CPAM type 2‐derived mesenchymal stem cells: Malignancy risk study in a 14‐month‐old boy

Gloria Pelizzo, Maria A. Avanzini, Marco Folini, Rossana Bussani, Melissa Mantelli, Stefania Croce, Gloria Acquafredda, Paola Travaglino, Graziella Cimino‐Reale, Marina Boni, Irene Dambruoso, Valeria Calcaterra

The association between congenital pulmonary airway malformations (CPAM) and malignancy is reported in the literature. Interactions between the tumor, immune, and mesenchymal stromal/stem cells (MSCs) have been recognized as crucial for understanding tumorigenesis. We characterized MSCs isolated from CPAM lesions in order to define potential malignancy risks. CPAM II pulmonary tissue was used for MSC expansion; a "healthy" lung section from the same child was used as a comparator. Morphology, immunophenotype, differentiation and immunological capacity, proliferative growth, gene signature telomerase activity, and in vivo tumorigenicity in nude mice were evaluated. MSCs were successfully isolated and propagated from CPAM tissue. CPAM-MSCs presented the typical MSC morphology and phenotype, while exhibiting high proliferative capacity, reaching confluence at a median time of 5 days as well as differentiation capabilities. CPAM-MSCs at early passages were not neoplastic and chromosomally normal, even though unbalanced chromosomal rearrangements were noted by molecular karyotype. CPAM-MSCs exhibited specific features similar to tumor derived MSCs. Whilst there was no evidence of malignant transformation in the cystic tissue, our results provide evidence that this abnormal tissue has malignant potential. MSCs are considered important players in the tumor microenvironment and they have been closely linked to regulation of tumor survival, growth, and progression. Thus, early lesion resection also in asymptomatic patients might be indicated to exclude that the microenvironment may be potentially permissive to cancer development.