Expression of MUC1 mucins in the subserosal layer correlates with postsurgical prognosis of pathological tumor stage 2 carcinoma of the gallbladder.

The overall outcome of pT(2) gallbladder carcinoma has not been favorable. Postsurgical recurrence at distant sites occurs in some cases, although the carcinoma was limited to the gallbladder wall. A high level expression of MUC1 mucins with sialylated carbohydrates (sialylated MUC1 mucins) is correlated with poor survival in intrahepatic bile duct carcinoma. In the present study, immunohistochemistry was performed to determine the expression level of sialylated MUC1 mucins, detected by a monoclonal antibody, MY.1E12, in 31 cases of pT(2) gallbladder carcinoma on which curative resections had been performed and to determine the correlation of the expression level of MY.1E12-reactive-MUC1 mucin with mode of recurrence and postsurgical survival. Immunostainings of the MUC1 mucin were recognized in different types of noncancerous pathological epithelia of the gallbladder except for intestinal metaplasia and cancerous epithelia. Immunohistochemical localization was classified into apical, cytoplasmic, and stromal types based on the predominant cellular distribution of MY.1E12-reactive-MUC1 mucin. In 31 cases of pT(2) carcinoma, the localization was apical type in 64%, cytoplasmic type in 71%, and stromal type in 48% of the cases at the deepest invading sites in the subserosal layer. Distant recurrences, i.e., peritoneal dissemination in 8 patients and liver metastasis in 3 patients, were seen in 8 (53%) of 15 cases of pT(2) carcinoma that had > or =10% of the cancerous epithelia showing stromal localization of the MUC1 mucin at the deepest invading sites and in 2 (12%) of 16 cases that had <10% of those showing the stromal localization. The postsurgical survival outcome was significantly poorer in the former than in the latter (P = 0.044). In pT(2) gallbladder carcinoma, the presence of MY.1E12-reactive-MUC1 mucin in the stroma adjacent to the cancerous epithelia in the subserosal layer correlates with the aggressiveness of the disease, such as the tendency to form distant recurrences. This phenotype may serve as a unique biological feature associated with the malignant behavior of pT(2) gallbladder carcinoma.     

Immunoperoxidase localization of a high-molecular-weight mucin recognized by monoclonal antibody 1D3

The distribution of an antigen recognized by murine monoclonal antibody 1D3 (Bhattacharya, M., Chatterjee, S.K., Barlow, J. J., and Fuji, H. Cancer Res., 42: 1650-1654, 1982) was investigated in various types of human malignant and normal adult tissues by indirect immunoperoxidase assay in fixed paraffin-embedded sections. One hundred percent of ovarian mucinous cystadenocarcinomas expressed high levels of the antigen with intense staining of 80 to 100% of the tumoral area, thus confirming our previous finding with radioimmunoassay and absorption analyses. About 51% of colonic carcinomas, 33% of gastric carcinomas, and 22% of pancreatic carcinomas were also positive for this high-molecular-weight mucoprotein antigen. All other ovarian and nonovarian carcinomas tested including carcinoma of lung, breast, endometrium, cervix, and prostate were not stained by 1D3. In addition, sarcomas, melanomas, and lymphomas also did not express any detectable level of the antigen. When surveyed against various normal adult tissues, 1D3 had reactivity limited to the colon. Normal colon, however, exhibited reduced staining intensities compared to tumors or to the apparently normal colon adjacent to tumors. The antigen thus appears to be a colorectal tissue-specific antigen showing increased levels in ovarian mucinous cystadenocarcinomas and in some gastrointestinal tumors. 1D3 antigen is a potential tumor marker for mucinous ovarian and colonic tumors.     

