This project investigates how TRPC5 channels located in extracellular vesicles, contributes to cancer progression and chemoresistance. We will investigate calcium signaling in breast cancer using a vascularized chicken embryo (CAM) model, combining high-resolution fluorescence and Ca²⁺ imaging. Using photo-pharmacological tools to manipulate TRPC5, this study will assess how calcium-dependent extracellular vesicle transfer influences gene regulation, tumor remodeling, and chemoresistance development.
Project Details
Background:
Dysregulation of calcium signaling has been increasingly recognized as characteristic of different cancer cell types, contributing to survival and the resistance of the tumors to conventional therapies. For example, coordinated Ca2+ oscillations resulted in rapid glioblastoma growth that make this tumor resistant to chemotherapy1. In addition, chemoresistance of breast cancers has correlated with higher TRPC5 expression in these tumor cells2. Interestingly, extracellular vesicles (EVs), which contain functional TRPC5 channels have been suggested as a basis for spreading of chemoresistance within a tumor entity and thereby contribute to disease progression.2
Hypothesis and Objectives:
We will investigate the release of TRPC5 EVs from breast cancer tumor cells for the progression of the tumor using a vascularized in-vivo embryonic chicken tumor model, known as CAM assay3. Ex-ovo breast cancer tumor progression will be investigated for one week, and at the same time we will monitor Ca2+ and fluorescence imaging of the progressing tumor to determine the role of TRPC5 in chemoresistance development. Our objective is to monitor the formation and transfer of fluorescent labeled TRPC5 EVs and the Ca2+ signals associated with this process in the involved tumor cells with high spatiotemporal resolution. In addition, we will investigate Ca2+-dependent gene regulation programs, e.g. of NFAT in single tumor cells and on CAM tumors to determine tumor remodeling over days. We hypothesize that high-precision modulation of Ca2+ signaling by photo-pharmacological modulation of TRPC5 will manipulate EV transfer, progression of chemoresistance and tumor remodeling.
Methodology:
The PhD student will be trained in long-term in vivo tumor fluorescence microscopy using the embryonic chicken tumor assay (CAM assay) to monitor TRPC5 expressing EV transfer throughout the tumor. Breast cancer cells will be genetically engineered to express fluorescently labeled TRPC5, highly sensitive Ca2+ sensors, and a reporter vector to track NFAT-dependent transcription and then onplanted on CAM assay. Optical imaging will assess tumor proliferation, invasion, and vascularization. High-resolution imaging will capture TRPC5 EV release in single breast cancer cells and their transfer between tumor cells. Photo-pharmacological manipulation of TRPC5 will reveal its role in EV formation, the contribution of Ca2+ signaling, and how the associated Ca2+ signals drive gene regulation and chemoresistance.
References
1. Hausmann et al. (2022) Autonomous rhythmic activity in glioma networks drives brain tumour growth Nature 613(7942):179-186
2. Wang et al. (2016) Increasing circulating exosomes-carrying TRPC5 predicts chemoresistance in metastatic breast cancer patients Cancer Science 108 (2017) 448–454
3. Handl et al. (2024) Continuous iontronic chemotherapy reduces brain tumor growth in embryonic avian in vivo models J Control Release :369:668-683
People Involved
Primary supervisor: Rainer Schindl
Collaborators: