Journal: Oncology Reports
Article Title: Sphingosine-1-phosphate receptor 1 enhances olfactory receptor 51E1-mediated inhibition of proliferation via Src/JNK signaling in prostate cancer cells
doi: 10.3892/or.2026.9103
Figure Lengend Snippet: Co-expression of S1PR1 amplifies OR51E1-Src-JNK signaling and suppression of proliferation. (A and B) Inhibitor profiling reveals signaling pathways involved in NA-induced reduction of LNCaP cell viability. LNCaP cells were preincubated for 1 h with (A) canonical OR pathway inhibitors (SQ-22536, 100 µM; H-89, 3 µM; ESI-09, 3 µM; SU6656, 10 µM) or with (B) other, less well-characterized pathway inhibitors (SU6656, 10 µM; Dasatinib, 10 nM; SP600125, 3 µM; SB203580, 3 µM; U0126, 10 µM; AG-490, 10 µM), followed by treatment with NA for 48 h. SQ-22536 and SU6656 were included in both panels for comparison. Cell viability was measured using the CCK-8 assay. Data represent the mean ± SEM of at least three independent experiments. Statistical analysis was performed using an unpaired Student's t-test. Hash symbols (#) indicate statistical significance between vehicle- and NA-treated cells, whereas asterisks (*) indicate statistical significance between cells treated with NA alone and those co-treated with NA and the indicated inhibitors. (C) Western blot analysis of JNK activation in LNCaP and LNCaP-S1PR1 cells treated with NA for 1 h. Protein levels of p-JNK and total JNK were analyzed. (D) Effect of Src inhibition on NA-induced JNK activation. LNCaP cells were pretreated with the Src inhibitor SU6656 (10 µM) for 1 h and then treated with NA for 1 h. Protein levels of p-JNK and total JNK were assessed. Band intensities were quantified using ImageJ software. Data represent the mean ± SEM of three independent experiments. Statistical significance was determined using an unpaired Student's t-test. (E) Effect of Src inhibition on NA-mediated suppression of proliferation. LNCaP and LNCaP-S1PR1 cells were pretreated with SU6656 for 1 h, and cell viability was measured using the CCK-8 assay after NA treatment. Data represent the mean ± SEM of at least three independent experiments and were analyzed using two-way ANOVA with Tukey's multiple comparison test. (F) Effect of Src inhibition on NA-induced apoptosis. LNCaP and LNCaP-S1PR1 cells were pretreated with dasatinib (100 nM) for 1 h and then treated with NA. Apoptosis was assessed using annexin V/PI staining. Data represent the mean ± SEM of three independent experiments and were analyzed using two-way ANOVA with Tukey's multiple comparison test. ### P<0.001 and #### P<0.0001; *P<0.05, **P<0.01, ***P<0.001 and ****P<0.0001. S1PR1, sphingosine-1-phosphate receptor 1; OR51E1, olfactory receptor 51E1; NA, nonanoic acid; CCK-8, Cell Counting Kit-8; p-, phosphorylated; PI, propidium iodide; ns, not significant.
Article Snippet: LNCaP cells were obtained from the Korean Cell Line Bank, and Du145 and PC3 cells were purchased from the American Type Culture Collection.
Techniques: Expressing, Protein-Protein interactions, Comparison, CCK-8 Assay, Western Blot, Activation Assay, Inhibition, Software, Staining, Olfactory, Cell Counting