Inhibit Gene Expression Research Articles

Phenamacril and carbendazim regulate trichothecene mycotoxin synthesis by affecting ROS levels in F. asiaticum

Fusarium head blight caused by Fusarium asiaticum is an important cereal crop disease, and the trichothecene mycotoxins produced by F. asiaticum can contaminate wheat grain, which is very harmful to humans and animals. To effectively control FHB in large areas, the application of fungicides is the major strategy; however, the application of different types of fungicides has varying influences on the accumulation of trichothecene mycotoxins in F. asiaticum. In this study, phenamacril inhibited trichothecene mycotoxin accumulation in F. asiaticum; however, carbendazim (N-1H-benzimidazol-2-yl-carbamic acid, methyl ester) induced trichothecene mycotoxin accumulation. Additionally, phenamacril led to a lower level of reactive oxygen species (ROS) by inducing gene expression of the catalase and superoxide dismutase (SOD) pathways in F. asiaticum, whereas carbendazim stimulated ROS accumulation by inhibiting gene expression of the catalase and SOD pathways. Based on these results, we conclude that phenamacril and carbendazim regulate trichothecene mycotoxin synthesis by affecting ROS levels in F. asiaticum.

A Combinatorial Nanobased Spray-Induced Gene Silencing Technique for Crop Protection and Improvement.

Recent research reports have shown that plant pests and pathogens have depleted the crop yield widely, which has led to an increased dependence on commercial pesticides and fungicides. Increased usage of these pesticides has also shown adverse effects on the environment, therefore many techniques have been implemented for solving the issue, some of which include using nanobioconjugates, RNA(i), which put into use double-stranded RNAs to inhibit gene expression. A more innovative and eco-friendly strategy includes spray induced gene silencing, which is being increasingly implemented. This review delves into the eco-friendly approach of spray induced gene silencing (SIGS) in combination with nanobioconjugates, which have been used concerning various plant hosts and their pathogens to provide improved protection. Furthermore, nanotechnological advancements have been understood by addressing the scientific gaps to provide a rationale for the development of updated techniques in crop protection.

Δ8-THC Induces Up-Regulation of Glutamatergic Pathway Genes in Differentiated SH-SY5Y: A Transcriptomic Study.

Cannabinoids, natural or synthetic, have antidepressant, anxiolytic, anticonvulsant, and anti-psychotic properties. Cannabidiol (CBD) and delta-9-tetrahydrocannabinol (Δ9-THC) are the most studied cannabinoids, but recently, attention has turned towards minor cannabinoids. Delta-8-tetrahydrocannabinol (Δ8-THC), an isomer of Δ9-THC, is a compound for which, to date, there is no evidence of its role in the modulation of synaptic pathways. The aim of our work was to evaluate the effects of Δ8-THC on differentiated SH-SY5Y human neuroblastoma cells. Using next generation sequencing (NGS), we investigated whether Δ8-THC could modify the transcriptomic profile of genes involved in synapse functions. Our results showed that Δ8-THC upregulates the expression of genes involved in the glutamatergic pathway and inhibits gene expression at cholinergic synapses. Conversely, Δ8-THC did not modify the transcriptomic profile of genes involved in the GABAergic and dopaminergic pathways.

Fluorescence polarization reveals a possible displacement model of competition in PRC2:RNA:DNA interactions

