Identification of new fusion genes and their clinical significance in endometrial cancer

Background: Fusion genes may play an important role in tumorigenesis, prognosis, and drug resistance; however, studies on fusion genes in endometrial cancer (EC) are rare. This study aimed to identify new fusion genes and to explore their clinical significance in EC. Methods: A total of 28 patients diagnosed with EC were enrolled in this study. RNA sequencing was used to obtain entire genomes and transcriptomes. STAR-comparison and STAR-fusion prediction were applied to predict the fusion genes. Chi-square tests and Student t tests were used to verify the clinical significance with SPSS 13.0 software. Results: New fusion genes were found, and the number of fusion genes varied from 3 to 110 among all patients with EC. The type of fusion genes varied and included messenger RNA (mRNA)-mRNA, long non-coding RNA (lncRNA)-lncRNA, and lncRNA-mRNA. There were six fusion genes with high fusion rates, namely, RP11-123O10.4-GRIP1, RP11-444D3.1-.SOX5, RP11-680G10.1-GSE1, NRIP1-AF127936.7, RP11-96H19.1-RP11-446N19.1, and DPH7-PTP4A3. Further studies showed that these fusion genes are related to stage, grade, and recurrence, in which NRIP1-AF127936.7 and DPH7-PTP4A3 were found only in stage III patients with EC. DPH7-PTP4A3 was found in grades 2 and 3, and recurrent patients with EC. Conclusion: Fusion genes play an essential role in EC. Six genes that are overexpressed with high fusion rates are identified. NRIP1-AF127936.7 and DPH7-PTP4A3 might he related to stage, and DPH7-PTP4A3 he related to grade and recurrence.