BACKGROUND:Aberrant DNA methylation biomarkers have demonstrated potential for early cancer detection, multicancer detection, and determining the tissue of origin. Due to their stability, frequency, and accessibility in bodily fluids, circulating cell-free DNA (cfDNA) methylation is a promising biomarker in liquid biopsy. A reliable and quantifiable analysis of cfDNA methylation status is critical to its application. However, there are current challenges and a lack of consensus on measurement methods. To address this, we developed two candidate methylated cfDNA reference materials (RMs). METHODS:The National Institute of Standards and Technology (NIST) RM consists of five components, formulated by mixing in vitro methylated cfDNA simulant at fractions of 0%, 5%, 25%, 50%, and 100% with native-state cfDNA simulant derived from the GM24385 cell line. The LGC Clinical Diagnostics (LGC) RM consists of two components: non-methylated cfDNA simulant derived from GM24385 genomic DNA and whole genome amplification and methylated cfDNA produced by in vitro methylation of amplified material. The candidate RMs were characterized, and the methylation status of three targets was confirmed by droplet digital PCR (ddPCR) assays. To test the utility of these RMs, six laboratories participated in an interlaboratory study, each using their own lab-developed assays and methods, which included methylation-specific qPCR, nanoplate digital PCR (dPCR), ddPCR, matrix methylated DNA immunoprecipitation-based assays, and whole-genome bisulfite sequencing. RESULTS:The interlaboratory study results showed that the designed percentage of methylation was well correlated with the observed values across all participating labs, and good reproducibility was found for each individual method. However, slightly different methylation proportions associated with assay-specific biases were observed. CONCLUSIONS:This study clearly demonstrates the value of candidate RMs as standards for evaluating assay performance, as well as for increasing confidence in reporting cfDNA methylation status for clinical applications.

Directed differentiation of pluripotent stem cells (PSCs) into pancreatic islets is a cornerstone strategy for diabetes cell therapy. This process relies on growth factor-driven activation of core transcriptional regulators, notably PDX1 and NGN3, to restrict the multi-lineage potential of definitive endoderm to pancreatic progenitors and endocrine cell types. Yet differentiation efficiency and lineage fidelity vary markedly across PSC lines. Here, we demonstrate that a dominant constraint is persistent Polycomb Repressive Complex 2 (PRC2)-mediated epigenetic repression at the PDX1 and NGN3 loci, limiting endocrine specification despite inductive signaling. To directly test whether chromatin states at the PDX1 and NGN3 loci gate developmental competence, we deployed a computationally engineered epigenetic effector (EBdCas9) to transiently and sequentially remove H3K27me3 at those loci during defined developmental windows. Targeted epigenetic resolution robustly enhanced endocrine lineage commitment and accelerated β-cell differentiation across genetically diverse PSC lines. In contrast, direct transcriptional activation with VP64dCas9 increased PDX1 and NGN3 expression but did not improve differentiation outcomes. Integrated cell population studies and genome-wide chromatin and transcriptomic analyses reveal that PRC2-targeted remodeling preferentially activates endocrine gene networks while limiting progenitor expansion and lineage-inappropriate programs. These findings establish that gene-targeted manipulation of PRC2-mediated repression at PDX1 and NGN3 can be used to control cell lineage competence. Collectively, our study reframes variability in PSC differentiation as a failure of epigenetic resolution rather than transcriptional insufficiency and introduces locus-specific chromatin remodeling as a generalizable strategy to enforce developmental fidelity.

Oral facial cleft (OFC) comprises cleft lip with or without cleft palate (CL/P) or cleft palate only. Genome wide association studies (GWAS) of isolated OFC have identified common single nucleotide polymorphisms (SNPs) in many genomic loci where the presumed effector gene (for example, IRF6 in the 1q32 locus) is expressed in embryonic oral epithelium. To identify candidates for functional SNPs at eight such loci we conduct a massively parallel reporter assay in a fetal oral epithelial cell line, revealing SNPs with allele-specific effects on enhancer activity. We filter these SNPs against chromatin-mark evidence of enhancers and test a subset in traditional reporter assays, which support the candidacy of SNPs at loci containing FOXE1, IRF6,  MAFB, TFAP2A, and TP63. For two SNPs near IRF6 and one near FOXE1, we engineer the genome of induced pluripotent stem cells, differentiate the cells into embryonic oral epithelium, and discover allele-specific effects on the levels of effector gene expression, and, in two cases, the binding affinity of transcription factors FOXE1 or ETS2. Conditional analyses of GWAS data suggest the two functional SNPs near IRF6 account for the majority of risk for CL/P at this locus. This study connects genetic variation associated with OFC to mechanisms of pathogenesis.

