Correlations of cofilin1 and phosphorylation at Ser3 site with sensitivity of elderly patients with non-small cell lung cancer to radiotherapy

Abstract Background: To explore the correlations of cofilin1 (CFL1) and phosphorylation level of locus serine residue at position 3 (Ser3) with the sensitivity of elderly patients with non-small cell lung cancer (NSCLC) to radiotherapy. Methods: A total of 102 eligible patients treated from June 2013 to April 2015 were selected. The cases of complete remission and partial remission were included into radiotherapy-sensitive group (n=55), while those of stable disease and progressive disease were enrolled into radiotherapy-resistant group (n=47). Before treatment, tissues were collected to detect the expressions of CFL1 and CFL1 (phospho S3) by immunohistochemistry. The survival time and rate were recorded during follow-up. Results: Compared with the radiotherapy-sensitive group, the radiotherapy-resistant group had advanced tumor-node-metastasis (TNM) stage and higher lymph node metastasis rate (P=0.000, 0.000). Compared with the tissues with negative CFL1 expression, the tissues with positive CFL1 expression had advanced TNM stage and higher lymph node metastasis rate (P=0.013, 0.000). The positive expression rate of CFL1 in the radiotherapy-resistant group was higher than that of the radiotherapy-sensitive group, whereas the positive expression rate of CFL1 (phospho S3) in the former was lower (P=0.000, 0.000). Lymph node metastasis, high CFL1 expression, and low CFL1 (phospho S3) expression were independent predictors for resistance to radiotherapy (P=0.001, 0.006, 0.003). In the radiotherapy-sensitive group, the patients with negative CFL1 expression and positive CFL1 (phospho S3) expression had long progression-free survival and high 5-year survival rate (P=0.000, 0.000). Conclusion: The sensitivity to radiotherapy of elderly NSCLC patients is correlated negatively with CFL1 and positively with phosphorylation at locus Ser3. CFL1 and phosphorylation at locus Ser3 are independent predictors for sensitivity to radiotherapy.