PRC2 is a histone methyltransferase that acts on histone subunit H3 at lysine 27 to repress chromatin state and inhibit gene expression. The interactions between PRC2 and RNA have been heavily studied in vivo and in vitro with conflicting results reported on the relationship, but there is less data on interactions between PRC2 and DNA. Fluorescence polarization-based methodology was used with various RNA and DNA species to study the binding kinetics of PRC2 with RNA and DNA. Previous data indicate that PRC2 has a relatively high affinity for DNA species that are rich in consecutive G and C nucleotides. Double-stranded DNA species with lengths of 50-60 bp were designed for this project. Fluorescence polarization binding experiments were used to identify the general binding affinity of the DNA and RNA species to PRC2 by calculating the Kd apparent for the binding curve. After the apparent binding affinities were determined, various FP-competition experiments were performed to determine if each DNA species could be competed off by an RNA species or itself, and vice versa. These results showed that the DNA species were more effective competitors although the RNA species were stronger binders. These results suggest a mechanism for RNA-mediated PRC2 regulation that could reconcile the conflicting experimental results and interpretations of past experiments. Further FP-based Kd experiments under varying salt concentrations revealed PRC2 has ionic interactions with DNA that are not seen with RNA. This suggests PRC2 has extra unique interactions with DNA, which could explain the differing effectiveness of DNA versus RNA as competitors. Altogether, the results imply that DNA has additional contacts with PRC2 that limit its displacement by RNA, allowing for RNA to guide PRC2 to its target genetic loci and then for PRC2 to deposit its methyl marks without being sequestered by RNA. Lay Summary PRC2 is a protein involved in gene expression. Its role is to repress chromatin state, inhibiting gene expression during development. This protein is vital to developmentand has been linked to multiple diseases of the body including skin cancer and other forms. When the protein is doing its job correctly, it interacts with DNA in order to repress chromatin. RNA has been shown to be vital in anchoring PRC2 in the correct spot on chromatin, but studies have shown conflicting results in how it interacts with PRC2. In order to study how PRC2 interacts with DNA and RNA, fluorescence polarization-based methodology was used with various RNA and DNA species to study their binding kinetics to PRC2 individually. After the apparent binding affinities were determined, various FP-competition experiments were performed to determine if each DNA species could be competed off by an RNA species or itself, and vice versa. The DNA species were more effective competitors although the RNA species were stronger binders. These results along with other experiments revealed PRC2 has ionic interactions with DNA that are unique to DNA, which explains how the DNA species could compete off RNA. Altogether, the results imply that DNA has additional contacts with PRC2 that limit its displacement by RNA, allowing for RNA to guide PRC2 to its target genetic loci and then for PRC2 to deposit its methyl marks without being sequestered by RNA. To see the complete thesis, please visit https://scholar.colorado.edu/concern/undergraduate_honors_theses/5x21tg835.

H3K9 dimethyltransferase G9a is an important epigenetic modulator of B cell differentiation

Abstract Plasma cell differentiation is a tightly regulated process coordinated by the timed expression of several transcription factors as well as histone modifying enzymes that modulate chromatin accessibility. During this process, the histone methyltransferase (HMT) G9a, dimethylates histone H3 lysine 9 (H3K9) at promoters and inhibits gene expression through the recruitment of proteins that impair chromatin accessibility. HMTs are expressed ubiquitously but display distinct enzymatic activities and patterns of chromosomal localization. During plasma cell differentiation, G9a was found to co-localize with Blimp-1, which is required to silence genes associated with a B cell fate and cellular proliferation. However, the processes that are modulated by G9a mediated dimethylation during plasma cell formation remain to be elucidated. To study the role of G9a in plasma cell differentiation, we crossed G9a fl/flmice onto the CD19 Cre/+background (G9aKO mice). Stimulation of CD19 Cre/+(CreCtrl) and G9aKO mice with the T cell independent antigen LPS resulted in a significant increase of activated B cells and plasmablast in G9aKO mice. Further characterization of this phenotype, identified a skewing of the mature B cell sub-populations in G9aKO mice, accompanied by altered proliferation rates when challenged. ATAC-Seq and RNA-Seq will be used to identify chromatin accessibility and expression changes in G9a deficient mice. The CUT&Tag assay will also be used to validate regions that are subject to direct modulation by G9a during plasma cell differentiation. Together, our data suggests that G9a contributes to regulating proliferation during plasma cell differentiation. his work is supported by grants from NIH/NIAID (RO1 AI123733 and P01 AI125180 to JMB)

