Andrej Wagner

Temoporfin improves efficacy of photodynamic therapy in advanced biliary tract carcinoma: A multicenter prospective phase II study

Photodynamic therapy using porfimer (P‐PDT) improves palliation and survival in nonresectable hilar bile duct cancer. Tumoricidal penetration depth of temoporfin‐PDT (T‐PDT) is twice that of P‐PDT. In a single‐arm phase II study we investigated the safety, efficacy, survival time, and adverse events of T‐PDT compared with previous data on P‐PDT. Twenty‐nine patients (median 71 [range 47‐88] years) with nonresectable hilar bile duct cancer were treated with T‐PDT (median 1 [range 1‐4] sessions) plus stenting and followed up every 3 months. The PDT was well tolerated. In patients with occluded segments at baseline (n = 28) a reopening of a median of 3 (range 1‐7) segments could be achieved: n = 16 local response and n = 11 stable local disease, one progressive disease. Cholestasis and performance significantly improved when impaired at baseline. Time to local tumor progression was a median of 6.5 (2.7‐41.0) months. Overall survival time was a median of 15.4 (range 4.4‐62.4) months. Patients died from tumor progression (55%), cholangitis (18%), pneumonia (7%), hemobilia (7%), esophagus variceal hemorrhage (3%), and vascular diseases (10%). Adverse events were cholangitis (n = 4), liver abscess (n = 2), cholecystitis (n = 2), phototoxic skin (n = 5), and injection site reactions (n = 7). Compared to previous P‐PDT, T‐PDT shows prolonged time to local tumor progression (median 6.5 versus 4.3 months, P < 0.01), fewer PDT treatments needed (median 1 versus 3, P < 0.01), a higher 6‐month survival rate (83% versus 70%, P < 0.01), and a trend for longer overall median survival (15.4 versus 9.3 months, P = 0.72) yet not significantly different. The risk of adverse events is not increased except for (avoidable) subcutaneous phototoxicity at the injection site. Conclusion: Temoporfin‐PDT can safely be delivered to hilar bile duct cancer patients and results in prolonged patency of hilar bile ducts, a trend for longer survival time, and similar palliation as with P‐PDT. (Hepatology 2015;62:1456–1465)

The BMI1 inhibitor PTC-209 is a potential compound to halt cellular growth in biliary tract cancer cells

BMI1 is a core component of the polycomb repressive complex 1 (PRC1) and is up-regulated in biliary tract cancer (BTC), contributing to aggressive clinical features. In this study we investigated the cytotoxic effects of PTC-209, a recently developed inhibitor of BMI1, in BTC cells. PTC-209 reduced overall viability in BTC cell lines in a dose-dependent fashion (0.04 - 20 μM). Treatment with PTC-209 led to slightly enhanced caspase activity and stop of cell proliferation. Cell cycle analysis revealed that PTC-209 caused cell cycle arrest at the G1/S checkpoint. A comprehensive investigation of expression changes of cell cycle-related genes showed that PTC-209 caused significant down-regulation of cell cycle-promoting genes as well as of genes that contribute to DNA synthesis initiation and DNA repair, respectively. This was accompanied by significantly elevated mRNA levels of cell cycle inhibitors. In addition, PTC-209 reduced sphere formation and, in a cell line-dependent manner, aldehyde dehydrogease-1 positive cells. We conclude that PTC-209 might be a promising drug for future in vitro and in vivo studies in BTC.

Untutored Learning Curve to Establish Endoscopic Submucosal Dissection on Competence Level

Backgrounds/Aims: Endoscopic submucosal dissection (ESD) of early cancer allows precise staging and avoids recurrence or surgery. Tutored by experts, ESD has rapidly spread in Japan, but still demands untutored learning in Western countries. A step-up approach starts with easiest gastric neoplasias, but fails on their low prevalence in Western countries. A prevalence-based approach includes challenging colonic neoplasias. Methods: We analyzed an untutored series of initial 50 ESD procedures by an experienced endoscopist on consecutive lesions referred according to prevalence. Results: Overall, 48 lesions (20% upper gastrointestinal, 80% colorectal; 2 hyperplastic (inflammatory) lesions, 46 neoplasms) were completely resected intention-to-treat with ESD, 2 required a second ESD. Neoplasias were resected 76% en-bloc (46% ESD, 30% ESD with snaring), 17% by ESD with snaring in 2-3 pieces, and 6.5% as ESD with snaring in multiple pieces. None of 15 neoplasias with high-grade intraepithelial neoplasia or an early esophageal cancer (R0) had recurred. Complications were 2 bleedings (4%) and 7 perforations (14%), 5 clipped and 2 (4%) operated. All patients were discharged within 9 days without long-term morbidity. Conclusion:Untutored learning of ESD is feasible on colonic lesions. We propose to establish ESD in Europe with structured training and a prevalence-of-lesions-based approach.

