Stem Cell Reprogramming Research Articles

Epigenetic reprogramming of cancer stem cells to tumor cells using ultrasmall gold nanoparticle

Epigenetic reprogramming of cancer stem-like cells (CSC) is crucial to the clinical implementation of efficient tumor management. Groups of methylation on genomic DNA are a relatively stable epigenetic component. They are key drivers in the formation and maintenance of CSCs. Hence, reprogramming the DNA methylation epigenetics can provide new insights into cancer therapeutic approaches. Nanoprobes can influence CSC epigenetics; however, existing nanoprobes induce epigenetic alterations in an unregulated manner, which might result in undesirable mutation accumulation, which can hinder the reprogramming process. Here we report an epigenetic reprogramming approach with an ultrasmall Au NP, which can demethylate the genomic DNA, thereby causing the reprogramming of CSCs to cancer cells. In vitro bench top verification on preclinical models of non-metastatic and metastatic lung CSC showed a significant decrease in genetic, phenotypic stemness, and cell cycle quiescence, validated with biological assays. Furthermore, the ultrasmall Au NP was shown to interact with the epigenetic environment of CSCs through gold-DNA affinity spectral analysis. The pilot clinical validation study established the potential of our approach for clinical implementation. To the best of our knowledge, this is the first study to demonstrate a CSC epigenetic reprogramming using nanoparticles. In summary, this paper demonstrated that the nanoprobe could actively modify epigenetics and, as a result, can be employed to mitigate CSC stemness. Our findings might pave the path for more effective anti-cancer treatments and precision nanomedicine in the future.

Induced pluripotent stem cell for modeling Pompe disease.

Pompe disease (PD) is a rare, autosomal recessive, inherited, and progressive metabolic disorder caused by α-glucosidase defect in lysosomes, resulting in abnormal glycogen accumulation. Patients with PD characteristically have multisystem pathological disorders, particularly hypertrophic cardiomyopathy, muscle weakness, and hepatomegaly. Although the pathogenesis and clinical outcomes of PD are well-established, disease-modeling ability, mechanism elucidation, and drug development targeting PD have been substantially limited by the unavailable PD-relevant cell models. This obstacle has been overcome with the help of induced pluripotent stem cell (iPSC) reprogramming technology, thus providing a powerful tool for cell replacement therapy, disease modeling, drug screening, and drug toxicity assessment. This review focused on the exciting achievement of PD disease modeling and mechanism exploration using iPSC.

LncRNA Osilr9 coordinates promoter DNA demethylation and the intrachromosomal loop structure required for maintaining stem cell pluripotency

Nuclear reprogramming of somatic cells into a pluripotent status has the potential to create patient-specific induced pluripotent stem cells for regenerative medicine. Currently, however, the epigenetic mechanisms underlying this pluripotent reprogramming are poorly understood. To delineate this epigenetic regulatory network, we utilized a chromatin RNA in situ reverse transcription sequencing (CRIST-seq) approach to identify long noncoding RNAs (lncRNAs) embedded in the 3-dimensional intrachromosomal architecture of stem cell core factor genes. By combining CRIST-seq and RNA sequencing, we identified Oct4-Sox2 interacting lncRNA 9 (Osilr9) as a pluripotency-associated lncRNA. Osilr9 expression was associated with the status of stem cell pluripotency in reprogramming. Using short hairpin RNA (shRNA) knockdown, we showed that this lncRNA was required for the optimal maintenance of stem cell pluripotency. Overexpression of Osilr9 induced robust activation of endogenous stem cell core factor genes in fibroblasts. Osilr9 participated in the formation of the intrachromosomal looping required for the maintenance of pluripotency. After binding to the Oct4 promoter, Osilr9 recruited the DNA demethylase ten-eleven translocation 1, leading to promoter demethylation. These data demonstrate that Osilr9 is a critical chromatin epigenetic modulator that coordinates the promoter activity of core stem cell factor genes, highlighting the critical role of pluripotency-associated lncRNAs in stem cell pluripotency and reprogramming.

