The dendroanalysis of oak trees as a method of biomonitoring past and recent contamination in an area influenced by uranium mining

We reconstructed the contamination history of an area influenced by 40 years of uranium mining and subsequent remediation actions using dendroanalysis (i.e., the determination of the elemental content of tree rings). The uranium content in the tree rings of four individual oak trees (Quercus sp.) was determined by laser ablation with inductively coupled plasma mass spectrometry (LA-ICP-MS). This technique allows the investigation of trace metals in solid samples with a spatial resolution of 250 μm and a detection limit below 0.01 μg/g for uranium. The investigations show that in three of the four oaks sampled, there were temporally similar uranium concentrations. These were approximately 2 orders of magnitude higher (0.15 to 0.4 μg/g) than those from before the period of active mining (concentrations below 0.01 μg/g). After the mining was terminated and the area was restored, the uranium contents in the wood decreased by approximately 1 order of magnitude. The similar radial uranium distribution patterns of the three trees were confirmed by correlation analysis. In combination with the results of soil analyses, it was determined that there was a heterogeneous contamination in the forest investigated. This could be confirmed by pre-remediation soil uranium contents from literature. The uranium contents in the tree rings of the oaks investigated reflect the contamination history of the study area. This study demonstrates that the dendrochemical analysis of oak tree rings is a suitable technique for investigating past and recent uranium contamination in mining areas.

Multicenter phase II trial to investigate safety and efficacy of gemcitabine combined with cetuximab as adjuvant therapy in pancreatic cancer (ATIP)

BACKGROUND

To investigate whether addition of cetuximab to standard adjuvant chemotherapy with gemcitabine improves outcome in pancreatic cancer, specifically whether the rate of disease-free survival (DFS) at 18 months (primary end point) exceeds the previously reported 35% of gemcitabine alone.

PATIENTS AND METHODS

Prospective, open-label, multicenter, nonrandomized phase II study in 76 patients with R0- or R1-resected ductal adenocarcinoma of the pancreas included between October 2006 and November 2008. Gemcitabine and cetuximab were administered for 24 weeks. Secondary end points included overall survival (OS) and toxic effect.

RESULTS

Seventy-three patients received cetuximab. Median DFS was 10.0 [95% confidence interval (CI) 8.9-13.6] months and the DFS rate at month 18 of 27.1% (16.7%-37.6%) was inferior to 35%. Median OS was 22.4 (18.2-27.9) months. Subgroup analyses revealed a nonsignificant increase in DFS for patients with versus without skin toxic effect ≥ grade 2 (median 14.7 versus 8.3 months, P = 0.073) and wild-type versus mutated K-Ras (median 11.5 versus 9.3 months, P = 0.57). Grade 3/4 toxic effects included neutropenia (11.0%), thrombopenia (7%), skin toxic effect (7%) and allergic reactions (7%).

CONCLUSION

Addition of cetuximab to adjuvant gemcitabine does not seem to improve DFS or OS of unstratified pancreatic cancer patients. Trends for improved DFS in patients with wild-type K-Ras and skin toxic effect remain to be confirmed.

EGFR pathway biomarkers in erlotinib-treated patients with advanced pancreatic cancer: translational results from the randomised, crossover phase 3 trial AIO-PK0104

Background:

We aimed to identify molecular epidermal growth factor receptor (EGFR) tissue biomarkers in pancreatic cancer (PC) patients treated with the anti-EGFR agent erlotinib within the phase 3 randomised AIO-PK0104 study.

Methods:

AIO-PK0104 was a multicenter trial comparing gemcitabine/erlotinib followed by capecitabine with capecitabine/erlotinib followed by gemcitabine in advanced PC; primary study end point was the time-to-treatment failure after first- and second-line therapy (TTF2). Translational analyses were performed for KRAS exon 2 mutations, EGFR expression, PTEN expression, the EGFR intron 1 and exon 13 R497K polymorphism (PM). Biomarker data were correlated with TTF, overall survival (OS) and skin rash.

