Integration of covalent organic frameworks and molecularly imprinted polymers for selective extraction of flavonoid naringenin from grapefruit (Citrus × paradisi Macf.) peels

Grapefruit (Citrus × paradisi Macf.) peel, a by-product of the citrus-processing industry, possesses an important economic value due to the richness of bioactive compounds. In this study, boron-linked covalent organic frameworks integrated with molecularly imprinted polymers (CMIPs) were developed via a facile one-pot bulk polymerization approach for the selective extraction of naringenin from grapefruit peel extract. The obtained CMIPs possessed a three-dimensional network structure with uniform pore size distribution, large surface areas (476 m2/g), and high crystallinity. Benefiting from the hybrid functional monomer APTES-MAA, the acylamino group can coordinate with the boronate ligands of the boroxine-based framework to form B-N bands, facilitating the integration of imprinted cavities with the aromatic skeleton. The composite materials exhibited a high adsorption capacity of 153.65 mg/g, and a short adsorption equilibrium time of 30 min for naringenin, together with favorable selectivity towards other flavonoid analogues. Additionally, the CMIPs captured the template molecules through π-π* interaction and hydrogen bonding, as verified by FT-IR and XPS. Furthermore, they had good performance when employed to enrich naringenin in grapefruit peels extract compared with the common adsorbent materials including AB-8, D101, cationic exchange resin, and active carbon. This research highlights the potential of CMIPs composite materials as a promising alternative adsorbent for naringenin extraction from grapefruit peel.

Octanal enhances disease resistance in postharvest citrus fruit by the biosynthesis and metabolism of aromatic amino acids

Octanal was found to be able to reduce green mold incidence in citrus fruit by a defense response mechanism. However, the underlying mechanism remains largely unclear. Herein, the metabolomics, RNA-seq and biochemical analyses were integrated to explore the effect of octanal on disease resistance in harvested citrus fruit. Results showed that octanal fumigation at 40 μL L-1 was effective in controlling citrus green mold. Metabolomics analysis showed that octanal mainly led to the accumulation of some plant hormones including methyl jasmonate, abscisic acid, indole-3-butyric acid, indoleacetic acid (IAA), salicylic acid, and gibberellic acid and many phenylpropanoid metabolites including cinnamyl alcohol, hesperidin, dihydrokaempferol, vanillin, quercetin-3-O-malonylglucoside, curcumin, naringin, chrysin, coniferin, calycosin-7-O-β-D-glucoside, trans-cinnamaldehyde, and 4',5,7-trihydroxy-3,6-dimethoxyflavone. Particularly, IAA and hesperidin were dramatically accumulated in the peel, which might be the contributors to the resistance response. Additionally, transcriptome analysis showed that octanal greatly activated the biosynthesis and metabolism of aromatic amino acids. This was further verified by the accumulation of some metabolites (shikimic acid, tryptophan, tyrosine, phenylalanine, IAA, total phenolics, flavonoids and lignin), increase in some enzyme activities (phenylalanine ammonia-lyase, tyrosine ammonia-lyase, 4-coumarate CoA ligase, cinnamic acid 4-hydroxylase, polyphenol oxidase, and peroxidase), up-regulation of some genes (tryptophan pyruvate aminotransferase, aldehyde dehydrogenase, shikimate kinase and shikimate dehydrogenase) expressions and molecular docking results. Thus, these results indicate that octanal is an efficient strategy for the control of postharvest green mold by triggering the defense response in citrus fruit.

Inhibitory Mechanisms of trans-2-Hexenal on the Growth of Geotrichum citri-aurantii

Geotrichum citri-aurantii (G. citri-aurantii) is one of the most important postharvest pathogens leading to a postharvest loss of citrus by causing sour rot. In this study, the antifungal activity of trans-2-hexenal, a natural component of essential oil, against G. citri-aurantii was evaluated. Trans-2-hexenal treatment inhibited the mycelia growth of G. citri-aurantii with a minimum inhibitory concentration and minimum fungicidal concentration of trans-2-hexenal at 0.50 and 1.00 μL/mL, respectively. Moreover, trans-2-hexenal efficiently reduced the incidence of sour rot of Satsuma fruit inoculated with G. citri-aurantii. Ultrastructural observations and Fourier transform infrared (FT-IR) results showed that trans-2-hexenal treatment affected the cell wall and cell membrane instructions of G. citri-aurantii. The content of β-1,3-glucan was significantly decreased after trans-2-hexenal treatment, but the cell wall permeability was not changed. The decrease in lipid and ergosterol contents might be responsible for this antifungal activity. Several important genes, FKS1, ERG1, ERG7, and ERG11, showed decreasing expression levels after trans-2-hexenal treatment. Molecule-docking results also indicated that trans-2-hexenal could join with the protein of FKS1, ERG1, ERG7, and ERG11 to impact enzyme activities. These results demonstrated that trans-2-hexenal is a promising fungicide for controlling sour rot of harvested citrus fruit by damaging the membrane integrity of G. citri-aurantii.

γ-Cyclodextrin encapsulated thymol for citrus preservation and its possible mechanism against Penicillium digitatum

The volatility of essential oils greatly limits their industrial applications. Here, we successfully prepared γ-cyclodextrin (γ-CD) inclusion compounds (γ-CDTL) containing thymol (TL) for the control of green mold caused by Penicillium digitatum (P. digitatum) in citrus fruit. In vitro experiment showed that the minimum fungicidal concentration (MFC) of γ-CDTL against the hyphae growth of P. digitatum was 2.0 g/L, and 8 × MFC treatment significantly reduced the occurrence of green mold in citrus fruit and had no adverse effect on fruit quality in vivo test compared to prochloraz. Scanning electron microscopy (SEM), x-ray diffraction (XRD), fourier transform-infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), physical properties and sustained release properties were also performed, results indicated that the hydrogen bonds between TL and γ-CD were the basis for the formation of γ-CDTL. We further investigated the inhibition mechanism of γ-CDTL. SEM and TEM experiments showed that γ-CDTL treatment caused severe damage to the hyphal morphology and cells in 30 min and disrupted the permeability of P. digitatum mycelial cell walls by increasing the chitinase activity, thus accelerating the leakage of intracellular lysates. However, the integrity of the cell membrane was obviously damaged only after 60 min of treatment. In conclusion, we prepared a novel inclusion complex γ-CDTL with obvious antifungal effects and preliminarily elucidated its inclusion mechanism and antifungal mechanism. γ-CDTL might be a potent alternative to chemical fungicides for controlling the postharvest decay of citrus.

