[Comparative study of heterogeneity of extranodal and nodal diffuse large B cell lymphoma]

OBJECTIVE

Primary nodal and extranodal diffuse large B-cell lymphoma (DLBCL) were investigated for the heterogeneity of histopathology and immunophenotype, and their relation to clinical stage, comparatively. Whether E2F1 can be used as a germinal center B cell (GCB) DLBCL marker was also discussed.

METHODS

Classification of histopathology and immunophenotype of 98 cases were studied by immunohistochemistry in tissue microarray.

RESULTS

Histopathologic morphology presented as: centroblastic (CB,88.8%, 87/98), immunoblastic (IB,5.1%, 5/98), anaplastic (ALCL,3.1%, 3/98), and T cell rich B cell lymphoma (TCRBCL,3.1%, 3/98). Of which, 31 cases were GCB DLBCL, 10 (20.8%, 10/48) nodal, and 21 extranodal (42%, 21/50, P=0.024). The rates of Stages I/II in nodal and extranodal area were 48.5% and 70%, respectively (P=0.015). The rate of Stage I/ II in GCB DLBCL (74.2%) were higher than in non-GCB DLBCL (50.7%, P=0.029). The CD10 positive rates were 36.8% and 17.1% in Stages I/II and III/IV, respectively, and had significant differences (P=0.033). The CD10 positive rates were 18.8% and 38% in nodal and extranodal area, respectively (P=0.035). The positive rates of E2F1 were 38.8% and 16.5% in GCB and non-GCB DLBCL, respectively, and had significant differences (P=0.016). The positive rate of E2F1 had positive relation with the expression of CD10 and Bcl-6 (P<0.05).

CONCLUSION

CB is the most type in 98 cases of DLBCL. The rate of GCB DLBCL was significant higher in extranodal than in nodal areas CD 10 can be used as a prognostic marker. The prognosis of GCB DLBCL is better than that of non-GCB DLBCL. The positive expression of E2F1 can be used as a marker of GCB DLBCL.

Clinicopathologic correlations of stage IE/IIE primary thyroid diffuse large B-cell lymphoma

BACKGROUND

We studied the clinicopathological characteristics and prognoses of localized stage thyroid diffuse large B-cell lymphoma (DLBCL).

PATIENTS AND METHODS

This study included 32 patients with stage I/IIE thyroid DLBCL. Their median age was 66 years, the male/female ratio was 10/22.

RESULTS

As to the cellular immunophenotype, CD20 was positive in 31/32, CD5 in 0/32, CD10 in 4/32, CD23 in 1/32, BCL2 in 14/30, and BCL6 in 24/32. Twelve cases showed abnormal karyotypes: two cases with t(8;14)(q24;q32), four cases with 3q27, two cases with 17p11, and four cases with other abnormal karyotypes. As for treatment, eight cases were treated with chemotherapy alone and 24 cases were treated with chemotherapy followed by radiotherapy. Complete response was achieved in 94%. The 5-year progression-free survival was 84% and the 5-year overall survival was 90% with a median follow-up period of 62 months. The germinal center B-cell (GCB) type had a significantly better prognosis than the non-GCB type.

CONCLUSION

Localized stage thyroid DLBCL is a disease with a relatively good prognosis. It is, however, a heterogeneous disease with regard to histological type and pathological state. Localized stage thyroid DLBCL has a good prognosis and it is that there are more GCB-type DLBCL lymphomas.

CD30 Activates Both the Canonical and Alternative NF-κB Pathways in Anaplastic Large Cell Lymphoma Cells

