Photoreceptor proteins as cancer-retina antigens

Melanocytes, melanoma and photoreceptor cells are of neuroectodermal origin and have a certain sensitivity to light. In this study, we present evidence for photoreceptor proteins that are responsible for visual transduction and its regulation function as a new class of cancer antigens in melanoma. Visual rhodopsin, transducin, cGMP-phosphodiesterase 6, cGMP-dependent channels, guanylyl cyclase, rhodopsin kinase, recoverin and arrestin are expressed in melanoma and can induce antibody responses in patients. Melanocytes also express mRNA of all photoreceptor genes besides transducin, but were devoid of the corresponding protein, which was tested for rhodopsin, cGMP-phosphodiesterase, guanylyl cyclase and recoverin. Furthermore, we show for the first time that some healthy tissues express mRNA of these genes, but never protein. Expression profiles and autoantibody responses were confirmed in the MT/ret and the HGF(tg)/Ink4a(-/-) transgenic mouse melanoma models. We propose a molecular transition of cancer-retina antigens from mRNA expression in melanocytes to protein expression in melanoma. Our work provides the basis for analyzing regulation of photoreceptor gene expression in normal and malignant cells as well as possible therapeutic tumor targeting using the newly defined class of cancer-retina antigens.     

Primitive and committed human hematopoietic progenitor cells interact with primary murine neural cells and are induced to undergo self-renewing cell divisions

OBJECTIVE: Studies in animal models have indicated that hematopoietic progenitor cells (HPC) migrate and home to the central nervous system and might acquire neural features under specific circumstances. The interaction between HPC and the neural environment and the functional effect on hematopoiesis have not yet been defined. METHODS: CD34(+)133(+) cells from mobilized peripheral blood were cocultured with primary murine neurons or astrocytes. Chemotaxis and adhesive interactions were studied by applying beta(1)- and beta(2)-integrin function-blocking anibodies. The impact of neural feeder layers on integrin expression of HPC and the presence of appropriate adhesion ligands on neural cells were determined by immunostaining and flow cytometry. The hematopoietic long-term fate was monitored by time-lapse microscopy of individual cell-division history followed by long-term culture-initiating cell (LTC-IC) and colony-forming cell (CFC) assays. Neural differentiation was assessed by immunostaining against specific neuronal and glial antigens. RESULTS: The 23.0% +/- 4.9% of HPC showed stromal cell-derived factor-1-induced migration toward neural cells, and 20.2% +/- 1.6% displayed firm beta(1)-integrin-mediated adhesion to astrocytes. The latter expressed appropriate adhesion ligands, stabilized beta(1)-integrin expression, and increased beta(2)-integrin expression of HPC. Neural differentiation of HPC could not be identified but astrocytes were able to induce limited self-renewing cell divisions of HPC and thus maintain 25.8% +/- 3.4% of the initial LTC-IC and 80.7% +/- 1.9% of the initial CFC. CONCLUSION: Human HPC are able to interact with neural cells and interaction maintains, albeit to a limited extent, the self-renewal capability of HPC.     

Haemangioma of the Parathyroid Gland. Does it Really Exist?

We are reporting a case of a capillary haemangioma-like proliferation arising within a parathyroid gland adenoma, associated with primary hyperparathyroidism. The vessel proliferation bearing a close resemblance to a capillary haemangioma consisted of tightly packed capillaries, endothelial buds and occasional small caliber muscle-containing vessels. The observation expands the spectrum of tumour-associated vascular proliferations by adding an exuberant haemangioma-like pattern to its extreme end. These are a heterogeneous group of lesions reportedly induced by aberrant production of angiogenic factors. We investigated expression of VEGF, pKDR, FGF2, HIF1α and HIF2α and only VEGF gave a strong positive reaction in the adenoma cells entrapped in the vascular meshwork. Although this does not constitute a proof that aberrant VEGF production was a causative agent, unexpected supportive evidence for its pathogenic role emerged from a failure to detect chromogranin A. Chromogranin A is a precursor of several regulatory proteins, including vasostatin I, a multilevel suppressor of VEGF. The production of vasostatin I may have been reduced in a chromogranin A-negative adenoma which could lead to a loss of its opposing effect on VEGF–regulated processes. The only two other published cases of haemangioma of the parathyroid gland were reported in patients diagnosed with primary parathyroid hyperplasia with hyperparathyroidism, a pathophysiologic condition similar to our case. Therefore we raise the question whether these tumours could also represent a reactive phenomenon.     