Immunohistochemical study of MUC5AC expression in human gastric carcinomas using a novel monoclonal antibody

In order to investigate the expression of MUC5AC mucin in normal gastric mucosa and gastric carcinomas, we produced 3 monoclonal antibodies (MAbs) using a MUC5AC synthetic peptide. The immunohistochemical study was performed using one of these MAbs (CLH2) which reacted with the different designs of peptides based on the MUC5AC tandem repeat and with native and deglycosylated mucin extracted from gastric tissues. CLH2 immunoreactivity was restricted to foveolar and mucopeptic neck cells in normal gastric mucosa. No reactivity was observed in type-1 intestinal metaplasia. Out of 66 gastric carcinomas, 42 (63.6%) expressed MUC5AC. Most diffuse carcinomas were positive (83.3%), whereas only 59.3% of intestinal and 40.0% of atypical carcinomas expressed MUC5AC (p < 0.05). Gastric carcinomas with mixed pattern showed immunoreactivity in diffuse areas and decreased immunoreactivity in intestinal areas. Every early gastric carcinoma expressed MUC5AC, in contrast to 58.6% of advanced carcinomas (p < 0.05). A trend toward decreased immunoreactivity was observed in deep areas of advanced carcinomas in comparison with the respective superficial areas. Taking together the specific staining of foveolar and mucopeptic neck cells and the absence of immunoreactivity in intestinal metaplasia, we conclude that MUC5AC expression may be used as a marker of gastric differentiation. This assumption is further supported by the finding of MUC5AC immunoreactivity in most diffuse carcinomas, which usually display morphologic and histochemical signs of gastric differentiation. The expression of MUC5AC in early gastric carcinomas, regardless of their histologic type, suggests that all gastric carcinomas retain at least some cells with a gastric phenotype during the first steps of neoplastic development. Int. J. Cancer 74:112–121. © 1997 Wiley-Liss, Inc.     

Enhanced tumor localization of monoclonal antibody by treatment with kininase II inhibitor and angiotensin II.

The effect of kininase II inhibitor, enalapril, on the delivery of monoclonal antibody A7 to the targeted tumor was investigated using athymic mice bearing human colon cancer, SW1116. Enalapril alone, which enhances tumor vascular permeability through the kinin-generating cascade, did not increase the uptake of 125I-labeled A7 (125I-A7) in SW1116 due to the systemic hypotension induced by its inhibitory effect on angiotensin converting enzyme. However, with combined angiotensin II (AT-II) and enalapril treatment, a 2-fold increase in the accumulation of 125I-A7 was seen when compared to A7 alone. This marked increase was presumably due to increased tumor vascular permeability induced by enalapril combined with the absence of hypotension due to the actions of AT-II. This approach might be useful in radioimmunodetection and immunotargeting chemotherapy using monoclonal antibody.     

Correlation of the immunohistochemical reactivity of mucin peptide cores MUC1 and MUC2 with the histopathological subtype and prognosis of gastric carcinomas

The expression of MUC1 and MUC2 mucin peptide core antigens in gastric carcinomas was studied by immunohistochemistry to determine correlations with TNM stage and histo-pathological classifications as well as a possible prognostic impact. Paraffin-embedded specimens from 128 gastric carcinomas with a minimal follow-up of 5 years were immunostained. In addition to a polyclonal antiserum generated against polymorphic epithelial mucin (MUC1) from human milk, 2 monoclonal antibodies (MAbs), HMFG2 (anti-MUC1) and 4F1 (anti-MUC2), were applied. Reactivity of carcinomas was correlated with the classifications of the UICC (TNM), WHO and Laurén. Correlations with overall survival were analyzed using the Kaplan and Meier product limit method. MUC1 immunoreactivity was associated with an advanced pTNM stage. The demonstration of both mucin species (MUC1, MUC2) displayed a statistically significant correlation with tubular/papillary vs. signet-ring cell differentiation as well as with intestinal-type vs. diffuse-type of tumor growth according to Laurén. In particular, MUC2 was only rarely detectable in signet-ring cell and diffuse-type tumors. MUC1 correlated with poor prognosis in all cases and the subgroup of stage I tumors. According to the histopathological classifications, a similar result was observed in signet-ring cell and diffuse-type carcinomas. In contrast, MUC2 reactivity was associated with a favourable prognosis of intestinal-type carcinomas. In the non-neoplastic gastric mucosa, both peptide cores were recognized in the superficial epithelium, whereas parietal cells contained only MUC1, and intestinal metaplasia almost exclusively MUC2 antigens. We conclude that the mucin peptide core antigens are suitable markers for the tubule-rich gastric carcinomas, which may in part be derived from intestinal metaplasia. In addition, MUC1 may exert a prognostic relevance and appears to be involved in the progression of diffuse-type tumors. Int. J. Cancer (Pred. Oncol.) 79:133–138, 1998.© 1998 Wiley-Liss, Inc.     

