Therapeutic potential of parkin as a tumor suppressor via transcriptional control of cyclins in glioblastoma cell and animal models.

Parkin (PK) is an E3-ligase harboring tumor suppressor properties that has been associated to various cancer types including glioblastoma (GBM). However, PK is also a transcription factor (TF), the contribution of which to GBM etiology remains to be established. The impact of PK on GBM cells proliferation was analyzed by real-time impedance measurement and flow cytometry.

The human WNT5A isoforms display similar patterns of expression but distinct and overlapping activities in normal human osteoblasts.

WNT5A activates noncanonical Wnt signaling pathways and has critical functions in early development, differentiation, and tissue homeostasis. Two major WNT5A protein isoforms, which in this study we term WNT5A-L(A) and WNT5A-S(B), have been identified that differ by 18 AA at their amino terminus. Functional differences between the isoforms have been indicated in studies utilizing cancer cell lines but the activities of the isoforms in normal cells and during differentiation have not been explored.

Inactivation of the WNT5A Alternative Promoter B Is Associated with DNA Methylation and Histone Modification in Osteosarcoma Cell Lines U2OS and SaOS-2.

WNT5A is a secreted ligand involved in Wnt pathway signaling and has a role in cell movement and differentiation. Altered WNT5A expression is associated with various cancers, although in most studies the focus has been on only one of the known WNT5A isoforms. In this study, we analyzed expression from two of the major WNT5A promoters, termed promoter A and promoter B, in normal human osteoblasts, SaOS-2 and U2OS osteosarcoma cell lines, and osteosarcoma tumor tissue.

Differential regulation of the mouse and human Wnt5a alternative promoters A and B.

Wnt5a is an extracellular glycoprotein that activates Wnt signaling pathways, important in development and tissue homeostasis. Wnt5a expression is often misregulated during cancer progression. In this study, we analyzed the transcriptional regulation of two of the Wnt5a alternative promoters, termed A and B.

Effects of various polyphenolics on hydrogen peroxide-induced p53 activity in NIH3T3 cells.

A cell-based assay system was developed to evaluate the potential antioxidant and pro-oxidant effects of various dietary polyphenolic compounds based on the induction of p53 activity by hydrogen peroxide. A p53-luciferase reporter vector was stably transfected into NIH3T3 cells. Individual clones were isolated, and one clone (number 33) was selected that showed the highest induction levels with different generators of free radicals.

Folate deficiency in normal human fibroblasts leads to altered expression of genes primarily linked to cell signaling, the cytoskeleton and extracellular matrix.

The molecular basis linking folate deficiency to certain health conditions and developmental defects is not fully understood. We examined the consequences of folate deficiency on global gene expression by microarray and compared transcript levels in normal human fibroblast cells (GM03349) grown in folate-deficient and -sufficient medium. The largest represented groups from the selected genes functioned in cell signaling, the cytoskeleton and the extracellular matrix and included the Wnt pathway genes DKK1, WISP1 and WNT5A.

Relative ability of dietary compounds to modulate nuclear factor-kappaB activity as assessed in a cell-based reporter system.

The ability of various dietary compounds to modulate the activity of the transcription factor nuclear factor kappaB (NF-kappaB) was examined using a cell-based reporter system. NF-kappaB is central to the response of cells to stress and has been linked to cancer. HCT 116 (human colon carcinoma) and HepG2 (human liver carcinoma) cell lines were stably transfected with a NF-kappaB luciferase reporter vector.

Cell cycle specific changes in the human cyclin B1 gene regulatory region as revealed by response to trichostatin A.

The human cyclin Bl gene is cell cycle regulated with maximal activity during G(2)/M. We examined the role of histone deacetylation in cyclin Bl regulation using the histone deacetylase inhibitor trichostatin A (TSA). TSA treatment (100 ng/ml) of NIH3T3 cells containing the luciferase reporter construct pCycB(-287)-LUC caused an increase in promoter activity in G(0) and G(1) but no significant change in G(2).

Cyclin b1 promoter activity and functional cdk1 complex formation in G1 phase of human breast cancer cells.

Overexpression of cyclin B has been detected in various human breast cancer cell lines, breast tumor tissues, and immortalized but nontransformed breast cells. The cause of this overexpression has not been thoroughly investigated, nor is it known if cyclin B protein forms a functional complex with its partner, cdk1, at inappropriate cell cycle periods. In this study we examined the pattern of cyclin B1 promoter activity in three breast cancer cell lines, BT-549, MDA-MB-157, T-47D, and the immortalized breast cell line MCF-10F.

Spatial Pattern of Expression of Cyl Actin-β-Galactosidase Fusion Genes injected into Sea Urchin Eggs.

The Cyl actin gene of the sea urchin Strongylocentrotus purpuratus displays a pattern of expression that is correlated with cell division; the gene is initially activated in all cells of the early blastula stage embryo, but after 18 hours Cyl actin transcripts disappear from the aboral ectoderm at a time when these cells are withdrawing from the cell cycle. As part of our investigation of the transcriptional regulation of Cyl, we tested various Cyl-β-gal fusion genes for their spatial pattern of expression by microinjection into fertilized eggs of the sea urchin, Lytechinus pictus. The plasmid Cyl-β-gal containing 2.