Downregulation of SUN2 promotes metastasis of colon cancer by activating BDNF/TrkB signalling by interacting with SIRT1.

Distant metastasis is the major cause of colon cancer (CC) treatment failure. SAD1/UNC84 domain protein-2 (SUN2) is a key component of linker of the nucleoskeleton and cytoskeleton (LINC) complexes that may be relevant for metastasis in several cancers. Here, we first confirmed that SUN2 levels were significantly lower in primary CC tissues and distant metastasis than in normal colon tissues, and high SUN2 expression predicted good overall survival. Overexpression of SUN2 or knockdown of SUN2 inhibited or promoted cell migration and invasion in vitro, respectively. Moreover, silencing of SUN2 promoted metastasis in vivo. Mechanistically, we showed that SUN2 exerts its tumour suppressor functions by decreasing the expression of brain derived neurotrophic factor (BDNF) to inhibit BDNF/tropomyosin-related kinase B (TrkB) signalling. Additionally, SUN2 associated with SIRT1 and increased the acetylation of methyl-CpG binding protein 2 (MeCP2) to increase its occupancy at the BDNF promoter. Taken together, our findings indicate that SUN2 is a key component in CC progression that acts by inhibiting metastasis and that novel SUN2-SIRT1-MeCP2-BDNF signalling may prove to be useful for the development of new strategies for treating patients with CC. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The Role of the TSK/TONSL-H3.1 Pathway in Maintaining Genome Stability in Multicellular Eukaryotes.

Replication-dependent histone H3.1 and replication-independent histone H3.3 are nearly identical proteins in most multicellular eukaryotes. The N-terminal tails of these H3 variants, where the majority of histone post-translational modifications are made, typically differ by only one amino acid. Despite extensive sequence similarity with H3.3, the H3.1 variant has been hypothesized to play unique roles in cells, as it is specifically expressed and inserted into chromatin during DNA replication. However, identifying a function that is unique to H3.1 during replication has remained elusive. In this review, we discuss recent findings regarding the involvement of the H3.1 variant in regulating the TSK/TONSL-mediated resolution of stalled or broken replication forks. Uncovering this new function for the H3.1 variant has been made possible by the identification of the first proteins containing domains that can selectively bind or modify the H3.1 variant. The functional characterization of H3-variant-specific readers and writers reveals another layer of chromatin-based information regulating transcription, DNA replication, and DNA repair.

[Determination of 4 kinds of plant growth regulator in bean sprout by solid phase extraction column coupled with ultra-high performance liquid chromatography].

OBJECTIVE: A method for the determination of 6-benzylaminopurine( 6-BAP), isopentennyladenine( z-IP), 4-fluorophenoxyacetic acid( 4-FPA), 4-chlorophenoxyacetic acid( 4-CPA) in bean sprout was developed using solid phase extraction column with ultra-high performance liquid chromatography. METHODS: The sample was extracted by acetonitrile,dehydrated by salt,then centrifugation,and purified by PXC/PWA solid phase extraction column. The chromatographic analysis was carried out on C18 chromatographic column( 100 mm ×2. 1 mm,1. 8 µm),acetonitrile and sodium dihydrogen phosphate for gradient elution,diode array detector for detection,and quantified with external standard method. RESULTS: The calibration curves showed good linearity in the range of 0. 25-25 µg/mL( 6-BAP and z-IP) and 0. 50-50 µg/mL( 4-FPA and 4-CPA) with correlation coefficients greater than 0. 999. Three levels spiked recoveries were carried out using blank bean sprout extraction as substrate,the recoveries ranged from70. 0% to 96. 4%,and the relative standard deviations( RSDs) ranged from 2. 84% to12. 10%( n = 6). The qualitative limits of detections were 0. 0082-0. 075 mg/kg and the quantitative limits were 0. 027-0. 25 mg/kg for the 4 PGRs. CONCLUSION: The method is simple and easy to operate using solid phase extraction column coupled,simultaneous determination of 4 PGRs by ultra-high performance liquid chromatography,can ensure the corresponding accuracy,sensitivity and precision.