Molecular identification of a human carcinoma-associated glycoprotein antigen recognized by mouse monoclonal antibody FU-MK-1.

Mouse monoclonal antibody FU-MK-1, raised against a human gastric adenocarcinoma, recognizes an antigen (termed MK-1 antigen) present on the majority of carcinomas. The present study aimed to identify the MK-1 molecule and to establish its relationship to other carcinoma antigens. Immunoprecipitation studies of human tumor cell lines revealed that FU-MK-1 recognizes a monomeric membrane glycoprotein with two forms, 40 kDa (major form) and 42 kDa (minor form), and with a molecular mass of 35 kDa following treatment with the N-glycosylation inhibitor tunicamycin. The partial amino acid sequence of a main fragment of the MK-1 molecule obtained by spontaneous cleavage under hypotonic conditions was examined, and the 17 contiguous NH2-terminal amino acids were found to be identical with residues 81-97 of the 314-residue GA733-2 protein [Szala et al.; Proc. Natl. Acad. Sci. USA, 87, 3542-3546 (1990)]. Hence, the GA733-2 cDNA was cloned and the specificity of FU-MK-1 was confirmed using four recombinant forms of the GA733-2 antigen expressed in COS-1 cells. Immunoprecipitation with FU-MK-1 of the cell lysate transfected with the full-length GA733-2 cDNA revealed two bands corresponding to those obtained from the tumor cell lines. FU-MK-1 also precipitated three other recombinant proteins consisting of amino acids 1-265, 1-201, and 1-139 of the GA733-2 protein, respectively. Furthermore, immunoblotting analysis indicated that FU-MK-1 binds to a small fragment (6 kDa) generated from a tumor cell line under hypotonic conditions, suggesting that the FU-MK-1 epitope exists on the distal 6-kDa peptide of the extracellular domain of the GA733-2 molecule. We thus conclude that the MK-1 antigen is the GA733-2 antigen, which is currently being used as a target in clinical trials with monoclonal antibodies.     

Carbohydrate profiles shown by a lectin and a monoclonal antibody correlate with metastatic potential and prognosis of human lung carcinomas.

The expression of two carbohydrate markers--namely, 4C9 antigen, which is an Lex antigen, and the Dolichos biflorus agglutinin (DBA) binding site, which is an N-acetylgalactosamine marker--was examined histochemically in tumors and adjacent nontumorous tissues of 102 cases of human lung carcinomas. In nontumorous tissues, the DBA binding site was expressed more frequently than 4C9 antigen, and the DBA binding site had a tendency to be expressed more significantly than in tumor cells. Adenocarcinomas and well-differentiated tumors had a tendency to more cell surface staining. Patients with tumors that expressed DBA binding sites but not 4C9 antigen (4C9-, DBA+) had fewer metastasis and significantly better prognoses than patients with tumors of other carbohydrate profiles. Better prognosis of patients with 4C9-, DBA+ tumors was observed in those with blood group A antigen and those without it, and the better prognosis also was observed in patients with Stage I and IIIA disease.     

Selective inhibition of SCLC growth by the A12 anti-IGF-1R monoclonal antibody correlates with inhibition of Akt

