P1: Heterogeneity of cGMP signaling in the tumor microenvironment

Aims

This project builds on the results obtained by our doctoral researchers during the first funding period of the RTG. They discovered an important role of cGMP signaling in the tumor microenvironment. In the second funding period, we will define the biochemical and cellular mechanisms and therapeutic potential of cGMP signaling in melanoma and breast cancer, with a focus on cGMP’s effects on tumor vessels and blood flow.

Questions and Methods

cGMP and the tumor microenvironment

We will use our established mouse models for melanoma and breast cancer known to express cGMP signaling components in the tumor microenvironment.
A special focus will be on how cGMP in smooth muscle cells (SMCs) and pericytes of tumor vessels influences tumor growth and malignancy. We will study how pharmacological or genetic manipulation of cGMP signaling affects vascular remodeling and blood flow in the tumor.
Is tumor growth/metastasis altered by cGMP-elevating drugs, in particular NO-GC stimulators (riociguat, vericiguat)?
In vivo experiments will be performed in mice with tumors under control conditions and after administration of NO-GC stimulators, and in cell type-specific mouse mutants lacking NO-GC or cGKI in SMCs/pericytes. All required mouse lines are available in the lab.
To obtain mechanistic insights, in vivo studies will be complemented by in vitro experiments with cultured cells (mouse and human cell lines and primary cells).
We will use our "cGMP sensor mice" for FRET imaging of cGMP signals in live cells in the culture dish as well as in tissue sections of dissected tumors. We will also establish “in situ” cGMP imaging and blood flow measurements in tumor vessels by intravital multiphoton microscopy. Moreover, tumor vascularization will be studied in 3D by light-sheet microscopy (collaboration with Prof. B. Weigelin, Preclinical Imaging Center, Tübingen).
A pericyte tracking system based on our “TK PET reporter mouse” will be used for noninvasive longitudinal monitoring of tumor vascularization in the absence and presence of NO-GC stimulators.
We will also address the question of whether co-treatment with NO-GC stimulators enhances anti-tumor effects of chemotherapy or immunotherapy (collaboration with P10)?

Boston Internship

Fukumura Lab

In the Fukumura lab in Boston, the doctoral researchers will be trained in cancer biology and state-of-the-art methods including multiphoton intravital microscopy of tumors in mice. They will also learn how to analyze the tumor stroma by immunofluorescence staining.

Boston Co-mentor

Assoc. Prof. Dai Fukumura MD, PhD

link to Boston researcher lab

Doctoral Students

Julia Hoffmeister

Julia Hoffmeister obtained her bachelor’s degree in biology at the University of Hamburg, where she developed an interest in microbiology and metagenomics. In her bachelor thesis Julia performed functional screenings of gene libraries in the search of novel glycosyltransferases. Julia continued her studies with a consecutive master’s program and completed her master thesis at the Leibniz Institute of Virology. Here, she researched the impact of H3N2 influenza A viruses on the expression of aromatase, which is the enzyme that metabolizes testosterone to estradiol.

After obtaining her M. Sc. degree Julia decided to expand her knowledge on biomedicine by switching to a different field, which is how she came to pursue a PhD at the group of Prof. Dr. Robert Feil.
Today, she is a member of Project 1 of the GRK 2381 “cGMP: From Bedside to Bench” and her research focuses on the role of cGMP signalling pathways in cancer.

Mariagiovanna Barresi (graduated in November 2023)

Mariagiovanna obtained her B.Sc. in Biotechnology at the University of Padua, Italy, where she developed a strong interest in cancer research. Her Bachelor’s thesis focused on the validation of a new zebrafish reporter line for STAT3, protein which is involved in uncontrolled tumor proliferation. Then, she continued her studies earned her Master’s degree in Industrial Biotechnology in Padua. She did her Master’s thesis in the Functional Genomics Lab of G. Lanfranchi in the Department of Biology and CRIBI Biotechnology Centre, moving her interest on the study of non-coding RNAs, such as miRNAs, to analyse how their expression, if altered, can determine or influence invasiveness and therefore progression in malignant melanoma. After her M.Sc., Mariagiovanna joined in the laboratory of Robert Feil to do her PhD. Here, her research focusses on the role of cGMP signalling in cancer.

