Transcription Factors Oct4 Research Articles

TGFβ1 induces CXCL1 to promote stemness features in lung cancer.

Chemokines critically orchestrate the tumorigenesis, metastasis, and stemness features of cancer cells that lead to poor outcomes. High plasma levels of transforming growth factor-β1 (TGFβ1) correlate with poor prognostic features in advanced lung cancer patients, thus suggesting the importance of TGFβ1 in the lung tumor microenvironment. However, the role of chemokines in TGFβ1-induced tumor stemness features remains unclear. Here, we clarify the previously undocumented role of CXCL1 in TGFβ1-induced lung cancer stemness features. CXCL1 and its receptor CXCR2 were significantly upregulated in TGFβ1-induced lung cancer stem cells (CSCs). CXCL1 silencing (shCXCL1) suppressed stemness gene expression, tumorsphere formation, colony formation, drug resistance, and in vivo tumorigenicity in TGFβ1-induced lung tumorspheres. Immunohistochemistry staining showed that patients with stage II/III lung cancer had higher expression levels of CXCL1. The levels of CXCL1 were positively associated with lymph node metastasis and correlated with the expression of the CSC transcription factor Oct-4. Furthermore, online database analysis revealed that CXCL1 expression was negatively correlated with lung cancer survival in patients. Patients with high TGFβ1/CXCL1/CD44 co-expression had a worse survival rate. We suggest that CXCL1 serves as a crucial factor in TGFβ1-induced stemness features of lung cancer.

Generation of two induced pluripotent stem cell lines from two sporadic amyotrophic lateral sclerosis patients

Peripheral blood mononuclear cells were obtained from two patients diagnosed with amyotrophic lateral sclerosis (ALS), a 47-year-old female and a 45-year-old male. Induced pluripotent stem cells (iPSCs) were generated using a non-integrating SeV-based method, delivering the transcription factors OCT4, SOX2, c-MYC, and KLF4. These transgene-free iPSC lines exhibited typical pluripotent cell morphology, expressed pluripotency-associated markers, and had tri-lineage differentiation potential. Both iPSC lines were free of mycoplasma contamination and displayed normal karyotypes. The availability of these two cell lines provides a promising opportunity to use sporadic ALS models for investigating the intricate pathological mechanisms of ALS.

Sustained Vision Recovery by OSK Gene Therapy in a Mouse Model of Glaucoma.

Glaucoma, a chronic neurodegenerative disease, is a leading cause of age-related blindness worldwide and characterized by the progressive loss of retinal ganglion cells (RGCs) and their axons. Previously, we developed a novel epigenetic rejuvenation therapy, based on the expression of the three transcription factors Oct4, Sox2, and Klf4 (OSK), which safely rejuvenates RGCs without altering cell identity in glaucomatous and old mice after 1 month of treatment. In the current year-long study, mice with continuous or cyclic OSK expression induced after glaucoma-induced vision damage had occurred were tracked for efficacy, duration, and safety. Surprisingly, only 2 months of OSK fully restored impaired vision, with a restoration of vision for 11 months with prolonged expression. In RGCs, transcription from the doxycycline (DOX)-inducible Tet-On AAV system, returned to baseline 4 weeks after DOX withdrawal. Significant vision improvements remained for 1 month post switching off OSK, after which the vision benefit gradually diminished but remained better than baseline. Notably, no adverse effects on retinal structure or body weight were observed in glaucomatous mice with OSK continuously expressed for 21 months providing compelling evidence of efficacy and safety. This work highlights the tremendous therapeutic potential of rejuvenating gene therapies using OSK, not only for glaucoma but also for other ocular and systemic injuries and age-related diseases.

In vivo reprogramming leads to premature death linked to hepatic and intestinal failure.

