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M A Kuriakose,
W T Chen,
Z M He,
A G Sikora,
P Zhang,
Z Y Zhang,
W L Qiu,
D F Hsu,
C McMunn-Coffran,
S M Brown,
E M Elango,
M D Delacure, F A Chen
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ABSTRACT: We applied a robust combinatorial (multi-test) approach to microarray data to identify genes consistently up- or down-regulated in head and neck squamous cell carcinoma (HNSCC). RNA was extracted from 22 paired samples of HNSCC and normal tissue from the same donors and hybridized to the Affymetrix U95A chip. Forty-two differentially expressed probe sets (representing 38 genes and one expressed sequence tag) satisfied all statistical tests of significance and were selected for further validation. Selected probe sets were validated by hierarchical clustering, multiple probe set concordance, and target-subunit agreement. In addition, real-time PCR analysis of 8 representative (randomly selected from 38) genes performed on both microarray-tested and independently obtained samples correlated well with the microarray data. The genes identified and validated by this method were in comparatively good agreement with other rigorous HNSCC microarray studies. From this study, we conclude that combinatorial analysis of microarray data is a promising technique for identifying differentially expressed genes with few false positives.
Cellular and Molecular Life Sciences CMLS 07/2004; 61(11):1372-83. · 6.57 Impact Factor
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ABSTRACT: To identify the significance of molecular markers in determining the risk of recurrence and distant metastases in nasopharyngeal carcinoma.
In this retrospective case study, we evaluated archival nasopharyngeal carcinoma specimens for patterns of expression of E-cadherin, beta-catenin, c-erb-B2, and Ki-67, which have been demonstrated to be important in other tumors.
Fifty-four cases of nasopharyngeal carcinoma were identified, with a maximum follow-up of 13 years. The histopathological sections were stained using an automated immunohistochemical stainer (NexES, Ventana Medical Systems, Tucson, AZ) for E-cadherin (Zymed Laboratories [San Francisco, CA] and Transduction Laboratories [Lexington, KY] clones), beta-catenin (Zymed), c-erb-B2 (Ventana Medical Systems), and Ki-67 (Novocastra, Burlingame, CA). The numbers of positively staining cells were scored as follows: 0%, 1% to 33%, 34% to 66%, or greater than 67%.
E-cadherin (Zymed) stained positively in only one case. The Transduction Laboratories clone demonstrated a spectrum of staining in all cases, from complete to disrupted to no identifiable membranous staining. The staining was consistently absent at the advancing tumor border, regardless of stage. The loss of beta-catenin expression did not correlate with that of E-cadherin or with clinical outcomes. No staining was identified for c-erb-B2. Ki-67 staining was variable and did not correlate with clinical outcomes.
Altered expression or loss of E-cadherin, or both, may result in loss of function, particularly at the infiltrating edge, with resultant loss of cell polarity, cell migration, and eventual metastasis. The interpretation of E-cadherin staining depends on antibody source. In contrast to recent studies, beta-catenin expression is not altered and c-erb-B2 expression not identified, suggesting that these markers are not important in the prognosis of nasopharyngeal carcinoma.
The Laryngoscope 11/2001; 111(10):1842-6. · 1.75 Impact Factor
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ABSTRACT: Epstein Barr Virus (EBV) associated lymphoproliferative disorders (LPD) express EBV latent antigens that are also expressed on normal B-cells transformed with EBV. This could potentially be exploited to develop immunotherapeutic strategies for LPD and other EBV associated malignancies. To this end we investigated the capacity of human monocyte derived dendritic cells (DC) pulsed with lysate from autologous EBV transformed B-cell lymphoblastoid cell (BCL) lysate to elicit an in vitro antitumor response. BCL lysate pulsed DC generate BCL specific cytotoxic lymphocytes, as lymphocytes primed with such DCs induce cytolysis of autologous (>60%) but not allogeneic BCL (<5%). In addition, lymphocytes primed with BCL lysate pulsed DC secrete gamma-IFN (3176 pg/ml). Whereas gamma-IFN production was markedly reduced (>99%) when BCL specific T-cells were stimulated by BCL lysate pulsed DC in the presence of blocking antibodies to HLA-DR, DP and DQ, use of antibodies to MHC class-I resulted in only a minimal reduction in gamma-IFN production (17%). These studies demonstrate that BCL lysate pulsed DC elicit a predominantly BCL specific, MHC class-Il restricted T cell response. This suggests that vaccination with autologous BCL lysate pulsed DC may represent a viable immunotherapeutic approach for the treatment of LPD.
