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Guilty bystanders: nurse-like cells as a model of microenvironmental support for leukemic lymphocytes.

Filip AA, Ciseł B, Wąsik-Szczepanek E - Clin. Exp. Med. (2013)

Bottom Line: Nurse-like cells (NLCs) largely contribute to CLL microenvironmental support.The presence of NLCs significantly reduced apoptosis induced with DEX and CLB (p < 0.001; p = 0.012, respectively), and their protective effect was more evident than the effect of recombinant SDF1.Simultaneous aiming at the disruption of several different signaling pathways and/or anti-apoptotic proteins may further improve treatment efficiency.

View Article: PubMed Central - PubMed

Affiliation: Department of Cancer Genetics, Medical University of Lublin, Radziwillowska 11, 20-080, Lublin, Poland, aafilip@hotmail.com.

ABSTRACT
B-cell chronic lymphocytic leukemia (B-CLL) is one of the most common leukemias among the elderly and, despite many efforts, still stays incurable. Recent studies point to the microenvironment as the critical factor providing leukemic lymphocytes with pro-survival signals. Thus, the neighboring cells appear to be a perfect target for antileukemic therapy. Nurse-like cells (NLCs) largely contribute to CLL microenvironmental support. We developed the CLL lymphocyte/NLC co-culture model for the investigation of microenvironmental interactions. Viability and apoptosis were investigated in CLL lymphocytes treated with dexamethasone (DEX) and chlorambucil (CLB), with and without NLCs' support. For the first time, the capacity of DEX and CLB to affect NLCs viability was also evaluated. Apoptosis-associated gene expression profiles of leukemic lymphocytes ex vivo and cultured with NLCs were assessed by expression arrays. CLL lymphocytes escaped spontaneous apoptosis for several months when cultured with NLCs. The presence of NLCs significantly reduced apoptosis induced with DEX and CLB (p < 0.001; p = 0.012, respectively), and their protective effect was more evident than the effect of recombinant SDF1. Both DEX and CLB also decreased NLCs viability, but to a lesser extent (mean viability in DEX-treated cultures was 37.79% in NLCs compared to 29.24% in lymphocytes). NLCs induced the expression of important anti-apoptotic genes in cultured CLL lymphocytes; median expression of BCL2, SURVIVIN, BCL2A1, and XIAP was significantly higher as compared to ex vivo status. The CLL lymphocyte/NLC co-culture makes up the convenient and close to the natural-state model for studying the relationship between leukemic cells and the microenvironment. Direct cell-to-cell contact with NLCs increases the expression of anti-apoptotic genes in CLL lymphocytes, thus protecting them against induced apoptosis. As the effect of antileukemic drugs is not so apparent in NLCs, the combined therapy targeted at both lymphocytes and the microenvironment should be considered for CLL patients. Simultaneous aiming at the disruption of several different signaling pathways and/or anti-apoptotic proteins may further improve treatment efficiency.

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Exemplary CLL lymphocytes viability assessed by FDA in DEX-treated cultures—different variants of culture (patient # 6). FDA—fluorescein diacetate assay, L—untreated CLL lymphocytes (control), L + DEX—CLL lymphocytes treated with dexamethasone for 24 h, L/NLC—CLL lymphocyte/NLC co-culture, L/NLC + DEX—CLL lymphocyte/NLC co-culture treated with DEX for 24 h, L/SDF1—CLL lymphocytes supplemented with SDF1, L/SDF1 + DEX—CLL lymphocytes supplemented with SDF1 treated with DEX for 24 h. (see “Methods” for details). Numbers at the upper right present the proportion of viable cells
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Fig3: Exemplary CLL lymphocytes viability assessed by FDA in DEX-treated cultures—different variants of culture (patient # 6). FDA—fluorescein diacetate assay, L—untreated CLL lymphocytes (control), L + DEX—CLL lymphocytes treated with dexamethasone for 24 h, L/NLC—CLL lymphocyte/NLC co-culture, L/NLC + DEX—CLL lymphocyte/NLC co-culture treated with DEX for 24 h, L/SDF1—CLL lymphocytes supplemented with SDF1, L/SDF1 + DEX—CLL lymphocytes supplemented with SDF1 treated with DEX for 24 h. (see “Methods” for details). Numbers at the upper right present the proportion of viable cells

Mentions: Treatment with either DEX or CLB induced apoptosis in leukemic cells as compared to control cultures (Fig. 3, Supplementary Table S3 and S4). Median lymphocyte viability assessed by FDA was lower in cultures treated with DEX or CLB than in untreated ones (31.81 vs 82.13 %, p < 0.0001 and 45.84 vs 79.34 %, p < 0.0001, respectively).Fig. 3


Guilty bystanders: nurse-like cells as a model of microenvironmental support for leukemic lymphocytes.

