Name: reprogramming pancreatic ductal adenocarcinoma to pluripotency
Uploaded: 2024-02-02T13:30:00.000+00:00
Duration: 7 min 8 s
Description: Watch this Scientific Journal Video about Reprogramming Pancreatic Ductal Adenocarcinoma to Pluripotency at JoVE.com

A.S and J.K would like to thank Cancer Research UK and OHSU for funding (CRUK-OHSU Project Award C65925/A26986). A.S is supported by an MRC career development award (MR/N024028/1). A.A is funded by a Ph.D. scholarship (Scholarship ref. 1078107040) from King Abdulaziz City for Science and Technology. J.K is funded by MRF New Investigator Grant (GCNCR1042A) and Knight CEDAR grant (68182-933-000, 68182-939-000). We thank Prof Keisuke Kaji for kindly providing the reprogramming vector pSIN4-EF1a-O2S and pSIN4-CMV-K2M. For the purpose of open access, the author has applied a Creative Commons Attribution (CC BY) licence to any Author Accepted Manuscript version arising from this submission.

All experimental protocols were approved by the OHSU Institutional Review Board. All methods were carried out in accordance with relevant guidelines and regulations. All animal works for PDX tumors were performed with the OHSU Institutional Animal Use and Care Committee (IACUC) approval. This protocol was tested in Primary PDAC cells from patient-derived xenograft (PDX), BxPc3 cell line exhibiting epithelial morphology that was isolated from the pancreas tissue of a 61-year-old female patient with adenocarcinoma, the H6C7 immortalized epithelial cell line derived from normal human pancreatic duct epithelial, and primary human fibroblasts derived from skin biopsy of healthy individuals. Human PDAC specimens were obtained under the Oregon Pancreas Tissue Registry study (IRB00003609). Informed consent was obtained from all subjects. Human primary fibroblasts were derived in RBiomedical, Edinburgh, UK, from skin samples from anonymous donors undergoing routine surgery at the Edinburgh Royal Infirmary, Little France, UK, under their consent and ethical approval (09/MRE00/91).All lentivirus work has been carried out under Class 2 research activity (GM207/16.6) and approved by the Health and Safety Department at the University of Edinburgh and notified to the HSE competent authority of the Scottish Government. All reprogramming experiments using human pancreatic cells were carried out under the ethical approval of the School of Biological Sciences ethics committee at the University of Edinburgh (reference # asoufi-0002).
1. Preparation of lentiviruses
<ol>
	<li>For lentivirus preparation, prepare high-quality packaging and expression plasmids (endotoxin-free) with concentrations between 1-2 &#181;g/&#181;L including psPAX2, pMDG34, and two RES-containing bicistronic vectors; the pSIN4-EF1a-O2S encoding for OCT4 and SOX2 expression driven by EF-1&#945; promoter, and pSIN4-CMV-K2M for KLF4 and c-MYC expression under the CMV enhancer/promoter35 (see Table of Materials). Also, prepare pWPT-GFP plasmid to be used as a transfection control.</li>
	<li>Thaw Human Embryonic Kidney cell line (293T) and culture in Glasgow&#39;s Minimum Essential Medium (GMEM), supplemented with 10% fetal calf serum (FCS), 1x non-essential amino acids, 1 mM sodium pyruvate and 1 mM glutamine at (see Table of Materials) 37 &#176;C and 5% CO2. 
	NOTE: It is recommended to use 293T cells within four passages post thawing.</li>
	<li>Seed 293T at a density of 3 million cells per 15 cm dish, 24 h before transfection. A total of three dishes are required. It is preferable to seed cells later in the afternoon ~16:00.</li>
	<li>Next day (~16:00), when cells reach ~40%-50% confluency, prepare the following for three transfection reactions: 
	NOTE: Always account for pipetting error by adding 10% volume extra.
	<ol>
		<li>Label three 15 mL plastic tubes with the appropriate lentivirus name (pSIN4-EF1a-O2S, pSIN4-CMV-K2M, and pwPT-GFP control). Add 1.710 mL reduced serum medium (see Table of Materials) to each tube.</li>
		<li>Dilute 90 &#181;L transfection reagent (see Table of Materials) in 1.710 mL reduced serum medium, mix by vertexing for 2 s, and incubate at room temperature for 5 min.</li>
		<li>Mix the packaging vectors; 5.1 &#181;g of psPAX2 and 2.4 &#181;g of pMDG (7.5 &#181;g total).</li>
		<li>Add the packaging vector mixture to the transfection medium (from step 1.4.2) and vortex for 2 s.</li>
		<li>Add 7.5 &#181;g of each reprogramming vector: pSIN4-EF1a-O2S and pSIN4-CMV-K2M and the pwPT-GFP control to the transfection mixture from step (1.4.4) and vortex for 2 s. 
		NOTE: Use the expression vector: viral vector at a 1:1 ratio.</li>
	</ol>
	</li>
	<li>Incubate the transfection tubes for 15 min at room temperature.</li>
	<li>Transfect the 293T cells with each lentivirus by directly adding the transfection-DNA mixture from step (1.4.5) to the media in a dropwise fashion. Swirl the dish to ensure even distribution across the entire surface.</li>
	<li>Incubate the transfected cells in a 37 &#176;C, 5% CO2 incubator overnight. 
	NOTE: Use virus-specific waste, a metal disposal bucket, double bag with autoclave bags, and take a liquid waste container for virus and add a disinfectant tablet. Dispose of all pipettes, tips, and tubes in a metal bucket. Dispose of old media into a virus-liquid waste container. Avoid using glass pipettes and glassware to eliminate accidental virus contamination.</li>
	<li>After 14-16 h post-transfection, replace the medium with 30 mL fresh 293T medium.</li>
	<li>Incubate the transfected cells at 37 &#176;C, 5% CO2 for 60-72 h post medium change. Observe cells daily and check transfection efficiency by GFP fluorescence. 
	NOTE: Ideally, transfection efficiency should be &#62;90% by GFP. For the other viruses, one should observe clear morphological changes of 293T cells, as they tend to become more round when producing virus particles.</li>
	<li>Collect the media from each virus transfection culture into 50 mL tubes and spin down to clear out cell debris at 1932 x g for 10 min at 4 &#176;C.</li>
	<li>Filter each lentivirus supernatant through a 0.45 &#181;M syringe filter to remove smaller debris and collect it into new 50 mL tubes.</li>
	<li>Divide each lentivirus supernatant into 6 mL aliquots and snap freeze each in liquid nitrogen.</li>
	<li>Store the lentivirus aliquots at -80 &#176;C until ready to use.</li>
</ol>
2. Reprogramming lentivirus transduction
<ol>
