不同前处理方式绞股蓝总皂甙含量的差异

用超声法提取绞股蓝鲜叶样、杀青样、烘干样、风干样以及绞股蓝袋泡茶干茶样的总皂甙,并测定其含量。结果表明,总皂甙含量为杀青样> 烘干样> 鲜叶样> 风干样> 干茶样,可能由于各处理的糖苷酶失活程度不同导致皂甙不同程度的分解,在生产和实验研究中应引起注意。     

Cytotoxic activity of gypenosides and gynogenin against non-small cell lung carcinoma A549 cells

The activity of gypenosides and gynogenin of Gynostemma pentaphyllum against non-small cell lung carcinoma (NSCLC) A549 cells was investigated to identify the structural characteristics of gypenosides and gynogenin to have anti-NSCLC activity. Of the tested dammarane-type compounds, 20S-dammar-24-en-2α,3β,12β,20-tetrol showed the strongest activity against A549 cells. Based on the structure and cytotoxic activity relationships of gypenosides and gynogenin, the OH group in C-2, the connected sugar number and the configuration in C-20 were important for cytotoxic activity against A549 cells.     

温度对绞股蓝和五柱绞股蓝生长及总皂苷积累的影响

温度是影响绞股蓝生长发育和总皂苷积累的重要环境因子之一。将绞股蓝和五柱绞股蓝幼苗置于10、15、20、25℃和30℃的光照培养箱中处理40d,检测其形态指标和总皂苷含量。结果表明:在25℃条件下,绞股蓝的叶面积、叶柄长、茎长、新萌叶片数、生物量和总叶绿素含量均为最高,五柱绞股蓝的生长发育也具有类似的规律,因此推断25℃是绞股蓝和五柱绞股蓝生长发育的适温条件。绞股蓝和五柱绞股蓝的总皂苷含量则以30℃下最高。绞股蓝的生物量和总皂苷含量决定了总皂苷产量,25～30℃最有利于提高绞股蓝的总皂苷产量,30℃则是提高五柱绞股蓝总皂苷产量的最适温度。     

动态连续逆流提取绞股蓝皂苷的研究

本文在中试条件下,通过单因素试验和正交试验考察不同因素对绞股蓝皂苷提取得率的影响,从而探讨动态连续逆流提取绞股蓝皂苷的最佳工艺。结果表明:动态连续逆流提取绞股蓝皂苷最佳条件为:提取溶剂温度为80℃,料液比为1∶35(g/mL),提取时间为50 min。在此条件下,绞股蓝提取物平均提取得率为33.95%,皂苷得率为8.9%;动态连续逆流提取绞股蓝皂苷具有生产连续性好、皂苷提取得率高、产品纯度高等优点。     

绞股蓝总皂甙含量与其营养器官和生长期相关性的研究

应用组织化学和植物化学方法,研究绞股蓝总皂甙含量与其营养器官和生长期的相关性。结果表明,不同营养器官中绞股蓝总皂甙含量叶最高,茎次之,根茎和根最低。绞股蓝地上部分总皂甙含量从营养生长→开花→结果不同生长期呈现由低→高→低的变化趋势,其中7、8、9月的开花期绞股蓝总皂甙含量达到顶峰,为药材最佳采收时间。研究还得出,绞股蓝叶的形态结构特征与其总皂甙含量相关,可作为选育绞股蓝优良品种的指标。     

Vitamin D Insufficiency in Arabs and South Asians Positively Associates with Polymorphisms in GC and CYP2R1 Genes

Background

A number of genetic studies have reported an association between vitamin D related genes such as group-specific component gene (GC), Cytochrome P450, family 2, subfamily R, polypeptide 1 (CYP2R1) and 7-dehydrocholesterol reductase/nicotinamide-adenine dinucleotide synthetase 1 (DHCR7/NADSYN1) and serum levels of the active form of Vitamin D, 25 (OH) D among African Americans, Caucasians, and Chinese. Little is known about how genetic variations associate with, or contribute to, 25(OH)D levels in Arabs populations.

