Purpose Pancreatic ductal adenocarcinoma (PDAC) is currently one of the leading causes of cancer ... more Purpose Pancreatic ductal adenocarcinoma (PDAC) is currently one of the leading causes of cancer death worldwide. Therefore, building further subgroups as well as enabling individual patient therapy and diagnostics are needed. X-linked inhibitor of apoptosis protein (XIAP) is known to modulate apoptotic and inflammatory pathways. Its expression was found to correlate with patients’ survival in other tumor entities. This study aims to examine the role of XIAP in patients with PDAC in relation to the inflammatory microenvironment. Methods The PANCALYZE multicenter study group included 257 patients with PDAC. Paraffin-embedded tumor samples were stained immunohistochemically for CD3, CD20, CD38, CD56, CD66b, CD117, and CD163 and XIAP. These stainings were further analyzed digitally with QuPath and survival analyses were done. Results XIAP-positive patients with T-cell, respectively, neutrophil enriched tumors survived significantly longer compared to XIAP-negative patients (CD3: 37.6 v...
(1) Background: IL-17A accelerates pancreatic intraepithelial neoplasia (PanIN) progression. In t... more (1) Background: IL-17A accelerates pancreatic intraepithelial neoplasia (PanIN) progression. In this study, we examined whether IL-17A/IL-17RA promotes pancreatic ductal adenocarcinoma (PDAC) aggressiveness in terms of survival and cancer stem cell modulation. (2) Methods: In vitro, the wound-healing assay, the sphere formation assay, and flow cytometry were applied to assess cancer stem cell features. In vivo, pancreatic tumors were induced in C57BL/6 mice using electroporation with oncogenic plasmids (P53-/-R172H; KrasG12V). Anti-IL-17 antibodies were administered as immunotherapy. We analyzed IL-17A/IL-17RA related survival using publicly available transcriptomic data (n = 903). (3) Results: IL-17A/IL-17RA expression was not related to survival in PDAC patients. IL-17A neither induces stem cell markers nor increases sphere formation and cell motility in vitro. Blocking the IL-17A/IL-17RA axis in a murine pancreatic cancer model did not improve the survival of mice, but reduced the tumor burden slightly. (4) Conclusions: IL-17A does not promote stem cell expansion in PDAC cell lines. Blocking IL-17A/IL-17RA signaling does not interfere with pancreatic cancer development and progression and may not be considered as a promising monotherapy for PDAC.
Pancreatic cancer features elaborate mechanisms of immune evasion. The potential of new immune mo... more Pancreatic cancer features elaborate mechanisms of immune evasion. The potential of new immune molecules was explored to restore the antitumor immune response. If these immune molecules are associated with poor survival, specific drugs could take effect. Here, we analyze the expression of VISTA, LAG3, IDO, and TIM3 on tumor-infiltrating lymphocytes (TILs) and its impact on patient survival. We analyzed 153 pancreatic cancer patients from the prospectively managed database of the multicentered PANCALYZE study. Immunohistochemistry on a tissue microarray assessed VISTA, LAG3, IDO, and TIM3 expression of TILs from the patients undergoing primary resection. Complementarily, we analyzed publicly available transcriptomic data (n = 903). Successful completion of chemotherapy, and lymph node status were independent predictors of survival in the multivariate analysis of the clinicopathologic parameters. Fifteen tumors were exclusively VISTA-positive, thirteen tumors expressed VISTA together ...
In pancreatic ductal adenocarcinoma (PDAC), the tumor stroma constitutes most of the cell mass an... more In pancreatic ductal adenocarcinoma (PDAC), the tumor stroma constitutes most of the cell mass and contributes to therapy resistance and progression. Here we show a hitherto unknown metabolic cooperation between pancreatic stellate cells (PSCs) and tumor cells through Interleukin 17B/Interleukin 17B receptor (IL-17B/IL-17RB) signaling. Tumor-derived IL-17B carrying extracellular vesicles (EVs) activated stromal PSCs and induced the expression of IL-17RB. PSCs increased oxidative phosphorylation while reducing mitochondrial turnover. PSCs activated tumor cells in a feedback loop. Tumor cells subsequently increased oxidative phosphorylation and decreased glycolysis partially via IL-6. In vivo, IL-17RB overexpression in PSCs accelerated tumor growth in a co-injection xenograft mouse model. Our results demonstrate a tumor-to-stroma feedback loop increasing tumor metabolism to accelerate tumor growth under optimal nutritional conditions.
Background To date, patients with metastasized pancreatic ductal adenocarcinoma (PDAC M1) are reg... more Background To date, patients with metastasized pancreatic ductal adenocarcinoma (PDAC M1) are regarded as a uniform collective. We hypothesize the existence of oligometastatic disease (OMD): a state of PDAC M1 disease with better tumor biology, limited metastasis, and increased survival. Methods Data of 128 PDAC M1 patients treated at the University of Cologne between 2008 and 2018 was reviewed. Interdependence between clinical parameter was calculated using the Mann-Whitney U-Test. Survival curves were generated using the Kaplan-Meier method and analyzed using the log-rank test. Results Eighty-one (63%) patients had metastases confined to one organ (single organ metastasis, SOG) whereas the remaining 47 (37%) showed multiple metastatic sites (multi-organ metastasis, MOG). Survival analysis revealed a median overall survival (OS) of 12.2 months for SOG vs 4.5 months for MOG (95% CI 5.7–9.8; p < 0.001). We defined limited disease by the presence of ≤4 metastases in liver or lung. ...
Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers worldwide and effective... more Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers worldwide and effective therapy remains a challenge. IFIT3 is an interferon-stimulated gene with antiviral and pro-inflammatory functions. Our previous work has shown that high expression of IFIT3 is correlated with poor survival in PDAC patients who receive chemotherapy suggesting a link between IFIT3 and chemotherapy resistance in PDAC. However, the exact role and molecular mechanism of IFIT3 in chemotherapy resistance in PDAC has been unclear. Methods: A group of transcriptome datasets were downloaded and analyzed for the characterization of IFIT3 in PDAC. Highly metastatic PDAC cell line L3.6pl and patient-derived primary cell TBO368 were used and IFIT3 knockdown and the corresponding knockin cells were established for in vitro studies. Chemotherapy-induced apoptosis, ROS production, confocal immunofluorescence, subcellular fractionation, chromatin-immunoprecipitation, co-immunoprecipitation and mass spectrometry analysis were determined to further explore the biological role of IFIT3 in chemotherapy resistance of PDAC. Results: Based on PDAC transcriptome data, we show that IFIT3 expression is associated with the squamous molecular subtype of PDAC and an increase in inflammatory response and apoptosis pathways. We further identify a crucial role for IFIT3 in the regulation of mitochondria-associated apoptosis during chemotherapy. Knockdown of IFIT3 attenuates the chemotherapy resistance of PDAC cells to gemcitabine, paclitaxel, and FOLFIRINOX regimen treatments, independent of individual chemotherapy regimens. While IFIT3 overexpression was found to promote drug resistance. Co-immunoprecipitation identified a direct interaction between IFIT3 and the mitochondrial channel protein VDAC2, an important regulator of mitochondria-associated apoptosis. It was subsequently found that IFIT3 regulates the post-translational modification-O-GlcNAcylation of VDAC2 by stabilizing the interaction of VDAC2 with O-GlcNAc transferase. Increased O-GlcNAcylation of VDAC2 protected PDAC cells from chemotherapy induced apoptosis. Conclusions: These results effectively demonstrate a central mechanism by which IFIT3 expression can affect chemotherapy resistance in PDAC. Targeting IFIT3/VDAC2 may represent a novel strategy to sensitize aggressive forms of pancreatic cancer to conventional chemotherapy regimens.
International Journal of Biological Sciences, 2019
Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal malignancies worldwide. PDAC pro... more Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal malignancies worldwide. PDAC prognostic and diagnostic biomarkers are still being explored. The aim of this study is to establish a robust molecular signature that can improve the ability to predict PDAC prognosis. 155 overlapping differentially expressed genes between tumor and non-tumor tissues from three Gene Expression Omnibus (GEO) datasets were explored. A least absolute shrinkage and selection operator method (LASSO) Cox regression model was employed for selecting prognostic genes. We developed a 6-mRNA signature that can distinguish high PDAC risk patients from low risk patients with significant differences in overall survival (OS). We further validated this signature prognostic value in three independent cohorts (GEO batch, P < 0.0001; ICGC, P = 0.0036; Fudan, P = 0.029). Furthermore, we found that our signature remained significant in patients with different histologic grade, TNM stage, locations of tumor entity, age and gender. Multivariate cox regression analysis showed that 6-mRNA signature can be an independent prognostic marker in each of the cohorts. Receiver operating characteristic curve (ROC) analysis also showed that our signature possessed a better predictive role of PDAC prognosis. Moreover, the gene set enrichment analysis (GSEA) analysis showed that several tumorigenesis and metastasis related pathways were indeed associated with higher scores of risk. In conclusion, identifying the 6-mRNA signature could provide a valuable classification method to evaluate clinical prognosis and facilitate personalized treatment for PDAC patients. New therapeutic targets may be developed upon the functional analysis of the classifier genes and their related pathways.
Background: In the present study we review and discuss the current evidence and suggest how to pr... more Background: In the present study we review and discuss the current evidence and suggest how to proceed in the management of oligometastatic disease in upper gastrointestinal cancer. Methods: An electronic search of the PubMed database for relevant articles was performed. Results: Both the search for ‘oligometastasis', ‘oligometastases', ‘oligometastatic', ‘oligometastatic disease' as well as ‘esophageal' and ‘esophageal cancer' and the search for ‘oligometastasis', ‘oligometastases', ‘oligometastatic', ‘oligometastatic disease' as well as ‘gastric', ‘gastric cancer', ‘stomach', and ‘stomach cancer' yielded very few studies. Most data need to be extrapolated in general studies on oligometastatic diseases of different origins. No randomized controlled trial could be found. Conclusion: In the absence of data to formulate recommendations on how to proceed in the treatment of oligometastatic disease in upper gastrointestinal cancer,...
