Cysteinyl Leukotriene Receptor Antagonists Modulate The Differentiation Of Neuroblastoma SK-N-SH Cells

AIM: To determine whether cysteinyl leukotriene receptor agonist LTD4 and cysteinyl leukotriene receptor 1 (CysLT₁ receptor) antagonists, praniukast and montelukast, affect the differentiation of human neuroblastoma SK-N-SH cells.METHOD: We observed SK-N-SH cell morphological changes induced by LTD₄(10^-12～10^-8mol/L), pranlukast (10^-8～10^-5 mol/L), montelukast (10^-8～10^-5 mol/L) and LTD₄ (10^-8mol/L) + pranlukast (10^-8～10^-5mol/L). Retinoid acid (RA) was used as the positive control. The expressions of CysLTi and CysLT2 receptors were detected by immunoblotting analysis, and the expression of microtubule-associated protein-2 (MAP-2), a neuron marker, was detected by fluorescent immunostaining.RESULTS: (1) The immunoblotting results showed that SK-N-SH cells expressed CysLT₁ receptor moderately, and CysLT₂ receptor highly. (2) CysLT receptor agonist LTD₄(10^-12～10^-8 mol/L) had no obvious effect on the differentiation of neuroblastoma SK-N-SH cells. (3) RA and pranlukast caused a concentration- and time-dependent induction of SK-N-SH cell differentiation. After treatment with pranlukast (10^-8～10^-5 mol/L), cell morphology changed and the prominence was exserted. At 5 days of differentiation induced by pranlukast, we observed the compaction of the cell bodies and the outgrowth of neuritis. Treatment with 10^-5 mol/L pranlukast had a more evident effect on the cell morphological changes. Montelukast inducing cell differentiation at first day had a stronger effect than that of pranlukast. (4) Combination of LTD4 and pranlukast also induced SK-N-SH cell differentiation; the effect was more powerful than pranlukast alone. Pranlukast at 10^-5 mol/L promoted the growth of neuritis at 1st day, and it at 10^-8 mol/L also had this effect at the fifth day. (5) The immunostaining results showed that MAP-2 was distributed in the cell bodies in control or pranlukast-treated cells; it was distributed in both the cell bodies and neuritis in RA-treated cells. Pranlukast increased the numbers of MAP-2-possitive cells.CONCLUSION: The CysLT₁ receptor agonist LTD₄ can not affect SK-N-SH cell morphological changes, while the CysLT₁ receptor antagonists, pranlukast and montelukast, modulate the differentiation of SK-N-SH cells.