Journal of experimental & clinical cancer research: CR 07/2001; 20(2):175-82. · 1.50 Impact Factor
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ABSTRACT: To determine the possible functional significance of CD40 expression on human non-small cell lung carcinomas and to assess the potential of CD40 as a therapeutic target, 18 lung tumor cell lines were established from biopsy tissues and were monitored for phenotypic changes on the cell surface and alterations in tumor cell proliferation after the ligation of CD40 with a trimeric fusion protein complex of CD40 ligand (CD40Lt). CD40 cross-linking resulted in up to a 6-fold increase in the surface expression of major histocompatibility complex (MHC) class I, Fas and intracellular adhesion molecule (ICAM)-1 in a subset of tumors expressing the highest levels of CD40. Suppression of tumor proliferation was seen after the ligation of CD40 on CD40Lt-responsive cell lines. The suppression was dose dependent, reversible and resulted from a delay of the tumor cells entering S-phase. No change in the cell phenotype or in proliferation were observed in CD40-negative tumors or in tumors expressing moderate-to-low levels of CD40 after incubation with CD40Lt. CD40-negative tumors transfected with the CD40 gene expressed high levels of CD40 on their surface, but were also unresponsive to CD40Lt cross-linking of CD40. Our data establish that CD40 is required (but not sufficient) for transducing a signal that results in phenotypic changes in human lung tumors and suppression in their proliferation. We conclude that CD40 on non-small cell lung tumors may represent a potential therapeutic target, but only on a subset of the CD40+ tumors.
International Journal of Cancer 06/2001; 92(4):589-99. · 5.44 Impact Factor
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ABSTRACT: Beta1 integrins, expressed on the cell surface of human non-small cell lung carcinomas, are used here as a target for the selective delivery of anti-cancer drug-loaded liposomes. Fab' fragments of a monoclonal antibody specific for human beta1 integrins were conjugated to sterically stabilized liposomes. Confocal microscopy of beta1 integrin-positive lung tumor cells incubated with fluorescently labeled anti-beta1 Fab immunoliposomes revealed a tumor-specific binding and efficient internalization of the liposomes into the tumor cells. The ability of these liposomes to deliver cytotoxic drugs to the tumor and kill these cells was demonstrated in vitro by incubating tumor cells with doxorubicin-loaded anti-beta1 Fab' immunoliposomes. The drug-loaded immunoliposomes were >30-fold more cytotoxic to the tumor cells than drug-loaded liposomes without antibody, nonspecific Fab' control immunoliposomes with drug or immunoliposomes without drug. The therapeutic efficacy of doxorubicin-loaded immunoliposomes was also evaluated in a metastatic human lung tumor xenograft/severe combined immunodeficient (SCID) mouse model. SCID mice that received i.v. injections of human lung tumor cells developed primary tumor nodules in the lung that subsequently metastasized to the liver and adrenal gland. Treatment of SCID mice bearing established lung tumor xenografts with doxorubicin-loaded anti-beta1 Fab immunoliposomes resulted in a significant suppression of tumor growth (monitored periodically by quantifying serum levels of a tumor marker), whereas tumors grew progressively in mice treated with control formulations. In addition to suppressing the growth of the primary lung tumor nodules, the immunoliposomes prevented the metastatic spread of the tumor to the liver and adrenal glands and increased the median survival time of the tumor-bearing mice. We conclude that Fab' immunoliposomes directed to tumor-associated integrins represent a potentially viable approach clinically for the selective delivery of drugs to solid tumors and may be useful in preventing the metastatic spread of lung cancer.
