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ABSTRACT: The selection and characterization of a set of mouse mAbs against high-risk human papillomavirus (HPV) E7 oncoprotein and the development of protocols for immunocytochemistry (ICC) are described here. A large number of antibodies raised towards HPV16 and 18 E7 were tested for high-risk specificity by ELISA using a panel of HPV E7 proteins. Antibodies detecting low-risk E7 were discarded, resulting in 38 high-risk HPV E7-specific antibodies. The corresponding epitopes were mapped using overlapping HPV E7 fragments displayed on phage particles. Functionality in ICC against formalin-fixed cervical cancer cell lines was demonstrated for ten mAbs; their high-risk specificity was confirmed by Western blot analysis and ICC on transiently transformed cells expressing high- or low-risk HPV E7. These mAbs were specific for one or several of the high-risk strains HPV16, 18, 31, 35 and 45. Specific E7 staining of liquid-based cytology (LBC) samples was demonstrated for seven mAbs and optimized protocols were established. The E716-41 and E718-79 mAbs demonstrated particularly strong and specific staining of cells stored in LBC fluid for at least 6 months. It is proposed that the high-risk HPV E7 staining protocols established in this study may have the potential to be included in a complementary test for the detection and identification of malignantly transformed cells, in for example atypical squamous cells of undetermined significance samples.
Journal of General Virology 02/2012; 93(Pt 2):356-63. · 3.36 Impact Factor
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Elisabeth Paus,
Mads Haugland Haugen,
Kari Hauge Olsen,
Kjersti Flatmark,
Gunhild Mari Maelandsmo, Olle Nilsson,
Eva Röijer,
Maria Lundin,
Christian Fermér,
Maria Samsonova,
Yuri Lebedin,
Torgny Stigbrand
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ABSTRACT: Fourteen monoclonal antibodies with specificity against native or recombinant antigens within the S100 family were investigated with regard to immunoreactivity. The specificities of the antibodies were studied using ELISA tests, Western blotting epitope mapping using competitive assays, and QCM technology. The mimotopes of antibodies against S100A4 were determined by random peptide phage display libraries. Antibody specificity was also tested by IHC and pair combinations evaluated for construction of immunoradiometric assays for S100B. Out of the 14 antibodies included in this report eight demonstrated specificity to S100B, namely MAbs 4E3, 4D2, S23, S53, 6G1, S21, S36, and 8B10. This reactivity could be classified into four different epitope groups using competing studies. Several of these MAbs did display minor reactivity to other S100 proteins when they were presented in denatured form. Only one of the antibodies, MAb 3B10, displayed preferential reactivity to S100A1; however, it also showed partial cross-reactivity with S100A10 and S100A13. Three antibodies, MAbs 20.1, 22.3, and S195, were specific for recombinant S100A4 in solution. Western blot revealed that MAb 20.1 and 22.3 recognized linear epitopes of S100A4, while MAb S195 reacted with a conformational dependent epitope. Surprisingly, MAb 14B3 did not demonstrate any reactivity to the panel of antigens used in this study.
Tumor Biology 02/2011; 32(1):1-12. · 1.94 Impact Factor
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ABSTRACT: Detection of proteins that signal the presence or recurrence of cancer is a powerful therapeutic tool for effective early diagnosis and treatment. Carcinoembryonic antigen (CEA) has been extensively studied as a tumor marker in clinical diagnosis. We report on the development of an amperometric biosensor for the detection of CEA based on the immobilization of anti-CEA monoclonal antibody on a novel class of bipodal thiolated self-assembled monolayers containing reactive N-hydroxysuccinimide (NHS) ester end groups. The current variations showed a linear relationship with the concentration of CEA over the range of 0-200 ng/mL with a sensitivity of 3.8 nA x mL x ng(-1) and a detection limit of 0.2 ng/mL, which is well below the commonly accepted concentration threshold (5 ng/mL) used in clinical diagnosis. Real time and accelerated stability studies of the reporter antibody under various storage conditions demonstrated that the enzymatic activity and antibody affinity of the conjugate is retained for long periods of time in commercial stabilizing buffers such as StabilGuard Biomolecule Stabilizer, and a prediction of the stability trends was carried out using the kinetic and thermodynamic parameters obtained from the Arrhenius equation. The developed immunosensor as well as a commercially available enzyme-linked immunosorbent assay (ELISA) kit were successfully applied to the detection of CEA in serum samples obtained from colon cancer patients, and an excellent correlation of the levels of CEA measured was obtained. Ongoing work is looking at the incorporation of the developed biosensor into a platform for multiplexed simultaneous detection of several breast cancer related biomarkers.