Activation of the insulin-like growth factor-1 receptor (IGF-1R) by IGF-1 and IGF-2 plays a prominent role in the growth and survival of small cell lung cancer (SCLC) by potently activating the PI3K-Akt signal transduction pathway, which is also an important factor in the resistance of SCLC to chemotherapy. A12 is a fully human monoclonal antibody directed against the human IGF-1R that does not cross-react with the insulin receptor. In this study we have utilized A12 to determine the effects of selective antibody-mediated blockade of the IGF-1R on SCLC cell lines. Incubation with A12 resulted in a dose-dependent inhibition of IGF-1-stimulated IGF-1R and Akt activity, with maximal inhibition of approximately 75% at a concentration of 10 μg/ml in the H526 cell line. Growth of the H526 and H146 cell lines in serum was inhibited by a maximum of 50–70% in a dose-dependent fashion, which correlated well with the extent of Akt inhibition. However, growth of the H69 and WBA cell lines was unaffected by A12. Despite almost complete inhibition of IGF-1R phosphorylation by A12, Akt activity remained constitutively high in these cell lines. H526 transfectants expressing a constitutively active Akt allele also were resistant to A12. Treatment with A12 additively enhanced response to carboplatin in the H526 and H146 cell lines but had no effect on the H69 and WBA cell lines. Treatment of the H526 cell line with a combination of A12 and rapamycin was highly synergistic. These data suggest that growth inhibition and chemosensitization of SCLC by A12 is directly correlated with the ability to inhibit PI3K-Akt signaling, with those cell lines showing constitutive PI3K-Akt signaling displaying a high level of resistance to IGF-1R targeted therapy.     

A phase I study of PankoMab-GEX,a humanised glyco-optimised monoclonal antibody to a novel tumour-specific MUC1 glycopeptide epitope in patients with advanced carcinomas

BackgroundA phase I open-label dose-escalation study was conducted to define the safety, tolerability, and pharmacokinetics (PK) of PankoMab-GEX, a glyco-optimised humanised IgG1, with high affinity to a novel tumour-specific glycopeptide epitope of MUC1 (TA-MUC1) with excellent preclinical anti-tumour activity.Patients and methodsSeventy-four patients with advanced TA-MUC1-positive carcinomas received PankoMab-GEX intravenously every 3 (Q3W), 2 (Q2W), or 1 (QW) week in doses of 1–2200 mg in a three-plus-three dose-escalation design until disease progression (NCT01222624).ResultsNo maximum tolerated dose was reached. Adverse events were mainly mild-to-moderate infusion-related reactions (IRRs) by the first infusion in 45% of patients. Only one dose-limiting toxicity, a grade III IRR, was observed. PankoMab-GEX exhibited linear PK over all doses. Mean terminal half-life was 189 ± 66 h (Q3W), without dose dependency. A target trough level ≥50 μg/mL was reached after one infusion with doses ≥1700 mg Q3W in 80% of patients. Clinical benefit in 60 evaluable patients included one complete response in a patient with ovarian cancer treated 483 d and confirmed disease stabilisation in 19 patients lasting a median (range) of 23 (10–109) weeks. All but two of the patients with clinical benefit had received a compounded total dose ≥700 mg over a 3-week period, including 8 of 12 (67%) patients with ovarian cancer.ConclusionPankoMab-GEX is safe, well tolerated, and showed promising anti-tumour activity in advanced disease. A phase IIb study is ongoing evaluating the efficacy of PankoMab-GEX as a maintenance therapy in advanced ovarian cancer.     

MUC1 isoform specific monoclonal antibody 6E6/2 detects preferential expression of the novel MUC1/Y protein in breast and ovarian cancer.

The products of the MUC1 gene are known to be highly expressed in human breast cancer cells. The best characterized MUC1 protein is a polymorphic, type 1 transmembrane molecule containing a large extracellular domain composed primarily of a variable number of 20 amino acid tandem repeats. We have recently identified a novel protein product of the MUC1 gene, the MUC1/Y protein, that is also a transmembrane protein but is devoid of the tandem repeat array and its immediate flanking sequences. To analyze its expression in tumor cells we generated monoclonal antibodies directed against the MUC1/Y extracellular domain (anti-MUC1/Yex MAbs). Epitope mapping identified the MAb, 6E6, which recognized the MUC1/Y isoform with exquisite specificity- the repeat-array-containing MUC1 isoform could not compete out this immunoreactivity. A 30mer peptide which is unique for MUC1/Y and corresponds to the "join" region generated by the MUC1/Y specific splice, abrogated all 6E6 MAb immunoreactivity towards MUC1/Y. Immunoprecipitation of the MUC1/Y protein with 6E6 MAbs revealed that, in contrast with the proteolytic cleavage of the tandem-repeat-array-containing MUC1 isoform, MUC1/Y is not cleaved. Flow cytometry analyses using the 6E6 MAbs demonstrated that the MUC1/Y isoform is expressed on the cell surface of both MCF-7 breast cancer cells and malignant epithelial cells present in effusions obtained from breast and ovarian cancer patients. Our results unequivocally establish that the MUC1/Y protein is expressed on the surface of breast cancer cells and cells of other epithelial malignancies. The anti-MUC1/Y MAbs described here can target MUC1/Y expressing tumor cells in vivo and are likely to be important reagents both for epithelial tumor diagnosis and immunotherapy.     

