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.

Up-regulation of glucosylceramide synthase in urinary bladder neoplasms.

OBJECTIVE: To investigate the relationships between the clinicopathologic features and the expression of GCS in bladder cancer. METHODS AND MATERIALS: Using immunohistochemistry and Western blotting method, 75 bladder cancer specimens were tested for expression of GCS. The correlation of GCS with clinicopathologic features of the patients was analyzed in combination with clinical data. Statistics analyses were done with SPSS 13.0 software, χ(2) test, Fisher's exact test, Kaplan-Meier method, Log-rank test. RESULTS: High and low level expression of GCS explored by immunohistochemistry were 61.3 (46/75) and 39.6 (29/75), respectively. The high expression group (n = 46) showed a significant correlation with high histologic grade (P = 0.021) and tended to show (P = 0.045) that up-expression of GCS was positive related to BNs with lymph node metastasis among the various clinicopathologic characteristics. The overall 5-year survival and disease-free survival rates were 39.5% and 18.4%, respectively. Mean overall survival time was 60.3 months for the low expression group and 45.1 months for the high expression group. Mean disease-free survival was 36.2 months for the low-expression group and 27.3 months for the high-expression group. CONCLUSION: Our study suggested that up-regulation of GCS might make an aggressive choice of surgical therapy. A high expression of GCS seemed to be an indicator of poor prognosis.

[Expression of SOCS3 and Pyk2 and their correlation in non-small cell lung cancer].

OBJECTIVE: To investigate the expression of SOCS3 and Pyk2 and their correlations in non-small cell lung cancer (NSCLC). METHODS: The expression of SOCS3 and Pyk2 was detected in 100 cases of NSCLC, human bronchial epithelial cells (HBE) and 6 lung cancer cell lines by immunohistochemistry and immunofluorescence staining. The methylation status of SOCS3 was investigated in A549 cells by methylation-specific PCR. A549 cells were either treated with a demethylation agent 5-aza-2'-deoxycytidine (5-aza) or transfected with three SOCS3 mutants with various functional domains deleted. Besides, the cells were pretreated with a proteasome inhibitor ß-lactacystin where indicated. The effects of SOCS3 on Pyk2 expression, Pyk2 Tyr 402 and ERK1/2 phosphorylations were assessed by Western blot. RT-PCR was used to estimate Pyk2 mRNA levels. Transwell experiments were performed to evaluate cell migration. RESULTS: SOCS3 (43.0%, 43/100) and Pyk2 (65.0%, 65/100) were expressed in NSCLC. A significant negative correlation was found between SOCS3 and Pyk2 in both NSCLC tissues and cell lines. SOCS3 was aberrantly methylated and 5-aza restored SOCS3 expression. Transfection studies indicated that exogenous SOCS3 interacted with Pyk2, and both Src homology 2 (SH2) and kinase inhibitory region (KIR) domains contributed to Pyk2 binding. Furthermore, SOCS3 was found to inhibit Pyk2-associated ERK1/2 activity in A549 cells. SOCS3 possibly promoted degradation of Pyk2 in a SOCS-box-dependent manner and interfered with cell migration. CONCLUSIONS: The data indicates that SOCS3 definitely plays roles in regulating Pyk2 signaling, and cell motility. Decreased SOCS3 induced by methylation may confer a migration advantage to A549 cells.

Glypican3 in genetically modified human monocyte-derived dendritic cells induced specific cytotoxity against glypican3 overexpressing human hepatocellular carcinoma cells in vitro.

OBJECTIVE: To transduce the new hepatocellular carcinoma (HCC) specific antigen gene glypican3 (GPC3) into dendritic cells (DCs) and to observe the in vitro cytotoxic effect induced by the genetically modified DCs against the hepatocellular carcinoma cell line (HepG2). METHODS: This study was performed in China Medical University Shenyang, China from September 2007-February 2008. The design of the study was to modify DCs with GPC3 and to be used to activate human T cells and elicit a cell-mediated immune response against HepG2 in vitro. The GPC3 gene expression was identified by western blot and immunocytochemistry. The proliferation of responder cells and cytotoxicity against HepG2 were examined by water-soluble tetrazolium salt -1 and lactate dehydrogenase assay respectively. The interferon-y (IFN-y) secreted was detected by ELISA assay. RESULTS: Both Western blot and immunocytochemical analysis assured the validity of GPC3 transfection. Glypican3 modified DCs were potent in inducing responder cells proliferation and IFN-y production. The cytotoxicity in the group of GPC3 transfected DCs were (38.90+/-0.95%) at the ratio of effector cells/target cells E/T:100:1, 30.83+/-1.24% at the ratio of E/T:50:1, and 23.84+/-0.65% at the ratio of E/T:10:1, respectively (which is significant compared with other groups, p<0.001). And the GPC3 modified DCs showed ability to induce high specific cytotoxicity against HepG2 in vitro. CONCLUSION: The effector cells stimulated with DCs that were transfected with pEF-hGPC3 plasmid could effectively lyse GPC3 expressing HepG2 cells, which suggested that those genetically engineered DCs have the potential to serve as novel vaccine for HCC.