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Background Guanine-rich sequences are able to form complex RNA structures termed RNA G-quadruplexes in vitro. Because of their high stability, RNA G-quadruplexes are proposed to exist in vivo and are suggested to be associated with important biological relevance. However, there is a lack of direct evidence for RNA G-quadruplex formation in living eukaryotic cells. Therefore, it is unclear whether any purported functions are associated with the specific sequence content or the formation of an RNA G-quadruplex structure. Results Using rG4-seq, we profile the landscape of those guanine-rich regions with the in vitro folding potential in the Arabidopsis transcriptome. We find a global enrichment of RNA G-quadruplexes with two G-quartets whereby the folding potential is strongly influenced by RNA secondary structures. Using in vitro and in vivo RNA chemical structure profiling, we determine that hundreds of RNA G-quadruplex structures are strongly folded in both Arabidopsis and rice, providing direct evidence of RNA G-quadruplex formation in living eukaryotic cells. Subsequent genetic and biochemical analyses show that RNA G-quadruplex folding is able to regulate translation and modulate plant growth. Conclusions Our study reveals the existence of RNA G-quadruplex in vivo and indicates that RNA G-quadruplex structures act as important regulators of plant development and growth.

[EN] MicroRNA (miRNA)-mediated cleavage is involved in numerous essential cellular pathways. miRNAs recognize target RNAs via sequence complementarity. In addition to complementarity, in vitro and in silico studies have suggested that RNA structuremay influence the accessibility of mRNAs to miRNA-induced silencing complexes (miRISCs), thereby affecting RNA silencing. However, the regulatory mechanism of mRNA structure in miRNA cleavage remains elusive. We investigated the role of in vivo RNA secondary structure in miRNA cleavage by developing the new CAP-STRUCTURE-seq method to capture the intact mRNA structurome in Arabidopsis thaliana. This approach revealed that miRNA target sites were not structurally accessible for miRISC binding prior to cleavage in vivo. Instead, we found that the unfolding of the target site structure plays a key role in miRISC activity in vivo. We found that the single-strandedness of the two nucleotides immediately downstream of the target site, named Target Adjacent nucleotideMotif, can promotemiRNA cleavage but not miRNA binding, thus decoupling target site binding from cleavage. Our findings demonstrate that mRNA structure in vivo can modulate miRNA cleavage, providing evidence of mRNA structure-dependent regulation of biological processes., Biotechnology and Biological Sciences Research Council [BB/L025000/1]; the NorwichResearch Park Science Links Seed Fund; and European Commission Horizon 2020 European Research Council, Starting Grant [680324]. Funding for open access charge: Biotechnology and Biological Sciences Research Council [BB/L025000/1]; the Norwich Research Park Science Links Seed Fund; and European Commission Horizon 2020 European Research Council, Starting Grant [680324].

Seed size is a key agronomic trait that greatly determines plant yield. Elucidating the molecular mechanism underlying seed size regulation is also an important question in developmental biology. Here, we show that the KIX-PPD-MYC-GIF1 pathway plays a crucial role in seed size control in Arabidopsis thaliana. Disruption of KIX8/9 and PPD1/2 causes large seeds due to increased cell proliferation and cell elongation in the integuments. KIX8/9 and PPD1/2 interact with transcription factors MYC3/4 to form the KIX-PPD-MYC complex in Arabidopsis. The KIX-PPD-MYC complex associates with the typical G-box sequence in the promoter of GRF-INTERACTING FACTOR 1 (GIF1), which promotes seed growth, and represses its expression. Genetic analyses support that KIX8/9, PPD1/2, MYC3/4, and GIF1 function in a common pathway to control seed size. Thus, our results reveal a genetic and molecular mechanism by which the transcription factors MYC3/4 recruit KIX8/9 and PPD1/2 to the promoter of GIF1 and repress its expression, thereby determining seed size in Arabidopsis., Seed size is an important determinant of plant yield. Here, Liu et al. show that a KIX-PPD repressor complex and MYC transcription factors interact with the G-box motif in the promoter of GRF-INTERACTING FACTOR 1 to regulate seed size by influencing cell proliferation and elongation in the integument.

