FOXO1 is a TXN- and p300-dependent sensor and effector of oxidative stress in diffuse large B-cell lymphomas characterized by increased oxidative metabolism.

Molecular profiling has led to identification of subtypes of diffuse large B-cell lymphomas (DLBCLs) differing in terms of oncogenic signaling and metabolic programs. The OxPhos-DLBCL subtype is characterized by enhanced mitochondrial oxidative phosphorylation. As increased oxidative metabolism leads to overproduction of potentially toxic reactive oxygen species (ROS), we sought to identify mechanisms responsible for adaptation of OxPhos cells to these conditions. Herein, we describe a mechanism involving the FOXO1-TXN-p300 redox-dependent circuit protecting OxPhos-DLBCL cells from ROS toxicity. We identify a BCL6-dependent transcriptional mechanism leading to relative TXN overexpression in OxPhos cells. We found that OxPhos cells lacking TXN were uniformly more sensitive to ROS and doxorubicin than control cells. Consistent with this, the overall survival of patients with high TXN mRNA expression, treated with doxorubicin-containing regimens, is significantly shorter than of those with low TXN mRNA expression. TXN overexpression curtails p300-mediated FOXO1 acetylation and its nuclear translocation in response to oxidative stress, thus attenuating FOXO1 transcriptional activity toward genes involved in apoptosis and cell cycle inhibition. We also demonstrate that FOXO1 knockdown in cells with silenced TXN expression markedly reduces ROS-induced apoptosis, indicating that FOXO1 is the major sensor and effector of oxidative stress in OxPhos-DLBCLs. These data highlight dynamic, context-dependent modulation of FOXO1 tumor-suppressor functions via acetylation and reveal potentially targetable vulnerabilities in these DLBCLs.

IL-10 promoter polymorphisms influence susceptibility to aGvHD and are associated with proportions of CD4+FoxP3+ lymphocytes in blood after hematopoietic stem cell transplantation.

Four hundred and ninety-five patients (390 and 105 grafted from unrelated and sibling (SIB) donors, respectively) and their donors were analyzed for the impact of interleukin-10 (IL-10) promoter genotype [rs18000896 (-1082 G/A), rs18000871 (-819 C/T) and rs18000872 (-592 C/A)] on the outcome of hematopoietic stem cell transplantation (HSCT). Patients having ACC haplotype were at a lower risk of acute graft versus host disease (aGvHD, grade > I) if transplanted from human leukocyte antigen (HLA) well-matched (10/10) unrelated donors (20/135 vs 39/117, P < 0.001, Pcorr = 0.002), which was not seen if patients were transplanted from either sibling (SIB) or poorly matched (<10/10) unrelated donors (MUD). In addition, GCC haplotype positive recipients of unrelated donor transplants tended to be more susceptible to aGvHD (68/199 vs 39/169, P = 0.019, Pcorr = 0.057). Multivariate logistic regression analysis in the MUD transplanted group showed that donor-recipient human leukocyte antigen (HLA) mismatch [odds ratio (OR) = 3.937, P = 0.001] and a lack of ACC haplotype in recipients (OR = 0.417, P = 0.013) played a significant role as independent risk factors of aGvHD grade > I. ACC carriers had higher proportions of FoxP3+ lymphocytes gated in CD4+ lymphocytes as compared with patients with other IL-10 haplotypes. It was seen at the time of hematological recovery (mean ± SEM: 3.80 ± 0.91% vs 2.06 ± 0.98%, P = 0.012) and 2 weeks later (5.32 ± 0.87% vs 2.50 ± 0.83%, P = 0.013); -592 C/A polymorphism was separately analyzed and it was found that AA homozygotes tended to have a higher incidence of aGvHD (8/15 vs 116/456, P = 0.034) and low proportions of FoxP3 CD4+ lymphocytes in blood (0.43 ± 0.22% vs 4.32 ± 0.71%, P = 0.051) measured 2 weeks after hematological recovery. Functional IL-10 polymorphism associated features influenced the risk of aGvHD with a positive effect of ACC on the pool of Treg in blood.

