SLC6A3 as a potential circulating biomarker for gastric cancer detection and progression monitoring

Background: Gastric cancer is a malignant tumor originating from the gastric mucosal epithelium, with no obvious symptoms at the early stage. The dopamine transporter gene (SLC6A3) is involved in the metabolism of dopamine and catecholamine and is a potential gene for Parkinson's disease and alcoholism. But the role of SLC6A3 in gastric cancer is still unknown. The aim of our study is to investigate the potential diagnostic value of SLC6A3 on gastric cancer. Methods: Quantitative real-time PCR (RT-qPCR) was used to detect the expression of SLC6A3 in clinical samples and cells. A total of 246 samples were enrolled in this study (26 pairs of tissue samples; Serum of 113 patients with gastric cancer, 51 polyps patients and 56 healthy controls). The diagnostic value of SLC6A3 was evaluated by the ROC curve and analyzed the changes of SLC6A3 expression before and after surgery. The prognostic value, interacting proteins and related pathways of SLC6A3 were evaluated by TCGA analysis in UALCAN database (http://ualcan.path.uab.edu/). Results: The expression level of SLC6A3 in gastric cancer was significantly higher than that in controls. Further, the proportion under the ROC curve (AUC) for SLC6A3, CEA and CA19-9 was 0.818 (95 % confidence interval [CI]: 0.754 to 0.883, P < 0.001), and the expression level of SLC6A3 in the serum of patients with gastric cancer decreased significantly after surgery (P < 0.001). Bioinformatic enrichment analysis of SLC6A3 displayed the relevant metabolic pathways involved in its interacting proteins. Conclusion: SLC6A3 is involved in the occurrence and development of gastric cancer and can be used as a potential diagnostic indicator for gastric cancer.

Automated summary

The study revealed that the expression level of SLC6A3 is significantly elevated in gastric cancer and has potential diagnostic value. Bioinformatic analysis of SLC6A3 showed its involvement in multiple metabolic pathways related to gastric cancer.