Biosynthesis and glycosylation of the carcinoma-associated antigen recognized by monoclonal antibody KS1/4.

Monoclonal antibody KS1/4 recognizes an epitope expressed on the cell surface of human adenocarcinoma cells and certain epithelia. Western blotting analyses of tumor cell extracts utilizing KS1/4 reveal staining of a major Mr 40,000 band and a minor Mr 42,000 band. Both components are also detectable in KS1/4 immunoprecipitates of L-[35S]methionine- and D-[3H]glucosamine-labeled human lung tumor cell extracts. When synthesis occurs in the presence of tunicamycin or when the immunoprecipitates are treated with peptide:N-glycosidase F, a single polypeptide component (Mr 37,000) is precipitated. Immediately following translation, digestion of Mr 40,000 and Mr 42,000 glycoproteins with endo-beta-N- acetylglucosaminidase H also yields a single polypeptide component at Mr 37,000. However, over a 3-h period beginning at 10 min posttranslation, a Mr 39,000 major component and a Mr 41,000 minor component gradually appear in the endo-beta-N-acetylglucosaminidase H digests as the Mr 37,000 component gradually disappears. Analysis of tryptic glycopeptides derived from the Mr 40,000 and 42,000 components suggests that the two components differ by the addition of one extra oligosaccharide to the Mr 42,000 component. Nonequilibrium pH gradient electrophoresis/sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of KS1/4 immunoprecipitates resolves each of the two components into multiple spots. Digestion of the KS1/4 immunoprecipitates with neuraminidase prior to two-dimensional analysis or immunoprecipitation of short pulse-labeled extracts reduces the number of spots to three each at the Mr 40,000 and Mr 42,000 positions. Digestion of the KS1/4 immunoprecipitates with peptide:N-glycosidase F, immunoprecipitation of extracts labeled in the presence of tunicamycin, or endo-beta-N-acetylglucosaminidase H digestion of immunoprecipitates of short pulse-labeled extracts prior to two-dimensional analysis results in a single series of Mr 37,000 spots, suggesting that the polypeptide portions of the Mr 40,000 and Mr 42,000 components may be identical. Endo-beta-N-acetylglucosaminidase H digestion of KS1/4 immunoprecipitates of short pulse-labeled extracts, followed by nonequilibrium pH gradient electrophoresis, V8 protease digestion, and polyacrylamide gel electrophoresis revealed an apparently identical set of polypeptides derived from each of the three Mr 37,000 spots, suggesting that the three spots derive from highly similar polypeptides.     

Expression of {beta}-catenin, MUC1 and c-met in diffuse-type gastric carcinomas: correlations with tumour progression and prognosis

Previous studies on the immunoreactivity of β-catenin, MUC1 and c-met in gastric carcinomas regarding survival and clinico-pathological features led to contradictory results. Therefore, a series of 94 diffuse-type and mixed-type subcardial gastric carcinomas according to the Laurén classification were investigated to elucidate possible correlations with clinico-pathological and prognostic data. An immunohistochemical study was performed to detect the expression of β-catenin, MUC1 and c-met. Loss of membranous/cytoplasmic β-catenin expression in the tumour centre correlated with pT, loss at the invasion front with pTNM stage. MUC1 expression in the tumour centre correlated with lymph node metastasis and pTNM stage. c-Met did not show such associations. In multivariate survival analysis, loss of membranous/ cytoplasmic β-catenin expression as well as a strong MUC1 expression at the tumour invasion front represent independent predictors of a worse prognosis. On the other hand, c-met expression did not exhibit any prognostic value in this study.     

Characterization of a new MUC1 monoclonal antibody (VU-2-G7) directed to the glycosylated PDTR sequence of MUC1.

