Sirpa Leppä

A High Tumor-Associated Macrophage Content Predicts Favorable Outcome in Follicular Lymphoma Patients Treated with Rituximab and Cyclophosphamide-Doxorubicin-Vincristine-Prednisone

Purpose: Tumor-associated macrophage (TAM) content predicts survival in follicular lymphoma (FL) patients treated with chemotherapy. The aim of this study was to determine how combination of rituximab with chemotherapy influences TAM-associated clinical outcome. Experimental Design: Expression of a macrophage marker, CD68, was determined immunohistochemically from FL samples of 96 patients treated with rituximab and cyclophosphamide-Adriamycin-vincristine-prednisone regimen. Of them, 71 received therapy at diagnosis and 25 at relapse. Neutrophil and CD3+ lymphocyte counts were also measured. The median follow-up time for the cohort was 54 months. Fourty-five patients previously treated with chemotherapy served as a control group. Results: Consistent with previous studies, high TAM amount was associated with adverse outcome in chemotherapy-treated patients (P = 0.026). In contrast, after rituximab and cyclophosphamide-doxorubicin-vincristine-prednisone regimen, high TAM content correlated with longer survival rates. According to Kaplan Meier estimates, the median progression free survival (PFS) was not reached for patients with high TAM content compared with 45 months for patients with low TAM scores (P = 0.006). A trend toward a better overall survival (OS) at 5 years was also observed for patients with high TAM content (OS, 97% versus 90%, P = 0.116). The positive prognostic value of TAMs was seen both for the patients treated at diagnosis and at relapse. In multivariate analyses, TAM content remained an independent prognostic factor for OS and PFS. Neutrophil and CD3+ lymphocyte counts did not correlate with outcome. Conclusions: The data suggest that high TAM score is associated with a favorable prognosis in FL patients treated with immunochemotherapy.

Activating mutations of STAT5B and STAT3 in lymphomas derived from γδ-T or NK cells

Lymphomas arising from NK or γδ-T cells are very aggressive diseases and little is known regarding their pathogenesis. Here we report frequent activating mutations of STAT3 and STAT5B in NK/T-cell lymphomas (n=51), γδ-T-cell lymphomas (n=43) and their cell lines (n=9) through next generation and/or Sanger sequencing. STAT5B N642H is particularly frequent in all forms of γδ-T-cell lymphomas. STAT3 and STAT5B mutations are associated with increased phosphorylated protein and a growth advantage to transduced cell lines or normal NK cells. Growth-promoting activity of the mutants can be partially inhibited by a JAK1/2 inhibitor. Molecular modelling and surface plasmon resonance measurements of the N642H mutant indicate a marked increase in binding affinity of the phosphotyrosine-Y699 with the mutant histidine. This is associated with the prolonged persistence of the mutant phosphoSTAT5B and marked increase of binding to target sites. Our findings suggest that JAK-STAT pathway inhibition may represent a therapeutic strategy.

EGF-R regulates MMP function in fibroblasts through MAPK and AP-1 pathways

EGF‐R regulates cell proliferation, migration, and invasion in fibroblasts. However, the connection of EGF‐R with downstream signaling pathways mediating these responses has remained elusive. Here we provide genetic and biochemical evidence that EGF‐R‐ and AP‐1‐mediated signals are required for MMP expression and collagen contraction in fibroblasts. In EGF‐R (−/−) mouse embryonal fibroblasts, basal and inducible expression of several MMPs, including MMP‐2, ‐3, and ‐14 is impaired in comparison to wild‐type counterparts. The loss of MMP expression is associated with a suppression of EGF‐induced Erk and Jnk activities, and AP‐1 DNA‐binding and transactivation capacities. While inhibition of Jnk mainly prevents EGF‐induced phosphorylation of c‐Jun, inhibition of Erk pathway suppresses both the expression and phosphorylation of c‐Jun and c‐Fos proteins. Moreover, the expression of MMP‐3 and ‐14, and collagen contraction is partially prevented by Mek/Erk and Jnk inhibitors. However, Jnk inhibitor also suppresses cell growth independently of EGF‐R activity. The central role of AP‐1 as a mediator of EGF‐R signaling in fibroblasts is emphasized by the finding that expression of a dominant negative c‐Jun downregulates the expression of MMP‐3. Conversely, expression of a constitutively active Mek1 can induce MMP‐3 expression independently of upstream signals. The results indicate that ERK pathway and AP‐1 are downstream effectors of the EGF‐R‐mediated MMP‐3 expression and collagen contraction in fibroblasts. J. Cell. Physiol. 212: 489–497, 2007.

