Abstract 4897: Genetic variants and expression of AEG-1 in relation to clinical outcome and radiotherapy response in colorectal cancer patients and cell lines

• Published in: Cancer research (Chicago, Ill.) Ill.), 2014-10, Vol.74 (19_Supplement), p.4897-4897
• Main Authors: Gnosa, Sebastian, Brodin, Veronika Patcha, Ticha, Ivana, Adell, Gunnar, Arbman, Gunnar, Zhang, Hong, Sun, Xiao-Feng
• Format: Article
• Language: English
• ISSN: 0008-5472; 1538-7445
• DOI: 10.1158/1538-7445.AM2014-4897

Background: Colorectal cancer (CRC) is the third most common cancer in men and the second in woman worldwide. The therapy of CRC has been critically improved during the past two decades, but the treatment response varies significantly between different treatments and patients. Therefore it is of need to search for biomarkers for more suitable prognosis and treatment. The aim of this study was to investigate genetic variants of the astrocyte elevated gene-1 (AEG-1), its expression in CRC patient samples and colon cancer cell lines and the potential correlation to clinicopathological variables and treatment response. Materials and Methods: We analysed genetic variants and the mRNA and protein expression of AEG-1 in 593 CRC patient samples by direct Sanger sequencing, qPCR and immunohistochemistry. Of the patients, 158 rectal cancer patients were enrolled in the Swedish clinical trial of preoperative radiotherapy (RT). AEG-1 expression in response to γ-irradiation was analysed by Western blot in 5 colon cancer cell lines. We inhibited the AEG-1 expression by siRNA in the cell lines, and their survival was analysed after γ-irradiation. Results: By direct sequencing we found 29 variants, of which 12 were novel. Six of the variants were exonic and 23 intronic. The variant c.1353G>A, rs2331652 was found only in 4 samples and the variant c.1679-6 T>C in only one sample. In the cell lines KM12C, KM12SM and KM12L4a we found a deletion in exon 4 (c.595_598delAGAG). AEG-1 mRNA and protein expression revealed a significant increased AEG-1 expression in the primary tumors and metastases compared to the normal mucosa in all patient cohorts (p