Integrated transcriptomic-metabolomic analysis reveals that cinnamaldehyde exposure positively regulates the phenylpropanoid pathway in postharvest Satsuma mandarin (Citrus unshiu)

Previously, wax + cinnamaldehyde (WCA) was proven to be able to effectively alleviate fruit decay and induce resistance in harvested Satsuma mandarin (Citrus unshiu). However, the potential molecular mechanism is largely unknown. In the present study, transcriptomics, metabolomics and biochemical analyses were combined to clarify this process. Transcriptomic analysis revealed that the expression of genes involved in secondary metabolites and related to pathogenesis and the phenylpropanoid pathway were significantly influenced by WCA treatment. In addition, metabolite profiling revealed that metabolites in the phenylpropanoid pathway were also predominantly impacted after WCA treatment. Correspondingly, enzymatic activities and gene expression involved in the phenylpropanoid pathway were positively regulated, especially in the first 24 h, resulting in increased levels of total phenolics, flavonoids and other secondary metabolites. Fruit inoculation experiments showed that WCA treatment significantly reduced the development of citrus green mold and sour rot while having no adverse effects on the edible quality of the tested citrus fruit. Our study confirms the potential role of WCA exposure in citrus to induce resistance through the phenylpropanoid pathway.

Screening of Oxygenated Aromatic Compounds for Potential Antifungal Activity against Geotrichum citri-aurantii through Structure-Activity Relationship Analysis

Sour rot caused by Geotrichum citri-aurantii (G. citri-aurantii) is responsible for huge economic losses during citrus fruit storage. However, the availability of chemical fungicides for controlling this disease is rather limited. In the present study, the antifungal activities of 25 oxygenated aromatic compounds against the mycelial growth of G. citri-aurantii were determined, and their corresponding structure-activity relationships were illustrated. Salicylaldehyde (pMIC = 2.689) possessed the strongest inhibitory effect on G. citri-aurantii growth, followed by thymol (pMIC = 2.478) and o-phthalaldehyde (pMIC = 2.429). Molecular electrostatic potential and molecular orbital analysis showed that the antifungal efficiency of test compounds was determined by the number and location of hydroxyl and aldehyde groups and the length of the ester chain. All compounds were selected for quantitative structure-antifungal activity relationship (QSAR) analysis. A three-dimensional-QSAR model of G. citri-aurantii inhibitors was established and demonstrated good predictive capability [comparative molecular field analysis, q² = 0.532, optimum number of components (ONC) =10, R² = 0.996, F = 560.325, standard error of estimation (SEE) = 0.034, and two descriptors; comparative similarity index analysis, q² = 0.675, ONC = 6, R² = 0.989, F = 263.354, SEE = 0.054, and five descriptors]. QSAR analysis showed that substitution at position 1 with hydrophilic and electron-withdrawing groups produced a hydrogen donor and thus improved the antifungal activity. In contrast, substitution at positions 4 or 5 with hydrophilic and electron-donating groups decreased its antifungal activity. These findings can provide theoretical guidance for preparing effective antifungal drugs for controlling sour rot in citrus.

A combination of cinnamaldehyde and citral greatly alleviates postharvest occurrence of sour rot in citrus fruits without compromising the fruit quality

One of the most troublesome postharvest diseases of citrus fruits is sour rot, caused by Geotrichum citri-aurantii. Sour rot reduces the shelf life of the fruits leading to massive economic losses. This study investigated the potential for a combination of cinnamaldehyde and citral (CC; 1: 2, v/v) at reducing the incidence of sour rot postharvest and its possible effect on fruit quality. Our findings show that CC could totally inhibit germination of G. citri-aurantii spores, with the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) both being 0.80 mL L^-1. The combination (CC) acted against G. citri-aurantii by targeting the chitin content of the cell wall. Wax + CC (WCC; 1 × MFC) treatment also showed high efficiency in reducing the incidence of sour rot, which was 40% lower than in the control group by day 8 when all the fruits in the latter were rotten. Apart from vitamin c (Vc) content which was higher in the test group than in the control group, WCC treatment did not have any significant effect on the quality of the citrus fruits, the examined fruit quality parameters being weight loss rate, coloration index, firmness, pH, total soluble solid (TSS) content, Vc content, as well as solid acid ratio. These results indicate that the combination of cinnamaldehyde and citral (CC, 1: 2, v/v) can be used as a natural preservative to alleviate the progress of sour rot in citrus fruits postharvest.

MiR-155-5p affects Wilms' tumor cell proliferation and apoptosis via targeting CREB1

The article "MiR-155-5p affects Wilms' tumor cell proliferation and apoptosis via targeting CREB1", by X.-S. Zhao, B. Han, J.-X. Zhao, N. Tao, C.-Y. Dong, published in Eur Rev Med Pharmacol Sci 2019; 23 (3): 1030-1037-DOI: 10.26355/eurrev_201902_16990-PMID: 30779069, has been retracted by the authors due to a slight deviation in the data. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/16990.

Long noncoding RNA MIAT acts as an oncogene in Wilms' tumor through regulation of DGCR8

The article "Long noncoding RNA MIAT acts as an oncogene in Wilms' tumor through regulation of DGCR8, by X.-S. Zhao, N. Tao, C. Zhang, C.-M. Gong, C.-Y. Dong, published in Eur Rev Med Pharmacol Sci 2019; 23 (23): 10257-10263-DOI: 10.26355/eurrev_201912_19663-PMID: 31841180" has been withdrawn from the authors due to inaccuracies in the data. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/19663#:~:text=CONCLUSIONS%3A%20The%20above%20results%20suggested,and%20therapy%20of%20Wilms'%20tumor.

Cinnamaldehyde promotes the defense response in postharvest citrus fruit inoculated with Penicillium digitatum and Geotrichum citri-aurantii

Induced resistance in harvested fruit and vegetables is a superior strategy to reduce postharvest decay. In the present study, Cinnamaldehyde (CA) was applied to investigate for its induced resistance against Penicillium digitatum and Geotrichum citri-aurantii. The results showed that 5250 mg CA/L wax was effective concentration in inducing the resistance of citrus fruit to green mold and sour rot. Wax+ CA (WCA) reduced significantly green mold and sour rot incidences at different exposure times, with 24 h being the optimal exposure time. The host reactions under infection with different pathogens were similar. During initial exposure, treatment with 5250 mg CA/L wax enhanced significantly the activities of phenylalanine ammonia-lyase (PAL), peroxidase (POD), polyphenol oxidase (PPO), β-1, 3-glucanase (GLU) and chitinase (CHT) in the presence of direct contact with the pathogen. Simultaneously, WCA induced an increase in total phenolic, flavanone and dihydroflavonol, flavone and flavonol, and lignin contents. Thus, our results suggest that treatment using 5250 mg CA/L wax can be applied early to control diseases by provoking response reactions in citrus fruit.

Citronellal Exerts Its Antifungal Activity by Targeting Ergosterol Biosynthesis in Penicillium digitatum

Ergosterol (ERG) is a potential target for the development of antifungal agents against Penicillium digitatum, the pathogen of green mold in citrus fruits. This study examined the mechanism by which citronellal, a typical terpenoid of Cymbopogon nardus essential oil, acts on ergosterol to exhibit its antifungal activity against P. digitatum. We previously reported that citronellal inhibited the growth of P. digitatum with minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of 1.36 and 2.72 mg/mL, respectively. In citronellal-treated cells, the membrane integrity and ergosterol contents significantly decreased, whereas lanosterol, which serves as a precursor for ergosterol biosynthesis, massively accumulated. Addition of 150 mg/L of exogenous ergosterol decreased the inhibitory rate of citronellal, restoring the ergosterol content and hence the membrane structure to normal levels, and triggered expression of nearly all ERG genes. Based on our findings, we deduce that citronellal damages the cell membrane integrity of P. digitatum by down-regulating the ERG genes responsible for conversion of lanosterol to ergosterol, the key downregulated gene being ERG3, due to the observed accumulation of ergosta-7,22-dienol.

