ABL tyrosine kinase inhibitors (TKI) like Imatinib, Dasatinib and Nilotinib are the gold standard in conventional treatment of CML. However, the emergence of resistance remains a major problem. Alternative therapeutic strategies of ABL TKI-resistant CML are urgently needed. We asked whether dual inhibition of BCR-ABL and Aurora kinases A-C could overcome resistance mediated by ABL kinase mutations. We therefore tested the dual ABL and Aurora kinase inhibitors PHA-739358 and R763/AS703569 in Ba/F3- cells ectopically expressing wild type (wt) or TKI-resistant BCR-ABL mutants. We show that both compounds exhibited strong anti-proliferative and pro-apoptotic activity in ABL TKI resistant cell lines including cells expressing the strongly resistant T315I mutation. Cell cycle analysis indicated polyploidisation, a consequence of continued cell cycle progression in the absence of cell division by Aurora kinase inhibition. Experiments using drug resistant variants of Aurora B indicated that PHA-739358 acts on both, BCR-ABL and Aurora Kinase B, whereas Aurora kinase B inhibition might be sufficient for the anti-proliferative activity observed with R763/AS703569. Taken together, our data demonstrate that dual ABL and Aurora kinase inhibition might be used to overcome ABL TKI resistant CML.
Mucormycosis is an invasive mycotic disease caused by fungi in the zygomycetes class. Although ubiquitous in the environment, zygomycetes are rarely known to cause invasive disease in immunocompromised hosts with a high mortality even under aggressive antifungal and surgical therapy. Clinically, mucormycosis frequently affects the sinus occasionally showing pulmonary or cerebral involvement. However skeletal manifestation with Rhizopus microsporus (RM) osteomyelitis leading to emergency surgical proximal femoral resection with fatal outcome has not been described yet.
We report the case of a 73-year-old male suffering from myelodysplastic syndrome with precedent bone marrow transplantation. Six months after transplantation he consulted our internal medicine department in a septic condition with a four week history of painful swelling of the right hip. Radiography, computed tomography and magnetic resonance imaging revealed multiple bone infarcts in both femurs. In the right femoral head, neck and trochanteric region a recent infarct showed massive secondary osteomyelitis, breaking through the medial cortex. Emergency surgical proximal femoral resection was performed due to extensive bone and soft tissue destruction. Microbiological and basic local alignment search tool (BLAST) analysis revealed RM. Amphotericin B and posaconazole treatment with septic revision surgery was performed. However the disease ran a rapid course and was fatal two months after hospital admission.
This alarming result with extensive RM osteomyelitis in the proximal femur of an immunocompromised patient may hopefully warn medical staff to perform early imaging and aggressive surgical supported multimodal treatment in similar cases.
Mucormycosis; Rhizopus microsporus; Fungal osteomyelitis; Immunocompromitation; Radical surgical proximal femoral resection
Despite progress in the treatment of pancreatic cancer, there is still a need for improved therapies. In this manuscript, we report clinical experience with a new therapy for the treatment of pancreatic cancer involving the implantation of encapsulated cells over-expressing a cytochrome P450 enzyme followed by subsequent low-dose ifosfamide administrations as a means to target activated ifosfamide to the tumor. The safety and efficacy of the angiographic instillation of encapsulated allogeneic cells overexpressing cytochrome P450 in combination with low-dose systemic ifosfamide administration has now been evaluated in 27 patients in total. These patients were successfully treated in four centers by three different interventional radiologists, arguing strongly that the treatment can be successfully used in different centers. The safety of the intra-arterial delivery of the capsules and the lack of evidence that the patients developed an inflammatory or immune response to the encapsulated cells or encapsulation material was shown in all 27 patients. The ifosfamide dose of 1 g/m2/day used in the first trial was well tolerated by all patients. In contrast, the ifosfamide dose of 2 g/m2/day used in the second trial was poorly tolerated in most patients. Since the median survival in the first trial was 40 weeks and only 33 weeks in the second trial, this strongly suggests that there is no survival benefit to increasing the dose of ifosfamide, and indeed, a lower dose is beneficial for quality of life and the lack of side effects. This is supported by the one-year survival rate in the first trial being 38%, whilst that in the second trial was only 23%. However, taking the data from both trials together, a total of nine of the 27 patients were alive after one year, and two of these nine patients were alive for two years or more.