CD30 is a member of the tumor necrosis factor receptor superfamily whose expression is up-regulated on anaplastic large cell lymphoma (ALCL) and Hodgkin lymphoma (HL) cells. Many different outcomes of CD30 stimulation have been reported, including cell cycle arrest, apoptosis, and activation of the prosurvival transcription factor, NF-kappaB, although this last activity is much less well defined in ALCL cells. In order to better understand the signaling properties of CD30 in cancer, we established a system for the stimulation of CD30 with its physiological ligand. Using this system, CD30 was stimulated on ALCL and HL cells, and the subsequent CD30 signaling properties were characterized. We show that a fraction of ALCL cells rapidly underwent apoptosis following CD30 stimulation, whereas HL cells were unaffected. The surviving ALCL cells exhibited robust activation of both the canonical and alternative NF-kappaB pathways as measured by nuclear translocation of RelA, p50, RelB, and p52, and this culminated in the transactivation of classical NF-kappaB-responsive genes. With prolonged CD30 stimulation, ALCL cells underwent cell cycle arrest that correlated with expression of the cell cycle inhibitor p21(waf1). Furthermore, p21(waf1) expression and cell cycle arrest were found to depend predominantly on the canonical NF-kappaB pathway, since it was reversed by RNA interference-mediated suppression of RelA. In contrast, suppression of the p100/p52 NF-kappaB subunit had little effect on p21(waf1). These data reveal that in ALCL cells, in contrast to other cell types, CD30 stimulation elicits p21(waf1)-mediated arrest through the canonical but not the alternative NF-kappaB pathway.

Microvessel density and expression of vascular endothelial growth factor and its receptors in diffuse large B-cell lymphoma subtypes

Angiogenesis is known to play a major role in neoplasia, including hematolymphoid neoplasia. We assessed the relationships among angiogenesis and expression of vascular endothelial growth factor and its receptors in the context of clinically and biologically relevant subtypes of diffuse large B-cell lymphoma using immunohistochemical evaluation of tissue microarrays. We found that diffuse large B-cell lymphoma specimens showing higher local vascular endothelial growth factor expression showed correspondingly higher microvessel density, implying that lymphoma cells induce local tumor angiogenesis. In addition, local vascular endothelial growth factor expression was higher in those specimens showing higher expression of the receptors of the growth factor, suggesting an autocrine growth-promoting feedback loop. The germinal center-like and nongerminal center-like subtypes of diffuse large B-cell lymphoma were biologically and prognostically distinct. Interestingly, only in the more clinically aggressive nongerminal center-like subtype were microvessel densities significantly higher in specimens showing higher vascular endothelial growth factor expression; the same was true for the finding of higher vascular endothelial growth factor receptor-1 expression in conjunction with higher vascular endothelial growth factor expression. These differences may have important implications for the responsiveness of the two diffuse large B-cell lymphoma subtypes to anti-vascular endothelial growth factor and anti-angiogenic therapies.

The impact of Epstein-Barr virus status on clinical outcome in diffuse large B-cell lymphoma

To define prognostic impact of Epstein-Barr virus (EBV) infection in diffuse large B-cell lymphoma (DLBCL), we investigated EBV status in patients with DLBCL. In all, 380 slides from paraffin-embedded tissue were available for analysis by EBV-encoded RNA-1 (EBER) in situ hybridization, and 34 cases (9.0%) were identified as EBER-positive. EBER positivity was significantly associated with age greater than 60 years (P = .005), more advanced stage (P < .001), more than one extranodal involvement (P = .009), higher International Prognostic Index (IPI) risk group (P = .015), presence of B symptom (P = .004), and poorer outcome to initial treatment (P = .006). The EBER(+) patients with DLBCL demonstrated substantially poorer overall survival (EBER(+) vs EBER(-) 35.8 months [95% confidence interval (CI), 0-114.1 months] vs not reached, P = .026) and progression-free survival (EBER(+) vs EBER(-) 12.8 months [95% CI, 0-31.8 months] vs 35.8 months [95% CI, 0-114.1 months], respectively (P = .018). In nongerminal center B-cell-like subtype, EBER in situ hybridization positivity retained its statistical significance at the multivariate level (P = .045). Nongerminal center B-cell-like patients with DLBCL with EBER positivity showed substantially poorer overall survival with 2.9-fold (95% CI, 1.1-8.1) risk for death. Taken together, DLBCL patients with EBER in situ hybridization+ pursued more rapidly deteriorating clinical course with poorer treatment response, survival, and progression-free survival.

Expression of the RNA-binding protein VICKZ in normal hematopoietic tissues and neoplasms

BACKGROUND AND OBJECTIVES

VICKZ family members are RNA-binding regulatory proteins expressed during embryogenesis but not usually found in normal adult tissue. The presence of VICKZ in normal germinal centers (GC) prompted us to characterize the expression pattern of this protein in lymphoid and hematopoietic tissues.