Analytical Chemistry 03/2010; 82(5):1712-9. · 5.86 Impact Factor
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ABSTRACT: The paper describes a method to use filamentous phage to display specific regions of proteins for immunization in order to direct the immune response towards a pre-defined region of the protein. The method called site-specific immunization (SSI) was evaluated using the E7 protein of oncogenic (high-risk) human papillomavirus (HPV) type 16 as a model system. This protein consists of sequence blocks also present in other viral and cellular proteins and in the corresponding protein of low-risk HPVs. A fragment of the HPV16 E7 oncoprotein specific for a group of high-risk viruses was identified by sequence comparison and displayed on filamentous phages in fusion with the major phage coat protein VIII. The recombinant phages triggered an immune response in mice against the full-length HPV16 E7 protein. Fusion of B-lymphocytes from the immunized animals with myeloma cells resulted in three hybridomas producing monoclonal antibodies (MAbs) with reactivity against the endogenous E7 protein. The specificity of the MAbs for the HPV16 E7 protein in cancer cell lines was confirmed by Western blot analyses and immunocytochemistry. The epitope of each MAb was roughly mapped by determining the reactivity against overlapping E7 fragments displayed on phage particles. The mimotopes of the MAbs were further determined by biopanning against a randomized peptide library displayed on phage and found to be unique for a sub-set of high-risk HPV E7 proteins. The combination of different phage display techniques for immunization and epitope mapping was efficient for generation and characterization of highly specific MAbs.
Journal of Immunological Methods 08/2008; 337(2):88-96. · 2.20 Impact Factor
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ABSTRACT: Over the past 5 years, the on-chip detection and manipulation of magnetic beads via magnetoelectronics has emerged as a promising new biosensor platform. Magnetic bead sensing (MBS) provides a highly sensitive and specific technique, enabling these sensors to meet the diagnostic needs that are currently not met by existing technologies. Although many studies have proven the high physical sensitivity of magnetic sensors, the establishment of dose-response curves using MBS is unexplored and their capability to sensitively detect low concentrations of target molecules for diagnostic applications has remained unproven. In this study, we have exploited an alternative MBS concept based on the repositioning of the magnetic beads toward the most sensitive location on the spin valve sensors to allow for highly sensitive immunosensing over a wide range of target concentrations. Furthermore, we present the optimization of the magnetoimmuno assay, i.e., the surface chemistry, the blocking procedure, and the type of magnetic particle, for the highly sensitive and specific detection of S100betabeta, a diagnostic marker for stroke and minor head injury. Finally, a dose-response curve was established that illustrates that our MBS platform can specifically detect S100betabeta down to 27 pg/mL, while maintaining a broad dynamic detection range of approximately 2 decades.
Analytical Chemistry 12/2007; 79(22):8669-77. · 5.86 Impact Factor
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Tina Roeser,
Marion Ritzi,
Klaus S Drese,
Wim Laureyn,
Chengxun Liu,
Ciara K O'Sullivan,
Veli C Ozalp,
Christian Fermer, Olle Nilsson,
Siegfried Hauch,
Winfried Albert,
Elin Borgen,
Anders O H Nygre
Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 02/2007; 2007:6447-9.
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ABSTRACT: Progastrin-releasing peptide (proGRP) is a precursor of gastrin-releasing peptide, a hormone which is secreted from neuroendocrine cells. It has been shown to be a useful serum marker for small cell lung cancer. We raised monoclonal antibodies (MAbs) against proGRP with the primary aim of establishing a sensitive immunoassay. Immunization was performed with recombinant proGRP (amino acids 31-98) conjugated to thyroglobulin or with a DNP-modified peptide. Seven of the MAbs recognizing both recombinant and cell line-derived peptide were characterized and epitope-mapped. Based on cross-inhibition studies the antibodies could be categorized into three main groups. The molecular epitope assignment was studied by using phages displaying proGRP peptides, random peptide libraries displayed on phage and by pepscan analysis utilizing 10-mer biotinylated peptides. Two of the MAbs (E146, E172) bound to a defined region on the N-terminal part of proGRP(31-98), three recognized conformational-dependent epitopes in the middle of the peptide (E179, E180, E181) and two bound to the C-terminal part (E149, E168). Consensus sequences were obtained for MAbs E146, E149 and E168. The binding kinetics of the MAbs was determined by surface plasmon resonance, and a time-resolved immunofluorometric assay was established.
