Sebastian Belle

Circulating endothelial progenitor cells are increased in human lung cancer and correlate with stage of disease

AIM Recent studies suggest that circulating endothelial progenitor cells (cEPCs) are recruited to the angiogenic vascular system of non-small-cell lung cancer (NSCLC) and correlate with clinical behaviour. Consequently, the level of cEPCs has been proposed as a novel biomarker for disease progression in NSCLC. The role of cEPCs for the vascularisation of small-cell lung cancer (SCLC) is still unknown. Therefore, this study aims to examine the level of cEPCs as well as the level of EPC mobilising mediators in the blood of lung cancer patients and the correlation with tumour stage and disease progression. METHODS In this study, 36 patients with biopsy-proven lung cancer (32 NSCLC, 4 SCLC) and 15 healthy individuals were recruited. Peripheral blood mononuclear cells (PBMCs) were isolated by Ficoll density gradient centrifugation, and cEPCs were characterised by triple staining using antibodies against CD133, CD34 and vascular endothelial growth factor-receptor (VEGFR)-2. Serum concentrations of VEGF were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS In lung cancer patients, the number of cEPCs was significantly higher than in healthy controls (p=0.000). Regarding tumour stage, NSCLC patients with UICC III-IV had significantly higher EPC counts than UICC I-IIB patients (p=0.044). Serum VEGF concentrations in lung cancer patients were significantly higher than in healthy controls (p=0.000) and correlated with cEPC numbers for all the groups (r=0.42, p=0.003). Follow-up data (n=20) revealed significantly higher cEPC numbers in lung cancer patients with tumour progression than in patients without evidence or progression of disease. The relative change in cEPC numbers between pre- and post-treatment assessment was significantly correlated to disease progression (p=0.000, log rank test) and the combined end points of progression and/or death (p=0.003, log rank test). CONCLUSION Our results show increased cEPCs numbers in lung cancer patients, which may play a role in the vascularisation of lung cancer. Moreover, our results suggest an association of cEPC numbers with tumour stage and progression.

Melan-A/MART1 Analog Peptide Triggers Anti-myeloma T-cells Through Crossreactivity With HM1.24

The Melan-Aaa26–35 (EAAGIGILTV) peptide is a human leukocyte antigen (HLA)-A2-restricted T-cell epitope within the Melan-A/MART-1 tumor antigen expressed on malignant melanoma cells. Melan-A and Melan-A analog (ELAGIGILTV, Melan-Aaa26–35*A27L) specific T-cells can be expanded reliably for immunotherapeutic approaches in vitro. We studied the ability of Melan-A analog (ELAGIGILTV, Melan-Aaa26–35*A27L) specific T-cells to recognize the HM1.24aa22−30 (LLLGIGILV) peptide within the HM1.24 antigen presented by normal and malignant plasma cells. Peripheral blood mononuclear cells from HLA-A2+ healthy donors and HLA-A2+ multiple myeloma (MM) patients were stimulated with Melan-A analog peptide-loaded autologous dendritic cells, and expanded in vitro. T-cell activation was assessed by interferon-γ specific enzyme-linked immunosorbent spot and cytotoxicity by 51Chromium-release-assays. The frequency of Melan-A analog specific CD8+ T-cells was detected by using tetramers. Melan-A analog specific T-cells from HLA-A2+ healthy donors and HLA-A2+ MM patients showed a interferon-γ secretion mediated by HM1.24aa22−30 peptide-pulsed T2 cells and lysed the HLA-A2+ HM1.24+ U266 and XG-1 human myeloma derived cell-lines as well as the B-lymphoblastoid cell-line IM-9. Melan-A analog specific T-cells from MM patients specifically lysed autologous MM cells. The current data demonstrate that Melan-A analog specific T-cells crossreact with HM1.24aa22−30. They might be a tool for the future use in immunotherapy against MM.

