Management of patients with pancreatic cystic lesions: A case-based survey

BACKGROUND

Pancreatic cystic lesions (PCL), including intraductal papillary mucinous neoplasia (IPMN), harbor different malignant potential and the optimal management is often challenging. The present study aims to depict the compliance of experts with current consensus guidelines and the accuracy of treatment recommendations stratified by the medical specialty and hospital volume.

METHODS

An international survey was conducted using a set of 10 selected cases of PCL that were presented to a cohort of international experts on pancreatology. All presented cases were surgically resected between 2004 and 2015 and histopathological examination was available. Accuracy of the treatment recommendations was based on the European and international consensus guideline algorithms, and the histopathological result.

RESULTS

The response rate of the survey was 26% (46 of 177 contacted experts), consisting of 70% surgeons and 30% gastroenterologists/oncologists (GI/Onc). In the case of main-duct IPMN (MD-IPMN), surgeons preferred more often the surgical approach in comparison with the GI/Onc (55 versus 44%). The mean accuracy rate based on the European and international consensus guidelines, and the histopathological result, were 71/76/38% (surgeons), and 70/73/34% (GI/Onc), respectively. High-volume centers achieved insignificantly higher accuracy scores with regard to the histopathology. Small branch-duct IPMN with cysts <2 cm and malignant potential were not identified by the guideline algorithms.

CONCLUSION

The survey underlines the complexity of treatment decisions for patients with PCL; less than 40% of the recommendations were in line with the final histopathology in this selected case panel. Experts and consensus guidelines may fail to predict malignant potential in small PCL.

Endoscopic ultrasound of the colon for the differentiation of Crohn's disease and ulcerative colitis in comparison with healthy controls

BACKGROUND

Diagnosis of inflammatory bowel disease (IBD) is based on clinical presentation, colonoscopy and histology. Differentiation of Crohn's disease (CD) and ulcerative colitis (UC) can be difficult in some patients. Endoscopic ultrasound (EUS) provides high resolution images of the gastrointestinal wall (GI) and may be an alternative to differentiate CD/UC.

AIM

EUS of the GI layers in patients with IBD and healthy controls (HC) for the differential diagnosis of UC/CD in a prospective, blinded study.

METHODS

Consecutive patients with CD, UC or HC underwent EUS in the mid sigmoid colon with a forward-viewing radial echoendoscope. Mucosal, submucosal, total wall thickness (TWT) and locoregional lymphnodes (LN) were assessed by EUS in a blinded fashion. TWT was correlated with macroscopic IBD scores and histological inflammation scores.

RESULTS

Total wall thickness of 61 HC was 1.71 ± 0.02 mm, and 3.51 ± 0.15 mm in n = 52 with active IBD. In patients with active UC significant thickening of the mucosa was observed but nearly normal submucosa and m.propria. In active CD significant thickening of the submucosal layer was seen with nearly normal mucosa and m.propria [MucosaUC  = 2.08 ± 0.11 mm, MucosaCD  = 1.32 ± 0.17 mm (P = 0.0001); SubmucosaUC  = 1.01 ± 0.08 mm, SubmucosaCD  = 2.01 ± 0.22 mm (P = 0.0001)]. In 73.7% of patients with active CD, but in none with UC, paracolonic lymph nodes were detected. When mucosal-submucosal and TWT and LNs were combined, the sensitivity was 92.3% for the differentiation of active UC/CD. There was a strong correlation of TWT with histological inflammation scores (UC: r = 0.43; CD: r = 0.69).

CONCLUSIONS

Increased total wall thickness has a high positive predictive value for active IBD. EUS can differentiate active UC from CD and quantify the level of colonic inflammation.

Endoscopic ultrasound-guided fine needle aspiration training: evaluation of a new porcine lymphadenopathy model for in vivo hands-on teaching and training, and review of the literature

BACKGROUND AND STUDY AIMS

Adequate training is required to achieve successful endoscopic ultrasound (EUS)-guided fine-needle aspiration (EUS-FNA). Of the variety of training models currently available, none offers verisimilitude to the tactile feel of puncturing a human lymph node. The aim of the current study was to evaluate a new porcine lymph node model for EUS-FNA training and to evaluate its impact on trainees' performance in patients compared with the literature of other models available.

METHODS

Two trainees each performed EUS-FNA of 96 lymph nodes in 18 animals with induced lymphadenopathy (mean 1.6 cm [range 0.9-3.5 cm]). Accuracy, speed, adequacy of sampling, and trainees' performance pre- and post-training were measured. Using a questionnaire, data were gathered regarding the effect of training and comfort level in patients. Results were compared with those in the literature.

RESULTS

Trainees progressed from hands-on assistance to occasional verbal guidance toward the end of animal training. There was good correlation between puncture time and number of EUS-FNA procedures performed in all but the subcarinal location (r = - 0.17). Comparison of trainee performance in patients before and after training showed a reduction in puncture time (P = 0.0014). Questionnaire analysis revealed increased confidence in echoendoscope- and needle-handling. Comparison with other published models supports these results.

CONCLUSION

Results from the literature and the current study showed that animal training improves trainee performance, confidence, and procedural comfort when returning to patient examinations. The new model produces a realistic response that is similar to EUS-FNA in patients; this experience provides a benefit to endoscopists in terms of improved performance in patients and could be considered for use in accreditation. Due to the small numbers of trainees, larger experiences are needed to confirm training efficacy.

