Immunotoxins directed against the high‐molecular‐weight melanoma‐associated antigen. Identification of potent antibody‐toxin combinations

Godal, Aslak; Kumle, Brita; Pihl, Alexander; Juell, Siri; Fodstad, Øystein

doi:10.1002/ijc.2910520423

Cited by 21 publications

(14 citation statements)

References 28 publications

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“…The BM7 antibody, which recognises a glycosylated epitope on the MUC1 mucin, was kindly provided by Dr S Kaul (Frauenklinik, Heidelberg, Germany). The antibody was conjugated to PE (obtained from Dr Darrel Galloway (University of Ohio, Columbus, OH, USA) by a thioether bond formed with the reagent sulfo-SMCC (sulfo-succinimidyl-4-(Nmaleimidomethyl) cyclohexane-1-carboxylate) (Pierce, Rockford, IL, USA) as described earlier (Godal et al, 1992).…”

Section: Methodsmentioning

confidence: 99%

Synergistic anti-cancer effects of immunotoxin and cyclosporin in vitro and in vivo

2009

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BACKGROUND: The clinical use of immunotoxins (ITs) has been hampered by hepatotoxicity, and the induction of a strong human-anti-IT response. The human-anti-IT response results in neutralisation of the immunoconjugates, rendering repetitive treatment inefficacious. METHODS: We evaluated the combination of cyclosporin A (CsA) with various Pseudomonas exotoxin A-based ITs in human breast, cervical, and prostate cancer cell lines measured by protein synthesis, cell viability, and TUNEL assay. Furthermore, expression of essential proteins were analysed by western blot. We used cervical cancer model in nude rats to evaluate the anti-metastatic effect of the combination. The anti-immunogenic response by the CsA treatment was investigated in immunocompetent rats. RESULTS: The combination of CsA with ITs caused remarkable synergistic cytotoxicity, in several cancer cell lines, characterised by protein synthesis inhibition, decreased cell viability, and an increased apoptotic index. Furthermore, the combination strongly inhibited formation of metastases in a cervical cancer model in nude rats with a statistically significant increase in median survival time of the combination-treated animals, as compared with those receiving a suboptimal dose of IT alone. Notably, we found in immunocompetent rats that the anti-IT immunoresponse elicited by repeated administration of IT was efficiently abrogated by CsA; notably the antibody responds towards the highly immunogenic PE was shown to be prevented. CONCLUSION: The combination of ITs and CsA might constitute a significant improvement in the clinical potential of systemic IT treatment of cancer patients.

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Section: Methodsmentioning

confidence: 99%

Synergistic anti-cancer effects of immunotoxin and cyclosporin in vitro and in vivo

2009

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“…13 The antibody was conjugated to PE (obtained from Dr. D. Galloway, University of Ohio, Columbus, OH) by a thioether bond formed with the reagent sulfo-SMCC (Pierce, Rockford, IL) as described previously. 14 The broad-spectrum caspase inhibitor z-VAD-FMK, the cathepsin B/L inhibitor z-FA.FMK, the caspase inhibitor set II and the proteasome inhibitor lactacystin (Calbiochem, San Diego, CA) were resuspended in DMSO (Sigma, St. Louis, MO).…”

Section: Methodsmentioning

confidence: 99%

Downregulation of the antiapoptotic MCL‐1 protein and apoptosis in MA‐11 breast cancer cells induced by an anti‐epidermal growth factor receptor–Pseudomonas exotoxin a immunotoxin

Andersson

Juell

Fodstad

2004

Intl Journal of Cancer

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Pseudomonas exotoxin (PE)-containing immunotoxins (ITs) act by arresting protein synthesis and promoting apoptosis, but the mechanisms of the induced apoptosis and the relationship to protein synthesis inhibition is not well elucidated. We studied these effects in MA Key words: immunotoxin; apoptosis; Mcl-1; breast cancerITs represent one group of targeted therapeutics that have shown promising efficacy in patients for whom standard treatment is no longer an option. 1,2 ITs are dimeric proteins consisting of a targeting moiety linked to a toxin (ricin, PE, DT), which induce arrest of protein synthesis and result in cell death. 1 The targeting moiety binds to molecules expressed on cancer cells, theoretically leaving normal cells unaffected.The mechanism of action of such toxins and ITs is not, as previously believed, merely inhibition of protein synthesis in the cell. Thus, ricin, PE and DT may also induce apoptosis, a feature of major importance in cancer therapy. 3,4 Two common features of apoptotic cell death are activation of a group of cysteine proteases called caspases and caspase-catalyzed cleavage of so-called death substrates, such as the nuclear repair enzyme PARP. 5 Caspases are present in cells as inactive precursors, which are proteolytically activated upon induction of apoptosis. The protein substrates of caspases include proteins of regulatory or structural function in cell life. Caspases play a central role in the apoptotic program, functioning as initiators and executors of the apoptotic pathway. Caspase-3, e.g., is directly involved in apoptosis induced by both toxins and ITs in several human tumor cell lines. 6 -8 The Bcl-2 protein family is a major molecular modulator of apoptosis. 9,10 These proteins can be divided into 2 groups, including antiapoptotic (Bcl-2, Mcl-1, Bcl-X L ) and proapoptotic (Bax, Bak, Bad) molecules that regulate cellular sensitivity to drugs at the mitochondrial level. Pro-and antiapoptotic family members can heterodimerize and titrate each other's function, implying that their relative concentration may act as a balance in the suicide program. 11 Therapeutic drugs can modulate the expression of Bcl-2 family members, their activity and their subcellular localization.We have previously shown that the 425.3PE IT increased symptom-free survival in a human breast cancer model in nude rats 12 and wanted to investigate the mechanisms underlying the ITinduced cell death. This IT consists of the 425.3 MAb, which targets the EGFr and covalently links to the bacterial toxin PE. 12 It is well known that PE-containing ITs induce protein synthesis arrest by inactivation of EF-2, but it remains to be elucidated how this is linked to apoptosis.In the present study, we demonstrate simultaneous induction of apoptosis and protein synthesis inhibition by the holo-PE-containing IT in MA-11 breast cancer cells. Thus, upon IT treatment, expression of the antiapoptotic protein Mcl-1 was quickly and markedly reduced. The IT also induced loss of ⌬⌿ mito and activation of the caspase cascade, f...