Jennifer Schulz (until February 2023)

Jennifer Schulz obtained her B.Sc. in biology at the Justus-Liebig-University of Gießen with an emphasis in immunology, micro- and molecular biology. In her master´s studies at the Justus-Liebig-University in Gießen, she focused on biomedicine. Due to her strong interest in pharmacology and signaling pathways, she completed her master´s thesis at the Rudolf-Buchheim-Institute of pharmacology in Gießen. Her thesis was about the function of the nuclear cap-binding complex in epithelial cells and its association to the IL-1 signaling pathway as well as diseases. An internship at the ICM at the Uppsala University encouraged her to strive towards a scientific career. After completing her M.Sc., Jennifer took the opportunity as a doctoral student of the GRK2381 “cGMP: From Bedside to Bench” in the group of Robert Feil to follow her keen interest in the investigation of molecular mechanisms and their association to diseases. Her project focuses on the visualization and investigation of the role of cGMP in cancer.

Krithika Rajeeth (graduated in March 2024)

Krithika obtained her B.Sc. in biotechnology from SRM University, India, with a focus on molecular biology. After completing her bachelor’s, she earned a master's degree in Biochemistry from Ruhr Universität Bochum. She did her master thesis at the Institute of Molecular Oncology and Experimental Therapeutics at Marien Hospital Herne. Her master thesis focused on investigating the mechanism of epithelial mesenchymal transition in ovarian cancer. After M.Sc., Krithika joined the group of Prof. Robert Feil. Here, her PhD thesis focuses on investigating the role of cGMP signalling in non-alcoholic steatohepatitis (NASH) and liver fibrosis.

Daniel Stehle (associated PhD student, graduated in summer 2022)

Daniel studied Biochemistry in Tübingen. His interests guided him towards the fields of oncology and immune response. Consequently, he finished his Bachelor in the department of immunology. In his Master studies, Daniel deepened his experience in cell biology. This is also reflected in the topic of his Master’s thesis, where he analyzed functional aspects of apoptosis induction. After earning his M.Sc., Daniel did his PhD in the Feil laboratory. His research focusses on the role of cGMP in melanoma, with a focus on the tumor microenvironment. Daniel graduated in summer 2022 with "summa cum laude" and subsequently received start-up funding to support his further career as a potdoc at the IFIB (see also here).

Key Publications

Feil S, Stowbur D, Schorg BF, Ehrlichmann W, Reischl G, Kneilling M, Pichler BJ, Feil R. 2023. Noninvasive detection of smooth muscle cell-derived hot spots to study atherosclerosis by PET/MRI in mice. Circ Res 2023, 132:747-50. doi:10.1161/CIRCRESAHA.122.322296 [Press Release]

Stehle D, Barresi M, Schulz J, Feil R. Heterogeneity of cGMP signalling in tumour cells and the tumour microenvironment: Challenges and chances for cancer pharmacology and therapeutics. Pharmacol Ther 2023, 242:108337.

Tikoo S, Jain R, Tomasetig F, On K, Martinez B, Heu C, Stehle D, Obeidy P, Guo D, Vincent JN, Cook AJL, Roediger B, Feil R, Whan RM, Weninger W. Amelanotic B16-F10 melanoma compatible with advanced three-dimensional imaging modalities. J Invest Dermatol 2021, 141:2090-4 e6.

Dhayade S, Kaesler S, Sinnberg T, Dobrowinski H, Peters S, Naumann U, Liu H, Hunger RE, Thunemann M, Biedermann T, Schittek B, Simon HU, Feil S, Feil R. Sildenafil potentiates a cGMP-dependent pathway to promote melanoma growth. Cell Rep 2016, 14:2599-610.

Thunemann M, Wen L, Hillenbrand M, Vachaviolos A, Feil S, Ott T, Han X, Fukumura D, Jain RK, Russwurm M, de Wit C, Feil R. Transgenic mice for cGMP imaging. Circ Res 2013, 113:365-71.