Expression of long non-coding RNA associated with radiotherapy-resistance in colorectal cancer cell lines with different radiosensitivity / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To screen long non-coding RNA (lncRNA) associated with radiosensitivity in colorectal carcinoma cell lines.</p><p><b>METHODS</b>Colony formation assay was performed in colorectal cancer cell lines HT29, SW480, RKO, Lovo and HCT116 after irradiation with different radiation doses. Radiation sensitivity of these 5 cell lines was detected through survival fraction at 2 Gy (SF2 value). High-throughput lncRNA chip was used to screen lncRNA genes with expression differences more than 2 folds among SW480, RKO and Lovo. Further experiment on the expression differences of lncRNAs selected was conducted by realtime PCR.</p><p><b>RESULTS</b>The radiosensitivity order of these 5 cell lines from low to high (SF2 value from high to low) was HT29 (0.83 ± 0.03), SW480 (0.69 ± 0.02), RKO(0.53 ± 0.02), Lovo (0.47 ± 0.05), HCT116 (0.32 ± 0.03) (P < 0.01). Five lncRNAs associated with radiation sensitivity were screened. Among them, expression levels of R05532, NR_015441, and NR_033374 were positively correlated with radiation resistance(all P < 0.01), and expression levels of the other 2 lncRNAs, NR_073156 and AA745020, were not correlated with radiation resistance of colorectal cancer cells (both P>0.05).</p><p><b>CONCLUSIONS</b>lncRNA R05532, NR_015441 and NR_033374 may be used as the predictive marker of radiosensitivity of colorectal cancer cells. Higher expression of these genes shows radiation resistance.</p>

Expression and significance of topoisomerase Ⅱα in colorectal caner / 国际外科学杂志

Objective To determine the relationship between expression of topoisomerase Ⅱ α and clinicopathological factors,overall survival in colorectal caner.Methods Expression of topoisomerase Ⅱ α was measured using EnVision immunohistochemistry in 490 colorectal cancer patients.The relationship between topoisomerase Ⅱ α expression and various clinicopathological parameters was analyzed.Kaplan-Meier analyses and multivariate analyses were used to evaluate the significance of topoisomerase Ⅱ α expression in prognosis prediction.Results Overexpression of topoisomerase Ⅱ α was found to be related with lower T stage ( P =0.042 ),lower N stage ( P =0.038 ),and possibly with lower recurrence rate ( P =0.053 ).Kaplan- Meier analyses showed that overexpression of topoisomerase Ⅱ α was related with prolonged overall survival (P =0.022 ) and prolonged disease-free survival ( P =0.036).Multivariate analyses showed that elevated serum CEA ( P ＜ 0.001 ),elevated serum CA199 ( P =0.002 ),poor differentiation ( P =0.001 ),advanced Dukes stage ( P ＜ 0.001 ) and lower expression of topoisomerase Ⅱ α( P =0.017 ) were independent predictive factors for poor prognosis.Conclusions Expression of topoisomerase Ⅱ α is a favorable predictive factor for colorectal cancer,and would be useful in prognosis prediction and treatment selection for early colorectal cancer and malignant colorectal polyps,especially when it is used in combinations with serum CEA,CA199 and differentiation.