The expression pattern of MUC1 (EMA) is related to tumour characteristics and clinical outcome of invasive ductal breast carcinoma

Aims: To clarify MUC1 patterns in invasive ductal breast carcinoma and to relate them to clinicopathological parameters, coexpression of other biological markers and prognosis. Methods and results: Samples from 243 consecutive patients with primary ductal carcinoma were incorporated into tissue microarrays (TMAs). Slides were stained for MUC1, oestrogen receptor (ER), progesterone receptor (PR), Her2/neu, p53 and cyclin D1. Apical membrane MUC1 expression was associated with smaller tumours (P = 0.001), lower tumour grades (P < 0.001), PR positivity (P = 0.003) and increased overall survival (OS; P = 0.030). Diffuse cytoplasmic MUC1 expression was associated with cyclin D1 positivity (P = 0.009) and increased relapse-free survival (RFS; P = 0.034). Negativity for MUC1 was associated with ER negativity (P = 0.004), PR negativity (P = 0.001) and cyclin D1 negativity (P = 0.009). In stepwise multivariate analysis MUC1 negativity was an independent predictor of both RFS [hazard ratio (HR) 3.5, 95% confidence interval (CI) 1.5, 8.5; P = 0.005] and OS (HR 14.7, 9 5% Cl 4.9, 44. 1; P < 0.001). Conclusions: The expression pattern of MUC1 in invasive ductal breast carcinoma is related to tumour characteristics and clinical outcome. In addition, negative MUC1 expression is an independent risk factor for poor RFS and OS, besides 'classical' prognostic indicators

Glycosylation pattern of brush border-associated glycoproteins in enterocyte-like cells: involvement of complex-type N-glycans in apical trafficking

We have previously reported that galectin-4, a tandem repeat-type galectin, regulates the raft-dependent delivery of glycoproteins to the apical brush border membrane of enterocyte-like HT-29 cells. N-Acetyllactosamine-containing glycans, known as galectin ligands, were found enriched in detergent-resistant membranes. Here, we analyzed the potential contribution of N-and/ or O-glycans in this mechanism. Structural studies were carried out on the brush border membrane-enriched fraction using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and nano-ESI-QTOF-MS/MS. The pattern of N-glycans was very heterogeneous, with the presence of high mannose- and hybrid-type glycans as well as a multitude of complex-type glycans. In contrast, the pattern of O-glycans was very simple with the presence of two major core type 1 O-glycans, sialylated and bisialylated T-antigen structures {[}Neu5Ac alpha 2-3Gal beta 1-3GalNAc-ol and Neu5Ac alpha 2-3Gal beta 1 -3(Neu5Ac alpha 2-6)GalNAc-ol]. Thus, N-glycans rather than O-glycans contain the N-acetyllactosamine recognition signals for the lipid raft-based galectin-4-dependent apical delivery. In the presence of 1-deoxymannojirimycin, a drug which inhibits the generation of hybrid-type or complex type N-glycans, the extensively O-glycosylated mucin-like MUC1 glycoprotein was not delivered to the apical brush border but accumulated inside the cells. Altogether, our data demonstrate the crucial role of complex N-glycans in the galectin-4-dependent delivery of glycoproteins to the apical brush border membrane of enterocytic HT-29 cells

Tissue-specific expression of a human Polymorphic Epithelial mucin (MUCI) in transgenic mice

The human MUC1 gene codes for the core protein of a mucin which is expressed by glandular epithelia and the carcinomas which develop from these tissues. The core protein is aberrantly glycosylated in cancers, and some antibodies show specificity in their reactions with the cancer-associated mucin, which also contains epitopes recognized by T-cells from breast and pancreatic cancer patients. For evaluating the potential use of mucin-reactive antibodies and mucin-based immunogens in cancer patients, a mouse model, expressing the MUC1 gene product PEM (polymorphic epithelial mucin) as a self antigen, would be extremely useful. To this end, we have developed transgenic mouse strains expressing the human MUC1 gene product in a tissue-specific manner. The TG4 mouse strain was established using a 40-kilobase fragment containing 4.5 kilobases of 5\u27 and 27 kilobases of 3\u27 flanking sequence. The TG18 strain was developed using a 10.6-kilobase SacII fragment from the 40-kilobase fragment; this fragment contained 1.6 kilobases of 5\u27 sequence and 1.9 kilobases of 3\u27 flanking sequence. Both strains showed tissue specificity of expression of the MUC1 gene, which was very similar to the profile of expression seen in human tissues. The antibody SM-3 is directed to a core protein epitope, which is selectively exposed in breast cancers and which shows a more restricted distribution on normal human tissues. It was established that the distribution of the SM-3 epitope of PEM in the tissues of the transgenic mice is similar to that seen in humans. The transgenic mouse strains described here should form the basis for the development of a preclinical model for the evaluation of PEM-based antigens and of antibodies directed to PEM in cancer therapy

The MUC1 Cytoplasmic Tail and Tandem Repeat Domains Contribute to Mammary Oncogenesis in FVB Mice

