CCR6 Is a Predicting Biomarker of Radiosensitivity and Potential Target of Radiosensitization in Rectal Cancer.
- Author:
Hui CHANG
1
;
Jia wang WEI
;
Ya lan TAO
;
Pei rong DING
;
Yun fei XIA
;
Yuan hong GAO
;
Wei wei XIAO
Author Information
- Publication Type:Original Article
- Keywords: CCR6; Rectal neoplasms; Radioresistance; DNA damage
- MeSH: Cell Line; Colorectal Neoplasms; DNA Damage; Genes, vif; Humans; Neoplasm Metastasis; Polymerase Chain Reaction; Radiation Tolerance*; Radiation, Ionizing; Radiotherapy; Rectal Neoplasms*; RNA Interference; RNA, Messenger; Sequence Analysis, RNA; Therapeutic Uses
- From:Cancer Research and Treatment 2018;50(4):1203-1213
- CountryRepublic of Korea
- Language:English
- Abstract: PURPOSE: This study aimed to explore the functions and mechanisms of C-C motif chemokine receptor 6 (CCR6), a gene associated with progression and metastasis of colorectal cancer (CRC), in radiosensitivity of rectal cancer (RC). MATERIALS AND METHODS: RNA sequencing and immunohistochemical analysis on CCR6 expression were performed in pretreatment tissues of RC patients exhibiting different therapeutic effects of radiotherapy. Colonogenic survival assay was conducted in different CRC cell lines to assess their radiosensitivity. And the impact of CCR6 expression on radiosensitivity was validated through RNA interference. The DNA damage repair (DDR) abilities of cell lines with different CCR6 expression were evaluated through immunofluorescence-based γH2AX quantification. RESULTS: The CCR6 mRNA level was higher in patients without pathologic complete remission (pCR) than in those with pCR (fold changed, 2.11; p=0.004). High-level expression of CCR6 protein was more common in the bad responders than in the good responders (76.3% vs. 37.5%, p < 0.001). The CRC cell lines with higher CCR6 expression (LoVo and sw480) appeared to be more radioresistant, compared with the sw620 cell line which had lower CCR6 expression. CCR6 knockdown made the LoVo cells more sensitive to ionizing radiation (sensitization enhancement ratio, 1.738; p < 0.001), and decreased their DDR efficiency. CONCLUSION: CCR6 might affect the RC radiosensitivity through DDR process. These findings supported CCR6 as a predicting biomarker of radiosensitivity and a potential target of radiosensitization for RC patients.