The low activity of nanozymes, which work as an alternative to natural enzymes, limits their applications in the fabrication of biosensors, drawing increasing attention aimed at improving their catalytic capacity. In this work, the peroxidase-like activity of MoS2 nanosheets (NSs) was dramatically enhanced through DNA modification, and was 4.3-times higher than that of bare MoS2 NSs. Such an enhancement of catalytic activity was mainly ascribed to the increased affinity of the DNA/MoS2 NSs toward the substrate, TMB, further accelerating electron transfer from TMB to H2O2. On the basis of DNA-tuned MoS2 NS nanozyme activity, a colorimetric sensing platform was developed for the facile detection of carcinoembryonic antigen (CEA) in a sensitive manner. Interestingly, a convenient, affordable, and instrument-free portable test kit was fabricated to visually monitor CEA via rooting the aptamer/MoS2 NS system into an agarose hydrogel. Importantly, our work illuminates the feasibility of using DNA to enhance the catalysis of nanozymes and their application potential in the label-free, portable, and visual detection of aptamer-targeted biomolecules.

Endoreduplication, the replication of the nuclear genome in the absence of mitosis, is often associated with cell growth and differentiation in plants and animals, but the molecular mechanisms underlying endoreduplication in plants have not been fully elucidated. Here, we show that the Mediator complex subunit MED16 acts as a negative regulator of endoreduplication to influence cell growth in Arabidopsis (Arabidopsis thaliana). The med16 mutant exhibits larger and more numerous cells than the wild type, resulting in enlarged organs. The large cells in med16 are associated with high DNA ploidy levels. MED16 associates with the promoters of the Anaphase Promoting Complex/Cyclosome activators CELL CYCLE SWITCH52 A1 (CCS52A1) and CCS52A2 (encoding important factors for endoreduplication and cell growth) and represses their expression. MED16 interacts physically with the transcriptional repressor DEL1 to repress the expression of CCS52A2. Genetic analysis suggested that MED16 is partially dependent on CCS52A1/A2 to control endoreduplication and cell growth. Our results indicate that the transcriptional repression of CCS52A1/A2 by MED16 regulates endoreduplication and cell growth in Arabidopsis.

This study developed a novel method for the rapid detection of Escherichia coli (E. coli) O157:H7 on a microfluidic platform. First, the concentration of bacteria in a sample was determined with the adenosine triphosphate (ATP) method. Then, the specific detection of E. coli was achieved in a microfluidic chip by the immune-microsphere technique. The influences of the culture time, flow rate and capture time on the detection of the target bacteria were investigated systematically. Generally, with increasing capture time, more bacteria could be captured by the microspheres, which had a positive effect on bacterial detection. Furthermore, the sensitivity and specificity of the method were also tested. The results showed that this method could specifically detect E. coli with a sensitivity as high as 49.1 cfu/μL; the consumption of bacteria was 1 μL, and the reagent was at the microliter level. The testing time can be controlled within one and a half hours, and the cost of testing was approximately RMB 10. The method described in this article is simple and accurate and has great application value in bacterial detection for medical diagnostics.

Background Excision Repair Cross-Complementation group 6-like (ERCC6L) has been shown to exhibit carcinogenic effect in several malignant tumors. However, the function and molecular mechanism of the ERCC6L in hepatocellular carcinoma (HCC) have not been investigated extensively. Methods Immunohistochemistry analyses were used to detect ERCC6L expression in a HCC tissue microarray, and the Chi-square test was used to assess the correlation between ERCC6L expression and patients’ clinicopathological features. shRNA was used to down-regulation ERCC6L expression in HCC cell lines. MTT assay, plate clone formation assay, flow cytometry, caspase 3/7 activity and migration assays were performed to evaluate the impact of ERCC6L on HCC cells in vitro. Nude mice xenograft models were used to assess the role of ERCC6L in vivo. The regulatory of mechanism of PI3K/AKT pathway was evaluated by western blotting. Results ERCC6L was highly expressed in HCC tissue compared with tumor adjacent tissues in 90 paired samples. ERCC6L expression positively correlated with gender, tumor encapsulation, and pathological stage. Patients with low ERCC6L expression had significantly longer OS than those with high ERCC6L expression. Knockdown of ERCC6L expression significantly inhibited proliferation, invasion and metastasis in vitro and tumor growth in vivo, and it promoted cell cycle arrest and apoptosis. Mechanistic analyses revealed that PI3K/AKT and NF-κB signaling pathway were inhibited by silencing ERCC6L. Conclusion These results demonstrate that ERCC6L plays a critical role in HCC progression, and thereby might be a potential therapeutic target for HCC patients.