Antofine inhibits postharvest green mold due to imazalil-resistant Penicillium digitatum strain Pdw03 by triggering oxidative burst

The emergence of imazalil (IMZ) resistance in Penicillium digitatum has become a great threat for controlling citrus green mold. In this paper, we investigated the antifungal efficiency and mechanism of an alkaloid antofine against an IMZ-resistant P. digitatum strain Pdw03. Results showed that antofine exhibited a strong antifungal activity against the mycelial growth of strain Pdw03, with a minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) of 1.56 × 10^-3 and 1.25 × 10^-2  g/L, respectively. In vivo application of antofine effectively delayed the disease progress and reduced the incidence of green mold in citrus fruit. The disease incidence of 10 × MFC antofine-treated fruit after 6 days of storage was only 11% ± 4%, which was significantly lower than that of the control (100% ± 0%). Antofine treatment altered mycelial morphology of strain Pdw03 without affecting the cell wall integrity. Although the ergosterol contents remained stable, a decrease in the total lipid content induced by lipid peroxidation was observed at 30 min of exposure, indicating disruption of cell membrane permeability of strain Pdw03. In addition, the mitochondrial membrane potential (MMP) and adenosine triphosphate (ATP) contents were also decreased at 60 min of exposure. These results indicated that antofine inhibited the growth of strain Pdw03 by disrupting cell membrane permeability and impairing energy metabolism induced by oxidative burst. PRACTICAL APPLICATIONS: One of the most economically important postharvest diseases of citrus fruit is green mold caused by Penicillium digitatum. The pathogen is mainly controlled by using imazalil, but the prolonged and extensive application of this chemical fungicide has led to emergence of numerous IMZ-resistant strains among P. digitatum isolates. Consequently, new and safe strategies for controlling citrus green mold caused by IMZ-resistant P. digitatum strains are urgently needed. In this study, an alkaloid antofine effectively inhibited the growth of IMZ-resistant P. digitatum strain Pdw03 and significantly decreased green mold incidence in the affected citrus fruits. Antofine induced membrane lipid peroxidation of Pdw03 mycelia, resulting in damage to the cell membrane and impairment of energy metabolism. Antofine is therefore a potential antifungal agent for the control of green mold, which provide theoretical guidance for the food industry.

Long noncoding RNA MIAT acts as an oncogene in Wilms' tumor through regulation of DGCR8

OBJECTIVE

Recent researches have proved that long noncoding RNAs (lncRNAs) cover an important role in malignant tumors. Our study showed how lncRNA myocardial infarction-associated transcript (MIAT) functions in the development of Wilms' tumor.

PATIENTS AND METHODS

Real Time-quantitative Polymerase Chain Reaction (RT-qPCR) was utilized to detect the MIAT expression in Wilms' tumor patients. The MIAT expression level and the patients' overall survival time were analyzed. Then, we conducted functional experiments to identify the changes in the biological behaviors of Wilms' tumor cells due to the loss of MIAT. Moreover, further experiments were performed to explore the potential mechanism.

RESULTS

By comparing with MIAT expression in adjacent tissues, the MIAT expression level was significantly higher in Wilms' tumor samples. Moreover, the cell growth ability of Wilms' tumor cells was inhibited due to the loss of MIAT. The migrated and invaded ability of the Wilms' tumor cells was inhibited due to the loss of MIAT. Furthermore, the expression of DGCR8 was downregulated due to the loss of MIAT. In addition, it was found that the DGCR8 expression was positively correlated to MIAT expression in Wilms' tumor tissues.

CONCLUSIONS

The above results suggested that MIAT could promote the cell proliferation and the metastasis of Wilms' tumor by upregulating DGCR8, which indicated that MIAT might be a potential target for the diagnosis and therapy of Wilms' tumor.

Long noncoding RNA SNHG16 acts as an oncogene in Wilms' tumor through sponging miR-200a-3p

Since this article has been suspected of research misconduct and the corresponding authors did not respond to our request to prove originality of data and figures, "Long noncoding RNA SNHG16 acts as an oncogene in Wilms' tumor through sponging miR-200a-3p, by X.-S. Zhao, N. Tao, C. Zhang, C.-M. Gong, C.-Y. Dong, published in Eur Rev Med Pharmacol Sci 2020; 24 (8): 4145-4151-DOI: 10.26355/eurrev_202004_20994-PMID: 32373950" has been withdrawn. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/20994.

MiR-155-5p affects Wilms' tumor cell proliferation and apoptosis via targeting CREB1

OBJECTIVE

The aim of this study was to explore the role of microRNA-155-5p (miR-155-5p) in regulating the proliferation and apoptosis of Wilm's tumor (WT), and to investigate the possible underlying mechanism.

PATIENTS AND METHODS

The expression levels of miR-155-5p in 37 pairs of WT clinical samples, as well as WT cell line (G401), were detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR). MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay and flow cytometry assay were used to detect the effects of miR-155-5p on cell proliferation, cycle and apoptosis. Target gene prediction software was applied to screen the potential downstream target gene of miR-155-5p. QRT-PCR, Western blot (WB) and luciferase reporter gene assay proved that cAMP-response element binding protein 1 (CREB1) was the target gene of miR-155-5p. Besides, rescue experiment was conducted to further explore the effect of CREB1 on WT cells.

RESULTS

The expression levels of miR-155-5p in WT tissues and cells were both significantly down-regulated. Importantly, miR-155-5p was found to be involved in the malignant behavior of WT cells. MTT assay and flow cytometry assay demonstrated that miR-155-5p significantly inhibited the proliferation, caused stagnation of cells in G0/G1 phase, and promoted cell apoptosis. CREB1 was verified as a functional target gene of miR-155-5p, which was negatively regulated by miR-155-5p. Rescue experiments indicated that restoring the expression of CREB1 could interfere with the effects of miR-155-5p on WT cells.

CONCLUSIONS

MiR-155-5p could regulate the proliferation, cell cycle and apoptosis of WT cells. These effects were achieved by regulating the expression of CREB1. Furthermore, our study might provide a new theoretical basis for the basic research of WT.

p-Anisaldehyde Exerts Its Antifungal Activity Against Penicillium digitatum and Penicillium italicum by Disrupting the Cell Wall Integrity and Membrane Permeability

Penicillium digitatum and P. italicum are the two important postharvest pathogens in citrus, causing about 90% of the total loss of citrus fruit during storage and transportation. Natural fungicides such as essential oils have been widely used instead of chemical fungicides for preventing and controlling postharvest diseases. In this research, p-anisaldehyde exhibited a strong inhibitory effect on P. digitatum and P. italicum, with the minimum inhibitory concentration and minimum fungicidal concentration values of both being 2.00 μl/ml. Additionally, p-anisaldehyde visibly inhibited both the green mold and blue mold development of citrus fruits inoculated with P. digitatum and P. italicum. The mycelia morphologies of these pathogens were greatly altered, and the membrane permeability and cell wall integrity of mycelia were severely disrupted under p-anisaldehyde treatment. These results suggest that the antifungal activity of p-anisaldehyde against P. digitatum and P. italicum can be attributed to the disruption of the cell wall integrity.

