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J C Byrd

Publications and source records attributed to J C Byrd.

At least 73 records · Page 4Linked to original sources
PubMed1998

An insulin-like growth factor II (IGF-II) affinity-enhancing domain localized within extracytoplasmic repeat 13 of the IGF-II/mannose 6-phosphate receptor.

Insulin-like growth factor II (IGF-II) and phosphomannosylated glycoproteins bind to distinct sites on the same receptor, the IGF-II/mannose 6-phosphate receptor (IGF2R). Analysis of truncated receptors (minireceptors) has been used to map the IGF-II binding site within the receptor's extracytoplasmic domain, which consists of 15 homologous repeats. A minireceptor consisting of repeat 11 contained the minimal elements for binding IGF-II, but with 5- to 10-fold lower relative binding affinity than the full-length receptor. We hypothesized that the complete, high-affinity IGF-II binding site is formed by interaction between the primary site in repeat 11 and a putative affinity-enhancing domain. To determine the minimum portion of the IGF2R's extracytoplasmic domain needed for expression of high-affinity IGF-II binding, a nested set of FLAG epitope-tagged minireceptors encompassing repeats 11 through 15 was prepared and transiently expressed in 293T cells. Minireceptors containing repeats 11-13 or 11-15 exhibited high affinity, comparable to the full-length receptor (IC50 = 1-2 nM), whereas constructs containing repeat 11 only or repeats 11-12 did not (IC50 = 10-20 nM). These data suggested that the affinity-enhancing domain is located within repeat 13, which contains a unique 43-residue insert that has approximately 50% sequence identity to the type II repeat of fibronectin. Although a repeat 13 minireceptor did not bind IGF-II on its own, an 11-13 minireceptor containing a deletion of the 43-residue insert exhibited low IGF-II binding affinity (IC50 = 10-20 nM). Expression of mutant receptors from a full-length IGF2R construct bearing a deletion of the 43-residue insert was very low relative to wild type. Depletion assays using IGF-II-Sepharose showed that the mutant receptor had lower affinity for IGF-II than the wild-type receptor. This study reveals that two independent receptor domains are involved in the formation of a high-affinity binding site for IGF-II, and that a complete repeat 13 is required for high-affinity IGF-II binding.

Binding Sites↗
PubMed1998

Old and new therapies in chronic lymphocytic leukemia: now is the time for a reassessment of therapeutic goals.

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia for which therapeutic options remain unsatisfying as cure has remained elusive. Recent laboratory discoveries and promising results from completed phase III studies with fludarabine provide reason to reassess therapeutic goals in the treatment of patients with symptomatic CLL. Early enrollment of patients on protocols using combination therapies with fludarabine and new agents such as flavopiridol, IDEC-C2B8, Campath-1H, UCN-01, bryostatin, FR 901228, and melarsoprol will hopefully represent the next advance to improved overall survival and ultimately the cure of CLL.

Alkaloids↗
PubMed1998

Mixed-type autoimmune hemolytic anemia following fludarabine treatment in a patient with chronic lymphocytic leukemia/small cell lymphoma.

BACKGROUND AND OBJECTIVES: Mixed-type autoimmune hemolytic anemia (AIHA) is a rare complication of chronic lymphocytic leukemia (CLL). We report a patient with small lymphocytic lymphoma (phenotypic CLL) who developed symptomatic anemia 3 weeks after her fifth cycle of fludarabine, a T cell immunosuppressant. MATERIALS AND METHODS: An antibody screen and panel, direct antiglobulin test, rapid acid eluate, rabbit erythrocyte stroma (RESt) adsorption, and autoadsorption were performed. RESULTS: Warm and cold autoantibodies were detected. prompt treatment with corticosteroids and minimal blood transfusions led to marked improvement. CONCLUSION: Normally, T cells suppress polyclonal lymphocytes that produce autoantibodies. Suppression of T cells in this patient, in addition to the underlying disease process, may explain this mixed-type AIHA, the first reported case to occur following fludarabine treatment.

Anemia, Hemolytic, Autoimmune↗
PubMed1998

Patients with isolated trisomy 8 in acute myeloid leukemia are not cured with cytarabine-based chemotherapy: results from Cancer and Leukemia Group B 8461.

