title: High expression of SPHK1 in sacral chordoma and association with patients' poor prognosis.
abstract: Sacral chordoma is an aggressive bone tumor with a high local recurrence rate. Surgery remains the standard treatment because of its resistance to chemotherapy and radiotherapy. However, recurrence occurs frequently even after complete surgical resection. Great effort has been invested in discovering novel biomarkers and therapeutic targets. To date, the molecular mechanism is still unclear. In this study, we evaluated the expression of sphingosine kinase 1 (SPHK1) in 42 sacral chordoma samples and 16 distant normal tissue specimens by immunohistochemical staining. In addition, we analyzed its association with the clinical factors and patients' prognosis. Of all the chordoma samples, 69 % (29/42) showed high expression of SPHK1, whereas, only 19 % (3/16) of distant normal tissues expressed a high level of SPHK1 (p = 0.001). Chi-square analysis revealed that high expression of SPHK1 was significantly correlated with tumor recurrence (p = 0.019) and invasion into surrounding muscle (p = 0.005), while the data did not indicate any association with patients' gender, age, tumor location and size (p > 0.05). Kaplan-Meier survival curve and log-rank test showed that patients with high expression of SPHK1 possessed shorter continuous disease-free survival time. Conclusively, SPHK1 may become a potential biomarker for sacral chordoma in predicting its recurrence and patients' prognosis.
authors.affiliation: Department of Orthopedic Surgery, The First Affiliated Hospital of Soochow University, No. 188 Shizi Street, Suzhou, 215006, Jiangsu, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Zhang
authors.forename: Hao
authors.initials: H
authors.lastname: Chen
authors.forename: Guizhong
authors.initials: G
authors.lastname: Wu
authors.forename: Kangwu
authors.initials: K
authors.lastname: Chen
authors.forename: Huilin
authors.initials: H
authors.lastname: Yang
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000096:biosynthesis*; D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000096:biosynthesis*; D002817:Chordoma / Q000175:diagnosis / Q000378:metabolism*; D018572:Disease-Free Survival; D005500:Follow-Up Studies; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008875:Middle Aged; D011379:Prognosis; D012447:Sacrum / Q000378:metabolism* / Q000473:pathology; D013125:Spinal Neoplasms / Q000378:metabolism*; D055815:Young Adult
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D014408:Biomarkers, Tumor; C466999:SPHKAP protein, human