pancreatic cancer; cytochrome P450; cell therapy; encapsulation; ifosfamide; safety; efficacy; bioencapsulation; targeting chemotherapy; low dose; quality of life
Anaplastic large cell lymphoma (ALCL) is a common subtype of the heterogeneous group of peripheral T-cell lymphomas, which is characterized by large pleomorphic cells with strong expression of CD30. Translocations involving ALK, the anaplastic lymphoma kinase gene, are associated with a favorable clinical outcome. Such ALK-positive ALCLs are usually responsive to a multidrug chemotherapy with CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone). However, there is no general consensus on the optimal therapy for relapsed or refractory ALCL. We report the case of a 24-year-old male suffering from ALK-positive ALCL with an uncommon manifestation of only extranodal disease in the gastric cardia region that showed primary refractoriness to standard CHOP chemotherapy. A combination therapy consisting of the anti-CD30 drug conjugate, brentuximab vedotin, and classical lymphoma salvage regimen DHAP (cisplatin, high-dose cytarabine and dexamethasone) was administered. Following two treatment cycles in 21-day intervals, the lymphoma showed considerable regression based on imaging diagnostics and no evidence of vital lymphoma in a subsequent biopsy. We did not observe any increase in toxicity; in particular, polyneuropathy and febrile neutropenia were not observed. In summary, we report that the antibody-drug conjugate brentuximab vedotin and a classical regimen used for aggressive lymphoma, DHAP, could be combined as salvage therapy in a case of refractory ALK-positive ALCL. Phase I/II studies will be required for safety and efficacy analysis.
anaplastic large cell lymphoma (ALCL); refractory relapsed lymphoma; anti-CD30 drug conjugate; DHAP; combined therapy
Despite improved survival in the Rituximab (R) era, a considerable number of patients with diffuse large B-cell lymphoma (DLBCL) ultimately die from the disease. Functional imaging using [18F]fluorodeoxyglucose-PET is suggested for assessment of residual viable tumor very early during treatment but is compromised by non-specific tracer retention in inflammatory lesions. The PET tracer [18F]fluorodeoxythymidine (FLT) as surrogate marker of tumor proliferation may overcome this limitation. We present results of a prospective clinical study testing FLT-PET as superior and early predictor of response to chemotherapy and outcome in DLBCL. 54 patients underwent FLT-PET prior to and one week after the start of R-CHOP chemotherapy. Repetitive FLT-PET imaging was readily implemented into the diagnostic work-up. Our data demonstrate that the reduction of FLT standard uptake valuemean (SUVmean) and SUVmax one week after chemotherapy was significantly higher in patients achieving complete response (CR, n=48; non-CR, n=6; p<0.006). Martingale-residual and Cox proportional hazard analyses showed a significant monotonous decrease of mortality risk with increasing change in SUV. Consistent with these results, early FLT-PET response showed relevant discriminative ability in predicting CR. In conclusion, very early FLT-PET in the course of R-CHOP chemotherapy is feasible and enables identification of patients at risk for treatment failure.
Lymphoma; DLBCL; Positron emission tomography; [18F]Fluorodeoxythymidine; FLT-PET
Dual phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycin (mTOR) inhibition offers an attractive therapeutic strategy in anaplastic large cell lymphoma depending on oncogenic nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) signaling. We tested the efficacy of a novel dual PI3K/mTOR inhibitor, NVP-BGT226 (BGT226), in two anaplastic large cell lymphoma cell lines in vitro and in vivo and performed an early response evaluation with positron emission tomography (PET) imaging using the standard tracer, 2-deoxy-2-[18F]fluoro-D-glucose (FDG) and the thymidine analog, 3′-deoxy-3′-[18F] fluorothymidine (FLT).
The biological effects of BGT226 were determined in vitro in the NPM-ALK positive cell lines SU-DHL-1 and Karpas299 by 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, propidium iodide staining, and biochemical analysis of PI3K and mTOR downstream signaling. FDG-PET and FLT-PET were performed in immunodeficient mice bearing either SU-DHL-1 or Karpas299 xenografts at baseline and 7 days after initiation of treatment with BGT226. Lymphomas were removed for immunohistochemical analysis of proliferation and apoptosis to correlate PET findings with in vivo treatment effects.