Background: Though the importance of the transmembrane mucin MUC1 in mammary oncogenesis has long been recognized, the relative contributions of the cytoplasmic tail and tandem repeat domains are poorly understood.Methods: To address this, mouse models of mammary carcinogenesis were created expressing full-length, cytoplasmic tail-deleted, or tandem repeat-deleted MUC1 constructs.Results: Overexpression of full-length MUC1 resulted in tumor formation in young mice (12 months); however, loss of either the cytoplasmic tail or the tandem repeat domain abrogated this oncogenic capacity. Aged mice in all strains developed late-onset mammary tumors similar to those previously described for the FVB background.Conclusions: This study is the fi rst spontaneous cancer model to address the relative importance of the cytoplasmic tail and tandem repeat domains to MUC1-driven mammary oncogenesis, and suggests that both of these domains are essential for tumor formation

Genetic regulation of MUC1 alternative splicing in human tissues

The membrane mucin MUC1 is aberrantly expressed in a variety of cancers, and in stomach, it is a ligand for Helicobacter pylori where it plays a role in gastric carcinogenesis. Splicing variation, leading to a 9-amino acid insertion in the signal peptide region, was proposed to be because of a single-nucleotide polymorphism (rs4072037) at the 5′ end of exon 2, but is also reported to be cancer-associated. However, the effect of rs4072037 on this splicing event in healthy non-cancer tissues and on the additional spliceoforms of MUC1, including those lacking the polymorphic tandem repeat (TR) domain, has never been investigated. Here we show that in both foetal and adult tissues of known genotype, there is clear evidence for the role of rs4072037 in controlling alternative splicing of the 5′ exon 2 region of both full-length transcripts and those lacking the TR domain. Although there is some evidence for additional genetic and epigenetic influences, there is no indication of an effect of the TR domain on the proportions of the spliceoforms. In conclusion, over-representation of certain transcripts in tumour material cannot be evaluated without information on the SNP genotype as well

Gedanken experiments with Casimir forces, vacuum energy, and gravity

Gedanken experiments are used to explore properties of quantum vacuum energy that are currently challenging to explore experimentally. A constant lateral Casimir force is predicted to exist between two overlapping finite parallel plates at 0 K, otherwise it would be possible to extract an arbitrary amount of energy from the quantum vacuum. A rigid unpowered object cannot be accelerated by the quantum vacuum because of the translational symmetry of space. By considering systems in which vacuum energy and other forms of energy are exchanged, we demonstrate that a change {\Delta}E in vacuum energy, whether positive or negative with respect to the free field, corresponds to an equivalent inertial mass and equivalent gravitational mass {\Delta}M={\Delta}E/c^2. We consider the possibility of a gravitational shield, and show that, if it exists, the energy to operate it would have to cancel the net energy extracted from the gravitational field, otherwise we could extract an arbitrary amount of energy from the field.Comment: 24 pages, 3 figure

Imagination and Film

This chapter addresses the application of contemporary theories of the imagination—largely drawn from cognitive psychology—to our understanding of film. Topics include the role of the imagination in our learning what facts hold within a fictional film, including what characters’ motivations, beliefs, and feelings are; how our perceptual experience of a film explains our imaginative visualizing of its contents; how fictional scenarios in films generate certain affective and evaluative responses; and how such responses compare to those we have toward analogous circumstances in real life

Glycocalyx Restricts Adenoviral Vector Access to Apical Receptors Expressed on Respiratory Epithelium In Vitro and In Vivo: Role for Tethered Mucins as Barriers to Lumenal Infection

Inefficient adenoviral vector (AdV)-mediated gene transfer to the ciliated respiratory epithelium has hindered gene transfer strategies for the treatment of cystic fibrosis lung disease. In part, the inefficiency is due to an absence of the coxsackie B and adenovirus type 2 and 5 receptor (CAR) from the apical membranes of polarized epithelia. In this study, using an in vitro model of human ciliated airway epithelium, we show that providing a glycosylphosphatidylinositol (GPI)-linked AdV receptor (GPI-CAR) at the apical surface did not significantly improve AdV gene transfer efficiency because the lumenal surface glycocalyx limited the access of AdV to apical GPI-CAR. The highly glycosylated tethered mucins were considered to be significant glycocalyx components that restricted AdV access because proteolytic digestion and inhibitors of O-linked glycosylation enhanced AdV gene transfer. To determine whether these in vitro observations are relevant to the in vivo situation, we generated transgenic mice expressing GPI-CAR at the surface of the airway epithelium, crossbred these mice with mice that were genetically devoid of tethered mucin type 1 (Muc1), and tested the efficiency of gene transfer to murine airways expressing apical GPI-human CAR (GPI-hCAR) in the presence and absence of Muc1. We determined that AdV gene transfer to the murine airway epithelium was inefficient even in GPI-hCAR transgenic mice but that the gene transfer efficiency improved in the absence of Muc1. However, the inability to achieve a high gene transfer efficiency, even in mice with a deletion of Muc1, suggested that other glycocalyx components, possibly other tethered mucin types, also provide a significant barrier to AdV interacting with the airway lumenal surface