Abstract 6102: Targeting BARD1 slows PDAC growth in vitro and in vivo and sensitizes cells to DNA damaging agents

Abstract Pancreatic ductal adenocarcinoma (PDAC) is the most prevalent malignant neoplasm of the pancreas, responsible for over 90% of pancreatic cancer cases. Despite recent therapeutic advances, the five-year overall survival rate for PDAC is only 11% and therapies remain limited. It is now known that deficiency in DNA damage repair (DDR) renders PDAC cells vulnerable to certain DNA damage agents, for example, poly (ADP-ribose) polymerase inhibitors (PARPi). Most of the DDR genes mutated in PDAC are crucial for the proper functioning of the homologous recombination repair (HRR) pathway, and loss-of-function alterations in DDR genes sensitize cells to DNA-damaging agents. Since this treatment strategy is currently limited to 5-10% of PDAC cases with known mutations in the DDR genes, it underscores a dire need to understand new therapeutic avenues and expand the PDAC patient population that could benefit from this therapeutic approach. We have recently published that BARD1 (BRCA1- Associated- Ring- Domain- 1), an obligate binding partner of BRCA1, is upregulated in PDAC cells exposed to PARPi/platinums. We found that transient inhibition of BARD1 rendered PDAC cells extremely sensitive to olaparib (PARPi)/oxaliplatin (platinum), and enhanced DNA damage. Based on these results, we created two genetic models of BARD1 inhibition and utilized these model systems to investigate if loss of BARD1 chemo-sensitizes PDAC cells to other PARPis and DNA damage agents. Doxycycline inducible shRNA and BARD1 CRISPR KO models were created to inhibit gene expression of BARD1 in PDAC cells. We first characterized these model systems to confirm the loss of BARD1 protein and mRNA expression by western blot and qRT-PCR analyses. Using colony formation and Pico green cell survival assays, we found that inhibiting BARD1 resulted in slower growth of pancreatic cancer cells in vitro. Moreover, expression of several cell cycle genes from G2-M phase was significantly decreased (p=0.05). These studies were recapitulated in a mouse xenograft subcutaneous model, where BARD1 KO and WT PDAC cells were injected subcutaneously and tumor growth was analyzed over 25-30 days. Kaplan-Meier curves were calculated and plotted using Log-rank test. We found that inhibiting BARD1 significantly (p=0.026) delayed formation of PDAC tumors in vivo. Next, we analyzed the efficacies of various DNA damaging agents when BARD1 was inhibited. Silencing or CRISPR KO of BARD1 enhanced efficacy of mitomycin C, irinotecan, as well as other PARPis, which are currently in clinical trials (rucaparib, veliparib) in vitro and lowered their IC50s. These results indicate that targeting BARD1 has the potential to benefit patients in terms of novel or improved treatments. Our ongoing and future studies will expand on these findings to understand BARD1-mediated pathway and evaluate sensitivity of multiple DNA damage agents by screening a library of > 250 compounds. Citation Format: Sohum Patel, Anoohya Arkala, Avinoam Nevler, Carolyn Coats, Charles J. Yeo, Aditi Jain. Targeting BARD1 slows PDAC growth in vitro and in vivo and sensitizes cells to DNA damaging agents. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6102.

The applications of CRISPR/Cas9 System for Urinary System Tumor.

