Abstract 4219: Establishing CAF-like and TAM-like transformation induced by TNBC culture supernatant in 3D in-vitro culture as a model for targeted drug testing

Abstract Several previous studies have highlighted the significance of cell-to-cell communication, or crosstalk, between tumor cells and non-tumorigenic cells in the context of cancer progression and metastasis. Within the tumor microenvironment (TME), these interactions have the potential to alter the phenotypes and behaviors of normal cells. The use of 2D in-vitro cultures has been limited due to their inability to accurately replicate the intricate in-vivo TME. Conditioned medium (CM) derived from cultured cancer cells contains secreted factors that may influence the phenotype and functionality of normal cells. In our investigation, the exposure of normal murine fibroblast NIH3T3 and macrophage RAW 264.7 cells to conditioned medium (CM) obtained from malignant mammary epithelial 4T1 cells (4T1CM) resulted in a modified phenotype with enhanced cell viability. Treatment with 4T1CM led to the upregulation of genes, including α-smooth muscle actin (αSMA), IL-10, CD206, and vascular endothelial growth factor (VEGF), in NIH3T3 and RAW 264.7 cells compared to their respective control cells. Additionally, NIH3T3 cells treated with 4T1CM exhibited an epithelial-mesenchymal transition (EMT) phenotype, as indicated by the regulation of EMT markers such as E-cadherin, β-catenin, N-cadherin, and Vimentin. Notably, RAW 264.7 cells treated with 4T1CM showed an upregulation of cyclooxygenase-2 (COX-2) and programmed death-ligand 1 (PDL-1), suggesting a propensity for an inhibitory immune response. Moreover, NIH3T3 cells conditioned with 4T1CM demonstrated an upregulation of stemness markers, including sex determining region Y-box 2 and Aldehyde dehydrogenase. In summary, our study highlights the potential role of 4T1CM in transforming normal NIH3T3 and RAW 264.7 cells into cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs). Ongoing proteomics analysis aims to map differentially expressed proteins potentially regulating the 4T1CM-induced transformation. To further investigate, a series of experiments using mono- and co-cultures of these cells are underway, specifically targeting the transformed macrophages and fibroblasts with the aim of either re-educating or eliminating them. This treatment involves drug combinations that specifically target the identified signaling pathway intermediates, offering novel therapeutic intervention strategies. Citation Format: Biplov Sapkota, Naveen Chintalaramulu, Abhishek Pandit, Shilpa Thota, Rizwana Begum, Amirsalar Mansouri, Jiri Adamec, Joseph Francis. Establishing CAF-like and TAM-like transformation induced by TNBC culture supernatant in 3D in-vitro culture as a model for targeted drug testing [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4219.