Insulin regulates human pancreatic endocrine cell differentiation in vitro.

OBJECTIVE: The consequences of mutations in genes associated with monogenic forms of diabetes on human pancreas development cannot be studied in a time-resolved fashion in vivo. More specifically, if recessive mutations in the insulin gene influence human pancreatic endocrine lineage formation is still an unresolved question. METHODS: To model the extremely reduced insulin levels in patients with recessive insulin gene mutations, we generated a novel knock-in H2B-Cherry reporter human induced pluripotent stem cell (iPSC) line expressing no insulin upon differentiation to stem cell-derived (SC-) ß cells in vitro. Differentiation of iPSCs into the pancreatic and endocrine lineage, combined with immunostaining, Western blotting and proteomics analysis phenotypically characterized the insulin gene deficiency in SC-islets. Furthermore, we leveraged FACS analysis and confocal microscopy to explore the impact of insulin shortage on human endocrine cell induction, composition, differentiation and proliferation. RESULTS: Interestingly, insulin-deficient SC-islets exhibited low insulin receptor (IR) signaling when stimulated with glucose but displayed increased IR sensitivity upon treatment with exogenous insulin. Furthermore, insulin shortage did not alter neurogenin-3 (NGN3)-mediated endocrine lineage induction. Nevertheless, lack of insulin skewed the SC-islet cell composition with an increased number in SC-ß cell formation at the expense of SC-α cells. Finally, insulin deficiency reduced the rate of SC-ß cell proliferation but had no impact on the expansion of SC-α cells. CONCLUSIONS: Using iPSC disease modelling, we provide first evidence of insulin function in human pancreatic endocrine lineage formation. These findings help to better understand the phenotypic impact of recessive insulin gene mutations during pancreas development and shed light on insulin gene function beside its physiological role in blood glucose regulation.

The orphan MRGPRF receptor is expressed in entero-endocrine cells of the human gut mucosa.

In the past years, it has become clear that the family of Mas-related G protein-coupled receptors plays a central role in neuro-immune communication at mucosal barrier surfaces, in particular in the skin. Remarkably, MRGPR expression at other mucosal surfaces remains poorly characterized. To fill this gap in our understanding, the present study was undertaken to screen and verify the expression of the human MRGPR family members in the mucosal biopsies of the human gastrointestinal (GI) tract. Our findings revealed that, of all human MRGPRs family members, only MRGPRF mRNA is expressed at detectable levels in human mucosal biopsies of both terminal ileum and sigmoid colon. Furthermore, immunohistochemical stainings revealed that MRGPRF is specifically expressed by mucosal entero-endocrine cells (EECs). Overall, this study showed for the first time that the human ileum and colonic mucosa represent a novel expression site for the orphan MRGPRF, more specifically in EECs.

Single-cell transcriptome analysis of NEUROG3+ cells during pancreatic endocrine differentiation with small molecules.

The efficiency of inducing human embryonic stem cells into NEUROG3+ pancreatic endocrine cells is a bottleneck in stem cell therapy for diabetes. To understand the cell properties and fate decisions during differentiation, we analyzed the modified induction method using single-cell transcriptome and found that DAPT combined with four factors (4FS): nicotinamide, dexamethasone, forskolin and Alk5 inhibitor II (DAPT + 4FS) increased the expression of NEUROG3 to approximately 34.3%. The increased NEUROG3+ cells were mainly concentrated in Insulin + Glucagon + (INS + GCG+) and SLAC18A1 + Chromogranin A+(SLAC18A1 + CHGA +) populations, indicating that the increased NEUROG3+ cells promoted the differentiation of pancreatic endocrine cells and enterochromaffin-like cells. Single-cell transcriptome analysis provided valuable clues for further screening of pancreatic endocrine cells and differentiation of pancreatic islet cells. The gene set enrichment analysis (GSEA) suggest that we can try to promote the expression of INS + GCG+ population by up-regulating G protein-coupled receptor (GPCR) and mitogen-activated protein kinase signals and down-regulating Wnt, NIK/NF-KappaB and cytokine-mediated signal pathways. We can also try to regulate GPCR signaling through PLCE1, so as to increase the proportion of NEUROG3+ cells in INS+GCG+ populations. To exclude non-pancreatic endocrine cells, ALCAMhigh CD9low could be used as a marker for endocrine populations, and ALCAMhigh CD9lowCDH1low could remove the SLC18A1 + CHGA+ population.