CHEK2 1100delC mutation is frequent among Russian breast cancer patients

This study was aimed to assess the role of CHEK2 1100delC mutation in breast cancer (BC) predisposition in Russia. The 1100delC allele was detected in 14/660 (2.1%) unilateral BC cases and in 8/155 (5.2%) patients with the bilateral form of the disease, but only in 1/448 (0.2%) middle-aged control females and in none of 373 elderly tumor-free women. The obtained data point at potentially high clinical relevance of CHEK2 1100delC testing in females of Russian origin and warrant similar case-control studies in ethnically and geographically related regions, especially in Ukraine, Belarus and Baltic countries.     

Application of constant-current coulometry for estimation of plasma total antioxidant capacity and its relationship with transition metal contents

Simple and express coulometric method for the evaluation of the total antioxidant capacity (TAC) of human plasma based on the reaction with electrogenerated bromine is applied. TAC of plasma from patients with different ethiology of chronic renal failure was observed. The levels of antioxidant capacity for venous and arterial plasma are authentically different (15+/-1 kCl/L versus 11.7+/-0.7 kCl/L, p<0.01). The application of Vitamin E and ximedon as an antioxidant treatment significantly increase TAC level of plasma. Free liposoluble antioxidants in plasma in alpha-tocopherol units was determined. Redox potential of plasma is measured and its correlation with lg(TAC) is obtained. Transition metal contents of Fe, Cu, Mn, Ni, and Cr in plasma of patients with chronic renal failure is significantly higher than that for a control group. Correlation analysis has shown negative linear regression between TAC value and transition metals concentration in plasma. This confirms interrelation of processes with participation of free radicals, antioxidants and transition metals as donors of electrons in chain radical processes. Moreover, it shows utility of common parameters, TAC for example, for estimation of efficiency of antioxidant defense system in living organism, in particular its antioxidant status.     

NBS1 657del5 mutation may contribute only to a limited fraction of breast cancer cases in Russia

The gene for Nijmegen chromosomal breakage syndrome (NBS1) plays a role in a variety of processes protecting chromosomal stability. Recently, it was suggested in a Polish case-control study that the founder hypomorphic mutation in NBS1, 657del5, which occurs in approximately 0.5% of Slavic subjects, may be associated with an increased risk of breast cancer (BC). We attempted to validate these findings in Russian subjects, who are also of Slavic descent. Heterozygous carriers for the 657del5 mutation were detected in 2 of 173 (1.16%) bilateral breast cancer cases, 5 of 700 (0.71%) unilateral breast cancer patients, 2 of 348 (0.57%) healthy middle-aged females and in 0 of 344 elderly tumor-free women. The difference between the "extreme" cohorts, i.e., biBC patients vs. elderly controls, approached the formal limit of statistic significance (p=0.046). LOH at NBS1 was detected in only 3 of 5 available breast tumors from NBS1 657del5-carriers. In 2 of these tumors, the loss involved the mutant NBS1-allele. Overall, our data suggest that the NBS1 657del5 allele may contribute only to a limited fraction of breast cancer cases in Russia.     