DESIGN AND METHODS

We generated a pan-VICKZ antibody that recognized all three isoforms of VICKZ protein and screened 889 patients' samples by immunohistologic methods. We also analyzed the expression of VICKZ in normal hematopoiesis tissue by staining samples of tonsils, lymph nodes

RESULTS

VICKZ protein expression was documented for the first time in normal human GC and in follicular (126/165), mediastinal large B-cell (9/10), Burkitt (2/2), diffuse large B-cell (DLBCL, 155/200), lymphocyte-predominant Hodgkin's (12/13), classical Hodgkin's (101/108), and anaplastic large cell (6/8) lymphomas and in lymphoid and myeloid leukemias. Since DLBCL may derive from GC or non-GC B cells we performed hierarchical cluster analysis for VICKZ, HGAL, BCL6, CD10, MUM1/IRF4 and BCL2 which showed that VICKZ is expressed in both subtypes. In addition, VICKZ mRNA isoforms were differentially expressed in lymphoma subtypes and over 40% of DLBCL expressed hVICKZ2, an isoform not usually present in normal GC B cells.

INTERPRETATION AND CONCLUSIONS

We show that in normal lymphoid tissues VICKZ is expressed in GC lymphocytes but in lymphoid neoplasms its expression is not limited to GC-derived lymphoma subtypes. However, VICKZ exhibits differential expression in lymphoma subtypes and thus may be a marker of potential value in the diagnosis and study of hematopoietic neoplasia. The aberrant expression of its isoforms in DLBCL raises the possibility that these isoforms may be associated with different functions and suggests that further study of their role in normal and neoplastic lymphoid cells is warranted.

Expression of transmembrane adaptor protein PAG/Cbp in diffuse large B-cell lymphoma: immunohistochemical study of 73 cases

PAG/Cbp is a transmembrane adaptor protein involved in proximal immune signaling. It is expressed in reactive germinal centers (GC) of secondary lymphatic follicles and related malignant lymphomas. We studied PAG/Cbp expression in GC-like and non-GC-like diffuse large B-cell lymphoma (DLBCL) subtypes. Seventy-three cases of DLBCL identified among 155 malignant lymphomas were classified as GC-like DLBCL (CD10+ or CD10-, bcl-6+, and MUM1-) and non-GC-like DLBCL (CD10-, MUM1+ or CD10-, bcl-6+, MUM1+). PAG/Cbp was detected by monoclonal antibody MEM-255 following routine immunohistochemical procedures. Thirty-five of 40 GC-like DLBCLs (88%) and 20 of 33 non-GC-like DLBCL cases (61%) expressed PAG/Cbp. Four of 12 bcl-6-negative non-GC-like DLBCL cases (33%) were PAG/Cbp positive, and only 4 of 20 bcl-6-positive non-GC-like DLBCL cases (25%) were PAG/CBP negative. All 37 FL and all 5 Burkitt's lymphomas (BL) expressed PAG/Cbp, whereas all 6 mantle cell lymphomas (MCL) and 4 of 5 chronic lymphocytic leukemias (CLL/SLL) were PAG/Cbp negative. PAG/Cbp is a reliable GC marker. Its expression correlates with GC-like DLBC phenotype in a significant majority of cases. It is typically absent in MCL and SLL/CLL.

Cytokine production by hepatic anaplastic large-cell lymphoma presenting as a rheumatic syndrome

OBJECTIVES

A variety of malignancies can present as rheumatic syndromes. Our aim was to describe a case of primary hepatic anaplastic large-cell lymphoma (ALCL) presenting as a rheumatic syndrome. We also describe cytokine production by the tumor.

METHODS

A patient with ALCL presenting with arthralgia and systemic inflammation is described. Cytokine production by the resected tumor and adjacent normal liver was assayed by enzyme-linked immunosorbent assay following in vitro culture. Medline database search of the English literature between 1976 and August 2006 was performed.