Effects of different coating materials on the morphological characteristics of chicken adenohypophyseal folliculo-stellate cells in vitro.

Chicken adenohypophyseal cells were cultured in plates coated with different materials, and their morphologies were examined to confirm the characteristics of chicken folliculo-stellate (FS) cells in vitro. The adenohypophyseal cells were dispersed with a collagenase/trypsin mixture in media and seeded in plates coated in either poly L-lysine (PLL), collagen, or laminin. After 7 days of culture, the cells were fixed and immunocytochemistry was performed. 5-Bromo-2'-deoxyuridine incorporation test indicated that the proliferation activity of the culture cells was different based on the coating materials, and it was higher in the collagen-coated plate than two other coating materials. Fluorescence immunocytochemistry was also performed using mixed antibodies against growth hormone, prolactin, luteinizing hormone ß-subunit, basic cytokeratin (bCK), and S100B. The culture cells on the PLL- and laminin-coated surfaces were round or oval in shape, and bCK-immunopositive FS cells were morphologically indistinguishable from endocrine cells. In the collagen-coated plate, many endocrine cells were round or oval in shape, but FS cells displayed a larger and flattened morphology. S100B-immunoreactions were localized in the nuclei of bCK-immunopositive FS cells. These results suggest that culturing the chicken adenohypophyseal cells in the collagen-coated plate enables the distinction of FS cells from endocrine cells.

Oral berberine ameliorates high-fat diet-induced obesity by activating TAS2Rs in tuft and endocrine cells in the gut.

BACKGROUND AND AIMS: Although oral berberine, a natural compound extracted from the Chinese herbal medicine curcumin, has low bioavailability, it is still effective in suppressing obesity; however, the underlying mechanism is unclear. Berberine can bind to bitter-taste receptors (TAS2Rs) in intestinal endocrine secretin tumor (STC-1) cells to promote glucagon-like peptide-1 (GLP-1) secretion. Notably, TAS2Rs also exist in the tuft cells of the gut. Therefore, this study aimed to explore whether the beneficial effect of oral berberine on obesity is dependent on bitter-taste signaling in the tuft cells of the gut. METHODS AND RESULTS: Standard chow diet (SCD) or high-fat diet (HFD) was administered to C57BL/6 mice, with or without berberine (100 mg/kg, 200 mg/kg, p. o.). The PLCß2 inhibitor U73122 was used to verify whether the anti-obesity effect of berberine was dependent on the bitter-taste signaling pathway. In this study, we observed that the oral administration of berberine alleviated HFD-induced obesity in mice that U73122 partially inhibited. Both in vivo and ex vivo, berberine upregulated the release of GLP-1, promoted the proliferation of tuft cells and secretion of IL-25 in obesity via the TAS2R signaling pathway. CONCLUSIONS: Oral berberine ameliorated HFD-induced obesity through the TAS2R-IL-25 signaling pathway in tuft cells in the gut. SIGNIFICANCE: We identified and functionally characterized the TAS2Rs and Gα-gustducin/Gß1γ13 signaling pathway utilized by tuft cells in response to oral berberine in obese mice and proposed a new mechanism underlying the anti-obesity effect of berberine.

Expression of p11 and heteromeric TASK channels in mouse adrenal cortical cells and H295R cells.

TWIK-related acid-sensitive K+ (TASK) channels are thought to contribute to the resting membrane potential in adrenal cortical (AC) cells. However, the molecular identity of TASK channels in AC cells have not yet been elucidated. Thus, immunocytochemical and molecular biological approaches were employed to investigate the expression and intracellular distribution of TASK1 and TASK3 in mouse AC cells and H295R cells derived from human adrenocortical carcinoma. Immunocytochemical study revealed that immunoreactive materials were mainly located in the cytoplasm for TASK1 and at the cell periphery for TASK3 in mouse AC cells. A similar pattern of localization was observed when GFP-TASK1 and GFP-TASK3 were exogenously expressed in H295R cells. In addition, p11 that is known to suppress the endoplasmic reticulum exit of TASK1 was localized in the cytoplasm in mouse AC and H295R cells, but not in adrenal medullary cells. Proximity ligation assay (PLA) suggested formation of heteromeric TASK1-3 channels that were found predominantly in the cytoplasm and weakly at the cell periphery. A similar distribution was observed following exogenous expression of tandem TASK1-3 channels in H295R cells. When stimulated by angiotensin II, however, tandem TASK1-3 channels were present mainly in the cytoplasm in all H295R cells. In contrast to that in H295R cells, tandem channels were exclusively located at the cell periphery in all non-stimulated and exclusively in the cytoplasm in stimulated PC12 cells, respectively. From these results, we conclude that TASK1 proteins are present mainly in the cytoplasm and minimally at the cell periphery as a heteromeric channel with TASK3, whereas the majority of TASK3 is at the cell periphery as homomeric and heteromeric channels.

