Characterization of tumor-derived mesenchymal stem cells potentially differentiating into cancer-associated fibroblasts in lung cancer.

PURPOSE: The goal of this study was to understand if mesenchymal stem cells isolated from lung tumor tissue (T-MSCs) may differentiate into cancer associated fibroblasts (CAFs), that promote neoplastic progression, angiogenesis and metastasis in the epithelial solid tumors, mimicking the tumor microenvironmental influence.

METHODS: MSCs were been obtained from healthy (Control, C-MSCs) and tumor (T-MSCs) tissue of one patient who underwent a lobectomy for a lung adenocarcinoma pT1bN0. Isolated cells were characterized for the presence of molecular markers (identified by routine diagnostic characterization in differentiated tumoral cells), stemness properties, and CAF-related markers expression. Subsequently, cells were co-cultured with a lung adenocarcinoma cell line (A549 cells) to evaluate the effects on proliferation, oncogene expression and IL6 secretion.

RESULTS: C- and T-MSCs did not present EGFR mutations unlike tumor tissue and showed a stem-like immunophenotype, characterized by the ability to differentiate towards osteo-, chondro- and adipogenic lineages. The expression of markers referred to CAFs (α-SMA, HI-1α, MMP11, VEGF, CXCL12, TGF-β1, TGF-βRII, IL6, TNFα) was significantly higher in T-MSCs than in C-MSCs. The co-cultures with A549 cells led to the over-expression of selected oncogenes and to the increase of IL6 secretion in T-MSCs but not in C-MSCs.

CONCLUSIONS: MSCs isolated from tumor tissue displayed distinct properties compared to MSCs isolated from healthy tissue, suggesting T-MSCs differentiation towards a CAF-related phenotype under the influence of the tumoral microenvironment.