Cancer Research 12/2000; 60(24):6942-9. · 7.86 Impact Factor
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Immunological investigations 06/2000; 29(2):171-6. · 1.16 Impact Factor
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ABSTRACT: The poor prognosis associated with lung cancer is related to the high incidence of regional and distant metastasis. There is a crucial need to identify parameters that can predict a tendancy to metastatic spread to allow better prognostic evaluation and therapeutic approach.
Using flow cytometry we evaluated 18 human lung cancer cell lines for the expression of different surface markers on lung cancers suggested to be possible prognostic parameters, including epidermal growth factor receptor (EGFR), intercellular adhesion molecule 1 (ICAM-1), Fas and CD40.
No correlation was found between tumor prognosis and EGFR, ICAM-1 or Fas. However, a statistically significant correlation was found between the surface expression of CD40 and the metastatic spread of the tumor. In this study, 14 of 18 lung cancer cell lines (78%) expressed CD40 on their surface. All of the 4 tumors that were CD40-negative, were stage I tumors, without any evidence of regional or distant metastasis. Of the 14 tumors that expressed CD40, all but 1 (93%) had either nodal or systemic metastasis at the time of diagnosis. Patients whose tumors were CD40-negative showed a significantly better N stage, overall stage at presentation and survival than those patients with CD40-positive patients. No significant differences between the two groups were observed in tumor size, gender, age, histology, differentiation or preoperative therapy.
These results suggest that CD40 expression on lung cancer may play a role in metastatic spread, and also may serve as a prognostic marker and an indicator of advanced disease.
Cancer Immunology and Immunotherapy 06/2000; 49(2):101-8. · 3.70 Impact Factor
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ABSTRACT: The role of cytokines in tumor regression is now well established. The major limitation for the clinical use of cytokines is the lack of a simple and effective protocol for the local and sustained delivery of cytokines to the tumor milieu. This study reports suppression of human head and neck squamous cell carcinoma (HNSCC) by human peripheral blood lymphocytes (HuPBL) following local, sustained delivery of interleukin-12 (IL-12) to tumors with biodegradable microspheres in a human/SCID mouse chimeric model. Materials and Methods Nondisrupted biopsy pieces (120 mg) of primary HNSCC were implanted s.c. into severe combined immunodeficient (SCID) mice and were expanded by serial passage in mice. Tumors were then titrated with different doses of allogeneic HuPBL by coengraftment of tumor pieces and HuPBL into the subcutis of SCID mice to determine whether the HuPBL possessed antitumor activity (the SCID/Winn model). The lymphocyte subsets that were responsible for the suppression of tumor engraftment were identified by selective depletion of the CD4+, CD8+, and CD56+ cells from the HuPBL prior to engraftment into mice. Attempts were then made to augment the antitumor activity of the HuPBL either by repeated intralesional bolus injections of recombinant human IL-12 (0.5 microg x 10 doses) or with a single dose of IL-12-loaded microspheres ( approximately 1.65 microg IL-12/mg microspheres, 2 mg microspheres/mouse).
Successful engraftment of HNSCC was observed in 12 of 19 different patient samples. Normal histological architecture of tumor was maintained up to four serial passages in the SCID mice. After the first tumor engraftment, but not in subsequent passages, human immunoglobulin produced by plasma cells present in the tumor infiltrating lymphocyte population was detected in the mouse sera. Allogeneic human PBL displayed antitumor cytotoxic activity in a cell dose-dependent fashion when coengrafted with the tumors passaged in SCID mice. Lymphocyte subset depletion studies established that tumor suppression was dependent on both the CD8+ T lymphocytes and the CD56+ natural killer cells. Treatment of tumors with a single intralesional injection of IL-12-loaded microspheres was highly effective, resulting in the complete suppression of tumor engraftment in 50% of the mice. In contrast, treatment of tumors with repeated bolus IL-12 injections suppressed tumor engraftment only transiently and did not result in complete tumor rejection in any of the mice.
The coengraftment of HNSCC and allogeneic lymphocytes into SCID mice provides a viable model with which to evaluate immunotherapeutic strategies for human cancer. The use of biodegradable microspheres for local sustained delivery of cytokines to augment lymphocyte mediated antitumor immunity within the tumor microenvironment provides a safer and simpler alternative to current cytokine immunotherapy protocols.
