CRISPR/CasΦ2-mediated gene editing in wheat and rye.

The compact CRISPR/CasΦ2 system provides a complementary genome engineering tool for efficient gene editing including cytosine and adenosine base editing in wheat and rye with high specificity, efficient use of the protospacer-adjacent motif TTN, and an alternative base-editing window.

Relationship between PPAR-γ gene polymorphisms and ischemic stroke risk: A meta-analysis.

BACKGROUND: Published researches have suggested some associations between PPAR-γ and ischemic stroke (IS) development. This meta-analysis was conducted to evaluate the association between PPAR-γ gene polymorphisms and IS risk. MATERIALS AND METHODS: A systematic search was conducted in PubMed, Embase, Web of Science, China National Knowledge Infrastructure, and WanFang databases. The pooled association of odd ratios (ORs) and its 95% confidence interval (CI) was calculated to assess the IS risk of PPAR-γ rs1801282 C/G and rs3856806 C/T polymorphisms. Furthermore, the heterogeneity test, cumulative analyses, sensitivity analyses, and publication bias were conducted. RESULT: Sixteen publications with 3786 cases and 5343 controls were identified. Overall findings indicated that rs1801282 C/G polymorphism may be associated with an increased risk for IS (GG vs. CC: OR = 2.17 95%CI = 1.09-4.35, p = .03, I2  = 0%; GG vs. CC+CG: OR = 2.15, 95%CI = 1.07-4.32, p = .03, I2  = 0%). The similar results were also found in the subgroup analysis. In addition, no significant association was observed between rs3856806 C/T polymorphism and IS risk. CONCLUSION: In conclusion, our study showed that PPAR-γ rs1801282 C/G polymorphism probably plays an important role in IS occurrence. The result should be verified with more studies in the future.

Plasma Long Non-Coding RNA RP11-438N5.3 as a Novel Biomarker for Non-Small Cell Lung Cancer.

BACKGROUND: Lung cancer is one of the most common malignancies around the world. The lack of early diagnosis and effective treatment strategies contributes to the poor prognosis of patients with lung cancer. Recent studies have implied the role of long non-coding RNAs (lncRNAs) in oncogenesis. The purpose of our study was to identify specific lncRNAs which were correlated with non-small cell lung cancer (NSCLC) and their potential functions. MATERIALS AND METHODS: The global plasma lncRNA profiling was performed using LncPathTM Human Cancer Array, and 11 lncRNAs were then selected for quantitative reverse transcription PCR (qRT-PCR) validation in 138 plasma samples from 69 NSCLC patients and 69 healthy controls (HCs). A noteworthy lncRNA, RP11-438N5.3, the function of which was previously unknown, was further explored on the aspect of the correlation of its expression level with clinicopathological factors. RESULTS: The results revealed that plasma level of RP11-438N5.3 was significantly lower in NSCLCs than that in HCs (p <0.01). Receiver operating characteristic (ROC) analyses showed that the area under the ROC curve (AUC) for plasma RP11-438N5.3 was 0.814 (95% CI, 0.743-0.885; p<0.01). High expression of RP11-438N5.3 in plasma correlated with favorable prognosis for NSCLC patients (Hazard ratio = 2.827; 95% CI: 1.036 to 7.718; p = 0.024; Cox regression analysis). Moreover, we found that the plasma level of stromal interaction molecule 1 (STIM1) mRNA was remarkably higher in NSCLC compared with HC (p<0.01), and the AUC for STIM1 was 0.753 (95% CI, 0.673-0.833; p<0.01), RP11-438N5.3 and STIM1 were inversely correlated with each other. CONCLUSION: Our results indicated that RP11-438N5.3 and STIM1 might provide a new strategy for NSCLC diagnosis. Furthermore, increased circulating RP11-438N5.3 level holds great potential in indicating a beneficial prognosis in NSCLC patients.

Manipulating gene translation in plants by CRISPR-Cas9-mediated genome editing of upstream open reading frames.