Prospective evaluation of malignant cell seeding after percutaneous endoscopic gastrostomy in patients with oropharyngeal/esophageal cancers

BACKGROUND AND STUDY AIMS

Insertion of a percutaneous endoscopic gastrostomy (PEG) is standard care for many patients with oropharyngeal (ENT) and esophageal malignancies in order to ensure enteral feeding. The current pull-through insertion technique involves direct contact with the tumor and case reports have demonstrated the presence of metastases at insertion sites. The aim of the current study was to prospectively evaluate the risk of malignant cell seeding and the development of abdominal wall metastases after PEG placement.

PATIENTS AND METHODS

A total of 50 consecutive patients with ENT/esophageal tumors were included. After PEG placement (40 pull-through technique, 10 direct insertion), brush cytology was taken from the PEG tubing and the transcutaneous incision site. A second cytological assessment was performed after a follow-up period of 3 - 6 months.

RESULTS

In total, 26 patients with ENT cancer, 13 with esophageal cancer, and one with esophageal infiltration of lung cancer underwent pull-through PEG placement with no immediate complications. Cytology following brushing of tubing and incision sites demonstrated malignant cells in 9 /40 cases (22.5 %). Correlation analyses revealed a higher rate of malignant seeding in older patients and in those with higher tumor stages. At follow-up, cytology was undertaken in 32 /40 patients who had undergone pull-through PEG placement. Malignant cells were present in three on cytology, resulting in a metastatic seeding rate of 9.4 %.

CONCLUSION

This study showed that malignant cells were present in 22.5 % of patients immediately after pull-through PEG placement; local metastases were verified at follow-up in 9.4 %, all of which were from esophageal squamous cell carcinoma. This risk is particularly high in the older age group and in patients with higher tumor stages. Therefore, pull-through PEG placement should be avoided in these patients and direct access PEG favored instead.

The 'N-factors' in pancreatic cancer: functional relevance of NF-κB, NFAT and Nrf2 in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) represents one of the deadliest malignancies, with an overall life expectancy of 6 months. Despite considerable advances in the understanding of the molecular mechanisms involved in the carcinogenesis of PDAC, the outcome of the disease was not significantly improved over the last 20 years. Although some achievements in molecular-targeted therapies have been made (that is, targeting the epidermal growth factor receptor by erlotinib), which already entered clinical settings, and despite the promising outcome of the FOLFIRINOX trial, there is an urgent need for improvement of the chemotherapy in this disease. A plethora of molecular alterations are thought to be responsible for the profound chemoresistance, including mutations in oncogenes and tumor suppressors. Besides these classical hallmarks of cancer, the constitutive or inducible activity of transcription factor pathways are characteristic changes in PDAC. Recently, three transcription factors-nuclear factor-κB (NF-κB), nuclear factor of activated T cells (NFAT) and nuclear factor-E2-related factor-2 (Nrf2)-have been shown to be crucial for tumor development and chemoresistance in pancreatic cancer. These transcription factors are key regulators of a variety of genes involved in nearly all aspects of tumorigenesis and resistance against chemotherapeutics and death receptor ligands. Furthermore, the pathways of NF-κB, NFAT and Nrf2 are functional, interacting on several regulatory steps, and, especially, natural compounds such as curcumin interfere with more than one pathway. Thus, targeting these pathways by established inhibitors or new drugs might have great potential to improve the outcome of PDAC patients, most likely in combination with established anticancer drugs. In this article, we summarize recent progress in the characterization of these transcription-factor pathways and their role in PDAC and therapy resistance. We also discuss future concepts for the treatment of PDAC relying on these pathways.

Endoscopic transesophageal vs. thoracoscopic removal of mediastinal lymph nodes: a prospective randomized trial in a long term animal survival model

BACKGROUND AND STUDY AIMS

In cases where biopsies remain inconclusive, removal of mediastinal lymph nodes for further analysis requires surgical means. Natural orifice transluminal endoscopic surgery (NOTES) procedures allow incision/closure of the gut wall, which might enable endoscopic excision of pre-marked nodes. The aims of the current study were to investigate the feasibility, safety, and reproducibility of lymph node generation in an animal model to enable endoscopic ultrasound-guided (EUS) lymph node removal (ELR) using transesophageal NOTES access/closure and to compare this procedure with thoracoscopic lymph node removal (TLR) in a randomized long term survival animal study.

PATIENTS AND METHODS

Lymph node creation using graphite injection was performed in 12 pigs. After randomization into ELR and TLR groups, lymph nodes were marked with newly developed anchors under EUS guidance and removed using either ELR or TLR. ELR included incision of the esophageal wall and closure after lymph node removal. The main outcome measures were success in lymph node generation, technical success of lymph node removal, complications, and comparability of ELR and TLR.

RESULTS

Generation of lymph nodes proved successful in all animals in 46/48 sites injected (96 %). Anchors were placed through the selected nodes in a mean of 9.4 minutes. TLR and ELR were successful in all cases. One bleeding occurred during esophageal incision in ELR, which was stopped endoscopically. After lymph node removal, endoscopic suturing of the incision took a mean of 18 minutes. Procedure time was longer for ELR than TLR (mean 48 vs. 42 minutes). All animals survived the procedures. Autopsy after 4 weeks showed two thoracic wall abscesses in the TLR group and none in the ELR group.  Microscopic analysis revealed well healed esophageal scars.