Reprogramming stem cells in regenerative medicine

AbstractInduced pluripotent stem cells (iPSCs) that are generated from adult somatic cells are induced to express genes that make them pluripotent through reprogramming techniques. With their unlimited proliferative capacity and multifaceted differentiation potential and circumventing the ethical problems encountered in the application of embryonic stem cells (ESC), iPSCs have a broad application in the fields of cell therapy, drug screening, and disease models and may open up new possibilities for regenerative medicine to treat diseases in the future. In this review, we begin with different reprogramming cell technologies to obtain iPSCs, including biotechnological, chemical, and physical modulation techniques, and present their respective strengths, and limitations, as well as the recent progress of research. Secondly, we review recent research advances in iPSC reprogramming‐based regenerative therapies. iPSCs are now widely used to study various clinical diseases of hair follicle defects, myocardial infarction, neurological disorders, liver diseases, and spinal cord injuries. This review focuses on the translational clinical research around iPSCs as well as their potential for growth in the medical field. Finally, we summarize the overall review and look at the potential future of iPSCs in the field of cell therapy as well as tissue regeneration engineering and possible problems. We believe that the advancing iPSC research will help drive long‐awaited breakthroughs in cellular therapy.

Metabolism in Cancer Stem Cells: Targets for Clinical Treatment.

Cancer stem cells (CSCs) have high tumorigenicity, high metastasis and high resistance to treatment. They are the key factors for the growth, metastasis and drug resistance of malignant tumors, and are also the important reason for the occurrence and recurrence of tumors. Metabolic reprogramming refers to the metabolic changes that occur when tumor cells provide sufficient energy and nutrients for themselves. Metabolic reprogramming plays an important role in regulating the growth and activity of cancer cells and cancer stem cells. In addition, the immune cells or stromal cells in the tumor microenvironment (TME) will change due to the metabolic reprogramming of cancer cells. Summarizing the characteristics and molecular mechanisms of metabolic reprogramming of cancer stem cells will provide new ideas for the comprehensive treatment of malignant tumors. In this review, we summarized the changes of the main metabolic pathways in cancer cells and cancer stem cells.

Micro-Topographies Induce Epigenetic Reprogramming and Quiescence in Human Mesenchymal Stem Cells.

Biomaterials can control cell and nuclear morphology. Since the shape of the nucleus influences chromatin architecture, gene expression and cell identity, surface topography can control cell phenotype. This study provides fundamental insights into how surface topography influences nuclear morphology, histone modifications, and expression of histone-associated proteins through advanced histone mass spectrometry and microarray analysis. The authors find that nuclear confinement is associated with a loss of histone acetylation and nucleoli abundance, while pathway analysis reveals a substantial reduction in gene expression associated with chromosome organization. In light of previous observations where the authors found a decrease in proliferation and metabolism induced by micro-topographies, they connect these findings with a quiescent phenotype in mesenchymal stem cells, as further shown by a reduction of ribosomal proteins and the maintenance of multipotency on micro-topographies after long-term culture conditions. Also, this influence of micro-topographies on nuclear morphology and proliferation is reversible, as shown by a return of proliferation when re-cultured on a flat surface. The findings provide novel insights into how biophysical signaling influences the epigenetic landscape and subsequent cellular phenotype.

Histone acetyltransferase 1 (HAT1) acetylates hypoxia-inducible factor 2 alpha (HIF2A) to execute hypoxia response

Hypoxic response to low oxygen levels is characteristic of most solid cancers. Hypoxia-inducible factors (HIFs) regulate cellular metabolism, survival, proliferation, and cancer stem cell growth during hypoxia. The genome-wide analysis identified HAT1, a type B histone acetyltransferase, as an upregulated and essential gene in glioblastoma (GBM). GSEA analysis of differentially regulated genes in HAT1 silenced cells identified significant depletion of “hypoxia” gene sets. Hypoxia conditions induced HIF2A, not HIF1A protein levels in glioma cells in a HAT1-dependent manner. HAT1 and HIF2A interacted with each other and occupied the promoter of VEGFA, a bonafide HIF1A/HIF2A target. Acetylation of K512 and K596 residues by HAT1 is essential for HIF2A stabilization under normoxia and hypoxia as HIF2A carrying acetylation mimic mutations at either of these residues (H512Q or K596Q) showed stable expression in HAT1 silenced cells under normoxia and hypoxia conditions. Finally, we demonstrate that the HAT1-HIF2A axis is essential for hypoxia-promoted cancer stem cell maintenance and reprogramming. Thus, our study identifies that the HAT1-dependent acetylation of HIF2A is vital to executing the hypoxia-induced cell survival and cancer stem cell growth, therefore proposing the HAT1-HIF2A axis as a potential therapeutic target.

