cefoxitin and Skin-Neoplasms

Cutaneous melanoma, the most aggressive form of skin cancer, responds poorly to conventional therapy. The appearance of Tn antigen-modified proteins in cancer is correlated with metastasis and poor prognoses. The Tn determinant has been recognized as a powerful diagnostic and therapeutic target, and as an object for the development of anti-tumor vaccine strategies. This study was designed to identify Tn-carrying proteins and reveal their influence on cutaneous melanoma progression. We used a lectin-based strategy to purify Tn antigen-enriched cellular glycoproteome, the LC-MS/MS method to identify isolated glycoproteins, and the DAVID bioinformatics tool to classify the identified proteins. We identified 146 different Tn-bearing glycoproteins, 88% of which are new. The Tn-glycoproteome was generally enriched in proteins involved in the control of ribosome biogenesis, CDR-mediated mRNA stabilization, cell-cell adhesion and extracellular vesicle formation. The differential expression patterns of Tn-modified proteins for cutaneous primary and metastatic melanoma cells supported nonmetastatic and metastatic cell phenotypes, respectively. To our knowledge, this study is the first large-scale proteomic analysis of Tn-bearing proteins in human melanoma cells. The identified Tn-modified proteins are related to the biological and molecular nature of cutaneous melanoma and may be valuable biomarkers and therapeutic targets.

Topics: Antigens, Tumor-Associated, Carbohydrate; Biomarkers, Tumor; Cell Line, Tumor; Chromatography, Liquid; Glycoproteins; Humans; Melanoma; Neoplasm Metastasis; Proteomics; Skin Neoplasms; Tandem Mass Spectrometry

Nucleolin is multifunctional protein mainly present in nucleoli but also detected in cytoplasm and plasma membranes. Extranuclear nucleolin differs from the nuclear form by its glycosylation. Studies on expression of nucleolin in breast cancer suggest a possible association to the metastatic cascade. In the present study, Vicia villosa lectin (VVL) precipitation followed by subsequent polyacrylamide gel electrophoresis and mass spectrometry analysis demonstrates nucleolin as a VVL-positive glycoprotein expressed in melanoma. The presence of VVL-positive nucleolin in the melanoma cell membrane and cytoplasm was confirmed by confocal microscopy. Using bioinformatic peptide prediction programs, nucleolin was shown to contain multiple possible MHC class-I binding peptides in its sequence which makes nucleolin an interesting melanoma marker and target for immunodiagnostic and possibly therapeutic purposes.

Topics: Amino Acid Sequence; Antigens, Tumor-Associated, Carbohydrate; Blotting, Western; Cell Membrane; Cell Nucleolus; Computational Biology; Cytoplasm; Fluorescent Antibody Technique; Genes, MHC Class I; Glycoproteins; Humans; Immunoblotting; Immunoenzyme Techniques; Mass Spectrometry; Melanoma; Molecular Sequence Data; Nucleolin; Phosphoproteins; Plant Lectins; RNA-Binding Proteins; Skin Neoplasms; Tumor Cells, Cultured

To study the immunohistochemical expression of the Thomsen-Friedenreich antigen (T) and its precursor, Tn, in the skin in various cancers.. T and Tn antigens were studied with monoclonal antibodies in 91 primary premalignant and malignant lesions, 13 cases of Paget's disease, and 26 carcinomas metastatic to the skin. The material had been collected over a 10 year period, formalin fixed, and paraffin embedded. Diagnoses had been made after examination of standard histological sections, supplemented when needed by appropriate immunohistochemical staining.. 21% and 29% of the primary cutaneous premalignant and malignant epithelial tumours expressed the Tn and T antigens, respectively. By contrast, 81% of metastatic carcinomas to the skin were Tn positive, while only 23% of them expressed the T antigen. All cases of Paget's disease were Tn positive but only 15% of them expressed the T antigen. The 21 nonepithelial tumours (including melanomas) were as a rule unreactive.. The accumulation of the precursor (Tn) antigen in tumours metastasising to the skin highlights the incomplete glycosylation of carbohydrate antigens occurring in these tumours. The predominant Tn versus T antigen expression appears to be a useful immunohistochemical feature which may aid in the differentiation of primary cutaneous carcinomas from metastatic tumours.

Topics: Antigens, Neoplasm; Antigens, Tumor-Associated, Carbohydrate; Biomarkers, Tumor; Female; Humans; Immunoenzyme Techniques; Paget Disease, Extramammary; Paget's Disease, Mammary; Precancerous Conditions; Skin Neoplasms