Galectin-7 Induction by EHMT2 Inhibition Enhances Immunity in Microsatellite Stability Colorectal Cancer.

BACKGROUND & AIMS: Although immunotherapy shows substantial advancement in colorectal cancer (CRC) with microsatellite instability high, it has limited efficacy for CRC with microsatellite stability (MSS). Identifying combinations that reverse immune suppression and prime MSS tumors for current immunotherapy approaches remains an urgent need. METHODS: An in vitro CRISPR screen was performed using coculture models of primary tumor cells and autologous immune cells from MSS CRC patients to identify epigenetic targets that could enhance immunotherapy efficacy in MSS tumors. RESULTS: We revealed EHMT2, a histone methyltransferase, as a potential target for MSS CRC. EHMT2 inhibition transformed the immunosuppressive microenvironment of MSS tumors into an immunomodulatory one by altering cytokine expression, leading to T-cell-mediated cytotoxicity activation and improved responsiveness to anti-PD1 treatment. We observed galectin-7 up-regulation upon EHMT2 inhibition, which converted a "cold" MSS tumor environment into a T-cell-inflamed one. Mechanistically, CHD4 repressed galectin-7 expression by recruiting EHMT2 to form a cotranscriptional silencing complex. Galectin-7 administration enhanced anti-PD1 efficacy in MSS CRC, serving as a potent adjunct cytokine therapy. CONCLUSIONS: Our findings suggest that targeting the EHMT2/galectin-7 axis could provide a novel combination strategy for immunotherapy in MSS CRC.

RNA m6 A methylation regulates sorafenib resistance in liver cancer through FOXO3-mediated autophagy.

N6-methyladenosine (m6 A) is an abundant nucleotide modification in mRNA, known to regulate mRNA stability, splicing, and translation, but it is unclear whether it is also has a physiological role in the intratumoral microenvironment and cancer drug resistance. Here, we find that METTL3, a primary m6 A methyltransferase, is significantly down-regulated in human sorafenib-resistant hepatocellular carcinoma (HCC). Depletion of METTL3 under hypoxia promotes sorafenib resistance and expression of angiogenesis genes in cultured HCC cells and activates autophagy-associated pathways. Mechanistically, we have identified FOXO3 as a key downstream target of METTL3, with m6 A modification of the FOXO3 mRNA 3'-untranslated region increasing its stability through a YTHDF1-dependent mechanism. Analysis of clinical samples furthermore showed that METTL3 and FOXO3 levels are tightly correlated in HCC patients. In mouse xenograft models, METTL3 depletion significantly enhances sorafenib resistance of HCC by abolishing the identified METTL3-mediated FOXO3 mRNA stabilization, and overexpression of FOXO3 restores m6 A-dependent sorafenib sensitivity. Collectively, our work reveals a critical function for METTL3-mediated m6 A modification in the hypoxic tumor microenvironment and identifies FOXO3 as an important target of m6 A modification in the resistance of HCC to sorafenib therapy.

N6-methyladenosine demethylase FTO enhances chemo-resistance in colorectal cancer through SIVA1-mediated apoptosis.

N6-methyladenosine (m6A) is the most pervasive RNA modification and is recognized as a novel epigenetic regulation in RNA metabolism. Although the m6A modification involves various physiological processes, its roles in drug resistance in colorectal cancer (CRC) still remain unknown. We analyzed the RNA expression profile of m6A/A (%) with MRM mass spectrometry in human 5-fluorouracil (5-FU)-resistant CRC tissues, and used the m6A RNA immunoprecipitation assay to validate the m6A-regulated target. Our results have shown that the m6A demethylase FTO was up-regulated in human primary and 5-FU-resistant CRC. Depletion of FTO decreased cell growth, colony formation and metastasis in 5-FU-resistant CRC cells in vitro and in vivo. Mechanistically, we identified SIVA1, a critical apoptotic gene, as a key downstream target of the FTO-mediated m6A demethylation. The m6A demethylation of SIVA1 at the CDS region induced its mRNA degradation via a YTHDF2-dependent mechanism. The SIVA1 levels were negatively correlated with the FTO levels in clinical CRC tissues. Notably, inhibition of FTO significantly reduced the tolerance of 5-FU in 5-FU-resistant CRC cells via the FTO-SIVA1 axis, whereas SIVA1-depletion could restore the m6A-dependent 5-FU sensitivity in CRC cells. In summary, our findings demonstrate a critical role of FTO as an m6A demethylase enhancing chemo-resistance in CRC cells, and suggest that FTO inhibition may restore the sensitivity of chemo-resistant CRC cells to 5-FU.

