Abstract: Provided is the present invention focusing on roles of IL-26 present in humans but not in mice by characterizing molecular mechanisms involved in interspecies differences in terms of efficacy of EGFR-TKI. The present inventors found that human cancers are exposed to IL-26 in a tumor microenvironment (TME), activating the EGFR-TKI bypass pathway, while suppression of IL-26 overcomes EGFR-TKI resistance in cancers. Furthermore, the present inventors identified EphA3 as a new functional receptor for IL-26 of TNBC. Therefore, the present invention provides a pharmaceutical composition for use in combination with an anticancer drug for treating cancer in a patient, the pharmaceutical composition containing a drug that reverses resistance to the anticancer drug by IL-26 as an active ingredient. Furthermore, the present invention provides a humanized anti-IL-26 antibody, and a therapeutic or preventive agent for refractory immune disorders or cancer using the antibody.

Abstract: It is intended to provide an anti-human CD26 antibody which permits analysis, etc., of the expression of CD26 in cancer tissues, immune tissues, or the like, for example, in order to select a patient applicable to treatment or to monitor therapeutic effects, and can also be used in immunostaining. The present invention relates to an anti-human CD26 monoclonal antibody or an antigen-binding fragment thereof, binding to an epitope which is recognized by a monoclonal antibody produced by a hybridoma deposited under Accession No. NITE BP-01642, a hybridoma deposited under Accession No. NITE BP-01643, or a hybridoma deposited under Accession No. NITE BP-01644.

Abstract: It is intended to provide an anti-human CD26 antibody which permits analysis, etc., of the expression of CD26 in cancer tissues, immune tissues, or the like, for example, in order to select a patient applicable to treatment or to monitor therapeutic effects, and can also be used in immunostaining. The present invention relates to an anti-human CD26 monoclonal antibody or an antigen-binding fragment thereof, binding to an epitope which is recognized by a monoclonal antibody produced by a hybridoma deposited under Accession No. NITE BP-01642, a hybridoma deposited under Accession No. NITE BP-01643, or a hybridoma deposited under Accession No. NITE BP-01644.

Abstract: The present invention relates to a therapeutic agent for malignant mesothelioma comprising a substance which inhibits binding of CD26 to extracellular matrix such as an siRNA targeting CD26 cDNA or an anti-CD26 antibody. The present invention also relates to a method of treating malignant mesothelioma, which comprises administering the substance to a patient in need thereof.

Abstract: The present invention relates to a therapeutic agent for malignant mesothelioma comprising a substance which inhibits binding of CD26 to extracellular matrix such as an siRNA targeting CD26 cDNA or an anti-CD26 antibody. The present invention also relates to a method of treating malignant mesothelioma, which comprises administering the substance to a patient in need thereof.

Abstract: The present invention relates to a therapeutic agent for malignant mesothelioma comprising a substance which inhibits binding of CD26 to extracellular matrix such as an siRNA targeting CD26 cDNA or an anti-CD26 antibody. The present invention also relates to a method of treating malignant mesothelioma, which comprises administering the substance to a patient in need thereof.

Abstract: The present invention provides methods of identifying a substance that down-regulates or up-regulates an immune response and kits used for the identification methods. A method of this invention comprises detecting a substance that inhibits or enhances the interaction between CD26 and caveolin-1. Another method comprises detecting a substance that inhibits or enhances the interaction between caveolin-1 and Tollip. Still another method comprises detecting a substance that inhibits or enhances the interaction among caveolin-1, Tollip, and IRAK-1. The present invention also relates to immunoregulatory agents comprising a substance that down-regulates an immune response, such as siRNA against caveolin-1 or Tollip. The invention further provides immunoregulatory agents comprising a substance that up-regulates an immune response. These agents are useful for treating inflammatory diseases, autoimmune diseases, or other immune-mediated disorders.

Abstract: The present invention provides methods of identifying a substance that down-regulates or up-regulates an immune response and kits used for the identification methods. A method of this invention comprises detecting a substance that inhibits or enhances the interaction between CD26 and caveolin-1. Another method comprises detecting a substance that inhibits or enhances the interaction between caveolin-1 and Tollip. Still another method comprises detecting a substance that inhibits or enhances the interaction among caveolin-1, Tollip, and IRAK-1. The present invention also relates to immunoregulatory agents comprising a substance that down-regulates an immune response, such as siRNA against caveolin-1 or Tollip. The invention further provides immunoregulatory agents comprising a substance that up-regulates an immune response. These agents are useful for treating inflammatory diseases, autoimmune diseases, or other immune-mediated disorders.