Methods

Allele frequencies of 18 SNPs derived from CYP2R1, GC, and DHCR7/NADSYN1 genes in 1549 individuals (Arabs, South Asians, and Southeast Asians living in Kuwait) were determined using real time genotyping assays. Serum levels of 25(OH)D were measured using chemiluminescence immunoassay.

Results

GC gene polymorphisms (rs17467825, rs3755967, rs2282679, rs7041 and rs2298850) were found to be associated with 25(OH)D serum levels in Arabs and South Asians. Two of the CYP2R1 SNPs (rs10500804 and rs12794714) and one of GC SNPs (rs1155563) were found to be significantly associated with 25(OH)D serum levels only in people of Arab origin. Across all three ethnicities none of the SNPs of DHCR7/NADSYN1 were associated with serum 25(OH)D levels and none of the 18 SNPs were significantly associated with serum 25(OH)D levels in people from South East Asia.

Conclusion

Our data show for the first time significant association between the GC (rs2282679 and rs7041), CYP2R1 (rs10741657) SNPs and 25(OH)D levels. This supports their roles in vitamin D Insufficiency in Arab and South Asian populations respectively. Interestingly, two of the CYP2R1 SNPs (rs10500804 and rs12794714) and one GC SNP (rs1155563) were found to correlate with vitamin D in Arab population exclusively signifying their importance in this population.     

福建绞股蓝真菌转化及其产物抗癌活性研究

研究黑曲霉和构巢曲霉两种真菌对福建绞股蓝皂苷的微生物转化。在37 ℃条件下液体发酵2 d后,HPLC分析表明,微生物转化后成分发生明显变化;利用MTT法测定抗癌活性,比较绞股蓝皂苷微生物转化前后活性变化,结果表明,转化前绞股蓝皂苷转化底物无抗癌活性,两种真菌转化产物有显著的抗癌活性。构巢曲霉和黑曲霉的转化产物对肝癌细胞SMCC7721增殖的72 h半抑制率IC₅₀值分别为92.00、40.60 mg·mL^-1;对肝癌细胞Bel7402增殖的72 h半抑制率IC50值分别为49.06、125.38 mg·mL^-1。说明两种真菌对绞股蓝皂苷微生物转化产生具有抗癌活性的成分,为从绞股蓝中筛选和分离活性成分提供新的研究思路。     

Membrane actions of vitamin D metabolites 1alpha,25(OH)2D3 and 24R,25(OH)2D3 are retained in growth plate cartilage cells from vitamin D receptor knockout mice

