Biomedical subjects

Thomas Giese

Publications and source records attributed to Thomas Giese.

At least 19 recordsLinked to original sources

PubMed2007

Expression and differential signaling of heregulins in pancreatic cancer cells.

The EGF family of ligands and receptors plays an important role in the pathogenesis of pancreatic ductal adenocarcinoma (PDAC) and contributes to its aggressiveness. A number of molecular approaches have been developed to block these pathways, and studies have already proven the clinical benefit of this concept in PDAC. In the present study, we sought to determine the potential role of heregulins (HRGs), a family of EGF-like growth factors, in PDAC. Quantitative RT-PCR analysis revealed that HRGs as well as its signaling ErbB receptors were present in 4 of 4 human pancreatic cancer cell lines (PCCL). HRG-beta1 stimulated the growth of 3 of 4 PCCL, whereas HRG-alpha1 inhibited cell growth in 3 of 4 cell lines. Responses towards HRGs could in part be predicted by ErbB2 and ErbB3 expression levels. HRGs induced phosphorylation of different ErbB receptors as well as activation of MAPK, p38MAPK, JNK and PI3K in a cell- and ligand-specific manner. In vivo, HRG was upregulated in pancreatic cancer tissues and localized predominantly in the cancer cells. High HRG-beta levels but not HRG-alpha levels were associated with decreased patient survival. In conclusion, HRG is expressed by pancreatic cancer cells and influences pancreatic cancer cell growth and patient survival.

Cell Line, Tumor↗

PubMed2007

Modulation of 2B4 (CD244) activity and regulated SAP expression in human NK cells.

The adapter protein SAP is important for the signal transduction of the family of SLAM-related receptors (SRR), which have important immune-modulating functions. The importance of SAP and SRR for a functional immune reaction becomes obvious in patients suffering from X-linked lymphoproliferative disease, which is characterized by non-functional SAP. Here we investigate the regulation of SAP expression in human NK cells. We demonstrate that SAP mRNA expression and protein levels are low in freshly isolated resting NK cells. IL-2 stimulation leads to an up-regulation of SAP expression, which can be enhanced by IL-12, the stimulation of TLR3 by polyinosinic-polycytidylic acid (poly(I:C))and to a lesser extent by IFN-alpha. EAT-2, a SAP-related adapter protein, is already detectable in resting NK cells and does not change its expression after IL-2 stimulation. The regulation of SAP has functional consequences for the stimulation of NK cell cytotoxicity by 2B4. In resting NK cells, 2B4 stimulation can only enhance NK cell lysis when co-triggered with other activating NK cell receptors. In IL-2-activated NK cells with high SAP expression the triggering of 2B4 alone is sufficient to induce NK cell cytotoxicity, demonstrating a correlation between the regulated SAP expression and the function of 2B4.

Antigens, CD↗

PubMed2007

IL-10 inhibits endothelium-dependent T cell costimulation by up-regulation of ILT3/4 in human vascular endothelial cells.

Effects of IL-10 on endothelium-dependent T cell activation have not been investigated in detail. We confirm expression of the IL-10 receptor and effective signaling via STAT-3 in human umbilical vein endothelial cells (HUVEC). In CD4 T cell cocultures with HUVEC, pretreatment of endothelial cells with IL-10 resulted in significant dose-dependent inhibition of CD4 T cell proliferation, which also occurred when IL-10 was removed after pretreatment before starting cocultures. Th1/Th2 polarization of proliferated T cells, endothelial nitric oxide (NO), or IL-12 production were unchanged. However, IL-10 stimulation resulted in up-regulation of SOCS-3, a negative regulator of cytokine secretion, and induction of the inhibitory surface molecules immunoglobulin-like transcript 3 and 4 (ILT3/ILT4) in EC, potentially involving glucocorticoid-induced leucine zipper (GILZ). Addition of blocking antibodies against ILT3/ILT4 to EC/T cell cocultures resulted in nearly complete reestablishment of T cell proliferation. In contrast, addition of soluble ILT3 or overexpression of ILT3 in cocultures significantly reduced T cell proliferation. No induction of foxp3+ regulatory T cells was seen. In conclusion, the T cell costimulatory potential of human EC is markedly suppressed by IL-10 due to up-regulation of ILT3/ILT4, obviously not involving generation of Treg. This identifies a novel action of IL-10 in EC and a potential therapeutical target for local immunomodulation.

Animals↗

PubMed2007

Predictive value of mucosal TNF-alpha transcripts in steroid-refractory Crohn's disease patients receiving intensive immunosuppressive therapy.

