Chemosensitization of Prostate Carcinoma Cells with a Receptor-directed Smac Conjugate.

Background: Second mitochondrial activator of caspase (Smac) is a short mitochondrial peptide. When released from the mitochondria into the cytoplasm, it binds to inhibitor of apoptotic proteins (IAPs) within the cytoplasm and prevents them from inhibiting apoptosis.

Objective: Delivery of external synthetic Smac peptide into the cytoplasm of malignant cells could greatly improve the efficiency of apoptosis-inducing chemotherapeutic agents.

The gastrin/cholecystokinin-B receptor on prostate cells--a novel target for bifunctional prostate cancer imaging.

The means of identifying prostate carcinoma and its metastases are limited. The contrast agents used in magnetic resonance imaging clinical diagnostics are not taken up into the tumor cells, but only accumulate in the interstitial space of the highly vasculated tumor. We examined the gastrin/cholecystokinin-B receptor as a possible target for prostate-specific detection using the C-terminal seven amino acid sequence of the gastrin peptide hormone.

Rhodamine-marked bombesin: a novel means for prostate cancer fluorescence imaging.

The gastrin releasing peptide receptor (GRPR) has been found to be strongly expressed in various types of cancers such as prostate and breast carcinomas. The GRPR ligands gastrin releasing peptide and bombesin can play a very significant role in cancer therapy and diagnostics. In this study we synthesized unlabeled bombesin BBN along with two conjugates in which the correct bombesin (BBN-Rhd) and a mutant bombesin (mBBN-Rhd) sequence was coupled to rhodamine, a fluorescent dye.

Ramoplanin imaging conjugates--synthesis and evaluation.

In a previous study we found that fluorescence-marked vancomycin--a glycopeptide antibiotic--is taken up into human tumor cells. To expand on these investigations we now used the lipoglycodepsipeptide antibiotic ramoplanin. Compared to vancomycin it is not only a bigger molecule, but it also has two potential binding sites for coupling to the imaging agents.

Novel bourgeonal fragrance conjugates for the detection of prostate cancer.

The methods used for detection of prostate cancer and prostate cancer lymph node metastases in medical diagnostics leave room for improvement. Currently, no means of identifying metastasized lymph nodes other than biopsies is available. Markers which are exclusively found on prostate cancer cells present a focal point for potential imaging methods.

Evaluating the diagnostic and chemotherapeutic potential of vancomycin-derived imaging conjugates.

The main use of glycopeptide antibiotics is treatment of infections which are resistant to the commonly used β- lactam antibiotics. Antitumor activity has also been reported for some glycopeptide antibiotics like bleomycin. In the present study we investigated the chemotherapeutic and diagnostic potential of two imaging agent derivatives of the glycopeptide antibiotic vancomycin.

Novel gastrin receptor-directed contrast agents - potential in brain tumor magnetic resonance imaging.

Magnetic resonance imaging (MRI) is presently the method of choice for detection of brain tumors. However, MRI alone is not conclusive. As the commonly used contrast agents do not bind to the cells and are not taken up into the cells, they generally do accumulate in regions where the blood-brain-barrier is disrupted.

Potential of the gastric motility drug lorglumide in prostate cancer imaging.

The use of tissue-specific receptor ligands is a promising approach for cancer diagnostics and therapy. Lorglumide, a highly effective competitive ligand for the cholecystokinine-A receptor (CCKRA) was conjugated to a fluorescent dye and a magnetic resonance imaging (MRI) contrast agent to obtain a bifunctional marker for tissue with high CCKRA expression. An intermediate conjugate containing only lorglumide and a fluorescent dye was also produced.

Using the neurotransmitter serotonin to target imaging agents to glioblastoma cells.

The neurotransmitter serotonin is involved in numerous bodily functions via seven different serotonin receptor subfamilies. Serotonin plays a role in gastrointestinal functions like intestinal secretion or peristalsis and neuropsychiatric events like depression or migraine. One of these subtypes has been found on glioblastoma cells, inducing growth promotion.

Peptides derived from the human laminin alpha4 and alpha5 chains exhibit antimicrobial activity.

Laminins are a family of heterotrimeric extracellular matrix glycoproteins in the basement membrane of different tissues and are composed of alpha, beta, and gamma chains. In mammals, five different alpha chains, three beta chains, and three gamma chains have been identified that assemble into 15 different laminins. Each alpha-chain possesses a C-terminal globular domain which can be subdivided into the five subdomains LG1-LG5.

