scholarly journals Irradiation strongly reduces tumorigenesis of human induced pluripotent stem cells

2017 ◽  
Vol 58 (4) ◽  
pp. 430-438 ◽  
Author(s):  
Shoki Inui ◽  
Kazumasa Minami ◽  
Emiko Ito ◽  
Hiromasa Imaizumi ◽  
Seiji Mori ◽  
...  

Abstract Induced pluripotent stem (iPS) cells have demonstrated they can undergo self-renewal, attain pluripotency, and differentiate into various types of functional cells. In clinical transplantation of iPS cells, however, a major problem is the prevention of tumorigenesis. We speculated that tumor formation could be inhibited by means of irradiation. Since the main purpose of this study was to explore the prevention of tumor formation in human iPS (hiPS) cells, we tested the effects of irradiation on tumor-associated factors such as radiosensitivity, pluripotency and cell death in hiPS cells. The irradiated hiPS cells showed much higher radiosensitivity, because the survival fraction of hiPS cells irradiated with 2 Gy was < 10%, and there was no change of pluripotency. Irradiation with 2 and 4 Gy caused substantial cell death, which was mostly the result of apoptosis. Irradiation with 2 Gy was detrimental enough to cause loss of proliferation capability and trigger substantial cell death in vitro. The hiPS cells irradiated with 2 Gy were injected into NOG mice (NOD/Shi-scid, IL-2 Rγnull) for the analysis of tumor formation. The group of mice into which hiPS cells irradiated with 2 Gy was transplanted showed significant suppression of tumor formation in comparison with that of the group into which non-irradiated hiPS cells were transplanted. It can be presumed that this diminished rate of tumor formation was due to loss of proliferation and cell death caused by irradiation. Our findings suggest that tumor formation following cell therapy or organ transplantation induced by hiPS cells may be prevented by irradiation.

2012 ◽  
Vol 14 (4) ◽  
pp. 574-579 ◽  
Author(s):  
Yong Zhu ◽  
Hong-Liang Hu ◽  
Peng Li ◽  
Shi Yang ◽  
Wei Zhang ◽  
...  

Author(s):  
Warunya Chakritbudsabong ◽  
Somjit Chaiwattanarungruengpaisan ◽  
Ladawan Sariya ◽  
Sirikron Pamonsupornvichit ◽  
Joao N. Ferreira ◽  
...  

Porcine species have been used in preclinical transplantation models for assessing the efficiency and safety of transplants before their application in human trials. Porcine-induced pluripotent stem cells (piPSCs) are traditionally established using four transcription factors (4TF): OCT4, SOX2, KLF4, and C-MYC. However, the inefficiencies in the reprogramming of piPSCs and the maintenance of their self-renewal and pluripotency remain challenges to be resolved. LIN28 was demonstrated to play a vital role in the induction of pluripotency in humans. To investigate whether this factor is similarly required by piPSCs, the effects of adding LIN28 to the 4TF induction method (5F approach) on the efficiency of piPSC reprogramming and maintenance of self-renewal and pluripotency were examined. Using a retroviral vector, porcine fetal fibroblasts were transfected with human OCT4, SOX2, KLF4, and C-MYC with or without LIN28. The colony morphology and chromosomal stability of these piPSC lines were examined and their pluripotency properties were characterized by investigating both their expression of pluripotency-associated genes and proteins and in vitro and in vivo differentiation capabilities. Alkaline phosphatase assay revealed the reprogramming efficiencies to be 0.33 and 0.17% for the 4TF and 5TF approaches, respectively, but the maintenance of self-renewal and pluripotency until passage 40 was 6.67 and 100%, respectively. Most of the 4TF-piPSC colonies were flat in shape, showed weak positivity for alkaline phosphatase, and expressed a significantly high level of SSEA-4 protein, except for one cell line (VSMUi001-A) whose properties were similar to those of the 5TF-piPSCs; that is, tightly packed and dome-like in shape, markedly positive for alkaline phosphatase, and expressing endogenous pluripotency genes (pOCT4, pSOX2, pNANOG, and pLIN28), significantly high levels of pluripotent proteins (OCT4, SOX2, NANOG, LIN28, and SSEA-1), and a significantly low level of SSEA-4 protein. VSMUi001-A and all 5F-piPSC lines formed embryoid bodies, underwent spontaneous cardiogenic differentiation with cardiac beating, expressed cardiomyocyte markers, and developed teratomas. In conclusion, in addition to the 4TF, LIN28 is required for the effective induction of piPSCs and the maintenance of their long-term self-renewal and pluripotency toward the development of all germ layers. These piPSCs have the potential applicability for veterinary science.


