Identification of a cell surface protein, p97, in human melanomas and certain other neoplasms.

Abstract

BALB/c mice were immunized with a human melanoma cell line, SK-MEL 28, and their spleen cells were fused with mouse NS-1 myeloma cells. Hybrid cells were tested in an indirect 25SI-labeled protein A assay for production of antibodies that bound to surface antigens of SK-MEL 28 melanoma cells but not to autologous skin fibroblasts. One hybridoma, designated 4.1, had the required specificity. It Many human neoplasms express tumor-associated antigens (1). With few exceptions, however, methodological difficulties have hampered attempts to purify and to characterize these antigens. Monoclonal antibodies produced by hybridomas (2) offer great promise as a means of identifying tumor-associated antigens (3). The antibodies can also be used to purify the antigens by immunoprecipitation for subsequent biochemical characterization.Antigens associated with human melanomas have been studied extensively. Melanoma patients have been found to mount both cell-mediated and humoral immune reactions to their tumors (4, 5), and serological studies with melanoma patients' sera indicated the presence of two classes of melanoma-associated antigens (6). Antigens of one class are each restricted to a single melanoma. Those of the other class are shared by many melanomas and a small fraction of other tumors.Yeh and coworkers (7) The various target cell lines were grown in 5% CO2 in air in Waymouth's culture medium buffered with NaHCO3 and supplemented with 30% fetal calf serum, 1% nonessential amino acids, 1 mM sodium pyruvate, and 2 mM L-glutamine (7).

The melanoma proteoglycan: restricted expression on microspikes, a specific microdomain of the cell surface.

“…The [35S]methionine/[3H]glucosamine-labeled DEAE-binding fraction was immunoprecipitated as previously described (64). Briefly, the antigen fraction was preadsorbed with rabbit anti-mouse IgG (2% vol/vol) and fixed and heat-killed S. aureus (2 % wt/vol).…”

Heterogeneity of the human transferrin receptor and use of anti‐transferrin receptor antibodies to detect tumours in vivo

“…Many tumours have been found to express up to IxlO'* times the amount of TFR when compared to their normal counterparts (15)(16)(17)(18). The nature of the TFR's involvement with malignant transformation still remains to be determined, but it is interesting tbat rearrangements in the region of the human chromosome 3 coding for the TFR and other proteins involved in iron transport (i.e., transferrin and P97) (19) have, in some instances, been reported to be associated with malignant transformations (20).…”

Strong antitumor activities of IgG3 antibodies to a human melanoma-associated ganglioside.

“…One of the most straightforward of these is to use the antibodies alone, without further modification. However, this approach requires antibodies that have strong antitumor effects either by themselves or in the presence of complement or effector cells such as killer (K) cells or macrophages (1).We have produced mouse monoclonal antibodies to several cell surface antigens that are primarily expressed in human melanomas (1)(2)(3)(4). One of the most specific of these antigens is a GD3 ganglioside, which was first defined by Dippold and co-workers (5, 6), using their antibody R24, and subsequently by Yeh and co-workers (7,8), using an IgM antibody, 4.2.…”