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R C Bast

Publications and source records attributed to R C Bast.

At least 73 records · Page 4Linked to original sources
PubMed1997

Is OVX1 a suitable marker for endometrial cancer?

The single most common cause leading to the diagnosis of endometrial cancer is postmenopausal bleeding. Although most patients with early-stage disease (FIGO stage I and II) can be cured, prognosis worsens considerably with increasing stage. While serum CA 125 levels are elevated only in a significant proportion of patients with advanced disease, recently a new serum marker (OVX1) for the detection of early-stage endometrial cancer was reported. Serum OVX1 levels were measured using an OVX1 radioimmunoassay (RIA) or enzyme immunoassay (EIA) in 192 patients with endometrial cancer. CA 125 levels were measured in 112 patients using the CIS ELSA CA 125 kit. Apparently healthy females had mean serum OVX1 levels measured with the OVX1-EIA of 1.34 +/- 0.74 U/ml, while patients with endometriosis had mean OVX1 serum levels of 3.15 +/- 2.45 U/ml. The mean OVX1 serum level for endometrial cancer patients was 2.00 +/- 1.32 U/ml. These values were 2.76 +/- 1.62, 6.10 +/- 4.66, and 5.37 +/- 3.49, respectively, using the OVX1-RIA assay. Applying a cutoff value of 2.8 U/ml, serum OVX1-EIA levels in endometrial cancer patients were increased in 25 of 127 patients (19.7%) with stage I disease, 5 of 17 patients with stage II (29.4%), 5 of 22 patients (22.7%) with stage III, and 4 of 11 patients (36.4%) with stage IV disease. Using the OVX1-RIA and a cutoff of 7.2 U/ml, serum levels were increased in 22 of 127 (17.3%) stage I, 6 of 17 (35.3%) stage II, 5 of 22 (22.7%) stage III, and 6 of 11 (54.5%) stage IV patients. Serum CA 125 levels, determined in a total of 112 patients, were elevated above 35 U/ml in 12 of 79 patients (15.2%) with stage I, 4 of 12 patients (33.3%) with stage II, 8 of 13 patients (61.5%) with stage III, and all of 8 patients (100%) with stage IV disease. While a good correlation between serum CA 125 levels and the clinical stage of the disease was found, no correlation could be detected for OVX1 and stage.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1997

Radioiodinated antibody targeting of the HER-2/neu oncoprotein.

The HER-2/neu oncogene encodes a 185 kDa phosphoglycoprotein that is overexpressed in breast, ovarian and other cancers. Seven monoclonal antibodies reactive with oncoprotein were labeled with 131I. In vitro experiments with SKOv3 9002-18 cells determined binding affinity, internalization and degradation. The biodistribution of these antibodies in comparison to 125I-labeled nonspecific antibody was measured in athymic mice with SKOv3 9002-18 ovarian carcinoma xenografts. Antibody 520C9 exhibited the highest and most specific retention in tumor, peaking at 17.4 +/- 5.6% ID/g at 24 h.

Animals↗
PubMed1997

Improving physician-patient communication in cancer care: outcome of a workshop for oncologists.

BACKGROUND: Physicians caring for cancer patients receive little formal training in difficult communications such as breaking bad news, discussing life support, and addressing patients' emotional concerns. METHODS: The authors conducted a three-day workshop in communication skills for nine oncology attendings and three fellows. Topics for the workshop were selected by participants by a pre-workshop questionnaire. Small groups of four to five participants interviewed simulated patients who role-played scripts based on the selected topics. Sessions on self-awareness and one on planning for continuing the work of the group after the workshop were included. RESULTS: Responses to pretest and posttest questionnaires showed that the workshop increased the participants' confidence in a number of communication areas and also in managing physician burnout. Process issues such as patient death and expectations for cure were also discussed. CONCLUSION: Interactive workshops offer a promising way of teaching communication skills and aspects of the physician-patient relationship to oncologists. Conclusions regarding outcome, however, are preliminary and tentative, and long-term results are uncertain.

Cancer Care Facilities↗
PubMed1997

The significance of tumor contamination in the bone marrow from high-risk primary breast cancer patients treated with high-dose chemotherapy and hematopoietic support.