Positive effect of HPV status on prognostic value of blood lymphocyte-to-monocyte ratio in advanced cervical carcinoma.

BACKGROUND: This retrospective study aimed to investigate the prognostic significance of pretreatment lymphocyte-to-monocyte ratio (LMR) in locally advanced cervical cancer and its effect on overall survival. METHODS: The usual blood routine test was quantitatively performed to detect LMR. Signal strengths of human papilloma virus (HPV) type DNA in detected cervical cancer samples using hybrid capture 2 were analyzed in relative light units (RLU) compared with 1 pg/mL of HPV type 16 DNA-positive control (RLU/PC) samples. A total of 1.0 RLU/PC (~1 pg/mL) was used as the threshold for a positive result. The HPV-positive specimens were typed using reverse-hybridization line probe assay. RESULTS: The LMR and HPV DNA were found to be independent prognostic markers for 5-year overall survival (OS) and progression-free survival, respectively. Their joint detection may further enhance the predictive value for OS. In the positive HR (high risk)-HPV DNA status subgroup, LMR had a positive effect on improved OS but not in the non-HR HPV DNA status subgroup. CONCLUSIONS: The LMR and HR-HPV DNA status can be identified as independent prognostic factors. The different influences of LMR in combined chemoradiotherapy on survival may be related to HR-HPV DNA status. The combined detection of LMR and HR-HPV DNA status may contribute to screening prognosis.

Qualitative and quantitative analysis of solid renal tumors by high-frame-rate contrast-enhanced ultrasound.

OBJECTIVE: To analyze the characteristics of high-frame-rate contrast-enhanced ultrasound (H-CEUS) in solid renal tumors using qualitative and quantitative methods. METHODS: Seventy-five patients who underwent preoperative conventional ultrasound (US), conventional contrast-enhanced ultrasound (C-CEUS), and H-CEUS examination of renal tumors were retrospectively analyzed, with a total of 89 renal masses. The masses were divided into the benign (30 masses) and malignant groups (59 masses) based on the results of enhanced computer tomography and pathology. The location, diameter, shape, border, calcification, and color doppler blood flow imaging (CDFI) of the lesions were observed by US, and the characteristics of the C-CEUS and H-CEUS images were qualitatively and quantitatively analyzed. The χ² test or Fisher's exact probability method was used to compare the US image characteristics between the benign and malignant groups, and the image characteristics of C-CEUS and H-CEUS between the benign and malignant groups. Moreover, the nonparametric Mann-Whitney test was used to compare the differences in C-CEUS and H-CEUS time-intensity curve (TIC) parameters. RESULTS: Significant differences in gender, surgical approach, echogenicity, and CDFI were observed between the malignant and benign groups (p = 0.003, < 0.001, < 0.001, = 0003). Qualitative analysis also revealed significant differences in the mode of wash-out and fill-in direction between C-CEUS and H-CEUS in the malignant group (p = 0.041, 0.002). In addition, the homogeneity of enhancement showed significant differences between the two contrast models in the benign group (p = 0.009). Quantitative analysis indicated that the TIC parameters peak intensity (PI), deceleration time (DT) /2, area under the curve (AUC), and mean transition time (MTT) were significantly lower in the H-CEUS model compared to the C-CEUS model in both the benign and malignant groups. (all p < 0.001). In contrast, ascending slope of rise curve (AS) was significantly higher in the H-CEUS model compared to the C-CEUS model in the malignant group (p = 0.048). CONCLUSIONS: In renal tumors, H-CEUS shows clearer internal enhancement of the mass and the changes in the wash-out period. The quantitative TIC parameters PI, DT/2, AUC, and MTT were lower in H-CEUS compared to C-CEUS. Both the quantitative and qualitative analyses indicated that H-CEUS better displays the characteristics of solid renal masses compared with C-CEUS.

Analysis of the Relationship between Recent Small Subcortical Infarcts and Autonomic Nervous Dysfunction.