Tumors of the urinary system include those in the urinary and reproductive systems, of which tumors of the prostate, bladder, and kidney have the highest incidence. In recent years, due to changes in dietary structure, prostate cancer has become the most common type of male genitourinary system cancer. Furthermore, due to tobacco consumption, increases in industrialization, and the age of the population, the incidence of bladder cancer in both males and females in both urban and rural areas, has shown an increasing trend. The incidence and mortality of kidney cancer have also increased and negatively affected the lives and health of all residents. While surgery, radiotherapy, and chemotherapy have greatly improved the cure and survival rates of patients with urinary tumors, we lack methods for early detection and effective long-term treatment. New tools and methods for diagnosis and treatment are thus urgently needed. Recently, CRISPR/Cas9 has become an efficient method to alter the genome in many organisms. It can be used to activate or inhibit gene expression, which greatly facilitates the editing of targeted genes, both in vivo and in vitro. It provides a powerful scientific research tool to analyze the mechanisms of disease occurrence and development and to develop advanced targeted drug delivery. The diagnosis and treatment of human tumors will consequently be improved as this technology will surely accelerate cancer research. In this article, we discuss how CRISPR/Cas9 technology can be used to research and treat genitourinary system tumors will consequently be improved as this technology will surely accelerate cancer research. Here, we review the current applications of CRISPR/Cas9 technology for genitourinary system tumor research and therapy.

Low-dose ketamine inhibits neuronal apoptosis and neuroinflammation in PC12 cells via α7nAChR mediated TLR4/MAPK/NF-κB signaling pathway.

Ketamine is commonly used for sedation, analgesia and anesthetics. Much evidence has shown that it has an immune-regulatory effect. The cholinergic anti-inflammatory pathway mediated by α7nAChR is a prominent target of anti-inflammatory therapy. However, whether ketamine suppresses inflammatory levels in nerve cells by activating α7nAChR remains unknown. Lipopolysaccharide (LPS) was used to establish the neuroinflammation model in PC12 cells in vitro, and α7nAChR siRNA was transfected into PC12 cells 30min before LPS to inhibit gene expression of α7nAChR. PC12 cells were stimulated with LPS for 24h, and the indicators were detected at 2h after GTS-21 and ketamine were added. The results showed that LPS increased the proportion of PC12 cells apoptosis, activated TLR4/MAPK/NF-κB signaling pathway, and increased the expression of interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). Ketamine reduced the ratio of early apoptosis and late apoptosis of PC12, inhibited the entry of P65 into the nucleus, decreased the activation of TLR4/MAPK/NF-κB and improved neuroinflammation. However, the ameliorating effects of ketamine on neuronal apoptosis and neuroinflammation were inhibited in the α7nAChRi group. This indicated that α7nAChR played a key role in the anti-inflammatory process of ketamine. Low-dose ketamine inhibited TLR4/MAPK/NF-κB by activating the α7nAChR-mediated cholinergic anti-inflammatory pathway, thereby producing the protective effect on neuronal apoptosis and neuroinflammation.

Aquaporin-8 ameliorates hepatic steatosis through farnesoid X receptor in obese mice

Aquaporin-8(AQP8), is a transmembrane channel protein that abounds in liver, which mainly promotes water transport, modulating bile acid formation. However, its role in hepatic lipid metabolism remains unclear. In this study, we found the expression of AQP8 was reduced in liver specimens of patients with NAFLD, high-fat diet (HFD)-induced mice and genetically obese db/db mice. Knockdown of AQP8 in hepatocytes exacerbated the intracellular lipid accumulation induced by free fatty acid (FFA) mixtures. In contrast, hepatic AQP8 overexpression activated farnesoid X receptor (FXR), inhibiting gene expression associated with lipogenesis, which further reduced intrahepatic triglyceride overload in obese mice. FXR knockout abrogated the ameliorating effect of AQP8 overexpression on NAFLD in mice. These findings indicate that AQP8 overexpression protects against fatty liver through activating the FXR pathway.

Advances in natural small molecules on pretranslational regulation of gluconeogenesis.

Different tissues and organs coordinate to keep glucose levels at homeostasis. However, excessive gluconeogenesis in patients with type 2 diabetes mellitus increases blood glucose and causes dysregulation of homeostasis, which easily induces various diseases. Therefore, inhibiting excessive gluconeogenesis is a potential direction to regulate the disorder of blood glucose homeostasis and treat diabetes. The process of gluconeogenesis can be pretranslationally or posttranslationally regulated, and some natural small molecules can be involved in the pretranslational phase of gluconeogenesis, regulating glucose homeostasis by inhibiting gene expression, interfering with RNA transcription, and antagonizing related proteins. This paper will classify and review the natural small molecules with pretranslational regulation of gluconeogenesis according to the action sites and signaling pathways.

