Phosphorylation affects the DNA affinity of the nuclear protein 24/7 from human tumor cells

AbstractIn the present study we investigated the binding behavior of nuclear proteins from human tumor cells to human placental DNA coupled on CNBr-activated Sepharose. When nuclear proteins soluble in 5 M urea prepared from serum-stimulated cells and containing the majority of the nonhistone proteins were applied onto a dsDNA column, next to several other proteins one prominent group consisting of at least 2 distinct proteins with a pI at 7 and a molecular mass near 24 kDa bound to DNA. The DNA-binding ability of one of them is lost on phosphorylation and is recovered after dephosphorylation using alkaline phosphatase. Additionally, normal human fibroblasts taken as controls exhibit comparatively low levels of these 24/7 proteins, indicating a particular function in tumor cells

Molecular Characterization of Cancer Associated Fibroblasts in Prostate Cancer

Background: Stromal components surrounding epithelial cancer cells seem to play a pivotal role during epithelial-to-mesenchymal transition (EMT), tumor invasion, and metastases. To identify the molecular mechanisms underlying tumor–stroma interactions may yield novel therapeutic targets for prostate cancer. Methods: Gene expression profile of prostate-cancer associated fibroblast (PCAF) and prostate non-cancer associated fibroblast (PNAF) cells isolated from radical prostatectomy was performed by Illumina, analyzed, and further processed by Ingenuity®: IPA® software. qRT-PCR was performed on an independent set of 17 PCAF, 12 PNAF, and 12 fibroblast cell lines derived from patients with benign prostatic hyperplasia (BPHF). Results: Using microarray analysis, we found six upregulated genes and two downregulated genes in PCAFs compared to PNAFs. To validate microarray results, we performed qRT-PCR for the most significantly regulated genes involved in the modulation of proliferation and androgen resistance on an independent set of PNAF, PCAF, and BHPF samples. We confirmed the increased expression of SCARB1, MAPK3K1, and TGF-β as well as the decreased expression of S100A10 in PCAFs compared to PNAFs and BPHFs. Conclusions: These results provide strong evidence that the observed changes in the gene expression profile of PCAFs can contribute to functional alteration of adjacent prostate cancer cells

Molecular Characterization of Cancer Associated Fibroblasts in Prostate Cancer

Background: Stromal components surrounding epithelial cancer cells seem to play a pivotal role during epithelial-to-mesenchymal transition (EMT), tumor invasion, and metastases. To identify the molecular mechanisms underlying tumor-stroma interactions may yield novel therapeutic targets for prostate cancer. Methods: Gene expression profile of prostate-cancer associated fibroblast (PCAF) and prostate non-cancer associated fibroblast (PNAF) cells isolated from radical prostatectomy was performed by Illumina, analyzed, and further processed by Ingenuity (R) : IPA (R) software. qRT-PCR was performed on an independent set of 17 PCAF, 12 PNAF, and 12 fibroblast cell lines derived from patients with benign prostatic hyperplasia (BPHF). Results: Using microarray analysis, we found six upregulated genes and two downregulated genes in PCAFs compared to PNAFs. To validate microarray results, we performed qRT-PCR for the most significantly regulated genes involved in the modulation of proliferation and androgen resistance on an independent set of PNAF, PCAF, and BHPF samples. We confirmed the increased expression of SCARB1, MAPK3K1, and TGF-beta as well as the decreased expression of S100A10 in PCAFs compared to PNAFs and BPHFs. Conclusions: These results provide strong evidence that the observed changes in the gene expression profile of PCAFs can contribute to functional alteration of adjacent prostate cancer cells

Antimicrobial peptides of the Cecropin-family show potent antitumor activity against bladder cancer cells