Cancer stem cells (CSCs) have been identified as a subpopulation of stem-like cancer cells with t... more Cancer stem cells (CSCs) have been identified as a subpopulation of stem-like cancer cells with the ability of self-renewal and differentiation in hematological malignancies and solid tumors. Pancreatic cancer is one of the most lethal cancers worldwide. CSCs are thought to be responsible for cancer initiation, progression, metastasis, chemoresistance, and recurrence in pancreatic cancer. In this review, we summarize the characteristics of pancreatic CSCs and discuss the mechanisms involved in resistance to chemotherapy, the interactions with the niche, and the potential role in cancer immunoediting. We propose that immunotherapy targeting pancreatic CSCs, in combination with targeting the niche components, may provide a novel treatment strategy to eradicate pancreatic CSCs and hence improve outcomes in pancreatic cancer.
Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies today with an urge... more Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies today with an urgent need for novel therapeutic strategies. Biomarker analysis helps to better understand tumor biology and might emerge as a tool to develop personalized therapies. The aim of the study is to investigate four promising biomarkers to predict the clinical course and particularly the pattern of tumor recurrence after surgical resection. Patients undergoing surgery for PDAC can be enrolled into the PANCALYZE trial. Biomarker expression of CXCR4, SMAD4, SOX9 and IFIT3 will be prospectively assessed by immunohistochemistry and verified by rt.-PCR from tumor and adjacent healthy pancreatic tissue of surgical specimen. Immunohistochemistry expression pattern of all four biomarkers will be combined into a single score. Beginning with the hospital stay clinical data from enrolled patients will be collected and followed. Different adjuvant chemotherapy protocols will be used to create subgroups. The...
Background: Liver metastases from breast cancer (LMBC) are typically considered to indicate syste... more Background: Liver metastases from breast cancer (LMBC) are typically considered to indicate systemic disease spread and patients are most often offered systemic palliative treatment only. However, retrospective studies suggest that some patients may have improved survival with local treatment of their liver metastases compared to systemic therapy alone. In the absence of randomized trials, it is important to identify patient characteristics indicating that benefit from local treatment can be expected. Methods: 59 patients undergoing radiofrequency ablation (RFA), interstitial brachytherapy (BT), or radioembolization (RE) of LMBC as a salvage treatment were studied. Potential factors influencing survival were analyzed in a multivariate Cox model. For factors identified to have an independent survival impact, Kaplan-Meier analysis and comparison of overall survival (OS) using the log-rank test was performed. Results: Median OS following local interventional treatment was 21.9 months. Considering only factors evaluable at treatment initiation, maximum diameter of liver metastases (≥3.9 cm; HR: 3.1), liver volume (≥ 1376 mL; HR: 2.3), and history of prior chemotherapy (≥ 3 lines of treatment; HR: 2.5-2.6) showed an independent survival impact. When follow-up data were included in the analysis, significant factors were maximum diameter of liver metastases (≥ 3.9 cm; HR: 3.1), control of LMBC during follow-up (HR: 0.29), and objective response as best overall response (HR: 0.21). Neither the presence of any extrahepatic metastases nor presence of bone metastases only had a significant survival impact. Median OS was 38.7 vs. 16.1 months in patients with metastases < vs. ≥ 3.9 cm, 36.6 vs. 10.2 months for patients having objective response vs. stable/progressive disease, and 38.5 vs. 14.2 months for patients having controlled vs. non-controlled disease at follow-up.
Mesenchymal stem cells (MSC) are under investigation as a therapy for a variety of disorders. Alt... more Mesenchymal stem cells (MSC) are under investigation as a therapy for a variety of disorders. Although animal models show long term regenerative and immunomodulatory effects of MSC, the fate of MSC after infusion remains to be elucidated. In the present study the localization and viability of MSC was examined by isolation and re-culture of intravenously infused MSC. C57BL/6 MSC (500,000) constitutively expressing DsRed-fluorescent protein and radioactively labeled with Cr-51 were infused via the tail vein in wild-type C57BL/6 mice. After 5 min, 1, 24, or 72 h, mice were sacrificed and blood, lungs, liver, spleen, kidneys, and bone marrow removed. One hour after MSC infusion the majority of Cr-51 was found in the lungs, whereas after 24 h Cr-51 was mainly found in the liver. Tissue cultures demonstrated that viable donor MSC were present in the lungs up to 24 h after infusion, after which they disappeared. No viable MSC were found in the other organs examined at any time. The inducti...
Portal vein embolization (PVE) can be used prior to liver surgery to increase the volume of the r... more Portal vein embolization (PVE) can be used prior to liver surgery to increase the volume of the remaining liver tissue after an extensive resection. However, the application of PVE is limited and new strategies to augment liver regeneration by cellular therapy are promising alternatives. The influence of syngeneic multipotent mesenchymal stromal cells (MSC) on liver regeneration was analysed after the ligation of the right portal vein branches in a porcine model, closely mimicking the situation of human surgery. Liver regeneration was monitored by ultrasonography, immunohistological analysis and serum biochemistry. The volume of the contra-lateral, non-ligated liver lobe increased in all piglets after portal vein ligation. This hyperplasia occurred earlier and was more pronounced in those piglets receiving MSC infusions as compared to non-treated controls. Biochemical liver function was stable in all pigs. Only solitary transplanted MSC were detected in recipient livers two weeks af...