Gene expression is regulated by multiple processes, and the translation of mRNAs into proteins is an especially critical step. Upstream open reading frames (uORFs) are widespread cis-elements in eukaryotic genes that usually suppress the translation of downstream primary ORFs (pORFs). Here, we describe a protocol for fine-tuning gene translation in plants by editing endogenous uORFs with the CRISPR-Cas9 system. The method we present readily yields transgene-free uorf mutant offspring. We provide detailed protocols for predicting uORFs and testing their effects on downstream pORFs using a dual-luciferase reporter system, designing and constructing single guide RNA (sgRNA)-Cas9 vectors, identifying transgene-free uorf mutants, and finally comparing the mRNA, protein and phenotypic levels of target genes in uorf mutants and controls. Predicting uORFs and confirming their effects in protoplasts takes only 2-3 weeks, and transgene-free mutants with edited target uORFs controlling different levels of pORF translation can be obtained within 4 months. Unlike previous methods, our strategy achieves fine-tuning of gene translation in transgene-free derivatives, which accelerates the analysis of gene function and the improvement of crop traits.

Conferring DNA virus resistance with high specificity in plants using virus-inducible genome-editing system.

The CRISPR/Cas9 system has recently been engineered to confer resistance to geminiviruses in plants. However, we show here that the usefulness of this antiviral strategy is undermined by off-target effects identified by deep sequencing in Arabidopsis. We construct two virus-inducible CRISPR/Cas9 vectors that efficiently inhibit beet severe curly top virus (BSCTV) accumulation in both transient assays (Nicotiana benthamiana) and transgenic lines (Arabidopsis). Deep sequencing detects no off-target effect in candidate sites of the transgenic Arabidopsis. This kind of virus-inducible genome-editing system should be widely applicable for generating virus-resistant plants without off-target costs.

The Histone H3 Lysine 4 Presenter WDR5 as an Oncogenic Protein and Novel Epigenetic Target in Cancer.

The histone H3 lysine 4 (H3K4) presenter WDR5 forms protein complexes with H3K4 methyltransferases MLL1-MLL4 and binding partner proteins including RBBP5, ASH2L, and DPY30, and plays a key role in histone H3K4 trimethylation, chromatin remodeling, transcriptional activation of target genes, normal biology, and diseases such as MLL-rearranged leukemia. By forming protein complexes with other proteins such as Myc, WDR5 induces transcriptional activation of key oncogenes, tumor cell cycle progression, DNA replication, cell proliferation, survival, tumor initiation, progression, invasion, and metastasis of cancer of a variety of organ origins. Several small molecule MLL/WDR5 protein-protein interaction inhibitors, such as MM-401, MM-589, WDR5-0103, Piribedil, and OICR-9429, have been confirmed to reduce H3K4 trimethylation, oncogenic gene expression, cell cycle progression, cancer cell proliferation, survival and resistance to chemotherapy without general toxicity to normal cells. Derivatives of the MLL/WDR5 interaction inhibitors with improved pharmacokinetic properties and in vivo bioavailability are expected to have the potential to be trialed in cancer patients.

Domestication of wild tomato is accelerated by genome editing.

Crop improvement by inbreeding often results in fitness penalties and loss of genetic diversity. We introduced desirable traits into four stress-tolerant wild-tomato accessions by using multiplex CRISPR-Cas9 editing of coding sequences, cis-regulatory regions or upstream open reading frames of genes associated with morphology, flower and fruit production, and ascorbic acid synthesis. Cas9-free progeny of edited plants had domesticated phenotypes yet retained parental disease resistance and salt tolerance.

Genome editing of upstream open reading frames enables translational control in plants.

Translational regulation by upstream open reading frames (uORFs) is becoming established as a general mechanism for controlling the amount of protein that is synthesized from downstream primary ORFs (pORFs). We found that genome editing of endogenous uORFs in plants enabled the modulation of translation of mRNAs from four pORFs that are involved in either development or antioxidant biosynthesis. A single-guide RNA that targeted the region harboring a uORF initiation codon can produce multiple mutations. Following uORF editing, we observed varying amounts of mRNA translation in four pORFs. Notably, editing the uORF of LsGGP2, which encodes a key enzyme in vitamin C biosynthesis in lettuce, not only increased oxidation stress tolerance, but also increased ascorbate content by ∼150%. These data indicate that editing plant uORFs provides a generalizable, efficient method for manipulating translation of mRNA that could be applied to dissect biological mechanisms and improve crops.

The anti-malarial atovaquone selectively increases chemosensitivity in retinoblastoma via mitochondrial dysfunction-dependent oxidative damage and Akt/AMPK/mTOR inhibition.