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“…Several in vitro as well as animal studies have demonstrated that targeting MCSP with antibodies alone or conjugated to toxins effectively inhibits tumor growth. [22][23][24] On the basis of these findings, MCSP-specific mAbs alone or in conjugation with toxins have been used to treat patients with advanced melanoma. [25][26][27] Finally, immunizing Stage IV melanoma patients with an anti-idiotypic mAb mimicking the determinant recognized by the anti-MCSP mAb 763.74 resulted in prolonged survival.…”

Section: T Cell Reactivity Of Healthy Donors and Tumor Patientsmentioning

confidence: 99%

Melanoma‐associated chondroitin sulphate proteoglycan as a new target antigen for CD4⁺ T cells in melanoma patients

Erfurt

Müller

Emmerling

et al. 2009

Intl Journal of Cancer

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Melanoma-associated chondroitin sulfate proteoglycan (MCSP) (also known as high molecular weight-melanoma-associated antigen) represents an interesting target antigen for cancer immunotherapy which is expressed on human melanomas and other tumors such as breast carcinomas, gliomas, neuroblastomas and acute leukemias. MCSP seems to play an important functional role in melanoma as it is involved in tumor cell migration, invasion and angiogenesis. In this study, we isolated CD4 1 T helper cells from the blood of a healthy donor, recognizing a peptide from the MCSP core protein presented by HLA-DBR1*1101 molecules. T cell reactivity against the identified peptide could be detected in the blood of healthy donors and melanoma patients. MCSP specific T cells from the blood of a patient could be readily expanded by repeated peptide stimulation and recognized MCSP and HLA-DR expressing tumor cells. Our findings suggest that vaccination against MCSP helper T cell epitopes might be a promising approach to fight melanoma. ' 2008 Wiley-Liss, Inc. Key words: MCSP; melanoma; peptide; T helper cells; tumor antigenFollowing the identification of tumor-associated antigens recognized by T cells on human tumor cells, numerous clinical vaccination studies have been performed in patients with metastatic melanoma. Accompanied by an improvement of vaccine approaches including new adjuvants such as CpG oligonucleotides and further development in the field of immuno-monitoring, the induction of antigen-specific T cell responses in the blood of tumor patients has been demonstrated in a number of studies. However, significant tumor regressions, especially complete responses in patients with visceral metastases have been observed infrequently, and in most studies overall response rates did not exceed 10%. 1 One obstacle might be immune escape by downregulation or complete loss of antigen expression as many antigens identified so far do not play an essential functional role for the tumor. [2][3][4] To overcome this it would be particularly important to choose a suitable target antigen for vaccination therapy, which should be broadly expressed and functionally relevant for the tumor. On our search for suitable target antigens for the active-specific immunotherapy of melanoma, we focused on the human melanoma-associated chondroitin sulfate proteoglycan (MCSP), also known as high molecular weight-melanoma-associated antigen, which has been shown to be expressed in the majority of human melanoma lesions and cultured cells with a limited expression in normal tissues. 5,6 In addition, MCSP expression was found in uveal melanoma, which is refractory to standard chemotherapy. 7 MCSP represents an unique glycoprotein-proteoglycan complex, with a 250 kDa core glycoprotein to which, via serine residues, the larger than 450 kDa proteoglycan component is attached. 8 MCSP has been implicated for some time in numerous aspects of melanoma cell biology, including adhesion, spreading and migration. In fact, melanoma cell adhesion, chemotactic responses to fi...

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Immunotoxins directed against the high‐molecular‐weight melanoma‐associated antigen. Identification of potent antibody‐toxin combinations

Cited by 21 publications

References 28 publications

Synergistic anti-cancer effects of immunotoxin and cyclosporin in vitro and in vivo

Synergistic anti-cancer effects of immunotoxin and cyclosporin in vitro and in vivo

Downregulation of the antiapoptotic MCL‐1 protein and apoptosis in MA‐11 breast cancer cells induced by an anti‐epidermal growth factor receptor–Pseudomonas exotoxin a immunotoxin

Melanoma‐associated chondroitin sulphate proteoglycan as a new target antigen for CD4⁺ T cells in melanoma patients

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Immunotoxins directed against the high‐molecular‐weight melanoma‐associated antigen. Identification of potent antibody‐toxin combinations

Cited by 21 publications

References 28 publications

Synergistic anti-cancer effects of immunotoxin and cyclosporin in vitro and in vivo

Synergistic anti-cancer effects of immunotoxin and cyclosporin in vitro and in vivo

Downregulation of the antiapoptotic MCL‐1 protein and apoptosis in MA‐11 breast cancer cells induced by an anti‐epidermal growth factor receptor–Pseudomonas exotoxin a immunotoxin

Melanoma‐associated chondroitin sulphate proteoglycan as a new target antigen for CD4+ T cells in melanoma patients

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Melanoma‐associated chondroitin sulphate proteoglycan as a new target antigen for CD4⁺ T cells in melanoma patients