Purinergic Receptor Expression and Cellular Responses to Purinergic Agonists in Human Prostate Cancer Cells.

BACKGROUND: Anticancer activity of extracellular nucleotides has been investigated in many types of cancer. Herein, the effects of extracellular nucleotides and the receptor profile for these nucleotides on prostate cancer (PCa) were elaborated. MATERIALS AND METHODS: PCa cell lines representing different stages of PCa were used. The effects of ATP and adenosine on PCa growth and migration on different extracellular matrix proteins were examined by MTT and wound-healing assays. Purinergic receptor profiling was carried out by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: A growth-inhibitory effect of ATP and adenosine was observed on all PCa cell lines tested. Several ATP-recognized P2 receptors and adenosine receptors were commonly expressed in PCa cell lines. Neither ATP nor adenosine had any significant effect on PCa migration. CONCLUSION: ATP and adenosine had an antiproliferative effect on PCa cells without affecting their motility, indicating their potential as a novel therapy for PCa.

Selection of a recombinant Marek's disease virus in vivo through expression of the Marek's EcoRI-Q (Meq)-encoded oncoprotein: characterization of an rMd5-based mutant expressing the Meq of strain RB-1B.

Marek's disease (MD) is a highly contagious viral disease of chickens (Gallus gallus domesticus) caused by MD virus (MDV), characterized by paralysis, neurologic signs, and the rapid onset of T-cell lymphomas. MDV-induced T-cell transformation requires a basic leucine zipper protein called Marek's EcoRI-Q-encoded protein (Meq). We have identified mutations in the coding sequence of Meq that correlated with virus pathotype (virulent, very virulent, and very virulent plus). The aim of this study was to determine whether recombinant viruses could be isolated based on Meq expression through in vivo selection. Chicken embryo fibroblasts (CEFs) were cotransfected with an rMd5 strain-based Meq deletion virus (rMd5deltaMeq) and meq loci from strains representing different pathotypes of MDV. Transfected CEFs were inoculated into chickens in two independent studies. We were able to isolate a single recombinant virus, rMDV-1137, in a contact-exposed chicken. rMDV-1137 had recombined two copies of the meq gene of RB-1B and was found to have pathogenicity similar to both RB-1B and rMd5 parental strains. We found the RB-1B- and rMd5-induced lymphomas showed differences in composition and that rMDV-1137-induced lymphomas were intermediate in their composition. We were able to establish cell lines from both RB-1B- (MDCC-UD35, -UD37) and rMDV-1137 (MDCC-UD36, -UD38)-induced, but not rMd5-induced, lymphomas. To date, no rMd5- or parent Md5-transformed T-cell lines have been reported. Our results suggest that 1) a recombinant MDV can be selected on the basis of oncogenicity; 2) changes in Meq sequence seem to affect tumor composition and the ability to establish cell lines; and 3) in addition to meq, other genomic loci affect MDV pathogenicity and oncogenicity.