	<li>Thaw primary PDAC cells and culture in completely defined Keratinocyte Serum Free Medium (KSFM), supplemented with Bovine Pituitary Extract (BPE), human recombinant Epidermal Growth Factor (EGF) at 5 ng/mL, and Cholera toxin at 50 ng/mL in a 37 &#176;C, 5% CO2, and 5% O2 (hypoxia) incubator (see Table of Materials).</li>
	<li>Thaw BxPc3, a squamous pancreatic ductal adenocarcinoma cell line, and culture in RPMI 1640 medium supplemented with 10% fetal calf serum (FCS) at 37 &#176;C, and 5% CO2.</li>
	<li>Thaw H6C7 cells, pancreatic ductal epithelial cells, and culture in KSFM supplemented with BPE and EGF at 5 ng/mL, at 37 &#176;C and 5% CO2.</li>
	<li>Thaw Human fibroblast (hFib) and culture in Glasgow&#39;s Minimum Essential Medium (GMEM), supplemented with 10% FCS, 1x non-essential amino acids, 1 mM sodium pyruvate and 1 mM glutamine, and 0.05 mM (final) Beta-mercaptoethanol at 37 &#176;C and 5% CO2.</li>
	<li>One day prior to lentivirus transduction (preferably late afternoon), prepare two wells of a 6-well plate containing 100,000 cells per well of each of PDAC,BxPc3, H6C7, and hFib cells. Infect one well with OSKM lentiviruses and use the second as an uninfected control. 
	NOTE: Use a separate plate for each cell type.</li>
	<li>The following day, in the afternoon (approximately 24 h later), ensure that the cell confluency reaches at least 70% before proceeding to the next lentivirus infection step.</li>
</ol>
3. Lentivirus transduction of PDAC
<ol>
	<li>Defrost 5 mL of each lentivirus supernatant in a 37 &#176;C virus incubator.</li>
	<li>Prepare two 15 mL tubes, each containing 2 mL of pre-warmed PDAC culture medium.</li>
	<li>To the first tube, add 6&#160;mL of each reprogramming lentivirus (pSIN4-CMV-K2M and pSIN4-EF1a-O2S) and 12 &#181;L of 4.5 mg/mL polybrene (final 4.5 &#181;g/mL, see Table of Materials) and mix.</li>
	<li>To the second tube, add 2 &#181;L of 4.5 mg/mL polybrene (final 4.5 &#181;g/mL).</li>
	<li>Discard the medium from each well and wash once with PBS at room temperature.</li>
	<li>Add the reprogramming infection media (tube 1) to the first well.</li>
	<li>Add the mixture of tube 2 to the second well. This will be the uninfected control.</li>
	<li>Incubate the PDAC cells in a 37 &#176;C, 5% CO2, and 5% O2 (hypoxia) incubator overnight.</li>
	<li>Next day, in the afternoon, discard the media from both wells and replace it with fresh PDAC culture medium.</li>
	<li>Incubate the cells at 37 &#176;C, 5% CO2, and 5% O2 (hypoxia) for 48 h.</li>
</ol>
4. Lentivirus transduction of BxPc3 cells
<ol>
	<li>Defrost 3 mL of each lentivirus supernatant in a 37 &#176;C virus incubator.</li>
	<li>Prepare two 15 mL tubes, each containing 2 mL of BxPc3 culture medium.</li>
	<li>To the first tube, add 3 mL of each reprogramming lentivirus (pSIN4-CMV-K2M and pSIN4-EF1a-O2S) and 6&#160;&#181;L of 4.5 mg/mL polybrene (final 4.5 &#181;g/mL) and mix.</li>
	<li>To the second tube, add 2 &#181;L of 4.5 mg/mL polybrene (final 4.5 &#181;g/mL).</li>
	<li>Discard the medium from each well and wash once with PBS.</li>
	<li>Add the reprogramming infection media (tube 1) to the first well.</li>
	<li>Add the mixture of tube 2 to the second well. This will be the uninfected control.</li>
	<li>Incubate the infected BxPc3 cells at 37 &#176;C virus and 5% CO2 overnight.</li>
	<li>Next day, in the afternoon, discard the media from both wells and replace it with fresh BxPc3 culture medium.</li>
	<li>Incubate the cells at 37 &#176;C and 5% CO2 for 48 h.</li>
</ol>
5. Lentivirus transduction of H6c7 cells infection
<ol>
	<li>Defrost 4 mL of each lentivirus supernatant in a 37 &#176;C virus incubator.</li>
	<li>Prepare two 15 mL tubes, each containing 2 mL H6c7 culture medium.</li>
	<li>To the first tube, add 4 mL of each reprogramming lentivirus (pSIN4-CMV-K2M and pSIN4-EF1a-O2S) and 8 &#181;L of 4.5 mg/mL polybrene (final 4.5 &#181;g/mL) and mix.</li>
	<li>To the second tube, add 2 &#181;L of 4.5 mg/mL polybrene (final 4.5 &#181;g/mL).</li>
	<li>Discard the medium from both wells and wash once with PBS.</li>
	<li>Add the reprogramming infection media (tube 1) to the first well.</li>
	<li>Add the mixture of tube 2 to the second well. This will be the uninfected control.</li>
	<li>Incubate the infected H6C7 cells at 37 &#176;C virus and 5% CO2 overnight.</li>
	<li>Next day, in the afternoon, discard the media from both wells and replace them with a fresh H6c7 culture medium.</li>
	<li>Incubate the cells at 37 &#176;C and 5% CO2 for 48 h.</li>
</ol>
6. Lentivirus transduction of hFib cells
<ol>
	<li>Defrost 2 mL of each lentivirus supernatant in a 37 &#176;C virus incubator.</li>
	<li>Prepare two 15 mL tubes, each containing 2 mL hFib culture medium.</li>
	<li>To the first tube, add 2 mL of each reprogramming viruses (pSIN4-CMV-K2M and pSIN4-EF1a-O2S) and add 4 &#181;L of 4.5 mg/mL polybrene (final 4.5 &#181;g/mL) and mix.</li>
	<li>To the second tube, add 2 &#181;L of 4.5 mg/mL polybrene (final 4.5 &#181;g/mL) and mix.</li>
	<li>Discard the medium from each well and wash once with PBS.</li>
	<li>Add the reprogramming infection media (tube 1) to the first well.</li>
	<li>Add the mixture of tube 2 to the second well. This will be the uninfected control.</li>
	<li>Incubate the infected hFib cells at 37 &#176;C and 5% CO2 overnight.</li>
	<li>Next day, in the afternoon, discard the media from both wells and replace it with fresh hFib culture medium.</li>
	<li>Incubate the cells at 37 &#176;C and 5% CO2 for a further 48 h. 
	NOTE: For efficient lentivirus transduction, titer the amount of lentivirus carefully,&#160;as this varies greatly between the different cell types. Multiple lentivirus transductions may be required for some cell types. PDAC cell lines require up to three doses, whereas one dose was enough for reprogramming BxPc3, H6C7, and hFib lines.</li>
</ol>
7. Preparation of iMEF feeder cells
<ol>
	<li>Prepare 40 mL 0.2% gelatine solution by diluting 1% gelatine stock solution with PBS.</li>
	<li>Coat four 6-well plates by covering each well with 2 mL of 0.2% gelatine solution.</li>
	<li>Incubate the gelatine-coated plates at 37 &#176;C and 5% CO2 for at least 30 min.</li>
	<li>Aspirate the excess gelatine solution and leave the plates to dry under the flow hood.</li>
	<li>Thaw two vials (~ 4 million cells per vial) of irradiated mouse embryonic fibroblast (iMEFs) by swirling it in a 37 &#176;C water bath. 
	NOTE: To reduce the possibility of contamination, be careful to prevent water from splashing near the cap opening. Dry the vial with a paper towel and spray it with 70% ethanol.</li>
