Behavior of sphingosine 1-phosphate receptor 4 gene expression in patients with neuroblastoma

Sphingosine 1-phosphate receptor 4 (S1P4), which induces cellular migration and prevents apoptosis, was investigated in patients diagnosed with neuroblastoma in our study. The study included 37 neuroblastoma patients and 25 healthy children. After RNA isolation, cDNA were performed and S1P4 gene expression levels were measured in leukocytes. S1P4 gene expression levels presented as mean ± SD were high in the study group. The difference was statistically significant between neuroblastoma patients (0.0387±0.0647) and healthy children (0.0366±0.0238) for S1P4 gene expression levels (p=0.028). Patients given no chemotherapy yet and and those who already completed chemotherapy showed no significant difference statistically (p=0.886). While decreased S1P4 gene expression levels (0.0188±0.0069) were seen in patients receiving maintenance therapy, patients completed chemotherapy had increased S1P4 gene expression levels (0.0322±0.0303). The difference was meaningful (p=0.048). Although S1P4 gene expression levels (0.0310±0.0201) estimated before the beginning of chemotherapy were higher than that of maintenance phase (0.0188±0.0069), the difference was not significant (p=0.158). Higher S1P4 gene expression levels were remarkable in neuroblastoma patients. The suppression of S1P4 gene expression levels during maintenance phase and the increasing of expression in following up without chemotherapy could bring to mind that the chemotherapy could cause to decreased cell migration and/or induction of apoptosis. The effect of S1P4 on the tumor progression and the association with chemotherapy should be investigated in cancer cases.