11-Ethoxyviburtinal improves chronic restraint stress-induced anxiety-like behaviors in gender-specific mice via PI3K/Akt and E2 /ERß signaling pathways.

Anxiety disorder is a chronic and disabling psychiatric disorder that is more prevalent in females than in males. 11-Ethoxyviburtinal is an iridoid extracted from Valeriana jatamansi Jones, which has anxiolytic potential. The aim of the present work was to study the anxiolytic efficacy and mechanism of 11-ethoxyviburtinal in gender-specific mice. We first evaluated the anxiolytic-like efficacy of 11-ethoxyviburtinal in chronic restraint stress (CRS) mice of different sexes through behavioral experiments and biochemical indexes. In addition, network pharmacology and molecular docking were used to predict potential targets and important pathways for the treatment of anxiety disorder with 11-ethoxyviburtinal. Finally, the influence of 11-ethoxyviburtinal on phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt) signaling pathway, estrogen receptor ß (ERß) expression, and anxiety-like behavior in mice was verified by western blotting, immunohistochemistry staining, antagonist intervention methods, and behavioral experiments. 11-ethoxyviburtinal alleviated the anxiety-like behaviors induced by CRS and inhibited neurotransmitter dysregulation and HPA axis hyperactivity. It inhibited the abnormal activation of the PI3K/Akt signaling pathway, modulated estrogen production, and promoted ERß expression in mice. In addition, the female mice may be more sensitive to the pharmacological effects of 11-ethoxyviburtinal. 11-ethoxyviburtinal may exert its anxiolytic-like effects through PI3K/Akt and E2/ERß signaling pathways. Meanwhile, by comparing the male and female mice, gender differences may affect the therapy and development of anxiety disorder.

Selenium Nanoparticles Based on Morinda officinalis Polysaccharides: Characterization, Anti-Cancer Activities, and Immune-Enhancing Activities Evaluation In Vitro.

Recently, selenium nanoparticles have been drawing attention worldwide, and it is crucial to increase the stability of nano-Se. Morinda officinalis polysaccharides (MOP) are the main active component in Morinda officinalis radix. However, their low activity has limited their application. A novel selenium nanoparticle (Se-MOP) was prepared to solve these problems using MOP as a dispersant. The zeta potential was measured to evaluate the stability, and UV and ATR-FTIR were used to investigate the binding type of selenium and MOP. The morphology was observed by the TEM method. Furthermore, the inhibitory effect on five selected cancer cells (HepG2, MCF-7, AGS, PC9, and HCT8) was evaluated, showing remarkable inhibition of all five cancer cells. The mechanism of inhibition was also investigated by cell circle assay, and it was found that Se-MOP could induce cell circle G0/G1 phase arrest. Immune-enhancing activities were evaluated by measuring the proliferation and cytokines of mouse spleen lymphocytes in vitro and quantitative RT-PCR. The results indicated that single stimulation of Se-MOP and synergistic stimulation with PHA or LPS increased immune capacity and improved immune by increasing the expression of cytokines.

Nardostachys jatamansi and levodopa combination alleviates Parkinson's disease symptoms in rats through activation of Nrf2 and inhibition of NLRP3 signaling pathways.