Identification of HLA‐A2 restricted T‐cell epitopes within the conserved region of the immunoglobulin G heavy‐chain in patients with multiple myeloma

Objective:  The aim of this study is the identification of HLA‐A2 restricted T‐cell epitopes in the conserved region of the immunoglobulin‐G‐heavy‐chain (IgGH) that can be used for immunotherapy in multiple myeloma (MM) patients.

Risk Factors for Local Recurrence of Large, Flat Colorectal Polyps after Endoscopic Mucosal Resection

Aims: Removal of large, flat colorectal polyps by endoscopic mucosal resection (EMR) is effective, but local recurrences occur regularly. This study investigated risk factors for local recurrence. Method: Cases of EMR of flat colorectal polyps ≥20 mm at an academic center from 2004 to 2011 were retrospectively analyzed for polyp features, resection technique, complications and local recurrences. Behavioral risk factors were retrospectively determined by self-administered questionnaires. Results: Data were collected for 129 patients (57.3% male, mean age at time of EMR: 65.0 years). Mean polyp size was 37.2 mm. Polyps were mostly adenoma with low-grade dysplasia (58.1%) and predominantly located in the right colon (62%). En bloc resection was performed in 31.8%. The median follow-up time was 40 months. Local recurrence occurred in 26.3% of patients, with 87% being recurrence-free after 1 year (95% CI 81-93%). A history of smoking was reported by 51.6% of patients and 88.4% reported regular alcohol consumption. Univariate analysis showed that polyp size and piecemeal resection were associated with risk of local recurrence. In multivariate analysis, only polyp size was predictive for local recurrence. No association was found for behavioral risk factors. Conclusion: Polyp size is the main predictor of local recurrence after EMR of large, flat colorectal polyps.

Phase I study of imatinib, cisplatin and 5-fluoruracil or capecitabine in advanced esophageal and gastric adenocarcinoma

BackgroundDespite all benefit provided by established therapies prognosis of gastric cancer remains poor. Targeted inhibition of platelet derived growth factor receptor (PDGFR) by imatinib may influence tumor growth and amplify chemotherapeutic effects.MethodsThis phase I study evaluated dose limiting toxicity (DLT) of imatinib combinated with chemotherapy according to a 3-patient cohort dose-escalating design. Thirty-five patients received cisplatin (60 mg/m2 d1 q 3w)/ capecitabine (1250 mg/m2 bid d1-14 q 21) or cisplatin (50 mg/m2 d1 q 2w)/ 5-fluoruracil (2 g/m2 d1, q 1w). Imatinib was started d - 4 with dose escalation from 300 to 700 mg QD in 100 mg steps.ResultsAt imatinib dose level 1 (300mg) one DLT was observed, three more patients were enrolled without further DLT. At dose level 5 (700 mg) two gastric perforations occurred, so 600 mg imatinib emerged as the maximum tolerated dose. Major grade 3/4 toxicities were nausea (6%), anemia (6%) and fatigue (3%). Response evaluation revealed partial response in 27% and stable disease in 43% of the assessable patients.ConclusionsCombination of imatinib and chemotherapy is well tolerated. Response rates were not superior to those of standard therapy. Further investigations of a larger group of patients are required to confirm the amplification of chemotherapy effects by imatinib.Trial registrationEuropean Clinical Trials Database: Eudra-CT2006-005792-17 and Clinical Trials Database: NCT00601510

Invitation letters increase participation in colorectal cancer screening – results from an observational study