BACKGROUND: Concentrations of proinflammatory cytokines are increased in the intestinal mucosa of patients with active Crohn's disease (CD). In a prospective study we investigated whether cytokines can predict long-term remission (>6 months) in patients with steroid-refractory CD receiving treatment with infliximab or cyclophosphamide, followed by azathioprine or methotrexate. METHODS: Cytokine transcripts were quantified using real-time polymerase chain reaction (PCR) in mucosal biopsies from 19 patients with active, steroid-refractory CD before and 8 weeks after initiation of therapy. Patients were treated with cyclophosphamide (monthly treatment of 750 mg cyclophosphamide intravenously) or infliximab (5 mg/kg body weight) and were followed until relapse of the disease. Statistical analysis was performed to identify predictive factors to discriminate between patients with or without long-term remission. RESULTS: Seventeen out of 19 patients achieved remission of the disease, two patients were nonresponders, while six out of 17 patients exhibited an early recurrence. Pretreatment TNF-alpha, IL-18, MRP-14, and IL-8 transcripts were significantly correlated with long-term remission. While several cytokines, most importantly MMP-1, determined after 8 weeks were able to predict patients achieving long-term remission, only a decrease of TNF-alpha levels after 8 weeks was predictive. Overall, statistical analysis identified lower pretreatment TNF-alpha levels as the strongest predictor of long-term remission among baseline variables. CONCLUSIONS: Quantification of mucosal TNF-alpha transcripts prior to therapy allows identification of patients achieving long-term remission upon immunosuppression with infliximab or cyclophosphamide. Real-time PCR might have considerable potential in the analysis of disease activity and subsequent clinical management of patients with immunosuppressive therapies.

Adolescent↗

PubMed2006

Pharmacodynamic monitoring of cyclosporine a in renal allograft recipients shows a quantitative relationship between immunosuppression and the occurrence of recurrent infections and malignancies.

BACKGROUND: At present it is unclear which dose and consecutive blood levels of cyclosporine A (CsA) are optimal with respect to immunosuppressive efficacy and drug specific side effects at the level of individual patients. Several pharmacodynamic measures of CsA effects have been proposed, but have not become clinical routine yet. Besides the lack of practicability, the biological relevance of these assays has not been determined so far. METHODS: Residual expression of nuclear factor of activated T-cells (NFAT)-regulated genes two hours after drug intake was used as molecular pharmacodynamic marker to assess CsA effects on lymphocytes and correlated with the frequency of recurrent infections and malignancies in patients with five or more years of follow-up posttransplantation. RESULTS: Recurrent infectious complications were observed in 44% and malignancies in 20% of the 133 patients studied. Patients with a strong suppression of NFAT-regulated genes by CsA--as judged by a residual level of transcription of less than 15% after drug intake--develop more frequent infections (53% vs. 29%; P = 0.005) and malignancies (22% vs. 4%; P = 0.002). The lack of correlation between the incidence of these complications and CsA blood concentration might point to the interindividual differences in the sensitivity towards calcineurin inhibition. CONCLUSION: The data presented here reveal a clear relation between the frequency of infectious and malignant complications and the degree of suppression of NFAT-regulated genes by CsA in transplanted patients. Therefore, pharmacodynamic monitoring of CsA efficacy in transplanted patients might be a useful tool to adjust immunosuppressive therapy in individual patients.

Adult↗

PubMed2006

The neurotrophic factor artemin influences the extent of neural damage and growth in chronic pancreatitis.