To date, neither the clinical significance of isolated trisomy 8, the most frequent trisomy in acute myeloid leukemia (AML), nor the effect of age within a single cytogenetic group has been examined. We report a large cohort of adult trisomy 8 patients and examine whether increasing age within a homogeneous cytogenetic group alters clinical outcome. Characteristics and outcome of patients with isolated trisomy 8 enrolled in the prospective Cancer and Leukemia Group B (CALGB) cytogenetic study CALGB 8461 are described. Isolated trisomy 8 was identified in 42 (3.03%) of 1387 patients enrolled in five CALGB treatment protocols. These patients had a median age of 64 (range, 16-79) years, 50% female proportion, and a low frequency of hepatomegaly (10%) or splenomegaly (10%). Laboratory features included a median white blood count of 7.3 x 10(9)/L, nonspecific French-American-British distribution, with 36% of patients having Auer rods. Treatment outcome was unsatisfactory with a complete remission (CR) rate of 59%, median CR duration of 13.6 months, and median survival of 13.1 months. Older age adversely affected outcome; trisomy 8 patients > or =60 years had both an inferior CR rate (40% versus 88%; P = 0.004) and overall survival (median, 4.8 versus 17.5 months; P = 0.01), as compared with those <60 years of age. Of the patients <60 years of age, only four remain alive, and all received noncytarabine-based intensive chemotherapy, followed in three cases by autologous (n = 2) or allogeneic (n = 1) stem cell transplant in CR1. Adults with AML and isolated trisomy 8 have a poor outcome that is accentuated by increasing age and is rarely cured with cytarabine-based therapy. Alternative investigational treatments should be considered for individuals with this AML subset.

Acute Disease↗
PubMed1997

Sulfated lewis X determinants as a major structural motif in glycans from LS174T-HM7 human colon carcinoma mucin.

This article describes oligosaccharide structures of mucin isolated from nude mouse xenograft tumors produced by LS174T-HM7 cells, a subline of the human colon carcinoma LS174T with higher metastatic tendency and higher mucin production. A striking feature of the oligosaccharides of the LS174T-HM7 xenograft tumor mucin was a predominance of sulfated Lewis X determinants: HSO3-Galbeta1-4(Fucalpha1-3)GlcNAc. In addition to one previously known saccharide with one sulfated Lewis X determinant, the HM7 xenograft tumor mucin contained multiple novel structures containing one, two, or three sulfated Lewis X determinants. This determinant, known to act as a selectin ligand, has been found previously in minor saccharide components of human milk as well as mucins, but never before as a predominant structure in one mucin source.

Animals↗
PubMed1997

Expression of the endogenous galactose-binding protein galectin-3 correlates with the malignant potential of tumors in the central nervous system.

BACKGROUND: The 31-kilodalton beta-galactoside-binding protein galectin-3 has been associated with cellular transformation and metastasis. Because neural tissues contain large amounts of glycoconjugates, and endogenous carbohydrate-binding proteins have been described in the human brain, the authors examined the expression of galectin-3 in human brain tumors and metastases to the central nervous system. METHODS: Brain tumors were categorized by the World Health Organization system and galectin-3 expression by immunoperoxidase staining using a quantitative staining score. RESULTS: Glioblastomas (Grade 4 astrocytomas) all stained strongly for galectin-3, whereas low grade astrocytomas (Grade 2) did not express the endogenous lectin. Anaplastic astrocytomas (Grade 3) exhibited intermediate expression. The staining score was significantly associated with tumor grade (P < 0.001). Normal brain tissue and benign tumors did not express galectin-3, whereas metastases to the brain were all positive for galectin-3 expression. Metastases expressed significantly more galectin-3 than the primary tumors from which they were derived (P = 0.003). CONCLUSIONS: Galectin-3 expression correlates with the malignant potential of tumors in the central nervous system.

Antigens, Differentiation↗
PubMed1997

Expression of the neural cell adhesion molecule CD56 is associated with short remission duration and survival in acute myeloid leukemia with t(8;21)(q22;q22).