The induction of cellular reprogramming via expression of the transcription factors Oct4, Sox2, Klf4 and c-Myc (OSKM) can drive dedifferentiation of somatic cells and ameliorate age-associated phenotypes in multiple tissues and organs. However, the benefits of long-term in vivo reprogramming are limited by detrimental side-effects. Here, using complementary genetic approaches, we demonstrated that continuous induction of the reprogramming factors in vivo leads to hepatic and intestinal dysfunction resulting in decreased body weight and contributing to premature death (within 1 week). By generating a transgenic reprogrammable mouse strain, avoiding OSKM expression in both liver and intestine, we reduced the early lethality and adverse effects associated with in vivo reprogramming and induced a decrease in organismal biological age. This reprogramming mouse strain, which allows longer-term continuous induction of OSKM with attenuated toxicity, can help better understand rejuvenation, regeneration and toxicity during in vivo reprogramming.

AKT1 induces Nanog promoter in a SUMOylation-dependent manner in different pluripotent contexts

AKT/PKB is a kinase crucial for pluripotency maintenance in pluripotent stem cells. Multiple post-translational modifications modulate its activity. We have previously demonstrated that AKT1 induces the expression of the pluripotency transcription factor Nanog in a SUMOylation-dependent manner in mouse embryonic stem cells. Here, we studied different cellular contexts and main candidates that could mediate this induction. Our results strongly suggest the pluripotency transcription factors OCT4 and SOX2 are not essential mediators. Additionally, we concluded that this induction takes place in different pluripotent contexts but not in terminally differentiated cells. Finally, the cross-matching analysis of ESCs, iPSCs and MEFs transcriptomes and AKT1 phosphorylation targets provided new clues about possible factors that could be involved in the SUMOylation-dependent Nanog induction by AKT.

KPT6566 induces apoptotic cell death and suppresses the tumorigenicity of testicular germ cell tumors.

Testicular germ cell tumors (TGCTs) frequently affect adolescent and young adult males. Although TGCT is more responsive to cisplatin-based chemotherapy than other solid tumors, some patients are nonresponders, and following treatment, many patients continue to experience acute and long-term cytotoxic effects from cisplatin-based chemotherapy. Consequently, it is imperative to develop new therapeutic modalities for treatment-resistant TGCTs. Peptidyl-prolyl isomerase (Pin1) regulates the activity and stability of many cancer-associated target proteins. Prior findings suggest that Pin1 contributes to the pathogenesis of multiple human cancers. However, the specific function of Pin1 in TGCTs has not yet been elucidated. TGCT cell proliferation and viability were examined using cell cycle analysis and apoptosis assays following treatment with KPT6566, a potent, selective Pin1 inhibitor that covalently binds to the catalytic domain of Pin1. A xenograft mouse model was used to assess the effect of KPT6566 on tumor growth in vivo. KPT6566 effectively suppressed cell proliferation, colony formation, and ATP production in P19 and NCCIT cells. Further, KPT6566 induced apoptotic cell death by generating cellular reactive oxygen species and downregulating the embryonic transcription factors Oct-4 and Sox2. Finally, KPT6566 treatment significantly reduced tumor volume and mass in P19 cell xenografts. The Pin1 inhibitor KPT6566 has significant antiproliferative and antitumor effects in TGCT cells. These findings suggest that Pin1 inhibitors could be considered as a potential therapeutic approach for TGCTs.

Selective Inhibition of mTORC1 Signaling Supports the Development and Maintenance of Pluripotency.

Insight into the molecular mechanisms governing the development and maintenance of pluripotency is important for understanding early development and the use of stem cells in regenerative medicine. We demonstrate the selective inhibition of mTORC1 signaling is important for developing the inner cell mass (ICM) and the self-renewal of human embryonic stem cells. S6K suppressed the expression and function of pluripotency-related transcription factors (PTFs) OCT4, SOX2, and KLF4 through phosphorylation and ubiquitin proteasome-mediated protein degradation, indicating that S6K inhibition is required for pluripotency. PTFs inhibited mTOR signaling. The phosphorylation of S6 was decreased in PTF-positive cells of the ICM in embryos. Activation of mTORC1 signaling blocked ICM formation and the selective inhibition of S6K by rapamycin increased the ICM size in mouse blastocysts. Thus, selective inhibition of mTORC1 signaling supports the development and maintenance of pluripotency.

Regulatory Elements Outside Established Pou5f1 Gene Boundaries Are Required for Multilineage Differentiation of Embryonic Stem Cells.