OBJECTIVE: Autonomic Nervous System (ANS) dysfunction may be involved in the pathogenesis of Cerebral Small Vessel Disease (CSVD). The study aimed to explore the relationship between Recent Small Subcortical Infarct (RSSI) and Blood Pressure Variability (BPV), and Heart Rate Variability (HRV). METHODS: A total of 588 patients from the CSVD registration research database of Henan Province were included in this study, and were divided into two groups according to the presence of RSSI. Clinical data, including demographic characteristics, disease history, laboratory indexes, 24-hour ambulatory blood pressure and electrocardiogram indicators, and imaging markers of CSVD, were collected. Univariate and binary logistic regression analyses were used to study the relationship between RSSI and indicators of laboratory, HRV and BPV in the CSVD population. RESULTS: Multivariate analysis showed that higher 24-hour mean Diastolic Blood Pressure (DBP)[Odds Ratios (OR)=1.083,95% Confidence Intervals (CI)=(1.038,1.129), p < 0.001], Standard Deviation (SD) of 24-hour DBP [OR=1.059,95%CI=(1.000,1.121), p = 0.049], nocturnal mean Systolic Blood Pressure (SBP) [OR=1.020,95%CI=(1.004,1.035), p = 0.012], nocturnal mean DBP [OR=1.025,95%CI=(1.009,1.040), p = 0.002] were independent risk factors for RSSI. In contrast, the decrease of the standard deviation of N-N intervals (SDNN) [OR=0.994,95%CI=(0.989,1.000), p = 0.035] was beneficial to the occurrence of RSSI. In addition, neutrophil counts [OR=1.138,95%CI=(1.030,1.258), p = 0.011], total cholesterol (TC) [OR=1.203,95%CI=(1.008,1.437), p = 0.041] and High-Density Lipoprotein (HDL) [OR=0.391, 95%CI=(0.195,0.786), p = 0.008] were also independently associated with the occurrence of RSSI. After adjusting for confounding factors, except for TC, the other factors remained associated with the occurrence of RSSI. CONCLUSION: Increased 24-hour mean DBP, nocturnal mean SBP and DBP, SD of 24-hour DBP and decreased SDNN were independently correlated with RSSI occurrence, suggesting that sympathetic overactivity plays a role in the pathogenesis of RSSI.

Sequential chemoradiotherapy with gemcitabine and cisplatin for locoregionally advanced nasopharyngeal carcinoma.

We investigated a new chemoradiotherapy (CRT) regimen for locoregionally advanced nasopharyngeal carcinoma (NPC). A total of 240 patients were randomly assigned to three different CRT regimens: sequential CRT [1 cycle chemotherapy + Phase I radiotherapy (RT) + 1 cycle chemotherapy + Phase II RT + 2 cycles chemotherapy] with a cisplatin-gemcitabine (GC) regimen (800 mg/m(2) gemcitabine on Days 1 and 8 and 20 mg/m(2) cisplatin on Days 1-5, every 4 weeks) (sGC-RT); sequential chemoradiotherapy with a cisplatin-fluorouracil (PF) regimen (20 mg/m(2) DDP and 500 mg/m(2) 5-FU on Days 1-5, every 4 weeks) (sPF-RT) and cisplatin-based concurrent chemoradiotherapy plus adjuvant PF chemotherapy (Con-RT + PF). The complete response rate was higher in the sGC + RT group than in the other two groups (98.75% vs. 92.50%, p < 0.01). The 3-year overall survival (OS), disease-free survival (DFS) and distant metastasis-free survival (DMFS) rates in the sGC-RT group were significantly higher than those observed in the Con-RT group (OS, 95.0% vs. 76.3%, p < 0.001; DFS, 89.9% vs. 67.5%, p < 0.001; DMFS, 92.5% vs. 76.0%, p = 0.004) and in the sPF + RT group (OS, 95.0% vs. 73.6%, p < 0.001; DFS, 89.9% vs. 63.3%, p < 0.001; DMFS, 92.5% vs. 74.7%, p = 0.002). There were no significant differences in 3-year OS, DFS and MFS rates between the Con-RT and the sPF-RT groups. The GC-RT group experienced more hematologic toxicity, constipation and rash; however, there were no differences in late RT toxicity between the groups. These results demonstrate that a sGC-RT regimen is effective and well tolerated in patients with locoregionally advanced NPC.