Background Free jejunal interposition is a useful technique for reconstruction of the cervical es... more Background Free jejunal interposition is a useful technique for reconstruction of the cervical esophagus. However, the distal anastomosis between the graft and the remaining thoracic esophagus or a gastric conduit can be technically challenging when located very low in the thoracic aperture. We here describe a modified technique for retrograde stapling of a jejunal graft to a failed gastric conduit using a circular stapler on a delivery system. Case presentation A 56 year-old patient had been referred for esophageal squamous cell carcinoma at 20 cm from the incisors. On day 8 after thoracoabdominal esophagectomy with gastric pull-up, an anastomotic leakage was diagnosed. A proximal-release stent was successfully placed by gastroscopy and the patient was discharged. Two weeks later, an esophagotracheal fistula occurred proximal to the esophageal stent. Cervical esophagostomy was performed with cranial closure of the gastric conduit, which was left in situ within the right hemithorax....
The 4 th expert meeting of the MiSOT (Mesenchymal Stem Cells in Solid Organ Transplantation) Cons... more The 4 th expert meeting of the MiSOT (Mesenchymal Stem Cells in Solid Organ Transplantation) Consortium took place in Barcelona on the 19 th and 20 th of October 2012. This meeting focused on the translation of pre-clinical data into early clinical settings. This position paper highlights the
The immunomodulatory properties of CD8 T cells with regulatory phenotype have become evident. It ... more The immunomodulatory properties of CD8 T cells with regulatory phenotype have become evident. It remains unclear whether the immunomodulatory function of CD8+ CD28-T cells requires antigen-specific TCR interaction with major histocompatibility complex class I (MHC-I). We have isolated naïve CD8+CD28-T suppressor cells (Tsup) from H2-Kk Des-TCR mice that express a transgenic, MHC class I-restricted, clonotypic TCR against an allogeneic MHC class I molecule (H2-Kb) plus self-peptide. These cells were compared to B10.BR wildtype (w/t) CD8+CD28-T cells and to naïve CD4+CD25+ regulatory T cells (Treg) of the same strains. Des CD8 effector T cells proliferated more readily when stimulated by H2-Kb splenocytes than w/t controls, whereas Des CD4 T cells showed the same alloresponse as w/t cells. Activation and proliferation of B10.BR CD4 T cells stimulated by H2-Kb APC was suppressed more effectively by Des CD8+CD28-T cells than by w/t CD8+CD28-T cells. On the contrary, Des CD4+CD25+ T cells inhibited T cell proliferation less effectively than w/t CD4+CD25+ T cells. In conclusion, we demonstrate that the function of naive Tsup is strongly enhanced by antigen recognition. Therefore we expect that Tsup are possible candidates for antigen-specific immunosuppressive therapy.
Background: Shortage of donor organs is one of the major problems for liver transplant programmes... more Background: Shortage of donor organs is one of the major problems for liver transplant programmes. Living liver donation is a possible alternative, which could increase the amount of donor organs available in the short term. Objective: To assess the attitude towards living organ donation in the general population to have an overview of the overall attitude within Germany. Methods: A representative quota of people was evaluated by a mail questionnaire (n = 250). This questionnaire had 24 questions assessing the willingness to be a living liver donor for different potential recipients. Factors for and against living liver donation were assessed. Results: Donating a part of the liver was almost as accepted as donating a kidney. The readiness to donate was highest when participants were asked to donate for children. In an urgent life-threatening situation the will to donate was especially high, whereas it was lower in the case of recipient substance misuse. More women than men expressed a higher disposition to donate for their children. Sex, religion, state of health and age of the donor, however, did not influence other questions on the readiness to consider living organ donation. The will for postmortem organ donation positively correlated with the will to be a living organ donor. Conclusions: The motivation in different demographic subgroups to participate in living liver transplantation is described. Differences in donation readiness resulting from the situation of every donor and recipient are thoroughly outlined. The acceptance for a living liver donation was found to be highand comparable to that of living kidney donation.
Purpose: Inhibitors of heat-shock protein 90 (Hsp90) may interfere with oncogenic signaling pathw... more Purpose: Inhibitors of heat-shock protein 90 (Hsp90) may interfere with oncogenic signaling pathways, including Erk, Akt, and hypoxia-inducible factor-1α (HIF-1α). Because insulin-like growth factor-I receptor (IGF-IR) and signal transducer and activator of transcription 3 (STAT3) signaling pathways are implicated in the progression of pancreatic cancer, we hypothesized that blocking Hsp90 with geldanamycin derivates [17-allylamino-geldanamycin (17-AAG), 17-(dimethylaminoethylamino)-17-demethoxygeldanamycin (17-DMAG)] would impair IGF-I– and interleukin-6–mediated signaling and thus reduce pancreatic tumor growth and angiogenesis in vivo. Experimental Design: Human pancreatic cancer cells (HPAF-II, L3.6pl) were used for experiments. Changes in signaling pathway activation upon Hsp90 blockade were investigated by Western blotting. Effects of Hsp90 inhibition (17-AAG) on vascular endothelial growth factor were determined by ELISA and real-time PCR. Effects of 17-DMAG (25 mg/kg; thrice...