Tumor Biology 02/2007; 28(2):100-10. · 1.94 Impact Factor
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ABSTRACT: Squamous cell carcinoma antigen (SCCA) is a serological marker of squamous cell carcinomas (SCC). To study whether any of the SCCA isoforms would provide additional and more specific/sensitive clinical information than total SCCA, immunoassays specific for the different forms of SCCA (free SCCA2, total SCCA2, total SCCA1 and total SCCA) were developed. SCCA isoforms were determined before therapy and in follow-up samples from patients with cervical cancer and in serum samples from healthy females. Serum samples from patients with benign skin diseases (psoriasis and eczema) were also selected based on elevated SCCA levels. Rising levels of SCCA1 and SCCA2 were seen in patients with recurrence or progressive disease at the end of the study. The rise in SCCA2 was usually more prominent than that in SCCA1. The dominating serological form of SCCA was free SCCA2 both in healthy controls and in patients with cervical cancer. Both SCCA1 and SCCA2 were elevated in serum from cervical cancer patients and followed the clinical course of the disease during therapy monitoring. SCCA2 did not show improved tumor specificity as compared to SCCA1. A larger study is however necessary to make firm conclusions.
Tumor Biology 02/2006; 27(3):142-52. · 1.94 Impact Factor
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ABSTRACT: C203 and C242 are mouse monoclonal antibodies (MAbs) generated using a human colon carcinoma cell line. They recognize novel tumour-associated epitopes present in elevated levels in sera from patients with colon and pancreatic cancer. These epitopes were found to be co-expressed with sialylated Lewis2 on the CanAg molecule. To study the association and distribution of the epitopes of CanAg in sera, these new antibodies, together with C50, were used in different combinations in time-resolved fluoroimmunoassays. Relative serum concentrations were examined in patients with various types of carcinoma and in patients with ulcerative colitis and benign pancreatic, and hepatobiliary diseases. A double-determinant assay using C50 and C242 was shown to distinguish carcinoma from benign biliary and hepatocellular diseases better than a single-determinant assay based on C50 as both catching and tracing antibody. The number of sera with elevated CanAg levels from patients with benign obstructive biliary disease was 17 out of 29 using the single-determinant CASO assay. This was reduced to 4 out of 29 in the double-determinant assay. When sera from patients with liver cirrhosis were analyzed, 16 of 23 patients showed elevated CanAg levels with the C50-C50 combination, but only 4 of 23 patients had elevated antigen values using the C50-C242 assay. The increased specificity was obtained without loss of sensitivity. MAb C203 was evaluated both in a double-determinant combination with C50 and in an homologous assay, but did not contribute either Increased sensitivity or specificity as compared with C50-C50.
International Journal of Cancer 07/1991; 48(5):757 - 763. · 5.44 Impact Factor
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ABSTRACT: Using a radioimmunoassay we have determined serum levels of the carcinoma-associated antigen CA-50 in 266 patients with colorectal
cancer. Elevated CA-50 levels were found in Dukes’ A (15%), Dukes’ B (43%), Dukes’ C (31%) and Dukes’ D (65%). Patients who
had developed a recurrence had 66% elevated levels. 25% of resected patients with no evidence of disease also had elevated
CA-50 levels. From 139 patients operated on for a Dukes’ A-C, a rise in CA-50 levels from the pre- to the 6–9 month post-operative
sample was demonstrated in 12 cases in the absence of any clinical evidence for a recurrence. On follow-up, a recurrence later
developed in all these cases with lead times of CA-50 titre rises ranging from 5 to 40 months. A rise in CA-50 levels after
resection of a Dukes’ A-C is indicative of a recurrence and may precede any clinical evidence of disease by several months
or years. Data is also presented from 552 cases with colorectal cancer analysed with a immunoradiometric assay.