Precision oncology is driven by biomarkers. For glioblastoma multiforme (GBM), the most common malignant adult primary brain tumor, O6-methylguanine-DNA methyltransferase (MGMT) gene promoter methylation is an important prognostic and treatment clinical biomarker. Time-consuming preanalytical steps such as biospecimen storage, fixation, sampling, and processing are sources of data irreproducibility, and all these preanalytical variables are confounded by intratumor heterogeneity of MGMT promoter methylation. To assess the effect of preanalytical variables on GBM DNA methylation, tissue storage/sampling (CryoGrid), sample preparation multisonicator (PIXUL), and 5-methylcytosine DNA immunoprecipitation (Matrix-MeDIP-qPCR/seq) platforms were used. MGMT promoter methylation status assayed by MeDIP-qPCR was validated with methylation-specific polymerase chain reaction. MGMT promoter methylation levels in frozen and formalin-fixed paraffin-embedded sample pairs were not statistically different, confirming the reliability of formalin-fixed paraffin-embedded for MGMT promoter methylation analysis. Warm ex vivo ischemia (up to 4 hours at 37 °C) and 3 cycles of repeated sample thawing and freezing did not statistically impact 5-methylcytosine at MGMT promoter, exon, and enhancer regions, indicating the resistance of DNA methylation to common variations in sample processing conditions that might be encountered in research and clinical settings. Twenty-six percent to 34% of specimens exhibited intratumor heterogeneity in the MGMT DNA promoter methylation. These data demonstrate that variations in sample fixation, ischemia duration and temperature, and DNA methylation assay technique do not have a statistically significant impact on MGMT promoter methylation assessment. However, intratumor methylation heterogeneity underscores the value of multiple biopsies at different GBM geographic tumor sites in the evaluation of MGMT promoter methylation status. Matrix-MeDIP-seq analysis revealed that MGMT promoter methylation status clustered with other differentially methylated genomic loci (eg, HOXA and lncRNAs) that are resilient to variation in the above preanalytical conditions. These observations offer new opportunities to develop more granular data-based epigenetic GBM biomarkers. In this regard, the high-throughput CryoGrid-PIXUL-Matrix toolbox could be useful.

Adult humans cannot regenerate the enamel-forming cell type, ameloblasts. Hence, human induced pluripotent stem cell (hiPSC)-derived ameloblasts are valuable for investigating tooth development and regeneration. Here, we present a protocol for generating three-dimensional induced early ameloblasts (ieAMs) utilizing serum-free media and growth factors. We describe steps for directing hiPSCs toward oral epithelium and then toward ameloblast fate. These cells can form suspended early ameloblast organoids. This approach is critical for understanding, treating, and promoting regeneration in diseases like amelogenesis imperfecta.For complete details on the use and execution of this protocol, please refer to Alghadeer et al.1

Stem cells' properties are maintained and regulated by a series of signaling pathways. Exploring more about the role of these pathways remains indispensable in modern stem cell applications. Advancement in techniques revealed that stem cells can be used for treating various diseases. There are sundry of signaling pathways intricated in stem cell regulation, which need to be analyzed in detail for the stem cell applications. Hedgehog (Hh) signaling, one of the crucial signaling pathways, is implicated in several stem cell properties. Furthermore, Hh acts as an upstream pathway regulating other significant pathways such as Wnt, Notch, and TGF-β. Identifying and analyzing this interaction between Hh and other pathways are mandatory to understand their implications in various diseases. This chapter deals with the analysis of interaction of Hh with other pathways and to disclose the role played by Wnt, Notch, and TGF-β as targets of Hedgehog pathway in stem cells.