We studied the incidence and significance of tumor cell contamination of the bone marrow or peripheral blood progenitor cells of patients who had high risk primary breast cancer involving 10 or more axillary lymph nodes and who received high dose cyclophosphamide, cisplatin, and carmustine with hematopoietic support as consolidation following standard dose adjuvant chemotherapy. The autologous hematopoietic cell products were evaluated in 85 eligible patients. Eighty-three samples were available from the time of bone marrow harvest, and peripheral blood progenitor cells were evaluated from 57 of the 65 patients who additionally received these products. The screening technique utilized a panel of four anti-breast cancer monoclonal antibodies and an immunohistochemical technique. Thirty (36%) of the 83 evaluable patients had tumor cell contamination of the bone marrow. Only 2 (4%) of the 57 patients had tumor cell contamination of the peripheral blood progenitor cells. Tumor cell contamination of the bone marrow was associated with shorter disease-free survival and overall survival. In addition, the higher the number of tumor cells identified, the shorter disease-free and overall survival. There was no relationship between the tumor cell contamination of the bone marrow and the site of relapse. The combination of the log of the number of tumor cells +1 and number of positive lymph nodes predicted both disease-free and overall survival. Tumor cell contamination of the bone marrow from the harvest is associated with shorter disease-free and overall survival for patients who were treated with standard dose chemotherapy followed by consolidation with high dose alkylating agents and hematopoietic support. It is unclear what role the contaminating tumor cells have in relapse, and they may just be a high-risk marker. A comparison with other prognostic factors and characteristics of the tumor may determine the significance of the tumor contamination of the bone marrow.

Adult↗
PubMed1997

Heregulin and agonistic anti-p185(c-erbB2) antibodies inhibit proliferation but increase invasiveness of breast cancer cells that overexpress p185(c-erbB2): increased invasiveness may contribute to poor prognosis.

Overexpression of p185(c-erbB2) (p185/NEU/HER2) by tumor cells is associated with a poor prognosis in many but not all studies of breast and ovarian cancer. The poor prognosis associated with overexpression of p185(c-erbB2) could result from an increased growth rate or increased invasive potential. The p185(c-erbB2) tyrosine kinase receptor can be activated with agonistic antibodies directed against p185(c-erbB2) or with the ligand heregulin through a combinatorial interaction with erbB3 or erbB4. Consequently, we have asked whether heregulin or agonistic antibodies increase anchorage-independent growth or invasiveness of the SKBr3 breast cancer cell line, which overexpresses p185(c-erbB2). Incubation of SKBr3 breast cancer cells with heregulin inhibited anchorage-independent growth while enhancing tyrosine phosphorylation of p185(c-erbB2). Heregulin treatment also increased adhesion of SKBr3 cells to plastic and increased invasiveness of tumor cells into Matrigel membranes while increasing expression of the CD44 (HCAM) and CD54 (ICAM-1) adhesion molecules. Tumor cell invasion of Matrigel membranes was partially blocked by either anti-CD44 or anti-CD54 antibodies, indicating a role for these adhesion molecules in the invasion process. Compatible with the increased invasiveness, heregulin increased expression of the matrix metalloproteinase 9. In contrast, the agonistic anti-p185(c-erbB2) antibody ID5 induced only a subset of the responses induced by heregulin. ID5 induced tyrosine phosphorylation of p185(c-erbB2), increased invasiveness, and increased expression of CD44. Despite the similarity of effects of ID5 and heregulin on some outcomes, the ID5 antibody failed to increase adhesion to plastic, expression of CD54, or production of matrix metalloproteinase 9. Thus, the ID5 agonistic anti-p185(c-erbB2) antibody mimics rather than antagonizes some but not all of the actions of heregulin. Moreover, the poor prognosis of breast and ovarian cancers that overexpress p185(c-erbB2) could relate in part to enhanced invasiveness rather than to increased proliferative capacity.

Antibodies, Neoplasm↗
PubMed1996

Tumor marker utility grading system: a framework to evaluate clinical utility of tumor markers.