A monoclonal antibody (MAb), VU-2-G7, was generated against a synthetic 60-mer MUC1 triple tandem repeat peptide with N-acetyl-galactosamine (GalNAc) O-linked to the threonine in the PDTR region of each repeat (3M GalNAc). VU-2-G7 and 8 MUC1 MAbs (VU-3-C6, VU-4-H5, 139H2, A76-A/C7, VU-12-E1, BCP9, MF11 and BW835) were tested against various glycosylated and nonglycosylated MUC1 tandem repeat peptides. VU-2-G7 showed strong reactivity with its immunogen, 3M GalNAc, and much lower reactivity with the nonglycosylated 60-mer MUC1 triple tandem repeat peptide. VU-2-G7 showed no reactivity with a 60-mer MUC1 triple tandem repeat peptide modified at the PDTR region or with a 60-mer MUC1 triple tandem repeat peptide with 3 GalNAc per repeat outside the PDTR region (9M GalNAc). In ELISA and flow cytometry, VU-2-G7 ubiquitously reacted with 4 MUC1-expressing breast cancer and 2 ovarian cancer cell lines and with a MUC1-gene-transfected Chinese hamster ovary cell line. The reactivity of VU-2-G7 was always higher than that of VU-4-H5, raised against a nonglycosylated 60-mer MUC1 triple tandem repeat peptide. Immunohistochemical staining of paraffin sections of breast and ovarian tumor tissues showed strong binding of VU-2-G7 predominantly at the cell membrane. The dominant epitope of VU-2-G7 is in the glycosylated PDTR motif of the MUC1 tandem repeat, and this epitope is abundantly present on the surface of tumor cell lines and breast and ovarian tumor tissues. Given the ubiquitously aberrant glycosylation of MUC1 in malignant cells, the production of MAbs against highly purified glycosylated MUC1 tandem repeat peptides may yield MAbs better suited for the immunotherapy of carcinomas than those available at the moment.     

Autoantibodies to aberrantly glycosylated MUC1 in early stage breast cancer are associated with a better prognosis

Introduction  

Detection of serum biomarkers for early diagnosis of breast cancer remains an important goal. Changes in the structure of O-linked glycans occur in all breast cancers resulting in the expression of glycoproteins that are antigenically distinct. Indeed, the serum assay widely used for monitoring disease progression in breast cancer (CA15.3), detects a glycoprotein (MUC1), but elevated levels of the antigen cannot be detected in early stage patients. However, since the immune system acts to amplify the antigenic signal, antibodies can be detected in sera long before the antigen. We have exploited the change in O-glycosylation to measure autoantibody responses to cancer-associated glycoforms of MUC1 in sera from early stage breast cancer patients.     

Generation and characterization of a high-affinity monoclonal antibody for MUC1 measurement in breast cancer

Breast mucin is secreted by breast tumor cells and serves as a marker for breast cancer. Thus, antibodies against breast mucin will be valuable in the development of immunotherapy and laboratory diagnostic tests. Monoclonal antibodies (MAbs) against breast cancer-associated antigen were generated and characterized. Balb/c mice were immunized with breast cancer-associated antigen CA15-3, and subsequently splenocytes from immunized mice were fused with myeloma cells. After fusion, culture supernatants from hybridomas surviving HAT medium were screened by enzyme-linked immunosorbent assay (ELISA). A total of eight hybridomas producing MAbs against breast cancer showed significant levels of antibody activity against CA15-3. Two selected stable hybridomas were adapted into CELLine CL 350 bioreactors, and the MAbs produced were characterized for their subclass, specificity, and affinity. The MAbs were of high specificity and affinity as shown by ELISA. The MAbs produced may represent a powerful tool and are considered promising reagents for use in diagnosis and detection of early stage of the disease.     

HMMC-1: a humanized monoclonal antibody with therapeutic potential against Müllerian duct-related carcinomas.

