lewis-y-antigen and Carcinoma

Topics: Animals; Antibiotics, Antineoplastic; Antibodies, Monoclonal; Antigens, Neoplasm; Carcinoma; Clinical Trials, Phase I as Topic; Colonic Neoplasms; Daunorubicin; Digestive System; Doxorubicin; Drug Design; Gastrointestinal Diseases; Humans; Immunotoxins; Lewis Blood Group Antigens; Mice; Mice, Nude; Neoplasms; Neoplasms, Experimental; Organ Specificity; Rats; Rats, Inbred BN; Rats, Nude; Treatment Failure; Xenograft Model Antitumor Assays

Lewis y (LeY) antigen is a difucosylated oligosaccharide carried by glycoconjugates on the cell surface. Overexpression of LeY is frequently observed in epithelial-derived cancers and has been correlated to the pathological staging and prognosis. However, the effects of LeY on ovarian cancer are not yet clear. Previously, we transfected the ovarian cancer cell line RMG-I with the α1,2-fucosyltransferase gene to obtain stable transfectants, RMG-I-H, that highly express LeY. In the present study, we examined the proliferation, tumorigenesis, adhesion and invasion of the cell lines with treatment of LeY monoclonal antibody (mAb). Additionally, we examined the expression of TGF-β1, VEGF and b-FGF in xenograft tumors. The results showed that the proliferation and adhesion in vitro were significantly inhibited by treatment of RMG-I-H cells with LeY mAb. When subcutaneously inoculated in nude mice, RMG-I-H cells produced large tumors, while mock-transfected cells RMG-I-C and the parental cells RMG-I produced small tumors. Moreover, the tumor formation by RMG-I-H cells was inhibited by preincubating the cells with LeY mAb. Notably, the expression of TGF-β1, VEGF and b-FGF all increased in RMG-I-H cells. In conclusion, LeY plays an important role in promoting cell proliferation, tumorigenecity and adhesion, and these effects may be related to increased levels of growth factors. The LeY antibody shows potential application in the treatment of LeY-positive tumors.

Topics: Animals; Carcinogenesis; Carcinoma; Cell Adhesion; Cell Line, Tumor; Cell Proliferation; Female; Fibroblast Growth Factors; Humans; Lewis Blood Group Antigens; Mice; Mice, Nude; Ovarian Neoplasms; Transforming Growth Factor beta; Up-Regulation; Vascular Endothelial Growth Factor A

Linking a cytotoxic anticancer drug to an antibody that recognizes a tumor-associated antigen can improve the therapeutic index of the drug. We asked whether a conjugate of the cytotoxic antibiotic N-acetyl gamma calicheamicin dimethyl hydrazide (CalichDMH) and an antibody recognizing Lewis(y) (Le(y)) antigen could eliminate carcinomas that express Le(y). Because Le(y) is highly expressed on carcinomas of colon, breast, lung, ovary, and prostate, a CalichDMH conjugate targeting Le(y) could provide a treatment option for various cancers.. The humanized anti-Le(y) antibody hu3S193 was conjugated to CalichDMH via the bifunctional AcBut linker. Selectivity and avidity of the conjugate (hu3S193-CalichDMH) for Le(y)-BSA or Le(y+) cells was tested by BIAcore or flow cytometry. Cytotoxicity of hu3S193-CalichDMH was compared with toxicity of a control conjugate on monolayers of Le(y+) and Le(y-) carcinoma cells. Inhibition of tumor growth by hu3S193-CalichDMH was assessed on three types of s.c. xenografts.. Hu3S193-CalichDMH had similar selectivity as hu3S193. The conjugate had lower affinity for Le(y)-BSA but not for Le(y+) cells. When tested on monolayers of human Le(y+) carcinoma cells, hu3S193-CalichDMH was more cytotoxic than a control conjugate. This difference in efficacy was not noted on Le(y-) cells. Efficacy of hu3S193-CalichDMH depended on the expression of Le(y) and on the sensitivity of the cells to CalichDMH. In vivo, hu3S193-CalichDMH inhibited growth of xenografted human gastric (N87), colon (LOVO), and prostate carcinomas (LNCaP). When used against N87 xenografts, hu3S193-CalichDMH arrested tumor growth for at least 100 days.. Hu3S193-CalichDMH can specifically eliminate Le(y+) tumors. These results support development of this conjugate for treatment of carcinomas.

Topics: Aminoglycosides; Animals; Antibodies, Monoclonal; Antigens; Carcinoma; Cell Line, Tumor; Cell Separation; Collagen; Dose-Response Relationship, Drug; Dose-Response Relationship, Immunologic; Drug Combinations; Enediynes; Female; Flow Cytometry; Humans; Hydrazines; Hydrolysis; Immunotherapy; Kinetics; Laminin; Lewis Blood Group Antigens; Male; Mice; Mice, Nude; Models, Chemical; Neoplasm Transplantation; Protein Binding; Proteoglycans; Sensitivity and Specificity; Surface Plasmon Resonance; Tissue Distribution

A single-chain antibody fragment (scFv) of the humanised monoclonal antibody, hu3S193, that reacts specifically with Le(y) antigen expressed in numerous human epithelial carcinomas was constructed. A five-residue linker joined the C-terminus of the V(H) and the N-terminus of the V(L), which prevented V-domain association into a monomeric scFv and instead directed non-covalent association of two scFvs into a dimer or diabody. The diabody was secreted into the E. coli periplasm using a heat-inducible vector, pPOW3, and recovered as a soluble, correctly processed protein, following osmotic shock or solubilised with 4 M urea from the insoluble fraction. The diabody from both fractions was isolated by a rapid batch affinity chromatography procedure, using the FLAG affinity tag to minimise degradation and aggregation. The purified diabody has an Mr of approximately 54 kDa, was stable and demonstrated similar binding activity as the parent monoclonal antibody, as measured by FACS and BIAcore analyses. The radiolabelled diabody showed a rapid tumour uptake, with fast blood clearance, proving it to be an excellent potential candidate as a tumour-imaging agent.