1alpha,25(OH)(2)D(3) regulates rat growth plate chondrocytes via nuclear vitamin D receptor (1,25-nVDR) and membrane VDR (1,25-mVDR) mechanisms. To assess the relationship between the receptors, we examined the membrane response to 1alpha,25(OH)(2)D(3) in costochondral cartilage cells from wild type VDR(+/+) and VDR(-/-) mice, the latter lacking the 1,25-nVDR and exhibiting type II rickets and alopecia. Methods were developed for isolation and culture of cells from the resting zone (RC) and growth zone (GC, prehypertrophic and upper hypertrophic zones) of the costochondral cartilages from wild type and homozygous knockout mice. 1alpha,25(OH)(2)D(3) had no effect on [(3)H]-thymidine incorporation in VDR(-/-) GC cells, but it increased [(3)H]-thymidine incorporation in VDR(+/+) cells. Proteoglycan production was increased in cultures of both VDR(-/-) and VDR(+/+) cells, based on [(35)S]-sulfate incorporation. These effects were partially blocked by chelerythrine, which is a specific inhibitor of protein kinase C (PKC), indicating that PKC-signaling was involved. 1alpha,25(OH)(2)D(3) caused a 10-fold increase in PKC specific activity in VDR(-/-), and VDR(+/+) GC cells as early as 1 min, supporting this hypothesis. In contrast, 1alpha,25(OH)(2)D(3) had no effect on PKC activity in RC cells isolated from VDR(-/-) or VDR(+/+) mice and neither 1beta,25(OH)(2)D(3) nor 24R,25(OH)(2)D(3) affected PKC in GC cells from these mice. Phospholipase C (PLC) activity was also increased within 1 min in GC chondrocyte cultures treated with 1alpha,25(OH)(2)D(3). As noted previously for rat growth plate chondrocytes, 1alpha,25(OH)(2)D(3) mediated its increases in PKC and PLC activities in the VDR(-/-) GC cells through activation of phospholipase A(2) (PLA(2)). These responses to 1alpha,25(OH)(2)D(3) were blocked by antibodies to 1,25-MARRS, which is a [(3)H]-1,25(OH)(2)D(3) binding protein identified in chick enterocytes. 24R,25(OH)(2)D(3) regulated PKC in VDR(-/-) and VDR(+/+) RC cells. Wild type RC cells responded to 24R,25(OH)(2)D(3) with an increase in PKC, whereas treatment of RC cells from mice lacking a functional 1,25-nVDR caused a time-dependent decrease in PKC between 6 and 9 min. 24R,25(OH)(2)D(3) dependent PKC was mediated by phospholipase D, but not by PLC, as noted previously for rat RC cells treated with 24R,25(OH)(2)D(3). These results provide definitive evidence that there are two distinct receptors to 1alpha,25(OH)(2)D(3). 1alpha,25(OH)(2)D(3)-dependent regulation of DNA synthesis in GC cells requires the 1,25-nVDR, although other physiological responses to the vitamin D metabolite, such as proteoglycan sulfation, involve regulation via the 1,25-mVDR.     

Cyclin D1 Serves as a Poor Prognostic Biomarker in Stage I Gastric Cancer

TNM stage still serves as the best prognostic marker in gastric cancer (GC). The next step is to find prognostic biomarkers that detect subgroups with different prognoses in the same TNM stage. In this study, the expression levels of epidermal growth factor receptor (EGFR) and cyclin D1 were assessed in 96 tissue samples, including non-tumorous tissue, adenoma, and carcinoma. Then, the prognostic impact of EGFR and cyclin D1 was retrospectively investigated in 316 patients who underwent R0 resection for GC. EGFR positivity increased as gastric tissue became malignant, and cyclin D1 positivity was increased in all the tumorous tissues. However, there was no survival difference caused by the EGFR positivity, while the cyclin D1-postive group had worse overall survival (OS) than the cyclin D1-negative group in stage I GC (10-year survival rate (10-YSR): 62.8% vs. 86.5%, p = 0.010). In subgroup analyses for the propensity score-matched (PSM) cohort, there were also significant differences in the OS according to the cyclin D1 positivity in stage I GC but not in stage II and III GC. Upon multivariate analysis, cyclin D1 positivity was an independent prognostic factor in stage I GC. In conclusion, cyclin D1 may be a useful biomarker for predicting prognosis in stage I GC.     

Monoclonal antibodies directed against gonococcal protein I vary in bactericidal activity