Effects of Curcumin on Oxidative Stress and Ferroptosis in Acute Ammonia Stress-Induced Liver Injury in Gibel Carp (Carassius gibelio).

This study investigated the potential role of curcumin (CUR) in preventing oxidative stress and ferroptosis induced by ammonia exposure in gibel carp. Experimental fish (initial weight: 11.22 ± 0.10 g, n = 150) were fed diets supplemented with or without 0.5% CUR for 56 days, followed by a 24 h ammonia (32.5 mg/L) exposure. Liver damages (aspartate aminotransferase (AST), alanine aminotransferase (ALT), adenosine deaminase (ADA), and alkaline phosphatase (ALP)) and oxidative stress enzyme activities (reactive oxygen species (ROS), malondialdehyde (MDA); and the content of antioxidant capacity (T-AOC), superoxide dismutase (SOD), and glutathione peroxidase (GPx)) were induced by ammonia stress. The antioxidant capacity was decreased, as indicated by inhibited gene expression of nuclear factor erythroid 2-related factor 2 (nrf2), heme oxygenase-1 (ho-1), catalase (cat), and sod. Ferroptosis was induced by ammonia stress, as suggested by upregulated mRNA levels of nuclear receptor coactivator 4 (ncoa4), transferrin receptor 1 (tfr1), and iron-responsive element-binding protein 2 (ireb2), and downregulated expression of glutathione peroxidase 4 (gpx4), ferroportin (fpn), and ferritin heavy chain 1 (fth1). In addition, both mRNA and protein levels of ferroptosis markers acyl-CoA synthetase long-chain family member 4 (ACSL4) and prostaglandin-endoperoxide synthase 2 (PTGS2) were upregulated, while cystine/glutamate antiporter (SLC7A11) was downregulated. However, liver injury and ferroptosis in fish induced by ammonia could be attenuated by CUR. Collectively, these findings demonstrate that CUR ameliorates oxidative stress and attenuates ammonia stress-induced ferroptosis. This study provides a new perspective on potential preventive strategies against ammonia stress in gibel carp by dietary CUR.

The E2F4/p130 Repressor Complex Cooperates with Oncogenic ΔNp73α To Inhibit Gene Expression in Human Papillomavirus 38 E6/E7-Transformed Keratinocytes and in Cancer Cells.

Tumor suppressor p53 and its related proteins, p63 and p73, can be synthesized as multiple isoforms lacking part of the N- or C-terminal regions. Specifically, high expression of the ΔNp73α isoform is notoriously associated with various human malignancies characterized by poor prognosis. This isoform is also accumulated by oncogenic viruses, such as Epstein-Barr virus (EBV), as well as genus beta human papillomaviruses (HPV) that appear to be involved in carcinogenesis. To gain additional insight into ΔNp73α mechanisms, we have performed proteomics analyses using human keratinocytes transformed by the E6 and E7 proteins of the beta-HPV type 38 virus as an experimental model (38HK). We find that ΔNp73α associates with the E2F4/p130 repressor complex through a direct interaction with E2F4. This interaction is favored by the N-terminal truncation of p73 characteristic of ΔNp73 isoforms. Moreover, it is independent of the C-terminal splicing status, suggesting that it could represent a general feature of ΔNp73 isoforms (α, β, γ, δ, ε, ζ, θ, η, and η1). We show that the ΔNp73α-E2F4/p130 complex inhibits the expression of specific genes, including genes encoding for negative regulators of proliferation, both in 38HK and in HPV-negative cancer-derived cell lines. Such genes are not inhibited by E2F4/p130 in primary keratinocytes lacking ΔNp73α, indicating that the interaction with ΔNp73α rewires the E2F4 transcriptional program. In conclusion, we have identified and characterized a novel transcriptional regulatory complex with potential implications in oncogenesis. IMPORTANCE The TP53 gene is mutated in about 50% of human cancers. In contrast, the TP63 and TP73 genes are rarely mutated but rather expressed as ΔNp63 and ΔNp73 isoforms in a wide range of malignancies, where they act as p53 antagonists. Accumulation of ΔNp63 and ΔNp73, which is associated with chemoresistance, can result from infection by oncogenic viruses such as EBV or HPV. Our study focuses on the highly carcinogenic ΔNp73α isoform and uses a viral model of cellular transformation. We unveil a physical interaction between ΔNp73α and the E2F4/p130 complex involved in cell cycle control, which rewires the E2F4/p130 transcriptional program. Our work shows that ΔNp73 isoforms can establish interactions with proteins that do not bind to the TAp73α tumor suppressor. This situation is analogous to the gain-of-function interactions of p53 mutants supporting cellular proliferation.

