Anti-tumor activity and the mechanism of a green tea (Camellia sinensis) polysaccharide on prostate cancer.

In this study, a homogeneous polysaccharide (GTP), with a molecular weight of 7.0 × 104 Da, was isolated from Green tea, which was only composed of glucose. The antitumor effects of GTP on prostate cancer (PC) cell line along with the possible mechanism was examined. First, we investigate the potential role of microRNA-93 (miR-93) in PC progression. Our results showed that miR-93 was significantly upregulated in human PC tissues and several PC cell lines, and its overexpression was correlated with poor survival in PC patients. Furthermore, functional analysis showed that miR-93 overexpression promoted the migration, invasion and proliferation of PC-3 cells transfected with miR-93 mimics, while its knockdown displayed an opposite result in DU145 cells following miR-93 inhibitor transfection. Additionally, in vivo tumorigenic studies on nude mice confirmed that miR-93 mimic treatment accelerated the growth of PC-3 xenograft tumors. As expected, GTP (25, 50 and 100 µg/ml) inhibited growth of PC-3 cells via inducing apoptosis, which was achieved by elevation of bax/bcl-2 ratio and caspae-3 protein expression, as well as a decrease of miR-93. Thus, miR-93 may be a potential therapeutic target by GTP for PC therapy.

MiR-93 functions as a tumor promoter in prostate cancer by targeting disabled homolog 2 (DAB2) and an antitumor polysaccharide from green tea (Camellia sinensis) on their expression.

Our previous work has demonstrated that the role of miR-93 in prostate cancer (PC) progression. The aim of this study was to determine the downstream gene regulated by miR-93 and the molecular mechanisms underlying its roles in PC. Bioinformatics analysis and luciferase reporter assays predicted disabled homolog 2 (DAB2) as a direct target gene of miR-93. Real time quantitative polymerase chain reaction (qRT-PCR) and Western blot analysis revealed that DAB2 was tumor repressor in PC cells, and its mRNA expression was negatively correlated with miR-93 in PC tissues. Gain and loss of function experiments also indicated DAB2 overexpression significantly suppressed PC cells proliferation, invasion and migration, while knockdown of its expression came to the opposite effect. Furthermore, a rescue experiment indicated miR-93 directly regulated PC cell growth and migration, as well as AKT and ERK activation by targeting DAB2. Additionally, antitumor effect of a Green tea polysaccharide (GTP) on PC-3 cells could be achieved by increasing DAB2 protein expression and inactivating AKT and ERK1/2 signaling. Our study suggests that miR-93 promoted PC progression and metastasis by repressing DAB2 to activate Akt/ERK1/2 pathway, and elevation of DAB2 and inactivation of Akt/ERK1/2 might be a potential therapeutic target for PC by GTP.

Histone Deacetylase (HDAC) Inhibitor, Suberoylanilide Hydroxamic Acid (SAHA), Induces Apoptosis in Prostate Cancer Cell Lines via the Akt/FOXO3a Signaling Pathway.

BACKGROUND Histone deacetylase (HDAC) inhibitors are emerging as a new class of anti-cancer drugs that promote cancer cell apoptosis, and include suberoylanilide hydroxamic acid (SAHA). The aim of this study was to investigate the mechanism of SAHA-induced apoptosis in human prostate cancer cell lines, DU145 and PC-3. MATERIAL AND METHODS Cell lines, DU145 and PC-3, were studied before and after treatment with SAHA. The effects of SAHA treatment on cell proliferation were studied using the MTT cell proliferation assay. Annexin-V-fluorescein isothiocyanate (FITC) and propidium iodide (PI) staining were used to study the effects of SAHA treatment on cell apoptosis. Western blotting, quantitative polymerase chain reaction (qPCR) and short interfering (si)RNA assays were performed to study the effects of SAHA treatment on apoptotic and cell cycle proteins and the Akt/FOXO3a signaling pathway. RESULTS Treatment with SAHA inhibited cell proliferation in human prostate cancer cell lines DU145 and PC-3 cells in a dose-dependent way. Cell cycle analysis and Annexin-V FITC/PI staining showed that treatment with SAHA resulted in G2/M cell cycle arrest and increased cell apoptosis in a dose-dependent way. Also, treatment with SAHA reduced the protein expression levels cyclin B and cyclin A2 and promoted the activation of FOXO3a by inhibiting Akt activation. Western blotting, the siRNA assay, and qPCR showed that FOXO3a, the Bcl-2 family of proteins, survivin, and FasL were involved in SAHA-induced apoptosis in prostate cancer cells grown in vitro. CONCLUSIONS Treatment with SAHA promoted apoptosis via the Akt/FOXO3a signaling pathway in prostate cancer cells in vitro.