Background Cancer stem cells (CSCs) have been proposed to be responsible for tumor recurrence and chemo-resistance. Previous studies suggested that miR-153 played essential roles in lung cancer. However, the molecular mechanism of miR-153 in regulating the stemness of non-small cell lung cancer (NSCLC) remains poorly understood. In this study, we investigated the role of miR-153 in regulation of the stemness of NSCLC. Methods The stemness property of lung stem cancer cells was detected by sphere formation assay, immunofluorescence, and Western blot. Luciferase reporter assay was performed to investigate the direct binding of miR-153 to the 3′-UTR of JAG1 mRNA. Animal study was conducted to evaluate the effect of miR-153 on tumor growth in vivo. The clinical relevance of miR-153 in NSCLC was evaluated by Rt-PCR and Kaplan-Meier analysis. Results MiR-153 expression was decreased in lung cancer tissues. Reduced miR-153 expression was associated with lung metastasis and poor overall survival of lung cancer patients. Jagged1, one of the ligands of Notch1, is targeted by miR-153 and inversely correlates with miR-153 in human lung samples. More importantly, we found that miR-153 inhibited stem cell-like phenotype and tumor growth of lung adenocarcinoma through inactivating the Jagged1/Notch1 axis. Conclusion MiR-153 suppresses the stem cell-like phenotypes and tumor growth of lung adenocarcinoma by targeting Jagged1 and provides a potential therapeutic target in lung cancer therapy.

Multitarget inhibitors design has generated great interest in cancer treatment. Based on the synergistic effects of topoisomerase and histone deacetylase inhibitors, we designed and synthesized a new series of acridine hydroxamic acid derivatives as potential novel dual Topo and HDAC inhibitors. MTT assays indicated that all the hybrid compounds displayed good antiproliferative activities with IC50 values in low micromolar range, among which compound 8c displayed potent activity against U937 (IC50 = 0.90 μM). In addition, compound 8c also displayed the best HDAC inhibitory activity, which was several times more potent than HDAC inhibitor SAHA. Subsequent studies indicated that all the compounds displayed Topo II inhibition activity at 50 μM. Moreover, compound 8c could interact with DNA and induce U937 apoptosis. This study provides a suite of compounds for further exploration of dual Topo and HDAC inhibitors, and compound 8c can be a new dual Topo and HDAC inhibitory anticancer agent.

MicroRNAs (miRNAs) are a class of small non-coding RNAs that repress gene expression. In plants, the RNase III enzyme Dicer-like (DCL1) processes primary miRNAs (pri-miRNAs) into miRNAs. Here, we show that SMALL1 (SMA1), a homolog of the DEAD-box pre-mRNA splicing factor Prp28, plays essential roles in miRNA biogenesis in Arabidopsis. A hypomorphic sma1-1 mutation causes growth defects and reduces miRNA accumulation correlated with increased target transcript levels. SMA1 interacts with the DCL1 complex and positively influences pri-miRNA processing. Moreover, SMA1 binds the promoter region of genes encoding pri-miRNAs (MIRs) and is required for MIR transcription. Furthermore, SMA1 also enhances the abundance of the DCL1 protein levels through promoting the splicing of the DCL1 pre-mRNAs. Collectively, our data provide new insights into the function of SMA1/Prp28 in regulating miRNA abundance in plants.