Monoclonal antibodies (Mab) with specificity for protein I (PI) from Neisseria gonorrhoeae (GC) were examined for bactericidal activity. Mab 4G5 (gamma 3), ID3 (gamma 2a), and 1G6 (gamma 2a) bound to surface-exposed epitopes on PI of GC strain R11 (IA serotype) as assessed by co-agglutination and 125I protein A uptake. Mab 2H1 (gamma 3) that were directed against IB serotype strains and Mab 2E9 (gamma 2a) were negative in co-agglutination and protein A uptake assays and served as controls for some experiments. Only 4G5 and 1D3 were bactericidal for R11 when presensitized organisms were incubated in 10% absorbed, pooled normal human serum (PNHS) or 10% hypogammaglobulinemic serum (H gamma S) despite binding of nearly equivalent numbers of 4G5, 1D3, and 1G6 to R11 during presensitization, as assessed by 125I-protein A uptake. These Mab activated complement to a similar extent on GC R11, leading to deposition of 56.4 X 10(3), 61.9 X 1093), and 47.1 X 10(3) molecules of C3/organism during incubation in 10% C8-deficient serum. Deposition occurred almost exclusively via the classical complement pathway. Measurement of complement component C9 binding to R11 during incubation in H gamma S showed 35,700 molecules of C9/organism with 4G5, 32,600 C9/organism with 1D3, and surprisingly, 29,600 C9/organism with 1G6. Eight thousand four hundred molecules of C9/organism bound to 2E9-coated organisms, 6000 C9/organism to 2H1-coated bacteria, and 3600 C9/organism to nonpresensitized organisms. The C5b-9 complex deposited by 4G5 had a different sedimentation profile by sucrose density gradient analysis from the C5b-9 complex deposited by 1G6, consistent with a different molecular configuration of the bound complex. Mab 1G6 and 1D3, but not 2E9 or 2H1, were able to compete with 125I-4G5 for binding to GC R11. A Mab (2E6) directed against protein III of GC competed weakly with 125I-4G5 for binding to GC R11. Mab 1G6, but not 1D3, blocked 4G5-dependent killing in a dose-related fashion. Both 4G5 and IG6 reacted weakly with native PI of GC R11 by immunoblotting, but neither Mab recognized the 34,800 m.w. fragment of PI generated by trypsin and chymotrypsin treatment of outer membranes. In contrast, 2E9 reacted strongly by immunoblot with both native and cleaved PI of GC R11, suggesting binding to buried determinants of PI. These experiments show that Mab directed against identical or closely associated, surface-exposed epitopes on gonococcal PI differ markedly in bactericidal activity, despite leading to deposition of nearly equivalent numbers of C3 and C9 molecules per organism.     

Flanking sequence effects within the pyrimidine triple-helix motif characterized by affinity cleaving.

Nearest neighbor interactions affect the stabilities of triple-helical complexes. Within a pyrimidine triple-helical motif, the relative stabilities of natural base triplets T.AT, C + GC, and G.TA, as well as triplets, D3.TA and D3.CG, containing the nonnatural deoxyribonucleoside 1-(2-deoxy-beta-D-ribofuranosyl)-4-(3-benzamido)phenylimidazole (D3) were characterized by the affinity cleaving method in the context of different flanking triplets (T.AT, T.AT: T.AT, C + GC: C + GC, T.AT: G + GC, C + GC). The to be insensitive to substitutions in either the 3' or 5' directions, while the relative stabilities of triple helices containing C + GC triplets decreased as the number of adjacent C + GC triplets increased. Triple helices incorporating a G.TA interaction were most stable when this triplet was flanked by two T.AT triplets and were adversely affected when a C + GC triplet was placed in the adjacent 5' direction. Similarly, complexes containing D3.TA or D3.CG triplets were most stable when the triplet was flanked by two T.AT triplets but were destabilized when the adjacent 3' neighbor position was occupied with a C + GC triplet. This information regarding sequence composition effects in triple-helix formation establishes a set of guidelines for targeting sequences of double-helical DNA by the pyrimidine triple-helix motif.     

Comprehensive association analysis of nine candidate genes with serum 25-hydroxy vitamin D levels among healthy Caucasian subjects

