RESUMO
Metastasis is the primary cause of mortality in patients with nonsmall cell lung cancer (NSCLC). Actin cytoskeletal reorganization is usually accompanied by the epithelialmesenchymal transition (EMT)induced invasion and metastasis of cancer cells. In the present study, expression levels of the actinassociated protein cofilin1 and of the pivotal EMT molecule Twist1 were determined in NSCLC tissues. Using lung cancer tissue arrays, the identification of 67.4% of tissue spots that exhibited reciprocal levels of cofilin1 and Twist1 was achieved by immunohistochemical (IHC) staining. This reciprocal expression pattern was also detected in 21 out of 25 clinicopathological NSCLC tissue sections, and in 10 out of 15 NSCLC cell lines. In addition, high levels of cofilin1 and low levels of Twist1 accounted for 80 and 71.5% of the reciprocal expression pattern in tissue arrays and clinicopathological tissue samples, respectively. This pattern was also detected in normal lung tissues, stage I and II lung cancer tissues, and adenocarcinoma subtypes of NSCLC tissues. Although cofilin1 and Twist1 were expressed inversely, a positive correlation of these two proteins was present in normal lung tissues and lung tumor tissues. Furthermore, enforced expression of cofilin1 suppressed the expression level of Twist1 in NSCLC H1299 cells. An online KaplanMeier survival analytic tool allowed access to a public microarray dataset with a maximum of 1,926 NSCLC samples. The analysis revealed that high expression levels of both cofilin1 (CFL1) and Twist1 (TWIST1) genes were associated with decreased survival of NSCLC patients, notably with regard to the adenocarcinoma subtype. The analysis was conducted using the multivariate Cox regression model. Although the reciprocal association of the expression levels of cofilin1 and Twist1 with the survival rate of NSCLC patients requires additional information, it may be a significant indicator of the progression of NSCLC.