Long noncoding RNA SNHG16 acts as an oncogene in Wilms' tumor through sponging miR-200a-3p

OBJECTIVE

Recently, the role of long noncoding RNA (lncRNAs) in tumor progression has attracted much attention. The aim of this study was to investigate the role of lncRNA SNHG16 in the development of Wilms' tumor, and to explore the underlying mechanism.

PATIENTS AND METHODS

Real Time-quantitative Polymerase Chain Reaction (RT-qPCR) was used to detect SNHG16 expression in Wilms' tumor patients' tissues. Function assays, including wound healing assay, and transwell assay, were conducted to detect the changes of biological behaviors in Wilms' tumor cells due to gain or loss of SNHG16. Besides, the luciferase reporter gene assay was performed to explore the underlying mechanism.

RESULTS

The expression level of SNHG16 was significantly up-regulated in Wilms' tumor tissues when compared with adjacent tissues. Cell migration and invasion abilities were significantly repressed via down-regulation of SNHG16. However, opposite results were obtained after up-regulation of SNHG16 in vitro. After the down-regulation of SNHG16, the expression of miR-200a-3p increased significantly. However, the expression of miR-200a-3p was remarkably reduced via up-regulation of SNHG16 in vitro. Furthermore, SNHG16 acted as a competing endogenous RNA via sponging miR-200a-3p in Wilms' tumor.

CONCLUSIONS

SNHG16 induced the metastasis of Wilms' tumor via sponging miR-200a-3p. Our findings might provide a new prospect for the diagnosis and therapy of Wilms' tumor.

Abstract P4-13-03: Elacestrant (RAD1901) demonstrates anti-tumor activity in models resistant to CDK4/6 inhibitors

Background: Approximately 75% of all breast cancers diagnosed are estrogen receptor-positive (ER+) and currently approved endocrine therapies rely heavily on blocking of the ER signaling pathway. In recent years, the combination of an endocrine agent with other targeted agents have been evaluated to address endocrine resistance and improve progression-free survival (PFS). Recently, it was demonstrated that the addition of a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor to an endocrine agent roughly doubles PFS, leading to the approval and use of certain CDK4/6 inhibitors in combination with either aromatase inhibitors in the first-line metastatic setting or in combination with the selective estrogen receptor degrader (SERD), fulvestrant, in the second-line metastatic setting. While combining CDK4/6 inhibitors and endocrine therapy can result in significantly increased PFS, patients eventually progressed on these combinations, and to date, there is no cure for patients with advanced metastatic ER+ breast cancer. Given the increased use of CDK4/6 inhibitors in the ER+ breast cancer treatment paradigm, it will be important to understand how treatment resistance to CDK4/6 inhibitors manifests in order to optimize therapeutic strategies to target this patient population. We have previously described elacestrant (RAD1901), a novel and orally bioavailable SERD, as an inhibitor of ER+ breast cancer growth in in vitro models and in in vivo patient-derived xenograft (PDX) models. Importantly, elacestrant inhibited the growth of PDX models that were derived from heavily pretreated patients, models harboring mutations in ESR1, and models insensitive to standard of care endocrine therapies. Given these results, we hypothesized that elacestrant would have anti-tumor activity in a CDK4/6 inhibitor-resistant setting. Herein, we describe elacestrant activity in multiple in vitro and in vivo models of CDK4/6 inhibitor resistance in both wild-type and mutant ESR1 backgrounds.

Methods: In vitro models of estrogen-independent ER+ breast cancer, harboring either wild-type or mutant ER, were exposed to increasing concentrations of approved CDK4/6 inhibitors: palbociclib, ribociclib, or abemaciclib. ER expression/signaling, changes in cell cycle mediators, and the effects of elacestrant and other SERDs were examined in these representative models.

Results: Despite prolonged exposure to CDK4/6 inhibitors, the resistant cell lines retained ER, ER signaling, and importantly, ER-driven proliferation. Elacestrant induced dose-dependent growth inhibition in CDK4/6 inhibitor-resistant cells, and this effect was independent of the CDK4/6 inhibitor used to generate resistance. Elacestrant also demonstrated in vivo tumor growth inhibition of CDK4/6 inhibitor-resistant ER+ PDX models.

Conclusions: Our preclinical data demonstrate that elacestrant is a SERD that can inhibit tumor growth in a CDK4/6 inhibitor-resistant setting and provides rationale for examining elacestrant in patients that have progressed on a combination of endocrine therapy with a CDK4/6 inhibitor.

Citation Format: Patel H, Tao N, Arlt H, Bihani T. Elacestrant (RAD1901) demonstrates anti-tumor activity in models resistant to CDK4/6 inhibitors [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-13-03.

Abstract P6-20-08: Anti-tumor activity of elacestrant (RAD1901) in models harboring ESR1 mutations resistant to standard of care therapies

Background: Estrogen receptor positive (ER+) breast cancers make up approximately 75% of all breast cancers diagnosed and ER, a protein encoded by the ESR1 gene, plays a major role in the initiation, growth and survival of these cancers. Current targeted therapies inhibit the ER pathway by either blocking the synthesis of the natural ligand of ER, estradiol, (aromatase inhibitors (AI)), or by antagonizing and/or degrading the receptor (selective estrogen receptor modulators (SERMs) and selective estrogen receptor degraders (SERDs)). AIs are used in both the adjuvant and metastatic setting and recent clinical reports have shown that 20-50% of patients that had received AI therapy had detectable mutations in the ER ligand binding domain (ER-LBD). Two frequently found point mutations in the ER-LBD, Y537S and D538G, have been shown to result in estradiol-independence and constitutive activation of ER, consistent with their ability to cause resistance to AIs. While the selection of ESR1 mutations post-AI has been demonstrated clinically, the clinical response of ESR1 mutant tumors to fulvestrant, an approved SERD, is not fully understood. Preclinical studies have suggested that ESR1 mutations can cause decreased binding and a corresponding decrease in potency of ER antagonists, including fulvestrant (SERD) and tamoxifen (SERM). Conversely, clinical data from the SoFEA, PALOMA-3, and FERGI trials suggested the presence of ESR1 mutations did not alter fulvestrant activity. The limited clinical data that exists, however, is based on retrospective study designs with relatively small data sets, making it difficult to accurately predict fulvestrant activity against specific mutations and the activity of fulvestrant against tumors that harbor multiple mutations. In fact, recent additional data from the PALOMA-3 trial suggests that the Y537S mutation, specifically, was selected out in clinical samples from patients treated with fulvestrant, more closely matching preclinical results. This suggests there may be certain contexts of ESR1 mutations where fulvestrant may have limited activity. It will be important to further understand the consequence of specific mutations and to utilize therapies that have activity against all ESR1 mutations. We have previously described elacestrant (RAD1901), a novel orally bioavailable SERD, that exhibited activity in multiple ER+ breast cancer models. Interestingly, elacestrant exhibited similar effects to fulvestrant in in vitro ESR1 mutant models, however, in some in vivo PDX models harboring the Y537S mutation elacestrant inhibited growth, while fulvestrant had limited activity. Here, we describe a more complete in vivo dataset describing elacestrant activity versus fulvestrant in multiple patient-derived xenograft (PDX) models harboring ESR1 mutations.