Purpose Pancreatic ductal adenocarcinoma (PDAC) is currently one of the leading causes of cancer ... more Purpose Pancreatic ductal adenocarcinoma (PDAC) is currently one of the leading causes of cancer death worldwide. Therefore, building further subgroups as well as enabling individual patient therapy and diagnostics are needed. X-linked inhibitor of apoptosis protein (XIAP) is known to modulate apoptotic and inflammatory pathways. Its expression was found to correlate with patients’ survival in other tumor entities. This study aims to examine the role of XIAP in patients with PDAC in relation to the inflammatory microenvironment. Methods The PANCALYZE multicenter study group included 257 patients with PDAC. Paraffin-embedded tumor samples were stained immunohistochemically for CD3, CD20, CD38, CD56, CD66b, CD117, and CD163 and XIAP. These stainings were further analyzed digitally with QuPath and survival analyses were done. Results XIAP-positive patients with T-cell, respectively, neutrophil enriched tumors survived significantly longer compared to XIAP-negative patients (CD3: 37.6 v...
(1) Background: IL-17A accelerates pancreatic intraepithelial neoplasia (PanIN) progression. In t... more (1) Background: IL-17A accelerates pancreatic intraepithelial neoplasia (PanIN) progression. In this study, we examined whether IL-17A/IL-17RA promotes pancreatic ductal adenocarcinoma (PDAC) aggressiveness in terms of survival and cancer stem cell modulation. (2) Methods: In vitro, the wound-healing assay, the sphere formation assay, and flow cytometry were applied to assess cancer stem cell features. In vivo, pancreatic tumors were induced in C57BL/6 mice using electroporation with oncogenic plasmids (P53-/-R172H; KrasG12V). Anti-IL-17 antibodies were administered as immunotherapy. We analyzed IL-17A/IL-17RA related survival using publicly available transcriptomic data (n = 903). (3) Results: IL-17A/IL-17RA expression was not related to survival in PDAC patients. IL-17A neither induces stem cell markers nor increases sphere formation and cell motility in vitro. Blocking the IL-17A/IL-17RA axis in a murine pancreatic cancer model did not improve the survival of mice, but reduced the tumor burden slightly. (4) Conclusions: IL-17A does not promote stem cell expansion in PDAC cell lines. Blocking IL-17A/IL-17RA signaling does not interfere with pancreatic cancer development and progression and may not be considered as a promising monotherapy for PDAC.
Pancreatic cancer features elaborate mechanisms of immune evasion. The potential of new immune mo... more Pancreatic cancer features elaborate mechanisms of immune evasion. The potential of new immune molecules was explored to restore the antitumor immune response. If these immune molecules are associated with poor survival, specific drugs could take effect. Here, we analyze the expression of VISTA, LAG3, IDO, and TIM3 on tumor-infiltrating lymphocytes (TILs) and its impact on patient survival. We analyzed 153 pancreatic cancer patients from the prospectively managed database of the multicentered PANCALYZE study. Immunohistochemistry on a tissue microarray assessed VISTA, LAG3, IDO, and TIM3 expression of TILs from the patients undergoing primary resection. Complementarily, we analyzed publicly available transcriptomic data (n = 903). Successful completion of chemotherapy, and lymph node status were independent predictors of survival in the multivariate analysis of the clinicopathologic parameters. Fifteen tumors were exclusively VISTA-positive, thirteen tumors expressed VISTA together ...
In pancreatic ductal adenocarcinoma (PDAC), the tumor stroma constitutes most of the cell mass an... more In pancreatic ductal adenocarcinoma (PDAC), the tumor stroma constitutes most of the cell mass and contributes to therapy resistance and progression. Here we show a hitherto unknown metabolic cooperation between pancreatic stellate cells (PSCs) and tumor cells through Interleukin 17B/Interleukin 17B receptor (IL-17B/IL-17RB) signaling. Tumor-derived IL-17B carrying extracellular vesicles (EVs) activated stromal PSCs and induced the expression of IL-17RB. PSCs increased oxidative phosphorylation while reducing mitochondrial turnover. PSCs activated tumor cells in a feedback loop. Tumor cells subsequently increased oxidative phosphorylation and decreased glycolysis partially via IL-6. In vivo, IL-17RB overexpression in PSCs accelerated tumor growth in a co-injection xenograft mouse model. Our results demonstrate a tumor-to-stroma feedback loop increasing tumor metabolism to accelerate tumor growth under optimal nutritional conditions.
Background To date, patients with metastasized pancreatic ductal adenocarcinoma (PDAC M1) are reg... more Background To date, patients with metastasized pancreatic ductal adenocarcinoma (PDAC M1) are regarded as a uniform collective. We hypothesize the existence of oligometastatic disease (OMD): a state of PDAC M1 disease with better tumor biology, limited metastasis, and increased survival. Methods Data of 128 PDAC M1 patients treated at the University of Cologne between 2008 and 2018 was reviewed. Interdependence between clinical parameter was calculated using the Mann-Whitney U-Test. Survival curves were generated using the Kaplan-Meier method and analyzed using the log-rank test. Results Eighty-one (63%) patients had metastases confined to one organ (single organ metastasis, SOG) whereas the remaining 47 (37%) showed multiple metastatic sites (multi-organ metastasis, MOG). Survival analysis revealed a median overall survival (OS) of 12.2 months for SOG vs 4.5 months for MOG (95% CI 5.7–9.8; p < 0.001). We defined limited disease by the presence of ≤4 metastases in liver or lung. ...
Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers worldwide and effective... more Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers worldwide and effective therapy remains a challenge. IFIT3 is an interferon-stimulated gene with antiviral and pro-inflammatory functions. Our previous work has shown that high expression of IFIT3 is correlated with poor survival in PDAC patients who receive chemotherapy suggesting a link between IFIT3 and chemotherapy resistance in PDAC. However, the exact role and molecular mechanism of IFIT3 in chemotherapy resistance in PDAC has been unclear. Methods: A group of transcriptome datasets were downloaded and analyzed for the characterization of IFIT3 in PDAC. Highly metastatic PDAC cell line L3.6pl and patient-derived primary cell TBO368 were used and IFIT3 knockdown and the corresponding knockin cells were established for in vitro studies. Chemotherapy-induced apoptosis, ROS production, confocal immunofluorescence, subcellular fractionation, chromatin-immunoprecipitation, co-immunoprecipitation and mass spectrometry analysis were determined to further explore the biological role of IFIT3 in chemotherapy resistance of PDAC. Results: Based on PDAC transcriptome data, we show that IFIT3 expression is associated with the squamous molecular subtype of PDAC and an increase in inflammatory response and apoptosis pathways. We further identify a crucial role for IFIT3 in the regulation of mitochondria-associated apoptosis during chemotherapy. Knockdown of IFIT3 attenuates the chemotherapy resistance of PDAC cells to gemcitabine, paclitaxel, and FOLFIRINOX regimen treatments, independent of individual chemotherapy regimens. While IFIT3 overexpression was found to promote drug resistance. Co-immunoprecipitation identified a direct interaction between IFIT3 and the mitochondrial channel protein VDAC2, an important regulator of mitochondria-associated apoptosis. It was subsequently found that IFIT3 regulates the post-translational modification-O-GlcNAcylation of VDAC2 by stabilizing the interaction of VDAC2 with O-GlcNAc transferase. Increased O-GlcNAcylation of VDAC2 protected PDAC cells from chemotherapy induced apoptosis. Conclusions: These results effectively demonstrate a central mechanism by which IFIT3 expression can affect chemotherapy resistance in PDAC. Targeting IFIT3/VDAC2 may represent a novel strategy to sensitize aggressive forms of pancreatic cancer to conventional chemotherapy regimens.
International Journal of Biological Sciences, 2019
Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal malignancies worldwide. PDAC pro... more Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal malignancies worldwide. PDAC prognostic and diagnostic biomarkers are still being explored. The aim of this study is to establish a robust molecular signature that can improve the ability to predict PDAC prognosis. 155 overlapping differentially expressed genes between tumor and non-tumor tissues from three Gene Expression Omnibus (GEO) datasets were explored. A least absolute shrinkage and selection operator method (LASSO) Cox regression model was employed for selecting prognostic genes. We developed a 6-mRNA signature that can distinguish high PDAC risk patients from low risk patients with significant differences in overall survival (OS). We further validated this signature prognostic value in three independent cohorts (GEO batch, P < 0.0001; ICGC, P = 0.0036; Fudan, P = 0.029). Furthermore, we found that our signature remained significant in patients with different histologic grade, TNM stage, locations of tumor entity, age and gender. Multivariate cox regression analysis showed that 6-mRNA signature can be an independent prognostic marker in each of the cohorts. Receiver operating characteristic curve (ROC) analysis also showed that our signature possessed a better predictive role of PDAC prognosis. Moreover, the gene set enrichment analysis (GSEA) analysis showed that several tumorigenesis and metastasis related pathways were indeed associated with higher scores of risk. In conclusion, identifying the 6-mRNA signature could provide a valuable classification method to evaluate clinical prognosis and facilitate personalized treatment for PDAC patients. New therapeutic targets may be developed upon the functional analysis of the classifier genes and their related pathways.
Background: In the present study we review and discuss the current evidence and suggest how to pr... more Background: In the present study we review and discuss the current evidence and suggest how to proceed in the management of oligometastatic disease in upper gastrointestinal cancer. Methods: An electronic search of the PubMed database for relevant articles was performed. Results: Both the search for ‘oligometastasis', ‘oligometastases', ‘oligometastatic', ‘oligometastatic disease' as well as ‘esophageal' and ‘esophageal cancer' and the search for ‘oligometastasis', ‘oligometastases', ‘oligometastatic', ‘oligometastatic disease' as well as ‘gastric', ‘gastric cancer', ‘stomach', and ‘stomach cancer' yielded very few studies. Most data need to be extrapolated in general studies on oligometastatic diseases of different origins. No randomized controlled trial could be found. Conclusion: In the absence of data to formulate recommendations on how to proceed in the treatment of oligometastatic disease in upper gastrointestinal cancer,...