RESULTS

A 44-year-old man was admitted with generalized arthralgias, fatigue, weight loss, and night sweats. Despite a high clinical suspicion of underlying malignancy, repeated radiologically guided biopsies of bone and liver abnormalities failed to demonstrate any malignant cells. The patient improved dramatically on empirical corticosteroids but symptoms recurred on attempting to reduce the steroid dosage. He ultimately underwent partial hepatectomy for an enlarging liver lesion, which was demonstrated to be primary hepatic ALCL on immunohistochemistry. There are a few reports of ALCL presenting as bone lesions, but to our knowledge this is the first report of hepatic ALCL presenting with a rheumatic syndrome. The clinical and biochemical inflammation resolved following resection of the tumor but returned on tumor recurrence. The tumor produced large quantities of the proinflammatory cytokines interleukin-6 (IL-6) and IL-8 but did not produce tumor necrosis factor-alpha (TNF-alpha), IL-1, or IL-4.

CONCLUSIONS

Repeat biopsies may be required to diagnose underlying tumor. The ALCL tissue in our patient produced large quantities of the IL-6, which we believe was associated with the patient's systemic inflammation.

A case of primary unilateral adrenal Burkitt-like large cell lymphoma presenting as adrenal insufficiency

Primary adrenal lymphoma is extraordinarily rare, in comparison with secondary adrenal involvement by non-Hodgkin lymphoma. Although higher-resolution imaging techniques have enhanced detection of adrenal masses, biopsy or excision is often needed for definitive diagnosis. Percutaneous computed tomography-guided fine needle aspiration has great diagnostic value in the workup of adrenal masses, but is limited by sampling error and artifacts. Primary adrenal lymphoma most commonly manifests with diffuse large B-cell morphology. Burkitt-like large cell lymphoma morphology has been previously reported only once, to our knowledge. We report an 80-year-old man presenting with unilateral primary adrenal lymphoma showing Burkitt-like morphology and adrenal insufficiency. Fine needle aspiration yielded a dispersed population of monomorphic, medium to large cells suggestive of lymphoma. Although dispersed cell populations cytologically favor lymphoma, metastatic poorly differentiated carcinoma and adrenal cortical carcinoma can manifest similarly. Integrated histological, immunohistochemical, and flow cytometric immunophenotyping would provide an accurate and definitive diagnosis. We review the literature and discuss important issues with regard to diagnosis.

Lipid peroxidation dominates the chemistry of DNA adduct formation in a mouse model of inflammation

In an effort to define the prevalent DNA damage chemistry-associated chronic inflammation, we have quantified 12 DNA damage products in tissues from the SJL mouse model of nitric oxide (NO) overproduction. Using liquid chromatography-mass spectrometry/MS and immunoblot techniques, we analyzed spleen, liver and kidney from RcsX-stimulated and control mice for the level of the following adducts: the DNA oxidation products 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), guanidinohydantoin (Gh), oxazolone (Ox); 5-guanidino-4-nitroimidazole (NitroIm); spiroiminodihydantoin (Sp) and M(1)dG; the nitrosative deamination products 2'-deoxyxanthosine, 2'-deoxyoxanosine (dO), 2'-deoxyinosine and 2'-deoxyuridine and the lipid peroxidation-derived adducts 1,N(6)-etheno-deoxyadenosine and 1,N(2)-etheno-deoxyguanosine. The levels of dO, Gh, Ox, NitroIm and Sp were all below a detection limit of approximately 1 lesion per 10(7) bases. Whereas there were only modest increases in the spleens of RcsX-treated compared with control mice for the nucleobase deamination products (10-30%) and the DNA oxidation products 8-oxodG (10%) and M(1)dG (50%), there were large (3- to 4-fold) increases in the levels of 1,N(6)-etheno-deoxyadenosine and 1,N(2)-etheno-deoxyguanosine. Similar results were obtained with the liver and with an organ not considered to be a target for inflammation in the SJL mouse, the kidney. This latter observation suggests that oxidative and nitrosative stresses associated with inflammation can affect tissues at a distance from the activated macrophages responsible for NO overproduction during chronic inflammation. These results reveal the complexity of NO chemistry in vivo and support an important role for lipids in the pathophysiology of inflammation.