[The highly expressed secreted phosphoprotein 1 gene in prostate cancer metastasis: a microarray-based bioinformatic analysis].

OBJECTIVE: To investigate the composition, function, and regulatory mechanisms of the secreted phosphoprotein 1 (SPP1) gene in metastatic prostate cancer. METHODS: We obtained the data about the whole genomic expression profiles on prostate cancer metastasis from the GEO database, and performed data-mining and bioinformatic analysis using BRB-Array Tools and such softwares as Protparam, MotifScan, SignalP 4.0, TMHMM, NetPhos2.0, PredictProtein, GO, KEGG, and STRING. RESULTS: Totally, 73 co-expressed differential genes in prostate cancer metastasis were identified, 21 up-regulated and 52 down-regulated (P <0.01). Bioinformatic analysis indicated that the highly expressed SPP1 gene encoded 314 amino acids and contained 2 N-glycosylation sites, 8 casein kinase II phosphorylation sites and 3 protein kinase C phosphorylation sites, playing essential roles in extracellular matrix (ECM) binding, ossification, osteoblast differentiation, cell adhesion, PI3K-Akt signaling pathway, focal adhesion, Toll-like receptor signaling pathway, and ECM-receptor interaction. CONCLUSION: The bioinformatic method showed a high efficiency in analyzing microarray data and revealing internal biological information. SPP1 may play an important role in prostate cancer metastasis and become a novel biomarker for the diagnosis of prostate cancer metastasis and a new target for its treatment.

[Single- and two-layer gradient centrifugation in sperm separation: comparison and appraisal].

OBJECTIVE: To appraise the effect of single- and two-layer Percoll density gradient centrifugation in sperm separation. METHODS: Twenty semen specimens underwent single-(50%) and two-layer (90% and 45%) density gradient centrifugation, respectively. The sperm class analyzer (SCA) was used to analyze sperm density, motility and dynamic parameters and round cell density before and after the treatment. RESULTS: After separation, the sperm recovery rate of the single-layer method was (65.5 +/- 12.8)%, significantly higher than that of the two-layer method (P < 0.01). The percentages of grade a sperm of the single- and two-layer method were significantly higher than pre-treatment (P < 0.05, P < 0.01), that of the single-layer was significantly lower than that of the two-layer method (P < 0.05), but the percentage of grade c sperm of the former was significantly higher than that of the latter (P < 0.05). Compared with pre-treatment, the percentage of grade a + b sperm of the two-layer method was significantly higher (P < 0.05), while that of the single-layer method showed no significant difference (P > 0.05), and the round cell density of both the methods was significantly lower (P < 0.05, P < 0.01), with no significant differences between the two methods (P > 0.05). CONCLUSION: The single-layer method yields a higher rate of sperm recovery and causes little change in the sperm motility, while the two-layer method effects a lower rate and significantly improves sperm motility. Both the methods can efficiently separate sperm from round cells, and each has its own advantages and its application value in in vitro treatment of sperm.

[Minute dose of tadalafil for nocturnal penile tumescence].

OBJECTIVE: To investigate the efficacy of tadalafil on nocturnal penile tumescence (NPT). METHODS: Thirty-four patients with organic erectile dysfunction (ED) were treated with oral tadalafil at the dose of 10 mg/3 d before bedtime. A month later, 14 of the patients were observed for NPT by nocturnal electrobioimpedance volumetric assessment (NEVA). RESULTS: The parameters of erectile function significantly improved in the 14 patients (P < 0.05). CONCLUSION: Oral administration of minute dose of tadalafil can improve NPT in organic ED patients.