Heat Shock Response - Pathophysiological Implications

All organisms exposed to environmental stress conditions share a common molecular response characterized by a dramatic change in the pattern of gene expression followed by an elevated synthesis of heat shock or stress proteins. These proteins function as molecular chaperones to protect cells from environmental stress damage by binding to partially denatured proteins, dissociating protein aggregates, and regulating the correct folding and intracellular translocation of newly synthesized polypeptides. Accumulating evidence supports a role for heat shock proteins in a number of disease states of which inflammatory reactions and ischaema provide the best studied examples. The inducible heat shock response involves transcriptional gene activation mediated by specific regulatory proteins called heat shock transcription factors, which bind to the promoter of heat shock genes in a sequence-specific manner. However, the signalling pathways leading to the activation of these transcription factors need to be characterized in more detail to be able to understand the role, cause, or consequence, of heat shock proteins in human diseases. This review presents recent progress in unravelling the regulation of heat shock gene expression in cells subjected to heat or other forms of stress. By using inflammatory responses and myocardial ischaema as examples, the putative use of heat shock proteins are discussed as targets for future therapeutic applications.

Complex Functions of AP-1 Transcription Factors in Differentiation and Survival of PC12 Cells

ABSTRACT c-Jun activation by mitogen-activated protein kinases has been implicated in various cellular signal responses. We investigated how JNK and c-Jun contribute to neuronal differentiation, cell survival, and apoptosis. In differentiated PC12 cells, JNK signaling can induce apoptosis and c-Jun mediates this response. In contrast, we show that in PC12 cells that are not yet differentiated, the AP-1 family member ATF-2 and not c-Jun acts as an executor of apoptosis. In this context c-Jun expression protects against apoptosis and triggers neurite formation. Thus, c-Jun has opposite functions before and after neuronal differentiation. These findings suggest a model in which the balance between ATF-2 and Jun activity in PC12 cells governs the choice between differentiation towards a neuronal fate and an apoptotic program. Further analysis of c-Jun mutants showed that the differentiation response requires functional dimerization and DNA-binding domains and that it is stimulated by phosphorylation in the transactivation domain. In contrast, c-Jun mutants incompetent for DNA binding or dimerization and also mutants lacking JNK binding and phosphorylation sites that cannot elicit neuronal differentiation efficiently protect PC12 cells from apoptosis. Hence, the protective role of c-Jun appears to be mediated by an unconventional mechanism that is separable from its function as a classical AP-1 transcription factor.

A High Serum Matrix Metalloproteinase-2 Level Is Associated with an Adverse Prognosis in Node-Positive Breast Carcinoma

Purpose: The aim of this study was to determine whether serum matrix metalloproteinase (MMP) -2 and MMP-9 levels could predict overall and disease-free survival in primary node-positive breast cancer. Experimental Design: MMP-2 and MMP-9 levels were quantitatively measured in serum after surgery from 133 patients with primary node-positive breast cancer using enzyme-linked immunoassays. All of the patients received adjuvant therapy, postmenopausal endocrine treatment (tamoxifen or toremifen for 3 years) and premenopausal six cycles of CMF chemotherapy. The follow-up time for all of the patients was 5 years. Results: Overall survival (OS) and disease-free survival (DFS) rates were better among patients with low MMP-2 levels than in patients with high levels (OS, 91% versus 75%, P = 0.020; DFS, 82% versus 58%, P = 0.005). The appearance of bone and visceral metastases was also significantly lower in patients with low serum MMP-2 levels (bone metastases, 10% versus 23%, P = 0.050; visceral metastases, 12% versus 34%, P = 0.018). The prognostic value of MMP-2 levels was most pronounced among a subgroup of estrogen receptor-positive patients (OS, 96% versus 78%, P = 0.052; DFS, 85% versus 58%, P = 0.014), whereas no significant difference was found among estrogen receptor-negative patients (OS, 73% versus 69%, P = 0.25; DFS, 73% versus 63%, P = 0.32). In multivariate analysis, MMP-2 level together with nodal status (NS), progesterone receptor (PgR), and tumor size (T) remained independent predictors for DFS (NS, P = 0.002; PgR, P = 0.004; T, P = 0.023; MMP2, P = 0.039) and OS (NS, P = 0.0002; PgR, P = 0.004; T, P = 0.004; MMP2, P = 0.032). MMP-9 levels did not correlate with survival. Conclusions: The results suggest that serum postoperative MMP-2 level is a predictor of DFS and OS, and could help to stratify breast cancer patients with primary node-positive disease into low- and high-risk groups.

Prognostic impact of activated B-cell focused classification in diffuse large B-cell lymphoma patients treated with R-CHOP

Gene expression profiling studies initially enabled diffuse large B-cell lymphoma to be divided into germinal center and activated B-cell-like subtypes, which define high- and low-risk patient groups when treated with chemotherapy. Attempts to reproduce the prognostic classification immunohistochemically have, however, provided inconsistent results. The aim of this study was to determine whether modified immunohistochemical classification of cell of origin focusing on activated B-cell-like markers could be used to predict the outcome of immunochemotherapy-treated diffuse large B-cell lymphoma patients. The expression of CD10, Bcl-6, MUM1/IRF4, Bcl-2, and FOXP1 was determined immunohistochemically from 88 samples of diffuse large B-cell lymphoma patients treated uniformly with R-CHOP. When the modified classification using MUM1/IRF4 and FOXP1 positivities as activated B-cell-like markers was applied to distinguish the patients between the activated B-cell-like and other diffuse large B-cell lymphoma subtypes, a significantly worse outcome was seen for the patients with the activated B-cell-like phenotype (3-year failure-free survival 63 vs 82%, P=0.048, overall survival 69 vs 85%, P=0.110). Similarly, according to the Muris algorithm, the group 2 patients representing Bcl-2-positive post-germinal center patients showed an inferior outcome in comparison to the group 1 patients (failure-free survival 59 vs 81%, P=0.041, overall survival 67 vs 82%, P=0.159). In contrast, when the classification of the same cohort was performed according to the Hans algorithm, no significant difference in survival was observed between the germinal center and non-germinal center patients. In conclusion, the data suggest that both the modified activated B-cell-like and Muris classifications define the non-germinal center phenotype as an adverse risk factor in R-CHOP-treated diffuse large B-cell lymphoma patients.