The transcription factor Oct4 can rightfully be considered a pivotal element in maintaining pluripotency. In addition, its ability to function as a pioneer factor enables the reprogramming of somatic cells back into a pluripotent state. To better understand the regulation of the Oct4-encoding gene (Pou5f1), the main genetic elements that regulate its expression in different states of pluripotency ought to be identified. While some elements have been well characterized for their ability to drive Pou5f1 expression, others have yet to be determined. In this work, we show that translocation of the Pou5f1 gene fragment purported to span all essential cis-elements, including the well-known distal and proximal enhancers (DE and PE), into the Rosa26 locus impairs the self-renewal of mouse embryonic stem cells (ESCs) in the naïve pluripotency state, as well as their further advancement through the formative and primed pluripotency states, inducing overall differentiation failure. These results suggest that regulatory elements located outside the previously determined Pou5f1 boundaries are critical for the proper spatiotemporal regulation of this gene during development, indicating the need for their better characterization.

Abstract 123: Partial Endothelial Cell In Vivo Reprogramming Reverses The Hypercontractility To Phenylephrine In Resistance Arteries Isolated From Males But Not From Females BPH/2J Hypertensive Mice

The Schlager hypertensive (BPH/2J) mouse strain is a genetic model of spontaneoushypertension. Endothelial dysfunction is a hallmark characteristic of hypertension,including endothelial phenotypic transition. We hypothesized that treating endothelialcells with the transcription factors Oct4, Sox2 and Klf4, will lead to partial reprogramming,reduce non-functional phenotype changes, and prevent vascular dysfunction. Mouseendothelial cells were transduced with a lentiviral vector containing VE-cadherin-Oct4-Sox2-Klf4-eGFP (LVTF), control lentivirus (LVCO), or phosphate buffer saline (PBS).After 72h, cell migration and proliferation, Ki67 marker, and the endothelial progenitormarkers (CD31, CD133 and CD34) were evaluated. Male or female BPH/2J mice (33-42-week-old) and their age-matched controls BPN/3J (normotensive) received a singleinjection of LVCO or LVTF (100μL) via the tail vein and were evaluated after 10 days.Systolic blood pressure (SBP) was measured directly by catheterization of the left carotidartery. Mesenteric resistance arteries were isolated and mounted on wire myographs toevaluate phenylephrine-induced contraction. Data were analyzed using One-way orTwo-way ANOVA, with Bonferroni correction ( p <0.05). Lentivirus-transduced endothelialcells had eGFP fluorescence (LVCO: 45±2%, LVTF:19±1%, n=5), and LVTF increasedOct4 (LVTF: 5.6±0.7% vs. LVCO: 1.8±0.2% vs. PBS: 1.5±0.4%, n=5) and CD133 (LVTF:11.7±0.8% vs. LVCO: 7.6±0.3% vs. PBS: 6.5±0.5%, n=5), but not CD31, CD34 or Ki67.Cell migration was lower in LVTF (71±2%) than LVCO cells (90±2%, n=5). Male andfemale BPH/2J treated with LVCO had higher SBP (male: 103±3mmHg, female:95±4mmHg, n=2-3) compared to BPN/3J mice (male: 88±1mmHg, female: 80±4mmHg,n=2-6), and LVTF treatment tended to decrease SBP in male BPH/2J (86±2mmHg, n=2, p =0.0548) but not in female mice (90±4mmHg, n=3). Phenylephrine-induced contractionwas reduced in arteries from male BPH/2J treated with LVTF (6.77±0.90mN, n=3), butnot in female mice (11.01±1.45mN, n=3) compared to LVCO (male: 12.23±0.15mN;female: 10.77±0.92mN; n=2-3). These data reveal that partial endothelial cellreprogramming in vivo is a new strategy to prevent endothelial dysfunction in malehypertensive mice.1

Application of the Yamanaka Transcription Factors Oct4, Sox2, Klf4, and c-Myc from the Laboratory to the Clinic.