Large-scale high-dimensional multiomics studies are essential to unravel molecular complexity in health and disease. We developed an integrated system for tissue sampling (CryoGrid), analytes preparation (PIXUL), and downstream multiomic analysis in a 96-well plate format (Matrix), MultiomicsTracks96, which we used to interrogate matched frozen and formalin-fixed paraffin-embedded (FFPE) mouse organs. Using this system, we generated 8-dimensional omics data sets encompassing 4 molecular layers of intracellular organization: epigenome (H3K27Ac, H3K4m3, RNA polymerase II, and 5mC levels), transcriptome (messenger RNA levels), epitranscriptome (m6A levels), and proteome (protein levels) in brain, heart, kidney, and liver. There was a high correlation between data from matched frozen and FFPE organs. The Segway genome segmentation algorithm applied to epigenomic profiles confirmed known organ-specific superenhancers in both FFPE and frozen samples. Linear regression analysis showed that proteomic profiles, known to be poorly correlated with transcriptomic data, can be more accurately predicted by the full suite of multiomics data, compared with using epigenomic, transcriptomic, or epitranscriptomic measurements individually.

Genome wide association studies of isolated orofacial cleft (OFC) have identified common single nucleotide polymorphisms (SNPs) at the 1q32/ IRF6 locus and seven other loci where, like IRF6 , the presumed OFC-relevant gene is expressed in oral epithelium. To identify the functional subset of SNPs at these loci we conducted a massively parallel reporter assay (MPRA) in a cell line derived from fetal oral mucosa. This assay identified SNPs with allele-specific effects on reporter activity levels at all eight loci; at four of the loci, these SNPs were within chromatin marked as an active enhancer in human embryonic faces. Results from traditional luciferase reporter assays concorded with those from the MPRA at nine of eleven SNPs tested. We separately engineered two promising SNPs from the 1q32/ IRF6 locus to homozygosity in the genome of induced pluripotent stem cells and then differentiated the cells into embryonic oral epithelium. We found that cells homozygous for the risk-associated alleles had lower levels of IRF6 expression, and that these alleles favored the binding of transcriptional repressors, FOXE1 and ETS2, respectively. Mutations in FOXE1 also cause a syndromic form of OFC, and ETS2 suppresses differentiation of epithelia. Conditional analyses of a meta-analysis of multi-ethnic genome wide association studies suggest that the two SNPs account for the majority of risk for OFC associated with variation at 1q32/ IRF6 . This study connects genetic variation associated with orofacial cleft to mechanisms of pathogenesis. ### Competing Interest Statement KB is co-founder of Matchstick Technologies, Inc. KB is a co-inventor of PIXUL (US Patents 10809166, 11592366).

In Finland the frequency of isolated cleft palate (CP) is higher than that of isolated cleft lip with or without cleft palate (CL/P). This trend contrasts to that in other European countries but its genetic underpinnings are unknown. We performed a genome-wide association study for orofacial clefts, which include CL/P and CP, in the Finnish population. We identified rs570516915, a single nucleotide polymorphism that is highly enriched in Finns and Estonians, as being strongly associated with CP (P= 5.25 × 10-34, OR = 8.65, 95% CI 6.11-12.25), but not with CL/P (P= 7.2 × 10-5), with genome-wide significance. The risk allele frequency of rs570516915 parallels the regional variation of CP prevalence in Finland, and the association was replicated in independent cohorts of CP cases from Finland (P= 8.82 × 10-28) and Estonia (P= 1.25 × 10-5). The risk allele of rs570516915 disrupts a conserved binding site for the transcription factor IRF6 within a previously characterized enhancer upstream of theIRF6gene. Through reporter assay experiments we found that the risk allele of rs570516915 diminishes the enhancer activity. Oral epithelial cells derived from CRISPR-Cas9 edited induced pluripotent stem cells demonstrate that the CP-associated allele of rs570516915 concomitantly decreases the binding of IRF6 and the expression level ofIRF6, suggesting impairedIRF6autoregulation as a molecular mechanism underlying the risk for CP.

