Activated fibroblasts, aka Cancer-Associated Fibroblasts (CAFs), comprise a population of stromal cells within the heterogenous tumor microenvironment that promote cancer growth by inducing extracellular matrix remodeling, angiogenesis, recruitment of immune cells, and migration of tumor cells. Transformation of local or recruited naïve fibroblasts (NFs) into CAFs has been documented in solid tumors derived from cancer patients. This step is triggered by the crosstalk between the fibroblasts and the tumor cells, resulting in the upregulation of specific markers, including a-SMA, FAP, vimentin, and PDGFRα, which have been used to identify and study the various CAF populations. However, marker variation within CAF populations is extensive due to their extremely heterogeneous nature and high plasticity making marker-based identification of CAF unreliable and contradicting between subpopulations at times. Furthermore, although reprogramming of fibroblasts to CAFs via interactions with the tumor cells has been recapitulated in vitro using regular 2D cultures, it has yet to be evaluated in 3D cultures that mimic in vivo solid tumors to find out possible contextual differences.
The current research aims to study the effect of the human breast cancer cell line (T47D cells) on reprogramming of NFs into CAFs using Human Forehead Fibroblasts (HFF cells) by comparing expression of various CAF markers using 2D and 3D cultures. Tumor-induced education of CAFs will be evaluated using 2 different approaches: a- Indirect approach where NFs are cultured in the presence of tumor cell-derived factors present in collected conditioned medium. b- Direct approach where NFs are co-cultured along with tumor cells. Results from the current studies will add more clarity to the growing field of CAFs and provide a model system to further assess the different functions of CAFs. Ultimately, our developed 3D studies aim to target CAF populations using novel and specific approaches.