Medical Oncology 04/1988; 5(3):165-171. · 2.14 Impact Factor
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ABSTRACT: The binding specificity of thirteen mouse monoclonal antibodies reacting with Fuc-GM1, Fucα1–2Galβ1–3GalNAβ1–4(NeuAcα2–3)-Galβ1–4Glcβ1-1Cer, a ganglioside found to be associated with small cell lung carcinoma (O. Nilsson et al. (1984) Glycoconjugate J. 1, 43–49) was studied. The results are based upon radioimmunodetection of their binding to structurally related glycolipids adsorbed to microtiter plates or chromatographed on thin-layer plates. Four of thirteen antibodies reacted only with Fuc-GM1 and both the fucose and the sialic residues were necessary for binding. Optimal binding was obtained when the sialic acid was N-acetylneuraminic acid. When this sialic acid residue was substituted with N-glycoloylneuraminic acid the binding activity was reduced and up to 10-times more Fuc-GM1 was needed for detection. The ceramide composition did not influence the binding. The other nine monoclonal antibodies cross-reacted with glycolipids containing structures closely related to Fuc-GM1 and differed from the specific ones by recognizing a smaller portion of the carbohydrate moiety in Fuc-GM1 These results indicate that anticarbohydrate monoclonal antibodies, recognizing structures involving a large proportion of the sugar in the glycolipid, possess a high specificity and might be useful for detection of tumor-associated ganglioside antigen.
Biochimica et Biophysica Acta 03/1986; · 4.66 Impact Factor
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ABSTRACT: A hybridoma, C-50, obtained by fusion of mouse myeloma cells with spleen cells from a mouse immunized with cells from the colorectal carcinoma cell line COLO 205, produced antibodies that detected ganglioside antigen in human adenocarcinomas in many organs. The major ganglioside antigen fraction isolated from liver metastases of a pancreatic adenocarcinoma, behaving as a homogenous band on thin-layer chromatography, consisted of three different gangliosides. One of them, A (25%), had the same carbohydrate structure as the ganglioside antigen defined by monoclonal antibody 19-9, NeuAcα2–3Galβ1–3(Fucαl-4)GlcNAcβ1–3Galβ1–4Glc-Cer(Fuc-3'-isoLM1) (Magnani J.L., Nilsson B., Brockhaus M., Zopf D., Steplewski Z., Koprowski H. and Ginsburg V. (1982) J. Biol. Chem. 257, 14365–14369). The major ganglioside, B (60%), was the isomeric hexasaccharide ganglioside (NeuAcα2–3Galβ1–4(Fucα1–3)GlcNAcβ1–3Galβ1–4Glc-Cer (Fuc-3'-LM1) and the third ganglioside, C, was 6'-LM1, NeuAcα2–6Galβ1–4GlcNAcβ1–3Galβ1–4Glc-Cer (15%). Ganglioside B, isolated from human kidney, did not react with the C-50 MAb. Based on this result and on studies of COLO 205 cell induced tumours where the ganglioside antigen fraction only consisted of A, it is suggested that the C-50 MAb defines an antigen determinant present in A.
Biochimica et Biophysica Acta 04/1985; · 4.66 Impact Factor
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ABSTRACT: Characterization of monosialogangliosides of a small cell lung carcinoma showed a unique composition. The tumour contained GM2 and Fucosyl-GM1 (Fuc-GM1) with 2-hydroxy fatty acids as major ganglioside components. Three out of four other small cell carcinomas analysed contained also Fuc-GM1 as a characteristic ganglioside. Fuc-GM1 is suggested to be a small-cell lung carcinoma associated ganglioside antigen.
Glycoconjugate Journal 02/1984; 1(1):43-49. · 2.12 Impact Factor
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ABSTRACT: High doses of the lysosomotropic drug chloroquine result in lipid storage in many organs in animals. We used miniature pigs, type Gottingen, to study the lipid accumulation in skeletal muscle after chloroquine intoxication for more than 200 days. The lipids of the quadriceps muscle in intoxicated and in age-matched control pigs were characterized and determined. The lipid storage was larger in skeletal muscle than in any other organ of the intoxicated pigs. The concentration of phospholipids was increased threefold, acidic phospholipids relatively more than neutral ones. The lysosome-specific acidic phospholipid bis(monoacylglyceryl)phosphate content was almost 50-fold larger in the intoxicated pigs than in the controls. Cholesterol was increased slightly more than the phospholipids, but there was no particular accumulation of cholesteryl esters, which has been shown to occur in the liver. For the first time a storage of gangliosides, relatively more pronounced than of other lipids, was demonstrated in skeletal muscle in drug-induced lipidosis. The concentration of total gangliosides was increased 10–15-fold, and the pattern of gangliosides showed some distinct changes resulting in at least a 100-fold increase in the concentration of ganglioside GM2 (II3NeuAc-GgOse4Cer).
