Exosomal circSTRBP from cancer cells facilitates gastric cancer progression via regulating miR-1294/miR-593-3p/E2F2 axis.

CircRNAs represent a new class of non-coding RNAs which show aberrant expression in diverse cancers, such as gastric cancer (GC). circSTRBP, for instance, is suggested to be overexpressed in GC cells and tissues. However, the biological role of circSTRBP in the progression of GC and the potential mechanisms have not been investigated. circSTRBP levels within GC cells and tissues were measured by RT-qPCR. The stability of circSTRBP was assessed by actinomycin D and Ribonuclease R treatment. Cell proliferation, migration, invasion and in vitro angiogenic abilities after circSTRBP knockdown were analysed through CCK-8 assay, transwell culture system and the tube formation assay. The interaction of circSTRBP with the predicted target microRNA (miRNA) was examined by RNA immunoprecipitation and luciferase reporter assays. Xenograft tumour model was established to evaluate the role of exosomal circSTRBP in the tumour formation of GC cells. circSTRBP was upregulated in GC cells and tissues, and there was an increased level of circSTRBP in GC-derived exosomes. circSTRBP in the exosomes enhanced GC cell growth and migration in vitro, which modulates E2F Transcription Factor 2 (E2F2) expression through targeting miR-1294 and miR-593-3p. Additionally, exosomal circSTRBP promoted the tumour growth of GC cells in the xenograft model. Exosomal circSTRBP is implicated in the progression of GC by modulating the activity of miR-1294/miR-593-3p/E2F2 axis.

Mining of disease-resistance genes in Crocus sativus based on transcriptome sequencing.

Introduction: Crocus sativus L. has an important medicinal and economic value in traditional perennial Chinese medicine. However, due to its unique growth characteristics, during cultivation it is highly susceptible to disease. The absence of effective resistance genes restricts us to breed new resistant varieties of C. sativus. Methods: In present study, comprehensive transcriptome sequencing was introduced to explore the disease resistance of the candidate gene in healthy and corm rot-infected C. sativus. Results and discussion: Totally, 43.72 Gb of clean data was obtained from the assembly to generate 65,337 unigenes. By comparing the gene expression levels, 7,575 differentially expressed genes (DEGs) were primarily screened. A majority of the DEGs were completely in charge of defense and metabolism, and 152 of them were annotated as pathogen recognition genes (PRGs) based on the PGRdb dataset. The expression of some transcription factors including NAC, MYB, and WRKY members, changed significantly based on the dataset of transcriptome sequencing. Therefore, this study provides us some valuable information for exploring candidate genes involved in the disease resistance in C. sativus.

Jasmonic acid regulates the biosynthesis of medicinal metabolites via the JAZ9-MYB76 complex in Salvia miltiorrhiza.

Jasmonic acid (JA) signaling pathway plays an important role in tanshinone and phenolic acid biosynthesis in Salvia miltiorrhiza. However, the specific regulatory mechanism remains largely unclear. Previous work showed that a JASMONATE ZIM-domain (JAZ) protein, SmJAZ9, acted as a repressor of tanshinone production in S. miltiorrhiza. In this study, we revealed that SmJAZ9 reduced both phenolic acid accumulation and related biosynthetic gene expression, confirming that SmJAZ9 also negatively affected phenolic acid biosynthesis. Then, we identified a novel MYB transcription factor, SmMYB76, which interacted with SmJAZ9. SmMYB76 repressed phenolic acid biosynthesis by directly downregulating SmPAL1, Sm4CL2, and SmRAS1. Further investigation demonstrated that JA mediated phenolic acids biosynthesis via SmJAZ9-SmMYB76 complex. Taken together, these findings state the molecular mechanism that SmJAZ9-SmMYB76 regulated phenolic acid biosynthesis at the transcriptional and protein levels, which provided new insights into JA signaling pathway regulating plant metabolism.

SmbHLH60 and SmMYC2 antagonistically regulate phenolic acids and anthocyanins biosynthesis in Salvia miltiorrhiza.