The transcription factors Oct4, Sox2, Klf4, and c-Myc enable the reprogramming of somatic cells into induced pluripotent cells. Reprogramming generates newly differentiated cells for potential therapies in cancer, neurodegenerative diseases, and rejuvenation processes. In cancer therapies, these transcription factors lead to a reduction in the size and aggressiveness of certain tumors, such as sarcomas, and in neurodegenerative diseases, they enable the production of dopaminergic cells in Parkinson's disease, the replacement of affected neuronal cells in olivopontocerebellar atrophy, and the regeneration of the optic nerve. However, there are limitations, such as an increased risk of cancer development when using Klf4 and c-Myc and the occurrence of abnormal dyskinesias in the medium term, possibly generated by the uncontrolled growth of differentiated dopaminergic cells and the impairment of the survival of the new cells. Therefore, the Yamanaka transcription factors have shown therapeutic potential through cell reprogramming for some carcinomas, neurodegenerative diseases, and rejuvenation. However, the limitations found in the studies require further investigation before the use of these transcription factors in humans.

Drug Discovery and Development of miRNA-Based Nucleotide Drugs for Gastrointestinal Cancer.

Short non-coding RNAs, miRNAs, play roles in the control of cell growth and differentiation in cancer. Reportedly, the introduction of miRNAs could reduce the biologically malignant behavior of cancer cells, suggesting a possible use as therapeutic reagents. Given that the forced expression of several miRNAs, including miR-302, results in the cellular reprograming of human and mouse cells, which is similar to the effects of the transcription factors Oct4, Sox2, Klf4, and c-Myc, this suggests that the selective introduction of several miRNAs will be able to achieve anti-cancer effects at the epigenetic and metabolic levels. In this review article, we bring together the recent advances made in studies of microRNA-based therapeutic approaches to therapy-resistant cancers, especially in gastrointestinal organs.

Multiple lineage-specific epigenetic landscapes at the antigen receptor loci.

Antigen receptors (AgRs) expressed on B and T cells provide the adaptive immune system with ability to detect numerous foreign antigens. Epigenetic features of B cell receptor (BCR) and T cell receptor (TCR) genes were previously studied in lymphocytes, but little is known about their epigenetic features in other cells. Here, we explored histone modifications and transcription markers at the BCR and TCR loci in lymphocytes (pro-B, DP T cells, and mature CD4+ T cells), compared to embryonic stem (ES) cells and neurons. In B cells, the BCR loci exhibited active histone modifications and transcriptional markers indicative of active loci. Similar results were observed at the TCR loci in T cells. All loci were largely inactive in neurons. Surprisingly, in ES cells all AgR loci displayed a high degree of active histone modifications and markers of active transcription. Locations of these active histone modifications in ES cells were largely distinct from those in pro-B cells, and co-localized at numerous binding locations for transcription factors Oct4, Sox2, and Nanog. ES and pro-B cells also showed distinct binding patterns for the ubiquitous transcription factor YY1 and chromatin remodeler Brg1. On the contrary, there were many overlapping CCCTC-binding factor (CTCF) binding patterns when comparing ES cells, pro-B cells, and neurons. Our study identifies epigenetic features in ES cells and lymphocytes that may be related to ES cell pluripotency and lymphocyte tissue-specific activation at the AgR loci.

Ang II Promotes ET-1 Production by Regulating NOX2 Activity Through Transcription Factor Oct-1.