Vitamin D deficiency is a common public health problem in the US. It is related to the high risk of rickets, osteoporosis and other diseases. Currently, serum 25-hydroxy vitamin D [25(OH)D] concentration is the best indicator of vitamin D status, and determination of its deficiency or sufficiency. This level has high heritability (28–80%). However, genes contributing to the wide variation in serum 25(OH)D are generally unknown. In this study, we screened nine important genes in vitamin D metabolic pathways using 49 single nucleotide polymorphism (SNP) markers in a group of 156 unrelated healthy Caucasian subjects. Significant confounding factors that may affect serum 25(OH)D variations were used as covariates for the association analyses. An association test for quantitative trait was performed to evaluate the association between candidate genes and serum 25(OH)D levels. Permutation was conducted for correcting multiple testing problems. Evidence of association was observed at SNPs in the CYP2R1 (cytochrome P450, family 2, subfamily R, polypeptide 1) and the GC (vitamin D binding protein) gene. Next, we performed a replication study for six promising SNPs in the gene CYP2R1 and GC, using another group of 340 unrelated healthy Caucasian subjects. Association analyses were conducted in the replication cohort (n = 340) and the pooled cohort (n = 496). The CYP2R1 gene and the GC gene remain significant in the pooled cohort. The results suggest that the CYP2R1 and GC genes may contribute to the variation of serum 25(OH)D levels in healthy populations.     

Substrate Compositional Variation with Tissue/Region and Gba1 Mutations in Mouse Models–Implications for Gaucher Disease

Gaucher disease results from GBA1 mutations that lead to defective acid β-glucosidase (GCase) mediated cleavage of glucosylceramide (GC) and glucosylsphingosine as well as heterogeneous manifestations in the viscera and CNS. The mutation, tissue, and age-dependent accumulations of different GC species were characterized in mice with Gba1 missense mutations alone or in combination with isolated saposin C deficiency (C*). Gba1 heteroallelism for D409V and null alleles (9V/null) led to GC excesses primarily in the visceral tissues with preferential accumulations of lung GC24∶0, but not in liver, spleen, or brain. Age-dependent increases of different GC species were observed. The combined saposin C deficiency (C*) with V394L homozygosity (4L;C*) showed major GC18∶0 degradation defects in the brain, whereas the analogous mice with D409H homozygosity and C* (9H;C*) led to all GC species accumulating in visceral tissues. Glucosylsphingosine was poorly degraded in brain by V394L and D409H GCases and in visceral tissues by D409V GCase. The neonatal lethal N370S/N370S genotype had insignificant substrate accumulations in any tissue. These results demonstrate age, organ, and mutation-specific quantitative differences in GC species and glucosylsphingosine accumulations that can have influence in the tissue/regional expression of Gaucher disease phenotypes.     

MicroRNA-135b/CAMK2D Axis Contribute to Malignant Progression of Gastric Cancer through EMT Process Remodeling

There is a continued need for investigating the roles of microRNAs (miRNAs) and their targets on the progression of gastric cancer (GC), especially metastasis. Here, we performed an integrated study to identify dysregulated miRNAs critical for GC development and progression. miR-135b was determined as a promising biomarker for GC. The expression level of miR-135b was increased among GC cell lines, patient tumor tissues, serum samples, and correlation with aggravation of the GC patients. The in vitro functional assays demonstrated overexpression of miR-135b promoted cell proliferation, migration and invasion in GC, while miR-135b inhibition led to the opposite results. CAMK2D was found to be the direct target of miR-135b, serving as a tumor suppressor in GC cells. Based on our and public datasets, we confirmed the attenuation of CAMK2D expression in GC tissues. And, the expression levels of miR-135b and CAMK2D were closely associated with prognosis of GC patients. Ectopic expression of miR-135b resulted in the down-regulation of CAMK2D. Additionally, CAMK2D was a prerequisite for miR-135b to promote GC cells proliferation and migration by regulating the EMT process, which was confirmed by the in vivo experiments. Importantly, in vivo injection of miR-135b antagomir significantly repressed the tumor growth and metastasis of xenograft models, which suggested that the miR-135b antagomir were promising for clinical applications. Taken together, these results indicate that miR-135b/CAMK2D axis drives GC progression by EMT process remodeling, suggesting that miR-135b may be utilized as a new therapeutic target and prognostic marker for GC patients.     