PURPOSE: The purpose of this research was to generate a human monoclonal antibody specific to gynecological cancers and to evaluate such an antibody as therapy for gynecological cancers. EXPERIMENTAL DESIGN: Transchromosomal KM mice were immunized with the human uterine endometrial cancer cell line SNG-S. Hybridomas were constructed between spleen cells from KM mice and mouse myeloma cells. Reactivity of the antibody was evaluated by immunohistochemistry of pathological specimens of gynecological cancers. Cytotoxicity of HMMC-1 against SNG-S cells was tested by in vitro cytotoxicity assays. The epitope of HMMC-1 was determined by transfection with a panel of glycosyltransferase cDNAs and by inhibition assays with chemically synthesized oligosaccharides. RESULTS: HMMC-1 is a human IgM monoclonal antibody that reacts positively with mullerian duct-related carcinomas with positive rates of 54.6% against uterine endometrial adenocarcinoma, 76.9% against uterine cervical adenocarcinoma, and 75.0% against epithelial ovarian cancer. HMMC-1 does not react with normal endometrium at proliferative or secretory phases, normal uterine cervix, or normal and malignant tissue from other organs, whereas it reacts weakly with the epithelium of the gall bladder and the collecting duct of the kidney. HMMC-1 exhibits antigen-dependent and complement-mediated cytotoxicity. Upon cotransfection with cDNAs encoding two glycosyltransferases required for fucosylated extended core 1 O-glycan, mammalian cells express HMMC-1 antigen. Finally, binding of HMMC-1 to SNG-S cells is inhibited by synthetic Fucalpha1-->2Galbeta1-->4GlcNAcbeta1-->3Galbeta1-->3GalNAcalpha1-octyl. CONCLUSIONS: These results indicate that HMMC-1 specifically recognizes a novel O-glycan structure. The unique specificity and cytotoxicity of HMMC-1 strongly suggest a therapeutic potential of this antibody.     

Expression of cyclooxygenase-2 in the subserosal layer correlates with postsurgical prognosis of pathological tumor stage 2 carcinoma of the gallbladder

Postsurgical recurrence at distant sites frequently occurs in pathological tumor stage 2 (pT(2)) carcinoma of the gallbladder even though the carcinoma is limited to the gallbladder wall. Little is known, however, about the molecular events leading to its development and progression. A large body of evidence suggests that cyclooxygenase-2 (COX-2) is up-regulated in carcinoma tissues and plays roles in promoting cell-proliferation, growth and metastasis of carcinoma cells. In the present study, immunohistochemistry was performed to determine the expression levels of COX-2 in the subserosal layer of 33 cases of pT(2) gallbladder carcinoma in which curative resections had been performed and to determine the correlations of the expression levels of COX-2 with mode of recurrence and postsurgical survival. Immunostaining of COX-2 in the epithelia was recognized in more than 80% of normal epithelia, noncancerous pathological lesions of the gallbladder except for intestinal metaplasia and pT(1-4) carcinoma specimens. Intense staining was observed in large percentages of hyperplastic lesions (65%), pT(2) carcinoma specimens (76%) and pT(3) and pT(4) carcinoma specimens (64%) compared to the percentages of normal epithelia and other pathological lesions (0-25%). Intense staining was also observed in the adjacent stroma in pT(2) carcinoma specimens (33%) and in those in pT(3) and pT(4) carcinoma specimens (43%) but only in small percentages of the stroma adjacent to normal epithelia and pathological lesions (0-8%). In situ hybridization confirmed the existence of COX-2 mRNA in both the cancerous epithelia and adjacent stroma of pT(2)-pT(4) carcinomas. In 33 cases of pT(2) carcinoma, distant recurrence, i.e., liver metastasis, was seen in 3 of 9 cases of pT(2) carcinoma (33%, P<0.05) with intense stromal staining in the subserosal layer and in 1 of 24 cases (4%) without intense staining, whereas no significant correlation was found between parameters of pathological malignancies (histological grade, lymphatic permeation, venous permeation and lymph node metastasis) and the intensity of stromal staining in the subserosal layer. The postsurgical survival outcome was significantly poorer in the former than in the latter (p = 0.010). In pT(2) gallbladder carcinoma, upregulation of COX-2 in the stroma adjacent to the cancerous epithelia in the subserosal layer correlates with the aggressiveness of the disease, such as the tendency to form distant recurrences. This phenotype may serve as a unique biological feature associated with the malignant behavior of pT(2) gallbladder carcinoma.