TPM3-ALK expression induces changes in cytoskeleton organisation and confers higher metastatic capacities than other ALK fusion proteins

Translocations of the anaplastic lymphoma kinase (ALK) gene result in the production of a number of oncogenic ALK fusion proteins implicated in tumour development. We have previously shown that X-ALK fusion proteins have differential effects on the proliferation, transformation, and invasion properties of NIH3T3 cells in vitro. In the present study, we have investigated the metastatic potential of various X-ALK expressing cell lines using an experimental lung metastasis assay. We have shown that TPM3-ALK expression bestows higher metastatic capacities than other X-ALK fusion proteins and in addition, that TPM3-ALK fusion protein expression specifically induces changes in cell morphology and cytoskeleton organisation. Co-immunoprecipitation studies demonstrate a specific interaction between TPM3-ALK and endogenous tropomyosin. Together the specific actions of TPM3-ALK on the cytoskeleton organisation offer an interesting hypothesis with respect to the higher cell motility and metastatic potential of this fusion protein.

Primary cardiac plasmablastic (diffuse large B-cell) lymphoma mimicking left ventricular aneurysm with mural thrombus

Primary cardiac lymphoma is rare and is usually of the non-Hodgkin type. By definition, it involves only the heart and the pericardium, with no evidence of extracardiac disease. Primary cardiac lymphoma accounts for 1% of primary cardiac tumors and 0.5% of extranodal lymphomas [Gowda RM, Kahn RA. Clinical perspectives of primary cardiac lymphoma. Angiology 2003;54(5):599-604]. On the other hand, secondary cardiac involvement can occur in approximately 20% of patients with disseminated extracardiac lymphoma [Gowda RM, Kahn RA. Clinical perspectives of primary cardiac lymphoma. Angiology 2003;54(5):599-604]. The majority of primary cardiac lymphomas are diffuse large B-cell lymphomas with centroblastic or immunoblastic cytologic features. Herein, we describe an exceptional case of a primary cardiac plasmablastic variant of diffuse large B-cell lymphoma (Epstein-Barr virus-positive) presenting in an immunocompetent host with chest pain that mimicked a left ventricular apical thrombus.

CD4 T-Helper Responses to the Anaplastic Lymphoma Kinase (ALK) Protein in Patients with ALK-Positive Anaplastic Large-Cell Lymphoma

We have previously shown both humoral and CTL responses to anaplastic lymphoma kinase (ALK) in patients with ALK-positive anaplastic large-cell lymphoma (ALCL). However, because CD4(+) T-helper (Th) cells also play a vital role in developing and maintaining tumor immunity, we investigated the presence of a CD4(+) Th response in ALK-positive ALCL. Using an IFN-gamma ELISPOT assay, we identified two ALK-derived DRB1-restricted 24-mer promiscuous peptides, ALK1(278-301) and ALK2(233-256), as being immunogenic in six ALK-positive ALCL patients but not in two ALK-negative ALCL patients or five normal subjects. A significant interleukin-4 response to the ALK peptides was detected in only one ALK-positive patient. CD4(+) Th cell lines lysed ALK-positive ALCL cell lines in a MHC class II-restricted manner. This first report of a CD4(+) Th response to ALK provides valuable information for developing future immunotherapeutic options for ALK-positive ALCL patients who fail to respond well to conventional therapies.

Neutrophil-derived APRIL concentrated in tumor lesions by proteoglycans correlates with human B-cell lymphoma aggressiveness

A PRoliferation-Inducing TNF Ligand (APRIL) costimulates B-cell activation. When overexpressed in mice, APRIL induces B-cell neoplasia, reminiscent of human B-cell chronic lymphoid leukemia (B-CLL). We analyzed APRIL expression in situ in human non-Hodgkin lymphomas. APRIL up-regulation was only observed in high-grade B-cell lymphomas, diffuse large B-cell lymphoma (DLBCL), and Burkitt lymphoma (BL). Up-regulation was seen in 46% and 20% of DLBCL and BL, respectively. In DLBCL, neutrophils, constitutively producing APRIL and infiltrating the tumor tissue, were the main cellular source of APRIL. Rare DLBCL cases showed a predominance of histiocytes or mesenchymal cells as APRIL source. APRIL secreted by neutrophils accumulated on tumor cells via proteoglycan binding. In addition to proteoglycans, DLBCL tumor cells expressed the APRIL signaling receptor, TACI and/or BCMA, indicating that these tumor cells are fully equipped to respond to APRIL. A retrospective clinical analysis revealed a significant correlation between high expression of APRIL in tumor lesions and decreased overall patient survival rate. Hence, APRIL produced by inflammatory cells infiltrating lymphoma lesions may increase tumor aggressiveness and affect disease outcome.