Haplotype-specific pattern of association of human major histocompatibility complex with non-Hodgkin's lymphoma outcome.

In the previous studies, some human major histocompatibility complex (MHC) genes such as TNF, LTA and human leukocyte antigen (HLA)-DR2 genes and A1-B8-TNF(-308A) haplotype were implied in non-Hodgkin's lymphoma (NHL) outcome. In the current study, we have assigned most probable six-locus haplotypes determined by HLA-A, -Cw, -B and -DRB1 highly polymorphic genes and non-HLA LTA(+252) and TNF(-308) single nucleotide polymorphisms (SNPs) in 152 NHL Caucasian French patients. We have broadly mapped the MHC region by its component blocks and tagging alleles. Ten frequent (with haplotype frequency >1%) six-locus extended haplotypes (EHs) were revealed in NHL patients. The only two adjacent locus fragment of 8.1 EH associated with shortened freedom from progression (FFP) was B*08-LTA(+252G) (P= 0.0084, RR = 2.45). Interestingly, 305-kbp-long, four-locus fragment of 8.1 EH, Cw*07-B*08-LTA(+252G)-TNF(-308A) block was much strongly associated with shortened FFP (P= 0.00045, RR = 3.26). The analysis of further extended haploblocks comprising five or six loci showed weaker association with outcome measures, suggesting linkage disequilibrium to be the cause of DRB1*03 and A*01 allele associations. In contrast, all fragments of 7.1 EH influenced FFP favorably with top association of TNF(-308G) allele. In multivariate analysis, only Cw*07-B*08-LTA(+252G)-TNF(-308A) and TNF(-308G)-DRB1*01 haplotypes remained predictive for shortened FFP (P= 0.024 and 0.027, respectively) and independent of International Prognostic Index (P= 0.00044). This study reveals that the block composition of EHs may cause important functional differences for NHL outcomes. Further study will be required in NHL patients by fine mapping with dense microsatellite or SNP tags to define susceptibility genes in associating regions.

The influence of palifermin (Kepivance) on oral mucositis and acute graft versus host disease in patients with hematological diseases undergoing hematopoietic stem cell transplant.

In this multicenter study, we assessed the use of palifermin (recombinant human-keratinocyte growth factor 1) in the prevention of oral mucositis (OM) and acute GvHD (aGvHD) induced by a hematopoietic stem cell transplant (HSCT). Fifty-three patients with hematological diseases received three doses of palifermin (60 mug/kg once daily i.v.) pre- and post-conditioning regimens (total six doses). A retrospective control group of 53 transplant patients received no palifermin. There was a significant reduction in the incidence of OM of WHO (World Health Organization) grades 1-4 (58 vs 94%, P<0.001), 3-4 (13 vs 43%, P<0.001) and the median duration of OM (4 vs 9 days, P<0.001) in the palifermin group compared to the control group. The incidence of analgesics (32 vs 75.5%, P<0.001), opioid analgesics (24 vs 64%, P<0.001) and total parenteral nutrition (11 vs 45%, P<0.001) was also significantly reduced. The analysis of distribution of affected organs revealed that aGvHD was less prevalent in the palifermin group (P=0.036). There was no significant difference in the onset of any OM after HSCT, time to engraftment and length of hospitalization between groups. The drug was generally well tolerated and safe. Our results suggest that the use of palifermin reduces OM and probably aGvHD after HSCT, but a randomized trial is needed.

Outcome and prognostic factors in advanced Hodgkin's disease treated with high-dose chemotherapy and autologous stem cell transplantation: a study of 341 patients.