	<li>In the tissue culture hood, pipette the content of each thawed iMEFs vial into one 15 mL tube containing 10 mL of pre-warmed hFib culture medium in a dropwise fashion and mix well by gently inverting the tube.</li>
	<li>Spin down the cell suspension at 309 x g for 3 min at room temperature and remove the supernatant from each tube. Resuspend each cell pellet in 12 mL hFib medium.</li>
	<li>Plate 2 mL of the cell suspension per well of the gelatine-coated 6-well plates. Evenly distribute the cells by gently shaking the plates in all directions.</li>
	<li>Incubate the plates at 37 &#176;C and 5% CO2 overnight. 
	NOTE: Prepare fresh iMEF plates 24 h before being used for the reprogramming experiment.</li>
</ol>
8. Transferring the infected cells onto the iMEF feeder layer
<ol>
	<li>Discard media from the infected and non-infected PDAC, BxPc3, H6c7, and hFib cells. Wash each well twice with PBS at room temperature.</li>
	<li>Dissociate the cells from the plate by adding 0.5 mL of trypsin to each well. Incubate PDAC cells in a 37 &#176;C, 5% CO2, and 5% O2 (hypoxia) incubator for 15 min.</li>
	<li>Incubate BxPc3 cells at 37 &#176;C and 5% CO2 for 5 min.</li>
	<li>Incubate H6c7 and hFib cells at 37 &#176;C and 5% CO2 for 4 min.</li>
	<li>Transfer the dissociated cell suspension from each well into 15 mL tubes labeled accordingly as infected or uninfected.</li>
	<li>Harvest the cells by centrifugation as follows: for PDAC, spin the cell suspension at 300 x g for 5 min; for BxPc3, spin the cell suspension at 120 x g for 5 min; for H6C7, spin the cell suspension at 112 x g for 4 mins; for hFib, spin the cell suspension at 161 x g for 3 min. Perform all the centrifugations at room temperature.</li>
	<li>Resuspend each cell type pellet in 1 mL of the appropriate culture media.</li>
	<li>Wash iMEF plates prepared in step 7 with each cell type culture media twice. i.e., wash one plate with PDAC media, one with BxPc3 media, one with H6C7 medium, and the other with hFib medium.</li>
	<li>Plate 50,000 infected cells per well in five wells of iMEF 6-well plate. Plate 50,000 uninfected control cells in the remaining one well of iMEF 6-well plate. 
	NOTE: Optimise the number of infected cells to be plated from 1,000 to 50,000 cells per well.</li>
	<li>Incubate PDAC cells at 37 &#176;C, 5% CO2, and 5% O2 (hypoxia) overnight.</li>
	<li>Incubate BxPc3, H6C7, and hFib cells at 37 &#176;C and 5% CO2 overnight.</li>
	<li>Next day, prepare reprogramming medium as follows: add 100 mL knockout serum replacement (25% final), 5 mL of 200 mM glutamine (1 mM final), 5 mL of 100x non-essential amino acids (100 &#181;M final), 1.5 mL of Beta-mercaptoethanol (0.1 mM final) to 400 mL Modified Eagle Medium (DMEM).</li>
	<li>Store the reprogramming media in 100 mL aliquots at 4 &#176;C for up to 4 weeks or at -20 &#176;C for longer.</li>
	<li>When ready to use, add 100 &#181;L of 10 mg/mL basic fibroblast growth factor (bFGF) (10 ng/mL final) to one 100 mL reprogramming media aliquot.</li>
	<li>Warm the reprogramming media in a 37 &#176;C water bath.</li>
	<li>Wash the cells growing on iMEFs feeders with pre-warmed reprogramming media twice. 
	Add 2 mL of reprogramming medium to each well.</li>
	<li>Transfer the reprogramming plates into a 37 &#176;C, 5% CO2and 3% O2 (hypoxia) incubator. 
	NOTE: The day when reprogramming media is added is considered day 1 of reprogramming.</li>
	<li>Feed the cells daily with fresh reprogramming media until iPSC colonies start to appear. 
	NOTE: Identify iPSC colonies by their ESC-like morphology (compact colonies with well-defined edges and comprised of cells with a high nucleus/cytoplasm ratio).</li>
	<li>Monitor the iPSC colonies daily, and after an adequate number have been formed, passage them as a pool. 
	NOTE: Ensure that the iPSC colonies do not touch each other, as this would result in differentiation and affect their long-term stability.</li>
	<li>To establish clonal lines, passage the iPSC pool about 5 times, then pick robust colonies that maintain their ESC-like morphology.</li>
	<li>To identify fully reprogrammed iPSC colonies, carry out live staining with TRA-160 (see Table of Materials), and harvest RNA from iPSC colonies for gene expression characterization.</li>
</ol>
9. Passaging of iPSC colonies
<ol>
	<li>Prepare enough iMEF feeder plates 24 h before passaging the iPSC colonies as described in step 7.</li>
	<li>Wash iMEF feeder plates twice with pre-warmed reprogramming media.</li>
	<li>Add 2 mL of reprogramming media supplemented with ROCK inhibitor (Y2) (10 &#181;M) to each well of iMEF plate.</li>
	<li>Incubate the iMEF plates in a 37 &#176;C, 5% CO2, and 3% O2 incubator until ready to use.</li>
	<li>Prepare Ethylenediaminetetraacetic acid/ Phosphate Buffered Saline (EDTA/PBS) solution by diluting 0.5 M EDTA 1:1000 in PBS (0.5 mM final).</li>
	<li>Replace the reprogramming culture media with 0.5 mL of EDTA/PBS in each well.</li>
	<li>Incubate in a 37 &#176;C, 5% CO2, and 3% O2 incubator or at room temperature, depending on the cell type. BxPc3 and PDAC iPSCs require 15 min incubation at 37 &#176;C. H6C7 and hFib iPSCs need to be incubated at room temperature for 5 min.</li>
	<li>Check the iPSCs cells under the microscope until they begin to uniformly dissociate from the feeder layer throughout the entire colony.</li>
	<li>Collect the dissociated iPSC cell suspension into a 15 mL centrifuge tube. Spin down at 300 x g for 5 min at room temperature.</li>
	<li>Resuspend the cell pellet in 1 mL of reprogramming media supplemented with Y2 (10 &#181;M).</li>
	<li>Plate the cells on iMEF feeder layer by transferring each 1 mL of iPSC cell suspension to three wells of the iMEF plate. 
	NOTE: The split ratio may vary depending on the number of harvested iPSC colonies.</li>
	<li>Incubate in a 37 &#176;C, 5% CO2 and 3% O2 incubator.</li>
</ol>
10. Live staining of iPSC colonies with TRA-1-60
<ol>
	<li>Prepare 0.5 mL per well of 4 &#181;g/mL TRA-1-60 antibody in reprogramming media.</li>
	<li>Discard reprogramming media and replace it with 0.5 mL antibody mixture in each well. Incubate in a 37 &#176;C, 5% CO2, and 3% O2 incubator for 30 min.</li>
	<li>Wash the cells twice with the reprogramming media.</li>
	<li>Capture fluorescence images with a cell imaging system using the GFP filter.</li>
	<li>Check the image quality by considering the negative control channel.</li>
</ol>