Results:

Archival tumour tissue was available from 208 (74%) of the randomised patients. The KRAS mutations were found in 70% (121 out of 173) of patients and exclusively occurred in codon 12. The EGFR overexpression was detected in 89 out of 181 patients (49%) by immunohistochemistry (IHC), and 77 out of 166 patients (46%) had an EGFR gene amplification by fluorescence in-situ hybridisation (FISH); 30 out of 171 patients (18%) had a loss of PTEN expression, which was associated with an inferior TTF1 (first-line therapy; HR 0.61, P=0.02) and TTF2 (HR 0.66, P=0.04). The KRAS wild-type status was associated with improved OS (HR 1.68, P=0.005); no significant OS correlation was found for EGFR–IHC (HR 0.96), EGFR–FISH (HR 1.22), PTEN–IHC (HR 0.77), intron 1 (HR 0.91) or exon 13 R497K PM (HR 0.83). None of the six biomarkers correlated with the occurrence of skin rash.

Conclusion:

The KRAS wild-type was associated with an improved OS in erlotinib-treated PC patients in this phase 3 study; it remains to be defined whether this association is prognostic or predictive.

Gemcitabine plus erlotinib (GE) followed by capecitabine (C) versus capecitabine plus erlotinib (CE) followed by gemcitabine (G) in advanced pancreatic cancer (APC): A randomized, cross-over phase III trial of the Arbeitsgemeinschaft Internistische Onkologie (AIO)

LBA4011

Background: Gemcitabine plus erlotinib (GE) is regarded as one standard of care for patients (pts) with APC and CE as an all-oral regimen could be a feasible option in this population. To date, the value of a prospectively defined second-line treatment is unclear in APC.

Methods: Within a prospective multicenter phase III trial, 281 pts with histologically confirmed APC and adequate organ function were randomly assigned to first-line treatment with either C (2,000 mg/m2/d, d1-14 q3w) plus E (150 mg/d, arm A) or G (1,000 mg/m2 over 30 min weekly x 7, then d1, 8, 15 q4w) plus E (150 mg/d, arm B). In case of treatment-failure (e.g. disease progression or toxicity, TTF1), pts were "crossed-over" to second-line treatment with the comparator cytostatic drug without E. The primary study endpoint was time to treatment failure of second-line therapy (TTF2); secondary endpoints included TTF1, objective response, overall survival (OS) and toxicity.

Results: Of 279 eligible pts, 60% were male and median age was 64 years; 47 pts had locally advanced and 232 metastatic disease, 141 pts (51%) received second-line chemotherapy. Objective response rate (CR+PR, ITT) to first-line treatment was 5% (A) vs. 13% (B). Currently, TTF2 is estimated with 4.4 months (mo) in arm A and 4.2 mo in arm B (HR 0.98, p=0.43), median OS is 6.9 mo (A) and 6.6 mo (B), respectively (HR 0.96, p=0.78). TTF1 was significantly prolonged in arm B (2.4 mo vs 3.4 mo; HR 0.69, p=0.0036). Hematological toxicity was more frequent with G-containing regimens, skin rash > grade 1 during E treatment occurred in 31% pts in arm A and in 43% pts in arm B. Tissue tumor samples are available from 204 pts; 123 tumors (70%) harboured a somatic KRAS mutation (mut). Pts with KRAS wildtype (wt, n=53) had an improved OS (wt: 8.0 mo vs. mut: 6.6 mo; HR 1.62, p=0.011).

Conclusions: TTF2 and OS were comparable in both arms; GE was superior compared to CE with regard to TTF1. Wt KRAS status was associated with an imprved OS in pts with APC.

[Table: see text]

Intracapillary leucocyte accumulation as a novel antihaemorrhagic mechanism in acute pancreatitis in mice

BACKGROUND

Pancreatic infiltration by leucocytes represents a hallmark in acute pancreatitis. Although leucocytes play an active role in the pathophysiology of this disease, the relation between leucocyte activation, microvascular injury and haemorrhage has not been adequately addressed.

METHODS

We investigated intrapancreatic leucocyte migration, leucocyte extravasation and pancreatic microperfusion in different models of oedematous and necrotising acute pancreatitis in lys-EGFP-ki mice using fluorescent imaging and time-lapse intravital microscopy.

