Abstract
BackgroundAdipose-tissue stem cells (ASCs) are subject of intensive research since their successful use in regenerative therapy. The drawback of ASCs is that they may serve as stroma for cancer cells and assist tumor progression. It is disquieting that ASCs frequently undergo genetic and epigenetic changes during their in vitro propagation. In this study, we describe the polyploidization of murine ASCs and the accompanying phenotypical, gene expressional and functional changes under long term culturing.MethodsASCs were isolated from visceral fat of C57BL/6 J mice, and cultured in vitro for prolonged time. The phenotypical changes were followed by microscopy and flow cytometry. Gene expressional changes were determined by differential transcriptome analysis and changes in protein expression were shown by Western blotting. The tumor growth promoting effect of ASCs was examined by co-culturing them with 4 T1 murine breast cancer cells.ResultsAfter five passages, the proliferation of ASCs decreases and cells enter a senescence-like state, from which a proportion of cells escape by polyploidization. The resulting ASC line is susceptible to adipogenic, osteogenic and chondrogenic differentiation, and expresses the stem cell markers CD29 and Sca-1 on an upregulated level. Differential transcriptome analysis of ASCs with normal and polyploid karyotype shows altered expression of genes that are involved in regulation of cancer, cellular growth and proliferation. We verified the increased expression of Klf4 and loss of Nestin on protein level. We found that elevated production of insulin-like growth factor 1 by polyploid ASCs rendered them more potent in tumor growth promotion in vitro.ConclusionsOur model indicates how ASCs with altered genetic background may support tumor progression.
Highlights
Adipose-tissue stem cells (ASCs) are subject of intensive research since their successful use in regenerative therapy
We demonstrate that ASCs with abnormal chromosomal number enhance the proliferation of breast cancer cells via insulin-like growth factor 1 (IGF1) production
We noticed that the proliferation of visceral ASC (vASC) slowed down and the cell number decreased after 5–6 passages, which meant approximately 3 weeks (18–22 days) in vitro culturing (Fig. 1a)
Summary
Adipose-tissue stem cells (ASCs) are subject of intensive research since their successful use in regenerative therapy. Stem cell-based therapies for treatment of a wide range of diseases are becoming increasingly important. Adult stem cells appear to be the safest and most reliable source of stem and progenitor cells for tissue engineering and repair. The most widely used cell types for stem cell-based therapies are the mesenchymal stem cells (MSCs). MSCs are multipotent progenitors; they have the ability to differentiate into cartilage, bone, connective, muscle, and adipose tissue [1]. Adipose tissue contains a biologically and clinically intriguing heterogeneous cell population called stromal vascular fraction (SVF) from which the adipose stem cells (ASCs) can be extracted in large quantities and can be cultured and expanded.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