BACKGROUND AND AIMS: Chronic pancreatitis is characterised by severe abdominal neuropathic pain, perineural inflammatory cell infiltrations and intrapancreatic neural growth. Artemin was recently shown to eliminate neuropathic pain and reverse neurochemical damage after nerve injury. The role of artemin and its receptor GFRalpha3 was investigated in patients with chronic pancreatitis. METHODS: Expression of artemin and its receptor GFRalpha3 was studied in chronic pancreatitis (n = 66) and normal (n = 22) pancreatic tissues by quantitative reverse transcription-polymerase chain reaction (QRT-PCR) and western blot analysis. Artemin expression was correlated with pain and pathomorphological changes (inflammation, perineural inflammatory cell infiltration, neural alterations and fibrosis). Immunohistochemistry was used to localise artemin and GFRalpha3 in the tissues. To detect sources of artemin, primary human pancreatic stellate cells (hPSCs) were isolated and analysed by QRT-PCR and immunocytology analysis. RESULTS: In chronic pancreatitis, artemin and GFRalpha3 were significantly overexpressed and located in smooth muscle cells of arteries, Schwann cells and neural ganglia. Increased levels of artemin mRNA correlated with pain severity, inflammation, perineural inflammatory cell infiltration, neural density and hypertrophy. Furthermore, the severity of fibrosis was positively related with artemin expression and neural alterations. Activated hPSCs expressed low basal levels of artemin mRNA which were upregulated by exposure to transforming growth factor (TGF)beta1. CONCLUSIONS: Overexpression of artemin in chronic pancreatitis might function as a compensatory upregulation in order to repair neural damage incurred by ongoing pancreatic inflammation. Upregulation of TGFbeta1 seems not only to increase pancreatic fibrosis but also to contribute to neural alteration by stimulating artemin expression in hPSCs. However, overexpression of endogenous artemin does not seem to be sufficient to prevent pain in chronic pancreatitis.

Abdominal Pain↗

PubMed2006

GSK-3 mediates differentiation and activation of proinflammatory dendritic cells.

The key components of the intracellular molecular network required for the expression of a specific function of dendritic cells (DCs) are as yet undefined. Using an in vitro model of human monocyte-derived DC differentiation, this study investigates the role of glycogen synthase kinase 3 (GSK-3), a multifunctional enzyme critical for cellular differentiation, apoptosis, self-renewal, and motility, in this context. We demonstrate that GSK-3 (1) inhibits macrophage development during differentiation of DCs, (2) is constitutively active in immature DCs and suppresses spontaneous maturation, and (3) acquires a proinflammatory functional status mediating high levels of IL-12, IL-6, and TNF-alpha secretion, and partially inhibits IL-10 in the context of DC activation. In particular, GSK-3 enhances IL-12p35 mRNA expression and thus the production of the proinflammatory cytokine IL-12p70 by integrating the activities of other kinases priming GSK-3 targets and the inhibitory effects of Akt-1. GSK-3 may therefore act as a key integrator of activating and inhibitory pathways involved in proinflammatory DC differentiation and activation.

Cell Differentiation↗

PubMed2006

Human inflammatory bowel disease does not associate with Lawsonia intracellularis infection.

BACKGROUND: There is increasing evidence that bacterial infection of the intestinal mucosa may contribute to the pathogenesis of inflammatory bowel diseases (IBD). In pigs, an obligate intracellular bacterium, Lawsonia intracellularis (LI), was shown to cause proliferative enteropathy (PE) of which some forms display histological and clinical similarities to human IBD. Since LI-similar Desulfovibrio spp. may infect human cells, we hypothesized that LI might be associated with the development of human IBD. RESULTS: In human intestinal tissue samples, PCR using LLG, 50SL27, LSA and strictly LI-specific 16SII primers, yielded either no amplicons or products with weak homology to human genomic sequences. Sequencing of these amplicons revealed no specificity for LI. However, amplification of DNA with less specific 16SI primers resulted in products bearing homology to certain Streptococcus species. These 16SI-amplified products were present in healthy and diseased specimens, without obvious prevalence. CONCLUSION: LI is not associated with the pathogenesis of UC or CD. Whether an immunologic response to commensal bacteria such as streptococci may contribute to the chronic inflammatory condition in IBD, remained to be determined.

DNA, Bacterial↗

PubMed2006

Differentially expressed genes in postperfusion biopsies predict early graft dysfunction after liver transplantation.

BACKGROUND: Preservation induced injury is a major contributing factor to early graft dysfunction in liver allograft recipients. We hypothesized that changes in gene expression represent the earliest indicator of ischemia/reperfusion-related injuries measurable in the graft and could be used as prognostic marker for the occurrence of graft-related complications. METHODS: We studied the expression of 67 genes, known to play a role in acute inflammatory processes by real-time polymerase chain reaction in 59 postperfusion biopsies. The level of expression was correlated with the occurrence of graft-related complications. RESULTS: We identified six genes that were significantly correlated with the occurrence of early graft dysfunction (Spearman test, two-tailed; P<0.05). High C-reactive protein (CRP) gene expression levels correlated significantly with the need of therapeutic interventions due to graft-related complications (P=0,011). Furthermore, five genes related to vascular endothelial cell physiology (CTGF, WWP2, CD274, VEGF. and its receptor FLT1) showed significantly reduced expression in the postperfusion biopsies of patients with need of therapeutic interventions due to graft-related complications in the first month (P<0.05). Using a risk score based on the expression of these five genes, complications could be predicted with 96% sensitivity (ROC analysis, specificity: 74%, positive predictive value: 72%, negative predictive value: 96%). CONCLUSION: Quantitative gene expression analysis in postperfusion biopsies may be a valuable tool to prospectively identify patients at risk for early clinical allograft dysfunction after liver transplantation.