In Finland, the frequency of isolated cleft palate (CP) is higher than that of isolated cleft lip with or without cleft palate (CL/P). This trend contrasts to that in other European countries but its genetic underpinnings are unknown. We conducted a genome-wide association study in the Finnish population and identified rs570516915, a single nucleotide polymorphism highly enriched in Finns, as strongly associated with CP (P = 5.25 x 10-34, OR = 8.65, 95% CI 6.11-12.25), but not with CL/P (P = 7.2 x 10-5), with genome-wide significance. The risk allele frequency of rs570516915 parallels the regional variation of CP prevalence in Finland, and the association was replicated in independent cohorts of CP cases from Finland (P = 8.82 x 10-28) and Estonia (P = 1.25 x 10-5). The risk allele of rs570516915 alters a conserved binding site for the transcription factor IRF6 within an enhancer (MCS-9.7) upstream of the IRF6 gene and diminishes the enhancer activity. Oral epithelial cells derived from CRISPR-Cas9 edited induced pluripotent stem cells demonstrate that the CP-associated allele of rs570516915 concomitantly decreases the binding of IRF6 and the expression level of IRF6, suggesting impaired IRF6 autoregulation as a molecular mechanism underlying the risk for CP. Here, the authors perform a genome-wide study and identify a genetic variant enriched in the Finnish population that is strongly associated with isolated cleft palate. This finding suggests a genetic basis for the high prevalence of cleft palate in Finland.

Tooth enamel secreted by ameloblasts (AMs) is the hardest material in the human body, acting as a shield to protect the teeth. However, the enamel is gradually damaged or partially lost in over 90% of adults and cannot be regenerated due to a lack of ameloblasts in erupted teeth. Here, we use single-cell combinatorial indexing RNA sequencing (sci-RNA-seq) to establish a spatiotemporal single-cell census for the developing human tooth and identify regulatory mechanisms controlling the differentiation process of human ameloblasts. We identify key signaling pathways involved between the support cells and ameloblasts during fetal development and recapitulate those findings in human ameloblast in vitro differentiation from induced pluripotent stem cells (iPSCs). We furthermore develop a disease model of amelogenesis imperfecta in a three-dimensional (3D) organoid system and show AM maturation to mineralized structure in vivo. These studies pave the way for future regenerative dentistry.

Over 90% of the U.S. adult population suffers from tooth structure loss due to caries. Most of the mineralized tooth structure is composed of dentin, a material produced and mineralized by ectomesenchyme derived cells known as odontoblasts. Clinicians, scientists, and the general public share the desire to regenerate this missing tooth structure. To bioengineer missing dentin, increased understanding of human tooth development is required. Here we interrogate at the single cell level the signaling interactions that guide human odontoblast and ameloblast development and which determine incisor or molar tooth germ type identity. During human odontoblast development, computational analysis predicts that early FGF and BMP activation followed by later HH signaling is crucial. Here we generate a differentiation protocol based on this sci-RNA-seq analysis to produce mature hiPSC derived odontoblasts in vitro (iOB). Further, we elucidate the critical role of FGF signaling in odontoblast maturation and biomineralization capacity using the de novo designed FGFR1/2c isoform mini binder scaffold C6. Using computational tools, we show on a molecular level how human molar development is delayed compared to incisors. We reveal that enamel knot development is guided by FGF and WNT in incisors and BMP and ROBO in the molars, and that incisor and molar ameloblast development is guided by FGF, EGF and BMP signaling, with tooth type specific intensity of signaling interactions. Dental ectomesenchyme derived cells are the primary source of signaling ligands responsible for both enamel knot and ameloblast development.

