Tetrad stage transient cold stress skews auxin-mediated energy metabolism balance in Chinese cabbage pollen.

Changing ambient temperature often impairs plant development and sexual reproduction, particularly pollen ontogenesis. However, mechanisms underlying cold stress-induced male sterility are not well understood. Here, we exposed Chinese cabbage (Brassica campestris) to different cold conditions during flowering and demonstrated that the tetrad stage was the most sensitive. After completion of pollen development at optimal conditions, transient cold stress at the tetrad stage still impacted auxin levels, starch and lipid accumulation, and pollen germination, ultimately resulting in partial male sterility. Transcriptome and metabolome analyses and histochemical staining indicated that the reduced pollen germination rate was due to the imbalance of energy metabolism during pollen maturation. The investigation of ß-glucuronidase (GUS)-overexpressing transgenic plants driven by the promoter of DR5 (DR5::GUS report system) combined with cell tissue staining and metabolome analysis further validated that cold stress during the tetrad stage reduced auxin levels in mature pollen grains. Low-concentration auxin treatment on floral buds at the tetrad stage before cold exposure improved the cold tolerance of mature pollen grains. Artificially changing the content of endogenous auxin during pollen maturation by spraying chemical reagents and loss-of-function investigation of the auxin biosynthesis gene YUCCA6 by artificial microRNA technology showed that starch overaccumulation severely reduced the pollen germination rate. In summary, we revealed that transient cold stress at the tetrad stage of pollen development in Chinese cabbage causes auxin-mediated starch-related energy metabolism imbalance that contributes to the decline in pollen germination rate and ultimately seed set.

Dual PI3K/mTOR inhibitor PF-04979064 regulates tumor growth in gastric cancer and enhances drug sensitivity of gastric cancer cells to 5-FU.

Gastric cancer (GC) is characterized by high tumor heterogeneity, increased surgical difficulty, and limited chemotherapy efficacy, and it is associated with a poor prognosis. The abnormal proliferation of cells involves abnormal activation of the PI3K/AKT/mTOR signaling pathway. Inhibition of this signaling pathway can inhibit tumor cell proliferation and induce cell apoptosis. This study evaluated the effect of PF-04979064, a dual inhibitor of PI3K and mTOR, on human GC cells. PF-04979064 significantly inhibited the proliferation of human gastric adenocarcinoma AGS cells and the undifferentiated GC cell line HGC-27, promoting cell apoptosis. Combination treatment with PF-04979064 and the GC first-line clinical drug 5-FU showed synergistic effects, and PF-04979064 markedly increased the sensitivity of GC cells to chemotherapy drugs. Western blot results showed that PF-04979064 significantly inhibited the PI3K/AKT/mTOR signaling pathway in GC cells, whereas RNA seq results demonstrated substantial alterations in gene expression profiles upon treatment with PF-04979064. This study provides insight into the effects of PF-04979064, thereby establishing a solid foundation for its potential clinical application in the treatment of GC.

Introducing Mn into ZIF-8 nanozyme for enhancing its catalytic activities and adding specific recognizer for detection of organophosphorus pesticides.

In order to design and establish a highly efficient and selective nanozyme-based sensing platform for the UV-vis detection of organophosphorus pesticides (OPs), Mn was introduced into ZIF-8 nanozyme for enhancing its catalytic activities and adding specific recognizer. The Mn-doped ZIF-8 (Mn-ZIF-8) nanocomposites were synthesized with a very facile one-pot method by heating the mixture of ZnO, 2-methylimidazole (Hmin) and Mn(CH3COO)2·4H2O in a solvent-free system at 180 °C for 8 h. The Mn-ZIF-8 nanocomposite showed a higher peroxidase activity and an additional thiocholine (TCh)-degradable property compared to the pristine ZIF-8. OPs could inhibit acetylcholinesterase (AChE) to catalyze the hydrolysis of acetylthiocholine (ATCh) to produce TCh, thus blocking the degradation of Mn-ZIF-8 and protecting the catalysis of the oxidation of colorless 3,3',5,5'-tetramethylbenzydine (TMB) to blue oxidized TMB (ox-TMB). Accordingly, a detection method for OPs with high sensitivity and selectivity was designed and established on the basis of the Mn-ZIF-8 nanozyme with a linear range of 0.1-20 nM and a limit of detection (LOD) as low as 54 pM.

Optimizing DUS testing for Chimonanthus praecox using feature selection based on a genetic algorithm.