Introduction of tumor markers into routine clinical practice has been poorly controlled, with few criteria or guidelines as to how such markers should be used. We propose a Tumor Marker Utility Grading System (TMUGS) to evaluate the clinical utility of tumor markers and to establish an investigational agenda for evaluation of new tumor markers. A Tumor Marker Utility Grading Worksheet has been designed. The initial portion of this worksheet is used to clarify the precise characteristics of the marker in question. These characteristics include the marker designation, the molecule and/or substance and the relevant alteration from normalcy, the assay format and reagents, the specimen type, and the neoplastic disease for which the marker is being evaluated. To determine the clinical utility of each marker, one of several potential uses must be designated, including risk assessment, screening, differential diagnosis, prognosis, and monitoring clinical course. For each of these uses, associations between marker assay results and expected biologic process and end points must be determined. However, knowledge of tumor marker data should contribute to a decision in practice that results in a more favorable clinical outcome for the patient, including increased overall survival, increased disease-free survival, improvement in quality of life, or reduction in cost of care. Semiquantitative utility scales have been developed for each end point. The only markers recommended for use in routine clinical practice are those that are assigned utility scores of "++" or " " on a 6-point scale (ranging from 0 to ) in the categories relative to more favorable clinical outcomes. Each utility score assignment should be supported by documentation of the level of evidence used to evaluate the marker. TMUGS will establish a standardized analytic technique to evaluate clinical utility of known and future tumor markers. It should result in improved patient outcomes and more cost-efficient investigation and application of tumor markers.

Biomarkers, Tumor↗
PubMed1996

Expression of cell regulatory proteins in ovarian borderline tumors.

BACKGROUND: Tumors of borderline malignancy are still a controversial subgroup of ovarian neoplasms. The expression of several cell regulatory proteins was studied to characterize the molecular phenotype of these tumors, and to compare them with their benign and malignant counterparts. METHODS: Specimens from 22 patients with tumors of borderline malignancy (11 serous and 11 mucinous tumors), 12 patients with benign tumors, and 16 patients with invasive ovarian carcinomas were evaluated for expression of epidermal growth factor receptor (EGFR), HER-2/neu, PTP1B, and p53 by immunohistochemical techniques. RESULTS: One or both of the tyrosine kinase growth factor receptors EGFR and HER-2/neu was expressed by 42% of benign, 59% of borderline, and 81% of malignant ovarian tumors. EGFR was expressed in a significantly greater fraction of malignant lesions (69%) than borderline lesions (18%) (P< 0.004). EGFR expression was not observed among the 11 mucinous borderline tumors. HER-2/neu was expressed by 50% of borderline tumors and was not a marker for malignancy. The tyrosine phosphatase PTP1B was expressed by a similar fraction of benign (17%), borderline (27%), and malignant (19%) tumors. The number of cases studied precluded correlation of kinase and phosphatase activity. However, among 12 tumors with PTP1B expression, 9 also expressed EGFR or HER-2/neu. Overexpression of p53 was observed only in malignant serous tumors and was not found in malignant mucinous, borderline, or benign lesions. CONCLUSIONS: Either EGFR or HER-2/neu was detected in a majority of borderline cancers. PTP1B was present only in a minority of these cancers. Frankly malignant serous lesions differed from borderline and benign tumors with regard to expression of EGFR and overexpression of p53.

Carcinoma↗
PubMed1996

Transfection of human ovarian cancer cells with the HER-2/neu receptor tyrosine kinase induces a selective increase in PTP-H1, PTP-1B, PTP-alpha expression.

Protein tyrosine phosphorylation is a key regulator of cell growth regulation and, when aberrant, is linked with the process of oncogenic transformation. Since tyrosine phosphatases (PTP) reverse phosphorylation mediated by tyrosine kinases (PTK), it has been hypothesized, but insufficiently studied to date, that PTPs function as tumor suppressors. Alternatively, PTPs may augment signal transduction by repriming substrates. To begin to assess the role of PTPs in ovarian cancer cell growth regulation, PTP partial cDNAs were cloned from the OVCA 433 ovarian cancer cell line using RT/PCR and degenerate oligonucleotide primers for the PTP consensus domain. Thirteen partial cDNAs were isolated, the sequences of which, when compared to GenBank, suggested that they were derived from PTP family members. These included PTP-alpha, PTP-gamma, LAR, PTP-delta, T-cell PTP, PTP-2A(1D), PTP-1B, PTP-1C, PTP-H1, PTP-PEST, PTP-Gallus, and two isolates which potentially represent novel PTPs. Steady-state expression analyses revealed that PTP-1B expression was undetectable in normal epithelium but was expressed in four of five ovarian cancer cell lines. In contrast, the expression of two SH2-containing PTPs, PTP-1C and PTP-2A, was detected in the normal ovarian epithelium but lost from one or more ovarian cancer cell lines. Finally, PTP-1B, PTP-alpha, and PTP-H1 expression was increased following HER-2/neu transfection of ovarian cancer cell lines. These results suggest that both normal ovarian epithelial cells and ovarian cancer cells express multiple PTPs. Further, some PTPs are differentially expressed between normal ovarian epithelium and ovarian cancer cells. Intriguingly, the transfection and increased expression of the prognostically significant HER-2/neu PTK induced a selective increase in the expression of the PTP-alpha, PTP-1B, and PTP-H1 tyrosine phosphatases.