RESULTS

In contrast to the current paradigm of leucocyte recruitment, the initial event of leucocyte activation in acute pancreatitis was represented through a dose- and time-dependent occlusion of pancreatic capillaries by intraluminally migrating leucocytes. Intracapillary leucocyte accumulation (ILA) resulted in dense filling of almost all capillaries close to the area of inflammation and preceded transvenular leucocyte extravasation. ILA was also initiated by isolated exposure of the pancreas to interleukin 8 or fMLP, demonstrating the causal role of chemotactic stimuli in the induction of ILA. The onset of intracapillary leucocyte accumulation was strongly inhibited in LFA-1(-/-) and ICAM-1(-/-) mice, but not in Mac-1(-/-) mice. Moreover, prevention of intracapillary leucocyte accumulation led to the development of massive capillary haemorrhages and transformed mild pancreatitis into lethal haemorrhagic disease.

CONCLUSIONS

ILA represents a novel protective and potentially lifesaving mechanism of haemostasis in acute pancreatitis. This process depends on expression of LFA-1 and ICAM-1 and precedes the classical steps of the leucocyte recruitment cascade.

Ex vivo expanded telomerase-specific T cells are effective in an orthotopic mouse model for pancreatic adenocarcinoma

Telomerase activity is over-expressed in nearly all pancreatic carcinomas, but not in chronic pancreatitis. Here, we investigated various protocols for expansion of telomerase-specific T cells for adoptive cell transfer and their use in a syngeneic pancreatic carcinoma mouse model. Telomerase-specific T cells were generated by stimulation of splenocytes from peptide-immunized donor mice with either interleukin (IL)-2, IL-15, artificial antigen-presenting cells, anti-signalling lymphocyte activation molecule (SLAM) microbeads or allogeneic dendritic cells in combination with a limited dilution assay. T cells were tested for antigen specificity in vitro and for anti-tumour activity in syngeneic mice with orthotopically implanted tumours pretreated with cyclophosphamide. The immune cells from recipients were immunophenotyped. During a period of 2 weeks, the expansion approach using IL-2 was very successful in generating a high number of telomerase-specific CD8(+) T cells without losing their function after adoptive cell transfer. Significantly slower tumour growth rate and less metastasis were observed after adoptively transferring telomerase specific CD8(+) T cells, expanded using IL-2. Further investigations showed that anti-tumour efficacy was associated with a significant shift from naive CD8(+) T cells to CD8(+) central memory T cells, as well as recruitment of a high number of dendritic cells. Remarkable amounts of telomerase-specific T cells were detectable in the tumour. Generation of telomerase-specific T cells is feasible, whereat IL-2-based protocols seemed to be most effective and efficient. Antigen-specific T cells showed significant cytotoxic activity in a syngeneic, orthotopic mouse model, whereas central memory T cells but not effector memory T cells appear to be of high importance.

Cationic liposomal paclitaxel in combination with gemcitabine in patients with advanced pancreatic cancer: A phase II trial