Methods: Multiple PDX models harboring natural mutations in ESR1 or genetically-engineered CRISPR models were used to assess the anti-tumor efficacy and the pharmacokinetic/pharmacodynamic properties of elacestrant and fulvestrant.

Results: Elacestrant significantly inhibited the growth of xenograft models harboring ESR1 mutations, including those harboring Y537S or D538G mutations and models that were insensitive to fulvestrant and tamoxifen.

Citation Format: Patel H, Tao N, Arlt H, Bihani T. Anti-tumor activity of elacestrant (RAD1901) in models harboring ESR1 mutations resistant to standard of care therapies [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-20-08.

Cinnamaldehyde Exerts Its Antifungal Activity by Disrupting the Cell Wall Integrity of Geotrichum citri-aurantii

Our previous study showed that cinnamaldehyde (CA) significantly inhibited the mycelial growth of Geotrichum citri-aurantii, one of the main postharvest pathogens in citrus fruits. This study investigated the antifungal mechanism of CA against G. citri-aurantii. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images showed that CA treatment led to clear morphological changes in the cell walls and membranes of G. citri-aurantii. However, the membrane integrity, total lipids and ergosterol contents were not apparently affected by CA treatment. Notably, the extracellular alkaline phosphatase (AKP) activity was increased after CA treatment, suggesting impairment in cell wall permeability. A weakened fluorescence in the cell wall, a decrease in the chitin contents, and changes of ten genes involved in cell wall integrity were also observed. These results suggested that CA may exhibit its antifungal activity against G. citri-aurantii by interfering the build of cell wall and therefore lead to the damage of cell wall permeability and integrity.

A Damaged Oxidative Phosphorylation Mechanism Is Involved in the Antifungal Activity of Citral against Penicillium digitatum

Citral exhibits strong antifungal activity against Penicillium digitatum. In this study, 41 over-expressed and 84 repressed proteins in P. digitatum after 1.0 μL/mL of citral exposure for 30 min were identified by the iTRAQ technique. The proteins were closely related with oxidative phosphorylation, the TCA cycle and RNA transport. The mitochondrial complex I, complex II, complex III, complex IV and complex V, which are involved in oxidative phosphorylation were drastically affected. Among of them, the activities of mitochondrial complex I and complex IV were apparently suppressed, whereas those of mitochondrial complex II, complex III and complex V were significantly induced. Meanwhile, citral apparently triggered a reduction in the intracellular ATP, the mitochondrial membrane potential (MMP) and glutathione content, in contrast to an increase in the glutathione S-transferase activity and the accumulation of reactive oxygen species (ROS). Addition of exogenous cysteine decreased the antifungal activity. In addition, cysteine maintained the basal ROS level, deferred the decrease of MMP and the membrane damage. These results indicate that citral inhibited the growth of P. digitatum by damaging oxidative phosphorylation and cell membranes through the massive accumulation of ROS.

Antifungal mechanism of sodium dehydroacetate against Geotrichum citri-aurantii

This study investigated the potential anti-fungal mechanisms of sodium dehydroacetate (SD) against Geotrichum citri-aurantii. The results showed that the cell wall integrity of G. citri-aurantii was not affected, whereas the membrane permeability of G. citri-aurantii mycelia was visibly altered by SD. Dramatic morphological changes of the mycelia, such as loss of cytoplasm, plasmolysis, and dissolution of intracellular substances, were observed by scanning electron microscopy and transmission electron microscopy analyses, indicating that the mycelium is severely damaged by the SD treatment. Furthermore, SD apparently induced a decrease in the intracellular ATP content before 30 min of exposure. An increase in the activity of the Na⁺/K⁺-ATPase was also observed, indicating that Na⁺ ions might enter the cell and thus disturb the energy supply. Taken together, this study's findings suggest that the anti-fungal activity of SD against G. citri-aurantii can be attributed to the disruption of cell membrane permeability and energy metabolism.

Octanal inhibits spore germination of Penicillium digitatum involving membrane peroxidation

Octanal is a potential alternative to chemical fungicides in controlling postharvest disease of citrus fruit. In this study, the antifungal activity and the underlying mechanism of octanal against spore germination of Penicillium digitatum, one of the main postharvest pathogens in citrus, were investigated. Results showed that octanal at different concentrations (0, 0.25, 0.50, 1.00, 2.00 μl/ml) inhibited the growth of P. digitatum spores in a dose-dependent manner. The morphology and the membrane permeability of P. digitatum spores were visibly altered by 0.25 and 2.00 μl/ml of octanal. Meanwhile, octanal decreased the total lipids contents of P. digitatum spores, indicating that the membrane integrity is damaged. Furthermore, octanal apparently induced the massive accumulation of total malonaldehyde (MDA) and the reactive oxygen species (ROS). An increase in the activities of lipoxygenase (LOX), NADH oxidase, superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) was also observed. These results suggested that a membrane damage mechanism involving membrane peroxidation might contribute to the antifungal activity of octanal against P. digitatum spores.

Simultaneous measurement of thermal conductivity and heat capacity by flash thermal imaging methods

Thermal properties are important for material applications involved with temperature. Although many measurement methods are available, they may not be convenient to use or have not been demonstrated suitable for testing of a wide range of materials. To address this issue, we developed a new method for the nondestructive measurement of the thermal effusivity of bulk materials with uniform property. This method is based on the pulsed thermal imaging-multilayer analysis (PTI-MLA) method that has been commonly used for testing of coating materials. Because the test sample for PTI-MLA has to be in a two-layer configuration, we have found a commonly used commercial tape to construct such test samples with the tape as the first-layer material and the bulk material as the substrate. This method was evaluated for testing of six selected solid materials with a wide range of thermal properties covering most engineering materials. To determine both thermal conductivity and heat capacity, we also measured the thermal diffusivity of these six materials by the well-established flash method using the same experimental instruments with a different system setup. This paper provides a description of these methods, presents detailed experimental tests and data analyses, and discusses measurement results and their comparison with literature values.