BACKGROUND: The reported probability of survival of patients with Hodgkin's disease (HD) following high-dose chemotherapy with autologous stem cell transplantation (HDC/ASCT) is 35-65% at 5 years. The Polish Lymphoma Research Group investigated retrospectively prognostic factors for overall survival (OS) and event-free survival (EFS), and the risk of secondary malignancies in a large series of patients who underwent HDC/ASCT. PATIENTS AND METHODS: The data of 341 consecutive patients treated in 10 centers from 1990 to 2002 were collected and analyzed. RESULTS: The actuarial 5-year OS and EFS were 64% [95% confidence interval (CI) 57% to 71%] and 45% (95% CI 39% to 51%), respectively. In the multivariate model, unfavorable prognostic factors for EFS were less than partial response at the time of ASCT [relative risk (RR), 2.92 (95% CI 1.68-5.08); P<0.001] and three or more previous chemotherapy lines (RR, 2.16; 95% CI 1.42-3.30; P<0.001). These two factors were also associated with unfavorable OS (RR, 3.32; 95% CI 1.90-5.79; P<0.001 and RR, 2.34, 95% CI 1.51-3.64; P<0.001). Five-year cumulative risk of secondary malignancy was 8.4% (95% CI 2% to 13%) and the only identified risk factor was splenectomy (P=0.02). CONCLUSIONS: HDC/ASCT should be considered early in the course of disease for patients with a response after standard therapy.

High-dose chemotherapy with autologous stem cell transplantation is an effective treatment of primary refractory Hodgkin's disease. Retrospective study of the Polish Lymphoma Research Group.

We analysed the treatment outcome of primary refractory HD patients managed with high-dose chemotherapy and haematopoietic cell transplantation. Data of 65 adult patients who underwent HDC/ASCT in nine Polish centres for primary resistant Hodgkin's disease between June 1991 and July 2000 were collected retrospectively. Response rate to HDC/ASC: CR, 54%; PR, 20%; less than PR, 15%; early deaths, 11%. Actuarial 3-year OS and PFS were 55% and 36%, respectively. In multivariate analysis, lack of bulky lymph nodes and use of immunotherapy were favourable factors for both OS and PFS. IPF <3 at the time of transplantation was predictive for PFS. However, the prognostic impact of immunotherapy should be interpreted with caution since this group included more patients who achieved CR after HDC/ASCT. The results of HDC/ASCT are encouraging and confirm earlier findings. The role of immunotherapy should be further investigated in prospective trials.

Diagnostic and therapeutic quandaries in primary manifestation of Hodgkin's disease in the central nervous system.

We report the case of a 23-year-old female with severe neurologic dysfunction without a clear cause at the time of initial presentation. The search for an underlying malignancy revealed a slightly enlarged cervical lymph node with Hodgkin's disease (HD). There was no evidence of a brain tumor despite nonspecific bright changes in proton density in the basal ganglia of the right hemisphere of the cerebellum, right cerebellar tonsil, posterior limb of the internal capsule, and the right side of the medulla spinae as shown by magnetic resonance imaging (MRI) as well as reactive lymphocytosis with slightly elevated protein levels in the cerebrospinal fluid (CSF). The findings suggested a cerebellar disorder, with main differential diagnosis between neurologic paraneoplastic syndrome (NPS) and HD involving the CNS. Based on limited experience with NPS and HD in the CNS, possible diagnostic and therapeutic options are discussed.

Rituximab (Mabthera, Rituxan) in patients with recurrent indolent lymphoma: evaluation of safety and efficacy in a multicenter study.

The objective of this multiinstitutional study was to evaluate the safety and efficacy of rituximab at standard four weekly doses in patients with recurrent indolent lymphoma. Thirty-eight patients entered into this study, 63% had follicular lymphoma and 61% had an IPI score of 2 or more. Median disease duration was 3 yr, median number of prior treatments was three, and 66% of patients responded to the immediate past treatment with a median remission duration of 3 mo. A total of 158 antibody doses were given, including two patients who received two courses of four infusions each. One patient developed acute respiratory failure after the second dose and required assisted ventilation. There was no immediate relationship to the antibody infusion and no evidence of infection. This complication resolved and the patient successfully completed the full course of the antibody treatment. Another patient discontinued therapy after the second dose owing to intolerable fever and painful erythema. Sixty percent of the first, and 20% of subsequent rituximab infusions were associated with infusion-related reactions including mild fever, chills, and occasional skin eruptions. Complete and partial responses were achieved in 24% and 35% of 34 evaluable patients, respectively, for an overall response rate of 59%. The median time to progression/relapse in responding patients was 16 mo (95% CI, 6.4, 25.6) compared with a median of 3 mo duration of response to the immediate previous therapy in these patients. Longer response duration post rituximab monotherapy than with previous treatment in this series of heavily pretreated patients suggests a major role for the antibody in the therapy of patients with indolent lymphoma.