Although acute myeloid leukemia (AML) with t(8;21) (q22;q22) is associated with a high complete remission (CR) rate and prolonged disease-free survival, treatment outcome is not universally favorable. Identifying factors that predict for treatment outcome might allow therapy to be optimized based on risk. AML with t(8;21) has a distinctive immunophenotype, characterized by expression of the myeloid and stem cell antigens CD13, CD15, CD34, and HLADr, and frequent expression of the B-cell antigen CD19 and the neural cell adhesion molecule CD56, a natural killer cell/stem cell antigen. Because CD56 expression has been associated with both extramedullary leukemia and multidrug resistance, we sought to correlate CD56 expression with treatment outcome in AML with t(8;21). Pretreatment leukemia cells from 29 adult de novo AML patients with t(8;21) treated on Cancer and Leukemia Group B (CALGB) protocols were immunophenotyped by multiparameter flow cytometry as part of a prospective immunophenotyping study of adult AML (CALGB 8361). CD56 was expressed in 16 cases (55%). There was no correlation between CD56 expression and age, sex, white blood cell count, granulocyte count, the presence of additional cytogenetic abnormalities, or the presence of extramedullary disease at diagnosis. The CR rate to standard-dose cytarabine and daunorubicin was similar for cases with and without CD56 expression (88% v 92%; P = 1.0). Post-CR therapy included at least one course of high-dose cytarabine in 24 of 26 patients who achieved CR; numbers of courses administered were similar in cases with and without CD56 expression. Although post-CR therapy did not differ, CR duration was significantly shorter in cases with CD56 expression compared with those without (median, 8.7 months v not reached; P = .01), as was survival (median, 16.5 months v not reached; P = .008). We conclude that CD56 expression in AML with t(8;21) is associated with significantly shorter CR duration and survival. Our results suggest that CD56 expression may be useful in stratifying therapy for this subtype of AML.

Acute Disease↗
PubMed1997

Leukemic thyroiditis as the initial relapsing sign in a patient with acute lymphocytic leukemia and blast expression of the neural cell adhesion molecule.

We report a patient with a history of T-cell ALL in remission who presented with symptoms and laboratory values consistent with subacute thyroiditis but was found to have leukemic thyroiditis as the first clinical manifestation of leukemic relapse. Bone marrow examination at this time demonstrated recurrent ALL. After successful re-induction with chemotherapy and an allogeneic bone marrow transplant this patient developed an isolated recurrence of her ALL manifested by symptomatic thyromegaly and a new mediastinal mass that was treated with irradiation. Despite no medullary recurrence of ALL, the patient developed pleuritic chest pain and shortness of breath and succumbed to pericardial extramedullary leukemia 9 months later. This to our knowledge is the third reported case of symptomatic ALL involvement of the thyroid gland and the first to be confirmed histologically. Furthermore, this patient had blast expression of the neural cell adhesion molecule (CD56), a cell surface marker that has not been studied in ALL but has previously been identified as a risk factor for extramedullary leukemia (EML) in acute non-lymphocytic leukemia. The authors hypothesize that CD56 expression in this patient might have contributed to her predisposition to EML.

Adult↗
PubMed1997

Aberrant expression of gland-type gastric mucin in the surface epithelium of Helicobacter pylori-infected patients.

BACKGROUND & AIMS: Helicobacter pylori is found within the gastric mucous gel layer and in association with the epithelial surface. The aim of this study was to determine the effect of H. pylori infection on mucin gene expression (MUC6, MUC5, and MUC1) in the gastric epithelium. METHODS: Gastric biopsy specimens were examined by immunohistochemistry and in situ hybridization for mucin gene expression. RESULTS: MUC6 was limited to mucous glands of H. pylori-negative patients, but 72% of H. pylori-positive patients also expressed MUC6 in surface mucous cells. In contrast, MUC5 mucin was found in significantly fewer surface mucous cells of H. pylori-positive specimens. Carbohydrates recognized by Lewis (Le) X and paradoxical concanavalin A (con A) staining were aberrantly expressed in the surface mucous cells of 16 of 27 and 17 of 23 H. pylori-positive tissues, respectively. Surface Le(b) was present in 26 of 27 H. pylori-positive and 19 of 30 H. pylori-negative tissues. Eradication of H. pylori resulted in reversal of surface MUC5 and MUC6 expression toward normal patterns. Purified gastric mucins of H. pylori-positive patients bound more anti-MUC6 and anti-Le(b) than mucins from H. pylori-negative patients. CONCLUSIONS: The type of mucin that is normally limited to mucous glands is aberrantly expressed in surface mucous cells of H. pylori-positive patients, whereas less of the surface epithelium expresses normal surface-type gastric mucin.

Adult↗
PubMed1997

Extramedullary leukemia adversely affects hematologic complete remission rate and overall survival in patients with t(8;21)(q22;q22): results from Cancer and Leukemia Group B 8461.