SU-DHL-1 cells showed sensitivity to BGT226 in vitro, with cell cycle arrest in G0/G1 phase and an IC50 in the low nanomolar range, in contrast with Karpas299 cells, which were mainly resistant to BGT226. In vivo, both FDG-PET and FLT-PET discriminated sensitive from resistant lymphoma, as indicated by a significant reduction of tumor-to-background ratios on day 7 in treated SU-DHL-1 lymphoma-bearing animals compared with the control group, but not in animals with Karpas299 xenografts. Imaging results correlated with a marked decrease in the proliferation marker Ki67, and a slight increase in the apoptotic marker, cleaved caspase 3, as revealed by immunostaining of explanted lymphoma tissue.
Dual PI3K/mTOR inhibition using BGT226 is effective in ALK-positive anaplastic large cell lymphoma and can be monitored with both FDG-PET and FLT-PET early on in the course of therapy.
lymphoma; phosphatidylinositol-3-kinase; mammalian target of rapamycin; inhibition; positron emission tomography
Conditioning therapies before transplantation induce the release of uric acid, which triggers the NLRP3 inflammasome and IL-1β production contributing to graft-versus-host disease.
The success of allogeneic hematopoietic cell transplantation is limited by acute graft-versus-host disease (GvHD), a severe complication accompanied by high mortality rates. Yet, the molecular mechanisms initiating this disease remain poorly defined. In this study, we show that, after conditioning therapy, intestinal commensal bacteria and the damage-associated molecular pattern uric acid contribute to Nlrp3 inflammasome–mediated IL-1β production and that gastrointestinal decontamination and uric acid depletion reduced GvHD severity. Early blockade of IL-1β or genetic deficiency of the IL-1 receptor in dendritic cells (DCs) and T cells improved survival. The Nlrp3 inflammasome components Nlrp3 and Asc, which are required for pro–IL-1β cleavage, were critical for the full manifestation of GvHD. In transplanted mice, IL-1β originated from multiple intestinal cell compartments and exerted its effects on DCs and T cells, the latter being preferentially skewed toward Th17. Compatible with these mouse data, increased levels of active caspase-1 and IL-1β were found in circulating leukocytes and intestinal GvHD lesions of patients. Thus, the identification of a crucial role for the Nlrp3 inflammasome sheds new light on the pathogenesis of GvHD and opens a potential new avenue for the targeted therapy of this severe complication.
Nijmegen Breakage Syndrome (NBS) is a rare autosomal recessive DNA repair disorder characterized by immune deficiency, microcephaly, mental retardation and a disposition for the development of hematological malignancies. So far, mostly pediatric patients have been described, since the underlying condition is often fatal before adulthood. Many patients diagnosed with Hodgkin lymphoma (HL) due to this DNA repair defect receive reduced treatment followed by early progression and fatal outcome.
We describe here a 26-year old male caucasian patient with NBS who presented with multi organ failure due to HL. Immediate intensive chemotherapy lead to complete remission and reversed organ failure.
We show that application of standard chemotherapy can lead to long-term disease free survival in patients with a DNA repair disorder. Furthermore, we describe here, to the best of our knowledge, the first adult patient with NBS and HL.
Nijmegen breakage syndrome; DNA repair disorder; Hodgkin lymphoma; ABVD chemotherapy
Members of the PRDM protein family have been shown to play important roles during embryonic development. Previous in vitro and in situ analyses indicated a function of Prdm6 in cells of the vascular system. To reveal physiological functions of Prdm6, we generated conditional Prdm6-deficient mice. Complete deletion of Prdm6 results in embryonic lethality due to cardiovascular defects associated with aberrations in vascular patterning. However, smooth muscle cells could be regularly differentiated from Prdm6-deficient embryonic stem cells and vascular smooth muscle cells were present and proliferated normally in Prdm6-deficient embryos. Conditional deletion of Prdm6 in the smooth muscle cell lineage using a SM22-Cre driver line resulted in perinatal lethality due to hemorrhage in the lungs. We thus identified Prdm6 as a factor that is essential for the physiological control of cardiovascular development.
Patients with B cell malignancies refractory to allogeneic stem cell transplantation (SCT) can be treated by subsequent immunotherapy with donor lymphocyte infusions (DLI). But unlike myeloid leukemia, B cell leukemia and lymphoma are less sensitive to allogeneic adoptive immunotherapy. Moreover, the beneficial graft-versus-lymphoma (GVL) effect may be associated with moderate to severe graft-versus-host disease (GVHD). Thus, novel therapeutic approaches augmenting the anti-tumor efficacy of DLI and dissociating the GVL effect from GVHD are needed. The anti-CD20 x anti-CD3 trifunctional bispecific antibody (trAb) FBTA05 may improve the targeting of tumor cells by redirecting immune allogeneic effector cells while reducing the risk of undesirable reactivity against normal host cells. Hence, FBTA05 may maximize GVL effects by simultaneously decreasing the incidence and severity of GVHD.