Background and Aim Participation rates in the German colorectal cancer screening program are low. Starting in 2013, a large health insurance plan in Bavaria, Germany, is sending an additional invitation letter to insured individuals when they turn 50 or 55 years and become eligible for participation in the program. The letter provides detailed information on colorectal cancer screening. We assessed the impact of the invitation letter on utilization rates. Methods Insurance claims data of a total of 48 343 individuals who had turned 50 or 55 years between 2012 to 2014 were reviewed for utilization rates of screening colonoscopy and fecal blood tests. Utilization rates 1 year prior (2012) and 2 years after introduction of the invitation letter (2013 and 2014) were compared. Furthermore, providers of colorectal cancer screening were determined. Results Within 6 months after turning 50 or 55 years, 8.8 - 10.2 % of all insured individuals participated in colorectal cancer screening, with the majority being females. After the introduction of the invitation letter, a moderate increase in participation rates could be observed (increase to 109 % [RR 101.7 - 117.3 %, p = 0.02] in 2014). The uptake rate of screening colonoscopy was significantly higher in recipients of the letter (increase to 138.4 % [RR 110.4 - 173.8 %, p = 0.0043] in 2013 and to 149 % [RR 119.5 - 186.3 %, p = 0.0003] in 2014). Furthermore, a significantly higher proportion of general practitioners and gastroenterologists provided colorectal cancer screening in individuals receiving the invitation letter. Conclusions Introduction of an invitation letter can improve participation rates for colorectal cancer screening.

Outcome of Colorectal Cancer Patients Treated with Combination Bevacizumab Therapy: A Pooled Retrospective Analysis of Three European Cohorts from the Angiopredict Initiative

Background/Aims: This study is aimed at analyzing the survival rates and prognostic factors of stage IV colorectal cancer patients from 3 European cohorts undergoing combination chemotherapy with bevacizumab. Methods: Progression free-survival (PFS) and overall survival (OS) were analyzed in 172 patients using the Kaplan-Meier method and uni- and multivariable Cox proportional hazards regression models. Results: The median PFS was 9.7 and the median OS 27.4 months. Patients treated at centers in Germany (n = 97), Ireland (n = 32), and The Netherlands (n = 43) showed a median PFS of 9.9, 9.2, and 9.7 months, OS of 34.0, 20.5, and 25.1 months, respectively. Patients >65 years had a significantly shorter PFS (9.5 vs. 9.8 months) but not OS (27.4 vs. 27.5 months) than younger patients. High tumor grade (G3/4) was associated with a shorter PFS, T4 classification with both shorter PFS and OS. Fluoropyrimidine (FP) chemotherapy backbones (doublets and single) had comparable outcomes, while patients not receiving FP backbones had a shorter PFS. In multivariable analysis, age and non-FP backbone were associated with inferior PFS, T4 classification and therapy line >2nd were significantly associated with poor PFS and OS. Conclusion: The observed survival rates confirm previous studies and demonstrate reproducible benefits of combination bevacizumab regimens. Classification T4, non-FP chemotherapy backbone, and age >65 were associated with inferior outcome.

Single-cell genetic analysis of clonal dynamics in colorectal adenomas indicates CDX2 gain as a predictor of recurrence: Clonal dynamics and genetic predictors for colorectal adenoma recurrence

Colorectal adenomas are common precancerous lesions with the potential for malignant transformation to colorectal adenocarcinoma. Endoscopic polypectomy provides an opportunity for cancer prevention; however, recurrence rates are high. We collected formalin‐fixed paraffin‐embedded tissue of 15 primary adenomas with recurrence, 15 adenomas without recurrence, and 14 matched pair samples (primary adenoma and the corresponding recurrent adenoma). The samples were analysed by array‐comparative genomic hybridisation (aCGH) and single‐cell multiplex interphase fluorescence in situ hybridisation (miFISH) to understand clonal evolution, to examine the dynamics of copy number alterations (CNAs) and to identify molecular markers for recurrence prediction. The miFISH probe panel consisted of 14 colorectal carcinogenesis‐relevant genes (COX2, PIK3CA, APC, CLIC1, EGFR, MYC, CCND1, CDX2, CDH1, TP53, HER2, SMAD7, SMAD4 and ZNF217), and a centromere probe (CEP10). The aCGH analysis confirmed the genetic landscape typical for colorectal tumorigenesis, that is, CNAs of chromosomes 7, 13q, 18 and 20q. Focal aberrations (≤10 Mbp) were mapped to chromosome bands 6p22.1‐p21.33 (33.3%), 7q22.1 (31.4%) and 16q21 (29.4%). MiFISH detected gains of EGFR (23.6%), CDX2 (21.8%) and ZNF217 (18.2%). Most adenomas exhibited a major clone population which was accompanied by multiple smaller clone populations. Gains of CDX2 were exclusively seen in primary adenomas with recurrence (25%) compared to primary adenomas without recurrence (0%). Generation of phylogenetic trees for matched pair samples revealed four distinct patterns of clonal dynamics. In conclusion, adenoma development and recurrence are complex genetic processes driven by multiple CNAs whose evaluations by miFISH, with emphasis on CDX2, might serve as a predictor of recurrence.