European Journal of Biochemistry. 05/1981; 116(3):565 - 571.
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ABSTRACT: Novel tumour-associated epitopes showing elevated levels in sera from patients with colon carcinoma were studied by means of monoclonal antibodies with respect to co-expression with the tumour-associated epitope CA50 on the cancer antigen (CanAg) glyco-conjugate complex. Co-expression of the different epitopes and CA50 was found on CanAg both from COLO 205 spent medium and sera from patients with colorectal cancer. In a few sera from patients with non-mucinous ovarian tumours, the CanAg complex was also found to express the CA125 epitope. The chemical characterisation showed that all of the novel epitopes on CanAg were of carbohydrate nature, and the results may suggest a structural relationship between several of them.
Tumor Biology 08/1970; 12(3):159-170. · 1.94 Impact Factor
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ABSTRACT: Squamous cell carcinoma antigen (SCCA), a member of the serine protease inhibitor (serpin) family, is a tumor-associated antigen and a serological marker for squamous cell carcinomas (SCC). Elevated serum levels are correlated with the clinical stage of the disease. Gene cloning has previously revealed two tandemly arrayed genes, SCCA1 and SCCA2. Using RT-PCR, an SCCA1/A2 transcript was identified in 6 out of 8 cell lines and the reciprocal SCCA2/A1 transcript was identified in 6 out of 8 analysed cell lines. Southern blot analysis showed an aberrant band pattern in 3 out of 5 cell lines. The cell lines demonstrating a normal band pattern corresponded to the cell lines where no fusion transcript was detected using PCR. Complex binding studies show that SCCA1/A2 binds to cathepsin G but not to cathepsin L, indicating that the SCCA1/A2 fusion protein has the specificity of SCCA2, but the transcription may be regulated as that of SCCA1. SCCA2/A1 reacts in the opposite way. The clinical relevance of these fusion transcripts is not yet known. Studies using primary tumours are underway to elucidate if these fusion transcripts are tumour specific and if they might be used as a diagnostic and prognostic marker for SCC.
Tumor Biology 24(1):46-52. · 1.94 Impact Factor
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ABSTRACT: The objectives of the present study were to use phage display to rescue the specificity of an IgM antibody and by the use of DNA shuffling to construct a sublibrary from which mutants with higher affinity could be selected. As a test system, a hybridoma cell line producing low-affinity IgM against recombinant pro-gastrin-releasing peptide (ProGRP) was chosen as starting material for construction of a single-chain Fv (scFv) phage library. One clone, pGRP5, demonstrating affinity for the antigen, was selected for the study. Random mutations were introduced into the scFv sequence by DNA shuffling, and mutants with raised affinity were selected by biopanning against recombinant ProGRP. Clones with affinities improved by approximately two orders of magnitude were selected after the first round of DNA shuffling. An additional 8- to 9-fold rise in affinity was demonstrated in mutants after the second round of mutagenesis. Sequence analysis demonstrated changes primarily in the complementarity-determining region (CDR) H1, CDR L1 and CDR H3 as compared to the original clone. Thus, by the use of phage display in combination with DNA shuffling, the specificity of an IgM antibody was rescued and the affinity was raised almost three orders of magnitude.
