Automated liver volumetry and hepatic steatosis quantification with magnetic resonance imaging proton density fat fraction.

BACKGROUND: Preoperative imaging evaluation of liver volume and hepatic steatosis for the donor affects transplantation outcomes. However, computed tomography (CT) for liver volumetry and magnetic resonance spectroscopy (MRS) for hepatic steatosis are time consuming. Therefore, we investigated the correlation of automated 3D-multi-echo-Dixon sequence magnetic resonance imaging (ME-Dixon MRI) and its derived proton density fat fraction (MRI-PDFF) with CT liver volumetry and MRS hepatic steatosis measurements in living liver donors. METHODS: This retrospective cross-sectional study was conducted from December 2017 to November 2022. We enrolled donors who received a dynamic CT scan and an MRI exam within 2 days. First, the CT volumetry was processed semiautomatically using commercial software, and ME-Dixon MRI volumetry was automatically measured using an embedded sequence. Next, the signal intensity of MRI-PDFF volumetric data was correlated with MRS as the gold standard. RESULTS: We included the 165 living donors. The total liver volume of ME-Dixon MRI was significantly correlated with CT (r = 0.913, p < 0.001). The fat percentage measured using MRI-PDFF revealed a strong correlation between automatic segmental volume and MRS (r = 0.705, p < 0.001). Furthermore, the hepatic steatosis group (MRS ≥5%) had a strong correlation than the non-hepatic steatosis group (MRS <5%) in both volumetric (r = 0.906 vs. r = 0.887) and fat fraction analysis (r = 0.779 vs. r = 0.338). CONCLUSION: Automated ME-Dixon MRI liver volumetry and MRI-PDFF were strongly correlated with CT liver volumetry and MRS hepatic steatosis measurements, especially in donors with hepatic steatosis.

Comparison of CT and gadoxetic acid-enhanced MRI with liver imaging reporting and data system to assess liver tumors before resection.

BACKGROUND/PURPOSE: Hepatocellular carcinoma (HCC) can be noninvasively diagnosed through dynamic computed tomography (CT) and magnetic resonance imaging (MRI). We compared the diagnostic performance of CT and gadoxetic acid-enhanced MRI (EOB-MRI) in categorizing tumors by using the 2018 version of the Liver Imaging Reporting And Data System (LI-RADS v2018) and assessing liver tumors before resection. METHODS: Data from a prospective cohort from October 2011 to March 2019 on 106 hepatic tumors in 96 patients with suspected malignancy were included in this study. We performed preoperative CT and EOB-MRI, and reviewed these images retrospectively. Ninety-seven tumors from 87 patients were pathologically diagnosed as HCC, and nine tumors were non-HCC. The clinical data, imaging characteristics, diagnostic performance, and outcomes of CT and EOB-MRI were analyzed and compared. RESULTS: EOB-MRI had more favorable diagnostic performance (area under curve: 0.920 vs. 0.868) and significantly higher sensitivity (86.87% vs. 69.70%, p = 0.005) than did CT. However, the specificity of EOB-MRI did not differ from that of CT (88.89% vs. 88.89%, p > 0.999). Fourteen (14.5%) patients with pathologically verified HCC had lesions categorized as LI-RADS 4 through CT and as LI-RADS 5 through EOB-MRI. Patients with EOB-MRI-categorized but not CT-categorized LI-RADS 5 lesions had significantly longer overall survival than did those with LI-RADS 4 lesions (p < 0.001). CONCLUSION: EOB-MRI had higher sensitivity than did CT in diagnosing HCC. Patients with EOB-MRI-categorized LI-RADS 5 lesions had more favorable outcomes than did those with LI-RADS 4 lesions after liver resection.

Lenvatinib Suppresses Protein Kinase B Signaling and Induces Apoptosis in Osteosarcoma Cells.

BACKGROUND/AIM: Lenvatinib, an oral multikinase inhibitor, has demonstrated promising activity in patients with osteosarcoma (OS). Therefore, it is worth exploring the inhibitory efficacy and mechanism of action of lenvatinib in osteosarcoma. The primary goal of this study was to examine the inhibitory effectiveness and mechanism of lenvatinib on the growth and invasion of OS cells. MATERIALS AND METHODS: The effects of lenvatinib on cell viability, apoptosis, protein kinase B (AKT) activation, its downstream effector proteins involved in tumor progression, and invasion capability were assessed using MTT assay, flow cytometry, western blotting, and invasion/migration assay on U-2 OS and MG63 cells. RESULTS: Lenvatinib effectively induced cytotoxicity, apoptosis, as well as extrinsic and intrinsic apoptotic signaling in OS cells. Lenvatinib also significantly decreased the invasion/migration capability, AKT activation, and downstream effector proteins. CONCLUSION: The anti-OS effect of lenvatinib may be associated with the induction of apoptosis and the inactivation of AKT.