Based on this underlying treatment concept and on promising data taken from preclinical results and a small pilot study, an open-label, non-randomized, uncontrolled, dose-escalating phase I/II-study is conducted to evaluate safety and preliminary efficacy of the investigational antibody FBTA05 in combination with DLI for patients suffering from rituximab- and/or alemtuzumab-refractory, CD20-positive low- or high-grade lymphoma after allogeneic SCT. During the first trial phase with emphasis on dose escalation a maximum of 24 patients distributed into 4 cohorts will be enrolled. For the evaluation of preliminary efficacy data a maximum of 12 patients (6 patients with low-grade lymphoma and/or Chronic Lymphocytic Leukemia (CLL) / 6 patients with high-grade or aggressive lymphoma) will attend the second phase of this clinical trial.
Promising data (e.g. induction of cellular immunity; GVL predominance over GVHD; achievement of partial or complete responses; prolongation of time-to-progression) obtained from this phase I/II trial would represent the first milestone in the clinical evaluation of a novel immunotherapeutic concept for treatment-resistant low- and high-grade lymphoma and NHL patients in relapse.
B Cell Malignancies; Allogeneic Transplantation; Donor Lymphocyte Infusion; Immunotherapy; Trifunctional Bispecific Antibody (trAb)
Radioimmunotherapy (RIT) has been used to treat relapsed/refractory CD20+ Non-Hodgkin lymphoma (NHL). Myeloablative anti-CD20 RIT followed by autologous stem cell infusion (ASCT) enables high radiation doses to lymphoma sites. We performed a phase I/II trial to assess feasibility and survival.
Twenty-three patients with relapsed/refractory NHL without complete remission (CR) to salvage chemotherapy were enrolled to evaluate RIT with Iodine-131 labelled rituximab (131I-rituximab) in a myeloablative setting. Biodistribution and dosimetric studies were performed to determine 131I activity required to induce a total body dose of 21-27Gy to critical organs. In 6/23 patients RIT was combined with high-dose chemotherapy. 8/23 patients received a sequential high-dose chemotherapy with a second ASCT. The median follow-up is 9.5 years.
6.956-19.425GBq of 131I was delivered to achieve the limiting organ dose to lungs or kidneys. No grade III/IV non-hematologic toxicity was seen with RIT alone. Significant grade III/IV toxicity (mucositis, fever, infection, one therapy related death) was observed in patients treated with RIT combined with high-dose chemotherapy. The overall response rate was 87% (64% CR). The median progression-free (PFS) and overall survival (OS) is 47.5 and 101.5 months. An international prognostic index score >1 was predictive for OS.
Myeloablative RIT with 131I-rituximab followed by ASCT is feasible, well-tolerated and effective in high risk CD20+ NHL. Combination of RIT and high-dose chemotherapy increased toxicity significantly. Long-term results for PFS and OS are encouraging.
Non-Hodgkin lymphoma; Radioimmunotherapy; CD20; High-dose chemotherapy; Autologous stem cell transplantation
An improvement in overall survival among patients with metastatic melanoma has been an elusive goal. In this phase 3 study, ipilimumab — which blocks cytotoxic T-lymphocyte–associated antigen 4 to potentiate an antitumor T-cell response — administered with or without a glycoprotein 100 (gp100) peptide vaccine was compared with gp100 alone in patients with previously treated metastatic melanoma.
A total of 676 HLA-A⋆0201–positive patients with unresectable stage III or IV melanoma, whose disease had progressed while they were receiving therapy for metastatic disease, were randomly assigned, in a 3:1:1 ratio, to receive ipilimumab plus gp100 (403 patients), ipilimumab alone (137), or gp100 alone (136). Ipilimumab, at a dose of 3 mg per kilogram of body weight, was administered with or without gp100 every 3 weeks for up to four treatments (induction). Eligible patients could receive reinduction therapy. The primary end point was overall survival.
