Abstract C43: Role of microRNAs in determining the cancer associated fibroblast phenotype

Abstract

Listen

Translate article

Abstract Cancer-associated fibroblasts (CAF) are among the predominant cell types present within the tumour microenvironment. The presence of CAF expressing markers of myofibroblast transdifferentiation is associated with high-grade malignancies and poor prognoses in human diseases. The molecular mechanisms underlying myofibroblast transdifferentiation in CAF however, remain poorly understood. MicroRNAs regulate many biological processes, but their role in determining the fate of fibroblasts in the tumour microenvironment remains unclear. Objective: To elucidate the role of miRNA in the conversion of resident fibroblast to myofibroblastic CAF. Methods: Human primary oral fibroblasts were treated with different concentrations of TGF-β (0.05-5 ng/ml) for 24 and 48 hrs. Markers of CAF transdifferentiation such as alpha-smooth muscle actin (α-SMA) and fibronectin-EDA (FN-EDA) were analysed using qRT-PCR. Protein expression of α-SMA was analysed by western blot and formation of stress fiber was visualised using immunocytochemistry. Collagen gels were used to analyse fibroblast contractility and Taqman Low Density Array (TLDA) and qRT-PCR to determine miRNA expression profiles of experimentally-derived CAF. Results: qRT-PCR and western blotting demonstrated an increase in α-SMA expression in TGF-β-induced, experimentally-derived CAF. TGF-β induced stress fiber formation and enhanced contraction of fibroblasts. TGF-β induced differential expression of a number of miRNAs in experimentally-derived CAF, including; miR-424, miR-200c and miR-145. Conclusion: The role of miRNAs in the phenotypic changes observed in CAF has not been studied extensively. Here we show widespread alterations in miRNA expression profiles of experimentally-derived myofibroblastic CAF. Future studies will examine the role of these miRNA in reprogramming of normal fibroblasts to CAF-like phenotype and examine whether miRNA alterations contribute to the heterogeneity of the CAF phenotype observed in vivo. Citation Format: Siti Amalina Zainal Abidin, Stuart Hunt, Dan Lambert. Role of microRNAs in determining the cancer associated fibroblast phenotype. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr C43.