Previous studies of p53 have implicated cysteine residues in site-specific DNA binding via zinc coordination and redox regulation (P. Hainaut J. Milner, Cancer Res. 53:4469-4473, 1993; T. R. Hupp, D. W. Meek, C. A. Midgley, P. Lane, Nucleic Acids 21:3167-3174, 1993). We show here that are, at least part, distinct determinants the to DNA. Moreover, by substituting serine for each murine p53, we investigated roles individual cysteines function. Substitution position 40, 179, 274, 293, or 308...

AbstractWe have analyzed the specific interaction of murine p53 with consensus DNA-binding sequence 5′-AGACATGCCT-AGACATGCCT-3′. We used segments lacking C-terminal, nonspecific domain because presence an autonomous in wild-type would complicate analysis site-specific DNA binding. amino acids 1 to 360 bind as tetramers, and binding promotes tetramer-tetramer interactions. 80 290, both tetramerization domains, consistently four monomers only monomers. The virtual absence stable by fewer than...

Abstract We have used gradient gel electrophoresis and chemical cross‐linking to analyze the quaternary structure of purified, wild‐type, murine p53. Under nondenaturing conditions, p53 electrophoreses as tetramers multiples tetramers. denaturing fully cross‐linked also behaves tetrameric structures. confirmed composition by partially dissociating into monomers, dimers, trimers. © 1992 wiley‐Liss, Inc.

The objective of this study was to determine if repeated impact could damage living cartilage and lead osteoarthritis-like changes in its biology. Canine explants were subjected impacts as much 50 MPa once every 5 seconds for 30 minutes. On each cycle, the loading rate 100 MPa/sec assigned peak stress, which held 1 second. After testing, kept defined culture long 10 days. Radiosulfate incorporation region that received direct varied with load 0-4 hours after impact, but it did not vary at...

The effect of phosphorylation on the ability simian virus 40 large T antigen to stimulate DNA synthesis in vitro was tested. Treatment affinity-purified with calf intestinal alkaline phosphatase resulted removal 70 80% phosphate residues. Only serine-bound residues were affected. Phosphatase-treated stimulated fourfold over untreated control. stimulation strongest at early times replication. At later times, replication proceeded equal rates dephosphorylated and antigen. ATPase activity not...

Background: Mucin-1 (MUC1) is a glycoprotein that hypoglycosylated and overexpressed in most adenocarcinomas, making it promising target for cancer vaccines. Our group previously demonstrated C3 (OPSS)-liposomes enhance antigen uptake by antigen-presenting cells (APCs) via the complement pathway and, when combined with toll-like receptor (TLR) agonists, reduce tumor growth murine models. Methods: In present study, we evaluate immunogenicity of MUC1 peptide vaccines encapsulated C3-liposomes,...

HeLa cells infected with the nondefective adenovirus 2 (Ad2)-simian virus 40 (SV40) hybrid viruses (Ad2 + ND1, Ad2 ND2, ND4, and ND5) synthesize SV40-specific proteins ranging in size from 28,000 to 100,000 daltons. By analysis of their methionine-containing tryptic peptides, we demonstrated that all these shared common amino acid sequences. Most peptides derived smaller were contained within larger size. Seventeen 21 largest protein (100,000 daltons) ND4-infected identical SV40 T-antigen...

Viral nucleoprotein complexes were extracted from the nuclei of simian virus 40 (SV40)-infected TC7 cells by low-salt treatment in absence detergent, followed sedimentation on neutral sucrose gradients. Two forms SV40 complexes, those containing replicative intermediate DNA and (I) DNA, separated one another found to have values 125 93S, respectively. [ 35 S]methioninelabeled proteins analyzed sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In addition VP1, VP3, histones, a...

Bleomycin is a membrane impermeable chemotherapeutic agent that relatively innocuous extracellularly but highly cytotoxic when delivered directly to the cytoplasm. We report on development of liposome delivery system targets Her-2 overexpressing breast cancer cells and breaches endosomal barrier, delivering bleomycin The liposomes are conjugated antibody trastuzumab, which results in specific binding internalization into cells. In addition, disulfide bonded pore-forming protein listeriolysin...

To enhance cytoplasmic delivery of liposomal contents to breast cancer cells, the authors have attached pore-forming protein, listeriolysin O (LLO), thermosensitive liposomes. The antibody trastuzumab (Herceptin®) was also conjugated with outer surface liposomes, resulting in highly specific binding and internalization into mammary epithelial cells that overexpress human epidermal growth factor receptor 2 (Her-2). liposomes were preloaded a marker fluorescent dye, effect LLO on distribution...

We report on a new method for enhancing the specificity of drug delivery tumor cells, using thermosensitive immunoliposomes. The liposomes are conjugated to antibody trastuzumab (Herceptin), which targets human epidermal growth factor receptor 2 (Her-2), cell membrane overexpressed in many cancers. Being thermosensitive, only release their contents when heated slightly above body temperature, allowing possibility tissue targeting through localized hyperthermia. Using self-quenching calcein,...

Complement C3-dependent uptake of targeted liposomes into human macrophages, B cells, dendritic neutrophils, and MDSCs Alexandra Francian,1 Kristine Mann,1,2 Max Kullberg1 1WWAMI Medical Education Program, 2Department Biological Sciences, University Alaska Anchorage, AK, USA Abstract: Antitumor immunity in cancer patients is heavily modulated by cells the innate immune system. Antigen-presenting including initiate recognition tumor antigen displaying to effector cells. Countering this...

We describe a novel gene delivery system that specifically targets human epidermal growth factor receptor 2 (Her2)-overexpressing breast cancer cells. The targeting complexes consist of PEGylated polylysine core is bound to DNA molecules coding for either green fluorescent protein or shrimp luciferase. complex disulfide linked the monoclonal antibody trastuzumab and pore-forming protein, Listeriolysin O (LLO). Trastuzumab responsible specific Her2 receptors uptake into endosomes recipient...

Mucin-1 (MUC1) is a highly relevant antigen for cancer vaccination due to its overexpression and hypo-glycosylation in high percentage of carcinomas. To enhance the immune response MUC1, our group has developed C3-liposomes that encapsulate MUC1 along with immunostimulatory compounds direct delivery antigen-presenting cells (APCs). bind complement C3, which interacts C3-receptors on APCs, resulting liposomal uptake tumor antigens APCs manner mimics pathogenic uptake. In this study, Toll-like...

The time course of expression topoisomerase I, II, and simian virus 40 (SV40) large tumor (T) antigen was determined in whole-cell extracts uninfected versus SV40-infected TC7 cells. After a minor increase, the level I remained fairly constant throughout both In contrast, II increased markedly cells but not following appearance SV40 T antigen.

In the tumor microenvironment, cytokines, growth factors, and oncogenes mediate constitutive activation of signal transducer activator transcription 3 (STAT3) signaling pathway in both cancer cells infiltrating immune cells. STAT3 drives tumorigenic changes that allow for increased survival, proliferation, resistance to apoptosis. The modulation is more complicated conflicting. myeloid cell phenotype towards an suppressive state, which mediates T inhibition. On other hand, leads...