Increased Expression of Viral Sensor MDA5 in Pancreatic Islets and in Hormone-Negative Endocrine Cells in Recent Onset Type 1 Diabetic Donors.

The interaction between genetic and environmental factors determines the development of type 1 diabetes (T1D). Some viruses are capable of infecting and damaging pancreatic ß-cells, whose antiviral response could be modulated by specific viral RNA receptors and sensors such as melanoma differentiation associated gene 5 (MDA5), encoded by the IFIH1 gene. MDA5 has been shown to be involved in pro-inflammatory and immunoregulatory outcomes, thus determining the response of pancreatic islets to viral infections. Although the function of MDA5 has been previously well explored, a detailed immunohistochemical characterization of MDA5 in pancreatic tissues of nondiabetic and T1D donors is still missing. In the present study, we used multiplex immunofluorescence imaging analysis to characterize MDA5 expression and distribution in pancreatic tissues obtained from 22 organ donors (10 nondiabetic autoantibody-negative, 2 nondiabetic autoantibody-positive, 8 recent-onset, and 2 long-standing T1D). In nondiabetic control donors, MDA5 was expressed both in α- and ß-cells. The colocalization rate imaging analysis showed that MDA5 was preferentially expressed in α-cells. In T1D donors, we observed an increased colocalization rate of MDA5-glucagon with respect to MDA5-insulin in comparison to nondiabetic controls; such increase was more pronounced in recent-onset with respect to long-standing T1D donors. Of note, an increased colocalization rate of MDA5-glucagon was found in insulin-deficient-islets (IDIs) with respect to insulin-containing-islets (ICIs). Strikingly, we detected the presence of MDA5-positive/hormone-negative endocrine islet-like clusters in T1D donors, presumably due to dedifferentiation or neogenesis phenomena. These clusters were identified exclusively in donors with recent disease onset and not in autoantibody-positive nondiabetic donors or donors with long-standing T1D. In conclusion, we showed that MDA5 is preferentially expressed in α-cells, and its expression is increased in recent-onset T1D donors. Finally, we observed that MDA5 may also characterize the phenotype of dedifferentiated or newly forming islet cells, thus opening to novel roles for MDA5 in pancreatic endocrine cells.

Interleukin-6 is dispensable in pituitary normal development and homeostasis but needed for pituitary stem cell activation following local injury.

Recently, we discovered that the cytokine interleukin-6 (IL-6) acts as a pituitary stem cell-activating factor, both when administered in vivo and when added to stem cell organoid cultures in vitro. Moreover, its expression, predominantly localized in the gland's stem and mesenchymal cells, promptly increases following damage in the adult pituitary, leading to stem-cell proliferative activation. Given these findings that IL-6 is involved in pituitary stem cell regulation, we addressed the question whether the cytokine has an impact on the pituitary phenotype during active phases of the gland's remodeling, in particular embryonic development and neonatal maturation, as well as during homeostasis at adulthood and aging, all unknown today. Using the IL-6 knock-out (KO) mouse model, we show that IL-6 is dispensable for pituitary embryonic and neonatal endocrine cell development, as well as for hormonal cell homeostasis in adult and aging glands. The findings match the absence of effects on the stem cell compartment at these stages. However, using this IL-6 KO model, we found that IL-6 is needed for the acute stem-cell proliferative activation reaction upon pituitary injury. Intriguingly, regeneration still occurs which may be due to compensatory behavior by other cytokines which are upregulated in the damaged IL-6 KO pituitary, although at lower but prolonged levels, which might lead to a delayed (and less forceful) stem cell response. Taken together, our study revealed that IL-6 is dispensable for normal pituitary development and homeostasis but plays a key role in the prompt stem cell activation upon local damage, although its presence is not essentially needed for the final regenerative realization.