The ability to recover from drought stress after re‐watering is an important feature that will enable plants to cope with the predicted increase in episodic drought. The effects of pre‐drought and re‐watering conditions on leaf spectral properties and their relationships with the biochemical processes that underlie the recovery from pre‐drought conditions should be better understood. The reflectance spectra, 10 spectral reflectance indices (SRIs) and biochemical characteristics of maize (Zea mays) leaves were monitored 7, 14, 21 and 28 days after the initiation of soil drought stress during two successive cycles of drought and re‐watering periods. The leaf reflectance of the two inbred maize lines increased under the drought stress, especially in the visible spectral range. In addition, an obvious recovery of the leaf reflectance was only observed in the first re‐watering period, and its value remained higher than that of the control plants during the second recovery period. A recovery lag in the pigment contents was also observed during the second cycle. The recovery variations in the pattern and magnitude of the SRIs and the total contents of C, N and P that were measured in response to the re‐watering during both cycles were diverse and complex; both full and partial recoveries were observed. The SRIs representing different physiological attributes of plant growth, including the water index, red edge position, photochemical reflectance index and near‐infrared reflectance at 800 nm, showed strong linear relationships (P < 0.01 or 0.05) with the growth and biochemical traits across the successive drought and re‐watering cycles. The results suggest that maize plants can adjust their leaf reflectance properties and employ growth and biochemical strategies to adapt to cyclic drought stress and recover from drought stress after re‐watering.

mRNA processing is critical for gene expression. A challenge in regulating mRNA processing is how to recognize the actual mRNA processing sites, such as splice and polyadenylation sites, when the sequence content is insufficient for this purpose. Previous studies suggested that RNA structure affects mRNA processing. However, the regulatory role of RNA structure in mRNA processing remains unclear. Here, we performed in vivo selective 2’-hydroxyl acylation analysed by primer extension (SHAPE) chemical profiling on Arabidopsis nuclear RNAs and generated the in vivo nuclear RNA structure landscape. We found that nuclear mRNAs fold differently from cytosolic mRNAs. Notably, we discovered a two-nucleotide single-stranded RNA structure feature upstream of 5’ splice sites that is strongly associated with splicing and the selection of alternative 5’ splice sites. Moreover, we found the single-strandedness of branch point is also associated with 3’ splice site recognition. We also identified an RNA structure feature comprising two close-by single-stranded regions that is specifically associated with both polyadenylation and alternative polyadenylation events. Our work demonstrates an RNA structure regulatory mechanism for mRNA processing.

To achieve lung cancer gene therapy, nanocarriers decorated with different ligands were used. Surface decoration and nanoparticulate system will assist in targeting the gene to specific cells and tissues, such as cancers and diseased organs. The aim of this research was to develop a dual ligand-decorated nanocarriers, which could target the tumor cells through receptor-mediated pathways to increase the uptake of genetic materials. Transferrin (Tf) and hyaluronic (HA) containing polyethylene glycol-distearoylphosphatidylethanolamine (Tf-PEG-DSPE and HA-PEG-DSPE) ligands were synthesized. Novel Tf and HA ligand-decorated, plasmid-enhanced green fluorescent protein loaded nanostructured lipid carriers (Tf/HA-pDNA NLC) was constructed. Physicochemical properties such as morphology, size, and ζ-potential as well as release properties were evaluated. The in vitro and in vivo gene transfection efficiency of Tf/HA-pDNA NLC was evaluated in lung adenocarcinoma A549 cells and lung cancer bearing animal models. Tf/HA-pDNA NLC displayed significantly higher transfection efficiency than undecorated DNA-NLCs and single ligand-decorated NLCs in vitro and in vivo. The newly constructed NLCs could successfully load gene; and Tf and HA functioned as excellent targeting ligands to improve the cell targeting ability of the gene-loaded nanocarriers. The resulting dual ligands decorated vectors could be a promising targeted gene delivery system for the lung cancer treatment.