Increasing evidence suggests that superoxide ions produced by NOX (nicotinamide adenine dinucleotide phosphate oxidases) mediate vascular effects of Ang II (angiotensin II) evoked by atherogenic diets. Here, we analyzed the mechanism by which NOX2 contributes to Ang II-induced ET-1 (endothelin 1) production in human microvascular endothelial cells. The effects of high-fat diet were compared between WT (wild type) and Nox2 (mouse NOX2 gene)-deficient mice. ET-1 production and NOX2 expression by human microvascular endothelial cells in vitro were analyzed by ELISA, reverse transcription quantitative polymerase chain reaction, electrophoretic mobility shift assay, promoter deletions, RNA interference, and pharmacological inhibition. Production of superoxide anions was visualized by fluorescent cell labeling. Feeding mice high-fat diet for 10 weeks increased cardiac expression and plasma levels of Ang II and ET-1 in WT but not in Nox2-deficient animals. Exposure of human microvascular endothelial cells to Ang II resulted in increased ET-1 production, which could be blocked by silencing NOX2 (human NOX2 gene). Ang II promoted NOX2 expression through induction of the Oct-1 (human/mouse octamer binding transcription factor 1 protein) and activation of the NOX2 promoter region containing Oct-1-binding sites. Stimulation of NOX2 expression by Ang II was associated with increased production of superoxide anions. Inhibition of Oct-1 by small interfering RNA reduced Ang II-induced NOX2 expression and superoxide anion production, and neutralization of superoxide by SOD (superoxide dismutase) abolished Ang II-stimulated ET1 (human ET-1 gene) promoter activity, ET1 mRNA expression, and ET-1 release. Ang II may promote ET-1 production in the endothelium in response to atherogenic diets through a mechanism that involves the transcription factor Oct-1 and the increased formation of superoxide anions by NOX2.

HSV-1 selectively packs the transcription factor Oct-1 into EVs to facilitate its infection.

HSV-1 hijacks the cellular vesicular secretion system and promotes the secretion of extracellular vesicles (EVs) from infected cells. This is believed to facilitate the maturation, secretion, intracellular transportation and immune evasion of the virus. Intriguingly, previous studies have shown that noninfectious EVs from HSV-1-infected cells exert antiviral effects on HSV-1 and have identified host restrictive factors, such as STING, CD63, and Sp100 packed in these lipid bilayer-enclosed vesicles. Octamer-binding transcription factor-1 (Oct-1) is shown here to be a pro-viral cargo in non-virion-containing EVs during HSV-1 infection and serves to facilitate virus dissemination. Specifically, during HSV-1 infection, the nuclear localized transcription factor Oct-1 displayed punctate cytosolic staining that frequently colocalized with VP16 and was increasingly secreted into the extracellular space. HSV-1 grown in cells bereft of Oct-1 (Oct-1 KO) was significantly less efficient at transcribing viral genes during the next round of infection. In fact, HSV-1 promoted increased exportation of Oct-1 in non-virion-containing EVs, but not the other VP16-induced complex (VIC) component HCF-1, and EV-associated Oct-1 was promptly imported into the nucleus of recipient cells to facilitate the next round of HSV-1 infection. Interestingly, we also found that EVs from HSV-1-infected cells primed cells for infection by another RNA virus, vesicular stomatitis virus. In summary, this investigation reports one of the first pro-viral host proteins packed into EVs during HSV-1 infection and underlines the heterogenetic nature and complexity of these noninfectious double-lipid particles.

IMMUNOEXPRESSION OF STEM CELL MARKERS IN AMELOBLASTOMA

Objective Ameloblastoma (AME) is a benign, odontogenic neoplasm characterized by a locally invasive growth pattern. In the interest of understanding the aggressiveness of neoplasms, research on the role of stem cells has gained prominence. SOX-2, NANOG, and OCT4 transcription factors are important stem cell biomarkers. Study Design Immunohistochemistry was performed to verify the expression of these transcription factors in tissue samples of AME, dentigerous cyst (CD), and dental follicle (DF). In addition, indirect immunofluorescence and transcriptomic analysis were performed from a cell line derived from AME (AME-hTERT). Results The expression of SOX-2, NANOG, and OCT4 was observed in tissue samples and in the AME-hTERT cell line. Higher immunostaining of the studied proteins was observed in AME in comparison to CD and FD (p<0.001). There was also an association of OCT4 and SOX-2 proteins in AME neoplastic cells (p=0.0294). Transcriptomic analysis revealed a network of mutual interaction between the three transcription factors. Conclusion The presence of these biomarkers indicates a probable role of stem cells in the genesis and progression of AME. Ameloblastoma (AME) is a benign, odontogenic neoplasm characterized by a locally invasive growth pattern. In the interest of understanding the aggressiveness of neoplasms, research on the role of stem cells has gained prominence. SOX-2, NANOG, and OCT4 transcription factors are important stem cell biomarkers. Immunohistochemistry was performed to verify the expression of these transcription factors in tissue samples of AME, dentigerous cyst (CD), and dental follicle (DF). In addition, indirect immunofluorescence and transcriptomic analysis were performed from a cell line derived from AME (AME-hTERT). The expression of SOX-2, NANOG, and OCT4 was observed in tissue samples and in the AME-hTERT cell line. Higher immunostaining of the studied proteins was observed in AME in comparison to CD and FD (p<0.001). There was also an association of OCT4 and SOX-2 proteins in AME neoplastic cells (p=0.0294). Transcriptomic analysis revealed a network of mutual interaction between the three transcription factors. The presence of these biomarkers indicates a probable role of stem cells in the genesis and progression of AME.

