Prenatal Octamethylcyclotetrasiloxane Exposure Impaired Proliferation of Neuronal Progenitor, Leading to Motor, Cognition, Social and Behavioral Functions

Cyclic siloxane octamethylcyclotetrasiloxane (D4) has raised concerns as an endocrine-disrupting chemical (EDC). D4 is widely used in detergent products, cosmetics, and personal care products. Recently, robust toxicological data for D4 has been reported, but the adverse effects of D4 on brain development are unknown. Here, pregnant mice on gestational day 9.5 were treated daily with D4 to postnatal day 28, and the offspring mice were studied. The prenatal D4-treated mice exhibited cognitive dysfunction, limited memory, and motor learning defect. Moreover, prenatal D4 exposure reduced the proliferation of neuronal progenitors in the offspring mouse brain. Next, the mechanisms through which D4 regulated the cell cycle were investigated. Aberrant gene expression, such as cyclin-dependent kinases CDK6 and cyclin-dependent kinase inhibitor p27, were found in the prenatal D4-treated mice. Furthermore, the estrogen receptors ERa and ERb were increased in the brain of prenatal D4-treated mice. Overall, these findings suggest that D4 exerts estrogen activity that affects the cell cycle progression of neuronal progenitor cells during neurodevelopment, which may be associated with cognitive deficits in offspring.

Dysregulation of alternative splicing is associated with the pathogenesis of ulcerative colitis

Background Although numerous risk loci for ulcerative colitis (UC) have been identified in the human genome, the pathogenesis of UC remains unclear. Recently, multiple transcriptomic analyses have shown that aberrant gene expression in the colon tissues of UC patients is associated with disease progression. A pioneering study also demonstrated that altered post-transcriptional regulation is involved in the progression of UC. Here, we provide a genome-wide analysis of alternative splicing (AS) signatures in UC patients. We analyzed three datasets containing 74 tissue samples from UC patients and identified over 2000 significant AS events. Results Skipped exon and alternative first exon were the two most significantly altered AS events in UC patients. The immune response-related pathways were remarkably enriched in the UC-related AS events. Genes with significant AS events were more likely to be dysregulated at the expression level. Conclusions We present a genomic landscape of AS events in UC patients based on a combined analysis of two cohorts. Our results indicate that dysregulation of AS may have a pivotal role in determining the pathogenesis of UC. In addition, our study uncovers genes with potential therapeutic implications for UC treatment.

Role of Flavonoids as Epigenetic Modulators in Cancer Prevention and Therapy

Epigenetic regulation involves reversible changes in histones and DNA modifications that can be inherited without any changes in the DNA sequence. Dysregulation of normal epigenetic processes can lead to aberrant gene expression as observed in many diseases, notably cancer. Recent insights into the mechanisms of DNA methylation, histone modifications, and non-coding RNAs involved in altered gene expression profiles of tumor cells have caused a paradigm shift in the diagnostic and therapeutic approaches towards cancer. There has been a surge in search for compounds that could modulate the altered epigenetic landscape of tumor cells, and to exploit their therapeutic potential against cancers. Flavonoids are naturally occurring phenol compounds which are abundantly found among phytochemicals and have potentials to modulate epigenetic processes. Knowledge of the precise flavonoid-mediated epigenetic alterations is needed for the development of epigenetics drugs and combinatorial therapeutic approaches against cancers. This review is aimed to comprehensively explore the epigenetic modulations of flavonoids and their anti-tumor activities.

