Identification of differentially expressed genes related to radioresistance of human esophageal cancer cells.
OBJECTIVE
Radioresistant cells in esophageal cancer is one of the important reasons for the local failure of radiotherapy. In recent years, some researchers used gene chip technology to screen the differentially expressed genes between parental and radioresistant human esophageal cancer cells. But there were some problems in these studies, for example comparing cells at only one time interval, and genetic background not matching. In this study, we selected 3 different pairs of parental and radioresistant human esophageal cancer cells, and compared the gene expression profiles by cDNA microarray at 3 time intervals to identify and analyze the differentially expressed genes between parental and radioresistant human esophageal cancer cells.


METHODS
We compared the gene expression profiles between parental cells (TE13, Seg-1, Kyse170) and radioresistant cells (TE13R, Seg-1R, Kyse170R) before, and at 8 h and 24 h after irradiation with a cDNA microarray consisting of 48 000 genes (Human Genome). We identified differentially expressed genes by Pathway and GO analyses, and verified the differentially expressed genes LEF1 and CTNNB1 by RT-PCR.


RESULTS
A total of 460, 451, and 397 differentially expressed genes were found before, and at 8 h and 24 h after irradiation. After Pathway and GO analyses, 14 differentially expressed genes, participating in cell growth, apoptosis, cell cycle regulation, gene repair and signal transmission, were selected to further research. LEF1 and CTNNB1 were verified by RT-PCR, and the results were consistent with those of cDNA microarray.


CONCLUSIONS
The WNT signal pathway may be an important pathway participating in the formation of radioresistance of esophageal cancer cells. LEF1 and CTNNB1 may be the important genes causing the esophageal cancer cell radioresistance.
Li
Hong-Zhen
HZ
Department of Radiation Oncology, Peking University First Hospital, Beijing 100034, PR China.
Gao
Xian-Shu
XS
Xiong
Wei
W
Zhao
Jing
J
Zhang
Hai
H
Zhou
De-Min
DM
D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor / Q000528:radiation effects; D004938:Esophageal Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051821:Lymphoid Enhancer-Binding Factor 1 / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D011836:Radiation Tolerance; D059467:Transcriptome; D060449:Wnt Signaling Pathway / Q000528:radiation effects*; D051176:beta Catenin / Q000378:metabolism
C495270:CTNNB1 protein, human; C497573:LEF1 protein, human; D051821:Lymphoid Enhancer-Binding Factor 1; D051176:beta Catenin