The median overall survival was 10.0 months among patients receiving ipilimumab plus gp100, as compared with 6.4 months among patients receiving gp100 alone (hazard ratio for death, 0.68; P<0.001). The median overall survival with ipilimumab alone was 10.1 months (hazard ratio for death in the comparison with gp100 alone, 0.66; P = 0.003). No difference in overall survival was detected between the ipilimumab groups (hazard ratio with ipilimumab plus gp100, 1.04; P = 0.76). Grade 3 or 4 immune-related adverse events occurred in 10 to 15% of patients treated with ipilimumab and in 3% treated with gp100 alone. There were 14 deaths related to the study drugs (2.1%), and 7 were associated with immune-related adverse events.
Ipilimumab, with or without a gp100 peptide vaccine, as compared with gp100 alone, improved overall survival in patients with previously treated metastatic melanoma. Adverse events can be severe, long-lasting, or both, but most are reversible with appropriate treatment. (Funded by Medarex and Bristol-Myers Squibb; ClinicalTrials.gov number, NCT00094653.)
Tumor cell survival critically depends on heterotypic communication with benign cells in the microenvironment. Here, we describe a survival signaling pathway activated in stromal cells by contact to B cells from patients with chronic lymphocytic leukemia (CLL). The expression of protein kinase C (PKC)-βII and the subsequent activation of NF-κB in bone marrow stromal cells are prerequisites to support the survival of malignant B cells. PKC-β knockout mice are insusceptible to CLL transplantations, underscoring the in vivo significance of the PKC-βII-NF-κB signaling pathway in the tumor microenvironment. Upregulated stromal PKC-βII in biopsies from patients with CLL, acute lymphoblastic leukemia, and mantle cell lymphoma suggests that this pathway may commonly be activated in a variety of hematological malignancies.
► Malignant B cells induce the expression of PKC-βII in bone marrow stromal cells ► The activation of NF-κB in tumor stromal cells strictly depends on PKC-βII ► The PKC-βII-NF-κB pathway is indispensable for survival of malignant B cells in vivo ► The PKC-βII-NF-κB pathway is activated by ALL and mantle cell lymphoma cells
Cks1 is an activator of the SCFSkp2 ubiquitin ligase complex that targets the cell cycle inhibitor p27Kip1 for degradation. The loss of Cks1 results in p27Kip1 accumulation and decreased proliferation and inhibits tumorigenesis. We identify here a function of Cks1 in mammalian cell cycle regulation that is independent of p27Kip1. Specifically, Cks1−/−; p27Kip1−/− mouse embryonic fibroblasts retain defects in the G1-S phase transition that are coupled with decreased Cdk2-associated kinase activity and defects in proliferation that are associated with Cks1 loss. Furthermore, concomitant loss of Cks1 does not rescue the tumor suppressor function of p27Kip1 that is manifest in various organs of p27Kip1−/− mice. In contrast, defects in mitotic entry and premature senescence manifest in Cks1−/− cells are p27Kip1 dependent. Collectively, these findings establish p27Kip1-independent functions of Cks1 in regulating the G1-S transition.
The Cks1 component of the SCFSkp2 complex is necessary for p27Kip1 ubiquitylation and degradation. Cks1 expression is elevated in various B cell malignancies including Burkitt lymphoma and multiple myeloma. We have previously shown that loss of Cks1 results in elevated p27Kip1 levels and delayed tumor development in a mouse model of Myc-induced B cell lymphoma. Surprisingly, loss of Skp2 in the same mouse model also resulted in elevated p27Kip1 levels but exhibited no impact on tumor onset. This raises the possibility that Cks1 could have other oncogenic activities than suppressing p27Kip1. To challenge this notion we have targeted overexpression of Cks1 to B cells using a conditional retroviral bone marrow transduction-transplantation system. Despite potent ectopic overexpression, Cks1 was unable to promote B cell hyperproliferation or B cell malignancies, indicating that Cks1 is not oncogenic when overexpressed in B cells. Since Skp2 overexpression can drive T-cell tumorigenesis or other cancers we also widened the quest for oncogenic activity of Cks1 by ubiquitously expressing Cks1 in hematopoetic progenitors. At variance with c-Myc overexpression, which caused acute myeloid leukemia, Cks1 overexpression did not induce myeloproliferation or leukemia. Therefore, despite being associated with a poor prognosis in various malignancies, sole Cks1 expression is insufficient to induce lymphoma or a myeloproliferative disease in vivo.