An alternative splicing signature in human Crohn’s disease

Background Although hundreds of risk loci for Crohn’s disease (CD) have been identified, the underlying pathogenesis of CD remains unclear. Recently, evidence has shown that aberrant gene expression in colon tissues of CD patients is associated with the progression of CD. We reasoned that post-transcriptional regulation, especially alternative splicing (AS), may also play important roles in the pathogenesis of CD. Methods We re-analyzed public mRNA-seq data from the NCBI GEO dataset (GSE66207) and identified approximately 3000 unique AS events in CD patients compared to healthy controls. Results “Lysine degradation” and “Sphingolipid metabolism” were the two most enriched AS events in CD patients. In a validation study, we also sequenced eight subjects and demonstrated that key genes that were previously linked to CD, such as IRF1 and STAT3, also had significant AS events in CD. Conclusion Our study provided a landscape of AS events in CD, especially as the first study focused on a Chinese cohort. Our data suggest that dysregulation of AS may be a new mechanism that contributes to the pathogenesis of CD.

A feedback loop between heterochromatin and the nucleopore complex controls germ-cell to oocyte transition during Drosophila oogenesis

Germ cells differentiate into oocytes that become totipotent upon fertilization. How the highly specialized oocyte acquires this distinct cell fate is poorly understood. During Drosophila oogenesis, H3K9me3 histone methyltransferase SETDB1 translocates from the cytoplasm to the nucleus of germ cells concurrent with oocyte specification. Here, we discovered that nuclear SETDB1 is required to silence a cohort of differentiation-promoting genes by mediating their heterochromatinization. Intriguingly, SETDB1 is also required for the upregulation of 18 of the ~30 nucleoporins (Nups) that comprise the nucleopore complex (NPC). NPCs in turn anchor SETDB1-dependent heterochromatin at the nuclear periphery to maintain H3K9me3 and gene silencing in the egg chambers. Aberrant gene expression due to loss of SETDB1 or Nups results in loss of oocyte identity, cell death and sterility. Thus, a feedback loop between heterochromatin and NPCs promotes transcriptional reprogramming at the onset of oocyte specification that is critical to establish oocyte identity.

78 Novel RNA-seq platform improve patient outcome in clinical oncology and enable implementation of AI in the clinic

BackgroundOnly 1 out of 4 cancer treatments prolongs life while expenditure for cancer treatment is greater than $100 billion/year. RNA-sequencing has allowed researchers to gain insight into the transcriptome of human cancers. However, RNA-sequencing remains widely unused in clinical oncology. We address this issue through the development and CLIA validation of OneRNA—an RNA-sequencing platform for cancer diagnostics and the design of new treatments. The development of OneRNA had to overcome the two main hurdles for implementation of RNA sequencing in the clinic: 1) clinical samples are typically embedded in FFPE which results in highly fragmented RNA making sequencing of these samples difficult. 2) how to interpret aberrant gene expression events and translate these results into clinical action. We demonstrate how OneRNA® would enable the design of sophisticated combinatorial clinical studies. An example is combining immune targeting agents such as checkpoint inhibitors with mRNA vaccines. OneRNA also supports the integration of gene expression algorithms because of its ability to interrogate the entire sample transcriptome. OneRNA® has been CLIA certified using FFPE, FF, blood, and saliva samples. Furthermore, the sample preparation method has demonstrated >95% concordance between FF and FFPE and 5–10X the sensitivity compared to Truseq.MethodsThis study aims to demonstrate the clinical utility of OneRNA in detecting aberrant gene expression events and connecting these to already approved drugs that targets these events to offer truly individualized treatment options.ResultsWe show that OneRNA has the ability to predict results for not only validated biomarkers used in standard of care such as ER, PR and HER2 in breast cancer, but also provide insight into biomarkers for response to already approved drugs independent of tissue type and with no standard test. Finally, we demonstrate the reproducibility of OneRNA in predicting IHC status in ER, PR and HER2.ConclusionsThese results demonstrate that OneRNA has applications in both cancer research, drug discovery and development, development of companion diagnostic algorithms and implementation of truly individualized treatment.

mRNA Transcriptomic Profiling of Human Hepatocellular Carcinoma Cells HepG2 Treated with Catharanthus roseus-Silver Nanoparticles

