1. Department of Internal Medicine, Chi Mei Medical Center, Chiali, Taiwan
2. Departments of Colorectal Surgery, Yuan's General Hospital, Kaohsiung, Taiwan.
3. Department of Health Business Administration, Meiho University, Pingtung, Taiwan
4. Division of General Surgery, Chi Mei Medical Center, Tainan, Taiwan
5. Department of Health and Nutrition, Chia Nan University of Pharmacy & Science, Tainan, Taiwan
6. Department of Internal Medicine, Chi Mei Medical Center, Tainan, Taiwan
7. Department of Leisure, Recreation, and Tourism Management, Southern Taiwan University of Science and Technology, Tainan, Taiwan
8. Department of Radiation Oncology, Chi-Mei Medical Center, Liouying, Tainan, Taiwan
9. Department of Pathology, Chi Mei Medical Center, Tainan, Taiwan
10. Department of Anesthesiology, Chi Mei Medical Center, Tainan, Taiwan
11. National Institute of Cancer Research, National Health Research Institutes, Tainan, Taiwan
12. Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan
13. Institute of Clinical Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
Purpose: Nasopharyngeal carcinoma (NPC) is a common cancer in southern China and Southeast Asia, but risk stratification and treatment outcome in NPC patients remain suboptimal. Our study identified and validated metabolic drivers that are relevant to the pathogenesis of NPC using a published transcriptome. Phosphoserine aminotransferase 1 (PSAT1) is an enzyme that is involved in serine biosynthesis, and its overexpression is associated with colon cancer, non-small cell lung cancer and breast cancer. However, its expression has not been systemically evaluated in patients with NPC.
Materials and Methods: We evaluated two public transcriptomes of NPC tissues and benign nasopharyngeal mucosal epithelial tissues that deposited in the NIH Gene Expression Omnibus database under accession number GSE34574 and GSE12452. We also performed immunohistochemical staining and assessment of PSAT1 in a total of 124 NPC patients received radiotherapy and were regularly followed-up until death or loss. The endpoints analyzed were local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), disease-specific survival (DSS), and overall survival (OS).
Results: We retrospectively evaluated 124 patients with NPC and found that high PSAT1 expression was associated with poor prognosis of NPC and indicator of advanced tumor stage. High PSAT1 expression also correlated with an aggressive clinical course, with significantly shorter DSS (HR= 2.856, 95% CI 1.599 to 5.101), DMFS (HR= 3.305, 95% CI 1.720 to 6.347), LRFS (HR= 2.834, 95% CI 1.376 to 5.835), and OS HR= 2.935, 95% CI 1.646-5.234) in multivariate analyses.
Conclusions: Our study showed that PSAT1 is a potential prognostic biomarker and higher expression of PSAT1 is associated with a poor prognosis in NPC.
Keywords: PSAT1, Nasopharyngeal carcinoma, prognosis