4526

Background: EndoTAG-1 is a novel cationic liposomal formulation of paclitaxel being developed for the treatment of solid malignancies. It acts by targeting activated negatively charged endothelial cells of tumor blood vessels. We present safety and efficacy data of a randomized, controlled phase II trial in pancreatic cancer (PC). Methods: 200 patients with advanced PC were randomized to 1st line treatment with weekly gemcitabine (GEM: 1000 mg/m2) and twice weekly infusions of EndoTAG-1 (E) at 3 different dose levels (Elow: 11 mg/m2, Emed: 22 mg/m2, Ehigh: 44 mg/m2) or GEM monotherapy. Patients were treated for 7 weeks and followed up for overall survival (OS) for at least 1 year. After finishing study treatment, any anti-tumor therapy was allowed. A subgroup of patients had the option to receive repeated cycles of combination therapy in case of at least stable disease according to RECIST until disease progression. Results: Median OS was substantially higher in the GEM+Emed and GEM+ Ehigh groups than the GEM monotherapy group. Adjusted hazard ratios for OS were 0.72 (95% CI 0.46–1.13) and 0.67 (0.43–1.07). In patients receiving >1 treatment cycle, median OS was 11.5 months (GEM+Ehigh); in the GEM+Emed group 75% of patients were alive at 1 year. Treatment with EndoTAG-1 and gemcitabine was generally well tolerated. A trend for increasing adverse event frequency with EndoTAG-1 dose was observed for infusion-related reactions associated with chills and pyrexia, and thrombocytopenia. The overall frequency of serious adverse events in the GEM+E groups was low, the most frequent SAE being pyrexia in 4 (8%) patients in the GEM+Ehigh group. There was no indication for significant organ toxicity associated with EndoTAG-1, even in patients receiving multiple treatment cycles. Conclusions: This phase II trial indicates a considerable survival benefit for patients with advanced PC receiving EndoTAG-1 in combination with gemcitabine and a favourable safety profile warranting further development of EndoTAG-1 in this indication.

[Table: see text]

Transfection with CD40L induces tumour suppression by dendritic cell activation in an orthotopic mouse model of pancreatic adenocarcinoma

OBJECTIVE

Patients with adenocarcinoma of the pancreas have only limited promising therapy options. Therefore, immunotherapeutic approaches might be considered promising and have gained importance over the last few years. In this study, CD40L gene transfer was tested as potent immunotherapy.

METHODS

The efficacy of CD40L gene transfer in initiating anti-tumour immune response was investigated in a pancreatic ductal adenocarcinoma orthotopic syngeneic mouse model. In addition, the role of dendritic cells was determined.

RESULTS

A significantly slower tumour growth rate and less metastasis were observed following administration of the CD40L plasmid. Such an effect of the plasmid was not observed in immunodeficient mice. Tumours of treated mice were found to be infiltrated with T cells and dendritic cells. The latter were mature and of myeloid origin. Tumour-infiltrating lymphocytes were tumour-specific as shown in IFN-gamma ELISPot assays. Using intravital microscopy it was possible to show a significant induction of leukocytes sticking to the tumour endothelium after CD40L treatment. Adoptive cell transfer experiments have revealed that tumour-derived dendritic cells and CD8 cells from CD40L-treated donor mice either harbour anti-tumour activity or induce it in the recipients. Distinctly, CD8 cells from donor spleens were found to migrate directly into the recipient's tumour.

CONCLUSIONS

The induction of anti-tumour activity initiated after treating mice with the CD40L plasmid was achieved. Further investigations showed that this is mediated by mature myeloid dendritic cells which activate CD8 cells. Clinical trials investigating CD40L-based therapies should be extended.

Intratumoural injection of the toll-like receptor-2/6 agonist 'macrophage-activating lipopeptide-2' in patients with pancreatic carcinoma: a phase I/II trial

This phase I/II trial examined safety and efficacy of the toll-like receptor 2/6 agonist MALP-2 in combination with gemcitabine in patients with incompletely resectable pancreas carcinomas. MALP-2 is a toll-like receptor 2/6 agonist, acts as an immunological adjuvant, and has been described recently to prolong survival in a mouse model of an orthotopic, syngeneic pancreas tumour. Male and female patients with incompletely resectable pancreas carcinomas were eligible while those with R0 or R1 resections or with peritoneal carcinosis were excluded. Ten patients were injected intratumourally during surgery with 20-30 microg MALP-2 followed by postoperative chemotherapy. Samples were taken from peripheral blood and wound secretion, and assayed for cell content, cytokine and CRP levels, and NK activity. An MALP-2 dose of 20 microg was well tolerated. Clear signs of local MALP-2 effects were presented by the influx of lymphocytes and monocytes in wound secretions, and abolishment of inhibition of NK activity. The actual mean survival is 17.1+/-4.2 months; the median survival being 9.3 months. Two patients are still alive after 31 months. Up to 20 microg MALP-2 was well tolerated, and no systemic side effects were noted. The mean survival of 17.1 months is remarkably high.