CONTEXT: Levodopa combined with traditional Chinese medicine has a synergistic effect on Parkinson's disease (PD). Recently, we demonstrated that Nardostachys jatamansi (D. Don) DC. [syn. Patrinia jatamansi D.Don, N. grandiflora DC.] (Valerianaceae) (NJ) can alleviate PD. OBJECTIVE: To explore the synergistic effect of NJ combined with levodopa against PD. MATERIALS AND METHODS: The PD model was established by injecting rotenone. Eighty-four Sprague-Dawley rats were randomly divided into seven groups: sham, model, different doses of NJ (0.31, 0.62, or 1.24 g/kg) combined with levodopa (25 mg/kg), and levodopa alone (25 and 50 mg/kg) groups. The synergistic effect of the combination was investigated by pharmacodynamic investigation and detection of expression of nuclear factor erythro2-related factor 2 (Nrf2) and NLR family proteins containing Pyrin-related domain 3 (NLRP3) pathways. RESULTS: Compared with the model group, NJ + levodopa (1.24 g/kg + 25 mg/kg) increased the moving distance of PD rats in the open field (2395.34 ± 668.73 vs. 1501.41 ± 870.23, p < 0.01), enhanced the stay time on the rotating rod (84.86 ± 18.15 vs. 71.36 ± 17.53, p < 0.01) and the combination was superior to other treatments. The synergistic effects were related to NJ + levodopa (1.24 g/kg + 25 mg/kg) increasing the neurotransmitter levels by 38.80%-88.67% in PD rats, and inhibiting oxidative stress and NLRP3 pathway by activating Nrf2 pathway. DISCUSSION AND CONCLUSIONS: NJ combined with levodopa is a promising therapeutic candidate for PD, which provides a scientific basis for the subsequent clinical combination therapy of levodopa to enhance the anti-PD effect.

Loss-of-Function Genetic Screening Identifies Aldolase A as an Essential Driver for Liver Cancer Cell Growth Under Hypoxia.

BACKGROUND AND AIMS: Hypoxia is a common feature of the tumor microenvironment (TME), which promotes tumor progression, metastasis, and therapeutic drug resistance through a myriad of cell activities in tumor and stroma cells. While targeting hypoxic TME is emerging as a promising strategy for treating solid tumors, preclinical development of this approach is lacking in the study of HCC. APPROACH AND RESULTS: From a genome-wide CRISPR/CRISPR-associated 9 gene knockout screening, we identified aldolase A (ALDOA), a key enzyme in glycolysis and gluconeogenesis, as an essential driver for HCC cell growth under hypoxia. Knockdown of ALDOA in HCC cells leads to lactate depletion and consequently inhibits tumor growth. Supplementation with lactate partly rescues the inhibitory effects mediated by ALDOA knockdown. Upon hypoxia, ALDOA is induced by hypoxia-inducible factor-1α and fat mass and obesity-associated protein-mediated N6 -methyladenosine modification through transcriptional and posttranscriptional regulation, respectively. Analysis of The Cancer Genome Atlas shows that elevated levels of ALDOA are significantly correlated with poor prognosis of patients with HCC. In a screen of Food and Drug Administration-approved drugs based on structured hierarchical virtual platforms, we identified the sulfamonomethoxine derivative compound 5 (cpd-5) as a potential inhibitor to target ALDOA, evidenced by the antitumor activity of cpd-5 in preclinical patient-derived xenograft models of HCC. CONCLUSIONS: Our work identifies ALDOA as an essential driver for HCC cell growth under hypoxia, and we demonstrate that inhibition of ALDOA in the hypoxic TME is a promising therapeutic strategy for treating HCC.

Nootkatone alleviates rotenone-induced Parkinson's disease symptoms through activation of the PI3K/Akt signaling pathway.

Parkinson's disease (PD) is the second most common neurodegenerative disease worldwide. Nootkatone (NKT) has been shown to have neuroprotective, anti-inflammatory, and antioxidant effects and in this study, we systematically studied the efficacy and mechanism of action of NKT in rotenone (ROT)-induced PD rats. Firstly, through behavioral experiments and brain tissue staining, we found that NKT alleviated behavioral dysfunction and protected dopaminergic neurons associated with ROT-induced PD rats. Next, target prediction, protein-protein interaction (PPI), Gene Ontology (GO), and pathway enrichment analyses were used to obtain potential targets, specific biological processes, and molecular mechanisms of NKT for the potential treatment of PD. Furthermore, we also applied molecular docking to predict the binding capacity of NKT and related targets. Additionally, in vivo experiments confirmed that NKT could inhibit the expression of Mitogen-activated protein kinase 3 (MAPK3) by activating the PI3K/Akt signaling pathway, reducing neuroinflammation, and ultimately ameliorating ROT-induced PD symptoms. Taken together, the results of the study provide a clear explanation for the remission of PD symptoms by NKT, suggesting that it may be a promising candidate for the treatment of PD.

