Many patients with PTMC had clinical and histopathological poor prognostic factors. The expression of molecular markers, such as EGFR and COX-2, may have a role in the prognosis of PTMC. When considering all of the prognostic factors, a more tailored management approach appears to be necessary for patients with PTMC.
A-T (ataxia telangiectasia) is a genetic disease caused by a mutation in the Atm (A-T mutated) gene that leads to neurodegeneration. Despite an increase in the numbers of studies in this area in recent years, the mechanisms underlying neurodegeneration in human A-T are still poorly understood. Previous studies demonstrated that neural stem cells (NSCs) isolated from the subventricular zone (SVZ) of Atm
-/- mouse brains show defective self-renewal and proliferation, which is accompanied by activation of chronic p38 mitogen-activated protein kinase (MAPK) and a lower level of the polycomb protein Bmi-1. However, the mechanism underlying Bmi-1 down-regulation and its relevance to defective proliferation in Atm-/- NSCs remained unclear. Here, we show that over-expression of Bmi-1 increases self-renewal and proliferation of Atm-/- NSCs to normal, indicating that defective proliferation in Atm-/- NSCs is a consequence of down-regulation of Bmi-1. We also demonstrate that epidermal growth factor (EGF)-induced Akt phosphorylation renders Bmi-1 resistant to the proteasomal degradation, leading to its stabilization and accumulation in the nucleus. However, inhibition of the Akt-dependent Bmi-1 stabilizing process by p38 MAPK signaling reduces the levels of Bmi-1. Treatment of the Atm-/- NSCs with a specific p38 MAPK inhibitor SB203580 extended Bmi-1 posttranscriptional turnover and H2A ubiquitination in Atm-/- NSCs. Our observations demonstrate the molecular basis underlying the impairment of self-renewal and proliferation in Atm-/- NSCs through the p38 MAPK-Akt-Bmi-1-p21 signaling pathway.
Veronica peregrina has a wide range of types of constituents with various pharmacological properties. Here in this study, we isolated protocatechuic acid (PCA) from V. peregrina and examined PCAs effects on the lifespan and stress tolerance using Caenorhabditis elegans model system. We found that lifespan of wild-type worms was significantly lengthened in the presence of PCA in a dose dependent manner. PCA also elevated tolerance of worms against osmotic, heat shock, and oxidative stress. We also demonstrated antioxidant capacity of PCA by checking intracellular reactive oxygen species level and antioxidant enzyme activities such as catalase and superoxide dismutase. We further investigated several factors including pharyngeal pumping rate and progeny production that might influence prolonged lifespan and enhanced stress tolerance by PCA. Interestingly, both factors were significantly reduced after PCA exposure, indicating PCA exerts longevity activity by shifting food intake and reproduction at least in part. In addition, PCA-treated aged worms showed increased body movement compared to untreated controls suggesting PCA could enhance healthspan as well as lifespan.
We describe the effect of recombinant canstatin, the NC1 domain of the a2 chain of Type IV collagen, on suppression of angiogenesis and lymphangiogenesis both in vitro and in vivo. Recombinant canstatin produced from stably transformed Drosophila S2 cells reduced the expression of angiopoietin-1 in hypoxia mimetic agent, CoCl 2 -treated CT-26 cells. Recombinant canstatin inhibited proliferation, tube formation and migration of human angiopoietin-1 (rhAngpt-1)-treated human umbilical vein endothelial cells (HUVEC) and lymphatic endothelial cells (LEC). Recombinant canstatin suppressed the expression of Tie-2 and vascular endothelial growth factor-3 (VEGFR-3) transcripts in rhAngpt-1-treated HUVEC and LEC, respectively. The inhibitory effect of recombinant canstatin on tumor growth was also investigated using a heterotopic CT-26 colon carcinoma animal (BALB/c mice) model. Recombinant canstatin reduced the final volume and weight of tumors, and blood and lymphatic vessel densities of tumors, which were evaluated by CD-31 and LYVE-1 immunostaining. Immunohistochemical analysis showed that recombinant canstatin dramatically reduced the expression of angiopoietin-1 in CT-26 colon carcinoma-induced tumor, but not the expression of VEGF-C. Tie-2 and VEGFR-3 expressions were also reduced in recombinant canstatin-treated tumors. These results indicate that recombinant canstatin has anti-tumoral activities against CT-26 colon carcinoma cells. Recombinant canstatin reduces the expression of angiopoietin-1 in hypoxia-induced CT-26 cells and inhibits the angiogenic and lymphangiogenic signaling induced by angiopoietin-1. Recombinant canstatin probably inhibits angiogenesis and lymphangiogenesis via suppression of the integrin-dependent FAK signaling induced by angiopoietin-1/Tie-2 and/or VEGFR-3.
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