| 81. |
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| 82. |
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| 83. |
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| 84. |
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| 85. |
- Godina, Christopher, et al.
(författare)
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Prognostic impact of tumor-specific insulin-like growth factor binding protein 7 (IGFBP7) levels in breast cancer : A prospective cohort study
- 2021
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Ingår i: Carcinogenesis. - : Oxford University Press (OUP). - 0143-3334 .- 1460-2180. ; 42:11, s. 1314-1325
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Tidskriftsartikel (refereegranskat)abstract
- The prognostic impact of insulin-like growth factor binding protein 7 (IGFBP7) in breast cancer is unclear. Host factors, including lifestyle, anthropometry and metabolic profile, might influence tumor-specific IGFBP7. This study aimed to investigate whether IGFBP7 levels and messenger ribonucleic acid (mRNA) expression are associated with the patient and tumor characteristics and prognosis in breast cancer. Patients with primary breast cancer in Lund, Sweden, were included preoperatively in the study between 2002 and 2012 (n = 1018). Tumor-specific IGFBP7 protein levels were evaluated with immunohistochemistry using tissue microarrays in tumors from 878 patients. IGFBP7 mRNA expression and its corresponding clinical data were obtained from The Cancer Genome Atlas and analyzed for 809 patients. Tumor-specific IGFBP7 protein levels were categorized based on Histo 300 scores into IGFBP7low (6.2%), IGFBP7intermediate (75.7%) and IGFBP7high (18.1%). Both low IGFBP7 protein levels and mRNA expression were associated with less aggressive tumor characteristics. Overall, IGFBP7low conferred low recurrence risk. The prognostic impact of IGFBP7high varied according to any alcohol consumption and tamoxifen treatment. IGFBP7high was associated with low recurrence risk in alcohol consumers but high recurrence risk in alcohol abstainers (Pinteraction= 0.039). Moreover, the combination of IGFBP7high and estrogen receptor-positive tumors was associated with low recurrence risk only in tamoxifen-treated patients (Pinteraction= 0.029). To conclude, IGFBP7low might be a good, independent prognosticator in breast cancer. The prognostic impact of IGFBP7high depends on host factors and treatment. IGFBP7 merits further investigation to confirm whether it could be a suitable biomarker for treatment selection.
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| 86. |
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| 87. |
- Goulet, Anne-Christine, et al.
(författare)
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Selenomethionine induces sustained ERK phosphorylation leading to cell-cycle arrest in human colon cancer cells
- 2005
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Ingår i: Carcinogenesis. - : Oxford University Press (OUP). - 0143-3334 .- 1460-2180. ; 26:1, s. 109-117
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Tidskriftsartikel (refereegranskat)abstract
- Selenomethionine (SeMet) is being tested alone and in combination with other agents in cancer chemoprevention trials. However, the molecular targets and the signaling mechanism underlying the anticancer effect of this compound are not completely clear. Here, we provide evidence that SeMet can induce cell-growth arrest and that the growth inhibition is associated with S-G2/M cell-cycle arrest. Coincidentally with the cell-cycle arrest, we observed a striking increase in cyclin B as well as phosphorylation of the cyclin-dependent kinase Cdc2. Since activation of the mitogen-activated protein kinase (MAPK) cascade has been associated with cell-cycle arrest and growth inhibition, we evaluated the activation of extracellular signal-regulated kinase (ERK). We found that SeMet induced phosphorylation of the MAPK ERK in a dose-dependent manner. We also demonstrate phosphorylation of ribosomal S6 kinase (p90RSK) by SeMet. Additionally, we show phosphorylation of histone H3 in a concentration-dependent manner. Furthermore, the phosphorylation of p90RSK and histone H3 were both antagonized by the MEK inhibitor U0126, implying that SeMet-induced phosphorylation of p90RSK and histone H3 are at least in part ERK pathway dependent. Based on these results, we propose that SeMet induced growth arrest and phosphorylation of histone H3 are mediated by persistent ERK and p90RSK activation. These new data provide valuable insights into the biological effects of SeMet at clinically relevant concentrations.
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| 88. |
- Hakkola, Jukka, et al.