DNA methylation profiling of transcription factor genes in normal lymphocyte development and lymphomas

Transcription factors play a crucial role during hematopoiesis by orchestrating lineage commitment and determining cellular fate. Although tight regulation of transcription factor expression appears to be essential, little is known about the epigenetic mechanisms involved in transcription factor gene regulation. We have analyzed DNA methylation profiles of 13 key transcription factor genes in primary cells of the hematopoietic cascade, lymphoma cell lines and lymph node biopsies of diffuse large B-cell- and T-cell-non-Hodgkin lymphoma patients. Several of the transcription factor genes (SPI1, GATA3, TCF-7, Etv5, c-maf and TBX21) are differentially methylated in specific cell lineages and stages of the hematopoietic cascade. For some genes, such as SPI1, Etv5 and Eomes, we found an inverse correlation between the methylation of the 5' untranslated region and expression of the associated gene suggesting that these genes are regulated by DNA methylation. Differential methylation is not limited to cells of the healthy hematopoietic cascade, as we observed aberrant methylation of c-maf, TCF7, Eomes and SPI1 in diffuse large B-cell lymphomas. Our results suggest that epigenetic remodelling of transcription factor genes is a frequent mechanism during hematopoietic development. Aberrant methylation of transcription factor genes is frequently observed in diffuse large B-cell lymphomas and might have a functional role during tumorigenesis.

[Detection of t (14; 18) translocation and bcl-2 amplification in diffuse large B-cell lymphoma]

OBJECTIVE

To investigate the role of t (14; 18) chromosomal translocation and bcl-2 amplification in classification, clinical staging and prognostic evaluation of diffuse large B cell lymphoma (DLBCL).

METHODS

Sixty cases of DLBCL were included in this investigation. Microdissection of the lymphoma tissue was performed. Tissue microarray and in-situ fluorescence hybridization technique were used to detect t (14; 18) and bcl-2 amplification. The phenotypes of either germinal center B-cell-like (GCB) or non-germinal center B-cell-like (non-GCB) were determined by immunohistochemistry including CD20, CD10, bcl-6 and MUM1 (S-P method) using the tissue microarray format. Clinical staging and therapeutic response were obtained by medical record review. The relationships among different parameters were analyzed by appropriate statistical methods.

RESULTS

Among 60 cases of DLBCL, bcl-2/IgH was positive in 10 cases and bcl-2 gene amplification was detected in 18 cases. Overall, 29 (48.3%) cases were GCB and 31 (51.7%) cases were non-GCB. The t (14; 18) was seen in 8 (80.0%) cases of GCB and 2 (20.0%) of non-GCB. The difference was statistical significance (P = 0.031). Over-expression of bcl-2 was seen in all cases having both t (14; 18) and bcl-2 gene amplification. Of thirty-six patients who underwent routine CHOP treatment, bcl-2 gene amplification was seen in 13 cases. In these cases, the rates of complete remission, partial remission and no change were 3 (23.1%), 4 (30.8%) and 6 (46.2%) respectively, and the clinical stages were stage I - II (1 case, 7.7%) and stage III - IV (12 cases, 92.3%). The clinical stages and therapeutic response were significantly different between the bcl-2 amplification cases and those without (P = 0.046 and P = 0.019, respectively).

CONCLUSIONS

T (14; 18) and/or bcl-2 gene amplification can lead to an over-expression of bcl-2 protein. The bcl-2 gene amplification correlates with worse therapeutic efficacies and advanced clinical stages. The reason for the correlation between bcl-2 over-expression and the prognosis is unclear, although it may be explained by different mechanisms that lead to bcl-2 over-expression. Detection of t (14; 18) chromosome translocation by FISH can be helpful in the classification of DLBCL.