Let-7g Upregulation Attenuated the KRAS-PI3K-Rac1-Akt Axis-Mediated Bioenergetic Functions.

The aberrant activation of signaling pathways contributes to cancer cells with metabolic reprogramming. Thus, targeting signaling modulators is considered a potential therapeutic strategy for cancer. Subcellular fractionation, coimmunoprecipitation, biochemical analysis, and gene manipulation experiments revealed that decreasing the interaction of kirsten rat sarcoma viral oncogene homolog (KRAS) with p110α in lipid rafts with the use of naringenin (NGN), a citrus flavonoid, causes lipid raft-associated phosphatidylinositol 3-kinase (PI3K)-GTP-ras-related C3 botulinum toxin substrate 1 (Rac1)-protein kinase B (Akt)-regulated metabolic dysfunction of glycolysis and mitochondrial oxidative phosphorylation (OXPHOS), leading to apoptosis in human nasopharyngeal carcinoma (NPC) cells. The use of lethal-7g (let-7g) mimic and let-7g inhibitor confirmed that elevated let-7g resulted in a decrease in KRAS expression, which attenuated the PI3K-Rac1-Akt-BCL-2/BCL-xL-modulated mitochondrial energy metabolic functions. Increased let-7g depends on the suppression of the RNA-specificity of monocyte chemoattractant protein-induced protein-1 (MCPIP1) ribonuclease since NGN specifically blocks the degradation of pre-let-7g by NPC cell-derived immunoprecipitated MCPIP1. Converging lines of evidence indicate that the inhibition of MCPIP1 by NGN leads to let-7g upregulation, suppressing oncogenic KRAS-modulated PI3K-Rac1-Akt signaling and thereby impeding the metabolic activities of aerobic glycolysis and mitochondrial OXPHOS.

Automatic Detection of Putative Mild Cognitive Impairment from Speech Acoustic Features in Mandarin-Speaking Elders.

BACKGROUND: To date, the reliable detection of mild cognitive impairment (MCI) remains a significant challenge for clinicians. Very few studies investigated the sensitivity of acoustic features in detecting Mandarin-speaking elders at risk for MCI, defined as "putative MCI" (pMCI). OBJECTIVE: This study sought to investigate the possibility of using automatically extracted speech acoustic features to detect elderly people with pMCI and reveal the potential acoustic markers of cognitive decline at an early stage. METHODS: Forty-one older adults with pMCI and 41 healthy elderly controls completed four reading tasks (syllable utterance, tongue twister, diadochokinesis, and short sentence reading), from which acoustic features were extracted automatically to train machine learning classifiers. Correlation analysis was employed to evaluate the relationship between classifier predictions and participants' cognitive ability measured by Mini-Mental State Examination 2. RESULTS: Classification results revealed that some temporal features (e.g., speech rate, utterance duration, and the number of silent pauses), spectral features (e.g., variability of F1 and F2), and energy features (e.g., SD of peak intensity and SD of intensity range) were effective predictors of pMCI. The best classification result was achieved in the Random Forest classifier (accuracy = 0.81, AUC = 0.81). Correlation analysis uncovered a strong negative correlation between participants' cognitive test scores and the probability estimates of pMCI in the Random Forest classifier, and a modest negative correlation in the Support Vector Machine classifier. CONCLUSIONS: The automatic acoustic analysis of speech could provide a promising non-invasive way to assess and monitor the early cognitive decline in Mandarin-speaking elders.

The Presence of Diabetes Mellitus or Pre-diabetes Mellitus Increases Mortality from Heart Disease in a Taiwanese Population: A 10-year Follow-Up Study.

