{"id":697,"date":"2024-12-21T02:03:33","date_gmt":"2024-12-21T02:03:33","guid":{"rendered":"http:\/\/changingfaceofamerica.com\/?p=697"},"modified":"2024-12-21T02:03:33","modified_gmt":"2024-12-21T02:03:33","slug":"moreover-therapeutic-experiences-clearly-indicated-that-hex3-unlike-conventional-anti-egfr-antibodies-was-effective-against-colorectal-cancer-crc-cells-with-mutant-kras-braf-or-pik3ca","status":"publish","type":"post","link":"https:\/\/changingfaceofamerica.com\/?p=697","title":{"rendered":"\ufeffMoreover, therapeutic experiences clearly indicated that hEx3, unlike conventional anti-EGFR antibodies, was effective against colorectal cancer (CRC) cells with mutant KRAS, BRAF, or PIK3CA"},"content":{"rendered":"

\ufeffMoreover, therapeutic experiences clearly indicated that hEx3, unlike conventional anti-EGFR antibodies, was effective against colorectal cancer (CRC) cells with mutant KRAS, BRAF, or PIK3CA. or without immunological synapse formation. Using an anti-EGFR\/CD3 TDB, hEx3, we visualized and quantified T cellCtumor cell contact and demonstrated a correlation between the degree of cell contact and TDB efficacy. We also found that cytokines, including interferon-gamma (IFN)?and tumor necrosis factor-alpha (TNF)?secreted by activated T cells, damaged tumor cells Rtp3<\/a> in a cell contact-independent manner. Moreover, therapeutic experiences clearly indicated that hEx3, unlike conventional anti-EGFR antibodies, was effective against colorectal cancer (CRC) cells with mutant KRAS, BRAF, or PIK3CA. In a pharmacokinetic analysis, T cells spread gradually in accordance with the hEx3 distribution within tumor tissue. Accordingly, we propose that TDBs should have four action steps: 1st, passive targeting via size-dependent tumor accumulation; 2nd, active targeting via specific binding to tumor cells; 3rd, T cell redirection toward tumor cells; and 4th, TDB-induced cell contact-dependent (direct) or -independent (indirect) tumor cell killing. Finally, our TDB hEx3 may be a promising reagent against refractory CRC with an oncogenic mutation associated with a poor prognosis. Electronic supplementary material The online version of this article (10.1007\/s00262-020-02667-9) contains supplementary Biapenem material, which is available to authorized users. Keywords: Antibody therapeutics, Bispecific antibody (BsAb), T cell-dependent bispecific antibody (TDB), Immunological synapse, Immunotherapy, Colorectal cancer Introduction Colorectal cancer (CRC) is the third most common malignancy worldwide. Despite the fact that mortality rates have been decreasing over recent years Biapenem<\/a> because of developments in related knowledge and technologies, the 5-year relative survival rate is still less than 70%, even in advanced countries [1, 2]. Anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (mAbs), such as cetuximab and panitumumab, have been widely used in the treatment of metastatic or advanced CRC [3, 4]. Although these antibodies can kill CRC cells via a neutralizing effect on EGFR signaling, primary or acquired oncogenic mutations in downstream molecules of the EGFR signaling pathway, e.g., KRAS, BRAF, or PIK3CA, can cause therapeutic resistance to anti-EGFR mAbs [5C8]. On the other hand, bispecific antibodies (BsAbs) as next-generation antibody therapies are anticipated to be effective against therapy-resistant or recurrent CRC due to their unique bioactivities not found in conventional therapeutic antibodies. Among BsAbs, we focused on T cell-dependent BsAbs (TDBs), in which an antitumor antigen antibody and an anti-CD3 antibody are combined in one antibody structure. TDBs form a bridge between tumor cells and T cells, which can induce T cell activation. Subsequently, activated T cells can kill tumor cells effectively without T cell receptor (TCR)-mediated recognition of tumor antigen presented by major histocompatibility complex (MHC) molecules (Fig.?1a). Unfortunately, MHC molecules in tumor cells disappear, and disturbed tumor antigen processing and presentation should cause therapeutic resistance or recurrence [9]. On the other hand, TDBs with MHC-peptide-independent activation through TCRs cannot be influenced by these resistance mechanisms [10]. Open in a separate window Fig. 1 Characteristics of hEx3 (an anti-EGFR\/CD3 BsAb). a Principle of TDB action. TDB forms a bridge between tumor cells and T cells, inducing T cell Biapenem activation and subsequent tumor cell killing without recognizing tumor antigen presentation by MHC molecules. b Schematic illustration of the hEx3 structure. c Binding affinity of hEx3 for CRC cells and T cells, as analyzed by flow cytometry. d In vitro study of T cell redirection and tumor cell elimination by hEx3 Immunological synapse (IS) formation, as a cutting-edge mechanism for T cell-mediated killing of tumor cells via TCR signaling, is also considered an important mechanism of action (MOA) of TDBs. However, T cells can kill tumor cells without IS formation [11, 12]. In this study, we focused on T cellCtumor cell contact as an important initial step in T cellCmediated tumor cell killing, with or without IS formation. We visualized TDB-induced cell contact to investigate the MOA of our TDB, the anti-EGFR\/CD3 BsAb hEx3 [13C15]. We found that hEx3-induced T cell activation was able to cause both cell contact-dependent tumor cell killing (direct.<\/p>\n","protected":false},"excerpt":{"rendered":"

\ufeffMoreover, therapeutic experiences clearly indicated that hEx3, unlike conventional anti-EGFR antibodies, was effective against colorectal cancer (CRC) cells with mutant KRAS, BRAF, or PIK3CA. or without immunological synapse formation. Using an anti-EGFR\/CD3 TDB, hEx3, we visualized and quantified T cellCtumor cell contact and demonstrated a correlation between the degree of cell contact and TDB efficacy. […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[27],"tags":[],"class_list":["post-697","post","type-post","status-publish","format-standard","hentry","category-alpha2-adrenergic-receptors"],"_links":{"self":[{"href":"https:\/\/changingfaceofamerica.com\/index.php?rest_route=\/wp\/v2\/posts\/697","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/changingfaceofamerica.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/changingfaceofamerica.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/changingfaceofamerica.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/changingfaceofamerica.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=697"}],"version-history":[{"count":1,"href":"https:\/\/changingfaceofamerica.com\/index.php?rest_route=\/wp\/v2\/posts\/697\/revisions"}],"predecessor-version":[{"id":698,"href":"https:\/\/changingfaceofamerica.com\/index.php?rest_route=\/wp\/v2\/posts\/697\/revisions\/698"}],"wp:attachment":[{"href":"https:\/\/changingfaceofamerica.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=697"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/changingfaceofamerica.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=697"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/changingfaceofamerica.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=697"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}