Induction of T-DNA amplification by retrotransposon-derived sequences.

Transformation via Agrobacterium tumefaciens (Agrobacterium) is the predominant method used to introduce exogenous DNA into plants. Transfer DNA (T-DNA) originating from Agrobacterium can be integrated as a single copy or in concatenated forms in plant genomes, but the mechanisms affecting final T-DNA structure remain unknown. In this study, we demonstrate that the inclusion of retrotransposon (RT)-derived sequences in T-DNA can increase transgene copy number by more than 50-fold in Arabidopsis thaliana (Arabidopsis). RT-mediated amplification of T-DNA results in large concatemers in the Arabidopsis genome, which are primarily induced by the long terminal repeats (LTRs) of RTs. T-DNA amplification is dependent on the activity of DNA repair proteins associated with theta-mediated end joining (TMEJ). Finally, we show that T-DNA amplification can increase the frequency of targeted mutagenesis and gene targeting. Overall, this work uncovers molecular determinants that modulate T-DNA copy number in Arabidopsis and demonstrates the utility of inducing T-DNA amplification for plant gene editing.

Regulation of gene editing using T-DNA concatenation.

Transformation via Agrobacterium tumefaciens is the predominant method used to introduce exogenous DNA into plant genomes1,2. Transfer DNA (T-DNA) originating from Agrobacterium can be integrated as a single copy or in complex concatenated forms3,4, but the mechanisms affecting final T-DNA structure remain unknown. Here we demonstrate that inclusion of retrotransposon (RT)-derived sequences in T-DNA can increase T-DNA copy number by more than 50-fold in Arabidopsis thaliana. These additional T-DNA copies are organized into large concatemers, an effect primarily induced by the long terminal repeats (LTRs) of RTs that can be replicated using non-LTR DNA repeats. We found that T-DNA concatenation is dependent on the activity of the DNA repair proteins MRE11, RAD17 and ATR. Finally, we show that T-DNA concatenation can be used to increase the frequency of targeted mutagenesis and gene targeting. Overall, this work uncovers molecular determinants that modulate T-DNA copy number in Arabidopsis and demonstrates the utility of inducing T-DNA concatenation for plant gene editing.

Blockchain-based medical health record access control scheme with efficient protection mechanism and patient control.

The patient's medical health record (PMHR) has always provided a large amount of research data to medical institutions and pharmaceutical companies, etc., and has contributed to the development in medical research. However, such PMHR data contains the patient's personal privacy and should be shared under the control of the patients, not the hospital where this data is acquired. In order to protect the privacy of PMHR data while realizing efficient data sharing, this paper proposes a blockchain-based sharing and protection scheme. In this solution, the PMHR data are encrypted and stored in a cloud server, which is equipped with an access control scheme implemented as a smart contract on a blockchain. Different from previous works, in order to ensure efficient access and reduce the workload of patients, the types of users who can apply for access are limited to hospitals and pharmaceutical companies. In order to resist the potential Man-in-the-middle (MITM) attack, we have introduced an improved proxy re-encryption scheme to ensure the secrecy of PMHR data while reducing the computational complexity. The whole system is implemented using Solidity and tested on 10 nodes for function verification. Experimental result shows that the proposed system is more efficient than previous systems. Security under the MITM attack is also ensured by security analysis.

The Positional Relationship between Lacunae and White Matter Hyperintensity in Patients with Cerebral Small Vessel Disease.