Melatonin acts as a crucial signaling and antioxidant molecule with multiple physiological functions in organisms. To explore effects of exogenous melatonin on postharvest browning and its possible mechanisms in litchi fruit, 'Ziniangxi' litchi fruits were treated with an aqueous solution of melatonin at 0.4 mM and then stored at 25 °C for 8 days. The results revealed that melatonin strongly suppressed pericarp browning and delayed discoloration during storage. Melatonin treatment reduced relative membrane-leakage rate and inhibited the generation of superoxide radicals (O2-·), hydrogen peroxide (H2O2), and malondialdehyde (MDA). Melatonin treatment markedly promoted the accumulation of endogenous melatonin; delayed loss of total phenolics, flavonoids, and anthocyanins; and enhanced the activities of antioxidant enzymes, including superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), ascorbate peroxidase (APX, EC 1.11.1.11), and glutathione reductase (GR, EC 1.6.4.2). By contrast, the activities of browning-related enzymes including polyphenoloxidase (PPO, EC 1.10.3.1) and peroxidase (POD, EC 1.11.1.7) were reduced. In addition, melatonin treatment up-regulated the expression of four genes encoding enzymes for repair of oxidized proteins, including LcMsrA1, LcMsrA2, LcMsrB1, and LcMsB2. These findings indicate that the delay of pericarp browning and senescence by melatonin in harvested litchi fruit could be attributed to the maintenance of redox homeostasis by the improvement of the antioxidant capacity and modulation of the repair of oxidatively damaged proteins.

Sugars function as signal molecules to regulate growth, development, and gene expression in plants, yeasts, and animals. A coordination of sugar availability with phytohormone signals is crucial for plant growth and development. The molecular link between sugar availability and hormone-dependent plant growth are largely unknown. Here we report that BRI1 and BAK1 are involved in sugar-responsive growth and development. Glucose influences the physical interactions and phosphorylations of BRI1 and BAK1 in a concentration-dependent manner. BRI1 and BAK1 physically interact with G proteins that are essential for mediating sugar signaling. Biochemical data show that BRI1 can phosphorylate G protein β subunit and γ subunits, and BAK1 can phosphorylate G protein γ subunits. Genetic analyses suggest that BRI1 and BAK1 function in a common pathway with G-protein subunits to regulate sugar responses. Thus, our findings reveal an important genetic and molecular mechanism by which BR receptors associate with G proteins to regulate sugar-responsive growth and development., G-proteins regulate sugar-responsive growth in plants. Here the authors show that brassinosteroid (BR) signaling is also involved in sugar responses and present evidence that the BR receptor BRI1 and its co-receptor BAK1 can phosphorylate G-protein subunits to regulate sugar signaling in Arabidopsis.

Although seed size is one of the most important agronomic traits in plants, the genetic and molecular mechanisms that set the final size of seeds are largely unknown. We previously identified the ubiquitin receptor DA1 as a negative regulator of seed size, and the Arabidopsis thaliana da1-1 mutant produces larger seeds than the wild type. Here, we describe a B3 domain transcriptional repressor NGATHA-like protein (NGAL2), encoded by the suppressor of da1-1 (SOD7), which acts maternally to regulate seed size by restricting cell proliferation in the integuments of ovules and developing seeds. Overexpression of SOD7 significantly decreases seed size of wild-type plants, while the simultaneous disruption of SOD7 and its closest homolog DEVELOPMENT-RELATED PcG TARGET IN THE APEX4 (DPA4/NGAL3) increases seed size. Genetic analyses indicate that SOD7 and DPA4 act in a common pathway with the seed size regulator KLU to regulate seed growth, but do so independently of DA1. Further results show that SOD7 directly binds to the promoter of KLUH (KLU) in vitro and in vivo and represses the expression of KLU. Therefore, our findings reveal the genetic and molecular mechanisms of SOD7, DPA4, and KLU in seed size regulation and suggest that they are promising targets for seed size improvement in crops.