Plasmablastic lymphoma in a patient with chronic lymphocytic leukemia heavily pretreated with cladribine (2-CdA): an unusual variant of Richter's syndrome.

Patients with chronic lymphocytic leukemia (CLL) may develop a large-cell transformation known as Richter's syndrome (RS). RS usually presents as diffuse large-cell lymphoma (DLCL) or its immunoblastic variant, and it can be recognized simultaneously with CLL or even 23 yr after its diagnosis. We describe an unusual case of CLL treated with cladribine (2-CdA) in whom DLCL of the plasmablastic type (PBL) developed 4 yr after CLL (Rai IV) diagnosis and 1.5 yr after the 10th course of 2-CdA treatment. Immmunologic, cytogenetic, and molecular studies performed at the time of CLL and PBL coappearance indicated that both tumors originated from different B-cell progenitors. Both malignancies were refractory to VAD (vincristine, doxorubicin, dexamethasone)-based chemotherapy, and only partial response was achieved with CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) salvage treatment. However, the patient died 6 months after the occurrence of RS due to rapid progression of PBL. This is the first description of a CLL patient who developed an unusual plasmablastic variant of RS. Recently, the PBL entity has been identified among DLCL associated with the human immunodeficiency virus (HIV) infection. We suggest that in our CLL patient heavily pretreated with 2-CdA, PBL arose as a second clone due to the prolonged and severe state of the host's immunosuppression. Overall survival with current strategies is poor, and further insight into the natural history, biology, and treatment of PBL are needed.

Expression of genes coding for the tumor necrosis factor and lymphotoxin ligand-receptor system in non-Hodgkin's lymphomas.

Excessive production of the tumor necrosis factor (TNF) ligand-receptor system has been found to contribute to the severity of non-Hodgkin's lymphoma (NHL). We therefore investigated the expression of TNF, lymphotoxin alpha (LTalpha), lymphotoxin beta (LTbeta), and their receptor (p55, p75, LTbeta-R) transcripts within the tumor tissue in different NHL histological subtypes. The constitutive expression of genes coding for TNF-related ligands and receptors was found in almost all 31 NHL samples studied. Semi-quantitative reverse transcription/polymerase chain reaction and computed densitometry assays revealed that the amounts of TNF, LTalpha, p55, and LTbeta-R mRNA were higher in follicular NHL than in other histological entities. Therefore tumor cell immunopurification was performed in representative follicular NHL samples and consistent results were obtained. The pattern of LTbeta gene expression was different from that of the other molecules, indicating the existence of distinct mechanisms of gene regulation. These results indicate that the transcription of genes coding for the TNF ligand-receptor system in NHL tumor tissue is more widespread than originally thought and that the heterogeneity of their expressions might be related to histological features. The expression of TNF-related ligands and receptors in tumor tissues is likely to contribute to the clinicopathological features of lymphoid-derived malignancies.

Factors that predict chemotherapy-induced myelosuppression in lymphoma patients: role of the tumor necrosis factor ligand-receptor system.