1,25-Dihydroxycholecalciferol and glucocorticosteroid regulation of adenylate cyclase in an osteoblast-like cell line

To study regulation of the parathyroid hormone (PTH)-responsive adenylate cyclase of osteoblast-like cells by 1,25-dihydroxyvitamin D (1,25(OH)2D), cAMP levels and adenylate cyclase activity were assayed in the hormone-responsive ROS 17/2.8 rat osteosarcoma cell line. Treatment of cells with 1,25(OH)2D3: alone markedly attenuated the cAMP response to subsequent PTH; decreased adenylate cyclase stimulated by PTH; and completely antagonized the positive regulatory effects of cell treatment with glucocorticosteroid (GC) on these responses to PTH. Sterol receptor mediation was indicated by specificity for the 1,25(OH)2D metabolite and high sensitivity (half-maximal attenuation at 7 X 10(-11) M). The effects of 1,25(OH)2D and GC were primarily on the maximal activity of adenylate cyclase and not on sensitivity to Mg2+, guanine nucleotide, or PTH. GC augmentation of ROS 17/2.8 cell cAMP accumulation was also seen with another receptor agonist (beta-adrenergic), cholera toxin or forskolin; 1,25(OH)2D antagonized all these GC effects. Opposing effects of GC and 1,25(OH)2D were seen as well on activation of the guanine nucleotide-binding regulatory protein (Ns) by guanyl-5'-yl imidodiphosphate and F- and on activation of the catalyst (C) by Mn2+. In contrast, with the activators other than PTH, cell treatment with 1,25(OH)2D in the absence of GC produced only minor attenuation of cAMP accumulation and no effect on adenylate cyclase activities. The data suggest that GC acts strongly on or near the PTH receptor-Ns complex in ROS 17/2.8 and to a lesser degree on the Ns-C interaction. Direct GC enhancement of C could not be concluded because of the influence of Ns on forskolin action and present data that Mn2+ does not uncouple Ns from C in this system. A GC effect on membrane structure or composition, as seen in other cell types, could explain these changes in adenylate cyclase function without the need to postulate multiple mechanisms. The data dissociate two 1,25(OH)2D effects, direct attenuation of activation of Ns via the PTH receptor and interference with the as yet undefined mechanism(s) of GC augmentation. These may represent dissimilar pathways of 1,25(OH)2D action on osteoblasts.     

Vitamin D3 metabolites regulate LTBP1 and latent TGF-beta1 expression and latent TGF-beta1 incorporation in the extracellular matrix of chondrocytes

Growth plate chondrocytes make TGF-beta1 in latent form (LTGF-beta1) and store it in the extracellular matrix via LTGF-beta1 binding protein (LTBP1). 1,25-(OH)2D3 (1,25) regulates matrix protein production in growth zone (GC) chondrocyte cultures, whereas 24,25-(OH)2D3 (24,25) does so in resting zone (RC) cell cultures. The aim of this study was to determine if 24,25 and 1,25 regulate LTBP1 expression as well as the LTBP1 -mediated storage of TGF-beta1 in the extracellular matrix of RC and GC cells. Expression of LTBP1 and TGF-beta1 in the growth plate and in cultured RC and GC cells was determined by in situ hybridization using sense and antisense oligonucleotide probes based on the published rat LTBP1 and TGF-beta1 cDNA sequences. Fourth passage male rat costochondral RC and GC chondrocytes were treated for 24 h with 10(-7)-10(-9) M 24,25 and 10(-8)-10(-10) M 1,25, respectively. LTBP1 and TGF-beta1 mRNA levels were measured by in situ hybridization; production of LTGF-beta1, LTGF-beta2, and LTBP1 protein in the conditioned media was verified by immunoassays of FPLC-purified fractions. In addition, ELISA assays were used to measure the effect of 1,25 and 24,25 on the level of TGF-beta1 in the media and matrix of the cultures. Matrix-bound LTGF-beta1 was released by digesting isolated matrices with 1 U/ml plasmin for 3 h at 37 degrees C. LTBP1 and TGF-beta1 mRNAs are co-expressed throughout the growth plate, except in the lower hypertrophic area. Cultured GC cells express more LTBP1 and TGF-beta1 mRNAs than RC cells. FPLC purification of the conditioned media confirmed that RC cells produce LTGF-beta1, LTGF-beta2, and LTBP1. GC cells also produce LTGF-beta2, but at lower concentrations. 1,25 dose-dependently increased the number of GC cells with high LTBP1 expression, as seen by in situ hybridization. 24,25 had a similar, but less pronounced, effect on RC cells. 1,25 also caused a dose-dependent increase in the amount of TGF-beta1 protein found in the matrix, significant at 10(-8) and 10(-9) M, and a corresponding decrease in TGF-beta1 in the media. 24,25 had no effect on the level of TGF-beta1 in the matrix or media produced by RC cells. This indicates that 1,25 induces the production of LTBP1 by GC cells and suggests that the TGF-beta1 content of the media is reduced through the formation of latent TGF-beta1 -LTBP1 complexes which mediates storage in the matrix. Although 24,25 induced the expression of LTBP1 by RCs, TGF-beta1 incorporation into the matrix is not regulated by this vitamin D3 metabolite. Thus, vitamin D3 metabolites may play a role in regulating the availability of TGF-beta1 by modulating LTBP1 production.     