We examined the bone properties of BXD recombinant inbred (RI) mice by analyzing femur and tibia and compared their phenotypes of different compartments. 46 BXD RI mouse strains were analyzed including progenitor C57BL/6J (n=16) and DBA/2J (n=15) and two first filial generations (D2B6F1 and B6D2F1). Strain differences were observed in bone quality and structural properties (P<0.05) in each bone profile (whole bone, cortical bone, or trabecular bone). It is well known that skeletal phenotypes are largely affected by genetic determinants and genders, such as bone mineral density (BMD). While genetics and gender appear expectedly as the major determinants of bone mass and structure, significant correlations were also observed between femur and tibia. More importantly, positive and negative femur-tibia associations indicated that genetic makeup had an influence on skeletal integrity. We conclude that (a) femur-tibia association in bone morphological properties significantly varies from strain to strain, which may be caused by genetic differences among strains, and (b) strainwise variations were seen in bone mass, bone morphology, and bone microarchitecture along with bone structural property.

Objective: Lung cancer is the leading cause of cancer-related death worldwide with a relatively low 5-year relative survival rate of 16%. Novel and efficient therapeutic approach for lung cancer is desperately needed. Materials and Methods: Targeting cancer stem cells (CSCs) provides a promising strategy to eradicate malignancies. The Notch signaling pathway plays an important role in the control of cell fates and developmental processes including CSCs. The function of Notch1 in the regulation of CSCs and whether targeting Notch1 could be a potential therapy for lung cancer were explored in this study. Lung CSCs (LCSCs) were isolated from A549 cells and identified as CD44+/CD24– cells by magnetic-assisted cell sorting, then the putative LCSCs were treated with Notch1 inhibitor and Notch1 small interfering RNAs (siRNAs); the growth and proliferation of LCSCs were investigated to test the effect of Notch1 blocking on the growth and viability of LCSCs. Results: CD44+/CD24– cells isolated from A549 cells possessed stem cell-like properties with high expression of Notch1. Blocking Notch1 by inhibitor DAPT or siRNA both inhibited the growth capacity of LCSCs. Conclusion: Our discovery demonstrated a depression of growth in CD44+/CD24– and A549 cells caused by blockade of Notch signaling pathway. Further studies are needed to demonstrate the detailed effects of Notch1 blocking on the LCSCs. Nevertheless, targeting the Notch pathway has exhibited great potential to be an improved lung cancer treatment.

Although the control of organ size is a fundamental question in developmental biology, little is known about the genetic and molecular mechanisms that determine the final size of seeds in plants. We previously demonstrated that the ubiquitin receptor DA1 acts synergistically with the E3 ubiquitin ligases DA2 and ENHANCER1 OF DA1 (EOD1)/BIG BROTHER to restrict seed growth in Arabidopsis thaliana. Here, we describe UBIQUITIN-SPECIFIC PROTEASE15 (UBP15), encoded by SUPPRESSOR2 OF DA1 (SOD2), which acts maternally to regulate seed size by promoting cell proliferation in the integuments of ovules and developing seeds. The sod2/ubp15 mutants form small seeds, while overexpression of UBP15 increases seed size of wild-type plants. Genetic analyses indicate that UBP15 functions antagonistically in a common pathway with DA1 to influence seed size, but does so independently of DA2 and EOD1. Further results reveal that DA1 physically associates with UBP15 in vitro and in vivo and modulates the stability of UBP15. Therefore, our findings establish a genetic and molecular framework for the regulation of seed size by four ubiquitin-related proteins DA1, DA2, EOD1, and UBP15 and suggest that they are promising targets for increasing seed size in crops.

Aspirin is a salicylate drug that is widely used, and recently it has been shown to influence the development of various types of cancers. Our previous study revealed that aspirin had an inhibitory effect on the growth of S180 sarcoma and 3AO human ovarian cancer cells. The present study utilized a murine S180 sarcoma model to investigate the molecular mechanisms involved in aspirin-induced tumor growth inhibition. Tumor-bearing mice were randomly divided into five groups with 10 mice in each group: i) control; ii) 5-fluorouracil (5-FU); iii) high-dose aspirin (250 mg/kg); iv) low-dose aspirin (50 mg/kg); and v) combination of 5-FU and aspirin (50 mg/kg). The effect of aspirin on tumor growth was observed by measuring tumor volume and evaluating the antitumor effect. Tumor histology and immunohistochemistry were performed to detect the microvessel density (MVD), lymphatic vessel density (LVD), and the expression levels of vascular endothelial growth factor A (VEGF-A) and VEGF-C. The expression of VEGF-A and VEGF-C was also confirmed and quantified by western blotting. We discovered significant growth delay in murine S180 sarcoma as a result of aspirin treatment. The inhibition rate of tumor growth induced by high-dose and low-dose aspirin was 33.5 and 22.2%, respectively (P