Reprogramming PDAC and Pancreatic Cells into Induced Pluripotent Stem Cells

The authors declare no conflict of interest.

To facilitate the use of iPSC reprogramming for studying cancer progression, a robust protocol has been established for reprogramming pancreatic cancer cells. Reprogramming cancer cells into pluripotency has proven to be very challenging thus far, as only a few studies have successfully generated iPSCs from cancer cells32,36,37,38,39,<sup class="xre...

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal malignancies, and early diagnosis remains challenging due to the asymptomatic nature of the disease. The majority of PDAC patients are diagnosed at the advanced metastatic stage when very limited treatment options are available1,2. This is mainly due to the lack of reliable biomarkers for the earlier stages, such as those that could be conveniently detected as proteins released into the bloodstream.
PDAC can disseminate very early during its progression, and a better prognosis has been linked to early cancer detection when PDAC is localized in the pancreas3. However, less than a tenth of PDAC patients are diagnosed with a favorable prognosis, allowing for surgical resection. Nonetheless, those few with resectable tumors are also prone to tumor recurrence within 12 months4.
In the past five decades, remarkable improvements have been made in surgical techniques, patient care, and treatment modalities5,6. However, the 5-year survival rate in surgically resected PDAC patients has barely risen to 17%. Nonetheless, this is still better than that in non-resected patients, which has remained almost unchanged (0.9%)4,7. Chemotherapy is the only other alternative PDAC treatment. Yet, this option is very limited as the great majority of PDAC patients exhibit strong resistance to chemotherapy medications such as Gemcitabine7,8. Other drugs, such as Erlotinib, are only available to a small group of PDAC patients with specific mutations, most of whom show Erlotinib resistance9. The adverse side effects associated with chemotherapy in most PDAC patients are yet another disadvantage of this treatment10. Recently, promising strategies have shown that immune checkpoint inhibitors (ICIs) and small molecule kinase inhibitors (SMKIs) can be effective in treating PDAC, but durable responses to these targeted therapies remain limited to a minority of patients11,12. Overall, the discovery of PDAC-specific early biomarkers can pave new avenues for early diagnosis and treatment.
PDAC develops from pancreatic intraepithelial neoplasms (PanIN) precursor lesions that result from non-invasive pancreatic duct epithelial proliferations13,14. While the formation of PanIN is initiated by oncogene mutations such as KRAS, additional genetic and epigenetic alterations are required for the progression to PDAC. It has been projected that the progression of PanIN through the different stages into invasive PDAC takes about 10 years13,15,16,17. This timeframe provides a great opportunity to benefit from early PDAC diagnosis. Therefore, extensive research has been carried out to establish tumor xenograft animal models and organoid cultures to study PDAC progression18,19,20,21. These models have been very useful for studying the invasive stages of PDAC, although not the transition from the early PanIN phases. It is, therefore, important to develop experimental models that can recapitulate the early progression of PanIN stages to enable the discovery of early detection biomarkers.
Reprogramming somatic cells into induced pluripotent stem cells (iPSCs) using the four transcription factors OCT4, SOX2, KLF4, and c-MYC (OSKM) has illustrated the extent of cellular plasticity22. Cancer cell plasticity has been well-documented, and reprogramming human cancer cells into iPSCs has been successfully used to reset cells to their original cellular state, removing many of the epigenetic insults that have accumulated during cancer progression23,24,25,26,27,28,29. The possibility of using this reprogramming strategy to manipulate cancer cell identity has, therefore, presented great promise in treating cancer30,31. Indeed, we have previously shown that the differentiation of iPSCs derived from PDACs can recapitulate PDAC progression through the early PanIN stages32. By identifying genes and pathways specific to the early-to-intermediate stages of PDAC, candidate biomarkers were identified that can be clinically used for early PDAC diagnosis32,33. However, the biomarkers discovered using a single iPSC line showed limited coverage in the majority of PDAC patients32. The challenges of generating iPSC lines from other PDAC patients have halted the ability to discover more reliable biomarkers. This is due to many technical factors, including the heterogeneity of OSKM delivery, as only a small portion of human primary PDAC cells contained all four factors and responded successfully to reprogramming. Here, a detailed protocol is presented for reprogramming primary PDAC cells using a more efficient and consistent dual lentiviral delivery of OSKM.