BACKGROUND: We evaluated hyperglycemia-associated mortality in the Taiwanese population by conducting a 10-year retrospective cohort study. METHODS: From 2007 to 2017, all participants, regardless of their age or underlying diseases, were identified at a Health Screening Center in Taiwan. Overall, 114,534 participants were included in the analysis. They were classified into three subgroups according to glycemia and smoking status by combining survival for data analysis. RESULTS: The mean follow-up time, age, and body mass index (BMI) were 8.14 ± 2.22 years, 40.95 ± 12.14 years, and 23.24 ± 3.65 kg/m2, respectively. The cumulative death rate increased from 0.9% in the normal fasting blood glucose(FBG) subgroup to approximately 6% in the diabetes FBG subgroup. After adjusting for age, gender, BMI, high-density lipoprotein, triglycerides, waist circumference(WC), and smoking status, the hazard ratio (HR) for all-cause, cancer, and heart disease mortality in the diabetes mellitus(DM) subgroup was 1.560, 1.381, and 1.828, respectively.HR was 0.989 in all-cause, 0.940 in cancer, and 1.326 in heart disease in the pre-DM subgroup. CONCLUSION: Being tested for pre-DM is related to a higher risk of death from heart disease in the Taiwanese population at baseline. Therefore, cardiovascular risk must be actively measured among diabetes patients every visit.

Verifying the accuracy of self-reported smoking behavior in female volunteer soldiers.

Smoking rates in the military are evaluated through questionnaire surveying. Because the accurate identification of smokers facilitates the provision of smoking cessation services, this study conducted urine cotinine concentration testing to verify the accuracy of self-reported smoking behavior by female volunteer soldiers and analyzed the effects of second-hand smoking on urine cotinine concentrations. This study is a cross-sectional study conducted using purposive sampling on female volunteer soldiers receiving training at the Taichung Recruit Training Center in May 2014. This study simultaneously collected questionnaires and urine samples, and urine samples were analyzed with an enzyme-linked immunosorbent assay. The self-reported smoking rate of female volunteer soldiers was 19.3%, whereas the smoking rate as determined by urine cotinine concentration testing was 26.3%, indicating an overall underestimation of 7.0%. Chi-square (χ2) goodness of fit test results indicated that the distribution of self-reported smoking behaviors and that verified from urine cotinine concentration testing were significantly different. The sensitivity of self-reported smoking behavior was 66.7% with a specificity of 97.6%. There was no significant association between second-hand smoking and urine cotinine concentrations. Questionnaire survey self-reporting methods could underestimate the smoking behavior of female volunteer soldiers and routine testing with biochemical verification is necessary.

Risk of Metachronous Advanced Colorectal Neoplasia After Removal of Diminutive Versus Small Nonadvanced Adenomas: A Multicenter Study.

BACKGROUND: Current postpolypectomy guidelines treat 1-9 mm nonadvanced adenomas (NAAs) as carrying the same level of risk for metachronous advanced colorectal neoplasia (ACRN). AIMS: To evaluate whether small (6-9 mm) NAAs are associated with a greater risk of metachronous ACRN than diminutive (1-5 mm) NAAs. METHODS: We retrospectively evaluated 10,060 index colonoscopies performed from July 2011 to June 2019. A total of 1369 patients aged ≥ 40 years with index NAAs and having follow-up examinations were categorized into 5 groups based on size and number of index findings: Group 1, ≤ 2 diminutive NAAs (n = 655); Group 2, ≤ 2 small NAAs (n = 529); Group 3, 3-4 diminutive NAAs (n = 78); Group 4, 3-4 small NAAs (n = 65); and Group 5, 5-10 NAAs (n = 42). Size was classified based on the largest NAA. ACRN was defined as finding an advanced adenoma or colorectal cancer at follow-up. RESULTS: The absolute risk of metachronous ACRN increased from 7.2% in patients with all diminutive NAAs to 12.2% in patients with at least 1 small NAA (P = 0.002). Patients in Group 2 (adjusted odds ratio [AOR] 1.89; 95% confidence interval [CI], 1.21-2.95), Group 3 (AOR 2.40; 95% CI 1.78-4.90), Group 4 (AOR 2.77; 95% CI 1.35-5.66), and Group 5 (AOR 3.71; 95% CI 1.65-8.37) were associated with an increased risk of metachronous ACRN compared with Group 1. CONCLUSIONS: Patients with small NAAs have an increased risk of metachronous ACRN. Postpolypectomy guidelines should consider including risk stratification between small and diminutive adenomas.

Older Age and High α-Fetoprotein Predict Higher Risk of Hepatocellular Carcinoma in Chronic Hepatitis-B-Related Cirrhotic Patients Receiving Long-Term Nucleos(t)ide Analogue Therapy.