OBJECTIVE To study the expression of HIF-1alpha and SDF-1/CXCR4 in repopulating H22 tumor tissue and the mechanism of angiogenesis of polypeptide extract from scorpion venom (PESV) during chemotherapy treatment. METHOD The expression of HIF-1alpha and SDF-1/CXCR4 in H22 tumor tissue was monitored by immunohistochemistry, and the expression level was determined by Qwin V3 image analyzing software. The correlation between HIF-1alpha and SDF-1 was analyzed. SDF-1 content was detected by ELISA. RESULT HIF-1alpha expression was found no difference in model group between 14 d and 21 d, and up-regulated in 28 d. There was no change of HIF-1alpha expression was observed in low-dose PESV group. In high-dose PESV group, the level of HIF-1alpha expression was high in 14 d and low in 21 d. ELISA detecting showed SDF-1 content increased slowly from 14 d to 21 d, highly from 21 d to 28 d. But in high-dose PESV groups, the content increased slowly all the time. The immunohitochemistry method got the same result with ELISA. Correlation analysis showed r = 0.805. CXCR4 expression down-regulated in two PESV treated groups, and no difference was found between these two groups. CONCLUSION HIF-1alpha and SDF-1 participated in VEGF expression and angiogenesis in tumor tissue during chemotherapy, while PESV could inhibit the expression of HIF-1alpha and SDF-I.

OBJECTIVE To study the effects of polypeptide extract from scorpion venom (PESV) alliance with chemotherapy on angiogenesis of Lewis lung carcinomas (LLC) and its mechanism. METHOD LLC cells suspension (4 x 10(6) cells/mL) were subcutaneously injected into 54 C57BL/6J mice in right armpits. Then the tumor-bearing mice were randomly divided into three groups: the control group, the chemotherapy group and the PESV group. Cyclophosphamide was used to establish the model of cancer. Chemotherapy and PESV were added to the PESV group. Every 7 days, 6 mice of each group were executed, and the experiments were carried out for 28 days. The tumor volume and inhibitory rate were determined. Immunohistochemistry and RT-PCR were used to determine the expression of factor VIII, alpha-SMA, Dll4 and Notch1 in tumor tissue. Correlation analysis was used to identify the relationship of factor VIII and calculate microvessel density (MVD), alpha-SMA and vascular maturity. RESULT The inhibitory rate of PESV was 42.21%. Comparing with the chemotherapy group, the expression of tumor factor Dll4 and Notch1 in the PESV group were decreased significantly (P < 0.05). The expression of factor VIII and alpha-SMA in the chemotherapy group is lower than the control group (P < 0.05), while it's higher when compared with the PESV group (P < 0.01). Expression of Dll4 and Notch1 in the chemotherapy group at the 28th day were higher than the control group (P < 0.05), and the expression in the PESV group at the 21st day were significantly lower than the chemotherapy group (P < 0.05). CONCLUSION PESV could inhibit the angiogenesis of LLC. It might be attained by decreasing the level of angiogenic factors, that are factor VIII, alpha-SMA, Dll4 and Notch1 in tumor microenvironment.