Chemical Diversity of Essential Oils from Asteriscus graveolens (Forssk.) Less.: Identification of cis‐8‐Acetoxychrysanthenyl Acetate as a New Natural Component

Asteriscus graveolens is an endemic medicinal plant mainly distributed in south‐western Algeria and south‐eastern Morocco. The essential oils of leaves, stems, and flowers of A. graveolens had been studied by GC, GC/MS, and ¹³C‐NMR. The spectral data of two nerolidol derivatives, 6‐oxo‐ and 6‐hydroxycyclonerolidol, were reassigned by 1D‐ and 2D‐NMR spectroscopy. These compounds can be considered as chemical markers of this genus. The structure of a monoterpenic diester with a chrysanthenane skeleton, i.e., cis‐8‐acetoxychrysanthenyl acetate, was determined for the first time on the basis of GC/MS, and 1D‐ and 2D‐NMR. The stem and leaf oils were characterized by high content of oxygenated sesquiterpenes with 6‐oxo‐ and 6‐hydroxycyclonerolidol as major components, and the flower essential oils were dominated by the new monoterpenic compound cis‐8‐acetoxychrysanthenyl acetate.     

METTL16 promotes cell proliferation by up-regulating cyclin D1 expression in gastric cancer

N6-methyladenosine (m6A) is a well-known modification of RNA. However, as a key m6A methyltransferase, METTL16 has not been thoroughly studied in gastric cancer (GC). Here, the biological role of METTL16 in GC and its underlying mechanism was studied. Immunohistochemistry was used to detect the expression of METTL16 and relationship between METTL16 level and prognosis of GC was analysed. CCK8, colony formation assay, EdU assay and xenograft mouse model were used to study the effect of METTL16. Regulatory mechanism of METTL16 in the progression of GC was studied through flow cytometry analysis, RNA degradation assay, methyltransferase inhibition assay, RT-qPCR and Western blotting. METTL16 was highly expressed in GC cells and tissues and was associated with prognosis. In vitro and in vivo experiments confirmed that METTL16 promoted proliferation of GC cells and tumour growth. Furthermore, down-regulation of METTL16 inhibited proliferation by G1/S blocking. Significantly, we identified cyclin D1 as a downstream effector of METTL16. Knock-down METTL16 decreased the overall level of m6A and the stability of cyclin D1 mRNA in GC cells. Meanwhile, inhibition of methyltransferase activity reduced the level of cyclin D1. METTL16-mediated m6A methylation promotes proliferation of GC cells through enhancing cyclin D1 expression.