Background: Nucleos(t)ide analogues (NUCs) were proved to reduce hepatocellular carcinoma (HCC) development in chronic hepatitis B (CHB) patients, but data were limited on their efficacy in cirrhotic CHB patients. Methods: A total of 447 cirrhotic CHB patients treated with tenofovir/entecavir were retrospectively analyzed and divided into HCC (n = 48) and non-HCC (n = 399) groups. The median follow-up period was 62.1 months. Results: A total of 48 patients (10.7%) developed HCC during surveillance. The annual incidence rate of HCC was 2.04 per 100 person-years. The cumulative incidence of HCC was 0.9%, 9.8%, and 22.1% at 1, 5, and 10 years, respectively. Significant predictors for HCC identified using a multiple Cox regression analysis were age ≥50 years (hazard ratio (HR): 2.34) and α-fetoprotein (AFP) ≥8 ng/mL (HR: 2.05). The incidence rate of HCC was 8.67-fold higher in patients with age ≥50 years and AFP ≥8 ng/mL (3.14 per 100 person-years) than those with age <50 years and AFP <8 ng/mL (0.36 per 100 person-years). Conclusions: Cirrhotic CHB patients with age <50 years and AFP <8 ng/mL had the lowest annual incidence of HCC. However, those with age ≥50 years or/and AFP ≥8 ng/mL had a significantly higher risk for HCC development and warrant a careful surveillance schedule.

Stress-induced higher vein density in the C3-C4 intermediate Moricandia suffruticosa under drought and heat stress.

The evolution of C4 photosynthesis involved multiple anatomical and physiological modifications, yet our knowledge of the genetic regulation involved remains elusive. In this study, systematic analyses were conducted comparing the C3-C4 intermediate Moricandia suffruticosa and its C3 relative Brassica napus (rapeseed). We found that the leaves of M. suffruticosa had significantly higher vein density than those of B. napus, and the vein density was further increased in M. suffruticosa under drought and heat stress. Moreover, the bundle sheath distance, as the mean distance from the outer wall of one bundle sheath to the outer wall of an adjacent one, decreased and the number of centripetal chloroplasts in bundle sheath cells was found to be altered in M. suffruticosa leaves under drought and heat treatments. These results suggest that abiotic stress can induce a change in an intermediate C3-C4 anatomy towards a C4-like anatomy in land plants. By integrating drought and heat factors, co-expression network and comparative transcriptome analyses between M. suffruticosa and B. napus revealed that inducible auxin signaling regulated vascular development, and autophagy-related vesicle trafficking processes were associated with this stress-induced anatomical change. Overexpressing three candidate genes, MsERF02, MsSCL01, and MsDOF01, increased leaf vein density and/or enhanced photosynthetic assimilation and drought adaptability in the transgenic lines. The findings of this study may improve our understanding of the genetic regulation and evolution of C4 anatomy.

The Association between Serum Testosterone and Hyperuricemia in Males.

Gout is a common systemic inflammatory disease with a male predominance. This study aimed to determine the relationship between serum total testosterone level and hyperuricemia. Data on 1899 men, collected from 2007 to 2017, were included in the analysis. Serum testosterone and urate (SU) were measured on enrolment. The primary endpoints were SU levels ≥ 7 mg/dL and ≥9 mg/dL. On enrolment, participants had a mean age of 45.6 years and mean total testosterone and SU levels of 510 ng/dL and 6.6 mg/dL, respectively. The mean total testosterone levels were 533 and 470 ng/dL in patients with SU levels < 7 mg/dL and ≥7 mg/dL, respectively (p < 0.001); and 515 and 425 ng/dL in patients with SU levels < 9 mg/dL and ≥9 mg/dL, respectively (p < 0.001). After adjusting for age, body mass index, creatinine, serum lipid, fasting blood glucose, systolic blood pressure, and diastolic blood pressure, low testosterone level (<400 ng/dL) was significantly associated with an SU level ≥ 7 mg/dL (hazard ratio: 1.182, 95% confidence interval: 1.005−1.39) and ≥9 mg/dL (hazard ratio: 1.905, 95% confidence interval: 1.239−2.928). In men, a low testosterone level may be associated with an increased risk of hyperuricemia.

Anti-Oxidative Effect of Pu-erh Tea in Animals Trails: A Systematic Review and Meta-Analysis.