<table><tbody><tr><td>2-Mercaptoethanol (50 mM)</td><td>Thermo Fisher</td><td>31350010</td><td></td></tr><tr><td>Alexa Fluor 488 anti- human TRA-1-60-R</td><td>BioLegend</td><td>330613</td><td></td></tr><tr><td>Bovine Pituitary Extract (BPE)</td><td>Thermo Fisher</td><td>13028014</td><td></td></tr><tr><td>BxPc3</td><td>ATCC</td><td>CRL-1687</td><td></td></tr><tr><td>Cholera Toxin from Vibrio cholerae</td><td>Merck&amp;nbsp;</td><td>C8052-1MG</td><td></td></tr><tr><td>Collagen, Type I solution from rat tail</td><td>Merck&amp;nbsp;</td><td>C3867</td><td></td></tr><tr><td>Completed Defined K-SFM</td><td>Thermo Fisher</td><td>&amp;nbsp;10744-019</td><td></td></tr><tr><td>Corning Costar TC-Treated Multiple Well Plates</td><td>Merck&amp;nbsp;</td><td>CLS3516</td><td></td></tr><tr><td>Corning syringe filters</td><td>Merck&amp;nbsp;</td><td>CLS431231</td><td></td></tr><tr><td>Corning tissue-culture treated culture dishes</td><td>Merck&amp;nbsp;</td><td>CLS430599</td><td></td></tr><tr><td>Day Impex&amp;nbsp;Virkon Disinfectant Virucidal Tablets</td><td>Thermo Fisher</td><td>12328667</td><td></td></tr><tr><td>Dulbecco&amp;prime;s Phosphate Buffered Saline (PBS)</td><td>Merck&amp;nbsp;</td><td>D8537</td><td></td></tr><tr><td>Fetal Calf Serum (FCS)&amp;nbsp;</td><td>Thermo Fisher</td><td>10270-106</td><td></td></tr><tr><td>Fugene HD Transfection Reagent&amp;nbsp;</td><td>Promega&amp;nbsp;</td><td>&amp;nbsp;E2312</td><td></td></tr><tr><td>Gelatin solution, Type B, 2% in H&lt;sub&gt;2&lt;/sub&gt;O</td><td>Merck&amp;nbsp;</td><td>G1393-100ML</td><td></td></tr><tr><td>Glasgow Minimum Essential Media (GMEM)</td><td>Merck&amp;nbsp;</td><td>G5154</td><td></td></tr><tr><td>Human EGF Recombinant Protein</td><td>Thermo Fisher</td><td>PHG0311</td><td></td></tr><tr><td>Human FGF-basic (FGF-2/bFGF) (154 aa) Recombinant Protein, PeproTech</td><td>Thermo Fisher</td><td>100-18B</td><td></td></tr><tr><td>Human Pancreatic Duct Epithelial Cell Line (H6c7)</td><td>Kerafast</td><td>ECA001-FP</td><td></td></tr><tr><td>iMEF feeder cells&amp;nbsp;</td><td>iXcells Biotechnologies</td><td>10MU-001-1V</td><td></td></tr><tr><td>Keratinocyte Serum Free Media (KSFM)&amp;nbsp;</td><td>Thermo Fisher</td><td>17005-042</td><td></td></tr><tr><td>KnockOut DMEM&amp;nbsp;</td><td>Thermo Fisher</td><td>10829018</td><td></td></tr><tr><td>KnockOut serum Replacement&amp;nbsp;</td><td>Thermo Fisher</td><td>10828028</td><td></td></tr><tr><td>L-Glutamine (200 mM)</td><td>Thermo Fisher</td><td>25030-024</td><td></td></tr><tr><td>MEM Non-Essential Amino Acids Solution (100x)</td><td>Thermo Fisher</td><td>11140050</td><td></td></tr><tr><td>Millex-HP 0.45 &amp;mu;M syringe Filter Unit (Sterile)</td><td>Merck&amp;nbsp;</td><td>SLHP033RS</td><td></td></tr><tr><td>Opti-MEM Reduced Serum Medium&amp;nbsp;</td><td>Thermo Fisher</td><td>31985062</td><td></td></tr><tr><td>pMDG&amp;nbsp;</td><td>AddGene</td><td>187440</td><td></td></tr><tr><td>Polybrene (Hexadimethrine bromide)&amp;nbsp;</td><td>Merck&amp;nbsp;</td><td>H9268-5G</td><td></td></tr><tr><td>pSIN4-CMV-K2M&amp;nbsp;</td><td>AddGene</td><td>21164</td><td></td></tr><tr><td>pSIN4-EF2-O2S&amp;nbsp;</td><td>AddGene</td><td>21162</td><td></td></tr><tr><td>psPAX2</td><td>AddGene</td><td>12260</td><td></td></tr><tr><td>pWPT-GFP&amp;nbsp;</td><td>AddGene</td><td>12255</td><td></td></tr><tr><td>RPMI 1640 Medium (ATCC modification)</td><td>Thermo Fisher</td><td>A1049101</td><td></td></tr><tr><td>Sodym Pyruvate</td><td>Thermo Fisher</td><td>11360-039</td><td></td></tr><tr><td>Sterile Syringes for Single Use (60 mL)&amp;nbsp;</td><td>Thermo Fisher</td><td>15899152</td><td></td></tr><tr><td>TrypLE Express Enzyme (1x), phenol red</td><td>Thermo Fisher</td><td>12605036</td><td></td></tr><tr><td>UltraPure 0.5M EDTA, pH 8.0</td><td>Thermo Fisher</td><td>15575020</td><td></td></tr><tr><td>Y-27632 (Dihydrochloride)</td><td>STEMCELL Technologies</td><td>72304</td><td></td></tr></tbody></table>

reprogramming pancreatic ductal adenocarcinoma to pluripotency

The generation of induced pluripotent stem cells (iPSCs) using transcription factors has been achieved from almost any differentiated cell type and has proved highly valuable for research and clinical applications. Interestingly, iPSC reprogramming of cancer cells, such as pancreatic ductal adenocarcinoma (PDAC), has been shown to revert the invasive PDAC phenotype and override the cancer epigenome. The differentiation of PDAC-derived iPSCs can recapitulate PDAC progression from its early pancreatic intraepithelial neoplasia (PanIN) precursor, revealing the molecular and cellular changes that occur early during PDAC progression. Therefore, PDAC-derived iPSCs can be used to model the earliest stages of PDAC for the discovery of early-detection diagnostic markers. This is particularly important for PDAC patients, who are typically diagnosed at the late metastatic stages due to a lack of reliable biomarkers for the earlier PanIN stages. However, reprogramming cancer cell lines, including PDAC, into pluripotency remains challenging, labor-intensive, and highly variable between different lines. Here, we describe a more consistent protocol for generating iPSCs from various human PDAC cell lines using bicistronic lentiviral vectors. The resulting iPSC lines are stable, showing no dependence on the exogenous expression of reprogramming factors or inducible drugs. Overall, this protocol facilitates the generation of a wide range of PDAC-derived iPSCs, which is essential for discovering early biomarkers that are more specific and representative of PDAC cases.