The chemical reprogramming of unipotent adult germ cells towards authentic pluripotency and de novo establishment of imprinting.

Although somatic cells can be reprogrammed to pluripotent stem cells (PSCs) with pure chemicals, authentic pluripotency of chemically induced pluripotent stem cells (CiPSCs) has never been achieved through tetraploid complementation assay. Spontaneous reprogramming of spermatogonial stem cells (SSCs) was another non-transgenic way to obtain PSCs, but this process lacks mechanistic explanation. Here, we reconstructed the trajectory of mouse SSC reprogramming and developed a five-chemical combination, boosting the reprogramming efficiency by nearly 80- to 100-folds. More importantly, chemical induced germline-derived PSCs (5C-gPSCs), but not gPSCs and chemical induced pluripotent stem cells, had authentic pluripotency, as determined by tetraploid complementation. Mechanistically, SSCs traversed through an inverted pathway of in vivo germ cell development, exhibiting the expression signatures and DNA methylation dynamics from spermatogonia to primordial germ cells and further to epiblasts. Besides, SSC-specific imprinting control regions switched from biallelic methylated states to monoallelic methylated states by imprinting demethylation and then re-methylation on one of the two alleles in 5C-gPSCs, which was apparently distinct with the imprinting reprogramming in vivo as DNA methylation simultaneously occurred on both alleles. Our work sheds light on the unique regulatory network underpinning SSC reprogramming, providing insights to understand generic mechanisms for cell-fate decision and epigenetic-related disorders in regenerative medicine.

Hypoxia-induced reprogrammed myoblasts enhance the formation of neuromuscular junctions: A pioneer study.

We previously reported that muscle cells could reprogram into progenitors after traumatic injuries. These injury-induced muscle stem cells (iMuSCs) have increased migration and differentiation capacities, including neuronal differentiation. Recent studies in our laboratory suggest that the hypoxia-induced by tissue injury plays an essential role in the reprogramming process of muscle cells. We hypothesize that muscle cells reprogrammed with hypoxia have increased neuronal differentiation potentials and the neuronal differentiation extends into the formation of neuromuscular junction (NMJ)-like structures. In this study, C2C12 myoblasts were cultured under hypoxic conditions and subsequently in neural differentiation media to generate neurospheres, and then with muscle differentiation media to induce NMJ-like structure formation. Hypoxia-induced muscle cells also produced more robust NMJs compared to controls after intramuscular cell transplantation. Our results suggest hypoxia plays a role in the reprogramming of muscle stem cells, which may have the potential to form neuromuscular junctions and ultimately contribute to functional muscle healing.

Abstract IA009: Oncogenic transcription factors drive highly tumor-specific LincRNA

Abstract Many cancers are characterized by gene fusions encoding oncogenic chimeric transcription factors (TFs) such as EWS::FLI1 in Ewing sarcoma (EwS). EWS::FLI1 induces a complete reprogramming of mesenchymal stem cells, the putative cell of origin of Ewing sarcoma, through binding and subsequent generation of thousands of neoenhancers at GGAA microsatellite repeats. We show that EWS::FLI1 induces the robust expression of a specific set of novel spliced and polyadenylated transcripts within otherwise transcriptionally silent regions of the genome. These neo-genes (NGs) are virtually undetectable in large collections of normal tissues or non-EwS tumors and can be silenced by CRISPR interference at regulatory EWS::FLI1-bound microsatellites. Ribosome profiling and proteomics further show that some NGs are translated into highly EwS-specific peptides. More generally, hundreds of NGs can be detected in diverse cancers characterized by chimeric TFs. Altogether, we identify the transcription, processing, and translation of novel, specific, highly expressed multi-exonic transcripts from otherwise silent regions of the genome as a new activity of aberrant TFs in cancer. These neotranscripts, which can be classified as LincRNAs, or neopeptides may have specific functions in the tumor cells. The latter may also constitute ideal neoepitopes as they are tumor-specific, clonally expressed in sarcoma cells, induced by the driver genetic alterations and public for a given sarcoma. Citation Format: Olivier Delattre, Julien Vibert, Olivier Saulnier, Joshua Waterfall. Oncogenic transcription factors drive highly tumor-specific LincRNA [abstract]. In: Proceedings of the AACR Special Conference: Sarcomas; 2022 May 9-12; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(18_Suppl):Abstract nr IA009.

