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- Bäckman, Eva, 1968-, et al.
(författare)
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Thioredoxin, produced by stromal cells retrieved from the lymph node microenvironment, rescues chronic lymphocytic leukemia cells from apoptosis in vitro
- 2007
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Ingår i: Haematologia. - : Ferrata Storti Foundation (Haematologica). - 0017-6559 .- 1568-5594 .- 0390-6078 .- 1592-8721. ; 92:11, s. 1495-1504
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Tidskriftsartikel (refereegranskat)abstract
- Background and Objectives: The redox-regulatory protein thioredoxin has several functions including transcriptional regulation, and antioxidant, cytokine, and chemokine activities. We have previously shown that extracellular thioredoxin protects B-cell chronic lymphocytic leukemia (CLL) cells from apoptosis in vitro. In this study we were interested to determine whether thioredoxin is produced by cells surrounding the CLL cells in the in vivo microenvironment and whether this cell-derived thioredoxin has any leukemia growth-promoting effect in vitro. Design and Methods: Lymph nodes from CLL patients (n=25) were analyzed for thioredoxin expression by immunohistology. Stromal cells purified from the lymph nodes were analyzed for thioredoxin secretion at the single cell level using an ELIspot assay. The survival effect of the stromal-derived thioredoxin was tested by co-culturing stromal- and CLL cells with and without Fab-fragments of an anti-thioredoxin antibody. Results: The results indicated that the thioredoxin production correlated with the amount of proliferating cells and was mainly localized to the proliferation centers (pseudofollicles) in the CLL lymph nodes. The leukemia cells per se showed minimal thioredoxin levels; in contrast, stromal cells strongly expressed thioredoxin. Purified primary stromal cells, which secreted extracellular thioredoxin, significantly protected the CLL cells from undergoing apoptosis in 72 h co-cultures. Interestingly, this anti-apoptotic effect could be abrogated by addition of Fab-fragments of an anti- thioredoxin antibody. Interpretation and Conclusions: In conclusion, we have shown that stromal cells in the lymph node microenvironment produce thioredoxin and that the thioredoxin production is localized to the proliferation centers of the CLL lymph nodes. In addition, thioredoxin produced by purified stromal cells rescued CLL cells from apoptosis in vitro.
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- Grabowski, Pawel, 1975-, et al.
(författare)
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Telomere length as a prognostic parameter in chronic lymphocytic leukemia with special reference to VH gene mutation status
- 2005
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 105:12, s. 4807-4812
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Tidskriftsartikel (refereegranskat)abstract
- B-cell chronic lymphocytic leukemia (CLL) consists of 2 prognostic entities where cases with mutated immunoglobulin VH genes have better outcome than unmutated cases. VH-mutated CLLs display longer telomeres compared with unmutated cases and telomere length has been indicated to predict outcome, although the prognostic value of telomere length has not been fully established in CLL. We analyzed telomere length, VH gene mutation status, and clinical parameters in a large series of CLL. Telomere length was assessed by quantitative polymerase chain reaction (PCR), giving a very good correlation to telomere length estimated by Southern blotting (P < .001). The prognostic information given by mutation status (n = 282) and telomere length (n = 246) was significant (P < .001, respectively). Telomere length was a prognostic factor for stage A (P = .021) and stage B/C (P = .018) patients, whereas mutation status predicted outcome only in stage A patients (P < .001). Furthermore, mutated CLLs were subdivided by telomere length into 2 groups with different prognoses (P = .003), a subdivision not seen for unmutated cases (P = .232). Interestingly, the VH-mutated group with short telomeres had an overall survival close to that of the unmutated cases. Thus, by combining VH mutation status and telomere length, an improved subclassification of CLL was achieved identifying previously unrecognized patient groups with different outcomes.
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- Kanduri, Meena, et al.
(författare)
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The novel NF-kappa B inhibitor IMD-0354 induces apoptosis in chronic lymphocytic leukemia
- 2011
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Ingår i: Blood Cancer Journal. - : Springer Science and Business Media LLC. - 2044-5385. ; 1, s. e12-
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Tidskriftsartikel (refereegranskat)abstract
- Nuclear factor-kappa B (NF-kappa B) is an important regulator of cell survival and has been shown to be constitutively active in chronic lymphocytic leukemia (CLL) cells. Recently, a novel NF-kappa B inhibitor, IMD-0354 (N-(3, 5-bis-trifluoromethyl-phenyl)-5-chloro-2-hydroxy-benzamide), was shown to specifically inhibit the phosphorylation of I kappa B alpha by IkB kinases, thus preventing NF-kappa B release. In this study, we investigated if IMD-0354 can inhibit NF-kappa B activation and induce apoptosis in CLL cells in vitro. The rate of increase in apoptosis, drug sensitivity and DNA-binding activity of NF-kappa B were studied using Annexin V stainings, the fluorometric microculture cytotoxicity assay and electrophoretic mobility shift assay, respectively. Finally, the impact of IMD-0354 treatment on the expression of a set of apoptosis-related genes was investigated. The results clearly show that IMD-0354 induced apoptosis (mean 26%, range 8-48%) in CLL cells, independent of immunoglobulin heavy variable (IGHV) gene mutational status, and showed a dose-dependent cytotoxic effect. IMD-0354 treatment also significantly lowered the DNA-binding activity of NF-kappa B in CLL cells. In addition, we identified differences in expression levels of pro- and antiapoptotic genes following IMD-0354 treatment. In summary, our novel findings show that IMD-0354 can induce apoptosis in CLL cells, and thus merits further investigation as an anticancer agent in vivo.
