SummaryGene expression analysis demonstrated high expression of the neuronal transcription factor SOX11 in mantle cell lymphoma (MCL). In contrast to follicular lymphoma, small lymphocytic lymphoma and reactive lymphoid tissue, most MCLs tested (48/53 patients) expressed sox11 protein in the nucleus. Therefore nuclear sox11 expression represents a new tumour marker for a subset of MCL. However, 5/53 MCL cases expressed sox11 only in the cytoplasm; these MCL patients had a shorter survival compared to MCL with nuclear sox11 expression. These results suggest sox11 expression as a new diagnostic marker in MCL that could be related to the clinical and biological behaviour of MCL.Keywords: mantle cell lymphoma, sox11, nuclear expression, survival, proliferation.short report Materials and methods Tissue and cell linesTumour samples comprised MCL (n = 53), SLL (n = 5) and FL (n = 7) diagnosed at the Department of Pathology, Karolinska University Hospital, Stockholm, Sweden. All diagnoses were established by morphology, immunophenotyping by flow cytometry, immunohistochemistry for cyclin D1 and fluorescence in situ hybridization analysis for the (11;14)(q13;q32). Control tissues were from tonsil tissue (n = 1) and reactive lymph nodes (n = 4). Frozen tissue was stored and handled as described in . Cell linesThe MCL cell lines Rec1, Granta519 and JeKo, the plasma cell leukaemia cell line SK-MM-2, the mouse pituitary cell line AtT20 cell line transfected with cDNA for the rat CB1 receptor and the wild type AtT20 cell line, the acute T-cell leukaemia cell line Jurkat, the precursor T-cell leukaemia cell line MOLT-4 and the breast cancer cell line MCF7 were cultured as previously described (Islam et al, 2003;Flygare et al, 2005;Gustafsson et al, 2006). Gene expression analysisLymph node (n = 10), spleen (n = 3), tonsil (n = 2) and a biopsy from tongue base (n = 1) from 16 patients with MCL were investigated and compared to reactive lymph nodes (n = 6). The methodology and part of this data has been previously published . The data was analysed using Affymetrix Micro array Suite version 5AE0 (Affymetrix, Inc., Santa Clara, CA, USA). Each of the MCL was compared to each of the reactive lymphoid samples. Comparative analyses were carried out on the expression data using Affymetrix Datamining Tool version 3AE0.cDNA synthesis and reverse transcription polymerase chain reaction (RT-PCR) for SOX11Two micrograms of total RNA from primary MCL, FL, reactive lymph nodes, cell lines, mouse 7-d embryo (BD Biosciences Clontech, Palo Alto, CA, USA) and human fetal brain (BD Biosciences) was used for cDNA synthesis using First-strand cDNA synthesis kit (Amersham Biosciences AB, Uppsala, Sweden) according to the manufacturer's protocol. The primers used for RT-PCR were according to Lee et al (2002). For SOX11, 2 ll cDNA was amplified in a volume of 20 ll containing 0AE5 lmol/l of each primer, 100 lmol/l of each dNTP, 15 mmol/l Tris-HCl (pH 8AE0), 50 mmol/l KCl, 1AE5 mmol/l MgCl 2 and 1 Unit Taq Gold Polymerase (Applied Biosystems, Foster Ci...

We have recently shown that cannabinoids induce growth inhibition and apoptosis in mantle cell lymphoma (MCL), a malignant B-cell lymphoma that expresses high levels of cannabinoid receptor types 1 and 2 (CB 1 and CB 2 ). In the current study, the role of each receptor and the signal transduction triggered by receptor ligation were investigated. Induction of apoptosis after treatment with the synthetic agonists R(ϩ)-was dependent on both cannabinoid receptors, because pretreatment with, specific antagonists to CB 1 and CB 2 , respectively, abrogated caspase-3 activity. Preincubation with the inhibitors 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole (SB203580) and 4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)-1H-imidazole (SB202190) showed that phosphorylation of MAPK p38 was implicated in the signal transduction leading to apoptosis. Treatment with R(ϩ)-MA and Win55 was associated with accumulation of ceramide, and pharmacological inhibition of ceramide synthesis de novo prevented both p38 activation and mitochondria depolarization assessed by binding of 3,3Ј-dihexyloxacarbocyanine iodide (DiOC 6 ). In contrast, the pancaspase inhibitor z-Val-Ala-Asp(Ome)-CH 2 F (z-VAD-FMK) did not protect the mitochondrial integrity. Taken together, these results suggest that concurrent ligation of CB 1 and CB 2 with either R(ϩ)-MA or Win55 induces apoptosis via a sequence of events in MCL cells: accumulation of ceramide, phosphorylation of p38, depolarization of the mitochondrial membrane, and caspase activation. Although induction of apoptosis was observed in both MCL cell lines and primary MCL, normal B cells remained unaffected. The present data suggest that targeting CB 1 / CB 2 may have therapeutic potential for the treatment of mantle cell lymphoma.

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