Construction of a DNA vaccine encoding Flk-1 extracellular domain and C3d fusion gene and investigation of its suppressing effect on tumor growth.

Although the critical role of complement component C3d as a molecular adjuvant in preventing virus infection is well established, its role in cancer prophylaxis and treatment is unclear. In this study, we constructed a recombinant plasmid encoding Flk-1 and C3d3 fusion proteins and investigated its transient expression in vitro in transfected eukaryotic cells and its antibody response in immunized mice. Subsequently, we investigated the vaccine's ability to elicit an immune response leading to suppression of angiogenesis and tumor growth in mice bearing bladder transitional cell carcinoma. Using Western blotting, immunocytochemistry, and flow cytometry, we detected the expression of Flk-1 and C3d3 fusion proteins in COS-7 cells transfected with these recombinant plasmids. Further binding experiment using CR2 (C3d receptor) positive Raji cells that were incubated with transfected COS-7 supernatant indicated that C3d was successfully fused to Flk-1. Although both vaccines elicited peak antibody levels at 5 weeks, Flk-1-specific antibody titer in pSG.SS.Flk-1(ECD).C3d3.YL-immunized mice was significantly higher when compared to pSG.SS.Flk-1(ECD).YL-immunized mice. The results of experiments with bladder tumor-bearing mice showed that the vaccine inhibited tumor growth significantly. These results suggest that C3d plays a critical role in tumor immunotherapy by promoting antibody response in Flk-1-based DNA vaccines. This approach may provide a new strategy for the rational design of anti-angiogenic therapies for the treatment of solid tumors and provide a basis for the further exploitation and application of the anti-angiogenesis DNA vaccines.

Proliferative response of human prostate cancer cell to hormone inhibited by androgen receptor antisense RNA.

BACKGROUND: The failure of endocrine treatment for advanced prostate cancer might be related to aberrant activation of androgen receptor (AR). Prostate cancer cell line LNCaP contains AR that can be activated by androgen, estrogen and progesterone. This study was set to investigate the effects of antisense AR RNA on growth of LNCaP cultured in medium containing varied concentrations of R1881, 17beta-estradiol, and progesterone, respectively. METHODS: LNCaP cells transfected with antisense AR RNA retroviral vector pL-AR-SN were designated as LNCaPas-AR. LNCaP cells containing empty vector pLXSN served as LNCaPNeo. LNCaP and LNCaPNeo were taken as controls. In vitro cell growth assay, proliferative cells of LNCaP and tranfected LNCaPs were counted by typan staining when they cultured with synthetic androgen R1881, 17beta-estradiol, and progesterone, respectively. RESULTS: Growth of LNCaPas-AR was inhibited significantly (P < 0.05) compared with that of LNCaP and LNCaPNeo at 1 nmol/L R1881, 10 nmol/L 17beta-estradiol, and 1 nmol/L progesterone, respectively. No difference was seen between LNCaP and LNCaPNeo (P > 0.05). Microscopic observation showed that LNCaP and LNCaPNeo cells grew well, but only few LNCaPas-AR cells were alive. CONCLUSIONS: Our observations indicate that antisense AR RNA retroviral vector pL-AR-SN could change androgen-independent characteristics of LNCaP cells, which might shed some novel insights into the treatment of androgen-independent prostate cancer.

Preparation of protamine cationic nanobubbles and experimental study of their physical properties and in vivo contrast enhancement.

In this study, we aimed to prepare a novel type of microbubble (MB), protamine cationic nanobubble (NB), to provide a new vector for tumor gene therapy. We prepared cationic NBs with protamine and other lipid components using mechanical oscillation. The protamine cationic NBs had a mean diameter of 521.2 ± 37.57 nm, a zeta potential of +18.5 mV, and a gene-carrying capacity of 15.69 µg androgen receptor (AR) siRNA per 10(8) NBs. The cationic NBs exhibited superior contrast enhancement for in vivo imaging compared with SonoVue (Bracco, Geneva, Switzerland), and their physical properties did not change significantly after 1 wk; meanwhile, the transfection efficiency of the cationic NBs in androgen-independent prostate cancer cells mediated by ultrasound irradiation was better than that of liposomes (82.17 ± 7.4% vs. 55.04 ± 5.4%, p < 0.01). Therefore, the protamine cationic NB can be considered for use as a novel type of gene-loading MB for ultrasound imaging and MB-mediated gene therapy of tumors.

Imaging diagnosis, transurethral endoscopic observation, and management of 43 cases of persistent and refractory hematospermia.

The goal of this study was to explore minimally invasive transurethral imaging and surgery for the treatment of severe, persistent hematospermia in cases that were refractory to conservative treatments. The study included 43 patients (aged 22-77 years; average, 44.6 years) with long-lasting, severe hematospermia, accompanied by discomfort or pain in the lumbosacral or perineal region, dysuria, frequent micturition, decreased semen volume, and/or azoospermia. Patient symptoms had persisted for 1 to 10 years (average, 5.3 years). Computed tomography or magnetic resonance imaging of each patient was evaluated, and transurethral surgery was performed. The causes of hematospermia were identified in all 43 patients, and their ejaculatory duct obstruction or seminal vesiculitis was successfully treated. No serious intraoperative or postoperative complications occurred. Pathologic analyses revealed that all of the resected or biopsied seminal vesicle tissues had chronic nonspecific inflammation in the seminal vesicle wall, and no tumors were identified. Preoperative symptomology of hematospermia disappeared in all patients followed up for 2 to 30 months (average, 16 months). A single patient experienced recurrence at 11 months and had a second minimally invasive surgery that was curative. A total of 95.3% (41 of 43) of the patients experienced normal orgasmic intensity after surgery. Magnetic resonance imaging is a valuable and accurate diagnostic method for the identification of causative factors underlying hematospermia. Transurethral dilation of ejaculatory ducts, incision of the verumontanum or the distal end of the ejaculatory ducts, and incision or resection of the relevant cysts represent simple, safe, and reliable approaches for the management of refractory cases of hematospermia that do not respond to conservative treatments.