[Identification of human testicular embryonal carcinoma proteins by two-dimensional gel electrophoresis and mass spectrometry].

OBJECTIVE: To separate and identify human testicular embryonal carcinoma proteomics using two-dimensional electrophoresis (2-DE) and mass spectrometry. METHODS: Immobilized pH gradient two-dimensional polyacrylamide gel electrophoresis was used to separate the total proteins of the samples. After silver staining, PDQuest 7.30 image analysis software was applied to analyze the 2-DE images. Three of the proteins highly expressed in human testicular embryonal carcinoma were identified by matrix-assisted laser adsorption/ionization-time of flight-tandem mass spectrometry (MALDI-TOF-MS/MS). RESULTS: 2-DE effectively screened the differentially expressed proteins in the carcinoma tissues. Three proteins highly expressed in the carcinoma were successfully identified. CONCLUSION: The proteins of human testicular embryonal carcinoma can be effectively separated and analyzed using 2-DE and mass spectrometry. Proteomic analysis offers a new means for further study of this carcinoma.

[Mining the specifically expressed genes in sperms based on the bioinformatics methods].

OBJECTIVE: To analyze the specifically expressed genes in sperms for better understanding of the molecular characteristics of sperms. METHODS: The hybridization data the genes in the sperms, oocytes and 10 normal tissues were retrieved from the GEO database to identify the genes expressed specifically in sperms and the patterns of their regulation using such bioinformatic tools as GATHER, PANTHER and DAVID. RESULTS AND CONCLUSIONS: Comparison of the spermatozoal gene expression profiles with those of the normal tissues identified 8998 differentially expressed probes, among which 25 genes were up-regulated by over 200 folds in the sperms. Comparison of the gene expression profiles between the oocytes and normal tissues resulted in the identification of 8981 differentially expressed probes. Of the 1709 up-regulated genes in the sperm with a ratio>5, 1218 genes showed similar expressions in the oocytes and the normal tissues, and 129 were up-regulated and 362 down-regulated in the oocytes. The 362 genes up-regulated in the sperms but down-regulated in the oocytes were involved mainly in protein modification and metabolism and nucleic acid metabolism, but very few participated in the intracellular signaling pathways. Numerous transcriptional factors containing the KRAB domain and receptor- independent serine/threonine kinase were specifically overexpressed in sperms, and the a very high proportion of the genes specifically overexpressed in the sperms coincided with the overexpressed genes in the neural stem cells and embryonic stem cells. The genes involved in the glycolysis were down-regulated in the sperms. These findings in the genes specifically expressed in the sperms by data mining using bioinformatic methods may provide better insight into the molecular characteristics of the sperms.

[Literature-mining and bioinformatic analysis of androgen-independent prostate cancer-specific genes].

OBJECTIVE: To compare the differences of the gene expressions in androgen-independent and androgen-dependent prostate cancer (ADPC), gain a deeper insight into the molecular mechanism of androgen-independent prostate cancer (AIPC), and find effective means for its clinical diagnosis and treatment. METHODS: Eats of genes highly-associated with prostate cancer were obtained by mining PubMed with the FACTA tool, and the specifically expressed genes in AIPC were analyzed with a set of bioinformatic tools including GATHER, PANTHER, STRING and ToppGene. RESULTS: A total of 128 genes specifically expressed in AIPC were identified, as compared with 23 that were specific to ADPC. Bioinformatic analysis showed the essential roles of AIPC-specific genes in such important biological processes as cell signal transduction, cell adhesion, apoptosis, oncogenesis, cell proliferation and cell differentiation. CONCLUSION: Such genes as MMPJ, EGFR, MMP2, ADM, MIF, IGFBP3, 112, MET, BAD, RHOA, SPP1, EP300, SMAD3, RAE1, PTK2, and TGFB2 may play important roles in transforming ADPC into AIPC.