Induction high-dose chemotherapy followed by myeloablative melphalan (HD-Mel) treatment and autologous hematopoietic stem-cell support (autoSCT) is a standard treatment for multiple myeloma (MM) either upfront or in relapse after conventional treatment. We performed a retrospective analysis of consecutive patients undergoing a late repeat HD-Mel/autoSCT treatment for MM.
Data from 24 consecutive patients with MM who underwent a myeloablative treatment with HD-Mel late after completion of upfront first high-dose therapy were assessed for toxicity, response, progression-free survival (PFS) and time to next treatment (TTNT). These data were correlated with the results obtained after the initial high dose therapy and autoSCT.
A total of 23 patients were treated with novel drugs (lenalidomide, thalidomide, bortezomib) after relapse to initial autoSCT. The median overall survival (OS) of all patients was 90 months. 19 patients (79%) achieved a very good partial remission (VGPR) or complete remission (CR) after initial autoSCT, compared with 42% after late autoSCT. PFS and TTNT were 19 and 24 months after initial compared with 13 and 21 months after late autoSCT. Univariate analysis identified initial response duration and the achievement of a CR/VGPR after the initial transplantation to be associated with prolonged response after repeat autoSCT.
Our data indicate that late high-dose treatment followed by autoSCT is safe and effective after upfront intensive treatment, can bridge to allogeneic SCT, and encourage collection of an additional graft.
high-dose therapy; multiple myeloma; stem-cell transplantation
NIPA (Nuclear Interaction Partner of Alk kinase) is an F-box like protein
that targets nuclear Cyclin B1 for degradation. Integrity and therefore activity
of the SCFNIPA E3 ligase is regulated by cell-cycle-dependent phosphorylation
of NIPA, restricting substrate ubiquitination to interphase. Here we show
that phosphorylated NIPA is degraded in late mitosis in an APC/CCdh1-dependent
manner. Binding of the unphosphorylated form of NIPA to Skp1 interferes with
binding to the APC/C-adaptor protein Cdh1 and therefore protects unphosphorylated
NIPA from degradation in interphase. Our data thus define a novel mode of
regulating APC/C-mediated ubiquitination.
The activity of the epidermal growth factor receptor (EGFR)-directed monoclonal antibody cetuximab combined with oxaliplatin/leucovorin/5-fluorouracil (FUFOX) was assessed in first-line metastatic gastric and oesophago-gastric junction (OGJ) cancer in a prospective phase II study showing a promising objective tumour response rate of 65% and a low mutation frequency of KRAS (3%). The aim of the correlative tumour tissue studies was to investigate the relationship between EGFR gene copy numbers, activation of the EGFR pathway, expression and mutation of E-cadherin, V600E BRAF mutation and clinical outcome of patients with gastric and OGJ cancer treated with cetuximab combined with FUFOX.
Patients included in this correlative study (n = 39) were a subset of patients from the clinical phase II study. The association between EGFR gene copy number, activation of the EGFR pathway, abundance and mutation of E-cadherin which plays an important role in these disorders, BRAF mutation and clinical outcome of patients was studied. EGFR gene copy number was assessed by FISH. Expression of the phosphorylated forms of EGFR and its downstream effectors Akt and MAPK, in addition to E-cadherin was analysed by immunohistochemistry. The frequency of mutant V600E BRAF was evaluated by allele-specific PCR and the mutation profile of the E-cadherin gene CDH1 was examined by DHPLC followed by direct sequence analysis. Correlations with overall survival (OS), time to progression (TTP) and overall response rate (ORR) were assessed.
Our study showed a significant association between increased EGFR gene copy number (≥ 4.0) and OS in gastric and OGJ cancer, indicating the possibility that patients may be selected for treatment on a genetic basis. Furthermore, a significant correlation was shown between activated EGFR and shorter TTP and ORR, but not between activated EGFR and OS. No V600E BRAF mutations were identified. On the other hand, an interesting trend between high E-cadherin expression levels and better OS was observed and two CDH1 exon 9 missense mutations (A408V and D402H) were detected.
Our finding that increased EGFR gene copy numbers, activated EGFR and the E-cadherin status are potentially interesting biomarkers needs to be confirmed in larger randomized clinical trials.
Multicentre clinical study with the European Clinical Trials Database number 2004-004024-12.
