TY - JOUR
T1 - Hypoxia-Induced PLOD2 is a Key Regulator in Epithelial-Mesenchymal Transition and Chemoresistance in Biliary Tract Cancer
AU - Okumura, Yuichiro
AU - Noda, Takehiro
AU - Eguchi, Hidetoshi
AU - Sakamoto, Takuya
AU - Iwagami, Yoshifumi
AU - Yamada, Daisaku
AU - Asaoka, Tadafumi
AU - Wada, Hiroshi
AU - Kawamoto, Koichi
AU - Gotoh, Kunihito
AU - Kobayashi, Shogo
AU - Takeda, Yutaka
AU - Tanemura, Masahiro
AU - Umeshita, Koji
AU - Doki, Yuichiro
AU - Mori, Masaki
PY - 2018/11/1
Y1 - 2018/11/1
N2 - Background: The prognosis of biliary tract cancer (BTC) is unfavorable due to its chemoresistance. Hypoxia triggers epithelial-to-mesenchymal transition (EMT), which is closely related to drug resistance. In this study, we focused on the functional roles of procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2), a hypoxia-induced gene, in BTC, and assessed the clinical significance of PLOD2. Methods: The expression of PLOD2 under hypoxia was assessed in BTC cell lines. Gemcitabine-resistant (GR) BTC cell lines were transfected with small interfering RNA (siRNA) against PLOD2, and EMT markers and chemoresistance were evaluated. PLOD2 expression was also characterized using immunohistochemistry in BTC clinical specimens following resection. Patient survival was analyzed and the role of PLOD2 expression was examined. Results: The expression of PLOD2 was induced by hypoxia in vitro and was upregulated in BTC-GR cell lines, which had low expression of epithelial markers and high expression of mesenchymal markers. Downregulation of PLOD2 by siRNA resulted in improved chemoresistance, recovery of epithelial markers, and reduction of mesenchymal markers. In the resected BTC samples, PLOD2 expression was significantly correlated with lymph node metastasis (p = 0.037) and stage (p = 0.001). Recurrence-free survival (p = 0.011) and overall survival (p < 0.001) rates were significantly lower in patients with high expression of PLOD2. PLOD2 expression was an independent prognostic factor for overall survival (p = 0.019). Conclusions: The expression of PLOD2 influenced chemoresistance through EMT, and high expression of PLOD2 was a significant unfavorable prognostic factor in BTC patients. PLOD2 might be a potential therapeutic target for overcoming chemoresistance.
AB - Background: The prognosis of biliary tract cancer (BTC) is unfavorable due to its chemoresistance. Hypoxia triggers epithelial-to-mesenchymal transition (EMT), which is closely related to drug resistance. In this study, we focused on the functional roles of procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2), a hypoxia-induced gene, in BTC, and assessed the clinical significance of PLOD2. Methods: The expression of PLOD2 under hypoxia was assessed in BTC cell lines. Gemcitabine-resistant (GR) BTC cell lines were transfected with small interfering RNA (siRNA) against PLOD2, and EMT markers and chemoresistance were evaluated. PLOD2 expression was also characterized using immunohistochemistry in BTC clinical specimens following resection. Patient survival was analyzed and the role of PLOD2 expression was examined. Results: The expression of PLOD2 was induced by hypoxia in vitro and was upregulated in BTC-GR cell lines, which had low expression of epithelial markers and high expression of mesenchymal markers. Downregulation of PLOD2 by siRNA resulted in improved chemoresistance, recovery of epithelial markers, and reduction of mesenchymal markers. In the resected BTC samples, PLOD2 expression was significantly correlated with lymph node metastasis (p = 0.037) and stage (p = 0.001). Recurrence-free survival (p = 0.011) and overall survival (p < 0.001) rates were significantly lower in patients with high expression of PLOD2. PLOD2 expression was an independent prognostic factor for overall survival (p = 0.019). Conclusions: The expression of PLOD2 influenced chemoresistance through EMT, and high expression of PLOD2 was a significant unfavorable prognostic factor in BTC patients. PLOD2 might be a potential therapeutic target for overcoming chemoresistance.
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U2 - 10.1245/s10434-018-6670-8
DO - 10.1245/s10434-018-6670-8
M3 - Article
C2 - 30105440
AN - SCOPUS:85051428110
VL - 25
SP - 3728
EP - 3737
JO - Annals of Surgical Oncology
JF - Annals of Surgical Oncology
SN - 1068-9265
IS - 12
ER -