Submucosal injection with waterjet improves endoscopic mucosal resection of colorectal adenoma – a randomised controlled clinical trial

Abstract Purpose: Endoscopic mucosal resection (EMR) of colorectal adenomas leads to a reduced incidence of, and mortality from, colorectal carcinoma. Large adenomas are especially difficult to resect. Submucosal injection is a key part of EMR, as it allows for complete resection and decreased complications. We previously demonstrated in both animal models and a clinical trial that a focussed fluid beam applied to the mucosa creates selective fluid cushions in the submucosa selective tissue elevation by pressure (STEP). In this study, we examined the potential of this new technique compared to the standard inject and cut technique. Methods: This was a monocentric prospective two armed randomised controlled clinical trial comparing the STEP technique to the standard needle injection. We included patients with Yamada I and II adenomas ≥12 mm. Results: One hundred fifty-five patients were treated in the trial. With the STEP technique there was a significantly higher rate of en-bloc resection, whereas piecemeal resection was more common in the standard arm. The odds ratio of piecemeal resection was 2.422 with a 95% confidence interval of 1.163–5.045 (p value .0195). There was no significant difference in resection time between the two techniques, while there was a significant difference in resections speed for the STEP technique. There was also no difference in complication rates. Conclusions: This study demonstrated that the new STEP technique leads to a higher rate of en-bloc resections than the standard injection technique in endoscopic mucosa resection of colorectal adenomas. The STEP technique can play an important role in the future of EMR.

Epigenetic silencing of tumor suppressor candidate 3 confers adverse prognosis in early colorectal cancer

Colorectal cancer (CRC) is a biologically and clinically heterogeneous disease. Even though many recurrent genomic alterations have been identified that may characterize distinct subgroups, their biological impact and clinical significance as prognostic indicators remain to be defined. The tumor suppressor candidate-3 (TUSC3/N33) locates to a genomic region frequently deleted or silenced in cancers. TUSC3 is a subunit of the oligosaccharyltransferase (OST) complex at the endoplasmic reticulum (ER) which catalyzes bulk N-glycosylation of membrane and secretory proteins. However, the consequences of TUSC3 loss are largely unknown. Thus, the aim of the study was to characterize the functional and clinical relevance of TUSC3 expression in CRC patients’ tissues (n=306 cases) and cell lines. TUSC3 mRNA expression was silenced by promoter methylation in 85 % of benign adenomas (n=46 cases) and 35 % of CRCs (n =74 cases). Epidermal growth factor receptor (EGFR) was selected as one exemplary ER-derived target protein of TUSC3-mediated posttranslational modification. We found that TUSC3 inhibited EGFR-signaling and promoted apoptosis in human CRC cells, whereas TUSC3 siRNA knock-down increased EGFR-signaling. Accordingly, in stage I/II node negative CRC patients (n=156 cases) loss of TUSC3 protein expression was associated with poor overall survival. In sum, our data suggested that epigenetic silencing of TUSC3 may be useful as a molecular marker for progression of early CRC.