Gene Signatures of NEUROGENIN3+ Endocrine Progenitor Cells in the Human Pancreas.

NEUROGENIN3+ (NEUROG3+) cells are considered to be pancreatic endocrine progenitors. Our current knowledge on the molecular program of NEUROG3+ cells in humans is largely extrapolated from studies in mice. We hypothesized that single-cell RNA-seq enables in-depth exploration of the rare NEUROG3+ cells directly in humans. We aligned four large single-cell RNA-seq datasets from postnatal human pancreas. Our integrated analysis revealed 10 NEUROG3+ epithelial cells from a total of 11,174 pancreatic cells. Noticeably, human NEUROG3+ cells clustered with mature pancreatic cells and epsilon cells displayed the highest frequency of NEUROG3 positivity. We confirmed the co-expression of NEUROG3 with endocrine markers and the high percentage of NEUROG3+ cells among epsilon cells at the protein level based on immunostaining on pancreatic tissue sections. We further identified unique genetic signatures of the NEUROG3+ cells. Regulatory network inference revealed novel transcription factors including Prospero homeobox protein 1 (PROX1) may act jointly with NEUROG3. As NEUROG3 plays a central role in endocrine differentiation, knowledge gained from our study will accelerate the development of beta cell regeneration therapies to treat diabetes.

Insm1, Neurod1, and Pax6 promote murine pancreatic endocrine cell development through overlapping yet distinct RNA transcription and splicing programs.

Insm1, Neurod1, and Pax6 are essential for the formation and function of pancreatic endocrine cells. Here, we report comparative immunohistochemical, transcriptomic, functional enrichment, and RNA splicing analyses of these genes using gene knock-out mice. Quantitative immunohistochemical analysis confirmed that elimination of each of these three factors variably impairs the proliferation, survival, and differentiation of endocrine cells. Transcriptomic analysis revealed that each factor contributes uniquely to the transcriptome although their effects were overlapping. Functional enrichment analysis revealed that genes downregulated by the elimination of Insm1, Neurod1, and Pax6 are commonly involved in mRNA metabolism, chromatin organization, secretion, and cell cycle regulation, and upregulated genes are associated with protein degradation, autophagy, and apoptotic process. Elimination of Insm1, Neurod1, and Pax6 impaired expression of many RNA-binding proteins thereby altering RNA splicing events, including for Syt14 and Snap25, two genes required for insulin secretion. All three factors are necessary for normal splicing of Syt14, and both Insm1 and Pax6 are necessary for the processing of Snap25. Collectively, these data provide new insights into how Insm1, Neurod1, and Pax6 contribute to the formation of functional pancreatic endocrine cells.

Review: Vaspin (SERPINA12) Expression and Function in Endocrine Cells.

Proper functioning of the body depends on hormonal homeostasis. White adipose tissue is now known as an endocrine organ due to the secretion of multiple molecules called adipokines. These proteins exert direct effects on whole body functions, including lipid metabolism, angiogenesis, inflammation, and reproduction, whereas changes in their level are linked with pathological events, such as infertility, diabetes, and increased food intake. Vaspin-visceral adipose tissue-derived serine protease inhibitor, or SERPINA12 according to serpin nomenclature, is an adipokine discovered in 2005 that is connected to the development of insulin resistance, obesity, and inflammation. A significantly higher amount of vaspin was observed in obese patients. The objective of this review was to summarize the latest findings about vaspin expression and action in endocrine tissues, such as the hypothalamus, pituitary gland, adipose tissue, thyroid, ovary, placenta, and testis, as well as discuss the link between vaspin and pathologies connected with hormonal imbalance.

The role of endocrine hormones in the pathogenesis of adolescent idiopathic scoliosis.

Adolescent idiopathic scoliosis (AIS) is a common spinal deformity characterized by changes in the three-dimensional structure of the spine. It usually initiates during puberty, the peak period of human growth when the secretion of numerous hormones is changing, and it is more common in females than in males. Accumulating evidence shows that the abnormal levels of many hormones including estrogen, melatonin, growth hormone, leptin, adiponectin and ghrelin, may be related to the occurrence and development of AIS. The purpose of this review is to provide a summary and critique of the research published on each hormone over the past 20 years, and to highlight areas for future study. It is hoped that the presentation will help provide a better understanding of the role of endocrine hormones in the pathogenesis of AIS.