Conservation Biology and Reproduction in a Time of Developmental Plasticity.

The objective of this review is to ask whether, and how, principles in conservation biology may need to be revisited in light of new knowledge about the power of epigenetics to alter developmental pathways. Importantly, conservation breeding programmes, used widely by zoological parks and aquariums, may appear in some cases to reduce fitness by decreasing animals’ abilities to cope when confronted with the ‘wild side’ of their natural habitats. Would less comfortable captive conditions lead to the selection of individuals that, despite being adapted to life in a captive environment, be better able to thrive if relocated to a more natural environment? While threatened populations may benefit from advanced reproductive technologies, these may actually induce undesirable epigenetic changes. Thus, there may be inherent risks to the health and welfare of offspring (as is suspected in humans). Advanced breeding technologies, especially those that aim to regenerate the rarest species using stem cell reprogramming and artificial gametes, may also lead to unwanted epigenetic modifications. Current knowledge is still incomplete, and therefore ethical decisions about novel breeding methods remain controversial and difficult to resolve.

Recent insights into the microRNA and long non-coding RNA-mediated regulation of stem cell populations.

Stem cells are undifferentiated cells that have multi-lineage differentiation. The transition from self-renewal to differentiation requires rapid and extensive gene expression alterations. Since different stem cells exhibit diverse non-coding RNAs (ncRNAs) expression profiles, the critical roles of ncRNAs in stem cell reprogramming, pluripotency maintenance, and differentiation have been widely investigated over the past few years. Hence, in this current review, the two main categories of ncRNAs, microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), are discussed. While the primary way by which miRNAs restrict mRNA transcription is through miRNA-mRNA interaction, lncRNAs have a wide range of effects on mRNA functioning, including interactions with miRNAs. Both of these ncRNAs participate in the post-transcriptional regulation of crucial biological mechanisms, such as cell cycle regulation, apoptosis, aging, and cell fate decisions. These findings shed light on a previously unknown aspect of gene regulation in stem cell fate determination and behavior. Overall, we summarized the key roles of miRNAs (including exosomal miRNAs) and lncRNAs in the regulation of stem cell populations, such as cardiac, hematopoietic, mesenchymal, neural, and spermatogonial, as well ncRNAs' influence on malignancy through modulating cancer stem cells, which might significantly contribute to clinical stem cell therapy and in regenerative medicine.

The use of pluripotent stem cells to generate diagnostic tools for transfusion medicine

AbstractRed blood cell (RBC) transfusion is one of the most common medical treatments, with more than 10 million units transfused per year in the United States alone. Alloimmunization to foreign Rh proteins (RhD and RhCE) on donor RBCs remains a challenge for transfusion effectiveness and safety. Alloantibody production disproportionately affects patients with sickle cell disease who frequently receive blood transfusions and exhibit high genetic diversity in the Rh blood group system. With hundreds of RH variants now known, precise identification of Rh antibody targets is hampered by the lack of appropriate reagent RBCs with uncommon Rh antigen phenotypes. Using a combination of human-induced pluripotent stem cell (iPSC) reprogramming and gene editing, we designed a renewable source of cells with unique Rh profiles to facilitate the identification of complex Rh antibodies. We engineered a very rare Rh null iPSC line lacking both RHD and RHCE. By targeting the AAVS1 safe harbor locus in this Rh null background, any combination of RHD or RHCE complementary DNAs could be reintroduced to generate RBCs that express specific Rh antigens such as RhD alone (designated D--), Goa+, or DAK+. The RBCs derived from these iPSCs (iRBCs) are compatible with standard laboratory assays used worldwide and can determine the precise specificity of Rh antibodies in patient plasma. Rh-engineered iRBCs can provide a readily accessible diagnostic tool and guide future efforts to produce an alternative source of rare RBCs for alloimmunized patients.

Investigation of Signals and Transcription Factors for The Generation of Female Germ-Like Cells.

