Novel protein pp3501 mediates the inhibitory effect of sodium butyrate on SH-SY5Y cell proliferation

Abstract Sodium butyrate, a new potential therapeutic drug, improves the efficacy of chemo‐ and immunotherapy of cancer under unknown mechanisms. A novel gene pp3501 is significantly induced in SH‐SY5Y neuroblastoma cells upon sodium butyrate treatment. Therefore, this study has cloned pp3501 cDNA by RT‐PCR and generated its recombinant fusion protein and anti‐serum subsequently. The pp3501 protein localized mainly in the nucleus, as detected by immunocytochemistry and the expression of pp3501‐EGFP fusion protein. pp3501 inhibited the proliferation of SH‐SY5Y cells, arrested the cell cycle at G1 phase, and sensitized the SH‐SY5Y cells to sodium butyrate treatment. These results provide a new mechanism of sodium butyrate inhibiting cancer cell proliferation as well as a new avenue for the future research on the functions of pp3501. J. Cell. Biochem. 113: 2696–2703, 2012. © 2012 Wiley Periodicals, Inc.