Architecture of the Pancreatic Islets and Endocrine Cell Arrangement in the Embryonic Pancreas of the Grass Snake (Natrix natrix L.). Immunocytochemical Studies and 3D Reconstructions.

During the early developmental stages of grass snakes, within the differentiating pancreas, cords of endocrine cells are formed. They differentiate into agglomerates of large islets flanked throughout subsequent developmental stages by small groups of endocrine cells forming islets. The islets are located within the cephalic part of the dorsal pancreas. At the end of the embryonic period, the pancreatic islet agglomerates branch off, and as a result of their remodeling, surround the splenic "bulb". The stage of pancreatic endocrine ring formation is the first step in formation of intrasplenic islets characteristics for the adult specimens of the grass snake. The arrangement of endocrine cells within islets changes during pancreas differentiation. Initially, the core of islets formed from B and D cells is surrounded by a cluster of A cells. Subsequently, A, B, and D endocrine cells are mixed throughout the islets. Before grass snake hatching, A and B endocrine cells are intermingled within the islets, but D cells are arranged centrally. Moreover, the pancreatic polypeptide (PP) cells are not found within the embryonic pancreas of the grass snake. Variation in the proportions of different cell types, depending on the part of the pancreas, may affect the islet function-a higher proportion of glucagon cells is beneficial for insulin secretion.

HNRNPA2B1 regulates tamoxifen- and fulvestrant-sensitivity and hallmarks of endocrine resistance in breast cancer cells.

Despite new combination therapies improving survival of breast cancer patients with estrogen receptor α (ER+) tumors, the molecular mechanisms for endocrine-resistant disease remain unresolved. Previously we demonstrated that expression of the RNA binding protein and N6-methyladenosine (m6A) reader HNRNPA2B1 (A2B1) is higher in LCC9 and LY2 tamoxifen (TAM)-resistant ERα breast cancer cells relative to parental TAM-sensitive MCF-7 cells. Here we report that A2B1 protein expression is higher in breast tumors than paired normal breast tissue. Modest stable overexpression of A2B1 in MCF-7 cells (MCF-7-A2B1 cells) resulted in TAM- and fulvestrant- resistance whereas knockdown of A2B1 in LCC9 and LY2 cells restored TAM and fulvestrant, endocrine-sensitivity. MCF-7-A2B1 cells gained hallmarks of TAM-resistant metastatic behavior: increased migration and invasion, clonogenicity, and soft agar colony size, which were attenuated by A2B1 knockdown in MCF-7-A2B1 and the TAM-resistant LCC9 and LY2 cells. MCF-7-A2B1, LCC9, and LY2 cells have a higher proportion of CD44+/CD24-/low cancer stem cells (CSC) compared to MCF-7 cells. MCF-7-A2B1 cells have increased ERα and reduced miR-222-3p that targets ERα. Like LCC9 cells, MCF-7-A2B1 have activated AKT and MAPK that depend on A2B1 expression and are growth inhibited by inhibitors of these pathways. These data support that targeting A2B1 could provide a complimentary therapeutic approach to reduce acquired endocrine resistance.

Patient-derived scaffolds as a drug-testing platform for endocrine therapies in breast cancer.

Three-dimensional cell culture platforms based on decellularised patient-based microenvironments provide in vivo-like growth conditions allowing cancer cells to interact with intact structures and components of the surrounding tissue. A patient-derived scaffold (PDS) model was therefore evaluated as a testing platform for the endocrine therapies (Z)-4-Hydroxytamoxifen (4OHT) and fulvestrant as well as the CDK4/6-inhibitor palbociclib, monitoring the treatment responses in breast cancer cell lines MCF7 and T47D adapted to the patient-based microenvironments. MCF7 cells growing in PDSs showed increased resistance to 4OHT and fulvestrant treatment (100- and 20-fold) compared to 2D cultures. Quantitative PCR analyses of endocrine treated cancer cells in PDSs revealed upregulation of pluripotency markers further supported by increased self-renewal capacity in sphere formation assays. When comparing different 3D growth platforms including PDS, matrigel, gelatin sponges and 3D-printed hydrogels, 3D based cultures showed slightly varying responses to fulvestrant and palbociclib whereas PDS and matrigel cultures showed more similar gene expression profiles for 4OHT treatment compared to the other platforms. The results support that the PDS technique maximized to provide a multitude of smaller functional PDS replicates from each primary breast cancer, is an up-scalable patient-derived drug-testing platform available for gene expression profiling and downstream functional assays.