A microphysiological model of bone development and regeneration

Endochondral ossification (EO) is an essential biological process than underpins how human bones develop, grow, and heal in the event of a fracture. So much is unknown about this process, thus clinical manifestations of dysregulated EO cannot be adequately treated. This can be partially attributed to the absence of predictive in vitro models of musculoskeletal tissue development and healing, which are integral to the development and preclinical evaluation of novel therapeutics. Microphysiological systems, or organ-on-chip devices, are advanced in vitro models designed for improved biological relevance compared to traditional in vitro culture models. Here we develop a microphysiological model of vascular invasion into developing/regenerating bone, thereby mimicking the process of EO. This is achieved by integrating endothelial cells and organoids mimicking different stages of endochondral bone development within a microfluidic chip. This microphysiological model is able to recreate key events in EO, such as the changing angiogenic profile of a maturing cartilage analogue, and vascular induced expression of the pluripotent transcription factors SOX2 and OCT4 in the cartilage analogue. This system represents an advanced in vitro platform to further EO research, and may also serve as a modular unit to monitor drug responses on such processes as part of a multi-organ system.

Histone modifications regulate pioneer transcription factor cooperativity

Pioneer transcription factors have the ability to access DNA in compacted chromatin1. Multiple transcription factors can bind together to a regulatory element in a cooperative way, and cooperation between the pioneer transcription factors OCT4 (also known as POU5F1) and SOX2 is important for pluripotency and reprogramming2–4. However, the molecular mechanisms by which pioneer transcription factors function and cooperate on chromatin remain unclear. Here we present cryo-electron microscopy structures of human OCT4 bound to a nucleosome containing human LIN28B or nMATN1 DNA sequences, both of which bear multiple binding sites for OCT4. Our structural and biochemistry data reveal that binding of OCT4 induces changes to the nucleosome structure, repositions the nucleosomal DNA and facilitates cooperative binding of additional OCT4 and of SOX2 to their internal binding sites. The flexible activation domain of OCT4 contacts the N-terminal tail of histone H4, altering its conformation and thus promoting chromatin decompaction. Moreover, the DNA-binding domain of OCT4 engages with the N-terminal tail of histone H3, and post-translational modifications at H3K27 modulate DNA positioning and affect transcription factor cooperativity. Thus, our findings suggest that the epigenetic landscape could regulate OCT4 activity to ensure proper cell programming.

The dynamical organization of the core pluripotency transcription factors responds to differentiation cues in early S-phase.

DNA replication in stem cells is a major challenge for pluripotency preservation and cell fate decisions. This process involves massive changes in the chromatin architecture and the reorganization of many transcription-related molecules in different spatial and temporal scales. Pluripotency is controlled by the master transcription factors (TFs) OCT4, SOX2 and NANOG that partition into condensates in the nucleus of embryonic stem cells. These condensates are proposed to play relevant roles in the regulation of gene expression and the maintenance of pluripotency. Here, we asked whether the dynamical distribution of the pluripotency TFs changes during the cell cycle, particularly during DNA replication. Since the S phase is considered to be a window of opportunity for cell fate decisions, we explored if differentiation cues in G1 phase trigger changes in the distribution of these TFs during the subsequent S phase. Our results show a spatial redistribution of TFs condensates during DNA replication which was not directly related to chromatin compaction. Additionally, fluorescence fluctuation spectroscopy revealed TF-specific, subtle changes in the landscape of TF-chromatin interactions, consistent with their particularities as key players of the pluripotency network. Moreover, we found that differentiation stimuli in the preceding G1 phase triggered a relatively fast and massive reorganization of pluripotency TFs in early-S phase. Particularly, OCT4 and SOX2 condensates dissolved whereas the lifetimes of TF-chromatin interactions increased suggesting that the reorganization of condensates is accompanied with a change in the landscape of TF-chromatin interactions. Notably, NANOG showed impaired interactions with chromatin in stimulated early-S cells in line with its role as naïve pluripotency TF. Together, these findings provide new insights into the regulation of the core pluripotency TFs during DNA replication of embryonic stem cells and highlight their different roles at early differentiation stages.