Representative images displaying the morphology of iPSC colonies derived from PDAC, BXPc3, H6C7, and hFib cells are shown in Figure 1. PDAC-iPSC colonies started to form on Day 25 of reprogramming. Robust iPSC colonies with a more established ESC-like morphology were identified on Day 40 of reprogramming (Figure 1). Similarly, the formation of BxPc3-iPSCs began on Day 23 and became more established by Day 35. H6C7-iPSC formation ...

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Author Spotlight: Reprogramming Cancer Cells to iPSCs to Study Disease Progression and Treatment Targets

The present protocol describes the reprogramming of Pancreatic Ductal Adenocarcinoma (PDAC) and normal pancreatic ductal epithelial cells into induced pluripotent stem cells (iPSCs). We provide an optimized and detailed, step-by-step procedure, from preparing lentivirus to establishing stable iPSC lines.

Reprogramming Pancreatic Ductal Adenocarcinoma to Pluripotency

The generation of induced pluripotent stem cells (iPSCs) using transcription factors has been achieved from almost any differentiated cell type and has ...

reprogramming-pancreatic-ductal-adenocarcinoma-to-pluripotency

Research

JoVE Journal

Cancer Research

705 Views.  The University of Edinburgh. 1 Een van de meest uitdagende aspecten van het bestuderen van PDAC2 of alvleesklierkanker is de beschikbaarheid 3 van een experimenteel model 4 dat de progressie 5 van PDAC van de vroege prolinestadia 6 tot de agressieve toestand kan samenvatten. 7 De andere uitdaging is om experimenteel 8 de plasticiteit en heterogeniteit van PDAC vast te leggen. 9 Dus het gebruik van PDAC IPS-cellen zal ons helpen om 10 enkele van deze uitdagingen aan te pakken 11 en onz...

Video: Auteur in de schijnwerpers: kankercellen herprogrammeren naar iPSC's om ziekteprogressie en behandelingsdoelen te bestuderen

Mimicking and Manipulating Pancreatic Acinar-to-Ductal Metaplasia in 3-dimensional Cell Culture

The differentiation of acinar cells to ductal cells during pancreatitis and in the early development of pancreatic cancer is a key process that requires further study. To understand the mechanisms regulating acinar-to-ductal metaplasia (ADM), ex vivo 3D culture and differentiation of primary acinar cells to ductal cells offers many advantages over other systems. With the technique herein, modulation of protein expression is simple and quick, requiring only one day to isolate, stimulate or virally infect, and begin culturing primary acinar cells to investigate the ADM process. In contrast to using basement membrane matrix, the seeding of acinar cell clusters in collagen I extracellular matrix, allows acinar cells to retain their acinar identity before manipulation. This is vital when testing the contribution of various components to the induction of ADM. Not only are the effects of cytokines or other ectopically administered factors testable through this technique, but the contribution of common mutations, increased protein expression, or knockdown of protein expression is testable via viral infection of primary acinar cells, using adenoviral or lentiviral vectors. Moreover, cells can be re-isolated from collagen or basement membrane matrix at the endpoint and analyzed for protein expression.

Primary acinar cell isolation, protein expression or activity modulation, culture, and down-stream applications are abundantly useful in the ex vivo study of acinar-to-ductal metaplasia (ADM), an early event in the development of pancreatic cancer.

The differentiation of acinar cells to ductal cells during pancreatitis and in the early development of pancreatic cancer is a key process that requires ...

Efficient Differentiation of Pluripotent Stem Cells to NKX6-1+ Pancreatic Progenitors

Pluripotent stem cells have the ability to self renew and differentiate to multiple lineages, making them an attractive source for the generation of pancreatic progenitor cells that can be used for the study of and future treatment of diabetes. This article outlines a four-stage differentiation protocol designed to generate pancreatic progenitor cells from human embryonic stem cells (hESCs). This protocol can be applied to a number of human pluripotent stem cell (hPSC) lines. The approach taken to generate pancreatic progenitor cells is to differentiate hESCs to accurately model key stages of pancreatic development. This begins with the induction of the definitive endoderm, which is achieved by culturing the cells in the presence of Activin A, basic Fibroblast Growth Factor (bFGF) and CHIR990210. Further differentiation and patterning with Fibroblast Growth Factor 10 (FGF10) and Dorsomorphin generates cells resembling the posterior foregut. The addition of Retinoic Acid, NOGGIN, SANT-1 and FGF10 differentiates posterior foregut cells into cells characteristic of pancreatic endoderm. Finally, the combination of Epidermal Growth Factor (EGF), Nicotinamide and NOGGIN leads to the efficient generation of PDX1+/NKX6-1+ cells. Flow cytometry is performed to confirm the expression of specific markers at key stages of pancreatic development. The PDX1+/NKX6-1+ pancreatic progenitors at the end of stage 4 are capable of generating mature &#946; cells upon transplantation into immunodeficient mice and can be further differentiated to generate insulin-producing cells in vitro. Thus, the efficient generation of PDX1+/NKX6-1+ pancreatic progenitors, as demonstrated in this protocol, is of great importance as it provides a platform to study human pancreatic development in vitro and provides a source of cells with the potential of differentiating to &#946; cells that could eventually be used for the treatment of diabetes.

Efficient Differentiation of Pluripotent Stem Cells to NKX6-1+ Pancreatic Progenitors

Here we describe a 4-stage protocol to differentiate human embryonic stem cells to NKX6-1+ pancreatic progenitors in vitro. This protocol can be applied to a variety of human pluripotent stem cell lines.

Pluripotent stem cells have the ability to self renew and differentiate to multiple lineages, making them an attractive source for the generation of ...

Developmental Biology

Isolation and Characterization of Patient-derived Pancreatic Ductal Adenocarcinoma Organoid Models

Pancreatic ductal adenocarcinoma (PDAC) is amongst the most lethal malignancies. Recently, next-generation organoid culture methods enabling the 3-dimensional (3D) modeling of this disease have been described. Patient-derived organoid (PDO) models can be isolated from both surgical specimens as well as small biopsies and form rapidly in culture. Importantly, organoid models preserve the pathogenic genetic alterations detected in the patient&#39;s tumor and are predictive of the patient&#39;s treatment response, thus enabling translational studies. Here, we provide comprehensive protocols for adapting tissue culture workflow to study 3D, matrix embedded, organoid models. We detail methods and considerations for isolating and propagating primary PDAC organoids. Furthermore, we describe how bespoke organoid media is prepared and quality controlled in the laboratory. Finally, we describe assays for downstream characterization of the organoid models such as isolation of nucleic acids (DNA and RNA), and drug testing. Importantly we provide critical considerations for implementing organoid methodology in a research laboratory.