A RNase P Ribozyme Inhibits Gene Expression and Replication of Hepatitis B Virus in Cultured Cells.

Hepatitis B virus (HBV), an international public health concern, is a leading viral cause of liver disease, such as hepatocellular carcinoma. Sequence-specific ribozymes derived from ribonuclease P (RNase P) catalytic RNA are being explored for gene targeting applications. In this study, we engineered an active RNase P ribozyme, M1-S-A, targeting the overlapping region of HBV S mRNA, pre-S/L mRNA, and pregenomic RNA (pgRNA), all deemed essential for viral infection. Ribozyme M1-S-A cleaved the S mRNA sequence efficiently in vitro. We studied the effect of RNase P ribozyme on HBV gene expression and replication using the human hepatocyte HepG2.2.15 culture model that harbors an HBV genome and supports HBV replication. In these cultured cells, the expression of M1-S-A resulted in a reduction of more than 80% in both HBV RNA and protein levels and an inhibition of about 300-fold in the capsid-associated HBV DNA levels when compared to the cells that did not express any ribozymes. In control experiments, cells expressing an inactive control ribozyme displayed little impact on HBV RNA and protein levels, and on capsid-associated viral DNA levels. Our study signifies that RNase P ribozyme can suppress HBV gene expression and replication, implying the promise of RNase P ribozymes for anti-HBV therapy.

New in vitro findings about halogenated boroxine cytotoxicity and deregulation of cell death-related genes in GR-M melanoma cells.

Anti-proliferative effects of halogenated boroxine - K2(B3O3F4OH) (HB) - have been confirmed in multiple cancer cell lines, including melanoma, but the exact mechanism of action is still unknown. This study aimed to determine its cytotoxic effects on human Caucasian melanoma (GR-M) cell growth in vitro as well as on the expression of cell death-related genes BCL-2, BECN1, DRAM1, and SQSTM1. GR-M and peripheral blood mononuclear (PBM) cells were treated with different HB concentrations and their growth inhibition and relative gene expression profiles were determined using the Alamar blue assay and real-time PCR. HB significantly inhibited cell growth of both GR-M and PBM cells but was even more effective in GR-M melanoma cells, as significant inhibition occurred at a lower HB concentration of 0.2 mg/mL. GR-M BCL-2 expression was significantly downregulated (P=0.001) at HB concentration of 0.4 mg/mL, which suggests that HB is a potent tumour growth inhibitor. At the same time, it upregulated BCL-2 expression in normal (PBM) cells, probably by activating protective mechanisms against induced cytotoxicity. In addition, all but the lowest HB concentrations significantly upregulated SQSTM1 (P=0.001) in GR-M cells. Upregulated BECN1 expression suggests early activation of autophagy at the lowest HB concentration in SQSTM1 cells and at all HB concentrations in PBM cells. Our findings clearly show HB-associated cell death and, along with previous cytotoxicity studies, reveal its promising anti-tumour potential.