This study adopted systematic literature review and meta-analysis methodology to explored anti-oxidative effect of pu-erh tea. Study authors have systemically searched seven databases up until 21 February 2020. In performing the literature search on the above-mentioned databases, the authors used keywords of pu-erh AND (superoxide dismutase OR glutathione peroxidase OR malondialdehyde). Results derived from meta-analyses showed statistically significant effects of pu-erh tea on reducing serum MDA levels (SMD, −4.19; 95% CI, −5.22 to −3.15; p < 0.001; I2 = 93.67%); increasing serum SOD levels (SMD, 2.41; 95% CI, 1.61 to 3.20; p < 0.001; I2 = 91.36%); and increasing serum GSH-Px levels (SMD, 4.23; 95% CI, 3.10 to 5.36; p < 0.001; I2 = 93.69%). Results from systematic review and meta-analyses validated that various ingredients found in pu-erh tea extracts had anti-oxidation effects, a long-held conventional wisdom with limited supporting evidence.

Phase Separation Behavior of Aqueous Poly(N-isopropylacrylamide) Solutions Studied by Scattering Experiments.

We have investigated the colloidal phase-separating dilute solution of aqueous poly(N-isopropylacrylamide) (PNIPAM) with a molecular weight of 1.24 × 105 by small-angle X-ray scattering (SAXS) as well as static and dynamic light scattering (SLS and DLS). Those scattering experiments provide us with the average size and size distribution of concentrated-phase droplets and the concentration cconc of the coexisting concentrated phase. While the average droplet size is almost constant above 35 °C in the temperature-scan experiments, it is a decreasing function of temperature above 35 °C in the temperature-jump experiments. This heating rate dependence of the average droplet size arises from the fact that concentrated-phase droplets in the aqueous PNIPAM solution grow only in a limited temperature range (31.5-35 °C). The scattering results on the temperature dependence of cconc are combined with previously reported results of turbidity and DSC, giving the phase diagram of the Type II phase behavior with the off-zero critical point at high molecular weight.

Procedure-related risk factors for bleeding after percutaneous transhepatic biliary drainage: A systematic review and meta-analysis.

BACKGROUND/PURPOSE: Bleeding is the most dreaded complication after percutaneous transhepatic biliary drainage (PTBD). Clarifying the risk factors of bleeding can reduce the morbidity and mortality rates of PTBD. However, the procedure-related risk factors for bleeding after PTBD are still controversial. Therefore, this systematic review and meta-analysis were performed to identify procedure-related risk factors of bleeding after PTBD. METHODS: PubMed, Cochrane database, and Google Scholar were searched for published studies until 1st May 2021. Inclusion criteria were: studies associated with bleeding complications after PTBD and with sufficient data to compare different procedure-related factors for bleeding. Sources of bias were assessed using the Newcastle-Ottawa Scale and Cochrane risk-of-bias tool for randomised trials. Probable procedure-related risk factors were evaluated and outcomes were expressed in the case of dichotomous variables, as an odds ratio (OR) (with a 95% confidence interval, (CI)). RESULTS: Eleven studies were included in the meta-analysis. There was no significant difference in bleeding rates with respect to the side of PTBD (left/right, OR = 1.10, 95% CI: 0.68-1.76), the insertion level of bile duct (central/peripheral, OR = 1.39, 95% CI: 0.82-2.35), and the usage of ultrasound guidance (OR: 1.25, 95% CI: 0.60-2.60). A subgroup analysis revealed a left-sided approach that resulted in more hepatic arterial injuries than the right-sided approach (left/right, OR = 1.93, 95% CI: 1.32-2.83). CONCLUSION: Left-sided approach is a risk factor for hepatic arterial injuries after PTBD.

Overexpression of Cell-Surface Marker SLC16A1 Shortened Survival in Human High-Grade Gliomas.

Solute carrier family 16 member 1 (SLC16A1) is a crucial transcription factor in modifying cancer progression and metastasis. However, its character in defining the clinical prognosis of human gliomas has not been illuminated. In our analysis from PREdiction of Clinical Outcomes from Genomic Profiles (PRECOG), The Cancer Genome Atlas (TCGA), and Chinese Glioma Genome Atlas (CGGA), we found that SLC16A1 mRNA expression level was significantly increased in high-grade gliomas in contrast to low-grade gliomas and non-tumor controls (P < 0.05). Kaplan-Meier analysis of four independent cohort studies from the Gene Expression Omnibus (GEO) profile, TCGA, and CGGA which consistently presented patients with high SLC16A1 mRNA expression displayed poor overall survival in high-grade glioma patients (P < 0.05 by log-rank test). Based on the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING), the protein-protein interaction analysis of SLC16A1-regulated oncogenesis showed SLC16A1 as a potential hub protein. Immunohistochemical staining exhibited that SLC16A1 protein overexpressed in high-grade gliomas compared with low-grade clinical glioma samples. All these findings suggest that SLC16A1 expression has a positive correlation with WHO pathological grading and poor survival. SLC16A1 might be a potential biomarker of prognosis in human gliomas.