Objective Primordial germ cell (PGCs) lines are a source of a highly specialized type of cells, characteristically oocytes, during female germline development in vivo. The oocyte growth begins in the transition from the primary follicle. It is associated with dynamic changes in gene expression, but the gene-regulating signals and transcription factors that control oocyte growth remain unknown. We aim to investigate the differentiation potential of mouse bone marrow mesenchymal stem cells (mMSCs) into female germ-like cells by testing several signals and transcription factors. Materials and Methods In this experimental study, mMSCs were extracted from mice femur bone using the flushing technique. The cluster-differentiation (CD) of superficial mesenchymal markers was determined with flow cytometric analysis. We applied a set of transcription factors including retinoic acid (RA), titanium nanotubes (TNTs), and fibrin such as TNT-coated fibrin (F+TNT) formation and (RA+F+TNT) induction, and investigated the changes in gene, MVH/ DDX4, expression and functional screening using an in vitro mouse oocyte development condition. Germ cell markers expression, (MVH / DDX4), was analyzed with Immunocytochemistry staining, quantitative transcription-polymerase chain reaction (RT-qPCR) analysis, and Western blots. Results The expression of CD was confirmed by flow cytometry. The phase determination of the TNTs and F+TNT were confirmed using x-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. Remarkably, applying these transcription factors quickly induced pluripotent stem cells into oocyte-like cells that were sufficient to generate female germ- like cells, growth, and maturation from mMSCs differentiation. These transcription factors formed oocyte-like cells specification of stem cells, epigenetic reprogramming, or meiosis and indicate that oocyte meiosis initiation and oocyte growth are not separable from the previous epigenetic reprogramming in stem cells in vitro. ConclusionResults suggested several transcription factors may apply for arranging oocyte-like cell growth and supplies an alternative source of in vitro maturation (IVM).

Lineage reprogramming of human adipose mesenchymal stem cells to immune modulatory i-Heps.

Pluripotent stem cell derived-hepatocytes depict fetal -hepatocyte characteristics/maturity and are immunogenic limiting their applications. Attempts have been made to derive hepatocytes from mesenchymal stem cells using developmental cocktails, epigenetic modulators and small molecules. However, achieving a stable terminally differentiated functional state had been a challenge. Inefficient hepatic differentiation could be due to lineage restrictions set during development. Hence a novel lineage reprogramming approach has been utilized to confer competence to adipose-mesenchymal stem cells (ADMSCs) to efficiently respond to hepatogenic cues and achieve a stable functional hepatic state. Lineage reprogramming involved co-transduction of ADMSCs with hepatic endoderm pioneer Transcription factor (TF)-FOXA2, HHEX-a homeobox gene and HNF4α-master TF indispensable for hepatic state maintenance. Lineage priming was evidenced by endogenous HFN4α promoter demethylation and robust responsiveness to minimal hepatic maturation cues. Induced hepatocytes (i-Heps) exhibited mesenchymal-to-epithelial transition and terminal hepatic signatures. Functional characterisation of i-Heps for hepatic drug detoxification systems, xenobiotic uptake/clearance, metabolic status and hepatotropic virus entry validated acquisition of stable hepatic state and junctional maturity Exhaustive analysis of MSC memory in i-Heps indicated loss of MSC-immunophenotype and terminal differentiation to osteogenic/adipogenic lineages. Importantly, i-Heps suppressed phytohemagglutinin-induced T-cell blasts, inhibited allogenic mixed-lymphocyte reactions (MLRs) and secreted immunomodulatory- indoleamine 2,3-dioxygenase in T-cell blast co-cultures akin to native ADMSCs. In a nutshell, the present study identifies a novel cocktail of TFs that reprogram ADMSCs to stable hepatic state. i-Heps exhibit adult hepatocyte functional maturity with robust immune-modulatory abilities rendering suitability for rigorous drug testing, hepatocyte-pathogen interaction studies and transplantation in allogenic settings.

Nuclear-localized, iron-bound superoxide dismutase-2 antagonizes epithelial lineage programs to promote stemness of breast cancer cells via a histone demethylase activity