2022 ◽  
Author(s):  
Tim Vervliet ◽  
Robin Duelen ◽  
lLewelyn H Roderick ◽  
Maurilio Sampaolesi

Anti-apoptotic B-cell lymphoma 2 (Bcl-2) regulates a wide array of cellular functions involved in cell death, cell survival decisions and autophagy. Bcl-2 acts by both direct interaction with different components of the pathways involved and by intervening in intracellular Ca2+ signalling. The function of Bcl-2 is in turn regulated by post-translational modifications including phosphorylation at different sites by various kinases. Besides functions in cell death and apoptosis, Bcl-2 regulates cell differentiation processes, including of cardiomyocytes, although the signalling pathways involved are not fully elucidated. To further address the role of Bcl-2 during cardiomyocyte differentiation, we investigated the effect of its genetic knockout by CRISPR/Cas9 on the differentiation and functioning of human induced pluripotent stem cells to cardiomyocytes. Our results indicate that differentiation of iPS cells to cardiomyocytes is delayed by Bcl-2 KO, resulting in reduced size of spontaneously beating cells and reduced expression of cardiomyocyte Ca2+ toolkit and functionality. These data thus indicate that Bcl-2 an essential protein for cardiomyocyte generation.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 497-497
Author(s):  
Suneet Agarwal ◽  
Yuin-Han Loh ◽  
Erin M McLoughlin ◽  
Junjiu Huang ◽  
In-Hyun Park ◽  
...  

Abstract Abstract 497 Patients with dyskeratosis congenita (DC), a disorder of telomere maintenance, suffer premature degeneration of multiple tissues. Bone marrow failure is the principal cause of mortality, and allogeneic stem cell transplantation is limited by increased treatment-related mortality. Somatic cells can be reprogrammed using defined genetic and chemical factors, yielding “induced pluripotent stem” (iPS) cell lines which have the capacity to differentiate into any tissue. Patient-specific iPS cells therefore hold promise as therapeutic agents and disease models for human degenerative disorders like DC. A cardinal feature of iPS cells is acquisition of indefinite self-renewal capacity, and we have found that telomere length is increased in human iPS cells relative to the normal primary somatic cells from which they are derived. Here we investigated whether defects in telomerase function would limit derivation or self-renewal of iPS cells from patients with DC. We reprogrammed primary fibroblasts from patients with X-linked and autosomal dominant DC, caused by mutations in the genes encoding dyskerin and telomerase RNA component (TERC), respectively. We were able to establish multiple DC-specific iPS lines showing all hallmarks of pluripotency, including the formation of hematopoietic progenitors in vitro. Unexpectedly, DC-specific iPS cells were able to sustain continual proliferation in vitro, in contrast to the premature senescence displayed by the DC fibroblasts. Although early passage DC iPS cells had shorter telomeres than donor fibroblasts, we found that telomere length in DC iPS cells increased with continued passage in culture. To explain this finding, we discovered that steady state levels of TERC, which are critically limiting in several forms of DC, are upregulated in normal and DC iPS cells. We found that TERC upregulation is a feature of the pluripotent state, that the TERC locus is a target of pluripotency-associated transcription factors, and that transcriptional silencing accompanies a 3' deletion at the TERC locus in autosomal dominant DC. Our results demonstrate that reprogramming restores self-renewal capacity in DC cells despite genetic lesions affecting telomerase, and suggest that strategies to enhance endogenous TERC expression may be feasible and therapeutically beneficial in DC patients. The studies demonstrate the value of patient-specific iPS cells for basic and translational discovery, and further the rationale for autologous iPS based cellular therapy of genetic hematologic disorders. Disclosures: Daley: MPM Capital: Consultancy; Solasia: Consultancy; Epizyme: Consultancy; iPierian: Consultancy, Equity Ownership.