[Mediator effect analysis of the trait coping style on job stress and fatigue of the military personnel stationed in plateau and high cold region]

Objective: To investigate the fatigue status of military personnel stationed in plateau and high cold region, and to analyze the mediator effect of trait coping style on job stress and fatigue. Methods: In October 2010, with the method of cluster random sampling survey, 531 military personnel stationed in plateau and high cold region were chosen as subject. The fatigue status were evaluated by the Chinese version multidimensional fatigue inventory (MFI-20) , job stress were evaluated by the Job Stress Survey (JSS) , and trait coping style were evaluated by the Trait Coping Style Questionnaire (TCSQ) . Results: According to the information of different population characteristics, mean rank of physical fatigue about the urban (town) group were higher than that of rural group (Z=-2.200, P<0.05) ; mean rank of reduced motivation about the urban (town) group were higher than that of rural group (Z=-2.781, P<0.05) ; mean rank of general fatigue scores about the urban (town) group were higher than that of rural group (Z=-3.026, P<0.05) ; mean rank of physical fatigue about the up or equal 20-years old age group were higher than that of below 20-years old age group (Z=-4.045, P<0.05) ; mean rank of reduced motivation about the up or equal 20-years old age group were higher than that of below 20-years old age group (Z=-2.182, P<0.05) ; mean rank of mental fatigue about the up or equal 20-years old age group were higher than that of below 20-years old age group (Z=-2.879, P<0.05) ; mean rank of general fatigue scores about the up or equal 20-years old age group were higher than that of below 20-years old age group (Z=-3.647, P<0.05) ; mean rank of reduced motivation were significant statistical difference among the military officers, sergeancy and soldier group (F=18.965, P<0.05) ; mean rank of general fatigue scores were significant statistical difference among the military officers, sergeancy and soldier group (F=14.711, P<0.05) . The score of negative coping style were positively correlated with the score of physical fatigue (r(s)=0.129) , reduced activity (r(s)=0.123) , reduced motivation (r(s)=0.149) and general fatigue (r(s)=0.174) respectively, the score of organizational support lack strength were positively correlated with the score of physical fatigue (r(s)=0.090) , reduced activity (r(s)=0.098) , reduced motivation (r(s)=0.099) and general fatigue (r(s)=0.130) respectively. The mediator effect of negative coping style on the job stress and fatigue was 0.013 (P<0.01) . Conclusion: The fatigue statuses of the urban (town) group and the up or equal 20-years old age group are poor, and the negative coping style plays mediator effect on the job stress and fatigue.

Transcriptional profiling analysis of Penicillium digitatum, the causal agent of citrus green mold, unravels an inhibited ergosterol biosynthesis pathway in response to citral

Background

Green mold caused by Penicillium digitatum is the most damaging postharvest diseases of citrus fruit. Previously, we have observed that citral dose-dependently inhibited the mycelial growth of P. digitatum, with the minimum inhibitory concentration (MIC) of 1.78 mg/mL, but the underlying molecular mechanism is barely understood.

Results

In this study, the transcriptional profiling of the control and 1/2MIC-citral treated P. digitatum mycelia after 30 min of exposure were analyzed by RNA-Seq. A total of 6355 genes, including 2322 up-regulated and 4033 down-regulated genes, were found to be responsive to citral. These genes were mapped to 155 KEGG pathways, mainly concerning mRNA surveillance, RNA polymerase, RNA transport, aminoacyl-tRNA biosynthesis, ABC transporter, glycolysis/gluconeogenesis, citrate cycle, oxidative phosphorylation, sulfur metabolism, nitrogen metabolism, inositol phosphate metabolism, fatty acid biosynthesis, unsaturated fatty acids biosynthesis, fatty acid metabolism, and steroid biosynthesis. Particularly, citral exposure affected the expression levels of five ergosterol biosynthetic genes (e.g. ERG7, ERG11, ERG6, ERG3 and ERG5), which corresponds well with the GC-MS results, the reduction in ergosterol content, and accumulation of massive lanosterol. In addition, ERG11, the gene responsible for lanosterol 14α-demethylase, was observed to be the key down-regulated gene in response to citral.

Conclusion

Our present finding suggests that citral could exhibit its antifungal activity against P. digitatum by the down-regulation of ergosterol biosynthesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-016-2943-4) contains supplementary material, which is available to authorized users.

Proteomic analysis of mycelial proteins from Magnaporthe oryzae under nitrogen starvation

Magnaporthe oryzae is an important model system in studies of plant pathogenic fungi, and nitrogen is a key nutrient source affecting microbial growth and development. In order to understand how nitrogen stress causes changes in mycelial proteins, we analyzed differentially expressed mycelial proteins from the M. oryzae virulent strain CH-63 using two-dimensional electrophoresis and mass spectrometry in complete medium or under nitrogen starvation conditions. A total of 975 ± 70 and 1169 ± 90 protein spots were detected in complete medium and under nitrogen starvation conditions, respectively. Forty-nine protein spots exhibited at least 2-fold up-regulation or down-regulation at the protein level according to PDQuest7.4. Moreover, 43 protein spots were successfully identified by matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight mass spectrometry. Among these spots, 6 proteins were functionally unknown and 37 proteins were categorized into 5 groups according to their functions, including development, metabolism, biosynthesis, and biological process. These 37 proteins were further analyzed for their enriched metabolic pathways by KOBAS2.0, and 14 proteins were found to be involved in glycolysis, tricarboxylic acid cycle, and nitrogen metabolism. Taken together, the regulation of M. oryzae growth under the nitrogen starvation conditions appears to be complex because of the various proteins and enzymes involved.

[Effects of job content on psychological stress in young recruits]

OBJECTIVE

To explore the effects of job content on psychological stress in young recruits.

METHODS

In October 2014, 625 young recruits enrolled in one troop of Xinjiang Military Command in 2014 were chosen as subjects by multi-stage stratified random sampling. The Chinese version of the job content questionnaire (JCQ)and the psychological stress self evaluation test (PEST)were used to investigate the subjects. The subjects were divided into two groups with scores higher and lower than the mean score of three subscales (job requirement, degree of autonomy, and social support)of JCQ to explore the effects of job content on psychological stress in young recruits. The correlation of psychological stress with three subscales of job content was evaluated using the Pearson' s correlation analysis. Binary logistic regression analysis was used to analyze the influencing factors for psychological stress.

RESULTS

The PEST score of young recruits was 49.98±9.98. Forty-five (7.68%)out of them had scores of ≥70 points and were diagnosed with high levels of psychological stress. When the subjects were grouped based on socio-demographic characteristics, a high level of psychological stress was significantly more frequent in subjects less than 20 years of age than in those not less than 20 years of age, in smoking subjects than in non-smoking subjects, and in urban residents than in rural residents (10.42% vs 5.03%, P<0.05; 10.14% vs 5.33%, P<0.05; 10.85% vs 5.88% , P <0.05). There were no significant differences in educational level or identity before recruitment between subjects with different levels of psychological stress (P>0.05). In various job content domains that had impacts on psychological stress, subjects with a low score of social support had significantly higher PEST scores than those with a high score of social support (50.96±10.35 vs 48.49±9.22, P<0.01). The PEST score was negatively correlated with the degree of autonomy and social support (r=-0.103, P<0.05; r=-0.239, P<0.05). The results of logistic regression analysis showed that job requirement and social support were influencing factors for psychological stress (OR=0.718, 95% CI= 0.718 (0.607~0.851), P<0.05; OR=1.185, 95% CI=1.185 (1.087~1.292), P<0.05).