INTRODUCTION: Salvia miltiorrhiza is a renowned traditional Chinese medicinal plant with extremely high medicinal value, especially for cardiovascular and cerebrovascular diseases. The jasmonic acid (JA) signaling pathway plays an important role in the improved biosynthesis of secondary metabolites, which is mediated by a major transcriptional regulator, MYC2. However, the JA regulatory mechanism of secondary metabolites biosynthesis in S. miltiorrhiza is still largely unknown. OBJECTIVES: Our work focuses on the dissection of the molecular mechanism of transcriptional regulation in MeJA-mediated biosynthesis of medicinal components of S. miltiorrhiza. We examined the role of MeJA-responsive bHLH transcription factors (TFs) in improving bioactive secondary metabolites accumulation in S. miltiorrhiza. METHODS: Hairy root transformation based on CRISPR/Cas9 technique was used to decipher gene function(s). Changes in the content of phenolic acids were evaluated by HPLC. Y1H, EMSA and dual-LUC assays were employed to analyze the molecular mechanism of SmbHLH60 in the regulation on the biosynthesis of phenolic acids and anthocyanins. Y2H, BiFC and pull-down affinity assays were used to corroborate the interaction between SmbHLH60 and SmMYC2. RESULTS: Being one of the most significantly negatively regulated bHLH genes by MeJA, a new transcription factor SmbHLH60 was discovered and characterized. Over-expression of SmbHLH60 resulted in significant inhibition of phenolic acid and anthocyanin biosynthesis in S. miltiorrhiza by transcriptionally repressing of target genes such as SmTAT1 and SmDFR, whereas CRISPR/Cas9-generated knockout of SmbHLH60 resulted in the opposite effect. In addition, SmbHLH60 and SmMYC2 formed a heterodimer to antagonistically regulate phenolic acid and anthocyanin biosynthesis. CONCLUSION: Our results clarified that SmbHLH60 is a negativeregulator on the biosynthesis of phenolic acids and anthocyanins. SmbHLH60 competed with SmMYC2 in an antagonistic manner, providing new insights for the molecular mechanism of MeJA-mediated regulation on the biosynthesis of secondary metabolites in S. miltiorrhiza.

Mining of the CULLIN E3 ubiquitin ligase genes in the whole genome of Salvia miltiorrhiza.

CULLIN (CUL) proteins are E3 ubiquitin ligases that are involved in a wide variety of biological processes as well as in response to stress in plants. In Salvia miltiorrhiza, CUL genes have not been characterized and its role in plant development, stress response and secondary metabolite synthesis have not been studied. In this study, genome-wide analyses were performed to identify and to predict the structure and function of CUL of S. miltiorrhiza. Eight CUL genes were identified from the genome of S. miltiorrhiza. The CUL genes were clustered into four subgroups according to phylogenetic relationships. The CUL domain was highly conserved across the family of CUL genes. Analysis of cis-acting elements suggested that CUL genes might play important roles in a variety of biological processes, including abscission reaction acid (ABA) processing. To investigate this hypothesis, we treated hairy roots of S. miltiorrhiza with ABA. The expression of CUL genes varied obviously after ABA treatment. Co-expression network results indicated that three CUL genes might be involved in the biosynthesis of phenolic acid or tanshinone. In summary, the mining of the CUL genes in the whole genome of S. miltiorrhiza contribute novel information to the understanding of the CUL genes and its functional roles in plant secondary metabolites, growth and development.

Overexpression of SmSCR1 Promotes Tanshinone Accumulation and Hairy Root Growth in Salvia miltiorrhiza.

Lipid-soluble tanshinone is one of the main bioactive substances in the medicinal plant Salvia miltiorrhiza, and its medicinal demand is growing rapidly. Yeast extract (YE) modulates the tanshinone biosynthesis, but the underlying regulatory network remains obscure. In this study, a YE-responsive transcriptional factor Scarecrow1 (SCR1) was identified in S. miltiorrhiza from the YE-induced transcriptome dataset. SmSCR1 is located in the nucleus. Overexpression of SmSCR1 in S. miltiorrhiza roots resulted in a significantly higher accumulation of tanshinone than the control, with the highest 1.49-fold increase. We also detected upregulation of tanshinone biosynthetic genes, SmSCR1 and SmHMGR1, and distinct alteration of growth and development of the hairy roots in the overexpression lines compared to the control. An inverse phenotype was observed in SmSCR1-SRDX suppression expression lines. We found that SmSCR1 can bind to the promoter of SmCPS1 to induce its expression. This study provides new insight into the regulatory mechanism on the growth and development of hairy roots, tanshinone accumulation, and the metabolic engineering of bioactive compounds in S. miltiorrhiza.

