Effect of Tyrosine Phosphorylation Sites of Oncogenic Protein NPM-ALK on Cell Cycle and Its Related Mechanisms / 中国实验血液学杂志

<p><b>UNLABELLED</b>Objective：To explore the effect of tyrosine phosphorylation sites Tyr644 and Tyr664 in oncogenic protein NPM-ALK on cell cycle and its related mechanisms.</p><p><b>METHODS</b>Transiently transfected 293T cells and stably transfected Jurkat cells were used for analysis of cell cycle and protein after the transfection with the constructed recombinant plasmid pEGFP-N1, pEGFP-N1-NPM-ALK and pEGFP-N1-NPM-ALK(644, 664); soft agar assay for colony formation was performed to examine the different carcinogenicity of stable cell lines; cell viability of stable cell lines was examined by CCK-8 after the treatment with PPP.</p><p><b>RESULTS</b>The S arrest occurred in both NPM-ALK(644,664) transfected 293T and Jurkat cells; the susceptibility of NPM-ALK transfected Jurkat cells to PPP was highest among the 3 stable cell lines; the phosphorylated levels of AKT, ERK and STAT3 were decreased in NPM-ALK(644,664) cells compared with the NPM-ALK ones. Additionally, the double mutation induced the increase of CDK2 and the decrease of P27 (P<0.05).</p><p><b>CONCLUSION</b>The mutation of Tyr644 and 664 sites in NPM-ALK can induce cell cycle arrest in S phase and lower susceptibility to PPP that may be related with the phosphorylation change of cell growth related molecules in the downstream of NPM-ALK.</p>

Comparative study on changes of digestive and absorptive functions in three different models of Pi-deficiency syndrome / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To compare the changes of digestive and absorptive functions in three different models of Pi-deficiency syndrome (PDS).</p><p><b>METHODS</b>Experimental mice were divided into four groups, the control group(CG), the rhubarb group (RG), the exhaustion group (EG) and the over-exertion group(OG). Criteria including general physical signs, D-xylose excretion rate, serum amylase activity, velocity of stomach emptying and enterokinesia, serum gastrin content and indexes of organs were determined before and after treatment.</p><p><b>RESULTS</b>Decrease of D-xylose excretion rate and increase of stomach emptying and enterokinesia velocity appeared in all the three PDS models. As compared with CG, changes of all indices in OG were significant, while the decreasing of spleen index and serum amylase activity in EG, and the changes of serum gastrin content and thymus index in RG were insignificantly different.</p><p><b>CONCLUSION</b>All the changes in various criteria showed that PDS mice model established by over-exertion was superior to that established by frequently used methods as purging with rhubarb and exhausting by swimming.</p>