CONCLUSION

Psychological stress of young recruits in army is not optimistic. Psychological stress is weakly negatively correlated with social support. The low scores on job requirement subscale and social support subscale may be potential protective factor and risk factor for psychological stress, respectively.

Mechanisms of ammonium assimilation by Chlorella vulgaris F1068: Isotope fractionation and proteomic approaches

Removal of ammonium (NH4(+)-N) by microalgae has evoked interest in wastewater treatment, however, the detailed mechanisms of ammonium assimilation remain mysterious. This study investigated the effects of NH4(+)-N concentration on the removal and biotransformation efficiency by Chlorella vulgaris F1068, and explored the mechanisms by (15)N isotope fractionation and proteome approaches. The results showed NH4(+)-N was efficiently removed (84.8%) by F1068 at 10mgL(-1) of NH4(+)-N. The isotope enrichment factor (ε=-2.37±0.08‰) of (15)N isotope fractionation revealed 47.6% biotransformation at above condition, while 7.0% biotransformation at 4mgL(-1) of NH4(+)-N (ε=-1.63±0.06‰). This was due to the different expression of glutamine synthetase, a key enzyme in ammonium assimilation, which was up-regulated 6.4-fold at proteome level and 18.0-fold at transcription level. The results will provide a better mechanistic understanding of ammonium assimilation by microalgae and this green technology is expected to reduce the burden of NH4(+)-N removal for municipal sewage treatment plants.

Citral exerts its antifungal activity against Penicillium digitatum by affecting the mitochondrial morphology and function

This work investigated the effect of citral on the mitochondrial morphology and function of Penicillium digitatum. Citral at concentrations of 2.0 or 4.0 μL/mL strongly damaged mitochondria of test pathogen by causing the loss of matrix and increase of irregular mitochondria. The deformation extent of the mitochondria of P. digitatum enhanced with increasing concentrations of citral, as evidenced by a decrease in intracellular ATP content and an increase in extracellular ATP content of P. digitatum cells. Oxygen consumption showed that citral resulted in an inhibition in the tricarboxylic acid cycle (TCA) pathway of P. digitatum cells, induced a decrease in activities of citrate synthetase, isocitrate dehydrogenase, α-ketoglutarate dehydrogenase, succinodehydrogenase and the content of citric acid, while enhancing the activity of malic dehydrogenase in P. digitatum cells. Our present results indicated that citral could damage the mitochondrial membrane permeability and disrupt the TCA pathway of P. digitatum.

Anti-fungal activity of Citrus reticulata Blanco essential oil against Penicillium italicum and Penicillium digitatum

The chemical composition of Citrus reticulata Blanco essential oil was analysed using GC/MS. Monoterpene hydrocarbons (C10H16) constituted the majority (88.96%, w/w) of the total oil. The oils dose-dependently inhibited Penicillium italicum and Penicillium digitatum. The anti-fungal activity of the oils against P. italicum was attributed to citronellol, octanal, citral, decanal, nonanal, β-pinene, linalool, and γ-terpinene, whereas anti-fungal activity against P. digitatum is attributed to octanal, decanal, nonanal, limonene, citral, γ-terpinene, linalool, and α-terpineol. The oils altered the hyphal morphology of P. italicum and P. digitatum by causing loss of cytoplasm and distortion of the mycelia. The oils significantly altered extracellular conductivity, the release of cell constituents, and the total lipid content of P. italicum and P. digitatum. The results suggest that C. reticulata Blanco essential oils generate cytotoxicity in P. italicum and P. digitatum by disrupting cell membrane integrity and causing the leakage of cell components.

Efficiency assessment and pH effect in removing nitrogen and phosphorus by algae-bacteria combined system of Chlorella vulgaris and Bacillus licheniformis

To achieve better removal of NH4(+) and TP in wastewater, a new algae-bacteria combined system of Chlorella vulgaris and Bacillus licheniformis was investigated in a 6-d experiment. The results showed that 78% of NH4(+) could be removed in the combined system, while 29% in single algae system and only 1% in single bacteria system. Approximately 92% of TP was removed in the combined system, compared with 55% and 78% in single algae and bacteria system, respectively. B. licheniformis was proven to be a growth-promoting bacterium for C. vulgaris by comparing Chl a concentrations in the single and combined systems. In the removal process, pH of the combined system was observed to reduce significantly from 7.0 to 3.5. Whereas with pH regulated to 7.0, higher removal efficiencies of NH4(+) (86%) and TP (93%) were achieved along with the recovery of algal cells and the increase of Chl a. These results suggest that nutrients in wastewater can be removed efficiently by the algae-bacteria combined system and pH control is crucial in the process.

Subcellular distribution of fluoranthene in Chlorella vulgaris with the presence of cetyltrimethylammonium chloride

This study explored the possible mechanism of the joint toxicity of binary mixtures of cetyltrimethylammonium chloride (CTAC) and fluoranthene (Flu) to the green alga Chlorella vulgaris by examining the subcellular distribution of Flu within the alga. The joint action of CTAC (100 μg L(-1)) and Flu (0-200 μg L(-1)) on the algae changed from a synergetic effect (0-50 μg L(-1)) to an antagonistic effect (50-200 μg L(-1)) with an increase of the Flu concentration. The Flu uptake was enhanced by the presence of CTAC through the intracellular detection of Flu. Furthermore, the highest amount of Flu bound to the cytosol, whereas the least amount bound to the cellular debris when synergistic effect was observed at 2.5 μg L(-1) Flu. However, the highest amount of Flu bound to the cellular debris, whereas the least amount bound to the organelles when antagonistic effect was displayed at 200 μg L(-1) Flu. The different subcellular distribution of Flu may affect the uptake of the highly toxic CTAC by the algae in the binary mixture, and consequently lead to a different level of CTAC toxicity. The abovementioned results indicate that the subcellular distribution of chemicals can be used to elucidate possible mechanisms for the joint toxicity of their binary mixtures to aquatic organisms.

HLA DRB allele polymorphisms and risk of cervical cancer associated with human papillomavirus infection: a population study in China

OBJECTIVE

Persistent infection with high-risk human papillomavirus (HPV) is the main cause of cervical cancer. Environmental, behavioral, and ill-defined genetic factors have also been implicated in the pathogenesis of this disease. To determine whether human leukocyte antigen (HLA) DRB alleles are associated with cervical cancer and HPV infections in the Chinese population, HLA genotypes were examined in 69 cervical cancer patients and 201 controls.

MATERIALS AND METHODS

Polymorphisms in HLA-DRB genes were genotyped using oligoneucleotide arrays, and the magnitude of associations was determined by logistic regression analysis.