Base Sequence↗
PubMed1996

Characterization of gelatinases linked to extracellular matrix invasion in ovarian adenocarcinoma: purification of matrix metalloproteinase 2.

Substantial evidence indicates that proteolytic degradation of the extracellular matrix is necessary for invasion and metastasis by cancer cells. Our previous work has demonstrated elevated secretion by cultured ovarian adenocarcinoma cells of two gelatinolytic metalloproteinases, a 72-kDa enzyme resembling matrix metalloproteinase 2 (MMP-2) and a 92-kDa enzyme resembling MMP-9 (Moser et al, Int. J. Cancer 56, 552-559, 1994). To assess the potential in vivo relevance of these enzymes, we have examined ovarian carcinoma ascites using gelatin substrate zymography. MMP species identical to those secreted from several well-characterized ovarian adenocarcinoma cell lines were found in the majority of ascites: MMP-2-like gelatinase (23 of 23 cases) and MMP-9-like gelatinase (18 of 23 cases), suggesting a prevalence of these species in the ovarian carcinoma microenvironment and their availability for tumor-associated proteolysis. The contribution of these proteinases to ovarian cancer invasion was further demonstrated by experiments measuring tumor cell-mediated proteolysis of native endothelial cell extracellular matrix (ECM) and tumor cell invasion of reconstituted basement membrane (Matrigel). These data showed that secretion of type IV collagenase activity by a series of independently isolated ovarian adenocarcinoma cell lines correlated well with the ability of these cells to proteolyze the ECM and invade the basement membrane. Furthermore, we have identified and characterized an ovarian carcinoma-associated gelatinase, the 72-kDa MMP found in conditioned media of the DOV 13 cell line, as MMP-2. This enzyme was identical to the previously described MMP-2 from other sources by Western blot, amino terminal sequence, and substrate specificity. Additionally, a large portion of the MMP-2 activity found in DOV 13 conditioned media is active without organomercurial treatment, suggesting that ovarian cancer cells have an endogenous activator of the zymogen. Together, these data suggest that ECM proteolysis mediated by tumor-associated proteinases plays an important role in the invasion and/or metastasis of ovarian carcinoma.

Adenocarcinoma↗
PubMed1996

Immunocytochemical detection of breast cancer cells in marrow and peripheral blood of patients undergoing high dose chemotherapy with autologous stem cell support.

Detection of small numbers of breast cancer cells is important in staging the disease and can be helpful in assessing the efficacy of purging regimens prior to autologous stem cell infusion. Immunohistochemical methods are potentially useful and broadly applicable for this purpose since they are simple to perform, sensitive, and may be quite specific. We have used a combination of four monoclonal antibodies [260F9, 520C9, 317G5 (Baxter Corp); BrE-3 (Dr. R. Ceriani)] against tumor cell surface glycoproteins in a sensitive immunocytochemical assay to identify breast tumor cells in bone marrow and peripheral blood. Immunostained cytospin preparations were fixed prior to staining to preserve cytological details of immunopositive cells. After immunostaining, slides were counterstained with hematoxylin to confirm the identify of labeled cells. In cytocentrifuge experiments in which small numbers of CAMA human breast tumor cells were added to bone marrow mononuclear cells, a linear relationship between the number of tumor cells added and the number of tumor cells detected was obtained over a broad range of tumor cell concentrations. The probability of detecting tumor cells was dependent on the number of cytocentrifuge slides examined. When ten slides (5 million cells) were examined, the probability of detecting tumor at a concentration of 4 tumor cells per million bone marrow mononuclear cells was 98%. In clinical specimens, tumor cells were detected in marrow aspirates from 73 of 240 (30%) patients undergoing autologous transplantation, including 70 (37%) of 190 patients with clinical stage IV disease, 0 of 7 patients with clinical stage III disease, and 3 of 43 (7%) patients with clinical stage II disease. Seventy-three of 657 peripheral blood specimens from 26 of 155 patients (17%) contained breast cancer cells with counts ranging from 1 to 97 tumor cells per million leukocytes. Tumor cells were most frequently found in the blood of patients with stage IV disease [21 of 107 (20%)] but were also found in a substantial number [5 of 44 (11%)] of patients with stage II disease. Positive selection of CD34-positive hematopoietic progenitor cells as well as negative purging methods such as incubation with 4-hydroxyperoxy-cyclophosphamide (4-HC) were evaluated with respect to tumor cell depletion. Selection of CD34-positive progenitor cells from bone marrow or peripheral blood resulted in log reduction of 1 to > 4 tumor cells reinfused at autologous transplantation. A lesser log reduction (up to 1) was demonstrated following 4-HC purging. We conclude that properly performed and controlled immunocytochemical staining of bone marrow and peripheral blood cytospins is a sensitive and simple way to detect and quantitate breast cancer cells in hematopoietic specimens harvested for autotransplantation and that CD34-positive progenitor cell selection results in significant reduction in the number of breast cancer cells reinfused with marrow or peripheral blood stem cells.