Background Disease molecular complexity requires high throughput workflows to map disease pathways through analysis of vast tissue repositories. Great progress has been made in tissue multiomics analytical technologies. To match the high throughput of these advanced analytical platforms, we have previously developed a multipurpose 96-well microplate sonicator, PIXUL, that can be used in multiple workflows to extract analytes from cultured cells and tissue fragments for various downstream molecular assays. And yet, the sample preparation devices, such as PIXUL, along with the downstream multiomics analytical capabilities have not been fully exploited to interrogate tissues because storing and sampling of such biospecimens remain, in comparison, inefficient. Results To mitigate this tissue interrogation bottleneck, we have developed a low-cost user-friendly system, CryoGrid, to catalog, cryostore and sample tissue fragments. TRIzol is widely used to isolate RNA but it is labor-intensive, hazardous, requires fume-hoods, and is an expensive reagent. Columns are also commonly used to extract RNA but they involve many steps, are prone to human errors, and are also expensive. Both TRIzol and column protocols use test tubes. We developed a microplate PIXUL-based TRIzol-free and column-free RNA isolation protocol that uses a buffer containing proteinase K (PK buffer). We have integrated the CryoGrid system with PIXUL-based PK buffer, TRIzol, and PureLink column methods to isolate RNA for gene-specific qPCR and genome-wide transcript analyses. CryoGrid-PIXUL, when integrated with either PK buffer, TRIzol or PureLink column RNA isolation protocols, yielded similar transcript profiles in frozen organs (brain, heart, kidney and liver) from a mouse model of sepsis. Conclusions RNA isolation using the CryoGrid-PIXUL system combined with the 96-well microplate PK buffer method offers an inexpensive user-friendly high throughput workflow to study transcriptional responses in tissues in health and disease as well as in therapeutic interventions.

Cancer is the culmination of many complex disease states affecting multiple organs. Primary diagnosis involves the utilization of prognostic cancer markers to evaluate the likelihood of systemic disease progression. However, the establishment of animal models for aid in cancer research has exploded in recent years. Multiomics analysis unveiled the sequence of cancer development, while animal model research established the pathophysiology of cancer. Recently, the application of stromal and pluripotent stem cells in cancer development has garnered considerable interest. This chapter contributes an overview of the animal models currently employed for determining the role of stem cells derived from various sources in cancer studies. We also address how a better knowledge of stem cell activity can lead to novel cancer detection and treatment strategies and the chapter also discusses on some of the most current animal models and concepts in cancer research.

Background The multiome is an integrated assembly of distinct classes of molecules and molecular properties, or “omes,” measured in the same biospecimen. Freezing and formalin-fixed paraffin-embedding (FFPE) are two common ways to store tissues, and these practices have generated vast biospecimen repositories. However, these biospecimens have been underutilized for multi-omic analysis due to the low throughput of current analytical technologies that impede large-scale studies. Methods Tissue sampling, preparation, and downstream analysis were integrated into a 96-well format multi-omics workflow, MultiomicsTracks96. Frozen mouse organs were sampled using the CryoGrid system, and matched FFPE samples were processed using a microtome. The 96-well format sonicator, PIXUL, was adapted to extract DNA, RNA, chromatin, and protein from tissues. The 96-well format analytical platform, Matrix, was used for chromatin immunoprecipitation (ChIP), methylated DNA immunoprecipitation (MeDIP), methylated RNA immunoprecipitation (MeRIP), and RNA reverse transcription (RT) assays followed by qPCR and sequencing. LC-MS/MS was used for protein analysis. The Segway genome segmentation algorithm was used to identify functional genomic regions, and linear regressors based on the multi-omics data were trained to predict protein expression. Results MultiomicsTracks96 was used to generate 8-dimensional datasets including RNA-seq measurements of mRNA expression; MeRIP-seq measurements of m6A and m5C; ChIP-seq measurements of H3K27Ac, H3K4m3, and Pol II; MeDIP-seq measurements of 5mC; and LC-MS/MS measurements of proteins. We observed high correlation between data from matched frozen and FFPE organs. The Segway genome segmentation algorithm applied to epigenomic profiles (ChIP-seq: H3K27Ac, H3K4m3, Pol II; MeDIP-seq: 5mC) was able to recapitulate and predict organ-specific super-enhancers in both FFPE and frozen samples. Linear regression analysis showed that proteomic expression profiles can be more accurately predicted by the full suite of multi-omics data, compared to using epigenomic, transcriptomic, or epitranscriptomic measurements individually. Conclusions The MultiomicsTracks96 workflow is well suited for high dimensional multi-omics studies – for instance, multiorgan animal models of disease, drug toxicities, environmental exposure, and aging as well as large-scale clinical investigations involving the use of biospecimens from existing tissue repositories.