CONCLUSION

ELR proved to be feasible in this limited sample size and complications were not observed more frequently in this group than in the TLR group.

Granulomatous mediastinal adenopathy: can endoscopic ultrasound-guided fine-needle aspiration differentiate between tuberculosis and sarcoidosis?

BACKGROUND AND STUDY AIMS

Mediastinal lymphadenopathy may indicate diseases such as tuberculosis or sarcoidosis, and it is often difficult to establish a diagnosis when standard medical work-up is inconclusive. In this study we investigated the diagnostic yield of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in the differentiation between tuberculosis and sarcoidosis.

PATIENTS AND METHODS

In this prospective study, 72 consecutive patients with mediastinal lymphadenopathy, negative endoscopic investigations including bronchoscopic procedures, and no radiological evidence of lung cancer or other malignancies on computed tomography were enrolled. EUS-FNA and subsequent cytology, microscopy for acid-fast bacilli, and culture were performed. At least 12 months' follow-up including further investigations was included to exclude tuberculosis.

RESULTS

Adequate samples were obtained from 71/72 patients (36 male; mean age 50.2 years). No complications occurred. The final diagnosis included 30 cases of sarcoidosis, 28 of tuberculosis, four malignancies, one abscess, and nine benign lymphadenopathies. The size of lymph nodes on EUS varied from 0.5 cm to 4.2 cm. Tuberculosis nodes were significantly smaller than those in sarcoidosis. Unrelated nodes were significantly smaller than in either tuberculosis or sarcoidosis. The sensitivity, specificity, and positive and negative predictive values of EUS - FNA for tuberculosis were 86 %, 100 %, 100 %, and 91 %, respectively; those for sarcoidosis were 100 %, 93 %, 91 %, and 100 %, respectively. For culture of tuberculosis, they were 71 %, 100 %, 100 %, and 84 %, respectively. EUS - FNA led to a definite diagnosis in 64/72 cases (89 %) that had not been previously diagnosed by routine methods.

CONCLUSION

EUS - FNA offers a high diagnostic yield for the differential diagnosis of tuberculosis and sarcoidosis that have not been diagnosed by conventional methods.

Induction of human β-defensins and psoriasin in vulvovaginal human papillomavirus-associated lesions

BACKGROUND

Infections with a low-risk type of human papillomavirus (HPV) may lead to genital warts. HPV targets the basal cell layer of epithelial cells. The first line of defense is the innate immune system, which provides nonspecific protection against a variety of pathogens. The antimicrobial peptides (AMPs) α- and β-defensins, cathelicidins, psoriasin, and RNase7 are central mediators.

METHODS

The expression of various α- and β-defensins, cathelicidin LL-37, psoriasin, and RNase7 was studied in biopsy samples from 35 patients with genital warts and 25 healthy women using quantitative real-time polymerase chain reaction and immunohistochemical analysis.

RESULTS

We found a significantly higher expression of the β-defensins hBD-1 (P = .03), hBD-2 (P < 0.01), and hBD-3 (P < .001), and psoriasin (P = .001) in condylomata acuminata, compared with normal controls. The RNA and protein levels of RNase7 did not differ between infected and uninfected samples (P = .55). The α-defensins HNP 1-3, HD5, and HD6 and the cathelicidin LL-37 were scarcely detectable in normal and infected tissue.

CONCLUSIONS

The differing expression of AMPs in HPV-infected, compared with noninfected, vulvovaginal biopsy samples suggests that these peptides are important in the local immune response. Curiously, hBD-1 shows a significant induction whereas RNase7 does not, which suggests differing regulation of AMPs over the course of bacterial and viral infections.

Suppression of Map Kinases Inhibits Microglial Activation and Attenuates Neuronal Cell Death Induced by α-Synuclein Protofibrils

α-Synuclein (α-Syn) accounts, as a major component of Lewy bodies (LB), for the filamentous deposits in many cases of neurodegenerative diseases. Yet, little is known about the molecular mechanisms of neuronal loss in these diseases. The correlation between α-Syn oligomerization/aggregation and pathologies raises the key question of which molecular form of α-Syn (i.e. monomeric α-Syn, protofibrils or mature fibrils) represents the damage-inducing culprit in the scenario of synucleinopathies. We show that human α-Syn protofibrils (PFs) are potent activators of parallel proinflammatory signalling pathways (p38 and ERK1/2 MAP kinases and NF-κB) in microglial cells in vitro. Furthermore, stereotactic injection of α-Syn PFs into the substantia nigra of adult rats leads to a profound activation of microglia and adjacent neuronal cell loss, which can be attenuated by the MAP kinase inhibitor semapimod. We propose that the neurodegenerative process of α-synucleinopathies involves microglial activation through α-Syn released or extruded from cells with pathogenic α-Syn metabolism. Compounds that inhibit the MAPK/NF-κB pathways might be a promising pharmacological strategy for the treatment of the inflammatory component of synucleinopathies including PD.

Inotropic therapy for cardiac low output syndrome: comparison of hemodynamic effects of dopamine/dobutamine versus dopamine/dopexamine

OBJECTIVE

To examine the effects of a therapy with dopexamine/dopamine in comparison with a regimen of dobutamine/dopamine on the outcome of patients with profound cardiogenic shock.