CD9-positive cells in the intermediate lobe migrate into the anterior lobe to supply endocrine cells.

The adenohypophysis is composed of the anterior and intermediate lobes (AL and IL), and secretes important hormones for growth, sexual development, metabolism, and reproduction. In the marginal cell layer (MCL) facing Rathke's cleft between the IL and AL, cluster of differentiation (CD) 9-, CD81-, S100ß-, and SOX2-quadruple positive (CD9/CD81/S100ß/SOX2-positive) cells in the adult IL are settled as tissue-resident stem/progenitor cells supplying hormone-producing cells to the AL. However, it is unclear how CD9/CD81/S100ß/SOX2-positive cells in the IL-side MCL migrate into the AL across Rathke's cleft. In the present study, we performed chimeric pituitary tissue culture using S100ß/GFP-transgenic rats and Wistar rats, and traced the footprint of S100ß/GFP-expressing cells. We detected IL-side S100ß/GFP-expressing cells in the AL tissue, demonstrating that these cells migrate from the IL to the AL. However, the cells failed to migrate in the opposite direction. Consistently, scanning electron microscopic analysis revealed well-developed cytoplasmic protrusions in the IL-side MCL, but not in the AL-side MCL, suggesting that IL-side CD9/CD81/S100ß/SOX2-positive cells had higher migratory activity. We also searched for a specific marker for IL-side CD9/CD81/S100ß/SOX2-positive cells and identified tetraspanin 1 (TSPAN1) from microarray analysis. Downregulation of Tspan1 by specific siRNA impaired cell migration and significantly reduced expression of snail family transcriptional repressor 2 (Slug), a marker of epithelial-mesenchymal transition (EMT). Therefore, CD9/CD81/S100ß/SOX2-positive cells in the IL-side MCL can be stem/progenitor cells that provide stem/progenitor cells to the AL-side MCL via SLUG-mediated EMT and cell migration.

Renin Cell Baroreceptor, a Nuclear Mechanotransducer Central for Homeostasis.

[Figure: see text].

Human Pluripotent Stem Cells to Model Islet Defects in Diabetes.

Diabetes mellitus is characterized by elevated levels of blood glucose and is ultimately caused by insufficient insulin production from pancreatic beta cells. Different research models have been utilized to unravel the molecular mechanisms leading to the onset of diabetes. The generation of pancreatic endocrine cells from human pluripotent stem cells constitutes an approach to study genetic defects leading to impaired beta cell development and function. Here, we review the recent progress in generating and characterizing functional stem cell-derived beta cells. We summarize the diabetes disease modeling possibilities that stem cells offer and the challenges that lie ahead to further improve these models.

SOX2 is required independently in both stem and differentiated cells for pituitary tumorigenesis in p27-null mice.

P27, a cell cycle inhibitor, is also able to drive repression of Sox2 This interaction plays a crucial role during development of p27-/- pituitary tumors because loss of one copy of Sox2 impairs tumorigenesis [H. Li et al., Cell Stem Cell 11, 845-852 (2012)]. However, SOX2 is expressed in both endocrine and stem cells (SCs), and its contribution to tumorigenesis in either cell type is unknown. We have thus explored the cellular origin and mechanisms underlying endocrine tumorigenesis in p27-/- pituitaries. We found that pituitary hyperplasia is associated with reduced cellular differentiation, in parallel with increased levels of SOX2 in stem and endocrine cells. Using conditional loss-of-function and lineage tracing approaches, we show that SOX2 is required cell autonomously in p27-/- endocrine cells for these to give rise to tumors, and in SCs for promotion of tumorigenesis. This is supported by studies deleting the Sox2 regulatory region 2 (Srr2), the target of P27 repressive action. Single cell transcriptomic analysis further reveals that activation of a SOX2-dependent MAPK pathway in SCs is important for tumorigenesis. Altogether, our data highlight different aspects of the role of SOX2 following loss of p27, according to cellular context, and uncover an unexpected SOX2-dependent tumor-promoting role for SCs. Our results imply that targeting SCs, in addition to tumor cells, may represent an efficient antitumoral strategy in certain contexts.