Lentinan suppresses the progression of neuroblastoma by inhibiting FOS-mediated transcription activation of VRK1 to stabilize p53 protein

Neuroblastoma (NB) is a common malignant and solid pediatric tumor with unfavorable prognosis. Although studies have shown the anti-tumor efficacy of lentinan (LNT), molecular mechanism that contribute to the anti-tumor effect on NB remains unclear. The aim of this study is to unmask the anti-tumor role of LNT in NB and the specific molecular mechanism. At first, the in vivo experiments were conducted and the results indicated that LNT could suppress tumor growth in NB. Subsequent cellular functional assays unveiled that LNT treatment could efficiently decrease NB cell viability, induce cell cycle stagnation at G0/G1 phase, increase the apoptosis rate, and weaken the migrating and invasive abilities. Furthermore, LNT resulted in a significant downregulation of FOS expression. FOS overexpression recovered the growth, migration and invasion of NB cells suppressed by LNT treatment. Mechanism investigations revealed that FOS interacted with JUND to transcriptionally activate VRK1. Moreover, VRK1 downregulated p53 protein via inducing the phosphorylation of p53 at site 291-393. In summary, this study reveals a novel molecular pathway by which LNT exerts tumor-suppressing functions in NB.