PURPOSE: To examine the prognostic significance of extramedullary leukemia (EML) at presentation in patients with t(8;21)(q22;q22) karyotype. PATIENTS AND METHODS: Consecutive patients with t(8;21) treated on Cancer and Leukemia Group B de novo acute myeloid leukemia (AML) treatment studies were examined for the presence of EML (granulocytic sarcoma, subcutaneous nodules, leukemia cutis, or meningeal leukemia) at initial presentation. Clinical features and outcome of t(8;21) patients with and without EML were compared. RESULTS: Of 84 patients with t(8;21), eight (9.5%) had EML manifesting as granulocytic sarcoma (five paraspinal, one breast, and one subcutaneous) or symptomatic meningeal leukemia (n = 1). The pretreatment prognostic variables of t(8;21) patients with and without EML were similar. The hematologic complete remission (CR) rate for t(8;21) patients with EML was 50% versus 92% for those without EML (P=.006). The median CR duration for EML patients was 14.7 months. Patients with EML had a shorter survival (P = 0.002, median 5.4 months versus 59.5 months). This poor outcome may relate to inadequate local (radiation or intrathecal) therapy for patients with spinal or meningeal EML, resulting in residual/recurrent EML following induction chemotherapy (n = 2) or at relapse (n = 1) and permanent neurologic deficits (n = 4). Only one of the EML patients received high-dose cytarabine (HDAC) intensification; this is the only EML patient remaining alive in CR. CONCLUSION: Patients with t(8;21) and EML have a low CR rate and overall survival. An aggressive local and systemic induction therapy should be considered for this patient subset. The effectiveness of HDAC intensification in t(8;21) patients with EML is uncertain and warrants further study.

Adult↗
PubMed1997

Detection of Epstein-Barr virus in transformations of low-grade B-cell lymphomas after fludarabine treatment.

Fludarabine is a highly effective chemotherapeutic agent for chronic lymphocytic leukemia/small lymphocytic lymphoma and is also active in other B-cell lymphoproliferative disorders. Although highly efficacious in destroying the malignant B-cells, fludarabine also causes T-cell lymphopenia and immunosuppression. We present five patients given fludarabine for low-grade B-cell lymphoproliferative disorders who showed transformation of the primary neoplasm to a higher grade tumor. Immunohistologic antibody studies were performed on paraffin-embedded tissue sections of the initial tissue (when available) and on the follow-up biopsy specimens for CD20, CD3, CD45RO, CD43, CD30, CD15, and latent membrane protein (LMP-1) for Epstein-Barr virus (EBV). The initial diagnoses in these five patients included chronic lymphocytic leukemia/small lymphocytic lymphoma (three cases), follicle center lymphoma (one case), and Waldenstrom's macroglobulinemia (one case). All of the follow-up biopsy specimens showed scattered Hodgkin's-like cells, and two of the five also showed foci of large-cell transformation. The Hodgkin's-like cells showed CD30 immunoreactivity in four of the five cases and CD15 immunoreactivity in three of the five. Strong immunoreactivity of the large, atypical, Hodgkin's-like cells for LMP-1 of EBV was noted in four cases; in the remaining case, this finding was equivocal. In situ hybridization for EBV-encoded RNA was positive in four of the five cases. Molecular studies by polymerase chain reaction (PCR) showed the presence of EBV in three of the five cases. PCR for detection of immunoglobulin heavy chain demonstrated identical monoclonal rearrangements in the original lymphoma and transformation in one case with available material. The CD4 lymphocyte count in each patient was less than 550/microL, indicating cellular dysfunction. Transformation of low-grade non-Hodgkin's lymphomas after fludarabine therapy might be associated with EBV and severe immunosuppression.

Adult↗
PubMed1996

Colon cancer mucin: a new ligand for the beta-galactoside-binding protein galectin-3.

Galectin-3, an endogenous beta-galactoside-binding lectin, is present on colon cancer cells and may play a role in metastasis. Galectin-3 binds poly-N-acetyllactosamine structures on glycoproteins, but its natural ligands remain to be fully defined. Galectin-3 bound to purified native and desialylated colon cancer mucin in a concentration-dependent manner, which was completely inhibited by 0.1 M lactose, the competitive inhibitory sugar for this protein. Mucin purified from highly metastatic LS-Lim6 human colon cancer cells bound galectin-3 to a 2-fold greater extent than mucin from low-metastatic parental cell line LS174T. Desialylation increased binding to mucin >4-fold. Mucin purified from LS-B colon cancer cells is fully glycosylated and bound >40-fold more galectin-3 than mucin purified from clonal cell line LS-C, which produces mucin lacking peripheral carbohydrate structures. Endogenous galectin-3 was detected by Western analysis in all cell lines, and its expression was related to mucin production and metastatic capacity. When serum from a patient with metastatic colorectal cancer was chromatographed on Superose 6, >70% of galectin-3 ligand was identified as circulating mucin. Colon cancer mucin is a newly identified ligand for galectin-3, and binding of galectin-3 to mucins depends on peripheral carbohydrate structures. Binding of this endogenous lectin to mucins; may influence cellular interactions that play a role in colon cancer metastasis.

