title: Role of miR-100 in the radioresistance of colorectal cancer cells.
abstract: The prognosis of radioresistant colorectal cancer (CRC) is generally poor. Abnormal expression of microRNAs (miRNAs) is involved in the radiosensitivity of various tumor cells as these RNAs regulate biological signaling pathways. However, radioresistance-associated miRNAs in CRC have not yet been identified. In this study, we filtered out HCT116 and CCL-244 from seven CRC cell lines that showed the highest difference in radiosensitivity in a clonogenic assay. MiRNA sequencing identified 33 differentially expressed miRNAs (13 up-regulated and 20 down-regulated) in CCL-244 and 37 in HCT116 (20 up-regulated and 17 down-regulated) cells. MiR-100 was significantly down-regulated in CCL-244 cells after X-ray irradiation but not in HCT116 cells. Quantitative real-time PCR showed that the expression of miR-100 in CRC tissues was significantly lower than that in normal tissues. Thus, miR-100 seems to be involved in the radioresistance of CCL-244 cells. MiR-100 up-regulation sensitized CCL-244 cells to X-ray irradiation, which probably led to apoptosis and DNA double-strand breaks in these. In conclusion, to our knowledge, this is the first study to show that miR-100 may play an important role in regulating the radiosensitivity of CRC, and it may act as a new clinical target for CRC radiotherapy.
authors.affiliation: Department of General Surgery, The Second Affiliated Hospital of Soochow University No. 1055, Suzhou 215004, China.
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Yang
authors.affiliation: Department of General Surgery, The First People's Hospital of Taicang City, Taicang Affiliated Hospital of Soochow University No. 58, Taicang, Suzhou 215400, China.
authors.forename: Xiao-Hui
authors.initials: XH
authors.lastname: Xu
authors.affiliation: School of Radiation Medicine and Protection and Jiangsu Provincial Key Laboratory of Radiation Medicine and Protection, Medical College of Soochow University Suzhou 215123, China ; Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions and School for Radiological and Interdisciplinary Sciences (RAD-X), Soochow University Suzhou 215123, China.
authors.forename: Shu-Yu
authors.initials: SY
authors.lastname: Zhang
authors.affiliation: Department of General Surgery, The Second Affiliated Hospital of Soochow University No. 1055, Suzhou 215004, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of General Surgery, The Second Affiliated Hospital of Soochow University No. 1055, Suzhou 215004, China.
authors.forename: Chun-Gen
authors.initials: CG
authors.lastname: Xing
authors.affiliation: Department of General Surgery, The Second Affiliated Hospital of Soochow University No. 1055, Suzhou 215004, China.
authors.forename: Gan
authors.initials: G
authors.lastname: Ru
authors.affiliation: Department of General Surgery, The Second Affiliated Hospital of Soochow University No. 1055, Suzhou 215004, China.
authors.forename: Hong-Tao
authors.initials: HT
authors.lastname: Xu
authors.affiliation: School of Radiation Medicine and Protection and Jiangsu Provincial Key Laboratory of Radiation Medicine and Protection, Medical College of Soochow University Suzhou 215123, China ; Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions and School for Radiological and Interdisciplinary Sciences (RAD-X), Soochow University Suzhou 215123, China.
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Cao
keywords: Colorectal cancer; miR-100; miRNA profiling; radioresistance; radiosensitivity