Autologous stem cell transplantation in adult patients with peripheral T-cell lymphoma: a nation-wide survey

Summary:Limited experience is available on the feasibility and efficacy of high-dose therapy (HDT) supported by autologous stem cell transplantation (ASCT) in patients with peripheral T-cell lymphoma (PTCL). Therefore, a nation-wide survey was conducted in adult patients transplanted for PTCL in Finland during 1990–2001. After histopathology review, 37 patients were identified. The median age was 46 years (16–68) at the time of ASCT. Histology included PTCL not otherwise specified in 14 patients, anaplastic large cell lymphoma (ALCL) in 14 patients, and other in nine patients. Disease status at the time of ASCT was CR/PR1 in 18 patients; CR/PR2 in 14 patients, and other in five patients. HDT consisted of either BEAC (N=22) or BEAM (N=15), supported by blood stem cells in 34 patients (92%). Early transplant-related mortality was 11%. With a median follow-up of 24 months from HDT, 16 patients (43%) have relapsed or progressed. The estimated 5-year overall survival (OS) was 54%. Patients with ALCL had superior OS when compared with other subtypes (85 vs 35%, P=0.007). OS at 5 years was 63% in patients transplanted in CR/PR1 vs 45% in those transplanted in other disease status (P=NS). Prospective studies are needed to define the role of ASCT in this lymphoma type.

Dose-densified chemoimmunotherapy followed by systemic central nervous system prophylaxis for younger high-risk diffuse large B-cell/follicular grade 3 lymphoma patients : results of a phase II Nordic Lymphoma Group study

BACKGROUND Many patients with aggressive B-cell lymphomas and high clinical risk score still die of lymphoma after conventional R-CHOP chemoimmunotherapy. We hypothesized that intensified chemoimmunotherapy including systemic central nervous system (CNS) prophylaxis improves outcome and reduces the incidence of CNS-related events. PATIENTS AND METHODS Inclusion criteria were age 18-65 years, primary diffuse large B-cell lymphoma or grade III follicular lymphoma without clinical signs of CNS disease and negative cerebrospinal fluid cytology, age-adjusted International Prognostic Index 2-3 and WHO performance score 0-3. Treatment consisted of six courses of R-CHOEP-14 followed by a course of high-dose cytarabine and a course of high-dose methotrexate. Primary end point was failure-free survival (FFS) at 3 years. RESULTS A total of 156 eligible patients with a median age of 54 years (range 20-64) were included. Three toxic deaths were observed. Three-year overall survival (OS) and FFS rates (median observation time 52 months for survivors) were 81% and 65%, respectively. Seven patients experienced CNS relapse, all within 6 months. CONCLUSIONS The results are promising with favorable 3-year OS and FFS rates, a low toxic death rate and a lower than expected number of CNS events. CNS progression might be further reduced by earlier CNS prophylaxis. CinicalTrials.gov. identifier NCT01502982.

Invasive fungal infections in autologous stem cell transplant recipients: a nation-wide study of 1188 transplanted patients

Abstract:  Based on small single‐centre series, the risk of invasive fungal infections (IFI) has been considered small in autologous stem cell transplant (ASCT) recipients. Purpose: To analyse epidemiological and clinical features of (IFI) among ASCT recipients in Finland 1990–2001. Patients: During the study period, 1188 adult patients received high‐dose therapy supported by ASCT in six centres. Altogether, 1112 patients (94%) received blood progenitor cells. The graft was CD34+ selected in 261 patients (22%). The major diagnostic groups were non‐Hodgkins lymphoma (n = 417), multiple myeloma (n = 395), breast cancer (n = 132) and Hodgkins lymphoma (n = 53). Results: Eighteen patients (1.5%) with IFI were identified. The incidence of proven or probable invasive aspergillosis was 0.8%, followed by candidaemia with an incidence of 0.3%. The median time to the diagnosis of IFI was 35 d (6–162) from the progenitor cell infusion. In fourteen patients (78%) IFI was diagnosed during lifetime and they were treated with antifungal therapy for a median of 50 d. Nine patients (64%) were cured. Conclusions: IFI appears to be a rare event after ASCT and Aspergillus infections seem to be predominant. These epidemiological features have an impact in planning prophylactic and empirical antifungal strategies in ASCT recipients.