Background: The demand in the development of cancer nanomedicine has increased due to various limitations in conventional cancer therapy. This study assessed the mRNA transcriptomic profiling of human HepG2 cells exposed to C. roseus-AgNPs. Methods: The proliferative activity of hepatocellular carcinoma (HepG2) and normal human liver (THLE3) cells treated with C. roseus‑AgNPs were measured using MTT assay. The RNA samples were extracted and sequenced using BGIseq500 platform. This is followed by data filtering, mapping, gene expression analysis, DEG analysis, GO analysis, and pathway analysis. Results: The mean IC50 values of C. roseus‑AgNPs on HepG2 was 4.38±1.59 µg/mL while on THLE3 cells was 800±1.55 µg/mL. Transciptomic profiling revealed an alteration of 296 genes. C. roseus‑AgNPs induced the expression of stress-associated genes such as MT, HSP and HMOX-1. Cellular signaling pathways were potentially activated through MAPK, TNF and TGF pathways that responsible for apoptosis and cell cycle arrest. The alteration of ARF6, EHD2, FGFR3, RhoA, EEA1, VPS28, VPS25, TSG101 indicated the uptake of C. roseus-AgNPs via both clathrin-dependent and clathrin-independent endocytosis. Conclusions: This study provides the new insights on gene expression study of biosynthesized AgNPs on cancer cells. The cytotoxicity effect is mediated by the aberrant gene alteration, and more interestingly the unique selective antiproliferative properties indicates the C. roseus‑AgNPs as an ideal anticancer candidate.

Dysregulation of Alternative Splicing was Associated with the Pathogenesis of Ulcerative Colitis

Background: Although numerous risk loci of Ulcerative Colitis (UC) in the human genome have been identified, the pathogenesis of UC remains not fully understood. Recently, multiple transcriptomic analyses have shown that aberrant gene expression in UC patients’ colon tissues were associated with the disease progressing. A pioneer study also demonstrated that altered post-transcriptional regulation may be involved in the progression of UC. Methods: Herein, we provided a comprehensive analysis of alternative splicing (AS) signature on UC patients. We analyzed three datasets, which include 74 tissue samples from UC patients in total, and identified over 2,000 significant AS events in these datasets. Results: Skipped Exon (SE) and Alternative first exon (AFE) were found to be the top two significantly altered AS events. Immune response related pathways were significantly enriched. Genes that showed significantly AS events were more likely to be dysregulated at the expression level.Conclusion: Overall, these results suggested that alteration of AS may play crucial roles in the pathogenesis of UC.

HBO1-MLL interaction promotes AF4/ENL/P-TEFb-mediated leukemogenesis

Leukemic oncoproteins cause uncontrolled self-renewal of hematopoietic progenitors by aberrant gene activation, eventually causing leukemia. However, the molecular mechanism underlying aberrant gene activation remains elusive. Here, we showed that leukemic MLL fusion proteins associate with the HBO1 histone acetyltransferase (HAT) complex through their trithorax homology domain 2 (THD2) in various human cell lines. MLL proteins associated with the HBO1 complex through multiple contacts mediated mainly by the ING4/5 and PHF16 subunits in a chromatin-bound context where histone H3 lysine 4 tri-methylation marks were present. Of the many MLL fusions, MLL-ELL particularly depended on the THD2-mediated association with the HBO1 complex for leukemic transformation. The C-terminal portion of ELL provided a binding platform for multiple factors including AF4, EAF1, and p53. MLL-ELL activated gene expression in murine hematopoietic progenitors by loading an AF4/ENL/P-TEFb (AEP) complex onto the target promoters wherein the HBO1 complex promoted the association with AEP complex over EAF1 and p53. Moreover, the NUP98-HBO1 fusion protein exerted its oncogenic properties via interaction with MLL but not its intrinsic HAT activity. Thus, the interaction between the HBO1 complex and MLL is an important nexus in leukemic transformation, which may serve as a therapeutic target for drug development.