The Application of FOXO1A Expression Predicts Aggressive Behavior and Poor Prognosis in Gliomas

Forkhead box, class O, 1A (FOXO1A) is an important factor related to some human malignancies. We tested the association between FOXO1A cytoplasmic expression and World Health Organization grading system in primary brain tumors (PBTs). First of all, Western blot analysis was also performed in normal brain tissue and U87MG, LN229, GBM8401, and U118MG glioma cell lines protein lysates. Then, in order to realize FOXO1A gene expression in gliomas, U87MG, LN229, GBM8401 mRNA were applied to performed quantitative reverse transcription polymerase chain reaction (RT-PCR). At last, the immunohistochemical (IHC) analysis of FOXO1A was performed in 8 non-neoplastic brain tissues and 126 PBTs. The immunostain scores were obtained as the degree of cytoplasmic FOXO1A intensity multiplied by the percentage of positively stained tumor area. On the basis of the results of these in vitro studies, marked increase FOXO1A protein and mRNA expressions in glioma cell lines than in normal human tissue. On the view point of IHC stains, the average immunostain score of FOXO1A in all PBTs was significantly higher than non-neoplastic brain tissues. In addition, the immunostain scores of FOXO1A in high grade were higher than low-grade gliomas. Furthermore, higher cytoplasmic expression of FOXO1A might indicate the shorter overall survival rate in gliomas. Furthermore, FOXO1A expression was associated with isocitrate dehydrogenase I /2, ATRX, and p53 mutation by IHC staining. Therefore, the application of FOXO1A IHC stain might have some benefits to improve diagnostic accuracy, predict tumor progression, and evaluate survival time in glioma patients.