Effect of Flt3 ligand gene transfer in experimental pancreatic cancer

BACKGROUND

Fms-like tyrosine kinase 3 receptor (Flt3) is an important receptor expressed on the cell membrane of immature antigen-presenting cells. The binding of Flt3 to its ligand (FL) activates the proliferation of dendritic cells (DCs). This mechanism is currently being evaluated in the therapy of malignant tumors. The aim of the present study was to study the effect of FL gene transfer on the immune response and tumor growth in experimental pancreatic cancer.

MATERIALS AND METHODS

The rat FL was sequenced and cloned from total mRNA extract of the spleen. Transfection efficiency of subcutaneously growing rat duct-like pancreatic cancer (DSL6A) with DOTAP-/cholesterol-based liposomes was tested using a pcDNA3.1-lacZ construct. Flt3 ligand production of in vitro transfected tumor cells and in vivo transfected tumors was measured by enzyme-linked immunosorbent assay. Tumor induction was achieved in Lewis rats by a subcutaneous inoculation of syngeneic pancreatic tumor cells (DSL6A). The animals were allocated into three groups: control, mock treatment, and treatment with FL plasmid. The plasmid was injected intratumorally three times per week for 2 weeks. The total observation time was 6 weeks.

RESULTS

The tumor volume was significantly lower in the FL-transfected group during the first 3 weeks. The number of responders was significantly higher in the FL group compared with control and mock treatment. The number of CD80+ DCs in the spleen was significantly higher after FL gene transfer. The responders showed a significantly higher number of splenic natural killer (NK) cells. There were no differences of infiltrating lymphocytes, proliferation, and tumor blood vessels between the groups.

CONCLUSION

Intratumoral gene transfer of FL in rats activated proliferation of DCs and NK cells, which causes a moderate reduction of tumor growth. This improvement of local tumor control during the first weeks could be explained by an improved antigen presentation.

Coculture with dendritic cells promotes proliferation but not cytotoxic activity of γ/δ T cells

T cells bearing the gamma9/delta2 T cell receptor (TCR) have recently raised interest as non-MHC restricted effector cells against multiple myeloma. They are described to be stimulated by phosphoantigens without the need of antigen presenting cells. However, in the past a positive effect of cells of the monocyte lineage on activation of gamma/delta T cells has been shown. Monocyte derived dendritic cells (DC) are professional antigen presenting cells widely investigated as stimulators of alpha/beta T cells. But only little is known about the interaction of gamma/delta T cells and monocyte derived DC. Here, we investigated the effect of coculture of mature DC unpulsed or pulsed with ibandronate on the proliferation and cytotoxic activity of isolated gamma/delta T cells. After coculturing monocyte derived DC with isolated gamma/delta T cells, proliferation of gamma/delta T cells was enhanced as determined by the (3)H thymidine uptake assay. Also, IFN-gamma secretion was increased after coculture with DC. As DC are well known to induce activation of alpha/beta T cells we investigated whether the cytotoxic activity of gamma/delta T cells could be increased by coculture with DC. We found no difference in cytotoxic activity of gamma/delta T cells alone or cocultured with unpulsed or pulsed mature DC. Also, sensitizing of myeloma cells by addition of ibandronate could not increase lysis by gamma/delta T cells. In conclusion, monocyte derived DC are capable of stimulating proliferation and secretion of IFN-gamma of gamma/delta T cells but do not exert an effect on cytotoxic activity of gamma/delta T cells against myeloma cells.

Phase III trial of postoperative cisplatin, interferon alpha-2b, and 5-FU combined with external radiation treatment versus 5-FU alone for patients with resected pancreatic adenocarcinoma -- CapRI: study protocol [ISRCTN62866759]

After surgical intervention with curative intention in specialised centres the five-year survival of patients with carcinoma of the exocrine pancreas is only 15%. The ESPAC-1 trial showed an increased five-year survival of 21% achieved with adjuvant chemotherapy. Investigators from the Virginia Mason Clinic have reported a 5-year survival rate of 55% in a phase II trial evaluating adjuvant chemotherapy, immunotherapy and external-beam radiation.