OBJECTIVE To study the effects of polypeptide extract from scorpion venom (PESV) on immune escape of Lewis lung carcinomas (LLC) and its mechanism. METHOD Forty C57BL/6J mice were inoculated with LLC cells suspension (1 x 10(7) cells/ mL) in right armpit subcutaneously. The tumor-bearing mice were randomly divided into two groups: the control group and the PESV group. PESV was intragastrically subjected to the mice of the experimental group for 18 days. The tumor volume and tumor inhibitory rate were determined. The expression levels of VEGF,TGF-beta1 and IL-10 in tumor microenvironment were determined by immunohisto-chemistry-staining and ELISA. Surface co-stimulatory molecules CD80 and CD86 of tumor infiltrating dendritic cells (DC) were determined by immunohistochemistry-staining and flow cytometry. RESULT The growth inhibitory rate of PESV was 56. 60%. The expression levels of VEGF,TGF-beta1 and IL-10 were decreased in tumor and serum, while the expression of co-stimulatory molecules CD80 and CD86 on DC were increased in tumor. Compared with the control group, the differences were all significant (P < 6.05). CONCLUSION PESV was effective in recovering immuno-surveillance and intervening immune escape of lung cancer through multi-pathway. And its effects might be attained by decreasing the level of VEGF, TGF-beta1 and IL-10 in tumor microenvironment and increasing the expression of co-stimulatory molecules CD80 and CD86 on DC.

OBJECTIVE To observe the inhabitive effect and mechanism of polypeptide extract from scorpion venom (PESV) on repopulation in H22 tumor cell during chemotherapy. METHOD H22 tumor cells were injected into 96 mice subcutaneously, then mice were divided into 4 groups radomly: Model, low-dose-PESV, high-dose-PESV, and control. Reppulation model was established by 5-Fu treating mice with H22. Four groups was treated differently, 6 mice of each group was sacrificed every 7 days, measured tumor volume twice one week. The expression of vascular endothelial growth factor (VEGF), proliferating cell nuclear antigen (PCNA), CD105 microvessel density (CD105-MVD) and platelet derived growth factor (PDGF) in H22 tumor issue was observed by using immunohistochemistry and grey analysis, the relation of VEGF and MVD was affirmed by correlation analysis. RESULT In control group tumor volume of H22 increased quickly in 13-24 day, and all mice died before 27 day. In model tumor volume increased quickly before 17, in 17-22 day slowly, after 22 day quickly again, and all the mice died before 31 day. In low and high dose PESV, tumor volume added slowly, and only in 17 day there was significant difference between these two groups. Immunohistochemistry showed, PCNA expression of model group in 31 day was higher than in 21, 28 day, the expression level of high and low PESV group was lower than model group all the time, only in 17 day there was significant difference between high and low PESV group. Immunohistochemitry showed, compared with high and low dose PESV group, CD105-MVD of model group was higher in 21, 28 day (P < 0.05) and in 35 day (P < 0.01), and no difference was found between high and low dose PESV. VEGF expression of model group in 35 day was higher than in 21, 28 day (P < 0.01), and model group higher than high and low dose PESV in 21, 28, 35 day. The expression of PDGF in model decreased gradually, in high and low dose PESV, the expression was lowest in 21 day. In day 35 high dose PESV higher than low dose PESV. There was positive correlation (r = 0.669) between VEGF expression and CD105-MVD. CONCLUSION PESV can inhabit repopulation of H22 tumor cell during chemotherapy, and the mechanism maybe is through anti-angiogenesis and nomalizing tumor vessels.

Liquid–liquid phase separation plays an important role in a variety of cellular processes, including the formation of membrane-less organelles, the cytoskeleton, signalling complexes, and many other biological supramolecular assemblies. Studies on the molecular basis of phase separation in cells have focused on protein-driven phase separation. In contrast, there is limited understanding on how RNA specifically contributes to phase separation. Here, we described a phase-separation-like phenomenon that SHORT ROOT (SHR) RNA undergoes in cells. We found that an RNA G-quadruplex (GQ) forms in SHR mRNA and is capable of triggering RNA phase separation under physiological conditions, suggesting that GQs might be responsible for the formation of the SHR phase-separation-like phenomenon in vivo. We also found the extent of GQ-triggered-phase-separation increases on exposure to conditions which promote GQ. Furthermore, GQs with more G-quartets and longer loops are more likely to form phase separation. Our studies provide the first evidence that RNA can adopt structural motifs to trigger and/or maintain the specificity of RNA-driven phase separation.