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- Fridberg, Marie, et al.
(författare)
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Immunohistochemical analyses of phosphatases in childhood B-cell lymphoma : lower expression of PTEN and HePTP and higher number of positive cells for nuclear SHP2 in B-cell lymphoma cases compared to controls
- 2008
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Ingår i: Pediatric Hematology & Oncology. - : Taylor & Francis. - 0888-0018 .- 1521-0669. ; 25, s. 528-540
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Tidskriftsartikel (refereegranskat)abstract
- Although many pediatric B-cell lymphoma patients are being cured today, much is still unknown about the pathogenesis of this disease. Protein tyrosine phosphatases are involved in the control of survival, growth, and differentiation of cells. The authors have analyzed 26 pediatric B-cell lymphoma cases for the expression of a panel of phosphatases and report a statistically significant lower expression intensity of PTEN and HePTP and higher nuclear SHP2 expression in B-cell lymphoma cases compared to lymphoid tissue. Knowledge about the expression of key regulatory proteins in pediatric B-cell lymphomas is necessary for revealing the complex molecular background of this disease.
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| 2. |
- 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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| 3. |
- Stanezai, Sanga, et al.
(författare)
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Higher intensity of low molecular weight protein tyrosine phosphatase/ ACP-1 in survivors of patients diagnosed with diffuse large B cell lymphoma (DLBCL) compared to non-survivors
- 2016
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Ingår i: Austin Biology. - : Austin Publishing. ; 1:2:2
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Tidskriftsartikel (refereegranskat)abstract
- Adult diffuse large B cell lymphoma (DLBCL) is a heterogeneous form of hematopoietic cancer and difficult to treat. In order to find a better diagnostic indication for the disease, we analyzed low molecular weight protein tyrosine phosphatase (LMWPTP) that in humans is encoded by the ACP1 gene. LMWPTP is an enzyme shown to counteract protein tyrosine kinases (PTK) and was suggested to be a negative growth factor regulator. However, the 18 kDa PTP can also have a positive effect on cell growth and proliferation, indicating a controversial role in the tumorigenic process. LMWPTP exists in different isoforms which are electrophoretically, kinetically and immunologically distinct. We have studied two subgroups of DLBCL consisting of a germinal center B cell like (GCB) and a non-germinal center B cell like (non-GCB) group. The two subgroups have been defined by gene-expressing profiling and are associated with differential outcome. The expression levels of LMWPTP protein was compared and showed significant differences between the GCB and non-GCB subgroups (p=0.012). Interestingly, when the samples were divided into survivors and non-survivors, and thereafter analyzed for LMWPTP expression, the samples from patients with a higher survival rate showed increased staining intensity, whereas the samples from patients with lower intensity of LMWPTP did not survive the disease (p=0.001). In conclusion, we have shown that DLBCL patients with worse outcome express LMWPTP with a lower intensity, suggesting a tumor suppressor role for this form of the enzyme.
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