Martin Metzenmacher

Dr. Martin Metzenmacher


Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
4 February 2020 in Cancers
Verified
Journal Article
Open access
PDF file
MMMartin Metzenmacher
Martin Metzenmacher
RVRenata Varaljai
Renata Varaljai
BHBalazs Hegedus
Balazs Hegedus
ICIgor Cima
Igor Cima
JFJan Forster
Jan Forster
SLSmiths Lueong
Smiths Lueong
Early detection of cancer holds high promise for reducing cancer-related mortality. Detection of circulating tumor-specific nucleic acids holds promise, but sensitivity and specificity issues remain with current technology. We studied cell-free RNA (cfRNA) in patients with non-small cell lung cancer (NSCLC; n = 56 stage IV, n = 39 stages I-III), pancreatic cancer (PDAC, n = 20 stage III), malignant melanoma (MM, n = 12 stage III-IV), urothelial bladder cancer (UBC, n = 22 stage II and IV), and 65 healthy controls by means of next generation sequencing (NGS) and real-time droplet digital PCR (RT-ddPCR). We identified 192 overlapping upregulated transcripts in NSCLC and PDAC by NGS, more than 90% of which were noncoding. Previously reported transcripts (e.g., HOTAIRM1) were identified. Plasma cfRNA transcript levels of POU6F2-AS2 discriminated NSCLC from healthy donors (AUC = 0.82 and 0.76 for stages IV and I–III, respectively) and significantly associated (p = 0.017) with the established tumor marker Cyfra 21-1. cfRNA yield and POU6F2-AS transcript abundance discriminated PDAC patients from healthy donors (AUC = 1.0). POU6F2-AS2 transcript was significantly higher in MM (p = 0.044). In summary, our findings support further validation of cfRNA detection by RT-ddPCR as a biomarker for early detection of solid cancers.

17 November 2021 in Translational Oncology
Verified
Journal Article
Open access
MMMartin Metzenmacher
Martin Metzenmacher
BHBalazs Hegedus
Balazs Hegedus
JFJan Forster
Jan Forster
Alexander SchrammAlexander Schramm
Alexander Schramm
PHPeter Horn
Peter Horn
SLSmiths Lueong
Smiths Lueong
Radiology is the current standard for monitoring treatment responses in lung cancer. Limited sensitivity, exposure to ionizing radiations and related sequelae constitute some of its major limitation. Non-invasive and highly sensitive methods for early detection of treatment failures and resistance-associated disease progression would have additional clinical utility. We analyzed serially collected plasma and paired tumor samples from lung cancer patients (61 with stage IV, 48 with stages I-III disease) and 61 healthy samples by means of next-generation sequencing, radiological imaging and droplet digital polymerase chain reaction (ddPCR) mutation and methylation assays. A 62% variant concordance between tumor-reported and circulating-free DNA (cfDNA) sequencing was observed between baseline liquid and tissue biopsies in stage IV patients. Interestingly, ctDNA sequencing allowed for the identification of resistance-mediating p.T790M mutations in baseline plasma samples for which no such mutation was observed in the corresponding tissue. Serial circulating tumor DNA (ctDNA) mutation analysis by means of ddPCR revealed a general decrease in ctDNA loads between baseline and first reassessment. Additionally, serial ctDNA analyses only recapitulated computed tomography (CT) -monitored tumor dynamics of some, but not all lesions within the same patient. To complement ctDNA variant analysis we devised a ctDNA methylation assay (methcfDNA) based on methylation-sensitive restriction enzymes. cfDNA methylation showed and area under the curve (AUC) of > 0.90 in early and late stage cases. A decrease in methcfDNA between baseline and first reassessment was reflected by a decrease in CT-derive tumor surface area, irrespective of tumor mutational status. Taken together, our data support the use of cfDNA sequencing for unbiased characterization of the molecular tumor architecture, highlights the impact of tumor architectural heterogeneity on ctDNA-based tumor surveillance and the added value of complementary approaches such as cfDNA methylation for early detection and monitoring

