CD44 Is Involved in Sunitinib Resistance and Poor Progression-free Survival After Sunitinib Treatment of Renal Cell Carcinoma
Yohei Sekino, Kenshiro Takemoto, Daiki Murata, Takashi Babasaki, Kohei Kobatake, Hiroyuki Kitano, Kenichiro Ikeda, Keisuke Goto, Shogo Inoue, Tetsutaro Hayashi, Daiki Taniyama, Masanobu Shigeta, Kazuya Kuraoka, Koji Mita, Mayumi Kaneko, Kazuhiro Sentani, Naohide Oue, Jun Teishima
Abstract
BACKGROUND/AIM: Sunitinib continues to be administered as a first-line therapeutic agent in metastatic renal cell carcinoma (mRCC). This study aimed to examine the role of CD44 in sunitinib resistance and as a predictive marker in mRCC. MATERIALS AND METHODS: We analyzed the effect of CD44 knockdown on sunitinib resistance in RCC cell lines using WST-1 assays. CD44 expression in mRCC patients treated with first-line sunitinib was determined by immunohistochemistry. We validated the findings of this study by in silico analysis. RESULTS: CD44 knockdown increased sensitivity to sunitinib. Immunohistochemical analysis revealed that 19 (34.5%) of 55 mRCC cases were positive for CD44. CD44-positive cases were associated with poor progression-free survival (PFS) after first-line sunitinib treatment. In the JAVELIN 101 study, high CD44 expression was significantly associated with poor PFS after sunitinib but not after avelumab + axitinib therapy. CONCLUSION: CD44 is involved in sunitinib resistance and may be a promising marker for sunitinib treatment in mRCC.