BACKGROUND: Lacunae and white matter hyperintensity (WMH) are two crucial imaging biomarkers of cerebral small vessel disease (CSVD). Multiple studies have revealed a close relationship between WMH and lacunae and found that a double penumbra existed at the edge of WMH that affects lacunae formation. The study aimed to explore the spatial distribution characteristics and possible influencing factors of lacuna in relation to white matter hyperintensity in patients with CSVD. METHODS: A total of 480 CSVD patients with WMH and with or without lacunae were included. Data about blood biochemical indicators, cerebrovascular CT angiography, 24-hour ambulatory blood pressure and ambulatory electrocardiogram, brain magnetic resonance imaging, and transcranial Doppler ultrasound were gathered from all subjects. They were categorised into four groups based on the spatial interaction between lacunae and WMH. Univariate analyses and multiple logistic regression analyses were used to compare the differences in traditional vascular risk factors, heart rate and blood pressure indicators, arterial pulsatility index (PI) values, and arterial stenosis among different groups. RESULTS: The average age of 480 patients was (58.63 ± 11.91) years, with 347 males (72.3%). Univariate analysis indicated that age, fasting blood glucose, triglycerides, total cholesterol, highdensity lipoprotein, 24-hour and daytime and night systolic and diastolic blood pressure, nocturnal heart rate, heart rate variability, PI values of ipsilateral and contralateral MCA (middle cerebral artery) and ICA (Internal carotid artery) of the lacunae, Fazekas score of PWMH (periventricular white matter hyperintensities), the proportion of MCA or ICA with stenosis rate over 50% on the ipsilateral side of the lacunae were significantly different between different groups (p < 0.05). High fasting blood glucose (OR=1.632, 95% CI= (1.128, 2.361), p =0.009), (OR=1.789, 95%CI= (1.270, 2.520), p = 0.001), (OR=1.806, 95% CI= (1.292, 2.524), p =0.001) was identified as a risk factor for lacunae formation by logistic regression analysis. CONCLUSION: High fasting blood glucose can be considered a risk factor for lacunae formation in patients with WMH. The more severe the PWMH and the higher the nocturnal heart rate, the more likely the lacunae, as well as PWMH, overlap completely. Ipsilateral arteriosclerosis and stenosis are independent risk factors for no contact between lacunae and PWMH.

Association of Blood Lipid Profile Components with White Matter Hyperintensity Burden in Cerebral Small Vessel Disease.

BACKGROUND: Cerebral small vessel disease (CSVD) refers to a common cerebrovascular disease and white matter hyperintensities (WMHs) constitute a typical feature of CSVD. However, there has not been a large number of studies investigating the relationship between lipid profile components and WMHs. METHODS: Altogether, 1019 patients with CSVD were enrolled at the First Affiliated Hospital of Zhengzhou University between April 2016 to December 2021. Baseline data were collected for all patients, including demographic characteristics and clinical data. WMH volumes were evaluated by two experienced neurologists using the MRIcro software. Multivariate regression analysis was used to investigate the relationship among the severity of WMHs, blood lipids and common risk factors. RESULTS: Altogether, 1019 patients with CSVD were enrolled, including 255 in the severe WMH group and 764 in the mild WMH group. After including age, sex and blood lipids to construct a multivariate logistic regression equation, we observed that the severity of WMHs was independently predicted by low-density lipoprotein (LDL), homocysteine level and history of cerebral infarction. CONCLUSION: We used WMH volume, a highly accurate measure, to assess its relationship with lipid profiles. The WMH volume increased with a decrease in LDL. This relationship was more significant, especially among the subgroups of patients aged <70 years and men. Patients with cerebral infarction and higher homocysteine levels were more likely to have higher WMH volumes. Our study has provided a reference for clinical diagnosis and therapy, especially for discussing the role of blood lipid profiles in the pathophysiology of CSVD.

Correlation between neutrophil gelatinase phase lipocalin and cerebral small vessel disease.

