title: Role of IL13RA2 in Sunitinib Resistance in Clear Cell Renal Cell Carcinoma.
abstract: Vascular endothelial growth factor (VEGF) and mammalian target of rapamycin are well-known therapeutic targets for renal cell carcinoma (RCC). Sunitinib is an agent that targets VEGF receptors and is considered to be a standard treatment for metastatic or unresectable clear cell RCC (ccRCC). However, ccRCC eventually develops resistance to sunitinib in most cases, and the mechanisms underlying this resistance are not fully elucidated. In the present study, we established unique primary xenograft models, KURC1 (Kyoto University Renal Cancer 1) and KURC2, from freshly isolated ccRCC specimens. The KURC1 xenograft initially responded to sunitinib treatment, however finally acquired resistance. KURC2 retained sensitivity to sunitinib for over 6 months. Comparing gene expression profiles between the two xenograft models with different sensitivity to sunitinib, we identified interleukin 13 receptor alpha 2 (IL13RA2) as a candidate molecule associated with the acquired sunitinib-resistance in ccRCC. And patients with high IL13RA2 expression in immunohistochemistry in primary ccRCC tumor tends to have sunitinib-resistant metastatic site. Next, we showed that sunitinib-sensitive 786-O cells acquired resistance in vivo when IL13RA2 was overexpressed. Conversely, shRNA-mediated knockdown of IL13RA2 successfully overcame the sunitinib-resistance in Caki-1 cells. Histopathological analyses revealed that IL13RA2 repressed sunitinib-induced apoptosis without increasing tumor vasculature in vivo. To our knowledge, this is a novel mechanism of developing resistance to sunitinib in a certain population of ccRCC, and these results indicate that IL13RA2 could be one of potential target to overcome sunitinib resistance.
authors.affiliation: Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Noboru
authors.initials: N
authors.lastname: Shibasaki
authors.affiliation: Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Toshinari
authors.initials: T
authors.lastname: Yamasaki
authors.affiliation: Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Kanno
authors.affiliation: Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Ryuichiro
authors.initials: R
authors.lastname: Arakaki
authors.affiliation: Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Sakamoto
authors.affiliation: Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Utsunomiya
authors.affiliation: Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Inoue
authors.affiliation: Department of Diagnostic Pathology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Tatsuaki
authors.initials: T
authors.lastname: Tsuruyama
authors.affiliation: Laboratory for Malignancy Control Research, Medical Innovation Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Eijiro
authors.initials: E
authors.lastname: Nakamura
authors.affiliation: Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Ogawa
authors.affiliation: Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Kamba
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D002292:Carcinoma, Renal Cell / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D019008:Drug Resistance, Neoplasm / Q000235:genetics; D005260:Female; D006801:Humans; D007211:Indoles / Q000627:therapeutic use*; D053663:Interleukin-13 Receptor alpha2 Subunit / Q000235:genetics / Q000378:metabolism*; D007680:Kidney Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism*; D008807:Mice, Inbred BALB C; D016513:Mice, SCID; D011758:Pyrroles / Q000627:therapeutic use*; D000077210:Sunitinib; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D007211:Indoles; D053663:Interleukin-13 Receptor alpha2 Subunit; D011758:Pyrroles; D000077210:Sunitinib