Assessment of 'Cabernet Sauvignon' Grape Quality Half-Véraison to Maturity for Grapevines Grown in Different Regions.

Grapes are widely cultivated around the world and their quality has distinct regional characteristics. In this study, the qualitative characteristics of the 'Cabernet Sauvignon' grape variety in seven regions, from half-véraison to maturity, were analyzed comprehensively at physiological and transcriptional levels. The results indicated that the quality traits of 'Cabernet Sauvignon' grapes in different regions were significantly different with obvious regionality. Total phenols, anthocyanins, and titratable acids were the main factors of the regionality of berry quality, which were very sensitive to changes in the environment. It should be noted that the changes in titrating acids and total anthocyanin of berries vary greatly from half-véraison to maturity between regions. Moreover, the transcriptional analysis showed that the co-expressed genes between regions characterized the core transcriptome of berry development, while the unique genes of each region reflected the regionality of berries. The differentially expressed genes (DEGs) between half-véraison and maturity can be used to demonstrate that the environment of the regions could promote or inhibit gene expression. The functional enrichment suggested that these DEGs help to understand the interpretation of the plasticity of the quality composition of grapes according to the environment. Taken together, the information generated by this study could contribute to the development of viticultural practices aimed at making better use of native varieties for the development of wines with regional characteristics.

Shade represses photosynthetic genes by disrupting the DNA binding of GOLDEN2-LIKE1.

PHYTOCHROME-INTERACTING FACTORs (PIFs) repress photosynthetic genes partly by upregulating REPRESSOR OF PHOTOSYNTHETIC GENES 1 (RPGE1) and RPGE2. However, it is unknown how RPGEs inhibit gene expression at the molecular level. Here, we show that Arabidopsis (Arabidopsis thaliana) RPGE overexpression lines display extensive similarities to the golden2-like 1 (glk1)/glk2 double mutant at the phenotypic and transcriptomic levels, prompting us to hypothesize that there is a close molecular relationship between RPGEs and chloroplast development-regulating GLK transcription factors. Indeed, we found that RPGE1 disrupts the homodimerization of GLK1 by interacting with its dimerization domain and debilitates the DNA-binding activity of GLK1. The interaction was not restricted to the Arabidopsis RPGE1-GLK1 pair, but rather extended to RPGE-GLK homolog pairs across species, providing a molecular basis for the pale green leaves of Arabidopsis transgenic lines expressing a rice (Oryza sativa) RPGE homolog. Our discovery of RPGE-GLK regulatory pairs suggests that any condition leading to an increase in RPGE levels would decrease the expression levels of GLK target genes. Consistently, we found that shade, which upregulates the RPGE mRNA by stabilizing PIFs, represses the expression of photosynthetic genes partly by inhibiting the DNA-binding activity of GLK1. Taken together, these results indicate that RPGE-GLK regulatory pairs regulate photosynthetic gene expression downstream of PIFs.

The role of tripartite motif-containing 28 in cancer progression and its therapeutic potentials.

Tripartite motif-containing 28 (TRIM28) belongs to tripartite motif (TRIM) family. TRIM28 not only binds and degrades its downstream target, but also acts as a transcription co-factor to inhibit gene expression. More and more studies have shown that TRIM28 plays a vital role in tumor genesis and progression. Here, we reviewed the role of TRIM28 in tumor proliferation, migration, invasion and cell death. Moreover, we also summarized the important role of TRIM28 in tumor stemness sustainability and immune regulation. Because of the importance of TRIM28 in tumors, TIRM28 may be a candidate target for anti-tumor therapy and play an important role in tumor diagnosis and treatment in the future.