<p>Abstract</p> <p>Background</p> <p>This study evaluated the cytotoxic and antiproliferative efficacy of two well-characterized members of the Cecropin-family of antimicrobial peptides against bladder tumor cells and benign fibroblasts.</p> <p>Methods</p> <p>The antiproliferative and cytotoxic potential of the Cecropins A and B was quantified by colorimetric WST-1-, BrdU- and LDH-assays in four bladder cancer cell lines as well as in murine and human fibroblast cell lines. IC₅₀values were assessed by logarithmic extrapolation, representing the concentration at which cell viability was reduced by 50%. Scanning electron microscopy (SEM) was performed to visualize the morphological changes induced by Cecropin A and B in bladder tumor cells and fibroblasts.</p> <p>Results</p> <p>Cecropin A and B inhibit bladder cancer cell proliferation and viability in a dose-dependent fashion. The average IC₅₀values of Cecropin A and B against all bladder cancer cell lines ranged between 73.29 μg/ml and 220.05 μg/ml. In contrast, benign fibroblasts were significantly less or not at all susceptible to Cecropin A and B. Both Cecropins induced an increase in LDH release from bladder tumor cells whereas benign fibroblasts were not affected. SEM demonstrated lethal membrane disruption in bladder cancer cells as opposed to fibroblasts.</p> <p>Conclusion</p> <p>Cecropin A and B exert selective cytotoxic and antiproliferative efficacy in bladder cancer cells while sparing targets of benign murine or human fibroblast origin. Both peptides may offer novel therapeutic strategies for the treatment of bladder cancer with limited cytotoxic effects on benign cells.</p

Silencing of the SEC62 gene inhibits migratory and invasive potential of various tumor cells

Sec62 is part of the protein translocation apparatus in the membrane of the endoplasmic reticulum (ER). In yeast, Sec62 participates in the post-translational translocation of proteins into the ER, but its function in mammals remains elusive. Previously we described the amplification and over-expression of the SEC62 gene in prostate cancer cell lines and the protein has been described as a potential target gene in prostate cancer. In the current study we show that in the tumor tissue of prostate cancer patients Sec62 protein levels are elevated compared with tumor-free tissue derived from the same patients or from prostates of control group patients and that the higher Sec62 protein content correlates with an increasing de-differentiation of the cells. Therefore, up-regulation of Sec62 protein content indeed is a phenomenon associated with prostate cancer progression. Analysis of a multi-tissue tumor array showed that in addition to prostate cancer, overproduction of Sec62 is observed in various other tumors, most significantly in tumors of the lung and the thyroid. To examine the tumor-related functions of Sec62, we silenced the SEC62 gene in the prostate cancer cell-line PC3 as well as in a set of other tumor cell-lines with two different siRNAs. In general, after silencing of SEC62 the cell migration and the invasive potential of the cells was blocked or at least dramatically reduced while cell viability was hardly affected. Thus, the SEC62 gene may indeed be considered as a target gene in the therapy of various tumors

Optimal Management of Prostate Cancer Based on its Natural Clinical History

Prostate cancer is the most common malignancy in males and, despite a marked improvement in diagnostic techniques, a not small percentage of prostate tumours is still diagnosed in advanced stage. It is now clear that prostate cancer passes through distinct phases during its natural history, starting from an initial phase, in which the disease has a locoregional extent, until a very late phase when it becomes refractory to hormone therapy. It is important to distinguish between local disease, in which tumor may be considered localized in the gland and a systemic disease characterized by high tumor burden and/or dissemination of circulating tumour cells. All the prostate cancers, at first diagnosis, are characterized by high sensitivity to the androgen deprivation therapy (ADT); however, during the natural history, after a variable period, they become castration resistant. In the past, few therapy options were available for castration resistant prostate cancer, while at present much more approaches can be employed, both hormone-based therapies and chemotherapy regimens. Hypercastration agents are defined as drugs capable to target the androgen-androgen receptor axis even in castrate resistant conditions. Abiraterone and enzalutamide are the only two hypercastration agents available for clinical use. Osteoclast targeted agents, such as zoledronic acid and denosumab can always been employed, but their use should be limited to the castrate resistant setting. The optimal understanding of all phases characterizing the natural history of prostate cancer may certainly be useful for the selection of the best therapeutic options in prostate cancer

Effect of Cecropin B on cell membranes of 486P bladder cancer cells and ZF07 fibroblasts as visualized by scanning electron microscopy (SEM)

Representative example of an untreated 486P bladder cancer cell showing a smooth surface. 486P cells treated with 65 μM Cecropin B reveal a disrupted cell membrane with only small islands of intact surface left (arrow). In contrast, untreated ZF07 fibroblasts and () fibroblasts after incubation with 65 μM Cecropin B do not display any changes in cell morphology with no observable damage to the cell membrane.<p><b>Copyright information:</b></p><p>Taken from "Antimicrobial peptides of the Cecropin-family show potent antitumor activity against bladder cancer cells"</p><p>http://www.biomedcentral.com/1471-2490/8/5</p><p>BMC Urology 2008;8():5-5.</p><p>Published online 3 Mar 2008</p><p>PMCID:PMC2276511.</p><p></p