The role of polycomb repressive complexes in biliary tract cancer.

Introduction: Polycomb group proteins are major epigenetic regulators that modify histone tails. They are organized in two multi-protein complexes called polycomb repressive complex (PRC) 1 and 2. Aberrant PRC activity is known to contribute to the development and aggressiveness of many cancers. Biliary tract cancer (BTC) is a rare malignancy associated with high chemoresistance and poor clinical outcome. Here we review the role of the PRC complexes and the effects of RNAi and drug-mediated inhibition of PRC1 and PRC2 in BTC. Areas covered: This review gives a short overview of the composition, biochemical functions and oncogenic role of PRC complexes. We then focus on and summarize the results of current studies that address the role of PRC in BTC. Finally, we discuss options and results of therapeutic targeting of PRC in BTC. Expert opinion: Pharmacological inhibition of the two PRC complexes seems to be a promising strategy for treatment of BTC. To date, only few studies have addressed the therapeutic effect of PRC inhibition in BTC. Therefore, it will be important to test established PRC inhibitors, such as DZNep, as well as newly developed drugs, for example, PTC209, to gain more insight into the role of the PRC complexes in BTC and potentially to develop new therapeutic strategies.

Deregulated MicroRNAs in Biliary Tract Cancer: Functional Targets and Potential Biomarkers

Biliary tract cancer (BTC) is still a fatal disease with very poor prognosis. The lack of reliable biomarkers for early diagnosis and of effective therapeutic targets is a major demanding problem in diagnosis and management of BTC. Due to the clinically silent and asymptomatic characteristics of the tumor, most patients are diagnosed at an already advanced stage allowing only for a palliative therapeutic approach. MicroRNAs are small noncoding RNAs well known to regulate various cellular functions and pathologic events including the formation and progression of cancer. Over the last years, several studies have shed light on the role of microRNAs in BTC, making them potentially attractive therapeutic targets and candidates as biomarkers. In this review, we will focus on the role of oncogenic and tumor suppressor microRNAs and their direct targets in BTC. Furthermore, we summarize and discuss data that evaluate the diagnostic power of deregulated microRNAs as possible future biomarkers for BTC.

MicroRNAs Associated with the Efficacy of Photodynamic Therapy in Biliary Tract Cancer Cell Lines

Photodynamic therapy (PDT) is a palliative treatment option for unresectable hilar biliary tract cancer (BTC) showing a considerable benefit for survival and quality of life with few side effects. Currently, factors determining the cellular response of BTC cells towards PDT are unknown. Due to their multifaceted nature, microRNAs (miRs) are a promising analyte to investigate the cellular mechanisms following PDT. For two photosensitizers, Photofrin® and Foscan®, the phototoxicity was investigated in eight BTC cell lines. Each cell line (untreated) was profiled for expression of n = 754 miRs using TaqMan® Array Human MicroRNA Cards. Statistical analysis and bioinformatic tools were used to identify miRs associated with PDT efficiency and their putative targets, respectively. Twenty miRs correlated significantly with either high or low PDT efficiency. PDT was particularly effective in cells with high levels of clustered miRs 25-93*-106b and (in case of miR-106b) a phenotype characterized by high expression of the mesenchymal marker vimentin and high proliferation (cyclinD1 and Ki67 expression). Insensitivity towards PDT was associated with high miR-200 family expression and (for miR-cluster 200a/b-429) expression of differentiation markers Ck19 and Ck8/18. Predicted and validated downstream targets indicate plausible involvement of miRs 20a*, 25, 93*, 130a, 141, 200a, 200c and 203 in response mechanisms to PDT, suggesting that targeting these miRs could improve susceptibility to PDT in insensitive cell lines. Taken together, the miRNome pattern may provide a novel tool for predicting the efficiency of PDT and—following appropriate functional verification—may subsequently allow for optimization of the PDT protocol.