Chimonanthus praecox is a famous traditional flower in China with high ornamental value. It has numerous varieties, yet its classification is highly disorganized. The distinctness, uniformity, and stability (DUS) test enables the classification and nomenclature of various species; thus, it can be used to classify the Chimonanthus varieties. In this study, flower traits were quantified using an automatic system based on pattern recognition instead of traditional manual measurement to improve the efficiency of DUS testing. A total of 42 features were quantified, including 28 features in the DUS guidelines and 14 new features proposed in this study. Eight algorithms were used to classify wintersweet, and the random forest (RF) algorithm performed the best when all features were used. The classification accuracy of the outer perianth was the highest when the features of the different parts were used for classification. A genetic algorithm was used as the feature selection algorithm to select a set of 22 reduced core features and improve the accuracy and efficiency of the classification. Using the core feature set, the classification accuracy of the RF model improved to 99.13%. Finally, K-means was used to construct a pedigree cluster tree of 23 varieties of wintersweet; evidently, wintersweet was clustered into a single class, which can be the basis for further study of genetic relationships among varieties. This study provides a novel method for DUS detection, variety identification, and pedigree analysis.

Important roles of estrogen receptor alpha in tumor progression and anti-estrogen therapy of pancreatic ductal adenocarcinoma.

AIMS: The roles of estrogen receptors (ERs) and the efficacy of anti-estrogen (E2) therapies in pancreatic cancer stay controversial. The main objectives of this study were to investigate the potential roles of ERs in tumor progression and endocrine therapies. MAIN METHODS: The ER expression status in PANC-1 and SW1990 pancreatic cancer cell lines was determined. SRB assay, colony formation assay and proliferation assay were used to investigate the responses of these cells to E2. ERα-selective agonist propylpyrazoletriol (PPT), ERß-selective agonist diarylpropionitrile (DPN), ERα over-expressed SW1990 cells, ERα knock-out PANC-1 cells and patient-derived xenografts (PDX) were applied to investigate the potential roles of ERα in pancreatic cancer. The phosphorylation of ERα-related signaling molecules extracellular regulated protein kinases (ERK1/2) and protein kinase B (AKT) were investigated. The in vivo anti-tumor efficacy and safety of letrozole (LTZ) combined with leuprorelin acetate (LA) and gemcitabine (GEM) were also preliminarily studied. KEY FINDINGS: PANC-1 cells expressed much more ERα than SW1990 cells, and ERß level was with less diversity. Accordingly, the proliferation of PANC-1 rather than SW1990 cells could be stimulated by E2, and only PANC-1 could respond to LTZ endocrine therapy in female but not male mice. The phosphorylation of ERK1/2 but not AKT was altered by over-expressed or knocking out of ERα with or without the addition of E2 and LTZ. The combination therapy of LTZ and GEM showed acceptable efficacy and safety. SIGNIFICANCE: This study showed the important roles of ERα in tumor progression and endocrine therapies of pancreatic cancer in women.

Dexamethasone inhibits pancreatic tumor growth in preclinical models: Involvement of activating glucocorticoid receptor.

Glucocorticoid receptor (GR) modulates extensive biological and pathological processes including tumor progression through diverse mechanisms. The regulatory effects of dexamethasone (DEX), a synthetic glucocorticoid, as well as its interaction with GR have been recognized beyond hematologic cancers. In the present study, we investigated the anti-cancer efficacy of DEX and the correlation with GR in pancreatic cancer, a most aggressive malignancy threatening human health. The differential levels of GR expression were examined in two human pancreatic cancer cell lines, PANC-1 and SW1990, as well as in xenografts and patient tumor tissues. DEX significantly inhibited colony formation, migration, and tumor growth of PANC-1 cells expressing abundant GR. The underlying mechanisms involved suppression of nuclear factor κB (NF-κB) phosphorylation and down-regulation of epithelial-to-mesenchymal transition (EMT), interleukin 6 (IL-6) and vascular endothelial growth factor (VEGF). The anti-cancer effects of DEX were partially reversed by GR silencing or combinational administration of GR antagonist, RU486. The dose-dependent efficacy of DEX in tumor growth inhibition was also demonstrated in a GR-positive patient-derived xenograft model along with safety in mice. DEX was less potent, however, in SW1990 cells with poor GR expression. Our findings suggest that DEX effectively inhibits pancreatic tumor growth partially through GR activation. The potential correlation between GR expression and anti-cancer efficacy of DEX may have some clinical implications.

Disease progression model of 4T1 metastatic breast cancer.