[Effects of Nardostachys jatamansi on gut microbiota of rats with Parkinson's disease].

Under the guidance of the traditional Chinese medicine(TCM) theory of "Zangfu-organs of spleen and stomach" and the modern theory of "microbiota-gut-brain axis", this study explored the effects of Nardostachys jatamansi on the gut microbiota of rats with Parkinson's disease(PD). The 40 SD rats were randomly divided into the control group, PD model group, levodopa group, and Nardostachys jatamansi ethanol extract group. The PD model was established by subcutaneous injection of rotenone in the neck and back area. After 14 days of intragastric administration, the PD rats' behaviors were analyzed through open field test, inclined plane test, and pole test. After the behavioral tests, the striatum, colon, and colon contents of rats in each group were collected. Western blot was employed to detect the protein expression of tyrosine hydroxylase(TH) and α-synuclein(α-syn) in striatum and that of α-syn in colon. Enzyme linked immunosorbent assay(ELISA) was used to detect the levels of tumor necrosis factor-α(TNF-α), interleukin-1ß(IL-1ß), and nuclear factor-kappa B(NF-κB) in striatum and colon. High-throughput sequencing of 16 S rRNA gene was conducted to detect the differences in microbial diversity, abundance, differential phyla, and dominant bacteria of rats between groups. The results indicated that Nar. ethanol extract could relieve dyskinesia, reverse the increased levels of α-syn, TNF-α, IL-1ß, and NF-κB in striatum, and improve the protein expression of TH in striatum of PD rats. The α diversity analysis indicated a significant decrease in diversity and abundance of gut microbiota in the PD model. The results of linear discriminant analysis effect size(LEfSe) of dominant bacteria indicated that Nardostachys jatamansi ethanol extract increased the relative abundance of Clotridiaceae, Lachnospiraceae, and Anaerostipes, and reversed the increased relative abundance of Proteobacteria, Gammaproteobacteria, Enterobacteriaceae, and Escherichia-Shigella in PD model group to exhibit the neuroprotective effect. In summary, the results indicated that Nar. ethanol extract exert the therapeutic effect on PD rats. Specifically, the extract may regulate gut microbiota, decrease the levels of proinflammatory cytokines, and reduce the protein aggregation of α-syn in the colon and striatum to alleviate intestinal inflammation and neuroinflammation. This study provides a basis for combining the theory of "Zangfu-organs of spleen and stomach" with the theory of "microbiota-gut-brain axis" to treat PD.

RNA-binding protein RALY reprogrammes mitochondrial metabolism via mediating miRNA processing in colorectal cancer.

OBJECTIVE: Dysregulated cellular metabolism is a distinct hallmark of human colorectal cancer (CRC). However, metabolic programme rewiring during tumour progression has yet to be fully understood. DESIGN: We analysed altered gene signatures during colorectal tumour progression, and used a complex of molecular and metabolic assays to study the regulation of metabolism in CRC cell lines, human patient-derived xenograft mouse models and tumour organoid models. RESULTS: We identified a novel RNA-binding protein, RALY (also known as hnRNPCL2), that is highly associated with colorectal tumour aggressiveness. RALY acts as a key regulatory component in the Drosha complex, and promotes the post-transcriptional processing of a specific subset of miRNAs (miR-483, miR-676 and miR-877). These miRNAs systematically downregulate the expression of the metabolism-associated genes (ATP5I, ATP5G1, ATP5G3 and CYC1) and thereby reprogramme mitochondrial metabolism in the cancer cell. Analysis of The Cancer Genome Atlas (TCGA) reveals that increased levels of RALY are associated with poor prognosis in the patients with CRC expressing low levels of mitochondrion-associated genes. Mechanistically, induced processing of these miRNAs is facilitated by their N6-methyladenosine switch under reactive oxygen species (ROS) stress. Inhibition of the m6A methylation abolishes the RALY recognition of the terminal loop of the pri-miRNAs. Knockdown of RALY inhibits colorectal tumour growth and progression in vivo and in organoid models. CONCLUSIONS: Collectively, our results reveal a critical metabolism-centric role of RALY in tumour progression, which may lead to cancer therapeutics targeting RALY for treating CRC.