Tumor Biology 25(1-2):7-13. · 1.94 Impact Factor
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ABSTRACT: The aim of the study was to establish reference ranges and to explore the tumor specificities of two automated assays for MUC1. Sera from 124 female blood donors, 144 patients with benign disease of the breast, 69 patients with stage I, 75 with stage II, 89 with stage III and 38 patients with stage IV breast cancer were analyzed for MUC1 levels using two automated immunometric assays employing assay antibody pairs Ma695/Ma552 and BC2/GP1.4, respectively. All subjects were female. The Ma695/Ma552 assay yielded means of 13.86 (SD 6.55) kU/l for blood donors, 15.98 (SD 8.31) kU/l for benign disease, 15.83 (SD 7.92) kU/l for stage I, 15.01 (SD 8.03) kU/l for stage II, 33.80 (SD 66.53) kU/l for stage III and 469.22 (SD 906.61) kU/l for stage IV breast cancer. The BC2/GP1.4 assay gave means of 12.00 (SD 6.41) kU/l for blood donors, 14.68 (SD 9.33) kU/l for benign disease, 14.13 (SD 8.12) kU/l for stage I, 12.10 (SD 6.61) kU/l for stage II, 19.80 (SD 29.05) kU/l for stage III and 191.04 (SD 527.16) kU/l for stage IV breast cancer. Patients with benign diseases of the breast had slightly higher values than female blood donors with both assays leading to correspondingly different reference ranges. The Ma695/Ma552 assay had higher specificity for tumor MUC1 than the BC2/GP1.4 assay for all stages, and the study thus confirms the differences in tumor specificity for MUC1 assays.
Tumor Biology 23(6):315-23. · 1.94 Impact Factor
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ABSTRACT: Monoclonal antibodies were obtained by the immunization of mice with 6'LM1 (IV6NeuAc-nLcOse4Cer) adsorbed to Salmonella minnesota. The monoclonal antibodies showed a specificity for gangliosides with a terminal NeuAcα2-6Gal substitution, which was demonstrated in solid-phase binding assay and in liposome inhibition assay. Gangliosides with a NeuAcα2-6Gal substitution were minor components of different normal tissues. However, these gangliosides were enriched in carcinomas of many tissues, and were particularly enriched in most colorectal carcinomas and in lung carcinomas. 6'LM1 is a characteristic ganglioside in fetal intestinal mucosa (meconium). This ganglioside and other gangliosides with a terminal NeuAcα2-6Gal substitution might represent oncofetal antigens expressed in carcinomas owing to an activation of a ‘fetal’ sialyltransferase.
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism.
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ABSTRACT: Earlier studies (Baeckströmet al., J. Biol. (han.. 266: 21537-21547, 1991 ) have revealed that the colon carcinoma cell line COLO 205 produces two different proteins carrying the carcinoma-associated sialyl-Le" carbo hydrate epitope. One is the MUC1 mucin apoprotein, and the other pro tein is smaller and has not been characterized in detail. This paper de scribes a comparison of COLO 205 with three other colon carcinoma cell lines, aided by the use of a novel MUCl-reactive monoclonal antibody, Ma552. Ma552 reacted with H-CanAg, the MIO mucin purified from COLO 205, the binding increasing greatly upon partial deglycosylalion of H-CanAg with trifluoromethanesulfonic acid. This pattern of reactivity was in contrast with that of the MUCl-reactive monoclonal antibody HMFG-2, which did not recognize H-CanAg without prior deglyco- sylation. The nature of the epitope of Ma552 was further investigated using a synthetic peptide corresponding to the tandem-repeat sequence of the MIVI protein. When the peptide was used as an inhibitor of antibody binding to immobilized, partially deglycosylated H-CanAg mucin, Ma552 was inhibited, as was HMFG-2. Using short, immobilized synthetic pep- tides identical to parts of the MUC1 tandem repeat, the reactivity of Ma552 was mapped to the hexapeptide TRPAPG. Ma552 and C50, a monoclonal antibody reactive with sialyl-Le", were used in immunofluorometric assays to analyze gel filtration fractions of extracts and spent media from the colorectal carcinoma cell lines COLO 205, SW1116, LoVo, and I.S 174T. Using C50 in a homologous assay, all sialyl-Le'-carrying glycoproteins were detected. Among these, mucins based on the MUC1 apoprotein were identified using Ma552 and C50 in a combination assay. The results showed that sialyl-Le* was present on more than one glycoprotein not only in COLO 205 but also in SW1116 and LoVo. The Ma552/Eu-C50 assay revealed the presence of sialyl-Le"-car- rying MUC1 in COLO 205 as expected, as well as in SW1116. The presence of MUC1 in Ma552-reactive fractions was confirmed by deglycosylation followed by assaying with the monoclonal antibody HMFG-2. Furthermore, Northern blots revealed the presence of MUC1 mRNA only in the two Ma552-positive cell lines.
