Rad9 modulates the P21WAF1 pathway by direct association with p53

<p>Abstract</p> <p>Background</p> <p>Previous studies suggest that human <it>RAD9 </it>(hRad9), encoding a DNA damage checkpoint molecule, which is frequently amplified in epithelial tumor cells of breast, lung, head and neck cancer, participates in regulation of the tumor suppressor p53-dependent transactivation of pro-survival <it>P21</it>^{<it>WAF1</it>}. This study examined the exact mechanism of the hRad9 function, especially through the phosphorylation of the C-terminus, in the transcription regulation of <it>P21</it>^{<it>WAF1</it>}.</p> <p>Results</p> <p>The transfection of phosphorylation-defective <it>hRAD9 </it>mutants of C-terminus resulted in reduction of the p53-dependent <it>P21</it>^{<it>WAF1 </it>}transactivation; the knockdown of total hRad9 elicited an increased <it>P21</it>^{<it>WAF1 </it>}mRNA expression. Immunoprecipitation and a ChIP assay showed that hRad9 and p53 formed a complex and both were associated with two p53-consensus DNA-binding sequences in the 5' region of <it>P21</it>^{<it>WAF1 </it>}gene. The association was reduced in the experiment of phosphorylation-defective <it>hRAD9 </it>mutants.</p> <p>Conclusion</p> <p>The present study indicates the direct involvement of hRad9 in the p53-dependent <it>P21</it>^{<it>WAF1 </it>}transcriptional mechanism, presumably via the phosphorylation sites, and alterations of the hRad9 pathway might therefore contribute to the perturbation of checkpoint activation in cancer cells.</p

Cytopathic effects and local immune responses in repeated neoadjuvant HSV-tk + ganciclovir gene therapy for prostate cancer

ObjectiveCytopathic effects and local immune response were analyzed histologically in prostatic carcinoma (PCa) with in situ herpes simplex virus-thymidine kinase (HSV-tk)/ganciclovir (GCV) gene therapy (GT). MethodsFour high-risk PCa patients who received HSV-tk/GCV GT were investigated. After two cycles of intraprostatic injection of HSV-tk and administration of GCV, radical prostatectomy was performed. Formalin-fixed, paraffin-embedded sections were evaluated using immunohistochemistry. PCa with hormone therapy (HT, n = 3) or without neoadjuvant therapy (NT, n = 4) that were equivalent in terms of risk were also examined as reference. Immunoreactively-positive cells were counted in at least three areas in cancer tissue. Labeling indices (LI) were calculated as percentage values. ResultsssDNA LI in GT increased, indicating apoptosis, as well as tumor-infiltrating lymphocytes and CD68-positive macrophages, compared with their biopsies. GT cases showed significantly higher numbers of ssDNA LI, CD4/CD8-positive T cells and CD68-positive macrophages including M1/M2 macrophages than HT or NT cases. However, there was no significant difference in CD20-positive B cells among the types of case. There were strong correlations between CD8+ T cells and CD68+ macrophages (ρ = 0.656, p < 0.0001) as well as CD4+ T cells and CD20+ B cells (ρ = 0.644, p < 0.0001) in PCa with GT. ConclusionsEnhanced cytopathic effect and local immune response were might be indicated in PCa patients with HSV-tk/GCV gene therapy.Cytopathic effects and local immune response were analyzed histologically in prostatic carcinoma (PCa) with in situ herpes simplex virus-thymidine kinase (HSV-tk)/ganciclovir (GCV) gene therapy (GT..

GDNF-inducible zinc finger protein 1 is a sequence-specific transcriptional repressor that binds to the HOXA10 gene regulatory region

The RET tyrosine kinase receptor and its ligand, glial cell line-derived neurotrophic factor (GDNF) are critical regulators of renal and neural development. It has been demonstrated that RET activates a variety of downstream signaling cascades, including the RAS/mitogen-activated protein kinase and phosphatidylinositol-3-kinase(PI3-K)/AKT pathways. However, nuclear targets specific to RET-triggered signaling still remain elusive. We have previously identified a novel zinc finger protein, GZF1, whose expression is induced during GDNF/RET signaling and may play a role in renal branching morphogenesis. Here, we report the DNA binding property of GZF1 and its potential target gene. Using the cyclic amplification and selection of targets technique, the consensus DNA sequence to which GZF1 binds was determined. This sequence was found in the 5′ regulatory region of the HOXA10 gene. Electrophoretic mobility shift assay revealed that GZF1 specifically binds to the determined consensus sequence and suppresses transcription of the luciferase gene from the HOXA10 gene regulatory element. These findings thus suggest that GZF1 may regulate the spatial and temporal expression of the HOXA10 gene which plays a role in morphogenesis

Anti-tumor effects of interferon-beta cell therapy in murine model of melanoma

Purpose: Recombinant interferon beta (IFN-β) has been used for a treatment of cancers. However, the efficacy of recombinant IFN-β is limited because of its short half-life and side effects. To overcome these problems, we focused on the efficacy of cell-based therapy (cell therapy) using IFN-β-producing cells in the treatment of melanoma.Methods: IFN-β-producing therapeutic cells were constructed by gene transduction using retrovirus vector. Anti-tumor effects of the cell therapy were investigated by a murine melanoma model.Results: IFN-β cell therapy significantly suppressed the proliferation of B16 melanoma in vitro and the growth of B16-derived tumor in vivo, accompanied with the activation of natural killer (NK) cells. IFN-β cell therapy did not show any systemic side-effects concerning hepatic dysfunction and bone marrow suppression.Conclusion: IFN-β cell therapy could be a candidate as a novel cancer treatment.