RESULTS

HLA-DRB1*13 (OR = 4.01 95% CI, 1.703-9.442) and HLA-DRB1*3(17) (OR = 2.661 95% CI, 1.267-5.558) were associated with an increased risk of cervical cancer, and DRB1*09012 (OR = 0.182, 95% CI, 0.079-0.418 and DRB1*1201 (OR = 0.35 95% CI, 0.142-0.863 were associated with a decreased risk. The risk associations of HPV infection were increased in women carrying the HLA-DRB1*09012 (OR = 1.924; 95% CI, 1.08 -3.427) and DRB3(52)*0101 (OR = 7.527 95% CI, 0.909-62.347) alleles. Among cervical cancer patients, the risk associations differed between HPV positive and negative cases for several alleles; increased risk of cervical cancer was associated with DRB3 (52)*02/03 (OR, 12.794; 95% CI, 5.007-32.691) and DRB1*3(17) (OR = 3.48; 95% CI, 1.261-9.604), and decreased risk was associated with DRB1*09012 and DRB5(51)*01/02. Furthermore, HPV16-containing cervical cancer cases differed from non-HPV16 subjects in their positive association with DRB1*1501 (OR = 4.173; 95% CI, 1.065-16.356) and DRB5(51)*0101/0201, and their negative association with DRB4(53)*0101 (OR = 0.329; 95% CI,0.122-0.888).

CONCLUSIONS

The present results provide further evidence that certain HLA class II allele polymorphisms are involved in the genetic susceptibility to cervical cancer and HPV infection in the Chinese population from an area with a high incidence of this neoplasia.

Carotenoid accumulation in postharvest "Cara Cara" navel orange (Citrus sinensis Osbeck) fruits stored at different temperatures was transcriptionally regulated in a tissue-dependent manner

The main objective of this work was to investigate the effect of storage temperature (4 and 20 °C) on carotenoid accumulation and on the expression levels of seven carotenoid biosynthetic genes (Psy, Pds, Zds, Lcyb, Lcye, Hyb and Zep) in postharvest 'Cara Cara' navel orange (C. sinensis Osbeck) fruits. Storage at 20 °C rapidly increased the carotenoid content in the peel, whereas the content remained unchanged in the pulp before 35 days of storage. By contrast, storage at 4 °C maintained the carotenoid content in the peel before 35 days of storage, after which it slightly increased as time progressed. However, the content in the pulp gradually increased over the entire storage period. In the peel, the gene expressions of Psy and Lcyb were up-regulated at 20 °C but remained unchanged at 4 °C. In addition, the gene expressions of Zds, Hyb, and Zep were repressed at both temperatures before the early storage, followed by a rapid increase only at 20 °C. Then the expressions remained constant level at both temperatures, with the expression level at 20 °C higher than that at 4 °C. Low temperature (4 °C) apparently induced the expression of all the test carotenoid biosynthetic genes in the pulp, in contrast to the nearly stable level at 20 °C. Our present study suggests that the carotenoid biosynthesis in postharvest 'Cara Cara' fruits is transcriptionally regulated, and storage temperature affects the carotenoid accumulation and gene expression in a tissue-dependent manner.

KEY MESSAGE

Temperature could affect the carotenoid biosynthesis in postharvest 'Cara Cara' fruits in a tissue-dependent manner. The carotenoid biosynthesis in postharvest 'Cara Cara' fruits was transcriptionally regulated by correlated genes.

Antioxidant efficacy of extracts produced from pickled and dried mustard in rapeseed and peanut oils

Antioxidant efficacy of 70% ethanol extract (EE), 70% methanol extract (ME), and water extract (WE) produced from pickled and dried mustard (Brassica juncea Coss. var. foliosa Bailey) was evaluated in rapeseed and peanut oils by using the Schaal oven method. The protective effects of aforesaid 3 extracts in stabilizing vegetable oils were tested by measuring their peroxide values, conjugated diene values, and p-anisidine values during storage of 15 d at 60 °C. Results showed that the different solvent extracts produced from pickled and dried mustard, at concentrations of 0.5% and 1.0% (w/w) in vegetable oils, could significantly (P < 0.05) lower the peroxide value, conjugated diene value, and p-anisidine value of oils during storage at 60 °C. However, the extracts at various concentrations showed a less antioxidant effect than butylated hydroxytoluene (BHT) at 200 ppm. The ultraviolet spectra of different extracts exhibited a single maximum absorbance at 268 nm. The qualitative analysis of antioxidants present in the extracts was carried out by reverse phase high performance liquid chromatography (HPLC) using a C18 column. Two phenolic compounds, gallic and protocatechuric acids, were identified. The antioxidant activity of the extracts might be attributed to the presence of these phenolics. These results indicated that the pickled and dried mustard could be used as a potential source of natural antioxidants.

PRACTICAL APPLICATION

The antioxidant activity of extracts produced from pickled and dried mustard toward rapeseed and peanut oils oxidation and the characterization of active phenolic compounds may be useful in developing natural antioxidants for vegetable oils. Moreover, the extracts could safely be used as potential antioxidant to suppress lipid oxidation in lipid-containing food products.

Isolation and characterization of a Pichia anomala strain: a promising candidate for bioethanol production

A yeast strain designated as Y-1 was isolated and characterized from wine yeast ("Jiuqu"). Based on the morphological and biochemical results, along with the rDNA internal transcribed spacer region (ITS), Y-1 was identified to be a Pichia anomala strain. Y-1 is an ethanol-tolerant strain, enduring ethanol concentrations of up to 14 %. Y-1 growth medium conditions were optimized, results showing good growth in medium with pH ranges from 3.5-6.5, temperature ranges from 25-30 °C, and inoculums range of 8 %-12 %, while optimum growth conditions were reached at a temperature of 30 °C, pH 5.0, and inoculums of 10 %. Furthermore, when the alkaline hydrolyzed Shatian pummelo peel solutions were inoculated with 10 % Y-1 and fermented at 30 °C for 6 d, 4.7 % pure ethanol (w/w) was produced, as evidenced by gas chromatography analysis. Our present study shows potential for the Y-1 strain to be a promising candidate for bioethanol production.

Functional characterization of Citrus PSY gene in Hongkong kumquat (Fortunella hindsii Swingle)

Citrus, rich in carotenoids, is the most important fruit crop based on the total annual production. In the carotenoid biosynthesis pathway, phytoene synthase (PSY, EC 2.5.1.32) catalyzes the dimerization of two molecules of geranylgeranyl pyrophosphate (GGPP) to phytoene and has been shown to be a rate-limiting enzyme for the synthesis of carotenoids. In this study, we investigated catalytic activity of CsPSY from Cara Cara navel orange (Citrus sinensis Osbeck) by heterologous expression in Escherichia coli containing a GGPP-producing plasmid. Moreover, the effects of CsPSY overexpression on carotenoid accumulation were also functionally analyzed in transgenic Hongkong kumquat (Fortunella hindsii Swingle). The resulting transgenic plants produced orange fruits, and extracts from the fruits of four overexpressing plants had a 2.5-fold average increase of phytoene with the content approximately 71.38 microg/g fresh weight. Lycopene, beta-carotene, and beta-cryptoxanthin in transgenic fruits were also markedly increased, whereas the levels of lutein and violaxanthin kept nearly unchanged with 1.1-1.3 folds variation. Transcript levels of carotenoid biosynthetic genes in the CsPSY overexpressed plants remained unaltered except that PDS and ZDS showed a minor increase. This study suggests that CsPSY plays a crucial role in citrus carotenoid biosynthesis and could be used as a means of engineering fruit crop for the production of carotenoids.