Gene expression analysis of gallium-resistant and gallium-sensitive lymphoma cells reveals a role for metal-responsive transcription factor-1, metallothionein-2A, and zinc transporter-1 in modulating the antineoplastic activity of gallium nitrate

Several clinical trials have shown gallium nitrate to be an active agent in the treatment of lymphoma. Whereas gallium is known to target cellular iron homeostasis, the basis for lymphoma cell resistance to gallium is not known. Understanding mechanisms of resistance may suggest strategies to enhance the clinical efficacy of gallium. In the present study, we used a focused DNA microarray to compare the expression of genes related to metal metabolism in gallium-resistant and gallium-sensitive lymphoma cell lines developed by us. Gallium-resistant cells were found to display a marked increase in gene expression for metallothionein-2A and the zinc transporter ZnT-1. Cells exposed to gallium nitrate displayed an increase in the binding of metal-responsive transcription factor-1 to metal response element sequences involved in the transcriptional regulation of metallothionein and ZnT-1 genes. Gallium nitrate induced metallothionein-2A and ZnT-1 expression in cells. A role for metallothionein in modulating the antineoplastic activity of gallium was confirmed by showing that the induction of metallothionein expression by zinc provided partial protection against the cytotoxicity of gallium and by showing that the level of endogenous metallothionein in lymphoma cell lines correlated with their sensitivity to gallium nitrate. Immunohistochemical staining of lymphomatous tissues revealed metallothionein protein to be variably expressed in different lymphomas. Our studies show for the first time that gallium acts on pathways related to zinc metabolism and that metal-responsive transcription factor-1 activity and metallothionein expression contribute to the development of gallium drug resistance. Furthermore, the endogenous level of metallothionein in lymphoma may be an important determinant of clinical response to gallium nitrate.

[Clinicopathologic features, prognosis and etiology of primary non-Hodgkin lymphoma of bone]

OBJECTIVE

To study the clinicopathologic features, prognostic indicators and possible etiology of primary non-Hodgkin lymphoma of bone (PNHLB).

METHODS

The clinicopathologic features of 17 cases of PNHLB were reviewed. In-situ hybridization for Epstein-Barr virus early RNA (EBER) and polymerase chain reaction for bcl-2/JH gene rearrangement were performed using paraffin-embedded materials. The correlation between serum lactic dehydrogenase level, treatment options, international prognostic indicator (IPI) and immunophenotype with clinical outcome were analyzed.

RESULTS

The majority of the 17 cases studied was diffuse large B-cell lymphoma (94.1%). The 5-year survival rate was 68.8%. Unfavorable prognostic factors included high-risk IPI (P = 0.031) and bcl-2 overexpression (P = 0.028). Treatment options and expression of CD10, MUM-1 or bcl-6 did not correlate with clinical outcome (P > 0.05). Only 1 patient was positive for EBER, as demonstrated by in-situ hybridization.

CONCLUSIONS

The clinical outcome of PNHLB is relatively favorable. IPI and bcl-2 expression may serve as useful prognostic indicators. EBV is likely not related to pathogenesis of this type of lymphoma.

Clinical quantitation of diagnostic and predictive gene expression levels in follicular and diffuse large B-cell lymphoma by RT-PCR gene expression profiling

Recent microarray gene expression profiling studies have identified gene signatures predictive of outcome, so-called "indicator" genes, for diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). However, measurement of these genes in routine practice remains difficult. We applied real-time polymerase chain reaction (PCR) to polyA cDNAs prepared from 106 archived human frozen lymph nodes (63 of FL, 25 of DLBCL, 10 reactive lymph nodes, and cases with paired samples of FL [4] and subsequent DLBCL [4]). Reverse transcription and polyA reverse transcriptase (RT)-PCR was performed, and resultant cDNA was probed by real-time PCR for 36 candidate indicator genes, selected from microarray studies. Nine genes showed statistically significant different expression between FL and DLBCL, including cyclin B, COL3A1, NPM3, H731, PRKCB1, OVGL, ZFPC150, HLA-DQ-a, and XPB. Of these, cyclin B, NPM3, and COL3A1 were higher in DLBCL. Six genes showed statistically significant higher expression in the neoplastic nodes compared with reactive nodes, namely PRKCB1, BCL-6, EAR2, ZFX, cyclin B, YY1. High levels of YY.1 were associated with a shorter survival interval in both FL and DLBCL. The method is simple, sensitive, and robust, facilitating routine use and may be used as a platform for clinical measurement of prognostic gene signatures.

