Apoptosis of t(14;18)-positive lymphoma cells by a Bcl-2 interacting small molecule.

Overexpression of Bcl-2 protein occurs via both t(14;18)-dependent and independent mechanisms and contributes to the survival and chemoresistance of non-Hodgkin lymphomas. HA14-1 is a nonpeptidic organic small molecule, which has been shown to inhibit the interaction of Bcl-2 with Bax, thereby interfering with the antiapoptotic function of Bcl-2. In this study, we sought to determine the in vitro efficacy of HA14-1 as a therapeutic agent for non-Hodgkin lymphomas expressing Bcl-2.

P38 mitogen activated protein kinase expression and regulation by interleukin-4 in human B cell non-Hodgkin lymphomas.

Unlabelled: The prevalence and regulation of p38 mitogen activated protein kinase (MAPK) expression in human lymphomas have not been extensively studied. In order to elucidate the role of p38 MAPK in lymphomagenesis, we examined the expression of native and phosphorylated p38 (p-p38) MAPK in cell lines derived from human hematopoietic neoplasms including B cell lymphoma-derived cell lines using Western blot analysis. The p-p38 MAPK protein was also analyzed in 30 B cell non-Hodgkin lymphoma (NHL) tissue biopsies by immunohistochemistry.

Proteomic identification of oncogenic chromosomal translocation partners encoding chimeric anaplastic lymphoma kinase fusion proteins.

The anaplastic lymphoma kinase (ALK) on 2p23 is a tyrosine kinase that forms chimeric fusions with numerous translocation partners. We describe a mass spectrometry-based approach for the identification of ALK fusion partners. This approach accurately identified the nucleophosmin (NPM)-ALK fusion protein in an anaplastic large cell lymphoma (ALCL)-derived cell line carrying the t(2;5)(p23;q35), and the TPM3-ALK in a clinical biopsy of inflammatory myofibroblastic tumor (IMT) carrying the t(1;2)(q21;p23).

Expression of the Rho-family GTPase gene RHOF in lymphocyte subsets and malignant lymphomas.

We have studied the expression of RHOF, a member of the Rho-GTPase family, in an array of lymphoid cells and tissues. Previous microarray studies demonstrated RHOF upregulation in a subset of transformed follicular lymphomas. Real-time quantitative polymerase chain reaction evaluated RHOF expression in lymphocyte subpopulations, and normal and malignant lymphoid tissue.

Quantitative proteomic and transcriptional analysis of the response to the p38 mitogen-activated protein kinase inhibitor SB203580 in transformed follicular lymphoma cells.

The p38 mitogen-activated protein kinase (MAPK) is a key mediator of stress, extracellular-, growth factor-, and cytokine-induced signaling, and has been implicated in the development of cancer. Our previous work showed evidence for p38 MAPK activation in a subset of transformed follicular lymphomas (Elenitoba-Johnson et al. (2003) Proc.

Application of SELDI-TOF mass spectrometry for the identification of differentially expressed proteins in transformed follicular lymphoma.

Completion of the human genome project has focused scientific attention on the development of methods that permit rapid characterization of proteins that are encoded by the genome. Recent improvements in two-dimensional separation techniques in combination with protein identification software/databases and mass spectrometry (MS) now permit rapid comprehensive large-scale analysis of individual proteins within complex protein mixtures. We have performed pairwise comparisons of low-grade and transformed follicular lymphomas (FLs) in order to identify proteins that may be involved in FL progression using surface-enhanced laser desorption/ionization time-of-flight (SELDI-TOF) mass spectrometer (ProteinChip, Ciphergen Biosystems).

Utility of linearly amplified RNA for RT-PCR detection of chromosomal translocations: validation using the t(2;5)(p23;q35) NPM-ALK chromosomal translocation.

The requirement for sufficient quantities of starting RNA has limited the ability to evaluate multiple transcripts using reverse transcriptase-polymerase chain reaction (RT-PCR). In this study, we demonstrate the utility of linear RNA amplification for RT-PCR analysis of multiple gene transcripts including a chromosomal translocation, using the t(2;5)(p23;q35) as a model. RNA from the t(2;5)-positive cell line, SU-DHL-1, and the t(2;5)-negative cell line, HUT-78, was extracted and exposed to two rounds of linear amplification.

Involvement of multiple signaling pathways in follicular lymphoma transformation: p38-mitogen-activated protein kinase as a target for therapy.

Follicular lymphoma (FL) is the most common form of low-grade non-Hodgkin's lymphoma. Transformation to diffuse large B cell lymphoma (DLBCL) is an important cause of mortality. Using cDNA microarray analysis we identified 113 transformation-associated genes whose expression differed consistently between serial clonally related samples of FL and DLBCL occurring within the same individual.

Gene expression profiling of cell lines derived from T-cell malignancies.

The expression profiles of eight cell lines derived from T-cell malignancies were compared to CD4-positive T-cells using cDNA microarray technology. Unsupervised hierarchical clustering of 4364 genes demonstrated substantial heterogeneity resulting in four distinct groups. While no genes were found to be uniformly up- or down-regulated across all cell lines, we observed 111 over-expressed genes (greater than two-fold) and 1118 down-regulated genes (greater than two-fold) in the lymphomas as a group when compared to CD4-positive T-cells.

Fluorescence PCR quantification of cyclin D1 expression.

We have used a continuous fluorescence monitoring method to assess cyclin D1 mRNA expression in a variety of hematological and non-hematological processes. We examined 14 cell lines, 11 reactive lymphoid tissues, and 57 primary hematopoietic neoplasms including mantle cell lymphoma (MCL) (n = 10), chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) (n = 11), acute lymphoblastic leukemia/lymphoma (n = 15), follicular lymphoma (n = 6), peripheral T-cell lymphoma (PTCL) (n = 3), anaplastic large cell lymphoma (n = 3), hairy cell leukemia (n = 3), Burkitt lymphoma (n = 1), Burkitt-like lymphoma (n = 4), and plasmacytoma (n = 1) for the expression of cyclin D1 mRNA using fluorescently labeled sequence-specific hybridization probes. Fluorescence (F) was plotted against cycle (C) number over 45 cycles.