Regulation of cargo-selective endocytosis by dynamin 2 GTPase-activating protein girdin.

In clathrin-mediated endocytosis (CME), specificity and selectivity for cargoes are thought to be tightly regulated by cargo-specific adaptors for distinct cellular functions. Here, we show that the actin-binding protein girdin is a regulator of cargo-selective CME. Girdin interacts with dynamin 2, a GTPase that excises endocytic vesicles from the plasma membrane, and functions as its GTPase-activating protein. Interestingly, girdin depletion leads to the defect in clathrin-coated pit formation in the center of cells. Also, we find that girdin differentially interacts with some cargoes, which competitively prevents girdin from interacting with dynamin 2 and confers the cargo selectivity for CME. Therefore, girdin regulates transferrin and E-cadherin endocytosis in the center of cells and their subsequent polarized intracellular localization, but has no effect on integrin and epidermal growth factor receptor endocytosis that occurs at the cell periphery. Our results reveal that girdin regulates selective CME via a mechanism involving dynamin 2, but not by operating as a cargo-specific adaptor

Thermodynamic instability of siRNA duplex is a prerequisite for dependable prediction of siRNA activities

We developed a simple algorithm, i-Score (inhibitory-Score), to predict active siRNAs by applying a linear regression model to 2431 siRNAs. Our algorithm is exclusively comprised of nucleotide (nt) preferences at each position, and no other parameters are taken into account. Using a validation dataset comprised of 419 siRNAs, we found that the prediction accuracy of i-Score is as good as those of s-Biopredsi, ThermoComposition21 and DSIR, which employ a neural network model or more parameters in a linear regression model. Reynolds and Katoh also predict active siRNAs efficiently, but the numbers of siRNAs predicted to be active are less than one-eighth of that of i-Score. We additionally found that exclusion of thermostable siRNAs, whose whole stacking energy (ΔG) is less than −34.6 kcal/mol, improves the prediction accuracy in i-Score, s-Biopredsi, ThermoComposition21 and DSIR. We also developed a universal target vector, pSELL, with which we can assay an siRNA activity of any sequence in either the sense or antisense direction. We assayed 86 siRNAs in HEK293 cells using pSELL, and validated applicability of i-Score and the whole ΔG value in designing siRNAs

Involvement of Girdin in the Determination of Cell Polarity during Cell Migration

Cell migration is a critical cellular process that determines embryonic development and the progression of human diseases. Therefore, cell- or context-specific mechanisms by which multiple promigratory proteins differentially regulate cell migration must be analyzed in detail. Girdin (girders of actin filaments) (also termed GIV, Gα-interacting vesicle associated protein) is an actin-binding protein that regulates migration of various cells such as endothelial cells, smooth muscle cells, neuroblasts, and cancer cells. Here we show that Girdin regulates the establishment of cell polarity, the deregulation of which may result in the disruption of directional cell migration. We found that Girdin interacts with Par-3, a scaffolding protein that is a component of the Par protein complex that has an established role in determining cell polarity. RNA interference-mediated depletion of Girdin leads to impaired polarization of fibroblasts and mammary epithelial cells in a way similar to that observed in Par-3-depleted cells. Accordingly, the expression of Par-3 mutants unable to interact with Girdin abrogates cell polarization in fibroblasts. Further biochemical analysis suggests that Girdin is present in the Par protein complex that includes Par-3, Par-6, and atypical protein kinase C. Considering previous reports showing the role of Girdin in the directional migration of neuroblasts, network formation of endothelial cells, and cancer invasion, these data may provide a specific mechanism by which Girdin regulates cell movement in biological contexts that require directional cell movement

CD109 and squamous cell carcinoma

Abstract Squamous cell carcinoma (SCC) is well-known for its high rate of metastasis with poor prognosis. CD109 is a glycosylphosphatidylinositol-anchored cell-surface glycoprotein. Recently, CD109 emerges as a potential biomarker and a therapeutic target for SCCs. Accumulating studies have reported that CD109 is highly expressed in human SCCs of multiple organs, and may contribute to the progression of SCCs. In this review, we summarized the findings on expression pattern of CD109 in SCCs, and discussed the molecular mechanisms underlying the roles of CD109 in pathogenesis of SCCs

A Targeting Mutation of Tyrosine 1062 in Ret Causes a Marked Decrease of Enteric Neurons and Renal Hypoplasia

The Ret receptor tyrosine kinase plays a crucial role in the development of the enteric nervous system and the kidney. Tyrosine 1062 in Ret represents a binding site for the phosphotyrosine-binding domains of several adaptor and effector proteins that are important for the activation of intracellular signaling pathways, such as the RAS/ERK, phosphatidylinositol 3-kinase/AKT, and Jun-associated N-terminal kinase pathways. To investigate the importance of tyrosine 1062 for organogenesis in vivo, knock-in mice in which tyrosine 1062 in Ret was replaced with phenylalanine were generated. Although homozygous knock-in mice were born normally, they died by day 27 after birth and showed growth retardation. The development of the enteric nervous system was severely impaired in homozygous mutant mice, about 40% of which lacked enteric neurons in the whole intestinal tract, as observed in Ret-deficient mice. The rest of the mutant mice developed enteric neurons in the intestine to various extents, although the size and number of ganglion cells were significantly reduced. Unlike Ret-deficient mice, a small kidney developed in all knock-in mice, accompanying a slight histological change. The reduction of kidney size was due to a decrease of ureteric bud branching during embryogenesis. Thus, these findings demonstrated that the signal via tyrosine 1062 plays an important role in histogenesis of the enteric nervous system and nephrogenesis