TP53 loss creates therapeutic vulnerability in colorectal cancer.

TP53, a well-known tumour suppressor gene that encodes p53, is frequently inactivated by mutation or deletion in most human tumours. A tremendous effort has been made to restore p53 activity in cancer therapies. However, no effective p53-based therapy has been successfully translated into clinical cancer treatment owing to the complexity of p53 signalling. Here we demonstrate that genomic deletion of TP53 frequently encompasses essential neighbouring genes, rendering cancer cells with hemizygous TP53 deletion vulnerable to further suppression of such genes. POLR2A is identified as such a gene that is almost always co-deleted with TP53 in human cancers. It encodes the largest and catalytic subunit of the RNA polymerase II complex, which is specifically inhibited by α-amanitin. Our analysis of The Cancer Genome Atlas (TCGA) and Cancer Cell Line Encyclopedia (CCLE) databases reveals that POLR2A expression levels are tightly correlated with its gene copy numbers in human colorectal cancer. Suppression of POLR2A with α-amanitin or small interfering RNAs selectively inhibits the proliferation, survival and tumorigenic potential of colorectal cancer cells with hemizygous TP53 loss in a p53-independent manner. Previous clinical applications of α-amanitin have been limited owing to its liver toxicity. However, we found that α-amanitin-based antibody-drug conjugates are highly effective therapeutic agents with reduced toxicity. Here we show that low doses of α-amanitin-conjugated anti-epithelial cell adhesion molecule (EpCAM) antibody lead to complete tumour regression in mouse models of human colorectal cancer with hemizygous deletion of POLR2A. We anticipate that inhibiting POLR2A will be a new therapeutic approach for human cancers containing such common genomic alterations.

[Study on mechanism of Valerianae Jatamansi Rhizoma et Radix against post-traumatic stress disorder based on molecular docking and network pharmacology].

This paper aims to investigate the active components and mechanism of Valerianae Jatamansi Rhizoma et Radix against post-traumatic stress disorder(PTSD) based on network pharmacology and molecular docking. The main components and targets of Valerianae Jatamansi Rhizoma et Radix were obtained by literature mining methods, SwissTargetPrediction, BATMAN and ETCM database. PTSD-related genes were collected from DrugBank, TTD and CTD databases. The protein-protein interaction(PPI) network was constructed based on STRING, and the core targets of Valerianae Jatamansi Rhizoma et Radix in the treatment of PTSD were selected according to the topological parameters. Cytoscape 3.7.2 was used to construct the compound-target network. DAVID database was used for GO enrichment analysis and KEGG enrichment analysis. The relationship network of "compound-target-pathway" was constructed through Cytoscape 3.7.2 to analyze and obtain the key targets and their corresponding components in the network, and their results were verified by molecular docking. The results showed that a total of 47 components(such as valeraldehyde, dihydrovalerin, valerate, chlorovaltrate K, 8-hydroxypinoresinol, 6-hydroxyluteolin, apigenin, farnesin, vanillin, luteolin, kaempferol, glycosmisic acid and pogostemon) of Valerianae Jatamansi Rhizoma et Radix may act on 94 key targets such as CNR1, MAOA, NR3 C1, MAPK14, MAPK8, HTR2 C and DRD2. Totally 29 GO terms were obtained by GO functional enrichment analysis(P<0.05), and 20 signaling pathways were obtained from KEGG pathway enrichment, mainly involving neuroactive ligand-receptor interaction, serotonergic synapse, calcium signaling pathway, cAMP signaling pathway, dopaminergic synapse, retrograde endocannabinoid signaling, neurotrophin signaling pathway, gap junction, cholinergic synapse, estrogen signaling pathway, glutamatergic synapse and long-term potentiation. Molecular docking analysis showed that hydrogen bonding, π-π interaction and hydrophobic effecting may be the main forms of interaction. This study used the network of compound-target-pathway and molecular docking technology to screen the effective components of Valerianae Jatamansi Rhizoma et Radix against PTSD, and explore its anti-PTSD mechanism, so as to provide scientific basis for exploring the anti-PTSD drugs from traditional Chinese medicine and clarifying its mechanism of action.