Genome-Wide Identification and Evolutionary Analysis of the Fruit-Weight 2.2-Like Gene Family in Polyploid Oilseed Rape (Brassica napus L.).

The fruit-weight 2.2 (fw2.2) locus, which was first described in tomato, is known for controlling up to 30% of fruit mass. The functions of its homologs, the FW2.2-like (FWL) genes, have also been documented in other diploid plants such as maize and rice. However, the evolution and contribution of the FWL gene family to seed weight in polyploid crops remain to be explored. In this study, we deployed an integrated approach to characterize the FWL gene family in the allotetraploid crop, Brassica napus. A total of 18 FWL genes were identified and designated BnFWL1-18. These were classified into three groups based on their phylogenetic relationships, which were supported by multiple sequence alignment, chromosome location, collinearity, transmembrane prediction, conserved motifs, selection pressure, protein three-dimensional (3D) structure, and the composition and position of cis-regulatory elements. Strikingly, three conserved 3D models were identified in all 18 BnFWL proteins, pertaining to the soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex. Intriguingly, we found that the BnFWL12 protein was structurally similar to phosphoenolpyruvate carboxylase, which is required for photosynthesis. More importantly, we identified an "SDGE" phosphorylation motif in BnFWL12 in a search for putative casein kinase II (CK2) phosphorylation sites. Moreover, the temporospatial expression profiles in different tissues revealed that the discrete expression patterns are likely associated with the functional differentiation of BnFWL genes. Taken together, our data shed light on the evolutionary divergence of the FWL gene family in a polyploid crop, providing foundations for further functional studies.

Inhibitory effects of pu-erh tea on alpha glucosidase and alpha amylase: a systemic review.

OBJECTIVE: Pu-erh tea was presumed to have anti-hyperglycemic effects via inhibition on alpha-amylase and alpha-glucosidase. However, no integerated literatures were published to substantiate such presumption. METHODS: Current study adopted systemic review method to validate inhibitory effects on alpha amylase and alpha-glucosidase. Five English databases (PubMed, EBSCO, SCOPUS, Cochrane Library, Web of Science) and three Chinese ones (Airti Library, CNKI Library, and Google Scholar) were searched up to 22 March 2018 for eligible literatures, using keywords of Pu-erh, Pu'er, alpha-amylase or alpha-glucosidase. RESULTS: Six studies exploring inhibitory effects on alpha-glucosidase and seven on alpha-amylase were included for systemic review. Though results showed pu-erh tea has significant inhibitory effects on alpha-amylase and alpha-glucosidase, high heterogeneity was detected among studies included. CONCLUSIONS: High heterogeneity may be due to complex alterations of chemicals under different degrees of fermentation. More future studies are required to further identify principal bioactive component(s) at work.

Citrate-Induced p85α⁻PTEN Complex Formation Causes G2/M Phase Arrest in Human Pharyngeal Squamous Carcinoma Cell Lines.

Citrate is a key intermediate of the tricarboxylic acid cycle and acts as an allosteric signal to regulate the production of cellular ATP. An elevated cytosolic citrate concentration inhibits growth in several types of human cancer cells; however, the underlying mechanism by which citrate induces the growth arrest of cancer cells remains unclear. The results of this study showed that treatment of human pharyngeal squamous carcinoma (PSC) cells with a growth-suppressive concentration of citrate caused cell cycle arrest at the G2/M phase. A coimmunoprecipitation study demonstrated that citrate-induced cell cycle arrest in the G2/M phase was associated with stabilizing the formation of cyclin B1-phospho (p)-cyclin-dependent kinase 1 (CDK1) (Thr 161) complexes. The citrate-induced increased levels of cyclin B1 and G2/M phase arrest were suppressed by the caspase-3 inhibitor Ac-DEVD-CMK and caspase-3 cleavage of mutant p21 (D112N). Ectopic expression of the constitutively active form of protein kinase B (Akt1) could overcome the induction of p21 cleavage, cyclin B1-p-CDK1 (Thr 161) complexes, and G2/M phase arrest by citrate. p85α-phosphatase and tensin homolog deleted from chromosome 10 (PTEN) complex-mediated inactivation of Akt was required for citrate-induced G2/M phase cell cycle arrest because PTEN short hairpin RNA or a PTEN inhibitor (SF1670) blocked the suppression of Akt Ser 473 phosphorylation and the induction of cyclin B1-p-CDK1 (Thr 161) complexes and G2/M phase arrest by citrate. In conclusion, citrate induces G2/M phase arrest in PSC cells by inducing the formation of p85α-PTEN complexes to attenuate Akt-mediated signaling, thereby causing the formation of cyclin B1-p-CDK1 (Thr 161) complexes.