Background: Cerebral small vessel disease (CSVD) is common in the elderly population. Neutrophil gelatinase-associated lipocalin (NGAL) is closely related to cardiovascular and cerebrovascular diseases. NGAL causes pathological changes, such as damage to the vascular endothelium, by causing inflammation, which results in other related diseases. The purpose of this study was to investigate whether serum NGAL levels could predict disease severity in patients with CSVD. Methods: The patients with CSVD who visited the Department of Neurology at the First Affiliated Hospital of Zhengzhou University between January 2018 and June 2022 were prospectively included. The total CSVD burden score was calculated using whole-brain magnetic resonance imaging (MRI), and the patients were divided into a mild group (total CSVD burden score < 2 points) and a severe group (total CSVD burden score ≥ 2 points). Age, sex, height, smoking and alcohol consumption history, medical history, and serological results of patients were collected to perform the univariate analysis. Multivariate logistic regression was used to analyze the risk factors that affect CSVD severity. The multiple linear regression method was used to analyze which individual CSVD markers (periventricular white matter hyperintensities, deep white matter hyperintensities, lacune, and cerebral microbleed) play a role in the association between total CSVD burden score and NGAL. Results: A total of 427 patients with CSVD (140 in the mild group and 287 in the severe group) were included in the study. A multivariate logistic regression analysis showed that the following factors were significantly associated with CSVD severity: male sex [odds ratio(OR), 1.912; 95% confidence interval (CI), 1.150-3.179], age (OR, 1.046; 95% CI, 1.022-1.070), history of cerebrovascular disease (OR, 3.050; 95% CI, 1.764-5.274), serum NGAL level (OR, 1.005; 95% CI, 1.002-1.008), and diabetes (OR, 2.593; 95% CI, 1.424-4.722). A multivariate linear regression shows that periventricular white matter hyperintensities and cerebral microbleed are associated with serum NGAL concentrations (P < 0.05). Conclusion: Serum NGAL level is closely related to CSVD severity and is a risk factor for the burden of CSVD brain damage. Serum NGAL has high specificity in reflecting the severity of CSVD.

Carotid contrast-enhanced ultrasonography combined with sirtuin-3 in the diagnosis of plaques in carotid atherosclerosis.

BACKGROUND: Carotid atherosclerosis (CAS) is one of the main causes of ischemic stroke. Currently, the clinical evidence for contrast-enhanced ultrasonography (CEUS) as a method for diagnosing CAS is still inadequate. Sirtuin-3 (SIRT3) is associated with the inflammation response; however, few studies have evaluated SIRT3 in CAS. OBJECTIVES: To investigate the role of SIRT3 in CAS patients and its diagnostic value for unstable plaques when combined with CEUS. MATERIAL AND METHODS: This is a prospective observational study including 517 CAS patients who were admitted to our hospital from January 2015 to December 2020. All patients received a normal Doppler ultrasound, CEUS and magnetic resonance imaging (MRI). The latter was used as the gold standard in evaluating plaque conditions. Serum SIRT3 levels were measured using an enzyme-linked immunosorbent assay (ELISA). Serum levels of total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-ch), low-density lipoprotein cholesterol (LDL-ch), C-reactive protein (CRP), and interleukin (IL)-6 levels were measured and recorded. RESULTS: Patients with severe CAS showed significantly higher levels of CRP, IL-6, TC, and LDL-ch, a higher frequency of unstable plaques, as well as a lower level of HDL-ch. In patients with severe CAS and CAS patients with stable plaques, the levels of SIRT3 were markedly lower. Patients with a high expression of SIRT3 showed significantly lower levels of CRP, IL-6, TC and LDL-ch, and higher levels of HDL-ch, as well as a lower frequency of unstable plaques. Receiver operating characteristic (ROC) curves showed that the combination of CEUS and SIRT3 could achieve high sensitivity and specificity in the diagnosis of unstable plaques. High levels of C-reactive protein, IL-6, TC, TG and LDL-ch, as well as low levels of SIRT3 and HDL-ch, and current smoking were risk factors of unstable plaques in CAS patients. CONCLUSIONS: A low expression of SIRT3 predicted a higher risk for unstable plaques in CAS patients. The combination of CEUS and SIRT3 is a potential strategy for diagnosing unstable plaques.

A metabolic daylength measurement system mediates winter photoperiodism in plants.

Plants have served as a preeminent study system for photoperiodism due to their propensity to flower in concordance with the seasons. A nearly singular focus on understanding photoperiodic flowering has prevented the discovery of other photoperiod measuring systems necessary for vegetative health. Here, we use bioinformatics to identify photoperiod-induced genes in Arabidopsis. We show that one, PP2-A13, is expressed exclusively in, and required for, plant fitness in short, winter-like photoperiods. We create a real-time photoperiod reporter, using the PP2-A13 promoter driving luciferase, and show that photoperiodic regulation is independent of the canonical CO/FT mechanism for photoperiodic flowering. We then reveal that photosynthesis combines with circadian-clock-controlled starch production to regulate cellular sucrose levels to control photoperiodic expression of PP2-A13. This work demonstrates the existence of a photoperiod measuring system housed in the metabolic network of plants that functions to control seasonal cellular health.