C-terminally phosphorylated p27 drives cancer-promoting inflammation

Abstract p27 normally inhibits cell cycle progression and cell growth. In cancers, deregulated p27 acts as an oncogene to promote metastasis when phosphorylated by PI3K-activated kinases at T157 and T198 (p27pTpT). We showed p27pTpT transcriptionally co-activates cJun and induces STAT3 activation. Here, we pursue the hypothesis that p27pTpT transcriptionally co-activates STAT3 target genes to expand cancer stem cells (CSC) and promote cancer inflammation. In triple negative breast cancer (TNBC) lines, we showed that p27pTpT increases stem cell properties, including sphere formation and expression of stem cell transcription factors MYC, OCT4, NANOG, and KLF4through STAT3. ChIP-seq/RNA-seq showed p27 recruits STAT3 to gene promoters to induce profiles of p27/STAT3 co-target genes, including MYCand JAG1, that increase tumor-initiating stem cells (TISC) in vivo. This work revealed a novel role for p27pTpT as a driver of CSC expansion. Since CSCs mediate treatment resistance, in part, by promoting inflammation, we next tested if p27pTpT drives cancer inflammation. p27/STAT3 co-target genes associate strongly with inflammatory pathways. ATAC-seq/ ChIP-seq showed p27pTpT increased chromatin accessibility to co-recruit p27/STAT3 to promoters of oncogenic, proinflammatory genes (IL-6, NF-κB/RELA, VEGFA)and to mediators of immune evasion. p27pTpT also increased STAT3 activation, p65 (NF-κB subunit), and IL-6 protein levels on WB, and increased CCL2 secretion on ELISA. Notably, both p27 knockdown and STAT3 inhibition decreased p27pTpT-driven CCL2 secretion. Together, these data indicate that when p27 is C-terminally phosphorylated, it acquires a novel oncogenic role to promote STAT3-driven CSC expansion and cancer inflammation.

Therapeutic Potential of Amniotic Fluid-Derived Stem Cells into Pancreatic Lineage in an Animal Model of Diabetes

Diabetes is a major health concern and it is estimated that India became diabetic capital in the future. The therapeutic potential of various medications, cell therapy, and islet transplantation is explored in recent years. The therapeutic potential of Mesenchymal Stem cells (MSCs) from bone marrow and from other sources has been studied forthe treatment of diabetes. MSCsfrom bone marrow ameliorate hyperglycemia but are unable to restore normoglycaemia in diabetic animals when injected with a single dose. The therapeutic potential of another more primitive source of MSCs from human amniotic fluid-derived stem cells (hAFSCs) has not been explored in diabetes. In the present study, we have assessed the effect of hAFSCs in a rat model of diabetes. hAFSCs transplantation has been seen to control blood glucose levels, and promote weight gain and other physiological parameters. Immuno-histochemical results suggested an increase in islet mass and number after hAFSCs transplantation. Q-RTPCR results showed transcription factors Ins-1, Oct-4, MAF-A, and PDX-1 were markedly upregulated in the hAFSCs transplanted group in comparison with diabetes and control groups. These data suggest that hAFSCs possess considerable therapeutic potential for diabetes through the restoration of insulin mass and up regulations of transcription factors of pancreatic lineage. Keyword : Amniotic fluid stem cells, diabetic mellitus, rat