Cancer stem cells (CSCs) have been identified as a subpopulation of stem-like cancer cells with t... more Cancer stem cells (CSCs) have been identified as a subpopulation of stem-like cancer cells with the ability of self-renewal and differentiation in hematological malignancies and solid tumors. Pancreatic cancer is one of the most lethal cancers worldwide. CSCs are thought to be responsible for cancer initiation, progression, metastasis, chemoresistance, and recurrence in pancreatic cancer. In this review, we summarize the characteristics of pancreatic CSCs and discuss the mechanisms involved in resistance to chemotherapy, the interactions with the niche, and the potential role in cancer immunoediting. We propose that immunotherapy targeting pancreatic CSCs, in combination with targeting the niche components, may provide a novel treatment strategy to eradicate pancreatic CSCs and hence improve outcomes in pancreatic cancer.
Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies today with an urge... more Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies today with an urgent need for novel therapeutic strategies. Biomarker analysis helps to better understand tumor biology and might emerge as a tool to develop personalized therapies. The aim of the study is to investigate four promising biomarkers to predict the clinical course and particularly the pattern of tumor recurrence after surgical resection. Patients undergoing surgery for PDAC can be enrolled into the PANCALYZE trial. Biomarker expression of CXCR4, SMAD4, SOX9 and IFIT3 will be prospectively assessed by immunohistochemistry and verified by rt.-PCR from tumor and adjacent healthy pancreatic tissue of surgical specimen. Immunohistochemistry expression pattern of all four biomarkers will be combined into a single score. Beginning with the hospital stay clinical data from enrolled patients will be collected and followed. Different adjuvant chemotherapy protocols will be used to create subgroups. The...
Background: Liver metastases from breast cancer (LMBC) are typically considered to indicate syste... more Background: Liver metastases from breast cancer (LMBC) are typically considered to indicate systemic disease spread and patients are most often offered systemic palliative treatment only. However, retrospective studies suggest that some patients may have improved survival with local treatment of their liver metastases compared to systemic therapy alone. In the absence of randomized trials, it is important to identify patient characteristics indicating that benefit from local treatment can be expected. Methods: 59 patients undergoing radiofrequency ablation (RFA), interstitial brachytherapy (BT), or radioembolization (RE) of LMBC as a salvage treatment were studied. Potential factors influencing survival were analyzed in a multivariate Cox model. For factors identified to have an independent survival impact, Kaplan-Meier analysis and comparison of overall survival (OS) using the log-rank test was performed. Results: Median OS following local interventional treatment was 21.9 months. Considering only factors evaluable at treatment initiation, maximum diameter of liver metastases (≥3.9 cm; HR: 3.1), liver volume (≥ 1376 mL; HR: 2.3), and history of prior chemotherapy (≥ 3 lines of treatment; HR: 2.5-2.6) showed an independent survival impact. When follow-up data were included in the analysis, significant factors were maximum diameter of liver metastases (≥ 3.9 cm; HR: 3.1), control of LMBC during follow-up (HR: 0.29), and objective response as best overall response (HR: 0.21). Neither the presence of any extrahepatic metastases nor presence of bone metastases only had a significant survival impact. Median OS was 38.7 vs. 16.1 months in patients with metastases < vs. ≥ 3.9 cm, 36.6 vs. 10.2 months for patients having objective response vs. stable/progressive disease, and 38.5 vs. 14.2 months for patients having controlled vs. non-controlled disease at follow-up.
Mesenchymal stem cells (MSC) are under investigation as a therapy for a variety of disorders. Alt... more Mesenchymal stem cells (MSC) are under investigation as a therapy for a variety of disorders. Although animal models show long term regenerative and immunomodulatory effects of MSC, the fate of MSC after infusion remains to be elucidated. In the present study the localization and viability of MSC was examined by isolation and re-culture of intravenously infused MSC. C57BL/6 MSC (500,000) constitutively expressing DsRed-fluorescent protein and radioactively labeled with Cr-51 were infused via the tail vein in wild-type C57BL/6 mice. After 5 min, 1, 24, or 72 h, mice were sacrificed and blood, lungs, liver, spleen, kidneys, and bone marrow removed. One hour after MSC infusion the majority of Cr-51 was found in the lungs, whereas after 24 h Cr-51 was mainly found in the liver. Tissue cultures demonstrated that viable donor MSC were present in the lungs up to 24 h after infusion, after which they disappeared. No viable MSC were found in the other organs examined at any time. The inducti...
Portal vein embolization (PVE) can be used prior to liver surgery to increase the volume of the r... more Portal vein embolization (PVE) can be used prior to liver surgery to increase the volume of the remaining liver tissue after an extensive resection. However, the application of PVE is limited and new strategies to augment liver regeneration by cellular therapy are promising alternatives. The influence of syngeneic multipotent mesenchymal stromal cells (MSC) on liver regeneration was analysed after the ligation of the right portal vein branches in a porcine model, closely mimicking the situation of human surgery. Liver regeneration was monitored by ultrasonography, immunohistological analysis and serum biochemistry. The volume of the contra-lateral, non-ligated liver lobe increased in all piglets after portal vein ligation. This hyperplasia occurred earlier and was more pronounced in those piglets receiving MSC infusions as compared to non-treated controls. Biochemical liver function was stable in all pigs. Only solitary transplanted MSC were detected in recipient livers two weeks af...