Patient-derived organoid cultures of pancreatic ductal adenocarcinoma are a rapidly established 3-dimensional model that represent epithelial tumor cell compartments with high fidelity, enabling translational research into this lethal malignancy. Here, we provide detailed methods to establish and propagate organoids as well as to perform relevant biological assays using these models.

Pancreatic ductal adenocarcinoma (PDAC) is amongst the most lethal malignancies. Recently, next-generation organoid culture methods enabling the ...

Reprogramming Primary Amniotic Fluid and Membrane Cells to Pluripotency in Xeno-free Conditions

Autologous cell-based therapies got a step closer to reality with the introduction of induced pluripotent stem cells. Fetal stem cells, such as amniotic fluid and membrane mesenchymal stem cells, represent a unique type of undifferentiated cells with promise in tissue engineering and for reprogramming into iPSC for future pediatric interventions and stem cell banking. The protocol presented here describes an optimized procedure for extracting and culturing primary amniotic fluid and membrane mesenchymal stem cells and generating episomal induced pluripotent stem cells from these cells in fully chemically defined culture conditions utilizing human recombinant vitronectin and the E8 medium. Characterization of the new lines by applying stringent methods &#8211; flow cytometry, confocal imaging, teratoma formation and transcriptional profiling &#8211; is also described. The newly generated lines express markers of embryonic stem cells &#8211; Oct3/4A, Nanog, Sox2, TRA-1-60, TRA-1-81, SSEA-4 &#8211; while being negative for the SSEA-1 marker. The stem cell lines form teratomas in scid-beige mice in 6-8 weeks and the teratomas contain tissues representative of all three germ layers. Transcriptional profiling of the lines by submitting global expression microarray data to a bioinformatic pluripotency assessment algorithm deemed all lines pluripotent and therefore, this approach is an attractive alternative to animal testing. The new iPSC lines can readily be used in downstream experiments involving the optimization of differentiation and tissue engineering.

This protocol describes the reprogramming of primary amniotic fluid and membrane mesenchymal stem cells into induced pluripotent stem cells using a non-integrating episomal approach in fully chemically defined conditions. Procedures of extraction, culture, reprogramming, and characterization of the resulting induced pluripotent stem cells by stringent methods are detailed.

Autologous cell-based therapies got a step closer to reality with the introduction of induced pluripotent stem cells. Fetal stem cells, such as amniotic ...

Efficient Generation of Pancreas/Duodenum Homeobox Protein 1+ Posterior Foregut/Pancreatic Progenitors from hPSCs in Adhesion Cultures

Human pluripotent stem cell (hPSC)-derived pancreatic cells are a promising cell source for regenerative medicine and a platform to study human developmental processes. Stepwise directed differentiation that recapitulates developmental processes is one of the major ways to generate pancreatic cells including pancreas/duodenum homeobox protein 1+ (PDX1+) pancreatic progenitor cells. Conventional protocols initiate the differentiation with small colonies shortly after the passage. However, in the state of colonies or aggregates, cells are prone to heterogeneities, which might hamper the differentiation to PDX1+ cells. Here, we present a detailed protocol to differentiate hPSCs into PDX1+ cells. The protocol consists of four steps and initiates the differentiation by seeding dissociated single cells. The induction of SOX17+ definitive endoderm cells was followed by the expression of two primitive gut tube markers, HNF1&#946; and HNF4&#945;, and eventual differentiation into PDX1+ cells. The present protocol provides easy handling and may improve and stabilize the differentiation efficiency of some hPSC lines that were previously found to differentiate inefficiently into endodermal lineages or PDX1+ cells.

Efficient Generation of Pancreas/Duodenum Homeobox Protein 1+ Posterior Foregut/Pancreatic Progenitors from hPSCs in Adhesion Cultures

Here, we present a detailed protocol to differentiate human pluripotent stem cells (hPSCs) into pancreas/duodenum homeobox protein 1+ (PDX1+) cells for the generation of pancreatic lineages based on the non-colony type monolayer growth of dissociated single cells. This method is suitable for producing homogenous hPSC-derived cells, genetic manipulation and screening.

Human pluripotent stem cell (hPSC)-derived pancreatic cells are a promising cell source for regenerative medicine and a platform to study human ...

RNA-based Reprogramming of Human Primary Fibroblasts into Induced Pluripotent Stem Cells

Induced pluripotent stem cells (iPSCs) have proven to be a valuable tool to study human development and disease. Further advancing iPSCs as a regenerative therapeutic requires a safe, robust, and expedient reprogramming protocol. Here, we present a clinically relevant, step-by-step protocol for the extremely high-efficiency reprogramming of human dermal fibroblasts into iPSCs using a non-integrating approach. The core of the protocol consists of expressing pluripotency factors (SOX2, KLF4, cMYC, LIN28A, NANOG, OCT4-MyoD fusion) from in vitro transcribed messenger RNAs synthesized with modified nucleotides (modified mRNAs). The reprogramming modified mRNAs are transfected into primary fibroblasts every 48 h together with mature embryonic stem cell-specific microRNA-367/302 mimics for two weeks. The resulting iPSC colonies can then be isolated and directly expanded in feeder-free conditions. To maximize efficiency and consistency of our reprogramming protocol across fibroblast samples, we have optimized various parameters including the RNA transfection regimen, timing of transfections, culture conditions, and seeding densities. Importantly, our method generates high-quality iPSCs from most fibroblast sources, including difficult-to-reprogram diseased, aged, and/or senescent samples.

Here we describe a clinically relevant, high-efficiency, feeder-free method to reprogram human primary fibroblasts into induced pluripotent stem cells using modified mRNAs encoding reprogramming factors and mature microRNA-367/302 mimics. Also included are methods to assess reprogramming efficiency, expand clonal iPSC colonies, and confirm expression of the pluripotency marker TRA-1-60.

Induced pluripotent stem cells (iPSCs) have proven to be a valuable tool to study human development and disease. Further advancing iPSCs as a regenerative ...

