CK2 abrogates the inhibitory effects of PRH/HHEX on prostate cancer cell migration and invasion and acts through PRH to control cell proliferation.

PRH/HHEX (proline-rich homeodomain protein/haematopoietically expressed homeobox protein) is a transcription factor that controls cell proliferation, cell differentiation and cell migration. Our previous work has shown that in haematopoietic cells, Protein Kinase CK2-dependent phosphorylation of PRH results in the inhibition of PRH DNA-binding activity, increased cleavage of PRH by the proteasome and the misregulation of PRH target genes. Here we show that PRH and hyper-phosphorylated PRH are present in normal prostate epithelial cells, and that hyper-phosphorylated PRH levels are elevated in benign prostatic hyperplasia, prostatic adenocarcinoma, and prostate cancer cell lines. A reduction in PRH protein levels increases the motility of normal prostate epithelial cells and conversely, PRH over-expression inhibits prostate cancer cell migration and blocks the ability of these cells to invade an extracellular matrix. We show that CK2 over-expression blocks the repression of prostate cancer cell migration and invasion by PRH. In addition, we show that PRH knockdown in normal immortalised prostate cells results in an increase in the population of cells capable of colony formation in Matrigel, as well as increased cell invasion and decreased E-cadherin expression. Inhibition of CK2 reduces PRH phosphorylation and reduces prostate cell proliferation but the effects of CK2 inhibition on cell proliferation are abrogated in PRH knockdown cells. These data suggest that the increased phosphorylation of PRH in prostate cancer cells increases both cell proliferation and tumour cell migration/invasion.

Biliary epithelial senescence and plasticity in acute cellular rejection.

Biliary epithelial cells (BEC) are important targets in some liver diseases, including acute allograft rejection. Although some injured BEC die, many can survive in function compromised states of senescence or phenotypic de-differentiation. This study was performed to examine changes in the phenotype of BEC during acute liver allograft rejection and the mechanism driving these changes. Liver allograft sections showed a positive correlation (p < 0.0013) between increasing T cell mediated acute rejection and the number of BEC expressing the senescence marker p21(WAF1/Cip) or the mesenchymal marker S100A4. This was modeled in vitro by examination of primary or immortalized BEC after acute oxidative stress. During the first 48 h, the expression of p21(WAF1/Cip) was increased transiently before returning to baseline. After this time BEC showed increased expression of mesenchymal proteins with a decrease in epithelial markers. Analysis of TGF-ß expression at mRNA and protein levels also showed a rapid increase in TGF-ß2 (p < 0.006) following oxidative stress. The epithelial de-differentiation observed in vitro was abrogated by pharmacological blockade of the ALK-5 component of the TGF-ß receptor. These data suggest that stress induced production of TGF-ß2 by BEC can modify liver allograft function by enhancing the de-differentiation of local epithelial cells.

Antiretroviral regimens for patients with HIV who fail first-line antiretroviral therapy.

BACKGROUND: Highly active antiretroviral therapy has reduced the morbidity and mortality of patients with HIV/AIDS. A common first-line ART regimen includes a non-nucleoside reverse transcriptase inhibitor (NNRTI) and two nucleoside reverse transcriptase inhibitors (NRTIs). If treatment failure occurs, a change to second-line therapy is necessary. OBJECTIVES: This meta-analysis aimed to assess the optimum antiretroviral regimen for patients with HIV who fail first-line therapy (ART-naive) with d4T+3TC+NVP; d4T+3TC+EFV; ZDV+3TC+NVP; and ZDV+3TC+EFV. SEARCH STRATEGY: Electronic databases and conference proceedings were searched with relevant search terms without limits to language. SELECTION CRITERIA: Randomised controlled trials of HIV-infected adult patients administered second-line ART after virologic failure of a first-line regimen were included. The primary outcome measure included the proportion of patients achieving undetectable plasma HIV RNA concentration (viral load). Secondary outcome measures included change in mean CD4 cell count, clinical resolution of symptoms, rate of adverse events, rate of change in therapy for failure, rate of change in therapy for toxicity, and mortality. DATA COLLECTION AND ANALYSIS: Two authors assessed each reference for inclusion and exclusion criteria established a priori. Data were abstracted independently using a standardised abstraction form. MAIN RESULTS: Twenty-one records were identified in total, 6 of which were duplicates. None of the records met inclusion criteria. AUTHORS' CONCLUSIONS: There is insufficient evidence to evaluate second-line therapies in patients with HIV who fail first-line treatment with d4T+3TC+NVP; d4T+3TC+EFV; ZDV+3TC+NVP; and ZDV+3TC+EFV. Current recommendations are based on available resources and results from individualised treatment decisions based on resistance testing and clinician choice.