E2F transcription factor 3 (E2F3) plays a vital role in the development of various types of
cancer. To verify whether E2F3 is a suitable
biomarker for the prognosis of
lung cancer, bioinformatics analysis was performed to determine the differential expression level of E2F3 in
lung cancer and the surrounding non-
tumor tissues, and the results were confirmed in a NSCLC cell line and a tissue microarray (TMA). The relevance of E2F3 in
non-small cell lung cancer (NSCLC) was investigated in 19 studies from the Oncomine database and confirmed in The
Cancer Genome Atlas database. In the
lung cancer cell line A549, the inhibition of E2F3
mRNA expression level led to decreased
tumor cell viability and cell migration, which was determined by a Cell Counting Kit-8 and wound healing assays, respectively. Immunohistochemistry analyses of E2F3, Bcl-2, Bax and
caspase-3 were performed in the NSCLC TMA (n=50). The assessment of TMA detected the increase of E2F3
protein expression level in the
tumor tissues, as compared with that in the non-
tumor tissues, which was also correlated with the increase in expression of Bcl-2 in
tumors. Analysis of the clinical data from patients with NSCLC revealed that the overexpression of E2F3 was associated with early lymphatic spreading, and poor patient survival time. The OncomiR website was used to predict the E2F3 upstream
microRNAs and determine their prognostic value in patients with NSCLC. The results from the present study revealed that E2F3 was overexpressed at both the transcriptional and translational levels in NSCLC tissues, as compared with that in non-
tumor tissues. The overexpression of E2F3 was associated with the upregulation of the anti-apoptotic factor, Bcl-2, which may contribute to uncontrolled
tumor growth. Thus, E2F3 was shown to have important oncogenic properties in the development of NSCLC, and it may become a potential
biomarker for patients with NSCLC.