The synthetic peptides were conjugated with hemocyanin from Keyhole Limpet (KLH) according to the published procedures [14]. complement-dependent cytotoxicity and apoptosis of cultured malignancy cells indicating the surface nature of Ig-like proteins. Based on these experimental observations, it was hypothesized that this expressions of these immunoglobulin superfamily (IgSF) proteins may be relevant to the immune protection and proliferations of malignancy cells during carcinogenesis or malignancy progression. Surface-bound TCR-like proteins as well as immunoglobulins may be the potential targets for RP215-based anti-cancer drugs. == Electronic supplementary material == The online version of this article (doi:10.1007/s00262-011-1088-1) contains supplementary material, which is available to authorized users. Keywords:RP215, CA215, T-cell receptor, Malignancy cells, Immunoglobulin superfamily proteins, Carbohydrate-associated epitope == Introduction == In previous publications, we have reported biochemical and immunological studies of a monoclonal antibody (Mab) designated as RP215, which was generated against the cell extract of an ovarian malignancy cell collection, OC-3-VGH [1,2]. A SAR405 preliminary analysis with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) was performed for the affinity-purified malignancy antigens named CA215. It was found that the majority of tryptic peptide fragments were homologous to the 5070 kDa heavy chains of SAR405 antibody-like immunoglobulin (Ig) molecules expressed by malignancy cells [1]. Subsequently, it was documented that RP215 recognizes a carbohydrate-associated epitope(s) in CA215 [1,3]. However, RP215 does not cross-react with the Igs from normal human B cell origins [1]. RP215 was also demonstrated to inhibit the growth of many different malignancy cells through in vitro apoptosis assay as well as in vivo nude mouse experiments [4,5]. Furthermore, RP215 was employed in immunoassays to detect and monitor serum CA215 levels from patients confirmed with cancers of many different tissue origins [6]. The results of these studies suggest that RP215 in humanized form could be a suitable candidate for the development of multi-indication anti-cancer drugs [35]. Besides malignancy cellexpressed human IgG, CA215 also contains many other glycoproteins with carbohydrate-associated epitope recognized by RP215, as long as suitable glycosylation sites are available for these proteins. Therefore, additional MALDI-TOF MS data made up of more than 120 peptide fragments derived from CA215 were generated and further analyzed for their homology and molecular identity. Unexpectedly, Rabbit polyclonal to Filamin A.FLNA a ubiquitous cytoskeletal protein that promotes orthogonal branching of actin filaments and links actin filaments to membrane glycoproteins.Plays an essential role in embryonic cell migration.Anchors various transmembrane proteins to the actin cyto as many as 60% of the tryptic peptide fragments revealed high degrees of homology to those of immunoglobulin superfamily (IgSF) proteins. Among the peptide fragments, those of T-cell receptors (TCRs) and cell adhesion molecules were frequently identified from your malignancy cellderived CA215, in addition to the antibody-like ones reported previously [1]. TCRs are known to be universally expressed among T-cell subsets of hematopoietic origins [79]. Expressions of TCR-like proteins either in normal or in malignancy cells have rarely been reported or analyzed in detail [10]. Therefore, in this communication, we would like to statement our immunological and molecular biological studies regarding the expressions of TCR-like proteins as well as common Ig-like cell adhesion molecules among malignancy cell lines and cancerous tissues. This statement should represent our initial effort toward the understanding of the malignancy cell expressions of TCR-like proteins and selected cell adhesion molecules as well as their potential functions during carcinogenesis or cell proliferation [1012]. SAR405 == Materials and methods == == Chemicals == All the chemicals and reagents were obtained from Sigma unless normally specified. == Malignancy cell lines == The ovarian malignancy cell line of serous origin, OC-3-VGH, was established by the Department of Obstetrics and Gynecology at Veterans General Hospital, Taipei, Taiwan, in 1986 [13]. The malignancy cells were cultured in RPMI medium made up of 10% fetal calf serum. SAR405 The shed culture media SAR405 were collected for biochemical, immunological and molecular biological analysis as well as for CA215.