Cancer metastasis is the main cause of death in various types of cancer. However, in the field of pharmacometrics, cancer disease progression models focus on the growth of primary tumors with tumor volume or weight as target values, while the metastasis process is less mentioned. We propose a series of mathematical models to quantitatively describe and predict the disease progression of 4T1 breast cancer in the aspect of primary breast tumor, lung metastasis and white blood cell. The 4T1 cells were injected into breast fat pad of female BALB/c mice to establish an animal model of breast cancer metastasis. The number and volume of lung metastases at different times were measured. Based on the above data, a disease progression model of breast cancer lung metastasis was established and parameter values were estimated. The white blood cell growth and the primary tumor growth of 4T1 mouse are also modeled. The established models can describe the lung metastasis of 4T1 breast cancer in three aspects: (1) the increase in metastasis number; (2) the growth of metastasis volume; (3) metastasis number-size distribution at different time points. Compared with the prior metastasis models based on von Forester equation, our models distinguished the growth rate of primary tumor and metastasis and got parameter values for 4T1 mouse model. And the current models optimized the metastasis number-size distribution model by utilizing logistic function instead of the prior power function. This study provides a comprehensive description of lung metastasis progression for 4T1 breast cancer model, as well as an alternative disease progression model structure for further pharmacodynamics modeling.

Stiff limb syndrome with lower limb myoclonus: A case report.

RATIONALE: stiff limb syndrome (SLS) is a variant of stiff-man syndrome, primarily affecting a specific limb. Its diagnosis has always been challenging due to the lack of a specific confirmation test. We present a rare case of a patient with lower limb myoclonus and rigidity. PATIENT CONCERNS: A 53-year-old male presented with a sudden onset of progressive left lower extremity myoclonus and muscle rigidity for 3 days. He rapidly showed signs of right lower limb involvement with severe joint stiffness and inability to walk. DIAGNOSIS: The symptoms nature, physical examination, careful elimination of differential diagnosis suggested a diagnosis of stiff limb syndrome. INTERVENTIONS: Intravenous infusion of gamma globulin 0.4 mg/kg coupled with baclofen and clonazepam were given after admission. He also received an injection of botulinum toxin A to relieve his muscle stiffness. OUTCOMES: The patients' condition improved after the initial treatment with complete disappearance of muscle twitching. Further improvements were seen later on after the local administration of botulinum toxin A. LESSONS: Stiff limb syndrome shares the same complex symptoms with many other conditions. Its diagnosis relies heavily on clinical presentations and on ruling out other conditions. However, unusual symptoms such as myoclonus can occur in few cases and together with the rarity of the condition, the prevalence of misdiagnosis is high. Therefore, being aware and recognizing the signs and symptoms is crucial for proper management. Additionally, EMG is a very important test if the present condition is suspected. However, a negative EMG result or a negative anti-glutamic acid decarboxylase antibody test should not exclude SLS diagnosis.

N-arylpiperazine-containing compound (C2): An enhancer of sunitinib in the treatment of pancreatic cancer, involving D1DR activation.

Previous studies showed that dopamine (DA) significantly reduces the frequency of cancer stem-like cells (CSC) and enhances the efficacy of sunitinib (SUN) in the treatment of breast cancer and non-small cell lung cancer (NSCLC). To overcome the shortcomings of DA in clinical practice, the purpose of this study was to investigate the efficacy as well as the underlying mechanism of an orally available, N-arylpiperazine-containing compound C2, in the treatment of pancreatic cancer when used alone or in combination with SUN. Our results showed that C2 and SUN exerted synergistic effects on inhibiting the growth of SW1990 and PANC-1 pancreatic cancer cells. C2 significantly inhibited colony formation and migration of both cells. SW1990 xenograft and patient-derived xenograft (PDX) models were utilized for pharmacodynamic investigation in vivo. C2 alone showed little inhibition effect on tumor growth but increased the anti-tumor efficacy of SUN in both xenografts. Moreover, C2 down-regulated CSC markers (CD133 and ALDH) of both cancer cells and up-regulated the expression of dopamine receptor D1 (D1DR) in tumor. Besides, the SW1990 tumor growth was dose-dependently inhibited when the cells were pretreated with C2 before implantation. C2 increased intratumoral cAMP level, and the combination with D1DR specific antagonist SCH23390 reversed the above-mentioned effects of C2 both in vitro and in vivo, indicating the activation of D1DR may be involved in the underlying mechanism of C2 action. In summary, C2 could reduce the CSC frequency and enhance the anti-cancer effect of SUN in the treatment of pancreatic cancer, demonstrating its potential in cancer therapy.