16 June 2022 in Thoracic Cancer
Verified
Journal Article
Open access
MMMartin Metzenmacher
Martin Metzenmacher
BHBalazs Hegedus
Balazs Hegedus
JFJan Forster
Jan Forster
ASAlexander Schramm
Alexander Schramm
PHPeter A. Horn
Peter A. Horn
SLSmiths Lueong
Smiths Lueong
Background: CT scans are used in routine clinical practice for the diagnosis and treatment surveillance of non‐small cell lung cancer (NSCLC). However, more sensitive methods are desirable. Liquid biopsy analyses of RNA and DNA can offer more sensitive diagnostic approaches. Cell‐free RNA (cfRNA) has been described in several malignancies, but its clinical utility has not previously been explored.Methods: We evaluated the clinical utility of cfRNA for early detection and surveillance of tumor disease in a proof‐of‐concept study. Using real‐time‐droplet digital polymerase chain reaction we characterized a candidate transcript (MORF4L2) in plasma samples from 41 advanced stage, 38 early stage NSCLC and 39 healthy samples. We compared its diagnostic performance with tumor markers and evaluated its utility for disease monitoring.Results: MORF4L2 cfRNA was more abundant in patients than in healthy donors (p < 0.0001). Using the Youden index approach (cutoff value of 537 copies/ml was established) with a sensitivity of 0.73 (95% CI: 0.61–0.82) and a specificity of 0.87 (95% CI: 0.73–0.96). Positive and negative predictive values of 0.92 (95% CI: 0.83–0.95) and 0.59 (95% CI: 0.47–0.83) were achieved. Combination of cfRNA and Cyfra21‐1 improved its predictive value from 89.5% to 94.7%. Low baseline MORF4L2 levels were associated with better overall survival (HR:0.25, 95% CI: 0.09–0.7, p = 0.009) and progression‐free survival for patients treated with tyrosine kinase inhibitors (p = 0.011) and chemotherapy (p = 0.019). MORF4L2 profile between baseline and follow‐up mirrored radiological response and tumor dynamics better than tumor markers. cfRNA transcripts allowed monitoring tumor dynamics in patients without tumor‐reported genetic alterations.Conclusion: Our data support clinical utility of cfRNA for detection and surveillance of NSCLC. Further studies with larger cohorts are required.

24 May 2022 in Seminars in Nuclear Medicine
Verified
Journal Article
Closed access
PSPatrick Sandach
Patrick Sandach
RSRobert Seifert
Robert Seifert
WFWolfgang P. Fendler
Wolfgang P. Fendler
HHHubertus Hautzel
Hubertus Hautzel
KHKen Herrmann
Ken Herrmann
JFJustin Ferdinandus
Justin Ferdinandus

10 October 2012 in BMC Biotechnology
Verified
Journal Article
Open access
PDF file
GPGesine Pless-Petig
Gesine Pless-Petig
MMMartin Metzenmacher
Martin Metzenmacher
TTTobias R Türk
Tobias R Türk
URUrsula Rauen
Ursula Rauen
Background: In modern biotechnology, there is a need for pausing cell lines by cold storage to adapt large-scale cell cultures to the variable demand for their products. We compared various cell culture media/solutions for cold storage of Vero-B4 kidney cells, a cell line widely used in biotechnology.Results: Cold storage in RPMI 1640 medium, a recommended cell culture medium for Vero-B4 cells, surprisingly, strongly enhanced cold-induced cell injury in these cells in comparison to cold storage in Krebs-Henseleit buffer or other cell culture media (DMEM, L-15 and M199). Manufacturer, batch, medium supplements and the most likely components with concentrations outside the range of the other media/solutions (vitamin B12, inositol, biotin, p-aminobenzoic acid) did not cause this aggravation of cold-induced injury in RPMI 1640. However, a modified Krebs-Henseleit buffer with a low calcium concentration (0.42 mM), a high concentration of inorganic phosphate (5.6 mM), and glucose (11.1 mM; i.e. concentrations as in RPMI 1640) evoked a cell injury and loss of metabolic function corresponding to that observed in RPMI 1640. Deferoxamine improved cell survival and preserved metabolic function in modified Krebs-Henseleit buffer as well as in RPMI 1640. Similar Ca2+and phosphate concentrations did not increase cold-induced cell injury in the kidney cell line LLC-PK1, porcine aortic endothelial cells or rat hepatocytes. However, more extreme conditions (Ca2+was nominally absent and phosphate concentration raised to 25 mM as in the organ preservation solution University of Wisconsin solution) also increased cold-induced injury in rat hepatocytes and porcine aortic endothelial cells.Conclusion: These data suggest that the combination of low calcium and high phosphate concentrations in the presence of glucose enhances cold-induced, iron-dependent injury drastically in Vero-B4 cells, and that a tendency for this pathomechanism also exists in other cell types.

21 July 2021 in Future Oncology
Verified
Journal Article
Open access
MMMartin Metzenmacher
Martin Metzenmacher
FRFilippo Rizzo
Filippo Rizzo
KKKato Kambartel
Kato Kambartel
JPJens Panse
Jens Panse
DSDiana Schaufler
Diana Schaufler
DCDaniel C. Christoph
Daniel C. Christoph
Aim: This real-world analysis evaluated docetaxel plus nintedanib in patients with advanced pulmonary adenocarcinoma after chemotherapy and immune checkpoint inhibitor failure, for whom treatment o... Lay abstract The standard of care for patients with lung adenocarcinoma has advanced with the introduction of immunotherapy in the first-line setting. However, limited clinical data are available t...