Objective Abnormal activation of mitogen-and stress-activated kinase (MSK1) plays an important role in the development of various cancers.This study was to explore the effect of small interfering RNA (siRNA)-mediated MSK1-silencing on the proliferation of human nasopharyngeal carcinoma (NPC) cells and its underlying mechanism.Methods The siRNA vector targeting MSK1 was constructed and transfected into CNE2 cells, and the NPC cell line stably expressing MSK1 was established.Then the cells were divided into a blank control (without transfection of the plasmid), a negative control (with stable transfection of the negative control plasmid), and an experimental group (with stable transfection of the positive recombinant plasmid).The expressions of MSK1 mRNA and protein were detected by real-time quantitative PCR and Western blot, respectively, the proliferation of the cells determined by CCK-8 and colony formation assays, the cell cycles analyzed by flow cytometry, the level of histone H3 phosphorylation at Ser10 examined by Western blot, and The transcriptional activity and expression of the c-jun protein measured by dual-luciferase reporter gene assay and Western blot.Results Compared with the blank control, the inhibition rates of cell proliferation at 48, 72 and 96 hours were significantly reduced in the experimental group (P<0.05), and so were the colony formation ability of the cells (P<0.01) and the expression and transcriptional activity of the c-jun protein (P<0.05).In comparison with the negative control, the experimental group showed significant decreases in the rate of cell growth after 24 hours, the inhibition rates of cell proliferation at 48, 72 and 96 hours (P<0.05), the number of formed colonies ([221.00±20.08] vs [99.67±15.57] / 300 cells, P<0.01), the proportion of S-phase cells (P<0.01), and the expression of the c-jun protein in the CNE2 cells ([100.00±0.00] vs [48.77±10.71] %, P<0.05), but a remarkable increase in the percentage of G0/G1-phase cells (P<0.01).Furthermore, histone H3 phosphorylation at Ser10 was markedly reduced (P<0.01) but no significant change was observed in the expression of the total c-jun protein in the experimental group.Conclusion Knockdown of MSK1 using siRNA can significantly inhibit the growth and proliferation of CNE2 cells, which may be closely related to the decreased phosphorylation of histone H3 and subsequently down-regulated transcriptional activity of c-jun.

OBJECTIVE：To study the effects of Modified liuwei dihuang decoction on kidney/bone injury of chronic kidney disease-mineral and bone disorder（CKD-MBD）model rats. METHODS ：The male SD rats were randomly divided into normal group（n＝10），high phosphorus group （n＝30），model group （n＝30），calcitriol group （positive control ，0.09 μg/kg，n＝30）， Modified liuwei dihuang decoction group （10 g/kg by crude drug ，n＝30）. CKD-MBD model was established by high phosphorus and adenine diet for 6 weeks. After modeling ，normal group and model group were given normal diet/high phosphorus diet and intragastric administration of water. Administration groups were fed with normal diet and given corresponding solution intragastrically（water as solvent ），0.1 mL/kg，once a day ，for consecutive 6 weeks. Blood sample of rats in the normal group were collected ，and they were sacrificed after the last administration. Blood sample of 10 rats in each other group were collected ， and they were sacrificed at 2，4 and 6 weeks after administration. The contents of blood urea nitrogen （BUN），serum creatinine （Scr），calcium，phosphorus，iPTH，FGF-23，RANKL and osteocalcin in serum were detected in each group. The bone mineral density（BMD）of femoral was measured ，the morphological changes of renal tissue and bone tissue were observed ，and the percentage of renal tubular injury and the score of renal interstitial fibrosis were calculated. RESULTS ：Compared with normal group，above indexes in high phosphorus group had no significant change at different time points （P＞0.05）. There was no abnormal change in renal/bone tissue. Compared with high phosphorus group at the same time point ，the contents of BUN ，Scr， phosphorus，iPTH，FGF-23，RANKL and osteocalcin in serum ，the percentage of renal tubular injury and the score of renal interstitial fibrosis in the model group were significantly increased ，while the contents of calcium in serum and the BMD of femoral were significantly decreased （P＜0.05 or P＜0.01）. The renal tissue showed diffuse fibrosis. The width of trabecular bone was increased and the number of osteoblasts was decreased. Compared with the model group at the same time point ，the contents of BUN（except for Modified liuwei dihuang decoction group after 2 weeks of administration ），Scr，serum phosphorus ，iPTH， FGF-23，RANKL and osteocalcin ，the percentage of renal tubular injury and the score of renal interstitial fibrosis in Modified liuwei dihuang decoction group and calcitriol group were decreased significantly at each time point ；serum calcium content and BMD（except for 2 weeks of administration ）were significantly increased （P＜0.05 or P＜0.01），and the pathological changes of renal/bone tissue were significantly improved ；there was no statistical significance in above indexes between Modified liuwei dihuang decoction group and calcitriol group （P＞0.05）. CONCLUSIONS ：Modified liuwei dihuang decoction can improve kidney/ bone injury of CKD-MBD model rats ，and improve BMD and regulate disorder of calcium and phosphorus metabolism.