Deepening a Simple Question: Can MSCs Be Used to Treat Cancer?

In cancer, mesenchymal stem/stromal cells (MSCs) have been considered as vehicles for targeted delivery of drugs due to their inherent tropism toward primary and metastatic tumors. However, it is still unclear whether MSCs could be therapeutically explored without significant harm, since a great amound of evidence indicates that MSCs are able to exert both tumor-suppressive and pro-oncogenic effects. Here, we discuss how MSCs might adopt a pro- or anti-inflammatory profile in response to changes within the tumor microenvironment and how these features may lead to opposite outcomes in tumor development. Additionally, we address how differences in experimental design might impact interpretation and consistency of the current literature in this specific field. Finally, we point-out critical issues to be addressed at a pre-clinical stage, regarding safety and therapeutic effectiveness of MSCs application in cancer treatment.

A new mouse model for marfan syndrome presents phenotypic variability associated with the genetic background and overall levels of Fbn1 expression.

Marfan syndrome is an autosomal dominant disease of connective tissue caused by mutations in the fibrillin-1 encoding gene FBN1. Patients present cardiovascular, ocular and skeletal manifestations, and although being fully penetrant, MFS is characterized by a wide clinical variability both within and between families. Here we describe a new mouse model of MFS that recapitulates the clinical heterogeneity of the syndrome in humans. Heterozygotes for the mutant Fbn1 allele mgΔloxPneo, carrying the same internal deletion of exons 19-24 as the mgΔ mouse model, present defective microfibrillar deposition, emphysema, deterioration of aortic wall and kyphosis. However, the onset of a clinical phenotypes is earlier in the 129/Sv than in C57BL/6 background, indicating the existence of genetic modifiers of MFS between these two mouse strains. In addition, we characterized a wide clinical variability within the 129/Sv congenic heterozygotes, suggesting involvement of epigenetic factors in disease severity. Finally, we show a strong negative correlation between overall levels of Fbn1 expression and the severity of the phenotypes, corroborating the suggested protective role of normal fibrillin-1 in MFS pathogenesis, and supporting the development of therapies based on increasing Fbn1 expression.