Array-based analysis of the effects of trichostatin A and CG-1521 on cell cycle and cell death in LNCaP prostate cancer cells.

Previous studies comparing the effects of two histone deacetylase (HDAC) inhibitors, trichostatin A (TSA) and CG-1521, have shown that these compounds selectively inhibit HDAC and induce differentially acetylated p53 isoforms and assembly of mutually exclusive transcriptional complexes on the p21 promoter. To determine whether the differential transcriptional regulation seen in p21 gene is unique or whether it is representative of the genome-wide effects of these two HDAC inhibitors, we have used microarray and Ingenuity pathway analysis to compare the effects of TSA and CG-1521 on gene expression on LNCaP cells. Gene array analysis confirmed by quantitative real-time PCR shows that CG-1521 modulates the expression of a highly circumscribed group of genes involved in cell cycle progression and cell death. In contrast, TSA appears to induce widespread transrepression of many genes and does not modulate the expression of the same cohort as CG-1521. These data show that the selective effects of CG-1521 and TSA on the assembly of transcription complexes are not unique to the p21 gene and suggest that selective inhibition of HDAC can lead to significant changes in gene expression through the acetylation of transcription factors including but not limited to p53.

Effects of Iejimalide B, a marine macrolide, on growth and apoptosis in prostate cancer cell lines.

Iejimalide B, a marine macrolide, causes growth inhibition in a variety of cancer cell lines at nanomolar concentrations. We have investigated the effects of Iejimalide B on cell cycle kinetics and apoptosis in the p53+/AR+ LNCaP and p53-/AR- PC-3 prostate cancer cell lines. Iejimalide B, has a dose and time dependent effect on cell number (as measured by crystal violet assay) in both cell lines. In LNCaP cells Iejimalide B induces a dose dependent G0/G1 arrest and apoptosis at 48 h (as measured by Apo-BrdU staining). In contrast, Iejimalide B initially induces G0/G1 arrest followed by S phase arrest but does not induce apoptosis in PC-3 cells. qPCR and Western analysis suggests that Iejimalide B modulates the steady state level of many gene products associated with cell cycle (including cyclins D, E, and B and p21(waf1/cip1)) and cell death (including survivin, p21B and BNIP3L) in LNCaP cells. In PC-3 cells Iejimalide B induces the expression of p21(waf1/cip1), down regulates the expression of cyclin A, and does not modulate the expression of the genes associated with cell death. Comparison of the effects of Iejimalide B on the two cell lines suggests that Iejimalide B induces cell cycle arrest by two different mechanisms and that the induction of apoptosis in LNCaP cells is p53-dependent.

Comparing two strategies for emergency department chest pain patients: immediate computed tomography coronary angiography versus delayed outpatient treadmill testing.

Chest pain (CP) is a common emergency department (ED) complaint and return visits (recidivism) are common. Recidivism may be related to incomplete evaluation of a patient's complaint. Computed tomography coronary angiography (CTCA) is accurate for diagnosing coronary artery disease (CAD) in patients with CP. We will compare a strategy of immediate CTCA with a strategy of delayed outpatient stress testing and hypothesize that CTCA will reduce recidivism in patients with CP. We conducted a retrospective cohort study comparing strategies for ED patients with CP: immediate CTCA (CT cohort) versus delayed outpatient stress testing (control cohort). Two hundred eighty subjects were included, 140 in each of the strategies. Recidivism within 6 months of the index ED evaluation occurred in 12 subjects from the CT cohort and 18 subjects from the control cohort (9% vs. 13%, P = 0.41). Duration of stay was increased in the CT cohort (456 vs. 417 min, P = 0.031). Immediate CTCA was associated with improved detection of obstructive CAD (8% vs. 1%, P = 0.005). In conclusion, immediate CTCA, when compared with delayed outpatient stress testing, did not reduce ED recidivism for CP. Length of stay was increased in the immediate CTCA cohort. The use of CTCA improved detection of obstructive CAD.

Prevention of human PC-346C prostate cancer growth in mice by a xenogeneic tissue vaccine.

Vaccination, as an approach to prostate cancer, has largely focused on immunotherapy utilizing specific molecules or allogeneic cells. Such methods are limited by the focused antigenic menu presented to the immune system and by immunotolerance to antigens recognized as "self". To examine if a xenogeneic tissue vaccine could stimulate protective immunity in a human prostate cancer cell line, a vaccine was produced by glutaraldehyde fixation of harvested PAIII prostate cancer cells tumors (GFT cell vaccine) from Lobund-Wistar rats. Immunocompetent Ncr-Foxn1 mice were vaccinated with the GFT cell vaccine four times, 7 days apart. The control animals were either not vaccinated or vaccinated with media or glutaraldehyde-fixed PC346C human prostate cancer cells and adjuvant. About 8 days after the final boost, serum and spleens were harvested. The splenocytes were co-incubated with PC346C cells and then transplanted orthotopically into sygneneic immunodeficient nude mice. About 10 weeks later, the prostates were weighed and sampled for histolologic examination. The spleens were harvested from additional mice, and the splenocytes were cultured, either with or without pulsing by GFT cells, and the supernatants harvested 72 h later for cytokine analysis. Results showed that vaccination with GFT cells resulted in increased serum antibody to a PAIII cell lysate; reduced weight of the prostate/seminal vesicle complex and reduced incidence of prostate cancer in nude mice; increased splenocyte supernatant levels of TNF-alpha, IL-2, IFN-gamma and IL-12, cytokines associated with Th1 immunity; and increased splenocyte supernatant levels of IL-4 and IL-10, cytokines associated with Th2 immunity. In summary, the results suggest that use of a xenogeneic tissue vaccine can stimulate protective immunity against human prostate cancer cells.