Adenocarcinoma↗
PubMed1996

Renal medullary carcinoma: clinical and therapeutic aspects of a newly described tumor.

BACKGROUND: Renal medullary carcinoma is a newly described, aggressive kidney tumor. All patients with the disease have been African-American with sickle cell (SC) trait or hemoglobin SC disease. METHODS: Patient information was obtained from individual patient records and from the Department of Defense national data bank, The Defense Enrollment and Eligibility Reporting System. Data were obtained from either personal review of the patient's records or from discussion with the patient's physician. Cytogenetic studies were performed on one patient. RESULTS: Six patients are presented. All had SC trait. Median age was 24.5 years and 1 patient was female. Time from diagnosis to death averaged 3 months (range 1-7 mos). No objective responses were reported to a wide variety of chemo and immunotherapies: cyclophosphamide, doxorubicin, cisplatin; methotrexate, vinblastine, doxorubicin, and cisplatin; single agent interferon; single agent paclitaxel; or single agent vinblastine. Investigational regimens included topotecan, doxorubicin, and filgrastim; alpha-interferon, interleukin-2, and 5-fluorouracil; and single agent paclitaxel. Cytogenetic studies revealed numerous structural, as well as numerical anomalies. Of the cells successfully karyotyped (n=4), 2 contained abnormalities of chromosome 3 and all contained monosomy 11. CONCLUSIONS: Renal medullary carcinoma is an aggressive, chemoresistant tumor. Time from discovery of tumor to patient death is very short and has been altered by a wide variety of chemotherapies and immunotherapies. An unidentified genetic component is likely present.

Adult↗
PubMed1996

Acute pancreatitis associated with continuous infusion cytarabine therapy: a case report.

BACKGROUND: While acute pancreatitis is a recognized complication of numerous drugs, cytarabine's role in causing this complication is controversial. Approximately 15 cases have been reported to the Food and Drug Administration linking cytarabine with pancreas-related toxicities. Previous case reports have been complicated by comorbid illnesses and the coadministration of other drugs associated with acute pancreatitis. METHODS: This report describes the clinical course of a patient with acute myelogenous leukemia (AML) who developed recurrent pancreatitis associated with cytarabine therapy. RESULTS: A male age 36 years with French-American-British M5B acute myelogenous leukemia received induction cytarabine (200 mg/m2/day) by continuous infusion for 7 days, and subsequently developed acute pancreatitis. The patient was rechallenged with intermittent, bolus, high dose cytarabine (HDAC) (3 g/m2bid administered over 3 hours) during the following intensification treatment, but did not develop clinical acute pancreatitis. Retreatment with continuous infusion cytarabine at a later time resulted in recurrence of acute pancreatitis. CONCLUSIONS: This case illustrates that cytarabine treatment may cause acute pancreatitis, and that this toxicity may be schedule dependent. In those with known sensitivity to cytarabine, altering the administration technique may avoid this complication.

Acute Disease↗
PubMed1996

Anaphylactoid reactions to methotrexate.

BACKGROUND: Methotrexate is a chemotherapeutic agent frequently utilized for the treatment of malignant, rheumatic, and pulmonary diseases. Although this agent has been extensively used for more than 45 years, there are few reports of immediate systemic hypersensitivity reactions. The reported immediate reactions include anaphylaxis, urticaria, and hepatitis. However, these reactions have been reported to occur only after some prior exposure to methotrexate. No immediate hypersensitivity reactions to methotrexate have been reported during the initial exposure. We describe two patients who developed immediate systemic hypersensitivity reactions during the initial administration of methotrexate. METHODS: The clinical outcomes of two patients treated by the Hematology/Oncology department at a tertiary care military medical center are described. The National Library of Medicine in Bethesda, Maryland, was electronically searched for the literature review. RESULTS: Patient 1, a 30-year-old male with localized high grade osteosarcoma of the left distal femur, developed generalized pruritus, urticaria, angioedema, and pharyngeal edema within 10 minutes of receiving the initial administration of intravenous high-dose methotrexate. No other pharmaceutical agents, such as antiemetics, were found to cause symptoms on rechallenge. The severity of this reaction precluded continuation of methotrexate therapy. Patient 2, a 23-year-old male with localized high grade osteosarcoma of the right distal tibia, developed pruritus and urticaria within 30 minutes of receiving the initial administration of intravenous high dose methotrexate. This patient, like most patients with immediate hypersensitivity reactions to methotrexate, developed recurrent symptoms during rechallenge of this agent despite prophylactic premedication. CONCLUSIONS: Unlike prior reports in our literature, our cases demonstrate that anaphylactoid reactions can occur during the initial exposure to methotrexate. Clinicians must be prepared to treat potentially life-threatening reactions with both the initial and subsequent doses of methotrexate.

