| 1. |
- Wang, Mojin, et al.
(författare)
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The PKA RI alpha/A-kinase anchoring proteins 10 signaling pathway and the prognosis of colorectal cancer
- 2015
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Ingår i: Journal of Gastroenterology and Hepatology. - : Wiley: 12 months. - 0815-9319 .- 1440-1746. ; 30:3, s. 496-503
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Tidskriftsartikel (refereegranskat)abstract
- Background and AimPreviously study showed that the loss of the control of cAMP-dependent protein kinase A RI (PKA RI)/ A-kinase anchoring proteins 10 (AKAP10) signaling pathway initiate dysregulation of cellular healthy physiology leading to tumorigenesis. The aim of this study was to investigate the role of PKA RI/AKAP10 signaling pathway in colorectal cancer (CRC). MethodsThe AKAP10 expression at the mRNA and protein level have been analyzed in colon cancer cell lines, primary CRCs and matched normal mucosa samples, and compared in accordance with specific clinicopathological features of CRC. The correlation between expression of AKAP10 and PKA RI were also analyzed. ResultsCompared with HCT116 and SW480 cells, the AKAP10 was significantly upregulated in the colon cell line KM12C and its metastatic counterparts, KM12SM and KM12L4A. Moreover, the KM12SM and KM12L4A having high metastatic potentials displayed the elevated levels of AKAP10 compared with KM12C having poor metastatic potential. A notably higher level of AKAP10 expression was found in CRC tissues at both mRNA and protein levels. Increased expression of AKAP10 in CRC patients was positively associated with the depth of invasion and the grade of differentiation. Univariate survival analysis showed that the increased expression of AKAP10 was related to poorer survival. Cox multivariate regression analysis confirmed that AKAP10 was an independent predictor of the overall survival of CRC patients. PKA RI mRNA was also expressed at high levels in CRC. The correlation coefficient between mRNA expression of AKAP10 and PKA RI in CRC was 0.417. AKAP10mRNA overexpression was correlated significantly with PKA RI. ConclusionsOur data indicated that PKA RI/AKAP10 signaling pathway is associated with the progression and prognosis of CRC.
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| 2. |
- Yang, Lie, et al.
(författare)
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Knockdown of PPAR δ Gene Promotes the Growth of Colon Cancer and Reduces the Sensitivity to Bevacizumab in Nude Mice Model
- 2013
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 8:4
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Tidskriftsartikel (refereegranskat)abstract
- The role of peroxisome proliferator – activated receptor- δ (PPAR δ) gene in colon carcinogenesis remains highly controversial. Here, we established nude mice xenograft model using a human colon cancer cell line KM12C either with PPAR δ silenced or normal. The xenografts in PPAR δ-silenced group grew significantly larger and heavier with less differentiation, promoted cell proliferation, increased expression of vascular endothelial growth factor (VEGF) and similar apoptosis index compared with those of PPAR δ-normal group. After treated with the specific VEGF inhibitor bevacizumab, the capacities of growth and proliferation of xenografts were decreased in both groups while still significantly higher in PPAR δ-silenced group than in PPAR δ-normal group. Administration of PPAR δ agonist significantly decreased VEGF expression in PPAR δ-normal KM12C cells but not in PPAR δ-silenced cells. These findings demonstrate that, knockdown of PPAR δ promotes the growth of colon cancer by inducing less differentiation, accelerating the proliferation and VEGF expression of tumor cells in vivo, and reduces tumor sensitivity to bevacizumab. This study indicates that PPAR δ attenuates colon carcinogenesis.
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| 3. |
- Zhang, Jiao, et al.
(författare)
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Wnt inhibitory factor-1 functions as a tumor suppressor through modulating Wnt/β-catenin signaling in neuroblastoma
- 2014
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Ingår i: Cancer Letters. - : Elsevier. - 0304-3835 .- 1872-7980. ; 348:1–2, s. 12-19
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Tidskriftsartikel (refereegranskat)abstract
- Neuroblastoma is the most common extracranial solid tumor in childhood and is associated with serious morbidity and mortality. The effective treatment of neuroblastoma remains one of the major challenges in pediatric oncology. The Wnt signaling pathway has been shown to play a significant role in the pathogenesis of adult and pediatric tumors. WIF-1 has been identified as an important Wnt antagonist which inhibits Wnt/β-catenin signaling by directly binding to Wnt proteins. However, the expression and function of WIF-1 in neuroblastoma remains unknown. The present study showed that WIF-1 was downregulated with high level promoter methylation in neuroblastoma cells, and was significantly upregulated after exposure to demethylating agent. This finding suggests that downregulation of WIF-1 was associated with its promoter methylation in neuroblastoma. To further study the potential function of WIF-1 in neuroblastoma, we constructed a plasmid that over-expressed WIF-1 and transfected the plasmid into one neuroblastoma cell line SK-N-SH. We found that restoration of WIF-1 inhibited the growth and proliferation of neuroblastoma cells in vitro. Morever, Wnt/β-catenin signaling activity and target genes expression were reduced by WIF-1 restoration. These results provide support that WIF-1 is downregulated and functions as a tumor suppressor by antagonizing Wnt/β-catenin signaling in neuroblastoma, suggesting a potential role as a therapeutic target in neuroblastoma.