Mitochondria has been identified as a promising target in several cancers. However, little is known on the effects of targeting mitochondria in retinoblastoma. In this work, we show that anti-malarial atovaquone, at clinically achievable concentration, demonstrates inhibitory effects to retinoblastoma cells, to a more extent than in normal retinal cells. Atovaquone also significantly increases chemosensitivity in retinoblastoma. Importantly, we show that retinoblastoma cells have higher level of mitochondrial respiration, membrane potential, mass and ATP compared to normal retinal cells. Although atovaquone significantly inhibits mitochondrial respiration and decrease ATP level in both malignant and normal retinal cells in a similar manner, atovaquone induces much more oxidative stress and damage in retinoblastoma than normal retinal cells. These suggest that normal retinal cells are more tolerable to mitochondrial dysfunctions than retinoblastoma cells. We further demonstrate that atovaquone targets Akt/AMPK/mTOR signaling via inducing mitochondrial dysfunction. Our pre-clinical work demonstrates the translational potential of atovaquone as an addition to the treatment armamentarium for retinoblastoma. Our work also demonstrates the differences of mitochondrial biogenesis and function in malignant versus normal retinal cells which are important for the targeted therapy in retinoblastoma.

Plasma long non-coding RNA MALAT1 is associated with distant metastasis in patients with epithelial ovarian cancer.

Human metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a newly identified metastasis-associated long non-coding RNA. In a previous study, it was identified that plasma levels of MALAT1 were significantly increased in gastric cancer patients with metastasis compared with gastric cancer patients without metastasis and healthy control individuals. However, it is unclear whether plasma levels of MALAT1 may act as a biomarker for evaluating the development of metastasis in epithelial ovarian cancer (EOC). In the present study, groups that consisted of 47 patients with EOC and metastasis (EOC/DM), 47 patients with EOC without metastasis (EOC/NDM), and 47 healthy control (HC) individuals were established. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect the level of plasma MALAT1 in these groups. The results showed that levels of plasma MALAT1 were significantly increased in the EOC/DM group compared with the EOC/NDM and HC groups (P<0.001). Receiver operating characteristic (ROC) analysis indicated that plasma MALAT1 yielded an area under the curve (AUC) of 0.820 [95% confidence interval (CI), 0.734-0.905; P<0.001], distinguishing between EOC/DM and EOC/NDM. ROC analysis also yielded an AUC of 0.884 (95% CI, 0.820-0.949; P<0.001), with 89.4% sensitivity and 72.3% specificity for distinguishing between EOC/DM and HC. Furthermore, multivariate analysis indicated that overexpression of MALAT1, differentiation (poor), tumor-node-metastasis stage (IV), lymph node metastasis (N3), peritoneal invasion (present) and higher serum carbohydrate antigen 125 levels were independent predictors of survival (hazard ratio, 3.322; P=0.028) in patients with EOC. Kaplan-Meier analysis revealed that patients with increased MALAT1 expression had a poorer disease-free survival time. In conclusion, the levels of plasma MALAT1 may act as a valuable biomarker for the diagnosis of metastasis.

[Association between single nucleotide polymorphisms of 5'-untranslated region of GPx4 gene and male infertility].

OBJECTIVE: To study the association between the single nucleotide polymorphisms (SNPs) of the 5'-untranslated region (5'-UTR) of phospholipid hydroperoxide glutathione peroxidase (GPx4 or PHGPx) gene and oligo- or asthenozoospermic male infertility. METHODS: The 5'-UTR region of the GPx4 gene was amplified from infertile men and controls using the polymerase chain reaction and was analyzed for polymorphisms by direct sequencing. RESULTS: A total of 9 SNPs were present in the cohort, however there were no significant differences in these 9 SNPs between the case and control groups. According to the results of linkage disequilibrium analysis and haplotype construction, one haplotype (rs757229-rs757230-rs4588110-rs3746165-rs3746166: C-G-G-T-A) was present only in the control men, and significant difference was detected(P< 0.01). CONCLUSION: The SNPs of 5'-UTR region of the GPx4 gene might not be associated with oligo- or asthenozoospermic male infertility. However, the haplotype (rs757229-rs757230-rs4588110- rs3746165-rs3746166: C-G-G-T-A) might be a protective haplotype.