[Spectrum-effect relationship of hemostatic effects of Notoginseng Radix et Rhizoma with different commodity specifications].

This article aims to establish the fingerprints, determine the hemostatic pharmacodynamic indicators, and explore the spectrum-effect relationship of Notoginseng Radix et Rhizoma in 12 different specifications. Firstly, HPLC and liquid chromatography-mass spectrometry(LC-MS) were employed to establish the fingerprints of Notoginseng Radix et Rhizoma. The rat plasma recalcification experiment and the rat gastric bleeding experiment were conducted to determine the pharmacodynamic indicators, including plasma recalcification time(PRT), thrombin time(TT), prothrombin time(PT), and activated partial thromboplastin time(APTT). Afterwards, the partial least squares method was employed to explore the spectrum-effect relationship of Notoginseng Radix et Rhizoma in different specifications. Twenty-six common peaks were detected in the HPLC fingerprints of different specifications of Notoginseng Radix et Rhizoma, and 11 out of the 26 common peaks represented saponins. The content of dencichine was determined by LC-MS. The rat experiments showed that the pharmacodynamic indicators were significantly different among different specifications of Notoginseng Radix et Rhizoma. The spectrum-effect relationship was explored between 27 common components and pharmacodynamic indicators. Among them, 16 components had positive effects on the pharmacodynamic indicators of Notoginseng Radix et Rhizoma, and 11 exerted negative effects. This study provides a basis for the precision medication and quality control of Notoginseng Radix et Rhizoma.

RNA N6-methyladenosine demethylase FTO promotes breast tumor progression through inhibiting BNIP3.

BACKGROUND: N6-methyladenosine (m6A) modification is the most pervasive modification in mRNA, and has been considered as a new layer of epigenetic regulation on mRNA processing, stability and translation. Despite its functional significance in various physiological processes, the role of the m6A modification involved in breast cancer is yet fully understood. METHODS: We used the m6A-RNA immunoprecipitation sequencing to identify the potential targets in breast cancer. To determine the underlying mechanism for the axis of FTO-BNIP3, we performed a series of in vitro and in vivo assays in 3 breast cancer cell lines and 36 primary breast tumor tissues and 12 adjunct tissues. RESULTS: We showed that FTO, a key m6A demethylase, was up-regulated in human breast cancer. High level of FTO was significantly associated with lower survival rates in patients with breast cancer. FTO promoted breast cancer cell proliferation, colony formation and metastasis in vitro and in vivo. We identified BNIP3, a pro-apoptosis gene, as a downstream target of FTO-mediated m6A modification. Epigenetically, FTO mediated m6A demethylation in the 3'UTR of BNIP3 mRNA and induced its degradation via an YTHDF2 independent mechanism. BNIP3 acts as a tumor suppressor and is negatively correlated with FTO expression in clinical breast cancer patients. BNIP3 dramatically alleviated FTO-dependent tumor growth retardation and metastasis. CONCLUSIONS: Our findings demonstrate the functional significance of the m6A modification in breast cancer, and suggest that FTO may serve as a novel potential therapeutic target for breast cancer.

The ATM kinase induces microRNA biogenesis in the DNA damage response.

The DNA damage response involves a complex network of processes that detect and repair DNA damage. Here we show that miRNA biogenesis is globally induced upon DNA damage in an ATM-dependent manner. About one-fourth of miRNAs are significantly upregulated after DNA damage, while loss of ATM abolishes their induction. KH-type splicing regulatory protein (KSRP) is a key player that translates DNA damage signaling to miRNA biogenesis. The ATM kinase directly binds to and phosphorylates KSRP, leading to enhanced interaction between KSRP and pri-miRNAs and increased KSRP activity in miRNA processing. Mutations of the ATM phosphorylation sites of KSRP impaired its activity in regulating miRNAs. These findings reveal a mechanism by which DNA damage signaling is linked to miRNA biogenesis.

A novel non-coding RNA lncRNA-JADE connects DNA damage signalling to histone H4 acetylation.