Antibodies, Monoclonal↗
PubMed1996

Preoperative evaluation of macrophage colony-stimulating factor levels in patients with endometrial cancer.

OBJECTIVE: Our purpose was to examine the relationship between preoperative serum levels of macrophage colony-stimulating factor, alone and in combination with CA 125, and the presence of prognostic clinicopathologic factors and subclinical metastases in women with endometrial cancer. STUDY DESIGN: Ninety-two women who underwent primary exploration for endometrial adenocarcinoma had preoperative serum samples evaluated for macrophage colony-stimulating factor and CA 125 levels. Multivariate analysis was used to determine the associations of surgicopathologic findings with macrophage colony-stimulating factor and CA 125 levels. Logistic regression analysis was used to identify factors associated with the risk of extrauterine disease. The association of macrophage colony-stimulating factor and CA 125 levels with stage, grade, and depth of myometrial invasion and histologic characteristics were analyzed with Fisher's two-tailed exact test. RESULTS: Elevated levels of macrophage colony-stimulating factor were not associated with depth of myometrial invasion, histologic grade, or histologic cell type; however, advanced stage (p = 0.02) and the presence of lymph node metastases (p = 0.04) were associated with elevated levels. Sensitivity and specificity of macrophage colony-stimulating factor for predicting extrauterine disease were 42% and 89%, respectively. If either an elevated macrophage colony-stimulating factor or an elevated CA 125 level was used to predict extrauterine disease, the sensitivity was increased to 67% but the specificity was decreased to 78%. Macrophage colony-stimulating factor elevations predicted lymph node metastases with a sensitivity of 50% and a specificity of 86%. A multivariate regression model showed CA 125 to be the most significant predictor of extrauterine disease; macrophage colony-stimulating factor also contributed prognostic information (p = 0.02). The sensitivity and specificity of the multivariate model for predicting extrauterine disease were 75% and 73%, respectively. CONCLUSION: Macrophage colony-stimulating factor and CA 125 are neither sensitive nor specific enough to be used as predictors of the presence or absence of extrauterine disease in patients with endometrial cancer.

Adenocarcinoma↗
PubMed1996

Expression of the 67-kD laminin receptor, galectin-1, and galectin-3 in advanced human uterine adenocarcinoma.

Alterations of tumor cell interactions with laminin, a basement membrane glycoprotein, are consistent features of the invasive and metastatic phenotype. Qualitative and quantitative changes in the expression of cell surface laminin-binding proteins have been correlated with the ability of cancer cells to cross basement membranes during the metastatic cascade. Such phenotypic modifications are usually associated with poor prognosis. In this study, the authors examined the possibility that expression of three laminin-binding proteins, the 67-kD laminin receptor (67LR), galectin-1, and galectin-3, is altered in human endometrial cancer in a fashion similar to that reported in other carcinomas, such as breast, colon, and ovarian cancer. Twenty advanced uterine adenocarcinomas were analyzed for expression of these three molecules using immunoperoxidase staining and specific antibodies. The authors found a significant increase in the expression of the 67LR and galectin-1 in cancer cells compared with normal adjacent endometrium (P = .0004 and .0022, respectively). As observed in other carcinomas, a significant down-regulation of galectin-3 expression was found in endometrial cancer cells compared with normal mucosa (P = .02). In the galectin-3 positive tumors, galectin-3 was detected in the cytoplasm and/or nucleus of cancer cells. Interestingly, tumors in which galectin-3 was detected only in the cytoplasm were characterized by deeper invasion of the myometrium than lesions where galectin-3 was found both in nucleus and cytoplasm (P = .02). This study shows an alteration of nonintegrin laminin-binding protein expression in advanced human endometrial cancer. Further studies on larger populations should determine the prognostic value of the detection of these laminin-binding proteins in endometrial carcinoma. Inverse modulation of the 67LR and galectin-3 appears to be a phenotypical feature of invasive carcinoma.

