Diversity of primary Breast cancer-associated fibroblasts (BCAFs) assessed through intracellular signalling pathway dynamics

Cancer is a highly heterogeneous disease characterised by complex interactions between tumour cells and its microenvironment, as well as substantial variability between patients. Breast cancer shows one of the most prevalent in female and remains life-threatening malignancies worldwide. Among the microenvironmental components, cancer-associated fibroblasts (CAFs) play critical roles in tumour progression and therapeutic resistance. Although gene expression profiling and proteomics have advanced the characterisation of tumour heterogeneity, these approaches do not completely describe the diversity on a functional level, particularly within diverse CAF populations.
This thesis investigates the functional diversity between different breast cancer-associated fibroblast cell lines by using calcium signalling dynamics as readout of growth factor responsiveness. Patient- derived primary CAFs and normal fibroblasts (NFs) were systematically analysed using an automated high-throughput platform that enables detailed calcium response profiling. Distinct response patterns were identified among CAF populations, revealing substantial inter-patient variability and functional subtypes that were not apparent from conventional molecular profiling approaches. Compared with normal fibroblasts, CAFs exhibited altered sensitivity and signalling dynamics in response to growth factor stimulation, indicating the tumour-associated functional reprogramming.
To assess the broader applicability of this functional profiling approach, the methodology was extended to primary glioblastoma cell lines, enabling cross-tumour comparisons and demonstrating tumour specific response profiles.
Together, these findings demonstrate that calcium response profiling provides a powerful functional framework for characterising tumour cell heterogeneity. This approach offers insights into tumour microenvironment biology and provides a possibility to support the development of more precise therapeutic strategies targeting breast cancer.