Head & Neck 02/2000; 22(1):57-63. · 2.40 Impact Factor
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ABSTRACT: A novel biodegradable poly(lactic acid) microsphere formulation was evaluated for in vivo cytokine immunotherapy of cancer in a human tumor xenograft/ severe combined immunodeficiency (SCID) mouse model. Co-injection of interleukin-2 (IL-2)-loaded microspheres with tumor cells into a subcutaneous site resulted in the complete suppression of tumor engraftment in 80% of animals. In contrast, bovine-serum-albumin(BSA)-loaded particles or bolus injections of poly(ethylene glycol)/IL-2 were ineffective in preventing tumor growth. The antitumor effect of IL-2 released by the microspheres was shown to be mediated by the mouse natural killer cells. This is the first evidence that the rejection of human tumor xenografts can be provoked by the sustained in vivo delivery of IL-2 from biodegradable microspheres. The use of poly(lactic acid) microspheres to deliver cytokines to the tumor environment could provide a safer and simpler alternative to gene therapy protocols in the treatment of cancer.
Cancer Immunology and Immunotherapy 03/1998; 46(1):21-4. · 3.70 Impact Factor
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ABSTRACT: Here, it is established that human peripheral blood lymphocytes (HuPBLs), injected s.c. with a human lung tumor into severe combined immunodeficient (SCID) mice, engraft and display antitumor cytotoxic activity. Initial studies used HuPBLs from normal donors and an allogeneic tumor cell line derived from biopsy tissue of a patient with a squamous cell carcinoma of the lung. Evidence of HuPBL antitumor activity was revealed by a cell dose-dependent suppression of the tumor xenograft. Tumor suppression was shown to be dependent upon both CD8+ T cells and CD56+ natural killer cells in the donor HuPBLs. By titrating the antitumor activity of HuPBLs in SCID mice with and without cytokines, it was established that interleukin (IL)-12 enhanced the HuPBL-mediated tumor suppression and that IL-2 had a synergistic effect upon the IL-12 enhancement of cytotoxicity. Subsequent studies revealed that a lung cancer patient's PBLs also suppress the growth of the patient's (autologous) tumor when coinjected s.c. with the tumor cells into SCID mice. The patient's antitumor immunity was shown to be mediated by CD8+ T cells and CD56+ natural killer cells. The data presented here indicate that the s.c. coengraftment of HuPBLs and tumor into SCID mice represents a viable model with which to study (and to periodically monitor) patients' immune responses to their tumors for extended periods of time and suggest that this SCID/Winn assay could be used to evaluate novel immunotherapeutic approaches, such as bolus injections of cytokines, cytokine gene therapy, or vaccination strategies for the treatment of human cancer.
Cancer Research 08/1997; 57(14):2937-42. · 7.86 Impact Factor
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ABSTRACT: Liposomes containing polyethylene glycol-derivatized phospholipids are able to evade the reticuloendothelial system and thereby remain in circulation for prolonged periods. We report here that doxorubicin encapsulated in these sterically stabilized liposomes (S-DOX) suppresses the growth of established human lung tumor xenografts in severe combined immunodeficient (SCID) mice and inhibits the spontaneous metastases of these tumors. The enhanced therapeutic efficacy of S-DOX compared to free doxorubicin was demonstrated in two independent human/mouse models. In the first model, S-DOX inhibited the growth of a human non-small cell lung tumor xenograft established orthotopically in the lungs of SCID mice. Treatment of these mice with S-DOX, but not with free drug, suppressed the growth of the tumor in the lung, prevented metastasis from the lung, and enhanced survival percentage. In another model, the human lung tumor is engrafted into gonadal fat pad of SCID mice. Human tumor xenografts grow floridly in this site of engraftment, and the tumor spreads from this primary site into the peritoneal cavity and subsequently reaches the liver and lung. In this model, free drug suppressed the growth of the primary tumor but had no effect upon the subsequent spread of the tumor into the peritoneal cavity, liver, and lung. In contrast, treatment of the tumor-bearing mice with S-DOX (but not with doxorubicin in conventional liposomes) suppressed the tumor spread to the peritoneal cavity, completely arrested metastasis to the liver and lung, and suppressed the growth of the primary tumor xenograft. This report provides the first evidence that antitumor drugs delivered by sterically stabilized liposomes can arrest the metastasis of human tumor xenografts.
Cancer Research 09/1996; 56(16):3743-6. · 7.86 Impact Factor
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S S Williams, F A Chen,
H Kida,
S Yokata,
K Miya,
M Kato,
M P Barcos,
H Q Wang,
T Alosco,
T Umemoto,
B A Croy,
E A Repasky,
R B Bankert
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ABSTRACT: We report here the placement of nondisrupted 1-mm3 pieces of fresh human lung tumor biopsy tissue into the subcutis of severe combined immunodeficient (SCID) mice results in the engraftment of tumor-infiltrating leukocytes (TIL) in all but 5 of 148 mice inoculated with 39 different biopsy tissue specimens. In mice coengrafted with tumor and TIL the normal histologic architecture of the tumor and TIL interface was maintained for up to 22 wk. The TIL in the xenograft were shown to divide and were maintained exclusively at the site of tumor inoculation. It is established here that plasma cells in the TIL population produce Abs that react in western blots with tumor cell lysates. These Abs were shown to react with high and low m.w. proteins derived from both the membrane and cytosolic fractions of tumor cell lysates. The production of human Ig was found to be T cell dependent, and immunohistochemistry and in situ hybridization of DNA, using a human-specific cDNA probe, established the human identity of the tumor and TIL. High levels of human Ig in the sera of mice inoculated with tumor biopsy tissue are associated with the growth arrest of adenocarcinoma xenografts. Our results establish the co-engraftment of human tumors and TIL into SCID mice as new animal model with which to evaluate TIL function and novel therapeutic strategies that are designed to augment TIL anti-tumor activity.
The Journal of Immunology 04/1996; 156(5):1908-15. · 5.79 Impact Factor
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ABSTRACT: We have used a human/severe combined immunodeficient (SCID) mouse chimeric model (in which human PBLs are engrafted into SCID mice) to investigate in vivo the role of the CD40/CD40 ligand (CD40L) interaction in the generation of humoral immunity by engrafted human cells. It is established in this work that the thymic dependent, multiclonal, humoral immune response of human lymphocytes to mouse erythrocyte protein Ags is inhibited significantly when CD40/CD40L ligation is prevented in vivo. Suppression of the response was observed with administration of neutralizing Abs specific for either CD40 or CD40L, or with the soluble fusion protein human CD40-Fc. Human anti-mouse erythrocyte Abs and the total human Ig levels in the sera of the SCID mice were suppressed for up to 10 wk when the neutralizing agents were administered at the time of human leukocyte engraftment, i.e., coincident with Ag stimulation, and subsequently at 2 and 4 days after Ag stimulation. These results are the first to demonstrate the ability of CD40/CD40L blocking agents to inhibit the human Ag-specific humoral immune response in vivo, and they sustain the notion that these blocking agents may be utilized clinically to eliminate immune responses associated with autoimmunity or allergy. In addition to confirming the importance of the CD40/CD40L interaction of T and B cells in vivo, it is established in this work that the mouse erythrocyte-specific humoral immune response of the lymphocytes in the human PBL/SCID mouse model is a bona fide T cell-dependent response, and that this is a viable model with which to study human lymphocyte activation in vivo. These results also suggest that the costimulatory activation of human B and T cells is not dependent on the microenvironment of the germinal centers.