MATERIAL AND METHODS

Twenty patients presenting with an acute cardiogenic shock assisted with mechanical ventilation, being refractory to a therapy with dopamine alone were analyzed. After persistence of low cardiac output syndrome (cardiac index <2.5 l/min/m2) was confirmed, patients were treated either with receiving dopexamine (2 microg/kg/min) (group 1) or dobutamine (6 microg/kg/min) (group 2) in combination with dopamine (6 microg/kg/min) for 24 hrs. Hemodynamic parameters, urine production and clinical outcome were measured at intervals throughout the study. The groups were similar with respect to demographics and risk factors and there were no significant differences in the supportive treatment and hemodynamics at baseline.

RESULTS

The dopexamine treated patients had lower myocardial oxygen consumption (9310+/-2243 mmHg O2/sec vs. 10621+/-2552 mmHg O2/sec) and lower mean arterial pressure (66+/-11 mmHg vs. 71+/-10 mmHg) after the 24 hrs treatment interval, but no one of the changes reached statistical significance. No differences were found between the two groups for other variables and the overall clinical outcome.

CONCLUSION

The present study revealed that neither substance is superior in the treatment of cardiogenic shock, even if the effect on myocardial consumption and the reported beneficial effects on renal and splanchnic functions might favour the use of dopexamine under certain circumstances.

Fatal pneumocystis jirovecii pneumonia in a case of ectopic Cushing's syndrome due to neuroendocrine carcinoma of the kidney

Immunosuppression with subsequent opportunistic infections is a well-recognized complication of severe hypercortisolism. We report a case of fatal pneumocystis jirovecii pneumonia (formerly pneumocystis carinii pneumonia) in a case of ectopic Cushing's syndrome caused by a neuroendocrine carcinoma of the kidney. The 36-year old male patient had consulted a physician because of weight gain. Further endocrine diagnostic work-up revealed ACTH-dependent hypercortisolism of non-pituitary origin. Because of rapid clinical deterioration therapy with metyrapone was initiated. A neuroendocrine carcinoma of the right kidney with regional lymph node infiltration was identified and was suspected to be the source of the ACTH excess. Before any causal therapy could be initiated, the patient developed severe pneumocystis jirovecii pneumonia and died shortly thereafter from multiorgan failure one month after he first consulted a physician. Pneumocystosis has been reported in only a few cases of Cushing's syndrome. There seems to be a relationship between the degree of hypercortisolism and the susceptibility to opportunistic infections. Since ACTH concentrations may be excessively high in ectopic Cushing's syndrome and pneumocystosis may deteriorate as a consequence of decreasing circulating cortisol levels under adrenolytic therapy, prophylaxis against pneumocystis jirovecii infection should be considered.

NF-kappaB as a molecular target in the therapy of pancreatic carcinoma

The constitutive activation of the transcription factor nuclear-factor kappa B (NF-kappaB) is a hallmark of many highly malignant tumours such as the pancreatic ductal adenocarcinoma and accounts for profound chemoresistance. Inhibition of NF-kappaB activation has been shown to be a useful strategy for increasing the sensitivity towards cytostatic drug treatment in vitro and in vivo. Moreover, various pharmacological substances (e.g. thalidomide, bortezomib, sulphasalazine) have already entered clinical studies partially showing promising results for certain types of cancer. Further studies will be needed, in particular for pancreatic ductal adenocarcinoma, to evaluate the therapeutic efficacy of appropriate combinations of a NF-kappaB inhibitor and cytostatic drugs.

Inotropic therapy for cardiac low output syndrome: comparison of hemodynamic effects of dopamine/dobutamine versus dopamine/dopexamine

OBJECTIVE

To examine the effects of a therapy with dopexamine/dopamine in comparison with a regimen of dobutamine/dopamine on the outcome of patients with profound cardiogenic shock.

MATERIAL AND METHODS

Twenty patients presenting with an acute cardiogenic shock assisted with mechanical ventilation, being refractory to a therapy with dopamine alone were analyzed. After persistence of low cardiac output syndrome (cardiac index <2.5 l/min/m2) was confirmed, patients were treated either with receiving dopexamine (2 microg/kg/min) (group 1) or dobutamine (6 microg/kg/min) (group 2) in combination with dopamine (6 microg/kg/min) for 24 hrs. Hemodynamic parameters, urine production and clinical outcome were measured at intervals throughout the study. The groups were similar with respect to demographics and risk factors and there were no significant differences in the supportive treatment and hemodynamics at baseline.

RESULTS

The dopexamine treated patients had lower myocardial oxygen consumption (9310 +/- 2243 mmHg O2/sec vs. 10621 +/- 2552 mmHg O2/sec) and lower mean arterial pressure (66 +/- 11 mmHg vs. 71 +/- 10 mmHg) after the 24 hrs treatment interval, but no one of the changes reached statistical significance. No differences were found between the two groups for other variables and the overall clinical outcome.

CONCLUSION

The present study revealed that neither substance is superior in the treatment of cardiogenic shock, even if the effect on myocardial consumption and the reported beneficial effects on renal and splanchnic functions might favour the use of dopexamine under certain circumstances.