Background Free jejunal interposition is a useful technique for reconstruction of the cervical es... more Background Free jejunal interposition is a useful technique for reconstruction of the cervical esophagus. However, the distal anastomosis between the graft and the remaining thoracic esophagus or a gastric conduit can be technically challenging when located very low in the thoracic aperture. We here describe a modified technique for retrograde stapling of a jejunal graft to a failed gastric conduit using a circular stapler on a delivery system. Case presentation A 56 year-old patient had been referred for esophageal squamous cell carcinoma at 20 cm from the incisors. On day 8 after thoracoabdominal esophagectomy with gastric pull-up, an anastomotic leakage was diagnosed. A proximal-release stent was successfully placed by gastroscopy and the patient was discharged. Two weeks later, an esophagotracheal fistula occurred proximal to the esophageal stent. Cervical esophagostomy was performed with cranial closure of the gastric conduit, which was left in situ within the right hemithorax....
The 4 th expert meeting of the MiSOT (Mesenchymal Stem Cells in Solid Organ Transplantation) Cons... more The 4 th expert meeting of the MiSOT (Mesenchymal Stem Cells in Solid Organ Transplantation) Consortium took place in Barcelona on the 19 th and 20 th of October 2012. This meeting focused on the translation of pre-clinical data into early clinical settings. This position paper highlights the
The immunomodulatory properties of CD8 T cells with regulatory phenotype have become evident. It ... more The immunomodulatory properties of CD8 T cells with regulatory phenotype have become evident. It remains unclear whether the immunomodulatory function of CD8+ CD28-T cells requires antigen-specific TCR interaction with major histocompatibility complex class I (MHC-I). We have isolated naïve CD8+CD28-T suppressor cells (Tsup) from H2-Kk Des-TCR mice that express a transgenic, MHC class I-restricted, clonotypic TCR against an allogeneic MHC class I molecule (H2-Kb) plus self-peptide. These cells were compared to B10.BR wildtype (w/t) CD8+CD28-T cells and to naïve CD4+CD25+ regulatory T cells (Treg) of the same strains. Des CD8 effector T cells proliferated more readily when stimulated by H2-Kb splenocytes than w/t controls, whereas Des CD4 T cells showed the same alloresponse as w/t cells. Activation and proliferation of B10.BR CD4 T cells stimulated by H2-Kb APC was suppressed more effectively by Des CD8+CD28-T cells than by w/t CD8+CD28-T cells. On the contrary, Des CD4+CD25+ T cells inhibited T cell proliferation less effectively than w/t CD4+CD25+ T cells. In conclusion, we demonstrate that the function of naive Tsup is strongly enhanced by antigen recognition. Therefore we expect that Tsup are possible candidates for antigen-specific immunosuppressive therapy.
Background: Shortage of donor organs is one of the major problems for liver transplant programmes... more Background: Shortage of donor organs is one of the major problems for liver transplant programmes. Living liver donation is a possible alternative, which could increase the amount of donor organs available in the short term. Objective: To assess the attitude towards living organ donation in the general population to have an overview of the overall attitude within Germany. Methods: A representative quota of people was evaluated by a mail questionnaire (n = 250). This questionnaire had 24 questions assessing the willingness to be a living liver donor for different potential recipients. Factors for and against living liver donation were assessed. Results: Donating a part of the liver was almost as accepted as donating a kidney. The readiness to donate was highest when participants were asked to donate for children. In an urgent life-threatening situation the will to donate was especially high, whereas it was lower in the case of recipient substance misuse. More women than men expressed a higher disposition to donate for their children. Sex, religion, state of health and age of the donor, however, did not influence other questions on the readiness to consider living organ donation. The will for postmortem organ donation positively correlated with the will to be a living organ donor. Conclusions: The motivation in different demographic subgroups to participate in living liver transplantation is described. Differences in donation readiness resulting from the situation of every donor and recipient are thoroughly outlined. The acceptance for a living liver donation was found to be highand comparable to that of living kidney donation.
Purpose: Inhibitors of heat-shock protein 90 (Hsp90) may interfere with oncogenic signaling pathw... more Purpose: Inhibitors of heat-shock protein 90 (Hsp90) may interfere with oncogenic signaling pathways, including Erk, Akt, and hypoxia-inducible factor-1α (HIF-1α). Because insulin-like growth factor-I receptor (IGF-IR) and signal transducer and activator of transcription 3 (STAT3) signaling pathways are implicated in the progression of pancreatic cancer, we hypothesized that blocking Hsp90 with geldanamycin derivates [17-allylamino-geldanamycin (17-AAG), 17-(dimethylaminoethylamino)-17-demethoxygeldanamycin (17-DMAG)] would impair IGF-I– and interleukin-6–mediated signaling and thus reduce pancreatic tumor growth and angiogenesis in vivo. Experimental Design: Human pancreatic cancer cells (HPAF-II, L3.6pl) were used for experiments. Changes in signaling pathway activation upon Hsp90 blockade were investigated by Western blotting. Effects of Hsp90 inhibition (17-AAG) on vascular endothelial growth factor were determined by ELISA and real-time PCR. Effects of 17-DMAG (25 mg/kg; thrice...
Uploads
Papers by Felix Popp