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Abstract: Dual specificity phosphatase 6 (DUSP6) is a member of the MAP kinase phophatase family. DUSP6 inactivates extracellular signal-regulated kinase (ERK), belonging to the MAP kinase family, and can act in tumor suppressive pathways. The aim of this study was to investigate associations of DUSP6 expression with expression of ERK and Ki-67 and with clinicopathological parameters in lung adenocarcinoma and squamous cell carcinoma. A total of 102 squamous cell carcinomas and 66 adenocarcinomas were studied using immunohistochemistry for DUSP6, ERK1/2, and Ki-67. In 66 adenocarcinomas, high DUSP6 expression was positively correlated with ERK1/2 expression. High DUSP6 expression was correlated with lower histological grade and lower Ki-67 index in the adenocarcinomas. In 102 squamous cell carcinomas, high DUSP6 expression was correlated with lower ERK expression, with greater smoking pack-years, but not with the Ki-67 index. These results indicate that DUSP6 acts as a negative feedback regulator of ERK in adenocarcinoma progression, but that DUSP6 does not play a role in the downregulation of ERK in squamous cell carcinoma. The differential expression of DUSP6 correlated with Ki-67 index, suggesting that DUSP6 plays an important role in cancer resistance in different subtypes of non-small cell lung carcinoma. [Copyright &y& Elsevier]

Abstract: Mesenchymal stem cells (MSCs) transplantation has been proposed as a promising means for ischemic heart disease. Vascular endothelial growth factor (VEGF) has been demonstrated to play an important role in MSCs transplantation. Angiotensin II (AngII), the most important effector peptide of the renin–angiotensin system (RAS), is also an angiogenesis factor. However, the effects of AngII on VEGF expression in MSCs and the related signaling cascades were unknown. In this experiment, we first demonstrated that incubation of MSCs with AngII-induced a rapid increase in VEGF mRNA expression and protein synthesis. However, these effects were abolished by prior treatment with AngII type 1 (AT1) receptor antagonist losartan while not AngII type 2 (AT2) receptor antagonist PD123319. The addition of either the extracellular signal-regulated kinase 1/2 (ERK1/2) inhibitor U0126 or Akt inhibitor LY294002 also led to a marked inhibition of the AngII-induced VEGF mRNA and protein production. Taken together, these results suggested that AngII stimulated the synthesis of VEGF in MSCs through ERK1/2 and Akt pathway via AT1 receptor. [Copyright &y& Elsevier]