A prompt and efficient DNA damage response (DDR) eliminates the detrimental effects of DNA lesions in eukaryotic cells. Basic and preclinical studies suggest that the DDR is one of the primary anti-cancer barriers during tumorigenesis. The DDR involves a complex network of processes that detect and repair DNA damage, in which long non-coding RNAs (lncRNAs), a new class of regulatory RNAs, may play an important role. In the current study, we identified a novel lncRNA, lncRNA-JADE, that is induced after DNA damage in an ataxia-telangiectasia mutated (ATM)-dependent manner. LncRNA-JADE transcriptionally activates Jade1, a key component in the HBO1 (human acetylase binding to ORC1) histone acetylation complex. Consequently, lncRNA-JADE induces histone H4 acetylation in the DDR. Markedly higher levels of lncRNA-JADE were observed in human breast tumours in comparison with normal breast tissues. Knockdown of lncRNA-JADE significantly inhibited breast tumour growth in vivo. On the basis of these results, we propose that lncRNA-JADE is a key functional link that connects the DDR to histone H4 acetylation, and that dysregulation of lncRNA-JADE may contribute to breast tumorigenesis.

miRNA response to DNA damage.

Faithful transmission of genetic material in eukaryotic cells requires not only accurate DNA replication and chromosome distribution but also the ability to sense and repair spontaneous and induced DNA damage. To maintain genomic integrity, cells undergo a DNA damage response using a complex network of signaling pathways composed of coordinate sensors, transducers and effectors in cell cycle arrest, apoptosis and DNA repair. Emerging evidence has suggested that miRNAs play a crucial role in regulation of DNA damage response. In this review, we discuss the recent findings on how miRNAs interact with the canonical DNA damage response and how miRNA expression is regulated after DNA damage.

MiR-137 regulates epithelial-mesenchymal transition in gastrointestinal stromal tumor.

Activation of the epithelial-to-mesenchymal transition (EMT) endows extraordinary invasive capability of cancer cells and causes of treatment failure and metastasis in gastrointestinal stromal tumor (GIST); however, the molecular mechanisms governing GIST invasion remain largely unknown. MicroRNAs (miRNAs) have been shown to play critical roles in cell motility and invasion, which promotes us to study the biological functions of miR-137 in the EMT of GIST. We have found that miR-137 was dramatically downregulated in clinical specimen of GIST. Using an in silico analysis approach, Twist1, a key regulator gene of EMT, has been identified as the target of miR-137. Quantitative RT-PCT and western blot were used to confirm that miR-137 directly targeted on Twist1 and repressed Twist1 expression in GIST-H1 human gastrointestinal stromal tumor cell line. Further, miR-137 was found to increase expression of E-cadherin and cytokeratin, but suppress expression of N-cadherin and vimentin. In vitro experiments have shown that miR-137 enhanced the epithelial cell morphology, decreased GIST cell migration, activated G1 cell cycle arrest, and induced cell apoptosis. These results suggest a novel mechanism that miR-137 regulates EMT and inhibits cell migration via Twist1 downregulation. Therefore, miR-137 may function as anti-migration and anti-metastasis in GIST and our study provides a potential approach for developing miR-137-based therapeutic strategy for GIST.

Integrating genome-wide CRISPR screens and in silico drug profiling for targeted antidote development.

Numerous toxins threaten humans, but specific antidotes are unavailable for most of them. Although CRISPR screening has aided the discovery of the mechanisms of some toxins, developing targeted antidotes remains a significant challenge. Recently, we established a systematic framework to develop antidotes by combining the identification of novel drug targets by using a genome-wide CRISPR screen with a virtual screen of drugs approved by the US Food and Drug Administration. This approach allows for a comprehensive understanding of toxin mechanisms at the whole-genome level and facilitates the identification of promising antidote drugs targeting specific molecules. Here, we present step-by-step instructions for executing genome-scale CRISPR-Cas9 knockout screens of toxins in HAP1 cells. We also provide detailed guidance for conducting an in silico drug screen and an in vivo drug validation. By using this protocol, it takes ~4 weeks to perform the genome-scale screen, 4 weeks for sequencing and data analysis, 4 weeks to validate candidate genes, 1 week for the virtual screen and 2 weeks for in vitro drug validation. This framework has the potential to accelerate the development of antidotes for a wide range of toxins and can rapidly identify promising drug candidates that are already known to be safe and effective. This could lead to the development of new antidotes much more quickly than traditional methods, protecting lives from diverse toxins and advancing human health.