Dopamine D1 receptor agonists inhibit lung metastasis of breast cancer reducing cancer stemness.

The leading causes of death in breast cancer patients are disease recurrence and metastasis. Growing evidence has suggested that metastasis possibly originates from cancer stem-like cells (CSCs). Previous studies indicated dopamine decreased CSC frequency through activating dopamine D1 receptor pathway. Hence, this study explored the efficacy of two dopamine D1 receptor agonists in lung metastasis of breast cancer and the preliminary mechanism. The two dopamine D1 receptor agonists, fenoldopam (FEN) and l-stepholidine (l-SPD), performed well in decreasing lung metastasis in 4T1 breast cancer model. And the cGMP in the primary tumor was significantly elevated while cAMP mildly elevated in FEN and l-SPD dosing groups. CSC markers (CD44+/CD24- and ALDH+) and MMP2 in 4T1 primary tumor were repressed after dopamine D1 receptor agonist administration while E-cadherin up-regulated. FEN and l-SPD also inhibited cancer stemness and cell motility in vitro, and the inhibitory effects could be reversed by dopamine D1 receptor antagonist SCH23390. Besides, FEN impacted the white blood cell increase caused by breast cancer disease showing decreased neutrophils but increased lymphocytes. Drug safety was verified in aspects of body weight, organ index and tissue section. In conclusion, dopamine D1 receptor agonists FEN and l-SPD showed efficacy in inhibiting metastasis along with good safety in breast cancer, thus providing an alternative for anti-metastasis therapy in the future. Furthermore, this study also indicates that dopamine D1 receptor may be a possible target for metastatic breast cancer treatment and even other cancers at a late stage.

Apatinib for patients with advanced or recurrent cervical cancer: study protocol for an open-label randomized controlled trial.

BACKGROUND: In China, cervical cancer is the fifth most commonly diagnosed cancer, and the outcomes for patients with advanced or recurrent disease are poor. Apatinib, a small molecule inhibitor of vascular endothelial growth factor receptor (VEGFR-2), is an orally bioavailable agent, which has shown survival benefit in multiple solid tumors. Based on previous research, this phase II clinical trial aims to verify apatinib's efficacy and safety in patients with advanced or recurrent cervical cancer. METHODS/DESIGN: This randomized, parallel arm, open-label, interventional trial will be carried out to evaluate the efficacy and the safety of apatinib for advanced or recurrent cervical cancer. A total of 60 eligible patients will be allocated by intention, in a ratio of 1:1, to either the experimental group or the control group. The primary endpoint is progression-free survival, the secondary endpoints include overall survival, disease control rate, objective response rate, quality of life, and adverse events. Assessments will be carried out before enrolment (baseline) and every 4 weeks after treatment. DISCUSSION: The aim of this trial is to demonstrate the clinical effect, safety, and side effects of apatinib in the treatment of advanced or recurrent cervical cancer. This study will clarify the efficacy and safety of this regimen. TRIAL REGISTRATION: Chinese Clinical Trials Registry, ChiCTR-OIN-17012164 . Registered on 24 July 2017.

Systematic identification of long non-coding RNAs during pollen development and fertilization in Brassica rapa.

The importance of long non-coding RNAs (lncRNAs) in plant development has been established, but a systematic analysis of lncRNAs expressed during pollen development and fertilization has been elusive. We performed a time series of RNA-seq experiments at five developmental stages during pollen development and three different time points after pollination in Brassica rapa and identified 12 051 putative lncRNAs. A comprehensive view of dynamic lncRNA expression networks underpinning pollen development and fertilization was provided. B. rapa lncRNAs share many common characteristics of lncRNAs: relatively short length, low expression but specific in narrow time windows, and low evolutionary conservation. Gene modules and key lncRNAs regulating reproductive development such as exine formation were uncovered. Forty-seven cis-acting lncRNAs and 451 trans-acting lncRNAs were revealed to be highly coexpressed with their target protein-coding genes. Of particular importance are the discoveries of 14 lncRNAs that were highly coexpressed with 10 function-known pollen-associated coding genes. Fifteen lncRNAs were predicted as endogenous target mimics for 13 miRNAs, and two lncRNAs were proved to be functional target mimics for miR160 after experimental verification and shown to function in pollen development. Our study provides the systematic identification of lncRNAs during pollen development and fertilization in B. rapa and forms the foundation for future genetic, genomic, and evolutionary studies.

