Up-regulation of SUMO1 pseudogene 3 (SUMO1P3) in gastric cancer and its clinical association.

Long noncoding RNAs (lncRNAs) play crucial roles during cancer occurrence and progression. The pseudogene-expressed lncRNA is one major type of lncRNA family. However, their association with cancers is largely unknown. In this study, we focused on small ubiquitin-like modifier (SUMO) 1 pseudogene 3, SUMO1P3. Gastric cancer tissues and adjacent nontumor tissues were collected from 96 patients with gastric cancer. The SUMO1P3 levels were detected by quantitative reverse transcription-polymerase chain reaction. Then, the association between the level of SUMO1P3 in gastric cancer tissues and the clinicopathological features of patients with gastric cancer was further analyzed. A receiver operating characteristic curve was constructed for differentiating patients with gastric cancer from patients with benign gastric diseases. The results showed that SUMO1P3 was significantly up-regulated in gastric cancer tissues compared with paired-adjacent nontumorous tissues (p < 0.01). Its expression level was significantly correlated with tumor size (p = 0.003), differentiation (p = 0.002), lymphatic metastasis (p = 0.001), and invasion (p = 0.039). The area under the ROC curve of SUMO1P3 was up to 0.666. These results indicated, for the first time, that pseudogene-expressed lncRNA SUMO1P3 may be a potential biomarker in the diagnosis of gastric cancer.