Filip AA, Ciseł B, Wąsik-Szczepanek E - Clin. Exp. Med. (2013)

Exemplary CLL lymphocytes viability assessed by FDA in DEX-treated cultures—different variants of culture (patient # 6). FDA—fluorescein diacetate assay, L—untreated CLL lymphocytes (control), L + DEX—CLL lymphocytes treated with dexamethasone for 24 h, L/NLC—CLL lymphocyte/NLC co-culture, L/NLC + DEX—CLL lymphocyte/NLC co-culture treated with DEX for 24 h, L/SDF1—CLL lymphocytes supplemented with SDF1, L/SDF1 + DEX—CLL lymphocytes supplemented with SDF1 treated with DEX for 24 h. (see “Methods” for details). Numbers at the upper right present the proportion of viable cells
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4308641&req=5

Fig3: Exemplary CLL lymphocytes viability assessed by FDA in DEX-treated cultures—different variants of culture (patient # 6). FDA—fluorescein diacetate assay, L—untreated CLL lymphocytes (control), L + DEX—CLL lymphocytes treated with dexamethasone for 24 h, L/NLC—CLL lymphocyte/NLC co-culture, L/NLC + DEX—CLL lymphocyte/NLC co-culture treated with DEX for 24 h, L/SDF1—CLL lymphocytes supplemented with SDF1, L/SDF1 + DEX—CLL lymphocytes supplemented with SDF1 treated with DEX for 24 h. (see “Methods” for details). Numbers at the upper right present the proportion of viable cells
Mentions: Treatment with either DEX or CLB induced apoptosis in leukemic cells as compared to control cultures (Fig. 3, Supplementary Table S3 and S4). Median lymphocyte viability assessed by FDA was lower in cultures treated with DEX or CLB than in untreated ones (31.81 vs 82.13 %, p < 0.0001 and 45.84 vs 79.34 %, p < 0.0001, respectively).Fig. 3

Bottom Line: Nurse-like cells (NLCs) largely contribute to CLL microenvironmental support.The presence of NLCs significantly reduced apoptosis induced with DEX and CLB (p < 0.001; p = 0.012, respectively), and their protective effect was more evident than the effect of recombinant SDF1.Simultaneous aiming at the disruption of several different signaling pathways and/or anti-apoptotic proteins may further improve treatment efficiency.

View Article: PubMed Central - PubMed

Affiliation: Department of Cancer Genetics, Medical University of Lublin, Radziwillowska 11, 20-080, Lublin, Poland, aafilip@hotmail.com.

ABSTRACT
B-cell chronic lymphocytic leukemia (B-CLL) is one of the most common leukemias among the elderly and, despite many efforts, still stays incurable. Recent studies point to the microenvironment as the critical factor providing leukemic lymphocytes with pro-survival signals. Thus, the neighboring cells appear to be a perfect target for antileukemic therapy. Nurse-like cells (NLCs) largely contribute to CLL microenvironmental support. We developed the CLL lymphocyte/NLC co-culture model for the investigation of microenvironmental interactions. Viability and apoptosis were investigated in CLL lymphocytes treated with dexamethasone (DEX) and chlorambucil (CLB), with and without NLCs' support. For the first time, the capacity of DEX and CLB to affect NLCs viability was also evaluated. Apoptosis-associated gene expression profiles of leukemic lymphocytes ex vivo and cultured with NLCs were assessed by expression arrays. CLL lymphocytes escaped spontaneous apoptosis for several months when cultured with NLCs. The presence of NLCs significantly reduced apoptosis induced with DEX and CLB (p < 0.001; p = 0.012, respectively), and their protective effect was more evident than the effect of recombinant SDF1. Both DEX and CLB also decreased NLCs viability, but to a lesser extent (mean viability in DEX-treated cultures was 37.79% in NLCs compared to 29.24% in lymphocytes). NLCs induced the expression of important anti-apoptotic genes in cultured CLL lymphocytes; median expression of BCL2, SURVIVIN, BCL2A1, and XIAP was significantly higher as compared to ex vivo status. The CLL lymphocyte/NLC co-culture makes up the convenient and close to the natural-state model for studying the relationship between leukemic cells and the microenvironment. Direct cell-to-cell contact with NLCs increases the expression of anti-apoptotic genes in CLL lymphocytes, thus protecting them against induced apoptosis. As the effect of antileukemic drugs is not so apparent in NLCs, the combined therapy targeted at both lymphocytes and the microenvironment should be considered for CLL patients. Simultaneous aiming at the disruption of several different signaling pathways and/or anti-apoptotic proteins may further improve treatment efficiency.

Show MeSH
Related in: MedlinePlus