A prospective study of freezing of gait with early Parkinson disease in Chinese patients.

This study investigated the risk factors for freezing of gait (FOG) in the early stage of Parkinson disease in China, using a sample of 248 patients who were followed for 3 years. Part III of the Unified Parkinson Disease Rating Scale and the modified Hoehn-Yahr grading scale were used to evaluate the severity of motor symptoms. Nonmotor symptoms were assessed using the Hamilton Anxiety Rating Scale, Hamilton Depression Rating Scale (HAMD), and Non-Motor Symptoms Scale (NMSS). The end-point was the presence of FOG at the end of follow-up; patients with FOG were classified as freezers. The risk factors for FOG were analyzed at the end of the first, second, and third years after baseline. There were 40 freezers (16.13%) 1 year later, 98 (39.52%) 2 years later, and 128 (51.61%) 3 years later. FOG 3 years later was associated with the following variables: depression (P = 0.003), older age, living in the countryside, lower education, akinetic-rigid style, lower limbs as site of onset, early use of levodopa, higher daily dose of levodopa, and not using amantadine or selegiline and dopamine receptor agonists (P < 0.001). Early use of amantadine, selegiline, and dopamine receptor agonists was negatively related to FOG (P < 0.001). Binary logistic regression found that FOG was associated with lower education (odds ratio [OR] = 0.012, P < 0.001), akinetic-rigid style (OR = 4.881, P = 0.024), not using dopamine receptor agonists (OR = 4.324, P = 0.035), cognitive disturbances (OR = 0.331, P = 0.007), and sleep disorders (OR = 2.418, P = 0.036). However, the cardiovascular domain of the NMSS (OR = 2.729, P = 0.001) was the only risk factor for FOG 1 year later. Two years later, FOG was associated with mixed style (OR = 0.189, P = 0.005), lower limbs as site of onset (OR = 4.772, P = 0.008), not using dopamine receptor agonists (OR = 0.031, P < 0.001), and the anxiety/somatic domain of the HAMD (OR = 0.596, P = 0.033). Scores at baseline, patients with Parkinson disease were more likely to experience FOG if: they were older, or from the countryside; had an akinetic-rigid style, anxiety, or higher NMSS scores; they used levodopa early or did not use amantadine or selegiline; their lower limbs were the site of onset; or they had more severe motor disability or higher HAMD scores at baseline.

Imidazoline type stationary phase for hydrophilic interaction chromatography and reversed-phase liquid chromatography.

An imidazoline was prepared by solvent-free microwave-assisted organic synthesis and immobilized on porous silica particles by polymerization. The resulting material was composed of both hydrophobic alkyl ester chains and hydrophilic imidazoline rings, which gave it both hydrophilic interaction and reversed-phase characteristics. The titration curve suggests that the new material has buffering capacity and acquires increasing positive charge over the pH range 9-4, and is "zwitterionic" in the upper part of this pH range. Through investigating the effect of column temperature, the water content, pH and ion strength of mobile phase on the retention time of polar compounds in highly organic eluents, it was found that the new material could be used as a hydrophilic interaction liquid chromatography (HILIC) stationary phase which involved a complex retention process consisting of partitioning, surface adsorption and electrostatic interactions. In addition, the retention behavior of aromatic compounds in different mobile phase conditions was also studied, which showed the new material mainly exhibited a partitioning mechanism in the reversed-phase liquid chromatography (RPLC) mode. The separation of six water-soluble vitamins and five aromatic compounds were achieved by using the new material in the HILIC and RPLC modes, respectively.

Synthesis and characterization of Fe3O4@SiO2@poly-L-alanine, peptide brush-magnetic microspheres through NCA chemistry for drug delivery and enrichment of BSA.

A novel Fe3O4@SiO2@poly-L-alanine peptide brush-magnetic microsphere (PBMMs) was synthesized from amine-functionalized Fe3O4 through the surface-initiated polymerization of N-carboxyanhydrides. Two materials with different peptide lengths were obtained from different amounts of N-carboxyanhydrides. These materials were characterized by Fourier transform infrared, transmission electron microscopy, large-angle powder X-ray diffraction, vibrating sample magnetometer and elemental analysis. Furthermore, the loading and release behavior of ibuprofen and the enrichment of bovine serum albumin on the two materials were investigated and it was shown that the PBMMs have a maximum uptake amount of ibuprofen of 40.3 mg g(-1), and an enrichment of bovine serum albumin of 20.9 mg g(-1). These materials are promising candidates for targeted drug delivery and protein enrichment.