TY - JOUR
T1 - Dihydropyrimidine dehydrogenase overexpression correlates with potential resistance to 5-fluorouracil-based treatment in head and neck squamous cell carcinoma
AU - Shimada, Shoko
AU - Sano, Daisuke
AU - Hyakusoku, Hiroshi
AU - Hatano, Takashi
AU - Takahashi, Hideaki
AU - Isono, Yasuhiro
AU - Sawakuma, Kae
AU - Takada, Kentaro
AU - Okudela, Koji
AU - Oridate, Nobuhiko
N1 - Funding Information:
We thank Mari Mitsuka (Department of Biology and Function in Head and Neck, Yokohama City University Graduate School of Medicine, Yokohama, Japan) and Hideaki Mitsui (Department of Pathology) for their excellent technical assistance. This work was supported by Taiho Pharmaceutical Co., Ltd. (Tokyo, Japan).
Publisher Copyright:
©Translational Cancer Research.
PY - 2018/4/1
Y1 - 2018/4/1
N2 - Background: Although dihydropyrimidine dehydrogenase (DPD) expression has been reported to correlate with 5-fluorouracil (5-FU) resistance in several cancers, the relationship between DPD expression and chemotherapeutic resistance to 5-FU remains unclear in head and neck squamous cell carcinoma (HNSCC). The purpose of this study was to determine the impact of DPD expression on 5-FU sensitivity and survival in HNSCC patients receiving 5-FU-based treatment. Methods: To study the correlation between DPD expression and clinical outcome of HNSCC patients who had undergone concurrent chemoradiotherapy with 5-FU-based regimens, we first examined DPD mRNA expression of these patient samples. We next developed a 5-FU-resistant HNSCC cell line (HSC-3R) to clarify the association between DPD expression and 5-FU resistance. Clonogenic survival assay was performed to determine the sensitivity of HSC-3 cells and HSC-3R cells to 5-FU. DPD expression levels in parental HSC-3 and HSC-3R cell lines were then examined by Western blotting and real-time quantitative polymerase chain reaction analysis. Lastly, we performed WST-8 assay to examine the effects of 5-Chloro-2,4-dihydroxypyridine (CDHP), a 5-FU modulator to competitively inhibit DPD, on 5-FU cytotoxicity in the HSC-3 and HSC-3R cells, to evaluate if inhibition of DPD can restore the sensitivity of HNSCC cells to 5-FU. Results: Nineteen HNSCC patients who had undergone concurrent chemoradiotherapy with 5-FU-based regimens were enrolled in this study. The cut-off value for DPD mRNA expression calculated from the ROC curve was 8.53 against cancer-specific survival of these patients. The high-level DPD expression group showed significantly shorter overall and cancer-specific survival compared to the low-level DPD expression group (P=0.0018 and 0.0004, respectively). Both of protein and mRNA expression levels were greater in the HSC-3R cells than that in the HSC-3 cells. While HSC-3R cells showed 12.64-fold greater resistance to 5-FU compared with HSC-3 cells, the combination of 5-FU with CDHP had a significant inhibitory effect on 5-FU cytotoxicity in HSC-3R cells in CDHP exposure. Conclusions: In this study, we clarified that the high-level DPD expression group of HNSCC patients undergoing concurrent chemoradiotherapy with 5-FU-based regimens showed significantly shorter overall survival. The 5-FU-resistant cells established from HNSCC cells showed increased DPD expression and attenuated 5-FU resistance induced by CDHP. Our results suggested that a high level of DPD expression was correlated with 5-FU resistance and that DPD expression level might be a predictive biomarker in 5-FU-based chemoradiotherapy for HNSCC patients.
AB - Background: Although dihydropyrimidine dehydrogenase (DPD) expression has been reported to correlate with 5-fluorouracil (5-FU) resistance in several cancers, the relationship between DPD expression and chemotherapeutic resistance to 5-FU remains unclear in head and neck squamous cell carcinoma (HNSCC). The purpose of this study was to determine the impact of DPD expression on 5-FU sensitivity and survival in HNSCC patients receiving 5-FU-based treatment. Methods: To study the correlation between DPD expression and clinical outcome of HNSCC patients who had undergone concurrent chemoradiotherapy with 5-FU-based regimens, we first examined DPD mRNA expression of these patient samples. We next developed a 5-FU-resistant HNSCC cell line (HSC-3R) to clarify the association between DPD expression and 5-FU resistance. Clonogenic survival assay was performed to determine the sensitivity of HSC-3 cells and HSC-3R cells to 5-FU. DPD expression levels in parental HSC-3 and HSC-3R cell lines were then examined by Western blotting and real-time quantitative polymerase chain reaction analysis. Lastly, we performed WST-8 assay to examine the effects of 5-Chloro-2,4-dihydroxypyridine (CDHP), a 5-FU modulator to competitively inhibit DPD, on 5-FU cytotoxicity in the HSC-3 and HSC-3R cells, to evaluate if inhibition of DPD can restore the sensitivity of HNSCC cells to 5-FU. Results: Nineteen HNSCC patients who had undergone concurrent chemoradiotherapy with 5-FU-based regimens were enrolled in this study. The cut-off value for DPD mRNA expression calculated from the ROC curve was 8.53 against cancer-specific survival of these patients. The high-level DPD expression group showed significantly shorter overall and cancer-specific survival compared to the low-level DPD expression group (P=0.0018 and 0.0004, respectively). Both of protein and mRNA expression levels were greater in the HSC-3R cells than that in the HSC-3 cells. While HSC-3R cells showed 12.64-fold greater resistance to 5-FU compared with HSC-3 cells, the combination of 5-FU with CDHP had a significant inhibitory effect on 5-FU cytotoxicity in HSC-3R cells in CDHP exposure. Conclusions: In this study, we clarified that the high-level DPD expression group of HNSCC patients undergoing concurrent chemoradiotherapy with 5-FU-based regimens showed significantly shorter overall survival. The 5-FU-resistant cells established from HNSCC cells showed increased DPD expression and attenuated 5-FU resistance induced by CDHP. Our results suggested that a high level of DPD expression was correlated with 5-FU resistance and that DPD expression level might be a predictive biomarker in 5-FU-based chemoradiotherapy for HNSCC patients.
KW - 5-fluorouracil (5-FU)
KW - Chemoradiotherapy
KW - Dihydropyrimidine dehydrogenase (DPD)
KW - Head and neck squamous cell carcinoma (HNSCC)
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U2 - 10.21037/tcr.2018.03.38
DO - 10.21037/tcr.2018.03.38
M3 - Article
AN - SCOPUS:85046432151
SN - 2218-676X
VL - 7
SP - 411
EP - 419
JO - Translational Cancer Research
JF - Translational Cancer Research
IS - 2
ER -