Bifurcation of cellular fates, a critical process in development, requires histone 3 lysine 27 methylation (H3K27me3) marks propagated by the polycomb repressive complex 2 (PRC2). However, precise chromatin loci of functional H3K27me3 marks are not yet known. Here, we identify critical PRC2 functional sites at high resolution. We fused a computationally designed protein, EED binder (EB), which competes with EZH2 and thereby inhibits PRC2 function, to dCas9 (EBdCas9) to allow for PRC2 inhibition at a precise locus using gRNA. Targeting EBdCas9 to four different genes (TBX18, p16, CDX2, and GATA3) results in precise H3K27me3 and EZH2 reduction, gene activation, and functional outcomes in the cell cycle (p16) or trophoblast transdifferentiation (CDX2 and GATA3). In the case of TBX18, we identify a PRC2-controlled, functional TATA box >500 bp upstream of the TBX18 transcription start site (TSS) using EBdCas9. Deletion of this TATA box eliminates EBdCas9-dependent TATA binding protein (TBP) recruitment and transcriptional activation. EBdCas9 technology may provide a broadly applicable tool for epigenomic control of gene regulation.

In recent years, to deliver an effective transplantation process and develop better disease models, considerable efforts are devoted to advancing innovative techniques and strategies for tissue regeneration. Nanotechnology has given rise to various molecularly engineered nanostructures (organic and non-organic) and nanoprinting that can be manipulated for therapeutic and diagnostic purposes. Moreover, a whole new class of nanodevices and nano-robots has evolved with three-dimensional (3D), and four-dimensional (4D) nanoprinting frameworks to unlock tremendous potential for tissue engineering. This book chapter highlights an exhaustive overview of 3D, 4D nanoprinting applications over the traditional scaffold production strategy in sustaining tissue viability and advancing functional maturation in building regenerative constructs. Challenges and emerging possibilities for viable nano-bioprinting tissues are also addressed, converging on future research in the field.

The conventional cancer therapies remain inefficacious due to the lack of adequate specificity. Current anti-cancer treatments majorly focus on destroying cancer cells by targeting ROS which is considered as an efficient strategy. Cancer cells have enhanced levels of cellular reactive oxygen species (ROS) than normal cells owing to the variation between oxidants and antioxidants which serves as the basis of accelerating its growth by initiating cancer signaling pathways. These cells preserve the intracellular redox reservoir due to the drastic increase in its antioxidant capacity. This modulation of oxidative stress level is considered a significant treatment option to initiate anti-tumor response. PI3K/Akt pathway is an influential cancer signaling pathway implicated in maintaining intracellular ROS which could be used for targeting ROS-induced carcinomas. Considering an effective way of directing targeted treatments, stem cell-mediated therapy is gaining attention recently. Since stem cells are one of the most reliable therapeutic sources that has several benefits over other treatments, it is of great significance. Myriads of stem cell-based therapeutics have now been validated through preclinical trials and are reported as one of the best methods available. This chapter focuses on the role of the PI3K pathway in stem cell therapeutics in ROS-induced carcinomas.

PURPOSE:During sepsis, an excessive inflammatory immune reaction contributes to multi-organ dysfunction syndrome (MODS), a critical condition associated with high morbidity and mortality; however, the molecular mechanisms driving MODS remain elusive.METHODS:We used RNA sequencing to characterize transcriptional changes in the early phase of sepsis, at 6, 12, 24 hour time points in lung, kidney, liver, and heart tissues, in a cecal ligation and puncture (CLP)-induced polymicrobial sepsis murine model.RESULTS:The CLP surgery induced significant changes (adj. p-value<0.05) in expression of hundreds of transcripts in the four organs tested, with the highest number exceeding 2,000 differentially expressed genes (DEGs) in all organs at 12 hours post-CLP. Over-representation analysis by functional annotations of DEGs to the Reactome database revealed the immune system, hemostasis, lipid metabolism, signal transduction, and extracellular matrix remodeling biological processes as significantly altered in at least two organs, while metabolism of proteins and RNA were revelaed as being liver tissue specific in the early phase of sepsis.CONCLUSION:RNA sequencing across organs and time-points in the CLP murine model allowed us to study the trajectories of transcriptome changes demonstrating alterations common across multiple organs as well as biological pathways altered in an organ-specific manner. These findings could pave new directions in the research of sepsis-induced MODS and indicate new sepsis treatment strategies.