Acute Disease↗

PubMed2006

Upregulation of CD39/NTPDases and P2 receptors in human pancreatic disease.

Chronic inflammation, fibrosis, atrophy, malignant transformation, and thromboembolic events are hallmarks of chronic pancreatic disease. Extracellular nucleotides have been implicated as inflammatory mediators in many pathological situations. However, there are minimal data detailing expression of ectonucleotidases and type-2 purinergic receptors (P2R) in chronic pancreatitis and pancreatic cancer. We have therefore defined tissue distribution and localization of the CD39 family of ectonucleotidases and associated P2R in human disease. Transcripts of ectonucleotidases (CD39 and CD39L1) together with P2R (P2X7, P2Y2, and P2Y6) are significantly increased in both chronic pancreatitis and pancreatic cancer. CD39 and CD39L1 are preferentially associated with the vasculature and stromal elements in pathological tissues. P2X7 mRNA upregulation was associated with chronic pancreatitis, and heightened protein expression was found to be localized to infiltrating cells. P2Y2 was markedly upregulated in biopsies of pancreatic cancer tissues and expressed by fibroblasts adjacent to tumors. High-tissue mRNA levels of CD39 significantly correlated with better long-term survival after tumor resection in patients with pancreatic cancer. Heightened expression patterns and localization patterns of CD39, P2X7, and P2Y2 infer associations with chronic inflammation and neoplasia of the pancreas. Our data suggest distinct roles for CD39 and P2-purinergic signaling in both tissue remodeling and fibrogenesis with respect to human pancreatic diseases.

Adult↗

PubMed2006

T cell-independent, TLR-induced IL-12p70 production in primary human monocytes.

IL-12p70 is a key cytokine for the induction of Th1 immune responses. IL-12p70 production in myeloid cells is thought to be strictly controlled by T cell help. In this work we demonstrate that primary human monocytes can produce IL-12p70 in the absence of T cell help. We show that human monocytes express TLR4 and TLR8 but lack TLR3 and TLR7 even after preincubation with type I IFN. Simultaneous stimulation of TLR4 and TLR8 induced IL-12p70 in primary human monocytes. IL-12p70 production in peripheral blood myeloid dendritic cells required combined stimulation of TLR7/8 ligands together with TLR4 or with TLR3 ligands. In the presence of T cell-derived IL-4, but not IFN-gamma, stimulation with TLR7/8 ligands was sufficient to stimulate IL-12p70 production. In monocytes, type I IFN was required but not sufficient to costimulate IL-12p70 induction by TLR8 ligation. Furthermore, TLR8 ligation inhibited LPS-induced IL-10 in monocytes, and LPS alone gained the ability to stimulate IL-12p70 in monocytes when the IL-10 receptor was blocked. Together, these results demonstrate that monocytes are licensed to synthesize IL-12p70 through type I IFN provided via the Toll/IL-1R domain-containing adaptor inducing IFN-beta pathway and the inhibition of IL-10, both provided by combined stimulation with TLR4 and TLR8 ligands, triggering a potent Th1 response before T cell help is established.

Adult↗

PubMed2006

Suppression of T-cell functions by human granulocyte arginase.

Chronic inflammation is accompanied by impaired T-cell immunity. In the mouse, myeloid cell-associated arginase accounts for the suppression of immune reactivity in various models of tumor growth and chronic infections. Here we show that arginase I is liberated from human granulocytes, and very high activities accumulate extracellularly during purulent inflammatory reactions. Human granulocyte arginase induces a profound suppression of T-cell proliferation and cytokine synthesis. This T-cell phenotype is due to arginase-mediated depletion of arginine in the T-cell environment, which leads to CD3zeta chain down-regulation but does not alter T-cell viability. Our study therefore demonstrates that human granulocytes possess a previously unanticipated immunosuppressive effector function. Human granulocyte arginase is a promising pharmacologic target to reverse unwanted immunosuppression.

Arginase↗

PubMed2006

Effects of bone sialoprotein on pancreatic cancer cell growth, invasion and metastasis.