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| 4. |
- Zhou, Bin, et al.
(författare)
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PNAS-4 expression and its relationship to p53 in colorectal cancer
- 2012
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Ingår i: Molecular Biology Reports. - : Springer Verlag (Germany). - 0301-4851 .- 1573-4978. ; 39:1, s. 243-249
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Tidskriftsartikel (refereegranskat)abstract
- PNAS-4 is a novel pro-apoptotic protein activated during the early response to DNA damage; however, the molecular mechanisms and pathways regulating PNAS-4 expression in tumors are not well understood. We hypothesized that PNAS-4 is a p53 down-stream target gene and designed this study. We searched online for putative p53-binding sites in the entire PNAS-4 gene and did not find any corresponding information. In HCT116 colon cancer cells, after being transfected with small interfering RNA to silence p53, the expressions of PNAS-4 and other known p53 target gene (Apaf1, Bax, Fas and Dr5) were determined by real-time PCR. We found that PNAS-4 was up-regulated while Apaf1, Bax, Fas and Dr5 were down-regulated. We then examined the expression of PNAS-4 and p53 mutation in colorectal cancer patients. PNAS-4 expressed both in colorectal cancers and normal tissues, but compared with paired control, PNAS-4 was up-regulated in cancers (P = 0.018). PNAS-4 overexpression ratios were correlated to the p53 mutant status (P = 0.001). The mean PNAS-4 expression levels of p53 mutant homozygote group and heterozygote group were higher than that of p53 wild type group (P = 0.013). The expression ratios of PNAS-4 (every sample in relative to its paired normal mucosa) were different between negative lymph node metastasis (66% up-regulated, 34% down-regulated) and positive metastasis (42% up-regulated, 58% down-regulated). Taken together, these findings suggested that PNAS-4 was not a p53 target, but overexpression of PNAS-4 was correlated to p53 inactivity in colorectal cancer.
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| 5. |
- Zhou, Yin, et al.
(författare)
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Inflammation and Apoptosis: Dual Mediator Role for Toll-like Receptor 4 in the Development of Necrotizing Enterocolitis
- 2017
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Ingår i: Inflammatory Bowel Diseases. - : LIPPINCOTT WILLIAMS & WILKINS. - 1078-0998 .- 1536-4844. ; 23:1, s. 44-56
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Tidskriftsartikel (refereegranskat)abstract
- Background: Necrotizing enterocolitis (NEC) is the leading cause of neonatal gastrointestinal mortality; effective interventions are lacking with limited understanding of the pathogenesis of NEC. The importance of Toll-like receptor 4 (TLR4) signaling in NEC is well documented; however, the potential mechanisms that regulate enterocyte inflammation and apoptosis remain unclear. The aim of this study was to characterize the role of TLR4-mediated inflammation and apoptosis in the development of NEC and to determine the major apoptotic pathways and regulators in the process. Methods: TLR4-deficient C57BL/10ScNJ mice and lentivirus-mediated stable TLR4-silent cell line (IEC-6) were used. NEC was induced by formula gavage, cold, hypoxia, combined with lipopolysaccharide in vivo or lipopolysaccharide stimulation in vitro. Enterocyte apoptosis was evaluated by TUNEL or Annexin analysis. The expression of TLR4, caspase3, caspase8, caspase9, Bip, Bax, Bcl-2, and RIP was detected by Western blot and immunofluorescence. Inflammatory factors such as tumor necrosis factor-a and interleukin-2 were examined by Luminex. Results: Defect of TLR4 led to suppressed enterocytes apoptosis both in vitro and in vivo; the expression of caspase3, caspase8, Bip, and Bax was decreased; and caspase9 and Bcl-2 were increased. NEC severity was attenuated in TLR4-deficient mice compared with wild-type counterparts, and enterocytes apoptosis was correlated with NEC severity. RIP and cytokine level of tumor necrosis factor-a and interleukin-2 were also decreased. Conclusions: TLR4-induced inflammation and apoptosis play a critical role in the pathogenesis of NEC. TLR4 inhibition, combined with extrinsic (caspase8) and/or endoplasmic reticulum stress (Bip) apoptosis signaling blockade could serve as a potential effective treating strategy for NEC.
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