The Journal of Immunology 10/1995; 155(6):2833-40. · 5.79 Impact Factor
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ABSTRACT: Previously we reported that over 75% of human non-small cell lung cancers overexpress the beta 1 integrin VLA-2 on their surface and show an increase in the mRNA encoding the alpha-2 chain of this integrin. These results suggested the possibility that the overproduction and overexpression of one or more of the beta 1 integrin may be involved in the pathogenesis of human lung tumors by modulating the invasive and/or metastatic potential of the tumor. We report here the generation and characterization of multiple clones of tumor cells derived from the primary culture of cells obtained from biopsy tissue of an aggressive human squamous cell lung tumor. We show that these tumor clones (or clonotypes) exhibit seven different yet stable phenotypes with respect to the expression of five members of the beta 1 integrin family. These results illustrate that a primary human lung tumor consists of multiple subpopulations of cells that while indistinguishable by ultrastructure are heterogeneous with respect to their beta 1 integrins. The availability of these distinct tumor clonotypes derived from a single tumor biopsy have made it possible to test the assumption that the beta 1 integrins play a role in tumor progression. The feasibility of this approach is demonstrated here by the intravenous inoculation of different human tumor clonotypes into severe combined immunodeficient (scid) mice. Our preliminary results with a pair of tumor clonotypes differing in VLA-1 and VLA-2 expression level reveal that the clonotype with high level of VLA-1 and VLA-2 displays a substantial increase in the experimental engraftment and metastasis of the human tumor cells in scid mice.
Cell adhesion and communication 09/1994; 2(4):345-57.
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ABSTRACT: The accurate diagnosis of mesothelioma remains difficult despite advances of diagnostic technique. And specific monoclonal antibody (McAb) against mesothelioma have not been reported. In an attempt to develop mesothelioma specific McAb(s), spleen cells from a mouse immunized with isolated tumor cells were fused to a drug resistant mouse myeloma cell lines. Over 200 hybridomas were assayed for their preferential reactivity with mesothelioma cell lines or mesothelioma tumor biopsy tissues. Two monoclonal antibodies 2A3 and 4E1 were identified that bound 6/7 of the mesotheliomas, tested, but did not bind to the majority, 11/13 (for 2A3) and 12/13 (for 4E1), of other lung tumor types. Based upon western blot analysis of one and two-dimensional gels and upon the distribution pattern of the antibody recognized molecule in mesotheliomas and non-mesothelioma lung tumors, 2A3 binds to the cell adhesion molecule CD44. While the specificity of 4E1 has not yet been unequivocally established it appears to recognize a variant form of the CD44 molecule.
Nippon geka hokan. Archiv für japanische Chirurgie 08/1994; 63(4):129-38.
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ABSTRACT: A single chain glycoprotein with an estimated molecular mass of 160 kD (gp160) was previously identified as a human lung tumor-associated antigen. This tumor marker is shown here to be associated noncovalently with a second 130-kD protein. Sequential immunoprecipitation studies of surface iodinated lung tumor cell lysates reveal that this heterodimeric complex is indistinguishable serologically and structurally from the integrin VLA-2, found originally on activated T lymphocytes and platelets. The VLA-2-like complex expressed on the lung tumors possesses similar characteristic Mg2+ dependent binding of collagen and laminin as observed with VLA-2 on normal cells. RNA analysis indicates that human lung tumors express at least 20 times more VLA-2 alpha chain message than normal adult human lung tissue. The results presented here raise the possibility that the overproduction of VLA-2 may be involved in the pathogenesis of human lung tumors by modulating the invasive and metastatic potential of the tumor.
Journal of Experimental Medicine 06/1991; 173(5):1111-9. · 13.85 Impact Factor
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ABSTRACT: A cell surface glycoprotein (gp160) present on the surface of non-small cell human lung tumors is characterized and compared with the epidermal growth factor receptor (EGFR). The epitope on gp160 recognized by monoclonal antibody 5E8 is shown to be part of the protein moiety of the molecule and is found to be relatively stable. The epitope is stable over a wide pH range and after treatment with urea as well as most ionic and non-ionic detergents. We have observed that gp160 is similar in several respects to the EGFR. However, despite the similarities, several independent lines of experimental evidence presented here suggest that gp160 and the EGFR are distinct molecules. The first evidence suggesting that these two molecules are different is that the EGFR, but not gp160, is constitutively detectable in the A431 cell tissue culture supernatant, and that a pulse of these cells with epidermal growth factor (under conditions which permit the internalization of the receptor-ligand complexes) significantly reduces the expression of the EGFR without noticeably affecting the level of gp160 on the cell surface. Two very different immunofluorescent patterns marking the position of gp160 and EGFR are observed using monoclonal antibodies specific for each molecule. Using an enzyme-linked immunosorbent assay, it was determined that these same monoclonal antibodies do not cross-inhibit one another, and it was established that gp160, but not EGFR, was retained on an affinity column containing anti-gp160 antibodies immobilized to the solid matrix. An additional finding that supports the notion that gp160 and the EGFR are distinct molecules is that one human lung tumor cell line (Calu-3) has been identified which expresses gp160 but not the EGFR on its surface. These results indicate that there are characteristics which distinguish gp160 from the EFGR, and we establish here that these distinguishing features reflect differences at the protein moiety and not simply differential glycosylation. We conclude from these studies that we have identified and characterized a cell surface molecule that resembles in several respects the epidermal growth factor receptor. This cell surface molecule represents a potentially useful target for the immunotherapy and diagnosis of human non-small cell lung cancer.
