effect of TSP02 of different concentrations on proliferation of human hepatoma HepG2 and normal human hepatic cell HL-7702 cells. The changes in cell cycle and apoptotic of processed HepG2 and HL-7702 cells were detected by using flow cytometry. The effect of TSP02 on expression levels of CDK1, 2, 4, apoptosis-related protein Caspase-8, metastasis-related TGF-beta 1 and E-cadherin was measured by western blot. Wound-healing assay and transwell assay were performed to detect the changes in the metastasis of TSPO2-processed HepG2. RESULT: TSP02 significantly inhibited the proliferation of HepG2 cells, with notable time dependence and concentration dependence, but without remarkable effect on normal human liver HL-7702 cells. Compared with the control group, TSP02 processed for 24 h could eliminate HepG2 cells in S stage, significantly increase the cell apoptotic rate. Furthermore, TSP02 was capable of down-regulating the expression of multiple CDK1, 2, 4, and TGF-beta1, and up-regulating the expression and activity of Caspase-8, without significant effect on cycle and apoptotic rate of normal human liver HL-7702 cells. Additionally, TSP02 caused metastasis and invasiveness HepG2 cells, while down-regulating liver cancer invasiveness-related TGF-beta 1 and E-cadherin. CONCLUSION: TSP02 selectively promotes apoptosis of liver cancer cell HepG2, and inhibits its metastasis and invasiveness. TSP02's in vitro antineoplastic activity is related to the changes in cycle and apoptosis proteins, and the regulation in the expression of invasiveness-related TGF-beta 1 and E-cadherin.

13,28-Epoxy triterpenoid saponins from Ardisia japonica selectively inhibit proliferation of liver cancer cells without affecting normal liver cells.

Twenty 13,28-epoxy and related triterpenoid saponins from Ardisia japonica were evaluated for their anti-proliferative activity on human liver cancer cells and normal liver cells. Eight saponins selectively inhibited the growth of liver cancer Bel-7402 and HepG-2 cells without affecting the survival of normal liver HL-7702 cells. The structure-activity relationship analyses indicated that the 13,28-epoxy, 16α-hydroxy, and C-30 methyl moieties in the sapogenin parts and the glycosyl moiety consisting from tetra- to hepta-saccharide units are important for this activity. Among the active saponins, ardisianoside B (2) and 3ß-O-ß-d-glucopyranosyl-(1→2)-[α-l-rhamnopyranosyl-(1→2)-ß-d-glucopyranosyl-(1→4)]-α-l-arabinopyranosyl-13ß,28-epoxy-16α-hydroxyoleanane (3) showed the most potent anti-proliferative activity against Bel-7402 cells in a dose- and time-dependent manner. The selective anti-proliferative activity is attributed to the different cellular responses (CDKs and cyclins levels, cell cycle arrest and apoptosis) between tumor and normal liver cells. Exposure to 2 and 3 selectively led to cell cycle arrest and apoptosis in Bel-7402 cells together with the increased pro-apoptotic caspase-8 and the decreased anti-apoptotic Cdc25A levels.

[The expression of sonic hedgehog in rat vein grafts].

OBJECTIVE: To study the expression of cell cycle related factor sonic hedgehog (SHH) in autogenous vein graft and its relation with neointima formation. METHODS: Autogenous vein graft model were established in 24 male Wistar rats of 8 weeks old and 140 g weight, by transplanting the left jugular vein to intra renal abdominal aorta with microsurgical technique. Graft veins were harvested at 14 d and 28 d after transplantation. The immunohistochemistry and Western blot were used to detect the SHH and PCNA expression in the vein graft. At the same time SHH mRNA was measured by quantitative real-time PCR. The opposite normal veins served as control. RESULTS: Histological staining showed that the percent of SHH+ cells was only (2.0 +/- 0.5)% in the normal vein, but was much more in the vein graft after surgery, as (39.4 +/- 0.4)% and (63.0 +/- 0.3)% respectively (P < 0.01). The expression of SHH and PCNA were both elevated in the vein graft. There was a positive correlation between them which indicated by Western blot (r = 0.808, P < 0.01). The SHH mRNA content also increased in vein graft to 9.5 and 23.8 folds of that in control. CONCLUSION: SHH is upregulated in autogenous vein grafts and may correlated with the proliferation of vascular smooth muscle cells.