2009 ◽  
Vol 390 (9) ◽  
Author(s):  
Alexandra Rolletschek ◽  
Anna M. Wobus

Abstract Adult cells have been reprogrammed into induced pluripotent stem (iPS) cells by introducing pluripotency-associated transcription factors. Here, we discuss recent advances and challenges of in vitro reprogramming and future prospects of iPS cells for their use in diagnosis and cell therapy. The generation of patient-specific iPS cells for clinical application requires alternative strategies, because genome-integrating viral vectors may cause insertional mutagenesis. Moreover, when suitable iPS cell lines will be available, efficient and selective differentiation protocols are needed to generate transplantable grafts. Finally, we point to the requirement of a regulatory framework necessary for the commercial use of iPS cells.


2016 ◽  
Vol 113 (7) ◽  
pp. 1889-1894 ◽  
Author(s):  
Salvatore Iovino ◽  
Alison M. Burkart ◽  
Laura Warren ◽  
Mary Elizabeth Patti ◽  
C. Ronald Kahn

Induced pluripotent stem cells (iPS cells) represent a unique tool for the study of the pathophysiology of human disease, because these cells can be differentiated into multiple cell types in vitro and used to generate patient- and tissue-specific disease models. Given the critical role for skeletal muscle insulin resistance in whole-body glucose metabolism and type 2 diabetes, we have created a novel cellular model of human muscle insulin resistance by differentiating iPS cells from individuals with mutations in the insulin receptor (IR-Mut) into functional myotubes and characterizing their response to insulin in comparison with controls. Morphologically, IR-Mut cells differentiated normally, but had delayed expression of some muscle differentiation-related genes. Most importantly, whereas control iPS-derived myotubes exhibited in vitro responses similar to primary differentiated human myoblasts, IR-Mut myotubes demonstrated severe impairment in insulin signaling and insulin-stimulated 2-deoxyglucose uptake and glycogen synthesis. Transcriptional regulation was also perturbed in IR-Mut myotubes with reduced insulin-stimulated expression of metabolic and early growth response genes. Thus, iPS-derived myotubes from individuals with genetically determined insulin resistance demonstrate many of the defects observed in vivo in insulin-resistant skeletal muscle and provide a new model to analyze the molecular impact of muscle insulin resistance.


2015 ◽  
Vol 27 (1) ◽  
pp. 252
Author(s):  
J. Secher ◽  
K. Freude ◽  
S. Petkov ◽  
A. Ceylan ◽  
M. Schmidt ◽  
...  

Porcine-induced pluripotent stem cells (piPSC) have been established since 2009, but only 1 report demonstrated contribution to germline chimeras. One well-established in vivo pluripotency assay is the teratoma assay, which has recently been questioned due to the lack of standardized guidelines. In the present study we have characterised GFP-tagged in vitro and in vivo tetracycline-inducible piPSC [porcine MYC, SOX2, KLF4 (pOMSK)] and their capacity to form teratomas. We injected 1.5 million cells in 250 µL of PBS subcutaneous into NOD/SCID mice and followed them up to 6 weeks. The teratomas were analysed by immunohistochemistry for the 3 germlayer markers β3 tubulin, α fetoprotein, and smooth muscle actin. We not only found our teratomas positive for these markers, but also co-positive for GFP, clearly showing that the teratoma was made from porcine cells, which was not sufficiently proven in former studies. Our H&E staining revealed the following structures: cuboidal ephitelium, thyroid-like structure, renal corpuscle, and steroid producing cells. We continued to test the capacity of our venus iPS cells to contribute to in vitro chimeras. To achieve this we used a micromanipulator to inject 15 cells into Day 5 parthenotes, and subsequently cultured them in PZM3 with 10% FCS, cultured with or without doxycycline. These in vitro chimeras were followed until Day 7 in Nikons Biostation IM and used for differential staining. In all groups we saw good survival, hatching, and maintenance of GFP, indicating integration of these cells in our in vitro assay. We only found differences between survivals of the cell lines in the group cultured with doxycycline. Finally, in order to assess if the naïve type venus iPS cells could possibly be a truly naïve piPSC, we tested their capacity to form in vivo germline chimeras. This was tested by injecting 15 piPSC into Day 4 to 5 in vivo embryos. The injected embryos were transferred into 5 surrogate mothers, 3 of them were fed doxycycline before the transfer and 5 days after, and the last 2 recipient sows were not fed doxycycline. The pregnancies were terminated at Day 32 and the embryos were examined for fluorescence and the GFP transgene by PCR. In summary, it appears that both naïve type and primed type venus iPS cells are still strongly dependent on the pOMSK transgene expression, and the ultimate proof for pluripotency, the chimera production, seems to be not achievable under the condition we have chosen.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Leonhard Linta ◽  
Marianne Stockmann ◽  
Tobias M. Boeckers ◽  
Alexander Kleger ◽  
Stefan Liebau