Overexpression of the ERBB2 kinase is observed in about one-third of breast cancer patients and the dual ERBB1/ERBB2 kinase inhibitor lapatinib was recently approved for the treatment of advanced ERBB2-positive breast cancer. Mutations in the ERBB2 receptor have recently been reported in breast cancer at diagnosis and also in gastric, colorectal and lung cancer. These mutations may have an impact on the clinical responses achieved with lapatinib in breast cancer and may also have a potential impact on the use of lapatinib in other solid cancers. However, the sensitivity of lapatinib towards clinically observed ERBB2 mutations is not known.
We cloned a panel of 8 clinically observed ERBB2 mutations, established stable cell lines and characterized their sensitivity towards lapatinib and alternative ERBB2 inhibitors. Both lapatinib-sensitive and lapatinib-resistant ERBB2 mutations were observed. Interestingly, we were able to generate lapatinib resistance mutations in wt-ERBB2 cells incubated with lapatinib for prolonged periods of time. This indicates that these resistance mutations may also cause secondary resistance in lapatinib-treated patients. Lapatinib-resistant ERBB2 mutations were found to be highly resistant towards AEE788 treatment but remained sensitive towards the dual irreversible inhibitors CL-387785 and WZ-4002.
Patients harbouring certain ERBB2 kinase domain mutations at diagnosis may not benefit from lapatinib treatment. Moreover, secondary lapatinib resistance may develop due to kinase domain mutations. Irreversible ERBB2 inhibitors may offer alternative treatment options for breast cancer and other solid tumor patients harbouring lapatinib resistance mutations. In addition, these inhibitors may be of interest in the scenario of secondary lapatinib resistance.
Squamous cell cancer of the head and neck (SCCHN) is the sixth leading cause for cancer deaths worldwide. Despite extense knowledge of risk factors and pathogenesis about 50 percent of all patients and essentially every patient with metastatic SCCHN eventually die from this disease. We analyzed the clinical data and performed immunohistochemistry for Epidermal growth factor receptor (EGFR) and Aurora kinase A (Aurora-A) expression in 180 SCCHN patients. Patients characterized by elevated EGFR and elevated Aurora-A protein expression in tumor tissue represent a risk group with poor disease-free and overall survival (EGFRlow Aurora-Alow versus EGFRhigh Aurora-Ahigh, p = 0.024). Treating SCCHN cell lines with a pan-Aurora kinase inhibitor resulted in defective cytokinesis, polyploidy and apoptosis, which was effective irrespective of the EGFR status. Combined Aurora kinase and EGFR targeting using a monoclonal anti-EGFR antibody was more effective compared to single EGFR and Aurora kinase inhibition. Comparing pan-Aurora kinase and Aurora-A targeting hints towards a strong and clinically relevant biological effect mediated via Aurora kinase B. Taken together, our findings characterize a new poor risk group in SCCHN patients defined by elevated EGFR and Aurora-A protein expression. Our results demonstrate that combined targeting of EGFR and Aurora kinases represents a therapeutic means to activate cell cycle checkpoints and apoptosis in SCCHN.
Squamous cell cancer of the head and neck; Aurora kinase; EGFR
The universal cyclin-Cdk inhibitor p27Kip1 functions as a tumor suppressor and reduced levels of p27Kip1 connote poor prognosis in several human malignancies. p27Kip1 levels are predominately regulated by ubiquitin-mediated turnover of the protein, which is marked for destruction by the E3 ubiquitin ligase SCFSkp2 complex following its phosphorylation by the cyclin E-Cdk2 complex. Binding of phospho-p27Kip1 is directed by the Skp2 F-box protein, and this is greatly augmented by its allosteric regulator Cks1. We have established that programmed expression of c-Myc in the B cells of Eμ-Myc transgenic mice triggers p27Kip1 destruction by inducing Cks1, that this response controls Myc-driven proliferation, and that loss of Cks1 markedly delays Myc-induced lymphomagenesis and cancels the dissemination of these tumors. Here, we report that elevated levels of Skp2 are a characteristic of Eμ-Myc lymphomas and of human Burkitt lymphoma that bear MYC/immunoglobulin chromosomal translocations. As expected, Myc-mediated suppression of p27Kip1 was abolished in Skp2-null Eμ-Myc B cells. However, the impact of Skp2 loss on Myc-driven proliferation and lymphomagenesis was surprisingly modest compared to the effects of Cks1 loss. Collectively these findings suggest that Cks1 targets in addition to p27Kip1 are critical for Myc-driven proliferation and tumorigenesis.