Adenocarcinoma↗
PubMed1996

A comparison of immunohistochemistry, two-color immunofluorescence, and flow cytometry with cell sorting for the detection of micrometastatic breast cancer in the bone marrow.

A significant percentage of women with primary breast cancer have micrometastatic disease in the bone marrow. Bone marrow involvement may be an adverse prognostic factor, and more aggressive therapy may be indicated for these patients. There are a number of different techniques and antibodies used to detect tumor cells in the bone marrow. We used the same panels of four antibreast cancer antibodies and compared three immunodetection techniques: two-color immunofluorescence, immunohistochemical staining, and fluorescence-activated cell sorting with cytologic examination of the sorted cells. The two-color immunofluorescence technique was superior and consistently detected one tumor cell contaminating one million normal bone marrow cells and had no reactivity with normal bone marrow.

Bone Marrow Neoplasms↗
PubMed1996

Specificity and affinity of 26 monoclonal antibodies against the CA 125 antigen: first report from the ISOBM TD-1 workshop. International Society for Oncodevelopmental Biology and Medicine.

The specificity of 26 monoclonal antibodies against the CA 125 antigen was investigated in two phases of the ISOBM TD-1 workshop. The binding specificity was studied using CA 125 immunoextracted by specific antibodies immobilized on various solid phases, or on the surface of human cell lines. Immunometric assays using all possible antibody combinations were used to study the topography of antibody binding sites on the antigen. We conclude that the CA 125 antigen carries only two major antigenic domains, which classifies the antibodies as OC125-like (group A) or M11-like (group B). One antibody, OV 197, showed binding specificity related to some of the OC125-like antibodies, but was classified into a separate group C. The OC125-like group of antibodies has four subgroups with different binding specificities. These are A1 = OC 125 and K 95, A2 = K 93, A3 = B43.13, and A4 = ZS 33, B27.1 and CCD 247. Binding of nonlabelled OC 125 or K 95 to CA 125 caused a marked increase in binding of labelled OV 197 to the complex. This conformational change was not observed with any other antibody combinations. Antibody B43.13 could form immunometric assay combinations particularly with antibodies of subgroup A4, indicating that the B43.13 epitope is in the periphery of the binding area of OC125-like antibodies. The M11-like group of antibodies is more homogenous with strong cross-inhibition between most antibodies. Only one antibody, ZR 38, would form an immunoassay combination with other M11-like antibodies and thus represents a distinct subgroup. The main group of M11-like antibodies are M 11, ZR 45, MA602-6, K 91, OV 185, K 101, K 90, K 96, K 97, K 102, CCD 242, 145-9, and 130-22. Antibody OV 197 binds to a domain designated C and is unique, as stated above. Antibody pairs from any two of the three groups may be used in immunometric assays. Three antibodies were not studied by complete cross-inhibition due to low affinity (OV 198 and K 100) or lack of material (MA602-1). OV 198 and K 100 are most likely OC125-like and MA602-1 is M11-like. Antibody affinity was estimated with labelled antigen in solution or with antigen absorbed on microtiter wells. Western blot analysis showed staining both in the stacking gel and corresponding to a molecule of 200 kDa. There was a marked difference between the antibodies in their ability to bind to CA 125 immobilized on a membrane. Strongest binding was observed with the M11-like antibodies, particularly M 11, K 96, K 97, MA602-6, 145-9. Antibodies belonging to the subgroup A4 were the only OC 125-like antibodies which reacted well with CA 125 in Western analysis. Digestion of CA 125 with proteolytic enzymes showed it to be particularly sensitive to trypsin cleavage. However, no low molecular weight fragments with preserved immunoreactivity were found.

Animals↗
PubMed1996

Expression of alpha 6 and beta 4 integrins in serous ovarian carcinoma correlates with expression of the basement membrane protein laminin.