PURPOSE: To analyze factors that predict the occurrence of chemotherapy-induced myelosuppression and, in particular, the role of the tumor necrosis factor (TNF) ligand-receptor system in lymphoma patients at the beginning of their treatment. PATIENTS AND METHODS: We investigated the predictive factors for myelosuppression after the first course of chemotherapy in a cohort of 101 consecutive, previously untreated lymphoma patients receiving regimens that include doxorubicin and cyclophosphamide. Plasma samples were tested at baseline by enzyme-linked immunosorbent assay for TNF and its soluble receptors. Univariate and multivariate analyses were performed with a forward regression procedure that included all of the parameters that were found to be significant in the univariate analysis. The dose of chemotherapy and the prophylactic treatment with granulocyte colony-stimulating factor were deliberately included in this model. RESULTS: Sixty-seven patients experienced World Health Organization (WHO) grade 4 neutropenia, and 37 patients experienced febrile neutropenia, which was responsible for WHO grade 2 through 4 infections in 23 patients. In multiparametric regression analysis, the occurrence of grade 4 neutropenia was associated with high doses of cyclophosphamide (odds ratio ¿OR, 19.8; P =.008) and high levels of soluble p75-R-TNF (OR, 8.52; P =.001). The duration of grade 4 neutropenia for more than 5 days was associated with the lack of hematopoietic growth factor administration (OR, 6.76; P =.004) and high levels of soluble p75-R-TNF (OR, 5.84; P =.0023). The occurrence of febrile neutropenia was associated with high doses of cyclophosphamide (OR, 4.7; P =.007), altered performance status (OR, 18.8; P <.0001) and high levels of soluble p75-R-TNF (OR, 3.49; P =.029). CONCLUSION: This study indicates that in addition to the dose of chemotherapy and the administration of hematopoietic growth factors, poor performance status and high p75-R-TNF levels can predict the occurrence of chemotherapy-induced myelosuppression in lymphoma patients. This model may help in selecting patients for prophylactic growth factor administration.

Antisense strategy in hematological malignancies.

Standard cytotoxic chemotherapy for neoplastic disease is fraught with systemic toxicity. The ratio of the toxic dose to the therapeutic dose is relatively low, which reflects the large number of cellular targets affected by the chemotherapeutic agent as well as its inability to distinguish between normal and malignant cells. The discovery of oncogenes and tumor suppressor genes involved in the process of transformation of normal cells into malignant cells has opened new areas of research in oncology, aimed at discovering drugs that could selectively inhibit their biological effects. This therapeutic modality, called an antisense strategy, has become a powerful tool for selectively reducing the expression of target genes in vitro, and there is increasing interest in the possibility of using the same technology in vivo for therapeutic purposes. In oncohematology, a number of trials have been initiated with antisense oligonucleotides directed against molecular targets, including the bcl-2, c-myc, bcr-abl, c-myb or p53 oncogenes and tumor suppressor genes. The experience gained from these studies will be applicable to the next generation of antisense compounds, which may include oligonucleotides with novel backbones or other structural modifications, as well as for expansion of the use of antisense oligonucleotides in combination approaches for the treatment of hematological malignancies.

Modulation of costimulatory molecules on follicular lymphoma cells by TNF and CD40.

TNF has recently been implicated in the formation of germinal center cells in lymphoid organs. Follicular lymphoma (FL) is thought to represent the pathological counterpart of germinal center B-cell. High levels of TNF and its soluble receptors were found in the plasma of FL patients whereas the transcripts of these molecules were previously found to be present in FL patients lymph nodes. We therefore studied here the effects of TNF on the expression of costimulatory molecules implicated in the cytotoxic T cell response on purified FL cells. In contrast to results described with B-type chronic lymphocytic leukemia, also characterized by high levels of circulating TNF, none of the tested samples showed a regulation of CD80, CD86, CD27 and CD70 in response to TNF. To confirm that the lack of regulation of these molecules was not due to the FL cells inability to modulate their expression, we therefore analyzed costimulatory molecules expression after CD40 pathway stimulation. After culture with human CD40L-transfected L-cells, an up-regulation of CD80, CD86 and CD70 expression was observed, while TNF addition in this model did not influence these changes. In this context, the CD27 molecule was down-regulated except in a single case, where its expression was increased. Taken together, this data demonstrates that in vitro expression of costimulatory molecules such as CD80, CD86, CD27 and CD70, which are implicated in the anti-tumoral response, can be regulated by CD40 ligand but not by TNF.

CD40 regulation of death domains containing receptors and their ligands on lymphoma B cells.