Dermcidin-derived peptides show a different mode of action than the cathelicidin LL-37 against Staphylococcus aureus.

Dermcidin (DCD) is an antimicrobial peptide which is constitutively expressed in eccrine sweat glands. By postsecretory proteolytic processing in sweat, the DCD protein gives rise to anionic and cationic DCD peptides with a broad spectrum of antimicrobial activity. Many antimicrobial peptides induce membrane permeabilization as part of their killing mechanism, which is accompanied by a loss of the bacterial membrane potential.

Serum protein profiling by SELDI mass spectrometry: detection of multiple variants of serum amyloid alpha in renal cancer patients.

The molecular analysis of serum is an important field for the definition of potential diagnostic markers or disease-related protein alterations. Novel proteomic technologies such as the mass spectrometric-based surface-enhanced laser desorption/ionization (SELDI) ProteinChip technique facilitate a rapid and reproducible analysis of such protein mixtures and affords the researcher a new dimension in the search for biomarkers of disease. Here, we have applied this technology to the study of a cohort of serum samples from well-characterized renal cell carcinoma patients for the identification of such proteins by comparison to healthy controls.

Relationship between T and B cell responses to proinsulin in human type 1 diabetes.

In type 1 diabetes, humoral and cell-mediated responses to insulin and proinsulin are detectable. Autoantibodies to insulin are associated with impending disease in young individuals and are used as predictive markers to determine disease risk. The aim of this study was to investigate whether different cytokine patterns of cellular reactivity to insulin might serve as additional specific markers of disease maturation and might improve disease prediction in individuals at risk.

Identification of an in vitro insulin receptor substrate-1 phosphorylation site by negative-ion muLC/ES-API-CID-MS hybrid scan technique.

Recently, we reported a fast on-line alkaline micro-liquid chromatography/electrospray-atmospheric pressure ionization/collision-induced dissociation/mass spectrometric approach for sensitive phosphopeptide screening of a tryptic digested protein and subsequent characterization of the identified phosphopeptide. Based on this study, we now applied an improved method for the identification of phosphorylation sites in insulin receptor substrate 1, an important mediator in insulin signal transduction which was phosphorylated in vitro by protein kinase C-zeta. The approach consists of an on-line alkaline negative-ion micro-liquid chromatography/electrospray-atmospheric pressure ionization/collision-induced dissociation/mass spectrometric hybrid scan experiment using a triple-quadrupole mass spectrometer with fractionation and subsequent off-line nanoES-MS (ion trap) analysis of the phosphopeptide-containing fractions.

Detection of dermcidin-derived peptides in sweat by ProteinChip technology.

Recently, a novel antimicrobial peptide DCD-1, derived from the Dermcidin (DCD) gene and secreted by sweat glands, has been described by Schittek et al. [Nat. Immunol.

Th2 dominance of T helper cell response to preproinsulin in individuals with preclinical type 1 diabetes.

In human type 1 diabetes (T1D) autoantibodies to insulin precede clinical disease, while little is known about the contribution of insulin-specific T lymphocytes-in particular, T helper (Th) subsets. Here we have studied the in vivo primed cytokine response to preproinsulin in peripheral blood mononuclear cells (PBMCs) and two major Th cell subsets-CD45RO+ memory cells and CD45RA+ naive/resting cells-in 35 individuals with HLA-DRB1*04, DQB1*0302 diabetes risk marker: 12 patients with T1D, 12 autoantibody-positive (Ab+) individuals, and 11 healthy controls. Cytokine secretion (TNF-alpha, IFN-gamma, IL-2, IL-4, IL-5, and IL-10) was measured in the supernatants of the cultures stimulated with 21 overlapping preproinsulin peptides as well as proinsulin and insulin.

Human alpha-defensins HNPs-1, -2, and -3 in renal cell carcinoma: influences on tumor cell proliferation.

The alpha-defensins human neutrophil peptides (HNPs)-1, -2, and -3 have been described as cytotoxic peptides with restricted expression in neutrophils and in some lymphocytes. In this study we report that HNPs-1, -2, and -3 are also expressed in renal cell carcinomas (RCCs). Several RCC lines were found to express mRNA as well as the specific peptides of HNP-1, -2, and -3 demonstrated by reverse transcriptase-polymerase chain reaction, mass spectrometric, and flow cytometric analyses.