Relevance of MicroRNA200 Family and MicroRNA205 for Epithelial to Mesenchymal Transition and Clinical Outcome in Biliary Tract Cancer Patients

Extensive stromal interaction is one reason for the dismal outcome of biliary tract cancer (BTC) patients. Epithelial to mesenchymal transition (EMT) is involved in tumor invasion and metastasis and is partly regulated by microRNAs (miRs). This study explores the expression of anti-EMT miR200 family (miR141, −200a/b/c, −429) and miR205 as well as the EMT-related proteins E-cadherin and vimentin in a panel of BTC cell lines and clinical specimens by quantitative real-time polymerase chain reaction, Western blot and immunohistochemistry, respectively. MicroRNA expression was correlated to (i) the expression patterns of E-cadherin and vimentin; (ii) clinicopathological characteristics; and (iii) survival data. MicroRNA-200 family and miR205 were expressed in all BTC cells and clinical specimens. E-cadherin and vimentin showed a mutually exclusive expression pattern in both, in vitro and in vivo. Expression of miR200 family members positively correlated with E-cadherin and negatively with vimentin expression in BTC cells and specimens. High expression of miR200 family members (but not miR205) and E-cadherin was associated with longer survival, while low miR200 family and high vimentin expression was a predictor of unfavorable survival. Overall, the current study demonstrates the relevance of the miR200 family in EMT of BTC tumors and suggests these miRs as predictors for positive outcome.

Cytotoxic effects of chemokine receptor 4 inhibition by AMD3100 in biliary tract cancer cells: Potential drug synergism with gemcitabine

Biliary tract cancer (BTC) remains one of the most life-threatening types of cancer due to the lack of efficient therapies. Advanced tumour stages at the point of diagnosis and high chemoresistance are two of the predominant reasons for a 5-year survival rate of only ~5%. The present study investigated the effect of the chemokine receptor 4 (CXCR4) inhibitor AMD3100 (Plerixafor), alone and in combination with standard gemcitabine chemotherapy, on the proliferation of BTC cells. The expression of CXCR4 was analysed by reverse transcription-quantitative polymerase chain reaction in eight heterogeneously differentiated BTC cell lines. The effects of treatment with the CXCR4 antagonist, AMD3100, on cell viability and anchorage-independent growth, and the possible synergistic cytotoxic effects of AMD3100 with standard chemotherapeutics were assessed. The expression of CXCR4 was observed to a variable extent in all eight BTC cell lines, with SkChA-1 cells exhibiting the highest expression levels. Treatment with AMD3100 led to a marginal decrease in cell viability in the cell lines, with the exception of the CCSW-1 cells, and a significant reduction in the GBC, MzChA-1, SkChA.-1 and TFK-1 cell lines. The combined treatment of the SkChA-1 cells with varying concentrations of AMD3100 and standard gemcitabine chemotherapy revealed a more marked overall cytotoxicity, indicating a potential synergistic effect. In addition, AMD3100 significantly reduced anchorage-independent growth in the SkChA-1 cells. Overall, the results of the present study suggest that the inhibition of CXCR4 by AMD3100, in combination with gemcitabine, may be a suitable strategy for the future therapy of BTC.

Neoadjuvant Down-Sizing of Hilar Cholangiocarcinoma with Photodynamic Therapy—Long-Term Outcome of a Phase II Pilot Study :

Hilar cholangiocarcinoma (CC) is non-resectable in the majority of patients often due to intrahepatic extension along bile duct branches/segments, and even after complete resection (R0) recurrence can be as high as 70%. Photodynamic therapy (PDT) is an established palliative local tumor ablative treatment for non-resectable hilar CC. We report the long-term outcome of curative resection (R0) performed after neoadjuvant PDT for downsizing of tumor margins in seven patients (median age 59 years) with initially non-resectable hilar CC. Photofrin® was injected intravenously 24–48 h before laser light irradiation of the tumor stenoses and the adjacent bile duct segments. Major resective surgery was done with curative intention six weeks after PDT. All seven patients had been curatively (R0) resected and there were no undue early or late complications for the neoadjuvant PDT and surgery. Six of seven patients died from tumor recurrence at a median of 3.2 years after resection, the five-year survival rate was 43%. These results are comparable with published data for patients resected R0 without pre-treatment, indicating that neoadjuvant PDT is feasible and could improve overall survival of patients considered non-curatively resectable because of initial tumor extension in bile duct branches/segments—however, this concept needs to be validated in a larger trial.

Reduced complication rates of percutaneous transhepatic biliary drainage with ultrasound guidance

We aimed to analyze the benefits of adding ultrasound (US) guidance to the standard fluoroscopically assisted percutaneous transhepatic biliary drainage (F‐PTBD). We also performed a systematic literature review of success and complication rates of US‐PTBD in a wide field of indications.