The surface of a normal ovary is covered by a monolayer of epithelial cells that rest on a basement membrane. The glycoprotein laminin is the major noncollagenous protein present in the basement membrane. The integrins alpha 1 beta 1, alpha 2 beta 1, alpha 3 beta 1, alpha 6 beta 1, and alpha 6 beta 4 serve as cell surface receptors for laminin. During the progression of serous ovarian carcinoma, tumor cells are frequently exfoliated from the surface of the ovary, thereby losing contact with the basement membrane. This study was designed to determine whether alterations in integrin expression may be associated with the malignant phenotype of the primary ovarian tumor and exfoliated ovarian carcinoma cells in the ascites fluid. By immunohistochemical staining, the entire surface of epithelial cells of normal ovaries stained positively for beta 1, alpha 2, and alpha 3 integrins, whereas only the basal surface of the epithelial cells, where they are in contact with laminin, stained positively for alpha 6 and beta 4. The entire surface of epithelial cells of solid tumors from patients with serous ovarian carcinoma stained positively for beta 1, alpha 2, and alpha 3 integrins. In most cases, no intact basement membrane surrounded the tumor nests, and staining for alpha 6 and beta 4 was irregular. When present, the basement membrane stained positively for laminin, and the basal surface of the epithelial cells stained positively for alpha 6 and beta 4. Ovarian carcinoma ascites cells exhibited a distinct phenotype, with a significant decrease in expression of the alpha 6 and beta 4 integrin subunits. As alpha 6 and beta 4 integrin subunits are present at the basal surface of many epithelial cells and serve as receptors for laminin, it is possible that ovarian carcinoma epithelial cells may be released from the basement membrane of the ovary due to their deficit of alpha 6 and beta 4 integrin subunits.

Adult↗
PubMed1996

Immunohistochemical characterization of 22 monoclonal antibodies against the CA125 antigen: 2nd report from the ISOBM TD-1 Workshop.

We evaluated the immunohistological (IH) characteristics of 22 different antibodies that were submitted for study in the frame of the TD-1 ISOBM Workshop on monoclonal antibodies against CA125. Information on relative affinities and epitope similarities was obtained from a parallel immunochemical study. Antibodies were tested at concentrations of 10 and 1 micrograms/ml on frozen and paraffin sections. Paraffin sections were stained according to the streptavidin-biotin complex protocol, and frozen sections according to a two-step immunoperoxidase technique. Aminoethylcarbazole served as the chromogen. The tissues were from normal proliferative endometrium (formalin-fixed paraffin-embedded) material and clear-cell adenocarcinoma of the ovary (formalin-fixed paraffin-embedded and frozen material). Sections were scored for staining in epithelial cells, basal, apical and diffuse cytoplasmic and in stromal components. Intensity was graded as 1, 2 or 3 for epithelial cells and as -1, -2 or -3 for stroma. The cumulative scores for each antibody expressed the discriminative properties of specific epithelial staining against background. M11 and M11-like antibodies, as well as OC125 and OC125-like antibodies, in general showed good staining results. Although there was a trend for high-affinity antibodies to show higher scores, there was no clear relationship between affinity and staining result. For nine antibodies (ZR45, MA602-1, K102, K94, K90, OV185, K97, K96, OV198), the reactions in paraffin and frozen sections were of similar intensity. Most of these were of low affinity with one exception: antibody ZR45, a rat monoclonal antibody (MAb) which had a high relative affinity. For eight antibodies (M11, K101, MA602-6, ZS33, B27.1, B43.13, K93, OC125), a loss of specific staining was observed in frozen sections. All but two of these antibodies (MA602-6 and OC125) were of high relative affinity. With four antibodies (K91, ZR38, K95, K100), the reverse situation was observed. One (K100) was of low affinity, two (K95 and K91) of high affinity and the fourth (ZR38) was a rat MAb of high affinity. Mainly due to the increased cytoplasmic staining in carcinoma, the reactivity in paraffin sections was less extensive in normal endometrium compared to ovarian carcinoma for the majority of antibodies, irrespective of their affinity or epitope group. The IH characterization of these antibodies may be of help in selecting antibodies with specific properties for further comparative studies. The reactivity of normal endometrium with all useful antibodies makes it a good candidate for standard external IH tissue control.

Adenocarcinoma, Clear Cell↗