Project description:Among B-cell lymphomas mantle cell lymphoma (MCL) has the worst prognosis. By using a combination of genomic and expression profiling (Affymetrix GeneChip Mapping 10k Xba131 and U133 set), we analysed 26 MCL samples to identify genes relevant to MCL pathogenesis and that could represent new therapeutic targets. Recurrent genomic deletions and gains were detected. Genes were identified as overexpressed in regions of DNA gain on 3q, 6p, 8q, 9q, 16p and 18q, including the cancer genes BCL2 and MYC. Among the transcripts with high correlation between DNA and RNA, we identified SYK, a tyrosine kinase involved in B-cell receptor signalling. SYK was amplified at DNA level, as validated by fluorescence in situ hybridisation (FISH) analysis, and overexpressed at both RNA and protein levels in the JeKo-1 cell line. Low-level amplification, with protein overexpression of Syk was demonstrated by FISH in a small subset of clinical samples. After treatment with low doses of the Syk inhibitor piceatannol, cell proliferation arrest and apoptosis were induced in the cell line overexpressing Syk, while cells expressing low levels of Syk were much less sensitive. A combination of genomic and expression profiling suggested Syk inhibition as a new therapeutic strategy to be explored in lymphomas.
Project description:Among B-cell lymphomas mantle cell lymphoma (MCL) has the worst prognosis. By using a combination of genomic and expression profiling (Affymetrix GeneChip Mapping 10k Xba131 and U133 set), we analysed 26 MCL samples to identify genes relevant to MCL pathogenesis and that could represent new therapeutic targets. Recurrent genomic deletions and gains were detected. Genes were identified as overexpressed in regions of DNA gain on 3q, 6p, 8q, 9q, 16p and 18q, including the cancer genes BCL2 and MYC. Among the transcripts with high correlation between DNA and RNA, we identified SYK, a tyrosine kinase involved in B-cell receptor signalling. SYK was amplified at DNA level, as validated by fluorescence in situ hybridisation (FISH) analysis, and overexpressed at both RNA and protein levels in the JeKo-1 cell line. Low-level amplification, with protein overexpression of Syk was demonstrated by FISH in a small subset of clinical samples. After treatment with low doses of the Syk inhibitor piceatannol, cell proliferation arrest and apoptosis were induced in the cell line overexpressing Syk, while cells expressing low levels of Syk were much less sensitive. A combination of genomic and expression profiling suggested Syk inhibition as a new therapeutic strategy to be explored in lymphomas. Keywords: cell type comparison
Project description:Mantle Cell Lymphoma (MCL) is a mostly incurable malignancy arising from naïve B cells (NBC) in the mantle zone of lymph node follicles. We analyzed genome-wide methylation in MCL patients using the HELP (Hpa II tiny fragment Enrichment by Ligation mediated PCR) assay and found significant aberrancy in promoter methylation patterns as compared to normal NBCs. Using biological and stringent statistical criteria, we further identified four hypermethylated genes CDKN2B, MLF-1, PCDH8, HOXD8 and four hypomethylated genes CD37, HDAC1, NOTCH1 and CDK5 where aberrant methylation was associated with inverse changes in mRNA levels. MassArray Epityper analysis confirmed the presence of differential methylation at the promoter region of these genes. Immunohistochemical analysis of an independent cohort of 14 MCL patient samples, confirmed CD37 surface expression in 93% of patients, validating its selection as a target for MCL therapy. Treatment of MCL cell lines with a novel small modular immunopharmaceutical(CD37-SMIP) resulted in significant loss of viability in cell lines with intense surface CD37 expression. Treatment of MCL cell lines with the DNA methyltransferase inhibitor decitabine resulted in reversal of aberrant hypermethylation and synergized with the HDAC inhibitor SAHA in induction of the four hypermethylated genes CDKN2B, MLF-1, PCDH8 and HOXD8. The combination of Decitabine and SAHA also resulted in potent and synergistic anti-MCL cytotoxicity as compared to either drug alone. In conclusion, our analysis shows prominent and aberrant methylation of the MCL genome and identifies novel differentially methylated and expressed genes in MCL cell lines and patient samples. Furthermore, our data suggest that differentially methylated genes can be targeted for therapeutic benefit in MCL. Gene expression profiling by array comprised of 8 mantle cell lymphoma (MCL) cell lines and 8 leukemic blast from blood from patients newly diagnosed with MCL. Unbiased genome-wide analysis of DNA methylation in leukemic blast from peripheral blood or pheresis products from 22 patients newly diagnosed with mantle cell lymphoma (MCL) prior to any treatment. 10 IgD+ Na ve B cells from specimens from healthy donors undergoing routine tonsillectomy were used as appropriate controls. Methylation patterns of 13 MCL cell lines were also compared.
Project description:Ewing Sarcoma (EWS) is a devastating soft tissue sarcoma affecting predominantly young individuals. Tyrosine kinases (TKs) and associated pathways are continuously activated in many malignancies including EWS; these enzymes provide candidate therapeutic targets. Using two high-throughput screens with EWS cell lines (a siRNA library and a small-molecule inhibitor library of that predominantly target the TK family), we identified spleen tyrosine kinase (SYK) as a candidate actionable target. SYK is highly phosphorylated in the majority of EWS cells, and SYK inhibition by a variety of genetic and pharmacological approaches markedly inhibited EWS cells both in vitro and in vivo. Ectopic expression of SYK rescued the cytotoxicity triggered by SYK-depletion associated with the reactivation of AKT and c-MYC. Transcriptome analysis identified that a Long non-coding RNA, metastasis associated lung adenocarcinoma transcript 1 (MALAT1), was dependent on by SYK-mediated signaling. Moreover, c-MYC, a SYK up-regulated gene, bound to the promoter region of MALAT1 and transcriptional activated MALAT1, which further promoted the proliferation of EWS cells. Taken together, the present study identifies a novel signaling involving SYK/c-MYC/MALAT1 as a promising therapeutic target for the treatment of EWS.
Project description:The existence of clonal heterogeneity of mantle cell lymphoma based on genomic aberration evaluated by log2 ratio(clinical samples)
Project description:The neural transcription factor SOX11 is overexpressed in aggressive lymphoid neoplasms mainly in mantle cell lymphoma (MCL), but its functional role in malignant B-cells is unknown. To identify target genes transcriptionally regulated by SOX11 in malignant lymphoid cells, we have used Gene Expression Profiling (GEP) after SOX11 silencing in MCL cell lines.