CD26, together with cell surface adenosine deaminase, is selectively expressed on ALK-positive, but not on ALK-negative, anaplastic large cell lymphoma and Hodgkin's lymphoma

CD26/dipeptidyl peptidase IV is a cell surface antigen with multiple biological functions. Although its involvement in tumor biology has been suggested, the significance of its expression in malignant lymphoma has not been clarified in detail. This study examined the expression of CD26 and cell surface adenosine deaminase (ADA) in 42 cases of Hodgkin's lymphoma (HL) and T-cell lymphoma by immunohistochemistry on frozen sections. CD26 was expressed in three of 14 cases of HL, in four of eight cases of anaplastic large cell lymphoma (ALCL), in two of nine cases of peripheral T-cell lymphoma, in one of six cases of lymphoblastic lymphoma and in none of three cases of adult T-cell lymphoma/leukemia. Expression of cell surface ADA was fully correlated with the expression of CD26 and expression of CD26/ADA in ALCL and HL was also completely correlated with the expression of p80 and epithelial membrane antigen. Of 10 CD26-positive patients, seven had fever and elevated CRP at initial diagnosis and over a median follow-up of 61 months (range, 7 - 152 months) only three survived. This study suggested that CD26 is selectively expressed on ALK-positive, but not on ALK-negative, ALCL and HL. This is also the first report to demonstrate that ADA is coexpressed with CD26 on the cell surface of malignant neoplasms in vivo.

A case of T/null anaplastic large cell lymphoma arising in lung

Anaplastic large cell lymphoma (ALCL) is a rare non-Hodgkin, T-cell lymphoma, representing only 2-3% of all lymphoid neoplasm's in adults according to World Health Organization (WHO). CD30 antigen-positive, large neoplastic cells characterize ALCL. We present here a 46-year-old male with pulmonary ALCL previously diagnosed with Hodgkin disease. Microscopically, atypical bi-and multinucleated cells with frequent mitoses were present. The neoplastic cells were large and had clear cytoplasm, large vesicular nuclei, and prominent nucleoli. Immunophenotypic analysis revealed LCA, vimentin and CD30 positivity. ALK immunostaining was negative. Immunohistochemical profile was consistent with ALK negative ALCL. The progression of Hodgkin lymphoma to aggressive non-Hodgkin lymphoma (ALCL in this case) is well known entity. After the diagnosis was established, our patient immediately had been referred to the Department of Hematology in order to get appropriate chemotherapy, necessary in such cases.

Expression of TRAF1 and Nuclear c-Rel Distinguishes Primary Mediastinal Large Cell Lymphoma From Other Types of Diffuse Large B-cell Lymphoma

Primary mediastinal large B-cell lymphoma (PMLBCL) is a recently identified subtype of diffuse large B-cell lymphoma (DLBCL) that is difficult to distinguish from other types of DLBCL on the basis of histologic features alone. We recently identified a molecular signature of PMLBCL that is distinct from other forms of DLBCL but shares features with classical Hodgkin lymphoma. This signature includes activation of the nuclear factor kappaB (NFkappaB) signaling pathway, which in part, acts through nuclear translocation of c-Rel containing NFkappaB transcriptional complexes, and subsequent expression of NFkappaB target genes such as tumor necrosis factor receptor-associated factor-1 (TRAF1). Using standard immunohistochemical techniques, we examined 251 large B-cell lymphomas (78 cases of PMLBCL and 173 cases of other types of DLBCL) to determine whether the expression patterns of c-Rel and TRAF1 could reliably distinguish between PMLBCL and other types of DLBCL. Robust nuclear c-Rel was present in 31 of 48 (65%) cases of PMLBCL and 28 of 160 (18%) cases of DLBCL. In addition, cytoplasmic TRAF1 expression was seen in 48 of 78 (62%) cases of PMLBCL, but only 20 of 173 (12%) cases of DLBCL. Finally, the combined expression of nuclear c-Rel and TRAF1 was seen in 24 of 45 cases (53%) of PMLBCL, but in only 3 of 156 cases (2%) of other types of DLBCL. Thus, the combined nuclear localization of c-Rel and the cellular expression of TRAF1 is a highly specific (specificity=98%) means to distinguish PMLBCL from DLBCL that is readily applicable to routine surgical pathology practice.