PS-B04-8: YM750, AN ACAT1 INHIBITOR, REDUCES ALDOSTERONE SECRETION BY DECREASING ADRENAL CYP11B2 EXPRESSION

Primary aldosteronism (PA) is a refractory hypertension that accounts for approximately 5%-10% of hypertensive patients. aldosterone-producing adenomas and idiopathic hyperaldosteronism are known causes of PA. In aldosterone-producing adenomas, depolarization due to somatic mutations of ion channels in adrenocortical cells is considered the cause of aldosterone oversecretion. Recently, there have been reports on the expression of various cholesterol-metabolizing enzymes in aldosterone-producing adenomas, suggesting that intracellular cholesterol metabolism is very important for aldosterone secretion. We present here the possibility that an inhibitor of Acetyl-CoA acetyltransferase (ACAT1), an enzyme that converts cholesterol to cholesteryl esters, may inhibit aldosterone secretion by depolarization in adrenal cells. Potassium chloride and YM750, an ACAT1 inhibitor, were added to human adrenocortical carcinoma, H295R cells. Then, we measured aldosterone synthase gene, CYP11B2 mRNA expression level. As a result, the expression level of CYP11B2 decreased. Both NURR1 and NGFIB mRNA expression levels also decreased. Additionally, aldosterone production was also measured and found to be significantly decreased in the YM750 added group. Next, angiotensin II was added and the inhibitory effect of YM750 was examined. The results showed that CYP11B2 expression was not decreased. This indicates that YM750 decreased the induction of CYP11B2 expression in a potassium chloride-induced stimulus-specific manner. The experimental results suggest that YM750 specifically inhibits CYP11B2 gene expression by cell depolarization and suppresses aldosterone secretion. However, there are few reports of cholesterol metabolism affecting CYP11B2 gene expression. In this study, we found that intracellular cholesterol metabolism may affect CYP11B2 gene expression. We plan to investigate the relationship between ACAT inhibition and CYP11B2 gene expression in detail mechanisms in the future.

The apple Argonaute gene MdAGO1 modulates salt tolerance

Salinity is a significant environmental challenge that detrimentally affects the yield and quality of plants. The Argonaute (AGO) family proteins are core effectors of RNAi pathways in eukaryotes. Different AGOs bind different types of sRNAs and participate in different silencing pathways and physiological processes. The Argonaute1 (AGO1) protein binds microRNAs and post-transcriptionally inhibits gene expression in the cytoplasm. In addition, AGO1 directly binds to the promoter region of genes to promote transcription in the stress responses. In this study, we isolated the AGO family gene MdAGO1 from apple (Malus domestica). MdAGO1 encodes a protein located in the nucleus and cytoplasm. MdAGO1 expression was significantly induced by salt stress. We employed MdAGO1-RNAi transgenic apple plants, MdAGO1 overexpressing transgenic apple calli, and Arabidopsis thaliana to investigate the role of MdAGO1 in salt stress. We exposed all of the genotypes to salt stress and showed that MdAGO1 played a role in scavenging reactive oxygen species, maintaining ion balance, and increasing the accumulation of polyamines in the plants under salt stress. In addition, the MdAGO1-RNAi apple lines exhibited low photosynthetic capacity under salt stress. Taken together, these results reveal that MdAGO1 positively regulates apple salt tolerance.

Triplex-forming oligonucleotides as an anti-gene technique for cancer therapy.

Triplex-forming oligonucleotides (TFOs) can bind to the major groove of double-stranded DNA with high specificity and affinity and inhibit gene expression. Triplex-forming oligonucleotides have gained prominence because of their potential applications in antigene therapy. In particular, the target specificity of triplex-forming oligonucleotides combined with their ability to suppress oncogene expression has driven their development as anti-cancer agents. So far, triplex-forming oligonucleotides have not been used for clinical treatment and seem to be gradually snubbed in recent years. But triplex-forming oligonucleotides still represent an approach to down-regulate the expression of the target gene and a carrier of active substances. Therefore, in the present review, we will introduce the characteristics of triplex-forming oligonucleotides and their anti-cancer research progress. Then, we will discuss the challenges in their application.