Bioinformatics analysis of key differentially expressed genes in well and poorly differentiated endometrial carcinoma.

Endometrial carcinoma (EC) is one of the most common gynecological malignancies. The malignant degree increases between grade (G)1 and G3, and EC of G3 usually presents a high recurrence rate and poor prognosis. Therefore, the present study aimed to examine the principal genes associated with the degree of differentiation in EC. The microarrays GSE17025, GSE24537 and GSE35784, representing data of Type I EC samples of G1 and G3, were downloaded from the Gene Expression Omnibus. The differentially expressed genes (DEGs) and differentially expressed micro (mi)RNAs (DEMs) were identified, followed by functional enrichment analyses and interaction network construction. In total, 83 upregulated and 130 downregulated DEGs with the same expression trends in two mRNA datasets were screened. The upregulated DEGs were primarily enriched in 'mitotic cell cycle process', 'cell cycle process' and 'mitotic cell cycle'; while the downregulated DEGs were enriched in 'cellular component assembly involved in morphogenesis', 'cell projection organization' and 'microtubule‑based movement'. From the protein‑protein interaction network, DNA topoisomerase IIα, kinesin family member 11, cyclin B1 and BUB1 mitotic checkpoint serine/threonine were identified as foremost hub genes. One module was extracted and involved in 'mitotic cell cycle process' and 'cell cycle process'. Based on the analysis of DEMs and the miRNA‑target regulatory network, miRNA‑9 may be the most important upregulated DEM, and the DEGs forkhead box P1 and cyclin E1 may serve vital roles in the differentiation of EC. In conclusion, principal genes were identified that may be determinants of the carcinogenesis of poorly differentiated EC, which may facilitate the examination of potential molecular mechanisms. These genes may additionally help identify candidate biomarkers and novel therapeutic targets for poorly differentiated EC.