Myc; Skp2; p27Kip1; lymphomagenesis
Peripheral T cell lymphomas (PTCLs) are highly aggressive malignancies with poor prognosis. Their molecular pathogenesis is not well understood and small animal models for the disease are lacking. Recently, the chromosomal translocation t(5;9)(q33;q22) generating the interleukin-2 (IL-2)–inducible T cell kinase (ITK)–spleen tyrosine kinase (SYK) fusion tyrosine kinase was identified as a recurrent event in PTCL. We show that ITK-SYK associates constitutively with lipid rafts in T cells and triggers antigen-independent phosphorylation of T cell receptor (TCR)–proximal proteins. These events lead to activation of downstream pathways and acute cellular outcomes that correspond to regular TCR ligation, including up-regulation of CD69 or production of IL-2 in vitro or deletion of thymocytes and activation of peripheral T cells in vivo. Ultimately, conditional expression of patient-derived ITK-SYK in mice induces highly malignant PTCLs with 100% penetrance that resemble the human disease. Our work demonstrates that constitutively enforced antigen receptor signaling can, in principle, act as a powerful oncogenic driver. Moreover, we establish a robust clinically relevant and genetically tractable model of human PTCL.
Deregulated c-Myc expression is a hallmark of several human cancers where it promotes proliferation and an aggressive tumour phenotype. Myc overexpression is associated with reduced activity of Rel/NF-κB, transcription factors that control the immune response, cell survival, and transformation, and that are frequently altered in cancer. The Rel/NF-κB family member NFKB2 is altered by chromosomal translocations or deletions in lymphoid malignancies and deletion of the C-terminal ankyrin domain of NF-κB2 augments lymphocyte proliferation.
Precancerous Eμ-Myc-transgenic B cells, Eμ-Myc lymphomas and human Burkitt lymphoma samples were assessed for Nfkb2 expression. The contribution of Nfkb2 to Myc-driven apoptosis, proliferation, and lymphomagenesis was tested genetically in vivo.
Here we report that the Myc oncoprotein suppresses Nfkb2 expression in vitro in primary mouse fibroblasts and B cells, and in vivo in the Eμ-Myc transgenic mouse model of human Burkitt lymphoma (BL). NFKB2 suppression by Myc was also confirmed in primary human BL. Promoter-reporter assays indicate that Myc-mediated suppression of Nfkb2 occurs at the level of transcription. The contribution of Nfkb2 to Myc-driven lymphomagenesis was tested in vivo, where Nfkb2 loss was shown to accelerate lymphoma development in Eμ-Myc transgenic mice, by impairing Myc's apoptotic response.
Nfkb2 is suppressed by c-Myc and harnesses Myc-driven lymphomagenesis. These data thus link Myc-driven lymphomagenesis to the non-canonical NF-κB pathway.
Diffuse large B cell lymphoma (DLBCL) is the most common type of lymphoma in humans. The aggressive activated B cell–like (ABC) subtype of DLBCL is characterized by constitutive NF-κB activity and requires signals from CARD11, BCL10, and the paracaspase MALT1 for survival. CARD11, BCL10, and MALT1 are scaffold proteins that normally associate upon antigen receptor ligation. Signal-induced CARD11–BCL10–MALT1 (CBM) complexes couple upstream events to IκB kinase (IKK)/NF-κB activation. MALT1 also possesses a recently recognized proteolytic activity that cleaves and inactivates the negative NF-κB regulator A20 and BCL10 upon antigen receptor ligation. Yet, the relevance of MALT1 proteolytic activity for malignant cell growth is unknown. Here, we demonstrate preassembled CBM complexes and constitutive proteolysis of the two known MALT1 substrates in ABC-DLBCL, but not in germinal center B cell–like (GCB) DLBCL. ABC-DLBCL cell treatment with a MALT1 protease inhibitor blocks A20 and BCL10 cleavage, reduces NF-κB activity, and decreases the expression of NF-κB targets genes. Finally, MALT1 paracaspase inhibition results in death and growth retardation selectively in ABC-DLBCL cells. Thus, our results indicate a growth-promoting role for MALT1 paracaspase activity in ABC-DLBCL and suggest that a pharmacological MALT1 protease inhibition could be a promising approach for lymphoma treatment.