Differentiation of Human Pluripotent Stem Cells Into Pancreatic Beta-Cell Precursors in a 2D Culture System

Human pluripotent stem cells (hPSCs) are an excellent tool for studying early pancreatic development and investigating the genetic contributors to diabetes. hPSC-derived insulin-secreting cells can be generated for cell therapy and disease modeling,&#160;however,&#160;with limited efficiency and functional properties. hPSC-derived pancreatic progenitors that are precursors to beta cells and other endocrine cells, when co-express the two transcription factors PDX1 and NKX6.1, specify the progenitors to functional, insulin-secreting beta cells both in vitro and in vivo. hPSC-derived pancreatic progenitors are currently used for cell therapy in type 1 diabetes patients as part of clinical trials. However, current procedures do not generate a high proportion of NKX6.1 and pancreatic progenitors, leading to co-generation of non-functional endocrine cells and few glucose-responsive, insulin-secreting cells. This work thus developed an enhanced protocol for generating hPSC-derived pancreatic progenitors that maximize the co-expression of PDX1 and NKX6.1 in a 2D monolayer. The factors such as cell density, availability of fresh matrix, and dissociation of hPSC-derived endodermal cells are modulated that augmented PDX1 and NKX6.1 levels in the generated pancreatic progenitors and minimized commitment to alternate hepatic lineage. The study highlights that manipulating the cell&#39;s physical environment during in vitro differentiation can impact lineage specification and gene expression. Therefore, the current optimized protocol facilitates the scalable generation of PDX1 and NKX6.1 co-expressing progenitors for cell therapy and disease modeling.

The present protocol describes an enhanced method to increase the co-expression of PDX1 and NKX6.1 transcription factors in pancreatic progenitors derived from human pluripotent stem cells (hPSCs) in planar monolayers. This is achieved by replenishing the fresh matrix, manipulating cell density, and dissociating the endodermal cells.

Human pluripotent stem cells (hPSCs) are an excellent tool for studying early pancreatic development and investigating the genetic contributors to ...

Surgical Injury to the Mouse Pancreas through Ligation of the Pancreatic Duct as a Model for Endocrine and Exocrine Reprogramming and Proliferation

Expansion of pancreatic beta cells in vivo or ex vivo, or generation of beta cells by differentiation from an embryonic or adult stem cell, can provide new expandable sources of beta cells to alleviate the donor scarcity in human islet transplantation as therapy for diabetes. Although recent advances have been made towards this aim, mechanisms that regulate beta cell expansion and differentiation from a stem/progenitor cell remain to be characterized. Here, we describe a protocol for an injury model in the adult mouse pancreas that can function as a tool to study mechanisms of tissue remodeling and beta cell proliferation and differentiation. Partial duct ligation (PDL) is an experimentally induced injury of the rodent pancreas involving surgical ligation of the main pancreatic duct resulting in an obstruction of drainage of exocrine products out of the tail region of the pancreas. The inflicted damage induces acinar atrophy, immune cell infiltration and severe tissue remodeling. We have previously reported the activation of Neurogenin (Ngn) 3 expressing endogenous progenitor-like cells and an increase in beta cell proliferation after PDL. Therefore, PDL provides a basis to study signals involved in beta cell dynamics and the properties of an endocrine progenitor in adult pancreas. Since, it still remains largely unclear, which factors and pathways contribute to beta cell neogenesis and proliferation in PDL, a standardized protocol for PDL will allow for comparison across laboratories.

This protocol describes an injury model involving the surgical ligation of the pancreatic duct in the adult mouse pancreas, resulting in severe injury that establishes an environment that allows beta cell neogenesis and proliferation. This model can be used as a tool to study mechanisms involved in beta cell formation.

Expansion of pancreatic beta cells in vivo or ex vivo, or generation of beta cells by differentiation from an embryonic or adult stem cell, can provide ...

Medicine

In vitro Induction of Human Dental Pulp Stem Cells Toward Pancreatic Lineages

As of 2000, the success of pancreatic islet transplantation using the Edmonton protocol to treat type I diabetes mellitus still faced some obstacles. These include the limited number of cadaveric pancreas donors and the long-term use of immunosuppressants. Mesenchymal stem cells (MSCs) have been considered to be a potential candidate as an alternative source of islet-like cell generation. Our previous reports have successfully illustrated the establishment of induction protocols for differentiating human dental pulp stem cells (hDPSCs) to insulin-producing cells (IPCs). However, the induction efficiency varied greatly. In this paper, we demonstrate the comparison of hDPSCs pancreatic induction efficiency via integrative (microenvironmental and genetic manipulation) and non-integrative (microenvironmental manipulation) induction protocols for delivering hDPSC-derived IPCs (hDPSC-IPCs). The results suggest distinct induction efficiency for both the induction approaches in terms of 3-dimensional colony structure, yield, pancreatic mRNA markers, and functional property upon multi-dosage glucose challenge. These findings will support the future establishment of a clinically applicable IPCs and pancreatic lineage production platform.

In vitro Induction of Human Dental Pulp Stem Cells Toward Pancreatic Lineages

This protocol presents a comparison between two different induction protocols for differentiating human dental pulp stem cells (hDPSCs) toward pancreatic lineages in vitro: the integrative protocol and the non-integrative protocol. The integrative protocol generates more insulin producing cells (IPCs).

As of 2000, the success of pancreatic islet transplantation using the Edmonton protocol to treat type I diabetes mellitus still faced some obstacles. ...

Bioengineering

De Novo Generation of Somatic Stem Cells by YAP/TAZ

Here we present protocols to isolate primary differentiated cells and turn them into stem/progenitor cells (SCs) of the same lineage by transient expression of the transcription factor YAP. With this method, luminal differentiated (LD) cells of the mouse mammary gland are converted into cells that exhibit molecular and functional properties of mammary SCs. YAP also turns fully differentiated pancreatic exocrine cells into pancreatic duct-like progenitors. Similarly, to endogenous, natural SCs, YAP-induced stem-like cells ("ySCs") can be eventually expanded as organoid cultures long term in vitro, without further need of ectopic YAP/TAZ, as ySCs are endowed with a heritable self-renewing SC-like state. 
The reprogramming procedure presented here offers the possibility to generate and expand in vitro progenitor cells of various tissue sources starting from differentiated cells. The straightforward expansion of somatic cells ex vivo has implications for regenerative medicine, for understanding mechanisms of tumor initiation and, more in general, for cell and developmental biology studies.

De Novo Generation of Somatic Stem Cells by YAP/TAZ

Availability of somatic SCs is crucial for regenerative medicine, disease modeling and to gain insight into SC properties. Here we present experimental strategies to reprogram, in vitro, differentiated adult cells into their corresponding expandable tissue-specific stem/progenitor cells by the transient expression of the single transcriptional co-activator YAP.

Reprogramming Pancreatic Ductal Adenocarcinoma to Pluripotency

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