Genome-Wide Analysis of U-box E3 Ubiquitin Ligase Family in Response to ABA Treatment in Salvia miltiorrhiza.

Plant U-box (PUB) proteins are ubiquitin ligases (E3) involved in multiple biological processes and in response to plant stress. However, the various aspects of the genome and the differences in functions between the U-box E3 (UBE3) ubiquitin ligases remain quite obscure in Salvia miltiorrhiza. The 60 UBE3 genes in the S. miltiorrhiza genome were recognized in the present study. The phylogenetic analysis, gene structure, motifs, promoters, and physical and chemical properties of the genes were also examined. Based on the phylogenetic relationship, the 60 UBE3 genes were categorized under six different groups. The U-box domain was highly conserved across the family of UBE3 genes. Analysis of the cis-acting element revealed that the UBE3 genes might play an important role in a variety of biological processes, including a reaction to the abscisic acid (ABA) treatment. To investigate this hypothesis, an ABA treatment was developed for the hairy roots of S. miltiorrhiza. Thirteen out of the UBE3 genes significantly increased after the ABA treatment. The co-expression network revealed that nine UBE3 genes might be associated with phenolic acids or tanshinone biosynthesis. The findings of the present study brought fresh and new understanding to the participation of the UBE3 gene family in plants, specifically in their biological responses mediated by the ABA. In S. miltiorrhiza, this gene family may be crucial during the ABA treatment. Significantly, the results of this study contribute novel information to the understanding of the ubiquitin ligase gene and its role in plant growth.

The Efficacy of Aspirin in Preventing the Recurrence of Colorectal Adenoma: a Renewed Meta-Analysis of Randomized Trials.

BACKGROUND: Through search the possible randomized control trials, we make a renewed meta-analysis in order to assess the impact of aspirin in preventing the recurrence of colorectal adenoma. MATERIALS AND METHODS: The Medicine/PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Chinese biomedical literature service system (SinoMed) databases were searched for the related randomized controlled trials until to the April 2016. Three different authors respectively evaluated the quality of studies and extracted data, and we used the STATA software to analyze, investigate heterogeneity between the data, using the fixed-effects model to calculate and merge data. RESULTS: 7 papers were included the renewed meta- analysis, among these studies, two pairs were identified as representing the same study population, with the only difference being the duration of follow-up. Thus there were only five papers included our meta-analysis, and one Chinese paper were also included the work. Results were categorized by the length of follow-up, different kinds of people, varied dose of oral aspirin. The relative of adenoma in patients taking aspirin vs placebo were 0.73 (95% CI 0.55-0.98, P=0.039) with 1 year follow up; 0.84 (95% CI 0.72-0.98, P=0.484) with greater than 1 year follow up; for the advanced adenoma, the RR 0.68 (95% CI 0.49-0.94, P=0.582),for one year; RR=0.75 (95% CI 0.52-1.07, P=0.552) for greater one year. Furthermore the white population could divided into two subgroups according to the different length of follow-up time. When the length of follow-up time less than 3-year, The RR of two subgroups respective were RR=0.86 (95% CI 0.76-0.98, P=0.332), I2=0%, RR=0.68 (95% CI 0.47-0.98, P=0.552), I2=64.6%, But with the extension of follow-up time greater than 2-year, with the white, oral aspirin without considering dose had no efficacy on preventing the recurrence of any adenoma, the RR was 0.86 (95% CI 0.71-1.05, P=0.302), I2=16.4%. CONCLUSIONS: This meta-analysis indicated that oral aspirin is associated with a remarkable decrease in the recurrence of any adenoma and advanced adenomas in patients follow-up for 1 year without concerning the dose of aspirin, but with the extension of follow-up time for greater than 1 year, oral aspirin can be effective on preventing the recurrence of any adenoma, but for the advanced adenoma, the result indicated that oral aspirin had no efficacy, According to the inclusion of ethnic groups, we also divided relevant papers into two subgroups as the yellow and white group. Then the follow-up time was less than 3 years, oral aspirin without considering the dose, had an significant efficacy on preventing the recurrence of any adenoma. But with the follow-up greater than 2 years, oral aspirin had no effect in the white.