Within the tumour necrosis factor (TNF) family the induction of apoptosis is restricted to some ligand-receptors pairs, including TNF-TNF receptor type I (TNFRI/p55), FasL-Fas, TNF-related apoptosis-inducing ligand (TRAIL) and its death-receptors (DR)-4 and -5. The pair CD40L-CD40 belongs to the same family but rescues B cells from apoptosis. To investigate how these opposing actions are cross-linked, purified follicular lymphoma (FL) cells were activated upon a human CD40L-transfected murine fibroblastic layer, then RNA messengers for the above molecules were analysed using RT-PCR. The observed down-modulation of TRAIL and up-regulation of TNF and Fas transcripts might account for CD40-CD40L-mediated FL cell survival.

Plasma levels of tumour necrosis factor and its soluble receptors correlate with clinical features and outcome of Hodgkin's disease patients.

A prospective study was performed to assess the use of plasma measurement of tumour necrosis factor (TNF), lymphotoxin alpha (LT alpha) and their soluble receptors (p55 and p75) for prognostic risk assignment in 61 patients with Hodgkin's disease. Plasma levels of TNF, p55 and p75, but not of LT alpha, were higher in Hodgkin's disease patients than in healthy controls. Plasma levels of TNF, p55 and p75 were associated with several prognostic factors for Hodgkin's disease, including those related to the host (age, performance status) and to the tumour (disease stage, extranodal site involvement, bulky tumour, serum levels of LDH and beta2-microglobulin, histology). Elevated plasma levels of TNF, p55 and p75 were also associated with several parameters reflecting an immune activation, including the presence of B symptoms, elevated serum levels of gammaglobulins, alkaline phosphatase and fibrinogen, as well as peripheral monocytosis, anaemia and low serum albumin levels. Finally, elevated TNF ligand receptor plasma markers were associated with a lower incidence of complete response to therapy and predicted shorter free-from-progression survival and overall survival of the patients. These results indicate that the plasma levels of TNF and its soluble receptors correlate with clinical features and outcome of patients with Hodgkin's disease.

Genetic polymorphisms in the tumor necrosis factor locus influence non-Hodgkin's lymphoma outcome.

Systemic release of tumor necrosis factor (TNF) and lymphotoxin-alpha (LTalpha) has been found to contribute to the severity of non-Hodgkin's lymphoma (NHL). We investigated whether genetic polymorphisms in the TNF locus, previously shown to influence TNF and LTalpha genes expression, might contribute to these cytokines production and to the clinical course of NHL. Genomic DNA from 273 lymphoma patients was typed for TNF (-308) polymorphism using an allele-specific polymerase chain reaction (PCR) and for LTalpha (+252) polymorphism with a PCR-based restriction fragment length polymorphism. The presence of the TNF allele involved in increased TNF gene transcription was associated with higher plasma levels of this cytokine at the time of lymphoma diagnosis (chi2 test, P = .013). An extended haplotype analysis showed that the presence of at least two TNF or LTalpha high-producer alleles constituted a risk factor for first-line treatment failure (chi2 test, P = .021), shorter progression-free survival (log-rank test, P = .0007), and overall survival (log-rank test, P = .012). In the subgroup of 126 patients with diffuse large-cell lymphoma, the presence of two or more TNF/LTalpha high producing alleles contributed significantly to a higher rate of relapse and progression (log-rank test, P = .045 and P = .027). In multivariate Cox regression models including the variables of the International Prognostic Index, the TNF/LTalpha haplotype status was found to be an independent risk factor for progression-free survival (relative risk 2.33, 95% confidence interval [1.17 to 4.64], P = . 0053) and overall survival (relative risk 1.92, 95% confidence interval [0.63 to 5.80], P = .081) of large-cell lymphoma patients. These results indicate that genetic polymorphism leading to increased TNF production influences the outcome of NHL and suggest a pathophysiological role for the genetic control of the immune response in lymphoid malignancies.

The tumor necrosis factor signaling complex: choosing a path toward cell death or cell proliferation.