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- Lanemo Myhrinder, Anna, 1975-, et al.
(författare)
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A new perspective : molecular motifs on oxidized LDL, apoptotic cells, and bacteria are targets for chronic lymphocytic leukemia antibodies
- 2008
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 111:7, s. 3838-3848
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Tidskriftsartikel (refereegranskat)abstract
- The restricted immunoglobulin (Ig) repertoire found in B-cell chronic lymphocytic leukemia (CLL) implies a role for antigen(s) in the leukemogenesis. The nature of the antigens has, however, not been characterized, although examples of autoantigens have been demonstrated. We have analyzed a panel of 28 CLL cell lines and primary cultures, producing monoclonal Ig with different Ig heavy-chain variable region gene usage and mutational status, including several complementarity determining region 3 homology subset members. Using mass-spectrometry, immunoassays, or protein macroarrays, we have discovered novel antigens binding to CLL Igs. These antigens included cytoskeletal proteins vimentin, filamin B, and cofilin-1, but also phosphorylcholine-containing antigens (eg, Streptococcus pneumoniae polysaccharides and oxidized low-density lipoprotein [oxLDL]). Additional new antigens identified were cardiolipin and proline-rich acidic protein-1. Remarkably, these antigens represent molecular motifs exposed on apoptotic cells/blebs and bacteria, and several CLL Igs bound to apoptotic Jurkat cells. In conclusion, these intriguing data, showing a limited target structure recognition, indicate that CD5(+) CLL B cells are derived from a cell compartment that produces "natural antibodies," which may be instrumental in elimination and scavenging of apoptotic cells and pathogenic bacteria.
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- Lindhagen, Elin, et al.
(författare)
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In vitro activity of 20 agents in different prognostic subgroups of chronic lymphocytic leukaemia : rolipram and prednisolone active in cells from patients with poor prognosis
- 2009
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Ingår i: European Journal of Haematology. - : Wiley. - 0902-4441 .- 1600-0609. ; 83:1, s. 22-34
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Tidskriftsartikel (refereegranskat)abstract
- Background: There is a need for development of new drugs for treatment of B-cell chronic lymphocytic leukemia (CLL), especially for poor-prognostic subgroups resistant to conventional therapy. Objective: The in vitro antileukaemic activity of 20 different anticancer agents was characterized in tumour cells from CLL, aiming at identifying agents active in poor-prognostic subgroups.Design and methods: In tumour cells from 40 CLL patients and in peripheral blood mononuclear cells (PBMC) from 3 healthy controls, the activity of 20 substances was assessed using a non-clonogenic assay. The CLL samples were characterized regarding genomic aberrations by interphase FISH and immunoglobulin heavy-chain variable (IGHV) gene mutational status.Results:In line with clinical experience, cells from patients with unfavourable genomic aberrations (del(11q)/del(17p)) showed lower drug sensitivity to fludarabine and chlorambucil than cells from patients with favourable cytogenetics (del(13q)/no aberration). Most investigated drugs demonstrated similar activity in CLL cells from patients with unmutated and mutated IGHV genes as well as in CLL cells versus PBMC. Interestingly, prednisolone and rolipram displayed high CLL specificity, high activity in CLL cells with unmutated IGHV genes and retained the effect in several cases with 11q/17p deletion. Further studies on prednisolone and rolipram revealed a synergy when these agents were combined in CLL cells, and suggested correlation between drug sensitivity and difference in downstream signalling.Conclusion:Prednisolone and rolipram are interesting for further studies in CLL with inferior prognosis. The study can also be considered a basis for future efforts to find drugs active in subsets of CLL patients that are resistant to conventional therapy.
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- Mansouri, Mahmoud, et al.
(författare)
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Lipoprotein lipase is differentially expressed in prognostic subsets of chronic lymphocytic leukemia but displays invariably low catalytical activity
- 2010
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Ingår i: Leukemia Research. - : Elsevier BV. - 0145-2126 .- 1873-5835. ; 34:3, s. 301-306
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Tidskriftsartikel (refereegranskat)abstract
- Lipoprotein lipase (LPL) expression has been shown to correlate with IGHV mutational status and to predict outcome in chronic lymphocytic leukemia (CLL). We here investigated the prognostic impact of LPL expression in relation to other prognostic markers including IGHV3-21 usage in 140 CLL patients. Additionally, we studied the catalytic activity of LPL in CLL cells. A significant difference in LPL mRNA expression was detected in IGHV unmutated compared to mutated CLL patients (p<0.001). However, the poor-prognostic mutated/stereotyped IGHV3-21 patients did not differ from other mutated CLL cases. Clinical outcome was significantly different in CLL cases with high versus low LPL expression (p<0.001), and LPL expression exceeded mutation status/IGHV3-21 usage as an independent prognostic marker. Finally, LPL protein expression correlated significantly with mRNA expression and was higher in IGHV unmutated versus mutated CLL (p=0.018), although the majority of synthesized protein was catalytically inactive indicating a non-catalytical function in CLL.
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