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Lymphoma Subtypes (lymphoma + subtype)

Distribution by Scientific Domains

Medical Sciences	80%

Selected Abstracts

Expression of HYAL2 mRNA, hyaluronan and hyaluronidase in B-cell non-Hodgkin lymphoma: Relationship with tumor aggressiveness

INTERNATIONAL JOURNAL OF CANCER, Issue 2 2005
Philippe Bertrand
Abstract Hyaluronidases and their substrate, hyaluronan (HA), were mainly explored in solid tumors but rarely in hematologic malignancies. While HA involvement was demonstrated in invasion and metastasis in most cases of solid tumors, the role of hyaluronidases in cancer progression remains controversial. One of the hyaluronidases, HYAL2, is suspected to be involved in the first step of HA degradation. In this work, HYAL2 mRNA, HA and total hyaluronidases expression were examined in lymphoma tissue extracts and correlated to the lymphoma subtype. Real-time RT-PCR was performed to evaluate HYAL2 mRNA. HA and hyaluronidase were assayed by enzyme-linked sorbent assay. Our results showed that HYAL2 mRNA expression was correlated to lymphoma diagnosis (p = 6 × 10,3) and was significantly lower in high-grade lymphoma, i.e., diffuse large B-cell diffuse lymphomas (DLBCLs). Several forms of hyaluronidase were detected by zymography and total hyaluronidase activity detected in tissue extracts was not significantly different according to tumor grade. HA levels also correlated to lymphoma subtype (p = 1 × 10,5) and were higher in DLBCLs. Moreover, HYAL2 mRNA and HA expressions were inversely correlated (p = 0.035). HYAL2 gene is localized on chromosome 3p21, which contains candidates tumor suppressor genes. Our results suggest that HYAL2 may have a prognostic significance in lymphomas and an antioncogenic activity. Conversely, HA overexpression in high-grade lymphomas is in favor of its involvement in tumor development and could provide a useful target for lymphoma therapy using HA-binding peptides. [source]

Ophthalmic lymphoma: epidemiology and pathogenesis

ACTA OPHTHALMOLOGICA, Issue thesis1 2009
Lene Dissing Sjö
Abstract With a lifetime risk of 1% and 700 new cases per year, Non-Hodgkin lymphoma (NHL) is the seventh most frequent type of cancer in Denmark. The incidence of NHL has increased considerably in Western countries over the last decades; consequently, NHL is an increasing clinical problem. Ophthalmic lymphoma, (lymphoma localized in the ocular region, i.e. eyelid, conjunctiva, lacrimal sac, lacrimal gland, orbit, or intraocularly) is relatively uncommon, accounting for 5%,10% of all extranodal lymphomas. It is, however, the most common orbital malignancy. The purpose of this thesis was to review specimens from all Danish patients with a diagnosis of ophthalmic lymphoma during the period 1980,2005, in order to determine the distribution of lymphoma subtypes, and the incidence- and time trends in incidence for ophthalmic lymphoma. Furthermore, an extended analysis of the most frequent subtype, extranodal marginal zone lymphoma (MALT lymphoma), was done to analyse clinical factors and cytogenetic changes with influence on prognosis. A total of 228 Danish patients with a biopsy-reviewed verified diagnosis of ocular adnexal-, orbital-, or intraocular lymphoma were identified. We found that more than 50% of orbital- and ocular adnexal lymphomas were of the MALT lymphoma subtype, whereas diffuse large B-cell lymphoma (DLBCL) predominated intraocularly (Sjo et al. 2008a). Furthermore, lymphoma arising in the lacrimal sac was surprisingly predominantly DLBCL (Sjo et al. 2006). Incidence rates were highly dependent on patient age. There was an increase in incidence rates for the whole population from 1980 to 2005, corresponding to an annual average increase of 3.4% (Sjo et al. 2008a). MALT lymphoma arising in the ocular region was found in 116 patients (Sjo et al. 2008b). One third of patients had a relapse or progression of disease after initial therapy and relapses were frequently found at extra-ocular sites. Overall survival, however, was not significantly poorer for patients with relapse. Furthermore, we found that the frequency of translocations involving the MALT1- and IGH-gene loci is low in ocular region MALT lymphoma (2 of 42, 5%), but may predict increased risk of relapse (Sjo et al. 2008b). In conclusion the incidence of ophthalmic lymphoma is increasing at a high rate in Denmark. Ophthalmic lymphoma consists primarily of MALT lymphoma. The molecular pathogenesis of MALT lymphoma arising in the ocular region rarely involves translocations in the MALT1- and IGH-gene loci. [source]

Sample pooling in 2-D gel electrophoresis: A new approach to reduce nonspecific expression background

ELECTROPHORESIS, Issue 22 2006
Marc Weinkauf
Abstract Protein expression alterations unrelated to an investigated phenotype are accumulated in most cell line models during establishment. Performing a whole proteome screening of lymphoma cell lines, we established a method to reduce the influence of protein expression unrelated to the distinct investigated phenotype. In 2-D PAGE, the comprehensive analysis of a large number of protein spots would be simplified by pooling cell line samples of the investigated phenotype. Applying this pooling approach, unrelated alterations of single samples are ,muted' by dilution. Analysing two different lymphoma subtypes (follicular and mantle cell lymphoma) by this method, spots originating in only single cell lines were reduced by 72% (650/900), whereas even modestly altered expression of protein spots detected in all lines were reliably detected in the pooled protein gels. We conclude that our pooling approach is a preferable approach to reliably detect a common protein expression pattern and may even allow proteomic analysis of clinical samples with limited amounts of sample material, even with minimal cell numbers as low as 1×106. [source]

Autoimmune and inflammatory disorders and risk of malignant lymphomas , an update

JOURNAL OF INTERNAL MEDICINE, Issue 6 2008
K. E. Smedby
Abstract. As specific autoimmune disorders now constitute established risk factors for malignant lymphomas, we describe this association. We review reported risk levels, risk determinants, lymphoma subtypes and biological mechanisms in autoimmunity/inflammation, emphasizing on recent findings. Whilst numerous reports describe average lymphoma risks in large patient groups, there's a recent shift of focus to risk determinants and the role of inflammatory activity. Studies highlight associations with diffuse large B-cell lymphoma, apart from lymphoma development in target organs of inflammation. Future studies of high-risk patient subsets using detailed assessments of autoimmunity/inflammation and lymphoma may give important clues to lymphomagenesis. [source]