The YDA-MKK4/MKK5-MPK3/MPK6 Cascade Functions Downstream of the RGF1-RGI Ligand-Receptor Pair in Regulating Mitotic Activity in Root Apical Meristem.

The mitotic activity of root apical meristem (RAM) is critical to primary root growth and development. Previous studies have identified the roles of ROOT GROWTH FACTOR 1 (RGF1), a peptide ligand, and its receptors, RGF1 INSENSITIVEs (RGIs), a clade of five leucine-rich-repeat receptor-like kinases, in promoting cell division in the RAM, which determines the primary root length. However, the downstream signaling components remain elusive. In this study, we identify a complete mitogen-activated protein kinase (MAPK or MPK) cascade, composed of YDA, MKK4/MKK5, and MPK3/MPK6, that functions downstream of the RGF1-RGI ligand-receptor pair. Similar to the rgi1/2/3/4/5 quintuple mutant, loss-of-function mutants of MPK3 and MPK6, MKK4 and MKK5, or YDA show a short-root phenotype, which is associated with reduced mitotic activity and lower expression of PLETHORA 1 (PLT1)/PLT2 in the RAM. Furthermore, MPK3/MPK6 activation in response to exogenous RGF1 treatment is impaired in the rgi1/2/3/4/5 quintuple, yda single, and mkk4 mkk5 double mutants. Epistatic analyses demonstrated that the expression of constitutively active MKK4, MKK5, or YDA driven by the RGI2 promoter can rescue the short-root phenotype of the rgi1/2/3/4/5 mutant. Taken together, these results suggest that the YDA-MKK4/MKK5-MPK3/MPK6 cascade functions downstream of the RGF1-RGI ligand-receptor pair and upstream of PLT1/PLT2 to modulate the stem cell population and primary root growth in Arabidopsis.

Parthenolide inhibits human lung cancer cell growth by modulating the IGF­1R/PI3K/Akt signaling pathway.

Lung cancer is the leading cause of cancer­associated mortality worldwide. Parthenolide (PTL), a natural product extracted from the plant Tanacetum parthenium, (a flowering plant in the daisy family, Asteraceae) has been reported to inhibit cancer cell growth, including that of human lung cancer. However, the underlying mechanisms by which PTL exerts its anticancer effect have remained to be fully elucidated. In the present study, Cell Counting Kit­8 and colony formation assays were used to assess the effect of PTL to inhibit cell proliferation, a wound­healing assay was performed to assess cell migration and western blot analysis and PCR were employed to reveal the molecular mechanisms by which PTL inhibits human lung carcinoma cell growth. The results indicated that PTL substantially inhibited cell proliferation and migration in two lung cancer cell lines A549 and H1299. Mechanistically, the phosphorylation of insulin­like growth factor 1 receptor (IGF­1R), Akt and forkhead box O3α (FoxO3α) was blocked by PTL. Furthermore, IGF­1­induced Akt [protein kinase B or (PKB)] and FoxO3α phosphorylation were also inhibited by PTL treatment. In addition, PTL significantly suppressed lung cancer growth in a subcutaneous xenograft mouse model. Taken together, the present in vivo and in vitro results indicate that PTL may suppress lung cancer growth through inhibiting IGF­1R­mediated PI3K/Akt/FoxO3α signaling, suggesting that PTL may be an attractive candidate for the treatment of lung cancer.

Histone deacetylase 7 inhibits plakoglobin expression to promote lung cancer cell growth and metastasis.