Bone sialoprotein (BSP) is an acidic glycoprotein that plays an important role in cancer cell growth, migration and invasion. The expression, localization and possible function of BSP in chronic pancreatitis (CP) and pancreatic ductal adenocarcinoma (PDAC) were analyzed by QRT-PCR, laser capture microdissection, DNA microarray analysis, immunoblotting, radioimmunoassays and immunohistochemistry as well as cell growth, invasion, scattering, and adhesion assays. BSP mRNA was detected in 40.7% of normal, in 80% of CP and in 86.4% of PDAC samples. The median BSP mRNA levels were 6.1 and 0.9copies/microl cDNA in PDAC and CP tissues, respectively, and zero copies/microl cDNA in normal pancreatic tissues. BSP was weakly present in the cytoplasm of islet cells and ductal cells in 20% of normal pancreatic tissues. BSP was localized in the tubular complexes of both CP and PDAC, as well as in pancreatic cancer cells. Five out of 8 pancreatic cancer cell lines expressed BSP mRNA. Recombinant BSP (rBSP) inhibited Capan-1 and SU8686 pancreatic cancer cell growth, with a maximal effect of -46.4+/-12.0% in Capan-1 cells and -45.7+/-14.5% in SU8686 cells. rBSP decreased the invasion of SU8686 cells by -59.1+/-11.2% and of Capan-1 cells by -13.3+/-3.8% (P<0.05), whereas it did not affect scattering or adhesion of both cell lines. In conclusion, endogenous BSP expression levels in pancreatic cancer cells and low to absent BSP expression in the surrounding stromal tissue elements may indirectly act to enhance the proliferation and invasion of pancreatic cancer cells.

Carcinoma, Pancreatic Ductal↗

PubMed2006

In vivo peripheral expansion of naive CD4+CD25high FoxP3+ regulatory T cells in patients with multiple myeloma.

In solid tumors, leukemias, and lymphomas, increased frequencies of functional CD4+CD25(high) regulatory T cells (T(reg) cells) have been previously demonstrated. In healthy individuals, T(reg) cells consist not only of memory but also of naive T cells, which can undergo peripheral expansion and are characterized by a relative enrichment for autoreactive T-cell receptors. Here, we demonstrate in patients with premalignant monoclonal gammopathy of undetermined significance and patients with multiple myeloma that functional FoxP3(+) T(reg) cells of naive, central, and effector memory phenotype as determined by CCR7 and CD45RA expression are significantly expanded. Low frequencies of T-cell receptor excision circles in naive T(reg) cells in both healthy controls and multiple myeloma patients point to peripheral expansion as the prominent mechanism of increased frequencies of naive T(reg) cells in these cancer patients. These findings strongly suggest that the increase of functional T(reg) cells in cancer patients is a response to the process of malignant transformation.

Antigens, CD↗

PubMed2006

FXYD3 is overexpressed in pancreatic ductal adenocarcinoma and influences pancreatic cancer cell growth.

The expression and localization of FXYD domain containing ion transport regulator 3 (FXYD3), a transmembrane protein that acts as a chloride channel or chloride channel regulator, was analyzed in pancreatic tissues derived from donors and patients suffering from chronic pancreatitis (CP) or pancreatic ductal adenocarcinoma (PDAC) as well as in pancreatic cancer cells using QRT-PCR, laser-capture microdissection and microarray analysis, in situ hybridization and immunohistochemistry. FXYD3 antisense expressing T3M4 pancreatic cancer cells were generated and compared to control cells using anchorage-dependent and independent growth assays, and xenotransplantation into nude mice. FXYD3 mRNA levels were 3.4-fold increased in PDAC tissues compared to donor specimens (p = 0.006), and 3.9-fold increased in microdissected cancer cells compared to normal pancreatic ductal cells (p = 0.02). FXYD3 was localized in the tubular complexes and PanIN lesions of both CP and PDAC, as well as in pancreatic cancer cells. Downregulation of FXYD3 by stable antisense transfection increased significantly the doubling time of T3M4 pancreatic cancer cells from 44 +/- 2 hr to 55 +/- 12 hr (p = 0.02). Nude mice transplanted with antisense transfected cells displayed a significant increase in tumor doubling time from 3.3 days +/- 1.0 to 4.3 days +/- 0.43 (p = 0.058). Anchorage-independent growth and sensitivity to 5-fluorouracil, gemcitabine and cisplatin as well as to MgCl(2) were not dependent on the level of FXYD3 expression. In conclusion, overexpression of FXYD3 in pancreatic cancer may contribute to the proliferative activity of this malignancy.