The dichotomous behavior of superoxide dismutase-2 (SOD2) in cancer biology has long been acknowledged and more recently linked to different posttranslational forms of the enzyme. However, a distinctive activity underlying its tumor-promoting function is yet to be described. Here, we report that acetylation, one of such posttranslational modifications (PTMs), increases SOD2 affinity for iron, effectively changing the biochemical function of this enzyme from that of an antioxidant to a demethylase. Acetylated, iron-bound SOD2 localizes to the nucleus, promoting stem cell gene expression via removal of suppressive epigenetic marks such as H3K9me3 and H3K927me3. Particularly, H3K9me3 was specifically removed from regulatory regions upstream of Nanog and Oct-4, two pluripotency factors involved in cancer stem cell reprogramming. Phenotypically, cells expressing nucleus-targeted SOD2 (NLS-SOD2) have increased clonogenicity and metastatic potential. FeSOD2 operating as H3 demethylase requires H2O2 as substrate, which unlike cofactors of canonical demethylases (i.e., oxygen and 2-oxoglutarate), is more abundant in tumor cells than in normal tissue. Therefore, our results indicate that FeSOD2 is a demethylase with unique activities and functions in the promotion of cancer evolution toward metastatic phenotypes.

Evaluation of the Impact of Pregnancy-Associated Factors on the Quality of Wharton's Jelly-Derived Stem Cells Using SOX2 Gene Expression as a Marker.

SOX2 is a recognized pluripotent transcription factor involved in stem cell homeostasis, self-renewal and reprogramming. It belongs to, one of the SRY-related HMG-box (SOX) family of transcription factors, taking part in the regulation of embryonic development and determination of cell fate. Among other functions, SOX2 promotes proliferation, survival, invasion, metastasis, cancer stemness, and drug resistance. SOX2 interacts with other transcription factors in multiple signaling pathways to control growth and survival. The aim of the study was to determine the effect of a parturient’s age, umbilical cord blood pH and length of pregnancy on the quality of stem cells derived from Wharton’s jelly (WJSC) by looking at birth weight and using SOX2 gene expression as a marker. Using qPCR the authors, evaluated the expression of SOX2 in WJSC acquired from the umbilical cords of 30 women right after the delivery. The results showed a significant correlation between the birth weight and the expression of SOX2 in WJSC in relation to maternal age, umbilical cord blood pH, and the length of pregnancy. The authors observed that the younger the woman and the lower the umbilical cord blood pH, the earlier the delivery occurs, the lower the birth weight and the higher SOX2 gene expression in WJSC. In research studies and clinical applications of regenerative medicine utilizing mesenchymal stem cells derived from Wharton’s Jelly of the umbilical cord, assessment of maternal and embryonic factors influencing the quality of cells is critical.

MiR-106b-5p Regulates the Reprogramming of Spermatogonial Stem Cells into iPSC (Induced Pluripotent Stem Cell)-Like Cells

Background:Recent years have brought notable progress in raising the efficiency of the reprogramming technique so that approaches have evolved from known transgenic factors to only a few miRNAs. Nevertheless, there is a poor understanding of both the key factors and biological networks underlying this reprogramming. The present study aimed to investigate the potential of miR-106b-5p in regulating SSCs to iPSC-like cells. Methods:We used SSCs because pluripotency is inducible in SSCs under defined culture conditions, and they have a few issues compared to other adult stem cells. As both signaling and post-transcriptional gene controls are critical for pluripotency regulation, we traced the expression of OSKMN. Besides, we considered miR-106b-5p targets using bioinformatic methods. Results:Our results showed that transfected SSCs with miR-106b-5p increased the expression of the OSKMN factors, which was significantly more than negative control groups. Moreover, using the functional miRNA enrichment analysis, online tools, and databases, we predicted that miR-106b-5p targeted a signaling pathway gene named MAPK1/ERK2, related to regulating stem cell pluripotency. Conclusion:Together, our data suggest that miR-106b-5p regulates the reprogramming of SSCs into iPSC-like cells. Furthermore, noteworthy progress in the in vitro development of SSCs indicates promise reservoirs and opportunities for future clinical trials.

Abstract 5830: Carcinogenic effects of metal and metalloids through epigenetic reprogramming of human bone marrow stem cells: The bioinformatics database analysis