α-synuclein is a protein involved in the pathogenesis of several so-called synucleinopathies including Parkinson's disease. A variety of models have been so far assessed. Human induced pluripotent stem cells provide a patient- and disease-specific model forin vitrostudies, pharmacotoxicological screens, and hope for future cell-based therapies. Initial experimental procedures include the harvest of patients’ material for the reprogramming process, the investigation of the patients genetic background in the cultured cells, and the evaluation of disease-relevant factors/proteins under various cell culture conditions.


2014 ◽  
Vol 23 (11) ◽  
pp. 1407-1423 ◽  
Author(s):  
Kyle D. Fink ◽  
Julien Rossignol ◽  
Ming Lu ◽  
Xavier Lévêque ◽  
Travis D. Hulse ◽  
...  

Induced pluripotent stem cells (iPSCs) offer certain advantages over embryonic stem cells in cell replacement therapy for a variety of neurological disorders. However, reliable procedures, whereby transplanted iPSCs can survive and differentiate into functional neurons, without forming tumors, have yet to be devised. Currently, retroviral or lentiviral reprogramming methods are often used to reprogram somatic cells. Although the use of these viruses has proven to be effective, formation of tumors often results following in vivo transplantation, possibly due to the integration of the reprogramming genes. The goal of the current study was to develop a new approach, using an adenovirus for reprogramming cells, characterize the iPSCs in vitro, and test their safety, survivability, and ability to differentiate into region-appropriate neurons following transplantation into the rat brain. To this end, iPSCs were derived from bone marrow-derived mesenchymal stem cells and tail-tip fibroblasts using a single cassette lentivirus or a combination of adenoviruses. The reprogramming efficiency and levels of pluripotency were compared using immunocytochemistry, flow cytometry, and real-time polymerase chain reaction. Our data indicate that adenovirus-generated iPSCs from tail-tip fibroblasts are as efficient as the method we used for lentiviral reprogramming. All generated iPSCs were also capable of differentiating into neuronal-like cells in vitro. To test the in vivo survivability and the ability to differentiate into region-specific neurons in the absence of tumor formation, 400,000 of the iPSCs derived from tail-tip fibroblasts that were transfected with the adenovirus pair were transplanted into the striatum of adult, immune-competent rats. We observed that these iPSCs produced region-specific neuronal phenotypes, in the absence of tumor formation, at 90 days posttransplantation. These results suggest that adenovirus-generated iPSCs may provide a safe and viable means for neuronal replacement therapies.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Zhanhui Ou ◽  
Min Luo ◽  
Xiaohua Niu ◽  
Yuchang Chen ◽  
Yingjun Xie ◽  
...  

Spinocerebellar ataxia-3 (SCA3) is the most common dominant inherited ataxia worldwide and is caused by an unstable CAG trinucleotide expansion mutation within the ATXN3 gene, resulting in an expanded polyglutamine tract within the ATXN3 protein. Many in vitro studies have examined the role of autophagy in neurodegenerative disorders, including SCA3, using transfection models with expression of pathogenic proteins in normal cells. In the current study, we aimed to develop an improved model for studying SCA3 in vitro using patient-derived cells. The patient-derived iPS cells presented a phenotype similar to that of human embryonic stem cells and could be differentiated into neurons. Additionally, these cells expressed abnormal ATXN3 protein without changes in the CAG repeat length during culture for at least 35 passages as iPS cells, up to 3 passages as neural stem cells, and after 4 weeks of neural differentiation. Furthermore, we demonstrated that neural differentiation in these iPS cells was accompanied by autophagy and that rapamycin promoted autophagy through degradation of mutant ATXN3 proteins in neurally differentiated spinocerebellar ataxia-3 human induced pluripotent stem cells (p<0.05). In conclusion, patient-derived iPS cells are a good model for studying the mechanisms of SCA3 and may provide a tool for drug discovery in vitro.


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