Adenocarcinoma↗

PubMed2006

Pancreatic regeneration in chronic pancreatitis requires activation of the notch signaling pathway.

Chronic pancreatitis as an inflammatory process characterized by morphological changes, pancreatic dysfunction, and pain. During pancreatic injury and repair the Notch signaling pathway is reinstated. The current study analyzed this pathway in chronic pancreatitis and characterized its influence on fibrogenesis. Real-time quantitative PCR and immunohistochemistry were used for expression studies. Notch activation was determined by a specific luciferase-HES-1-reporter gene constructs. Cells were stimulated with alcohol, glucose, bile acids, and steroids. Notch-2, -3, and -4 mRNA, were overexpressed in chronic pancreatitis specimens. The ligands Jagged-1, -2, and Delta-1 were highly overexpressed. Jagged-1 and Notch receptors were observed in nerves, regenerating exocrine cells, and endocrine cells. Delta staining was present in ductal but not in acinus cells and not in nerves. Activation of Notch signaling was detectable upon cell stimulation with glucose, steroids, and bile acids. High glucose levels were further associated with increased collagen-I production. The Notch pathway is reactivated during chronic pancreatitis. Among the stimuli activating the Notch pathway are steroids, high glucose levels, and bile acids. These findings suggest a possible role of the Notch pathway during pancreatic regeneration since Jagged-1 inhibits inducible collagen-1 production, suggesting a new mechanism of tissue repair in this disease.

Animals↗

PubMed2006

The complement receptor 1, CR1 (CD35), mediates inhibitory signals in human T-lymphocytes.

The modulation the specific, adaptive immune response by complement, particularly of by complement C3, is mainly attributed to its interaction with complement receptors on B-lymphocytes. The function of complement receptors on T-lymphocytes, in contrast, is less well understood, although expression of the complement receptor (CR)1 and CR3 on T-cells has been described years ago. In the present study we investigated the effect of antibodies to CR1 on T-cell lines and peripheral T-cells of healthy donors, respectively. Antibodies to CR1 profoundly inhibited the proliferation of the T-cells; of note is, that exogenously added interleukin 2, though enhancing proliferation, did not overcome the inhibitory effect mediated by anti-CR1. While anti-CR1 had no effect on the activation of the immediate early genes c-jun or c-fos nor on the early increase of gamma interferon- or interleukin 2-specific RNA, the protein synthesis of those cytokines was inhibited. Moreover, synthesis of the proliferating cell nuclear antigen (PCNA) was reduced as was the expression of cyclins, particularly of cyclin A and cyclin D3. Taken together, the data indicate that triggering CR1 inhibits proliferation of T-lymphocytes by a mechanism operating downstream of the initial signalling events.

Cell Cycle↗

PubMed2006

The neurotrophic factor artemin promotes pancreatic cancer invasion.

OBJECTIVE: To analyze the role of Artemin in pancreatic ductal adenocarcinoma (PDAC) in terms of expression, influence on cancer cell behavior, and pain correlation. SUMMARY BACKGROUND DATA: PDAC is characterized by prominent local nerve alterations and perineural invasion, which frequently affects the extrapancreatic nerve plexus, causing severe pain and precluding curative resection. Artemin, a neurotrophic protein controlling growth, regeneration, and survival of neurons was analyzed to highlight the neuro-cancer interactions in PDAC. METHODS: Artemin and its receptors (GFRalpha3/RET) were studied in PDAC tissues and normal pancreas by Western blot analysis and immunohistochemistry. RNA expression was analyzed in pancreatic tissues (normal, cancer) and pancreatic cancer cell lines by QRT-PCR. To evaluate whether Artemin influences cancer cell proliferation and invasion, MTT-growth and Matrigel-invasion assays were used. In addition, the tissue expression of Artemin was correlated with pain in PDAC. RESULTS: Artemin and GFRalpha3/RET were both detected at enhanced levels in PDAC compared with normal pancreas, localizing predominantly in hypertrophic nerves and arterial walls, as well as in cancer cells of primary and metastatic lesions. The levels of Artemin and GFRalpha3 did not correlate with pain in PDAC patients. However, Artemin promoted pancreatic cancer cell invasion up to 5-fold, without affecting cancer cell proliferation. CONCLUSION: Artemin expression was not associated with pain in PDAC. However by increasing cancer cell invasion, Artemin seems to influence neural invasion and thereby contribute to cancer cell spreading along pancreatic nerves.

Adenocarcinoma↗