Signal transduction pathways which are initiated by the tumor necrosis factor (TNF) utilize receptors which are devoid of intrinsic catalytic activity. Recently identified two families of proteins that directly associate with the cytoplasmic domains of the TNF receptor family members, have partially bridged a molecular gap within the TNF-induced signaling pathways. Clearly, there are numerous alternate routes that originate from the TNF ligand-receptor assembly and terminate on the diverse cellular responses, including proliferation, differentiation, or death. This review focuses on recent advances characterizing the TNF ligand-receptor signaling network, which allow to better understand its participation in a life-death balance within the target cell.

A new death receptor 3 isoform: expression in human lymphoid cell lines and non-Hodgkin's lymphomas.

Two isoforms encoding the full-length transmembrane death receptor 3 (DR3) were isolated from mRNAs of a panel of human cell lines and tumor tissues obtained from patients with follicular non-Hodgkin's lymphoma. A new DR3 variant (DR3 beta) was characterized by 2 insertions of respectively 20- and 7-base pairs (bp) which result in a predictive translated polypeptide differing from the described DR3 molecule by a 28 amino-acid stretch in the extracellular domain. DR3 was shown to be expressed in all cell lines and lymphoma samples tested, whereas DR3 beta expression was restricted to lymphoid T-cell and immature B-cell lines and to selected cases with follicular lymphoma. These data provide new insight into the molecular heterogeneity of DR3, suggesting the presence of several receptor isoforms that can participate in lymphoid cell homeostasis.

Identification of two lymphotoxin beta isoforms expressed in human lymphoid cell lines and non-Hodgkin's lymphomas.

Two isoforms of lymphotoxin beta (LTbeta) were isolated from mRNAs of a panel of human lymphoid cell lines and tumor tissues obtained from patients with non-Hodgkin's lymphoma (NHL). The truncated LTbeta mRNA variant lacked 46 base pairs complementary to the complete sequence of exon 2, suggesting that both isoforms are produced by an alternative splicing mechanism. Skipping out of exon 2 causes a reading frame shift and a premature stop codon in the LTbeta mRNA variant. The predictive translated polypeptide would correspond to a severely shortened LTbeta protein that would lack the majority of the extracellular domain of the native molecule, thus impairing its normal complex assembly with LTalpha. These observations provide new insights into the molecular heterogeneity and biological function of LTbeta within the tumor necrosis factor and LT ligand-receptor system.

Prognostic significance of TNF alpha and its p55 soluble receptor in malignant lymphomas.

In 93 newly diagnosed lymphoma patients, tumor necrosis factor alpha (TNF alpha) and its p55 soluble receptor (p55-sR), were prospectively determined in plasma by IRMA and ELISA methods respectively. These 93 patients included 31 patients with low grade lymphoma, 55 with intermediate or high grade lymphoma and 7 with Hodgkin's disease. Median TNF alpha plasma values were 20 pg/mL (range 5-380 pg/mL) in patients versus 7 pg/mL (range 4-9 pg/mL) in healthy control subjects. Presence of TNF alpha level equal or greater than 20 pg/mL was significantly associated with elevated LDH level, serum beta 2-microglobulin level > or = 3 mg/L, hemoglobin < or = 12 g/dL, Ann Arbor stage III or IV disease, and with bulky tumor. High level of TNF alpha was also associated, although less strongly, with B symptoms, poor performance status, and serum albumin < or = 35 g/L, yet it was not associated with change in acute phase protein levels. Levels of p55-sR were also markedly elevated in these lymphoma patients (median of 3.5 ng/mL, range 0.8-18.8 ng/mL) versus 1.45 ng/mL in control subjects (range 1.1-2.3 ng/mL). Level of p55-sR equal or greater than 3.5 ng/mL was significantly associated with poor performance status, B symptoms, beta 2-microglobulin levels > or = 3 mg/L, serum albumin < or = 35 g/L, C-reactive protein > 6 mg/L, hemoglobin < or = 12 g/dL, and bulky tumor. In the whole group of 93 patients, both high TNF alpha and p55-sR levels strongly predicted short freedom from progression and overall survival. This study suggests that elevated TNF alpha and p55-sR plasma levels have a high correlation with other adverse prognostic factors in lymphoma patients and predict their poor outcome.