The apoptosis-inducing effect of gastrin on colorectal cancer cells relates to an increased IEX-1 expression mediating NF-κB inhibition

Addressing the puzzling role of amidated gastrin(17) (G17) and the gastrin/CCKB/CCK2 receptor in colorectal carcinogenesis, we analysed potential candidate genes involved in G17-dependent NF-kappaB inhibition and apoptosis. The colorectal carcinoma cell line Colo320 overexpressing the wild-type CCK2 receptor (Colo320wt) underwent G17-induced apoptosis along with suppressed NF-kappaB activation and decreased expression of the antiapoptotic NF-kappaB target genes cIAP1 and cIAP2, whereas G17 was without effect on Colo320 cells expressing a CCK2 receptor bearing a loss of function mutation (Colo320mut). Gene microarray analysis revealed an elevated expression of the stress response gene IEX-1 in G17-treated Colo320wt but not Colo320mut cells. Quantitative real-time PCR and conventional RT-PCR confirmed this G17-dependent increase of IEX-1 expression in Colo320wt cells. If these cells were subjected to IEX-1 knockdown by small interfering RNA transfection, the apoptosis-inducing effect of G17 was abolished. Moreover, tumor necrosis factor alpha (TNFalpha)- or 5-FU-induced apoptosis that is greatly enhanced by G17 treatment in Colo320wt cells was prevented if IEX-1 expression was repressed. Under these conditions of blocked IEX-1 expression, the NF-kappaB activity remained unaffected by G17, in particular in Colo320wt cells co-treated with TNFalpha and also the suppressive effect of G17 on cIAP1 and cIAP2 expression was not observed anymore if IEX-1 expression was blocked. Conversely, IEX-1 overexpression in Colo320mut cells caused an increase of basal and TNFalpha- or 5-FU-induced apoptosis, an effect not further triggered by G17 treatment. Using a xenograft tumor model in severe combined immune deficiency mice, we could show that experimental systemic hypergastrinemia induced by the administration of omeprazole led to enhanced apoptosis as well as to a marked increase of IEX-1 expression in Colo320wt tumors, but not in Colo320mut tumors. These observations indicate that the proapoptotic effect of G17 on human colon cancer cells expressing the wild-type CCK2 receptor is mediated by IEX-1, which modulates NF-kappaB-dependent antiapoptotic protection and thereby exerts tumor-suppressive potential.

Acquired chemoresistance in pancreatic carcinoma cells: induced secretion of IL-1beta and NO lead to inactivation of caspases

Pancreatic cancer exhibits profound chemoresistance resulting either from pre-existing (intrinsic) mechanisms, or from anticancer drug treatment itself (acquired chemoresistance). To identify molecular alterations leading to acquired chemoresistance, the chemosensitive pancreatic carcinoma cell line PT45-P1 was exposed to low-dose treatment with etoposide for 6 weeks. Afterwards, these cells (PT45-P1res) were much more resistant to high-dose treatment with anticancer drugs than parental cells. Among several differentially expressed genes in PT45-P1res cells, IL-1beta was most significantly upregulated, a finding in line with our previous observation that IL-1beta accounts for intrinsic chemoresistance of pancreatic carcinoma cells. Elevated IL-1beta expression in PT45-P1res cells was confirmed by real-time PCR and ELISA, and treatment with the IL-1 receptor antagonist restored drug-induced apoptosis. The increased IL-1beta secretion was accompanied by an elevated formation of nitric oxide (NO) and a NO-dependent inhibition of the etoposide-induced caspase-3/-7/-8/-9 activity. Caspase activation was restored either by the iNOS inhibitor 1400W, the reducing agent dithiothreitol or the IL-1 receptor antagonist, resulting in greater sensitivity towards anticancer drug treatment. Conversely, IL-1beta or the NO-donor SNAP decreased caspase activation and apoptosis in etoposide-treated PT45-P1 cells. These data confirm IL-1beta and NO as determinants of chemoresistance in pancreatic cancer, and indicate that the intrinsic and acquired chemoresistance rely to some extent on common molecular targets beneficial for improved therapeutical strategies.

The expression of immediate early gene X-1 (IEX-1) is differentially induced by retinoic acids in NB4 and KG1 cells: possible implication in the distinct phenotype of retinoic acid-responsive and -resistant leukemic cells

In a cell-type- and stimulus-dependent fashion, the early response gene immediate early gene X-1 (IEX-1) is involved in growth control and modulation of apoptosis. The present study demonstrates that, in the two acute promyelocytic leukemia (APL) cell lines NB4 and KG1, exhibiting distinct responsiveness to retinoic acids (RAs), IEX-1 expression is rapidly (30-60 min) induced by all-trans- or cis-RA and independently of other signal transduction mediators, such as TNFalpha, NF-kappaB or MAP kinases. In NB4 cells (expressing PML-RARalpha), this increase is transient and completely reversible, along with a cell cycle arrest, ongoing differentiation and lower sensitivity to anti-cancer-drug-induced apoptosis. In contrast, the RA-induced IEX-1 expression in KG1 cells (expressing PLZF-RARalpha) persists over days, along with continued cell cycle progression and increased apoptotic sensitivity. Furthermore, two functional RA-response elements in the IEX-1 promoter were identified by gel shift and luciferase reporter gene assays. IEX-1 might be a rather unique transcriptional target of the two X-RARalpha fusion receptors exhibiting distinct responsiveness to RAs. Following a different time course of direct transcriptional induction by PML-RARalpha and PLZF-RARalpha in NB4 and KG1 cells, respectively, IEX-1 expression may be involved in the modified actions of these receptors and the distinct phenotypes of APL cells.

