DUSP facilitates RPMI8226 myeloma cell aging and inhibited TLR4 expression.

Objective: Myeloma severely threatens public health, and molecular targeting treatment becomes the future perspective. Dual specificity phosphatases (DSUP) protein has multiple functions including modulating cell proliferation, differentiation, aging, and apoptosis. Whether DUSP can regulate myeloma cell is unclear. This study thus aimed to investigate the effect of DUSP on myeloma cell line RPMI8226 cell aging and provide evidence for the clinical treatment of myeloma.
Materials and Methods: H2O2-induced aging model of myeloma cell line RPMI8226 was generated. DUSP over-expression plasmid or specific siRNA was transfected by liposome. Western blot was used to detect the expression of DUSP in RPMI8226 cells. Cell aging condition was evaluated by β-galactosidase assay. Aging proteins P53 and P16 expression levels, the activation of TLR4 signal pathway were tested by immunoblotting. TLR4 signal pathway was then suppressed by Verteporfin for testing RPMI8226 cell aging.
Results: Growing levels of DUSP, aging proteins P53 and P16, with inhibition of TLR4 signal pathway were found in the H2O2-induced aging model of myeloma cell line RPMI8226. Transfection of DUSP over-expression plasmid or siRNA potentiated or inhibited the aging of RPMI8226 cells induced by H2O2 and suppressed or enhanced TLR4 signal pathway, respectively. Verteporfin, an inhibitor of TLR4, increased the level of P53 and aging of RPMI8226 cells.
Conclusions: DUSP facilitates H2O2-induced aging of myeloma cell line RPMI8226 and suppresses TLR4 expression, which provides academic basis for clinical intervention.