(författare)
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Expression of CYP1B1 in human adult and fetal tissues and differential inducibility of CYP1B1 and CYP1A1 by Ah-receptor ligands in human placenta and cultured cells
- 1997
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Ingår i: Carcinogenesis. - 0143-3334 .- 1460-2180. ; 18:2, s. 391-7
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Tidskriftsartikel (refereegranskat)abstract
- Expression of the Ah receptor-regulated cytochrome P4501B1 (CYP1B1) gene was studied in human adult and fetal tissues and cells in culture by reverse transcriptase-coupled polymerase chain reaction (RT-PCR). In adults, CYP1B1 mRNA was detected in liver, lymphocytes, cells of bronchoalveolar lavage samples and uterine endometrium, but not in lung. The level of expression was very low in adult liver and only three out of six fetal livers expressed CYP1B1. Extrahepatic fetal tissues, especially brains and kidneys, expressed high levels of CYP1B1. CYP1B1 mRNA was constitutively detected at a low level in first trimester and full-term placental samples. A competitive RT-PCR assay was developed to assess the regulation of CYP1B1. CYP1B1 mRNA was not induced in placenta by maternal cigarette smoking. Inducibility of CYP1B1 in cells in culture by the Ah receptor ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin was studied in primary fibroblasts and chorion carcinoma cell line JEG-3 having different CYP1A1 induction properties. Inducibility of CYP1B1 was found to be regulated independently from CYP1A1. In JEG-3 cells CYP1A1 mRNA was induced up to 9000-fold, while the expression of CYP1B1 was not affected. Expression of Ah receptor and Ah receptor nuclear translocator (regulators of the CYP1 family) was determined in human placenta and in the JEG-3 cell line. Expression of these transcription factors was found neither to be co-regulated nor affected by Ah receptor ligands. This study provides evidence that in addition to the Ah receptor complex, other cell-specific factors modulate the response of CYP1B1 and CYP1A1 to Ah receptor ligands.
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| 89. |
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| 90. |
- Haug, Bjørn Helge, et al.
(författare)
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MYCN-regulated miRNA-92 inhibits secretion of the tumor suppressor DICKKOPF-3 (DKK3) in neuroblastoma.
- 2011
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Ingår i: Carcinogenesis. - : Oxford University Press (OUP). - 1460-2180 .- 0143-3334. ; 32:7, s. 1005-12
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Tidskriftsartikel (refereegranskat)abstract
- The MYCN oncogene is frequently amplified in neuroblastoma. It is one of the most consistent markers of bad prognosis for this disease. Dickkopf-3 (DKK3) is a secreted protein of the DKK family of Wnt regulators. It functions as a tumor suppressor in a range of cancers, including neuroblastoma. MYCN was recently found to downregulate DKK3 mRNA. In this study, we show that MYCN knockdown in MYCN-amplified (MNA) neuroblastoma cell lines increases secretion of endogenous DKK3 to the culture media. MicroRNAs (miRNAs) are ∼20 nt long single-stranded RNA molecules that downregulate messenger RNAs by targeting the 3' untranslated region (3'UTR). Many miRNAs regulate genes involved in the pathogenesis of cancer and are extensively deregulated in different tumors. Using miRNA target prediction software, we found several MYCN-regulated miRNAs that could target the 3'UTR sequence of DKK3, including mir-92a, mir-92b and let-7e. Luciferase expression from a reporter vector containing the DKK3-3'UTR was decreased when this construct was cotransfected with mir-92a, mir-92b or let-7e in HEK293 cells. Mutation of the mir-92 seed sequence in the 3'UTR completely rescued the observed decrease in reporter expression when cotransfected with mir-92a and mir-92b. Antagomir and miRNA-mimic transfections in neuroblastoma cell lines confirmed that DKK3 secretion to the culture media is regulated by mir-92. Consistent with reports from other cancers, we found DKK3 to be expressed in the endothelium of primary neuroblastoma samples and to be absent in tumors with MYCN amplification. Our data demonstrate that MYCN-regulated miRNAs are able to modulate the expression of the tumor suppressor DKK3 in neuroblastoma.
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