Overexpression of the PSAT1 Gene in Nasopharyngeal Carcinoma Is an Indicator of Poor Prognosis.
OBJECTIVE
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.


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.
1. Department of Internal Medicine, Chi Mei Medical Center, Chiali, Taiwan.
Kuang-Ming
KM
Liao
2. Departments of Colorectal Surgery, Yuan's General Hospital, Kaohsiung, Taiwan.; 3. Department of Health Business Administration, Meiho University, Pingtung, Taiwan.
Tung-Bo
TB
Chao
4. Division of General Surgery, Chi Mei Medical Center, Tainan, Taiwan; 5. Department of Health and NutritionChia Nan University of Pharmacy & Science, Tainan, Taiwan.
Yu-Feng
YF
Tian
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.
Ching-Yih
CY
Lin
8. Department of Radiation Oncology, Chi-Mei Medical Center, Liouying, Tainan, Taiwan.
Sung-Wei
SW
Lee
1. Department of Internal Medicine, Chi Mei Medical Center, Chiali, Taiwan.
Hua-Ying
HY
Chuang
9. Department of Pathology, Chi Mei Medical Center, Tainan, Taiwan.
Ti-Chun
TC
Chan
9. Department of Pathology, Chi Mei Medical Center, Tainan, Taiwan.
Tzu-Ju
TJ
Chen
10. Department of Anesthesiology, Chi Mei Medical Center, Tainan, Taiwan.
Chung-Hsi
CH
Hsing
6. Department of Internal Medicine, Chi Mei Medical Center, Tainan, Taiwan.
Ming-Jen
MJ
Sheu
9. Department of Pathology, 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.
Chien-Feng
CF
Li
Nasopharyngeal carcinoma; PSAT1; prognosis