Multiple and synergistic deregulations of apoptosis-controlling genes in pancreatic carcinoma cells

Inability to die by apoptosis is one of the reasons for the deregulated growth of tumour cells and the frequently observed failure of chemotherapy. In this study we thought to identify the common and functionally important characteristics responsible for the apoptosis resistance of pancreatic tumour cells. We analysed cell surface expression level of death receptors CD95 and TRAIL-R1-4 as well as the expression profile of sixteen apoptosis-relevant proteins in five pancreatic carcinoma cell lines Capan1, Colo357, PancTuI, Panc89 and Panc1. These data were evaluated in the context of sensitivity towards anti-CD95 and TRAIL-mediated apoptosis. Here we report that except for resistant Panc1 cells, which only marginally expressed CD95, all other cell lines showed comparable levels of CD95 and TRAIL receptors irrespectively of their apoptotic phenotype. Interestingly, we found that the elevated expression of FLIP, Bcl-x_L and IAP in parallel with a downregulation of FADD and Bid was common for the resistant cell lines. Consequently, stable overexpression of XIAP, Bcl-x_L or dominant negative FADD in sensitive cells significantly reduced the death receptor mediated apoptosis while the overexpression of Bid rendered the resistant cells sensitive.

NFkappaB-dependent chemoresistance in solid tumors

The Rel/NFkappaB family of transcription factors is involved in multiple cellular processes, including inflammation, cell cycle regulation, apoptosis and oncogenesis. Constitutive activation of NFkappaB has been described in a great number of solid tumors and this activation appears to support cancer cell survival and to reduce the sensitivity against chemotherapeutic drugs. Additionally, some of these drugs induce this transcription factor themselves and through this mechanism lower their cytotoxic potential. Inhibition of NFkappaB by various means has been shown to enhance the sensitivity to antineoplastic- or radiation-induced apoptosis in vitro and in vivo. Furthermore, suppression of NFkappaB results in attenuation of cancer cachexia and metastasis in some mouse tumor models. Studies are underway to further delineate the role of NFkappaB in cancer cell survival, growth and resistance to standard chemotherapy and radiation regimens. Moreover, the effects of novel therapeutic agents which specifically target NFkappaB proteins are currently being assessed in experimental models of cancer cell growth both in vitro and in vivo. In this review, we discuss the possible involvement of NFkappaB in the chemoresistance of various solid tumors and potential future treatment strategies based on NFkappaB inhibition.

Thrombin as a survival factor for cancer cells: thrombin activation in malignant effusions in vivo and inhibition of idarubicin-induced cell death in vitro

OBJECTIVES

The aim of the experiments shown here, is to demonstrate exemplarily that thrombin can be a survival factor for malignant cells.

METHODS

Activation of the coagulation system has been examined in patients with acute myeloid leukemia (AML) and non-Hodgkin lymphoma (NHL) before and after chemotherapy as well as in malignant effusions of heavily pretreated patients with solid tumors. Thrombin receptor expression (PAR-I) has been examined on HL-60 cells; the effect ofthrombin on the proliferation of the cells and inhibition of apoptosis induction by idarubicin has been shown.

RESULTS

Using fibrinopeptide A as an indirect parameter for thrombin activation, we found elevated levels in patients with AML and NHL before and a significant 2-fold increase after chemotherapy (p < 0.02 for the AML group; p < 0.0006 for the NHL group). Apparently, this does not only affect patients with hematological diseases, but also with solid tumors. In order to find out if the tumor cells directly activate thrombin, we examined malignant effusions of patients with different solid tumors. Comparing prothrombin fragment 1 + 2 in ascites and pleural effusions with the patients' serum levels, we found it significantly increased in all cases (mean of 1.96 +/- 0.5 nmol/l in the serum vs. 12.1 +/- 3.6 nmol/l in effusions; p < 0.001). The majority of patients presented elevated serum levels. Additionally, we incubated HL-60 cells (human promyelocytic leukemia) with thrombin prior to treatment with idarubicin. Expression of thrombin receptor (PAR-1) could be verified by FACS-analysis using a monoclonal antibody. HL-60 cells responded with increased proliferation to thrombin exposure with concentrations between 0.3 and 3 U/ml. This effect could be abolished by the addition of hirudin, demonstrating thrombin specificity. In these concentrations, thrombin was able to abrogate the induction of apoptosis by idarubicin completely (p < 0.005).

CONCLUSIONS

Here we give evidence for the role of thrombin as a resistance factor for tumor cells towards chemotherapy. In the light of the fact that thrombin is regularly activated in cancer patients, these findings indicate that thrombin is a clinically relevant cellular resistance factor. A number of pre-clinical and clinical studies imply that inhibition of the coagulation system, e.g. by low-molecular weight heparins or warfarin, increases the effect of chemotherapy.