Adult↗
PubMed1996

Physician extenders for cost-effective management of hypercholesterolemia.

OBJECTIVE: Treatment of elevated cholesterol levels reduces morbidity and mortality from coronary heart disease in high-risk patients, but can be costly. The purpose of this study was to determine whether physician extenders emphasizing diet modification and, when necessary, effective and inexpensive drug algorithms can provide more cost-effective therapy than conventional care. DESIGN: Randomized controlled trial. SETTING: A Department of Veterans Affairs Medical Center. PATIENTS: Two hundred forty-seven veterans with type IIa hypercholesterolemia. INTERVENTIONS: Patients assigned to either a cholesterol treatment program (CTP) or usual health care provided by general internists (UHC). CTP included intensive dietary therapy administered by a registered dietitian utilizing individual and group counseling and drug therapy initiated by physician extenders for those failing to achieve goal low-density lipoprotein (LDL) levels with diet alone. A drug selection algorithm for CTP subjects utilized niacin as initial therapy followed by bile acid sequestrants and lovastatin. Subjects were followed prospectively for 2 years. MEASUREMENTS: Primary outcome measurements were effectiveness of therapy defined as reductions in LDL cholesterol (LDL-C), and whether goal LDL-C levels were achieved; costs of therapy; and cost-effectiveness defined as the cost per unit reduction in the LDL-C. MAIN RESULTS: Total program costs were higher for CTP patients than for UHC patients ($659 +/- $43 vs $477 +/- $42 per patient, p < .001). However, at 24 months the patients in CTP were more likely to achieve LDL goal levels (65% vs 44%, p < .005), and also achieved greater reductions in LDL-C 27% +/- 2% vs 14% +/- 2% at 24 months, p < .001). Program costs per unit (mmol/L) reduction in the LDL-C, a measure of cost-effectiveness, was significantly lower for CTP ($758 +/- $58 vs $1,058 +/- $70, p = .002). CONCLUSIONS: Although more expensive than usual care, the greater effectiveness of physician extenders implementing cholesterol treatment algorithms resulted in more cost-effective therapy.

Anticholesteremic Agents↗
PubMed1996

Enhanced sialylation of mucin-associated carbohydrate structures in human colon cancer metastasis.

BACKGROUNDS & AIMS: Patients with mucinous colon cancers often have a poor prognosis. The aim of this study was to determine whether metastatic potential depends on specific alterations in mucin-associated carbohydrate structures. METHODS: A quantitative scoring system was used to examine the expression of mucin-associated carbohydrates in paired human primary colon cancers and metastases and in cecal tumors and liver metastases from an animal model of metastasis. Adhesion of metastatic cells to basement membrane and endothelial ligands was examined. RESULTS: Metastases expressed a decrease in mucin core structures Tn and T, a reciprocal increase in sialyl T and sialyl Tn, and an increase in peripheral sialyl Le(x) compared with the primary tumors from which they arose. Altered expression of sialylated mucin structures resulted from selective metastasis of cells that produce sialomucins. Antibodies to sialylated epitopes or desialylation inhibited adhesion of metastatic cells to basement membranes. Neutralizing antibody to endothelial-associated E-selectin (a ligand for sialyl Le(x)) inhibited adhesion of metastatic cells to cytokine-activated hepatic endothelial cells, and inhibition of sialomucin with antisense to the MUC2 gene inhibited adhesion to E-selectin. CONCLUSIONS: Increased sialylation of mucin-associated carbohydrates is characteristic of colon cancer cells that are most likely to metastasize. Sialylated carbohydrate structures on mucin play a role in adhesive interactions involving both basement membrane and endothelial-associated ligands.

Adenocarcinoma↗