US features of the normal appendix and surrounding area in children

PURPOSE: To evaluate prospectively the frequency of depiction with ultrasonography (US) of the appendix in children without clinical suspicion of acute appendicitis and to evaluate the US appearance of the normal appendix. MATERIALS AND METHODS: Between March 2003 and July 2003, 146 consecutive patients (62 boys and 84 girls; mean age, 7 years; age range, 2-15 years) without clinical suspicion of acute appendicitis were examined with US. Patients with cystic fibrosis and those with acute abdominal pain were excluded from the study. Outer diameters, mural thickness, and color Doppler flow were measured. Appendiceal lumen and surroundings of the appendix were determined. The overall diameter and mural thickness of the appendix were examined for relationship to age, weight, or height of the patient. For statistical analysis, the Mann-Whitney test, Student t test, and linear regression analysis were applied. RESULTS: In 120 (82%) children, the appendix was depicted with US; in 26 (18%) children, this was not possible. In 114 (95%) of the depicted appendices, the position was classical; we observed six (5%) retrocecal appendices. All appendices were compressible. Mean diameter of the appendix was 0.39 cm (range, 0.21-0.64 cm), and the mean mural thickness was 0.18 cm (range, 0.11-0.27 cm). The appendiceal lumen was empty in 74 (62%) children. The others were filled with fecal material, gas, or both. In 75 (51%) of the 146 children, lymph nodes were present in the right lower quadrant of the abdomen. We found no relation between the age, weight, or height of the examined child and the overall diameter or wall of the appendix. CONCLUSION: The results of this study show that a normal appendix can be depicted with US in 82% of asymptomatic children.     

Enhancement effects of (R) and (S) enantiomers and the racemate of a model enhancer on permeation of theophylline through human skin

The conformation of a permeation enhancer, given their mechanism of action, could influence its enhancing properties, since the stratum corneum components form essentially a chiral environment. The racemate and both enantiomers of 6-aminohexanoic acid 2-octylester as model enhancers with one chiral center were synthesized and their ability to enhance in vitro theophylline permeation through human skin was tested. The MTMT concept could not be applied in this study (the melting points of the substances were lower than 20 masculine C) and we observed no significant difference in enhancement ratios (ERs) of racemic 6-aminohexanoic acid 2-octylester and that of each enantiomer. However, differences in permeation rates between enantiomers and their racemates do not have to be related to stereoselective interactions, since they may also be explained by differences in physicochemical properties. The study also showed that there was no difference in the permeation enhancement ability between the (R)-(-) and (S)-(+) isomers of 6-aminohexanoic acid 2-octylester (the ERs were 2.72+/-0.42 and 2.79+/-0.60 for (R) and (S) enantiomers, respectively), suggesting that the enhancing properties of the compounds are not dependent on their spatial arrangement. Although stereoselective interactions between an enhancer and stratum corneum components may exist, they seem not to be important for the enhancer action.     

Antirecoverin autoantibodies in the patient with non-small cell lung cancer but without cancer-associated retinopathy

The goal of the present study was to analyze serum and tumor tissue of a patient with non-small cell lung cancer (NSCLC) for the presence of autoantibodies against recoverin (anti-Rc) and recoverin expression, correspondingly. Using immunoblotting with recombinant recoverin as an antigen, we have detected anti-Rc in serum of the patient. At the same time, the patient did not manifest any signs of cancer-associated retinopathy (CAR). Polyclonal (monospecific) antibodies against recoverin used for immunohistochemical analysis of the patient's tumor revealed recoverin expression in the tumor sections. To our knowledge, this is the first case of the presence of serum anti-Rc in NSCLC patients in the absence of paraneoplastic retina degeneration.     

SYD-1, a presynaptic protein with PDZ,C2 and rhoGAP-like domains,specifies axon identity in C. elegans

Axons are defined by the presence of presynaptic specializations at specific locations. We show here that loss-of-function mutations in the C. elegans gene syd-1 cause presynaptic specializations to form in the dendritic processes of GABA-expressing motor neurons during initial differentiation. At a later developmental stage, however, syd-1 is not required for the polarity respecification of a subset of these neurons. The SYD-1 protein contains PDZ, C2 and rho-GTPase activating protein (GAP)-like domains, and is localized to presynaptic terminals in mature neurons. A truncated SYD-1 that lacks the rhoGAP domain interferes with neurite outgrowth and guidance. Our data indicate that syd-1 may be involved in specifying axon identity during initial polarity acquisition.