Cancer Research 08/1989; 49(13):3642-9. · 7.86 Impact Factor
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Current topics in microbiology and immunology 02/1989; 152:201-10. · 4.93 Impact Factor
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ABSTRACT: Monoclonal antibody 5E8 which is specific for a Mr 160,000 glycoprotein (gp160) on the surface of human lung cancer was radiolabeled with 125I. Radiolabeled 5E8 antibody is shown here to suppress the growth of gp160 positive human lung tumor cell lines in a dose-dependent fashion, but this same radiolabeled antibody does not alter the growth of gp160 negative lung tumor cell lines. Neither the unlabeled 5E8 nor a control radiolabeled monoclonal antibody has any effect upon the growth of gp160 positive tumors. The specificity of radiolabeled antibody mediated tumor killing is further demonstrated by the ability of unlabeled 5E8 to inhibit tumor killing by 125I-5E8. The efficiency with which the labeled tumor specific antibody suppressed tumor colony formation is enhanced by increasing the molar ratio of 125I to 5E8. This ratio could be increased to a level of two without affecting the capacity of the antibody to bind to the cell surface antigen. An attempt to increase the efficiency of tumor killing by the addition of a second antibody subsequent to incubation with 125I-5E8 was unsuccessful. These results indicate that 125I is a viable isotope and gp160 represents an appropriate target for radioimmunotherapy of human lung cancer.
Cancer Research 06/1988; 48(10):2768-73. · 7.86 Impact Factor
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ABSTRACT: A monoclonal antibody (5E8) has been used to identify and structurally characterize a previously unreported macromolecule present on the surface of human lung tumors. This antibody was derived from a hybrid clone that was produced using spleen cells of mice immunized with a surgically excised squamous cell carcinoma. Using immunofluorescence, the 5E8 antibody was observed to stain many different human lung tumor cell lines and surgically excised human lung tumors including squamous cell carcinomas, adenocarcinomas, alveolar carcinomas, and a portion of the large cell tumors tested. With few exceptions, notably the basal layer of the skin, little or no detectable staining of 5E8 to normal human tissues (lung, brain, kidney, heart, stomach, breast, erythrocytes, or lymphocytes) was observed. The 5E8 antibody was used to immunoprecipitate detergent lysates of biosynthetically labeled or surface radioiodinated lung tumors. Analysis of the immunoprecipitates by sodium dodecyl sulfate gel electrophoresis revealed a major band and a faster migrating second minor band. The molecular weights of these two proteins were estimated to be 160,000 and 120,000, respectively. The addition of a reducing agent to the gels did not alter the migration pattern of the immunoprecipitated macromolecules. The removal of a terminal carbohydrate, sialic acid, did not restrict the binding of 5E8 to the tumor-associated antigen. However, labeling studies using galactose oxidase and tritiated borohydride revealed the presence of galactose on the immunoprecipitated protein. This major Mr 160,000 glycoprotein that was identified on two different human lung tumor cell lines was also found on a human large cell tumor tissue obtained by surgical biopsy. The 5E8 antibody and the Mr 160,000 glycoprotein that it recognizes represent two very useful components with which to test several new antibody-mediated drug delivery systems in the treatment of human lung tumors. The tumor-associated glycoprotein also represents a potential analyte for a diagnostic or prognostic immunoassay for lung cancer.
Cancer Research 01/1987; 46(12 Pt 1):6446-51. · 7.86 Impact Factor