Topics: Amino Acid Sequence; Animals; Antibodies, Monoclonal; Antigens, Neoplasm; Biosensing Techniques; Carcinoma; Escherichia coli; Flow Cytometry; Genetic Vectors; Hot Temperature; Humans; Immunoglobulin Variable Region; Kinetics; Lewis Blood Group Antigens; Mice; Mice, Inbred BALB C; Mice, Nude; Molecular Sequence Data; Tumor Cells, Cultured

The object of this study was the investigation of carbohydrate antigen expression in malignant epithelial cells and benign mesothelial cells in serous effusions from patients diagnosed with epithelial ovarian carcinomas. In addition, to compare antigen expression in carcinoma cells in effusions with those of corresponding primary tumors and metastatic lesions. Sections from 63 malignant effusions from ovarian carcinoma patients and 15 reactive effusions were immunohistochemically stained, using 5 monoclonal antibodies for Lewis(y), Sialyl Lewis(x), Tn, and Sialyl Tn antigens. Tissue sections (n = 97) from corresponding primary ovarian carcinomas and metastatic lesions, as well as from 12 malignant mesotheliomas, were additionally stained using the above panel. Staining for the 4 antigens was seen in carcinoma cells in serous effusions in the majority of cases (range = 71% to 85%). In contrast, immunoreactivity was detected in mesothelial cells in only 6% to 23% of the specimens studied (P < .001 for all 5 markers). With the exception of B3 antibody against Lewis(y) antigen, malignant mesotheliomas stained negative, infrequently showing focal immunoreactivity. An up-regulation of Tn and Sialyl Tn expression was detected in carcinoma cells in effusions when compared with both primary tumors (P < .003 and P < .007, respectively) and metastatic lesions (P < .034 and .041, respectively). Cancer-associated carbohydrate antigens can thus be used as an adjunct in the differentiation between malignant epithelial and reactive mesothelial cells. Ovarian carcinoma cells in effusions show up-regulation of Tn and Sialyl Tn, possibly representing a transient phenotypic alteration facilitating metastasis.

Topics: Antigens, Tumor-Associated, Carbohydrate; Ascitic Fluid; Biomarkers, Tumor; Carcinoma; Exudates and Transudates; Female; Humans; Immunoenzyme Techniques; Lewis Blood Group Antigens; Mesothelioma; Neoplasms, Mesothelial; Ovarian Neoplasms; Pleural Effusion, Malignant; Up-Regulation

LMB-1 (B3-LysPE38) is an immunotoxin composed of the tumor-reactive monoclonal antibody B3 and a genetically engineered form of Pseudomonas exotoxin. Monoclonal antibody B3 reacts with a carbohydrate epitope that is found on a number of solid tumors (e.g., breast, ovarian, and lung carcinomas) that frequently invade the intrathecal space, causing neoplastic meningitis. The Pseudomonas exotoxin has been engineered to remove the binding domain to eliminate nonspecific binding. A model of human neoplastic meningitis using rats bearing the human epidermoid carcinoma A431 was used for therapeutic studies of immunotoxin LMB-1. Therapy was initiated 3 days after injection of the tumor cells, which was one third of the median survival time of untreated rats. A single intrathecal injection of 40 microgram increased median survival from 9 days with saline injection to 16 days (78%, P < 0.001), and a single dose of 200 microgram increased median survival to 25 days (188%, P < 0. 001). Three doses of 40 or 200 microgram given on days 3, 6, and 8 significantly increased the median survival of 9.5 days associated with saline injection to 40.5 days (326% increase) and 33.0 days (247% increase), respectively, with two long-term survivors (191-day survival) in each treatment group. LMB-1 had no therapeutic effect on the treatment of two B3 antigen-negative neoplastic meningitis models. Treatment of the antigen-positive A431 neoplastic meningitis with B3 alone or a nonspecific monoclonal, MOPC, coupled to the engineered Pseudomonas exotoxin produced no survival effects. Nontumor-bearing athymic rats showed no toxicity with a single dose of either 40 microgram or 200 microgram, or 3 doses of 40 microgram. However, when they were given three doses of 200 microgram, these rats showed weight loss and loss of neurological function, and two of eight animals died. These studies indicate that, in the range of the most therapeutically effective dosage, the immunotoxin LMB-1 is tolerated in the intrathecal space and should be considered for human intrathecal trials.

Topics: ADP Ribose Transferases; Animals; Antibodies, Monoclonal; Bacterial Toxins; Carcinoma; Disease Models, Animal; Drug Screening Assays, Antitumor; Exotoxins; Humans; Immunotoxins; Lewis Blood Group Antigens; Meningeal Neoplasms; Pseudomonas aeruginosa Exotoxin A; Rats; Rats, Nude; Tumor Cells, Cultured; Virulence Factors