FAP-1 in pancreatic cancer cells

In this study we investigated the functional role of FAP-1 as a potential inhibitor of CD95 (Fas, APO-1)-mediated apoptosis in pancreatic cancer cells. Stable transfection of the CD95-sensitive, FAP-1-negative cell line Capan-1 with an FAP-1 cDNA resulted in a strongly decreased sensitivity to CD95-induced apoptosis, as measured by DNA fragmentation and caspase-3 activity. Inhibition of cellular protein tyrosine phosphatases with orthovanadate dose-dependently increased CD95-induced apoptosis in CD95-resistant FAP-1-positive Panc89 and Capan-1-FAP-1 cells almost to the level seen in wild-type Capan-1 cells. Blocking the CD95/FAP-1 interaction in Panc89 cells by cytoplasmic microinjection of a synthetic tripeptide mimicking the C terminus of CD95 resulted in a mean 5.5-fold increase in apoptosis compared to cells that received a control peptide. Using confocal laser scanning microscopy we show that in Panc89 cells FAP-1 is mainly associated with the Golgi complex and with peripheral vesicles. FAP-1 displayed enhanced colocalization with CD95 upon CD95 stimulation in the Golgi complex but not in surface-associated vesicles. This correlated with a decrease in plasma membrane staining for CD95 as determined by FACS analysis. Inhibition of Golgi anterograde transport by brefeldin A abolished the anti-CD95-induced colocalization of FAP-1 and CD95 as well as the decrease in cell-surface-associated CD95. Finally, we demonstrate by immunohistochemistry that FAP-1 is strongly expressed in tumor cells from pancreatic carcinoma tissues. Taken together, these results show that FAP-1 can protect pancreatic carcinoma cells from CD95-mediated apoptosis, probably by preventing anti-CD95-induced translocation of CD95 from intracellular stores to the cell surface.

CD95 and TRAIL receptor-mediated activation of protein kinase C and NF-kappaB contributes to apoptosis resistance in ductal pancreatic adenocarcinoma cells

The molecular alterations in tumour cells leading to resistance towards apoptosis induced by CD95 and TRAIL-receptors are not fully understood. We report here that the stimulation of the CD95- and TRAIL-resistant human pancreatic adenocarcinoma cell line PancTuI with an agonistic anti-CD95 antibody or TRAIL resulted in activation of protein kinase C and NF-kappaB. Inhibition of protein kinase C by Gö6983 sensitized these cells to apoptotic challenges and strongly diminished activation of NF-kappaB by anti-CD95 and TRAIL. Similarly, inhibition of NF-kappaB by MG132 or by transient transfection with a dominant negative mutant of IkappaBalpha restored the responsiveness of PancTuI cells to both death ligands. In the CD95 and TRAIL-sensitive cell line Colo357 the induction of protein kinase C and NF-kappaB following activation of CD95 and TRAIL-R was very moderate compared with PancTuI cells. However, pre-incubation of these cells with PMA strongly reduced their apoptotic response to anti-CD95 and TRAIL. Taken together, we show that activation of protein kinase C operates directly in a death receptor-dependent manner in PancTuI cells and protect pancreatic tumour cells from anti-CD95 and TRAIL-mediated apoptosis by preventing the loss DeltaPsim and Cytochrome c release as well as by induction of NF-kappaB.

Functional disruption of IEX-1 expression by concatemeric hammerhead ribozymes alters growth properties of 293 cells

The early response gene IEX-1 modulates apoptosis and cell growth in a poorly defined fashion. Here, we describe the effect of hammerhead ribozymes specifically disrupting IEX-1 expression in 293 cells. Compared to vector control, 293 cells exhibit a reduced growth rate and a slowed cell cycle progression, when stably transfected with a concatemeric ribozyme construct. In addition, these 293 cells were much less sensitive to apoptosis induced by an activating Fas/CD95 antibody or by the anti-cancer drugs etoposide and doxorubicin. By modulating the cell cycle, IEX-1 might be part of a growth signal if favourable growth conditions prevail, whereas under unfavourable conditions, i.e. death receptor activation, IEX-1 facilitates apoptosis.

Inhibition of NF-kappaB sensitizes human pancreatic carcinoma cells to apoptosis induced by etoposide (VP16) or doxorubicin

The transcription factor NF-kappaB has anti-apoptotic properties and may confer chemoresistance to cancer cells. Here, we describe human pancreatic carcinoma cell lines that differ in the responsiveness to the topoisomerase-2 inhibitors VP16 (20 microM) and doxorubicin (0.3 microM): Highly sensitive T3M4 [corrected] and PT45-P1 cells, and Capan-1 and A818-4 cells that were almost resistant to both anti cancer drugs. VP16, but not doxorubicin, transiently induced NF-kappaB activity in all cell lines, whereas basal NF-kappaB binding was nearly undetectable in T3M4 [corrected] and PT45-P1 cells, but rather high in Capan-1 and A818-4 cells, as demonstrated by gel-shift and luciferase assays. Treatment with various NF-kappaB inhibitors (Gliotoxin, MG132 and Sulfasalazine), or transfection with the IkappaBalpha super-repressor, strongly enhanced the apoptotic effects of VP16 or doxorubicin on resistant Capan-1 and 818-4 cells. Our results indicate that under certain conditions the resistance of pancreatic carcinoma cells to chemotherapy is due to their constitutive NF-kappaB activity rather than the transient induction of NF-kappaB by some anti-cancer drugs. Blockade of basal NF-kappaB activity by well established drugs efficiently reduces chemoresistance of pancreatic cancer cells and offers the potential for improved therapeutic strategies.