Plakoglobin is a tumor suppressor gene in lung cancer; however, the mechanism by which it is downregulated in lung cancer is largely unknown. The aim of the present study was to investigate whether histone deacetylases (HDACs) regulate plakoglobin expression in lung cancer. The effects of overexpression or knockdown of HDAC7 on plakoglobin were determined using stably transfected lung cancer cell lines. Chromatin immunoprecipitation assays were performed to elucidate the mechanisms underlying the HDAC7­induced suppression of plakoglobin. A Cell Counting Kit­8 and Transwell assays were performed, and a nude mouse in vivo model was established to investigate the role of the HDAC7/plakoglobin pathway in cell migration, invasion and metastasis. Ectopic expression of HDAC7 was identified to suppress mRNA and protein levels of plakoglobin in lung cancer cells, whereas silencing HDAC7 with short hairpin RNA increased the expression of plakoglobin. HDAC7 was proposed to suppressed plakoglobin by directly binding to its promoter. Overexpression or knockdown of HDAC7 promoted or inhibited cell proliferation, migration and invasion, respectively. Furthermore, knockdown of HDAC7 significantly suppressed tumor growth and metastasis in vivo. In addition, overexpression of plakoglobin significantly reduced the enhanced cell proliferation, migration and invasion induced by ectopic HDAC7. In conclusion, suppression of plakoglobin by HDAC7 promoted the proliferation, migration, invasion and metastasis in lung cancer. This novel axis of HDAC7/plakoglobin may be valuable in the development of novel therapeutic strategies for treating patients with lung cancer.

Cryptotanshinone inhibits cellular proliferation of human lung cancer cells through downregulation ofIGF-1R/PI3K/Akt signaling pathway.

Lung cancer is one of the most commonly diagnosed malignancies worldwide. Cryptotanshinone (CPT) is a diterpene quinone compound extracted from natural plants and has been reported to have anticancer effects in several cancers including human lung cancer. However, the mechanism by which CPT acts to prevent lung cancer cell growth is largely unknown. In the present study, by using MTT assay, colony formation assay, wound healing and western blotting assays, the effects of CPT on the cell proliferation and migration of human lung cancer cells and the potential cellular signaling mechanisms were investigated. The data demonstrated that CPT exhibited anti-proliferative effects against A549 and H1299 cells. In parallel, the migration of A549 cells was also markedly inhibited by CPT treatment. Further study indicated that CPT not only inhibited the basal phosphorylation level of insulin-like growth factor 1 receptor (IGF-1R) and RAC-alpha serine/threonine-protein kinase (Akt), but also blocked IGF-1 induced IGF-1R and Akt phosphorylation. Finally, it was demonstrated that pretreatment with CPT inhibited IGF-1 induced cell proliferation of A549 and H1299 cells. In conclusion, the results of the present study indicated that CPT inhibits the proliferation and migration of lung cancer cells via a mechanism that involves inhibiting the IGF-1R-mediated phosphoinositide 3-kinase/Akt signaling pathway. The data provides evidence that CPT could be developed as a potential therapeutic agent for the treatment of lung cancer.

Functional Characterization of BoaMYB51s as Central Regulators of Indole Glucosinolate Biosynthesis in Brassica oleracea var. alboglabra Bailey.

R2R3-MYB transcription factor MYB51 is known to control indole glucosinolate (indole GSL) biosynthesis in Arabidopsis. Here, two copies of BoaMYB51 have been isolated in Chinese kale (Brassica oleracea var. alboglabra Bailey), designated BoaMYB51.1 and BoaMYB51.2, which exhibit overlapping but distinct expression levels among different organs and respond to signaling molecules in a similar pattern. It has been demonstrated a structural and functional conservation between BoaMYB51s and AtMYB51 by phylogenetic analysis, complementation studies and transient expression assay. To further investigate the transcriptional mechanism, we identified the transcriptional activation domain (TAD) and putative interacting proteins of BoaMYB51s by means of yeast (Saccharomyces cerevisiae) two hybrid. Using tobacco (Nicotiana benthamiana) transient expression assay, we confirmed that the carboxy-end is required for transcriptional activation activity of BoaMYB51s. In addition, several BoaMYB51-interacting proteins have been identified by yeast two-hybrid screening. These results provide important insights into the molecular mechanisms by which MYB51 transcriptionally regulates indole GSL biosynthesis.