Important photosynthetic contribution of silique wall to seed yield-related traits in Arabidopsis thaliana.

In plants, green non-foliar organs are able to perform photosynthesis just as leaves do, and the seed-enclosing pod acts as an essential photosynthetic organ in legume and Brassica species. To date, the contribution of pod photosynthesis to seed yield and related components still remains largely unexplored, and in Arabidopsis thaliana, the photosynthetic activity of the silique (pod) is unknown. In this study, an Arabidopsis glk1/glk2 mutant defective in both leaf and silique photosynthesis was used to create tissue-specific functional complementation lines. These lines were used to analyze the contribution of silique wall photosynthesis to seed yield and related traits, and to permit the comparison of this contribution with that of leaf photosynthesis. Our results showed that, together with leaves, the photosynthetic assimilation of the silique wall greatly contributed to total seed yield per plant. As for individual components of yield traits, leaf photosynthesis alone contributed to the seed number per silique and silique length, while silique wall photosynthesis alone contributed to thousand-seed weight. In addition, enhancing the photosynthetic capacity of the silique wall by overexpressing the photosynthesis-related RCA gene in this tissue resulted in significantly increased seed weight and oil content in the wild-type (WT) background. These results reveal that silique wall photosynthesis plays an important role in seed-related traits, and that enhancing silique photosynthesis in WT plants can further improve seed yield-related traits and oil production. This finding may have significant implications for improving the seed yield and oil production of oilseed crops and other species with pod-like organs.

Suppression of Akt-mediated HDAC3 expression and CDK2 T39 phosphorylation by a bichalcone analog contributes to S phase retardation of cancer cells.

Targeting cell cycle regulators has been a suggested mechanism for therapeutic cancer strategies. We report here that the bichalcone analog TSWU-CD4 induces S phase arrest of human cancer cells by inhibiting the formation of cyclin A-phospho (p)-cyclin-dependent kinase 2 (CDK2, threonine [Thr] 39) complexes, independent of mutant p53 expression. Ectopic expression of CDK2 (T39E), which mimics phosphorylation of the Thr 39 residue of CDK2, partially rescues the cells from TSWU-CD4-induced S phase arrest, whereas phosphorylation-deficient CDK2 (T39A) expression regulates cell growth with significant S phase arrest and enhances TSWU-CD4-triggered S phase arrest. Decreased histone deacetylase 3 (HDAC3) expression after TSWU-CD4 treatment was demonstrated, and TSWU-CD4 induced S phase arrest and inhibitory effects on cyclin A expression and CDK2 Thr 39 phosphorylation, while cyclin A-p-CDK2 (Thr 39) complex formation was suppressed by ectopic wild-type HDAC3 expression. The co-transfection of CDK2 (T39E) along with HDAC3 completely restored cyclin A expression, Thr 39-phosphorylated CDK2, cyclin A-p-CDK2 (Thr 39) complex formation, and the S phase population to normal levels. Protein kinase B (Akt) inactivation was required for TSWU-CD4-induced S phase cell cycle arrest, because constitutively active Akt1 blocks the induction of S phase arrest and the suppression of cyclin A and HDAC3 expression, CDK2 Thr 39 phosphorylation, and cyclin A-p-CDK2 (Thr 39) complex formation by TSWU-CD4. Taken together, our results indicate that TSWU-CD4 induces S phase arrest by inhibiting Akt-mediated HDAC3 expression and CDK2 Thr 39 phosphorylation to suppress the formation of cyclin A-p-CDK2 (Thr 39) complexes.