Expression of the NF-kappa B target gene IEX-1 (p22/PRG1) does not prevent cell death but instead triggers apoptosis in Hela cells

P22PRG1/IEX-1 is a putative NF-kappaB target gene implicated in the regulation of cellular viability. Here, we show that in HeLa cells TNFalpha induces expression of p22PRG1/IEX-1 in an NF-kappaB dependent fashion. Blockade of NF-kappaB activation by various NF-kappaB inhibitors abolished TNFalpha-induced p22PRG1/IEX-1 expression and increased the sensitivity to apoptosis induced by TNFalpha, an activating Fas-antibody or the anti-cancer drug etoposide. Surprisingly, ectopic expression of p22PRG1/IEX-1 in HeLa cells transfected with an inducible p22PRG1/IEX-1-expression vector augments the susceptibility to apoptosis initiated by death-receptor ligands or by etoposide. In addition, p22PRG1/IEX-1 expressing HeLa cells exhibit an accelerated progression through the cell cycle. Transfection of an antisense hammerhead ribozyme targeted to p22PRG1/IEX-1 reduced the speed in cell cycle progression and decreased the apoptotic response to death ligands. Our data demonstrate that p22PRG1/IEX-1 is specifically induced during NF-kappaB activation, but this seems not to be related to the anti-apoptotic actions of NF-kappaB. Instead, NF-kappaB dependent recruitment of p22PRG1/IEX-1 might be related to a modulation in the cell cycle, and hereby, p22PRG1/IEX-1 may accelerate cell growth on the one hand, but may trigger apoptosis on the other. Oncogene (2001) 20, 69 - 76.

[Diagnosis of recurrences of head and neck carcinoma with the tumor marker SSC-antigen]

BACKGROUND

The follow-up of squamous cell carcinomas of the head and neck is often challenging. Due to tissue alteration and anatomic changes after primary treatment or submucosal tumor growth, recurrences are sometimes detected very late. The tumor marker SCC-Antigen (SCC-Ag) may provide additional information for early detection of such tumor recurrences.

PATIENTS

Serum levels of SCC-Ag in 578 patients with primary squamous cell carcinomas of the head and neck were assayed by SCC-RIA and IMx-SCC before treatment and every 2-3 months during follow-up. During the observation period of 30-84 (mean 50) months, 179 recurrences were verified by histologic examination.

RESULTS

Seventy-seven patients (43%) with tumor recurrence showed elevated serum levels of SCC-Ag (< 2.0 ng/ml). Fifty-eight (32%) of them exhibited elevated levels of SCC-Ag up to 11 months (mean 6.1 months) prior to histopathologic diagnosis. This mainly became evident in 48 (83%) patients whose SCC-Ag serum levels were elevated before treatment.

CONCLUSION

Use of SCC-Antigen in head and neck tumors follow-up can provide early evidence of almost one third of all recurrences of squamous cell carcinomas of the head and neck. For clinical purposes, we recommend an initial analysis of the SCC-Ag serum level in every patient with primary squamous cell carcinoma of the head and neck. The SCC levels of all SCC positive patients should be closely monitored. Elevated SCC should be regarded as a potential early sign for recurrence and therefore indicates the need for intensified follow-up. Depending on the individual situation this should include ultrasonography, CT, MRI and especially frequent endoscopy in general anesthesia with multiple biopsies of suspicious regions.

The putative apoptosis inhibitor IEX-1L is a mutant nonspliced variant of p22(PRG1/IEX-1) and is not expressed in vivo

IEX-1L has been claimed to act as an apoptosis inhibitor involved in NFkappaB-mediated survival in Jurkat cells [Wu et al. (1998) Science 281, 998-1001]. It represents a mutant nonspliced variant of the early response gene p22(PRG1/IEX-1) exhibiting one insertion and two deletions compared to the genomic sequence of p22(PRG1/IEX-1). Direct DNA sequencing of PCR products generated from human genomic DNA only detected the regular genomic sequence of p22(PRG1/IEX-1). No IEX-1L mRNA could be identified by RT-PCR analysis and subsequent DNA sequencing of total, nuclear, or cytoplasmic RNA fractions from PMA-stimulated Jurkat cells. The only functional transcript residing in the cytoplasm is regularly spliced p22(IEX-1/PRG1) mRNA. Substantial amounts of nonmutated nonspliced p22(IEX-1/PRG1) pre-mRNA were identified in the nucleus. Thus, IEX-1L seems to be a mutant variant of p22(IEX-1/PRG1) not existing in vivo. Antiapoptotic effects obviously represent transdominant negative inhibition of endogenous p22(PRG1/IEX-1) in Jurkat cells and several other tumor cell lines.

The promoter of human p22/PACAP response gene 1 (PRG1) contains functional binding sites for the p53 tumor suppressor and for NFkappaB

We describe functional binding sites for the tumor suppressor p53 and for NFkappaB residing in the promoter of the novel human early response gene p22/PRG1 (IEX-1/DIF-2). Gel shift and supershift assays demonstrate binding of p53 and NFkappaB to their corresponding sites in vitro. CAT-reporter gene assays show transactivation of the human p22/PRG1 promoter by p53 in Hep3B cells stably transfected with a temperature-sensitive mutant p53, but not in p53-deficient Hep3B cells. TNF alpha induced NFkappaB dependent transactivation was shown in HepG2 cells or in 818-4 pancreatic cancer cells. These data imply that human p22/PRG1 is a target gene for p53 and NFkappaB involved in growth regulation and stress response.