Abstract Many scientific studies showed that the carcinogenic effects of environmental contamination of several metal and metalloids on bone marrow stem cells of human body. These carcinogens include, Cadmium, Mercury, Chromium, Aluminum, Nickel and Arsenic. However, there was no such analysis for elucidating the mechanism of carcinogenic effects and epigenetic reprogramming of human bone marrow stem cells. In this study, we analyzed the carcinogenic effects of mentioned carcinogens, and the mechanism of epigenetic reprogramming using NIH Toxicology Data Network (TOXNET), Comparative Toxico-genomics Database (CTD), AACR Genomics Evidence Neoplasia Information Exchange (GENIE) database, database of Environmental Health Perspectives (EHP), National Institute of Environmental Health Sciences (NIEHS), and other bioinformatics database. We found from CTD analysis that the chemical gene interactions showed highly expressed of 272 common genes with miR140 by Cadmium, Mercury from total 3704 genes (approximately 7% affected genes). The AACR GENIE database analysis showed CDKN3, is associated with bone cancer (2 clinical data), HDAC7, TP53, MAPK3K1, MAP2K2 (8 clinical data) found among 272 genes regulated by Cadmium and Mercury. The CTD analysis showed the chemical gene interactions of highly expressed of 102 common genes with miR140 by Chromium, Mercury from a total of 1406 genes; 268 common genes with CD84, CD226 by Mercury, Nickel from a total of 5032 genes; 103 common genes with CD226 by Aluminum, Mercury from a total of 2556 genes; 248 common genes by Arsenic, Mercury from total 5508 genes. Among these 5508 genes, 248 common genes with ALDHA1, 247 common genes with CD40, 248 common genes with CD44, 247 common genes with CD423, 247 common genes with miR10A by Arsenic, Mercury from total 2556 genes. The epigenetic mechanisms of histone modifications (H3K9me3, H3K27me3, H3K27ac, H3K36me3, H3K4me1, H3K4me3 of B cells, hemopoietic stem cells, mesenchymal bone marrow, and chondrocyte stem cells and miRNAs) and these carcinogens have been revealed by the database of EHP, NIEHS, the NIH Roadmap Epigenomics Mapping Consortium, the National Center for Biotechnology Information (NCBI), and U.S. National Library of Medicine (NLM) database. Our previous study reported that the regulation of epigenetic bivalent histone modifications at transcript starts sequences (TSS) of target genes for heterogenic adult stem cells (CSCs)reprogramming and our current bioinformatics analysis revealed that TP53 is epigenetically reprogrammed with close interaction of thirteen genes by these carcinogens. Therefore, it is important to find the actual epigenetic mechanism both genomic and epigenomic transcriptional regulation and carcinogenic effects of these carcinogens on bone marrow stem cells, and our current study revealed this important relationship. Citation Format: Benedrica Solomon, Richgena Sturrup, Jada Dixon, Kiyona Jackson, Biancaliz Cruz, Charlissia Ferguson, Taylor Walker, Ralph Elisson, Nathan Harris, Jesennia Bonilla, Rose Mary Stiffin, Marilyn Sherman, Alessandra Manzon, Swarnava Das, Madhumita Das, Jayanta Kumar Das. Carcinogenic effects of metal and metalloids through epigenetic reprogramming of human bone marrow stem cells: The bioinformatics database analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5830.

Autophagy reprogramming stem cell pluripotency and multiple-lineage differentiation.

The cellular process responsible for the degradation of cytosolic proteins and subcellular organelles in lysosomes was termed "autophagy." This process occurs at a basal level in most tissues as part of tissue homeostasis that redounds to the regular turnover of components inside cytoplasm. The breakthrough in the autophagy field is the identification of key players in the autophagy pathway, compounded under the name "autophagy-related genes" (ATG) encoding for autophagy effector proteins. Generally, the function of autophagy can be classified into two divisions: intracellular clearance of defective macromolecules and organelles and generation of degradation products. Therapeutic strategies using stem cell-based approach come as a promising therapy and develop rapidly recently as stem cells have high self-renewability and differentiation capability as known as mesenchymal stem cells (MSCs). They are defined as adherent fibroblast-like population with the abilities to self-renew and multi-lineage differentiate into osteogenic, adipogenic, and chondrogenic lineage cells. To date, they are the most extensively applied adult stem cells in clinical trials. The properties of MSCs, such as immunomodulation, neuroprotection, and tissue repair pertaining to cell differentiation, processes to replace lost, or damaged cells, for aiding cell repair and revival. Autophagy has been viewed as a remarkable mechanism for maintaining homeostasis, ensuring the adequate function and survival of long-lived stem cells. In addition, authophagy also plays a remarkable role in protecting stem cells against cellular stress when the stem cell regenerative capacity is harmed in aging and cellular degeneration. Understanding the under-explored mechanisms of MSC actions and expanding the spectrum of their clinical applications may improve the utility of the MSC-based therapeutic approach in the future.