| 1. |
- Bergh, Ann-Charlotte, et al.
(författare)
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B cell receptor signaling suppressor SHP-1 is active in CLL lymph node and peripheral blood
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Protein tyrosine phosphatase SHP-1 expression and activity is downregulated or lost in several leukemias and lymphomas due to DNA promotor hypermethylation, catalytic site mutation or oxidation, or phosphorylation at inhibitory sites, implying a negative role of SHP-1 in development of leukemias/lymphomas. In chronic lymphocytic leukemia (CLL), B cell receptor (BcR) and microenvironment signal levels are important in the pathogenesis. Considering that SHP-1 is a BcR signaling suppressor, we hypothesized that SHP-1 would be down-regulated and/or inactivated in the proliferative center lymph node (LN) cells. We analyzed PTPN6 (SHP-1) gene expression, SHP-1 protein expression and phosphorylation status in matched CD5+/CD19+ peripheral blood (PB) and LN cells from 6 CLL patients, and in comparison, BcR (anti-IgM) in vitro triggered CLL PB cells from 10 patients. Gene expression of PTPN6 was significantly higher in PB compared to LN CLL cells in 50% of the cases. SHP-1 protein expression level and phosphorylation at SHP-1Y536 and SHP-1S591 were, however, equal in PB and LN samples. SHP-1 phosphorylation at Y536 and S591, in PB CLL cells cultured ex vivo was significantly reduced upon BcR engagement in all patient samples. These results indicate that in vivo BcR signaling in CLL is paralyzed.
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| 2. |
- El-Schich, Zahra, et al.
(författare)
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Different expression levels of glycans on leukemic cells-a novel screening method with molecularly imprinted polymers (MIP) targeting sialic acid
- 2016
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Ingår i: Tumor Biology. - : Springer. - 1010-4283 .- 1423-0380. ; 10:37, s. 13763-13768
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Tidskriftsartikel (refereegranskat)abstract
- Sialic acid (SA) is normally expressed on the cell membranes and is located at the terminal position of the sugar chains. SA plays an important role for regulation of the innate immunity, function as markers of the cells and can be recognized by a variety of receptors. Interestingly, the level of SA expression is increased on metastatic cancer cells. The availability of specific antibodies against SA is limited and, therefore, biomarker tools for detection of SA are lacking. We have recently presented a novel method for specific fluorescence labeling of SA molecular imprinted polymers (MIP). Here, we have performed an extended screening of SA expression by using SA-MIP and included four different chronic lymphocytic leukemia (CLL) cell lines, conveniently analyzed by flow cytometry and fluorescence microscopy. SA expression was detected in four cell lines at different levels, and the SA expression were verified with lectin-FITC. These results show that SA-MIP can be used as a plastic antibody for detection of SA using both flow cytometry and fluorescence microscopy. We suggest that SA-MIP can be used for screening of different tumor cells of various stages, including CLL cells.
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| 3. |
- Fridberg, Marie, et al.
(författare)
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Protein expression and cellular localization in two prognostic subgroups of diffuse large B-cell lymphoma : higher expression of ZAP70 and PKC-beta II in the non-germinal center group and poor survival in patients deficient in nuclear PTEN
- 2007
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Ingår i: Leukemia and Lymphoma. - : Informa UK Limited. - 1042-8194 .- 1029-2403. ; 48:11, s. 2221-2232
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Tidskriftsartikel (refereegranskat)abstract
- Patients diagnosed with diffuse large B-cell lymphoma (DLBCL) show varying responses to conventional therapy, and this might be contributed to the differentiation stage of the tumor B-cells. The aim of the current study was to evaluate a panel of kinases (ZAP70, PKC-β I and II and phosphorylated PKB/Akt) and phosphatases (PTEN, SHP1 and SHP2) known to be frequently deregulated in lymphoid malignancies. De novo DLBCL cases were divided into two subgroups, the germinal center (GC) group (14/28) and the non-germinal center (non-GC) or activated B-cell (ABC) group (14/28). ZAP70 and PKC-β II were expressed in a significantly higher percentage of tumor cells in the clinically more aggressive non-GC group compared with the prognostically favourable GC group. Also, the subcellular localization of PKC-β I and II differed in DLBCL cells, with the PKC-β I isoform being expressed in both the cytoplasm and nucleus, while PKC-β II was found exclusively in the cytoplasm. Loss of nuclear PTEN correlated with poor survival in cases from both subgroups. In addition, five cell lines of DLBCL origin were analyzed for protein expression and for mRNA levels of PTEN and SHP1. For the first time, we show that ZAP70 is expressed in a higher percentage of tumor cells in the aggressive non-GC subgroup of DLBCL and that PKC-β I and II are differently distributed in the two prognostic subgroups of de novo DLBCL.
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