The aim of this study was to determine whether Krüppel-like factor 5(KLF5) expression in pre-irradiation tumor biopsies is a useful predictive marker of tumor response in patients with rectal cancer
This study included 60 human colon tumor pre-irradiation specimens. Expression was studied by immunohistochemistry(IHC) using scoring system(0-15). Functional roles of KLF5 were analysed by over-expression of the protein in colon cancer cell line. Protein interactions were studied by stress induction such as chemo or radiation and MTT assays.
Complete remission was achieved by 9(18%) patients. Tumor regression was significantly related with p53 and KLF5(p = 0.021,p = 0.004,respectfully). The KLF5 IHC score significantly correlated with KRAS mutation status(5.92 ± 2.54 vs 8.44 ± 1.94,p = 0.006),and pCR(4.11 ± 2.61 vs 6.68 ± 2.43,p = 0.005). In HCT 116 cell line, KLF5 protein was significantly increased after radiation therapy, suggesting that KLF5 via cyclin D1, b-catenin. HCT 116 with KLF5 overexpression exhibited significantly better cell viability compared to control cells in MTT assay.
Overexpression of KLF5 might be predictive of poor tumor regression after preoperative CRT. Our study suggests IHC of KLF5 as a possible biomarker to predict complete remission and T-down staging. Our study suggests KLF5 has a role to get resistance to chemo-radiation therapy in rectal cancer treated preoperative CRT.
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All authors have declared no conflicts of interest.