Numerical Analysis and Quantification of Transfer Efficiency Coupled with Capillary and Quadrupole Ion Guide in an API-MS System.

Ion trajectory simulation is a significant and useful tool for understanding ion transfer mechanisms within the first vacuum region of the atmospheric pressure ionization mass spectrometer (API-MS). However, the complex dynamic gas field and wide pressure range lead to inaccurate simulation and huge computational costs. In this work, a novel electrohydrodynamic simulation called the statistical diffusion-hard-sphere (SDHS) mixed collision model was developed for characterizing the ion trajectories. For the first time, the influence of the dynamic pressure on the ion trajectory is considered for simulation, which helps to avoid an intolerable computational cost. Comparing with the conventional Monte Carlo collision model, the SDHS method helps to improve the calculation accuracy of ion trajectories under the first vacuum region and reduce the computational cost for at least 12-folds. Simulation results showed that the maximum ion loss came from the gap of the electrodes. The distance of the capillary-quadrupole ion guide was also a non-negligible factor. The trend of quantitative experimental results matches the SDHS simulation results. The maximum ion transfer efficiencies of quantitative experiment and simulation were 55% and 52%, respectively. Moreover, three ions, caffeine, reserpine, and Ultramark 1621, were measured for evaluating the applicability of SDHS in real API-MS. The trend of experimental results showed good agreement with that of computation. And the results of caffeine further illustrated the reason that the small mass ion transfer efficiency decreased with increasing radio frequency voltage. SDHS method is expected to be useful in the design of ion guides for further improvement of the sensitivity of API-MS.

Harnessing landrace diversity empowers wheat breeding.

Harnessing genetic diversity in major staple crops through the development of new breeding capabilities is essential to ensure food security1. Here we examined the genetic and phenotypic diversity of the A.E. Watkins landrace collection2 of bread wheat (Triticum aestivum), a major global cereal, through whole-genome re-sequencing (827 Watkins landraces and 208 modern cultivars) and in-depth field evaluation spanning a decade. We discovered that modern cultivars are derived from just two of the seven ancestral groups of wheat and maintain very long-range haplotype integrity. The remaining five groups represent untapped genetic sources, providing access to landrace-specific alleles and haplotypes for breeding. Linkage disequilibrium (LD) based haplotypes and association genetics analyses link Watkins genomes to the thousands of high-resolution quantitative trait loci (QTL), and significant marker-trait associations identified. Using these structured germplasm, genotyping and informatics resources, we revealed many Watkins-unique beneficial haplotypes that can confer superior traits in modern wheat. Furthermore, we assessed the phenotypic effects of 44,338 Watkins-unique haplotypes, introgressed from 143 prioritised QTL in the context of modern cultivars, bridging the gap between landrace diversity and current breeding. This study establishes a framework for systematically utilising genetic diversity in crop improvement to achieve sustainable food security.

Development of a next generation SNP genotyping array for wheat.

High-throughput genotyping arrays have provided a cost-effective, reliable and interoperable system for genotyping hexaploid wheat and its relatives. Existing, highly cited arrays including our 35K Wheat Breeder's array and the Illumina 90K array were designed based on a limited amount of varietal sequence diversity and with imperfect knowledge of SNP positions. Recent progress in wheat sequencing has given us access to a vast pool of SNP diversity, whilst technological improvements have allowed us to fit significantly more probes onto a 384-well format Axiom array than previously possible. Here we describe a novel Axiom genotyping array, the 'Triticum aestivum Next Generation' array (TaNG), largely derived from whole genome skim sequencing of 204 elite wheat lines and 111 wheat landraces taken from the Watkins 'Core Collection'. We used a novel haplotype optimization approach to select SNPs with the highest combined varietal discrimination and a design iteration step to test and replace SNPs which failed to convert to reliable markers. The final design with 43 372 SNPs contains a combination of haplotype-optimized novel SNPs and legacy cross-platform markers. We show that this design has an improved distribution of SNPs compared to previous arrays and can be used to generate genetic maps with a significantly higher number of distinct bins than our previous array. We also demonstrate the improved performance of TaNGv1.1 for Genome-wide association studies (GWAS) and its utility for Copy Number Variation (CNV) analysis. The array is commercially available with supporting marker annotations and initial genotyping results freely available.

Two sex pheromone receptors for sexual communication in the American cockroach.

Volatile sex pheromones are vital for sexual communication between males and females. Females of the American cockroach, Periplaneta americana, produce and emit two sex pheromone components, periplanone-A (PA) and periplanone-B (PB). Although PB is the major sex attractant and can attract males, how it interacts with PA in regulating sexual behaviors is still unknown. In this study, we found that in male cockroaches, PA counteracted PB attraction. We identified two odorant receptors (ORs), OR53 and OR100, as PB/PA and PA receptors, respectively. OR53 and OR100 were predominantly expressed in the antennae of sexually mature males, and their expression levels were regulated by the sex differentiation pathway and nutrition-responsive signals. Cellular localization of OR53 and OR100 in male antennae further revealed that two types of sensilla coordinate a complex two-pheromone-two-receptor pathway in regulating cockroach sexual behaviors. These findings indicate distinct functions of the two sex pheromone components, identify their receptors and possible regulatory mechanisms underlying the male-specific and age-dependent sexual behaviors, and can guide novel strategies for pest management.

Rational design of an iminocoumarin-based fluorescence probe for peroxynitrite with high signal-to-noise ratio.

As a high reactive oxygen species (ROS) and a reactive nitrogen species (RNS), peroxynitrite anion (ONOO- ) is widely present in organisms and plays influential roles in physiological and pathological processes. It is of great significance to develop effective fluorescent probes for imaging peroxynitrite variation in living systems. Herein we present a novel fluorescent probe TQC0 for monitoring ONOO- based on the iminocoumarin platform, and this probe was synthesized by the knoevenagel condensation between a dihydropyridine-salicylaldehyde derivative and 2-benzothiazole-acetonitrile, and subsequently masked with the boronate moiety. The obtained probe TQC0 exhibited a high signal-to-noise ratio (206-fold) and a quick 'turn-on' response (about 10 min) with great selectivity and sensitivity. Furthermore, the probe TQC0 was successfully applied for imaging ONOO- in living cells with low cytotoxicity.

Quantification of 25OHD in serum by ID-LC-MS/MS based on oriented immobilization of antibody on magnetic materials.

Magnetic nanomaterials are widely used, but co-adsorption of impurities will lead to saturation. In this study, the aim was to prepare a magnetic nano-immunosorbent material based on orienting immobilization that can purify and separate 25-hydroxyvitamin D (25OHD) from serum and provides a new concept of sample pretreatment technology. Streptococcus protein G (SPG) was modified on the surface of the chitosan magnetic material, and the antibody was oriented immobilized using the ability of SPG to specifically bind to the Fc region of the monoclonal antibody. The antigen-binding domain was fully exposed and made up for the deficiency of the antibody random immobilization. Compared with the antibody in the random binding format, this oriented immobilization strategy can increase the effective activity of the antibody, and the amount of antibody consumed is saved to a quarter of the former. The new method is simple, rapid, and sensitive, without consuming a lot of organic reagents, and can enrich 25OHD after simple protein precipitation. Combining with liquid chromatography-tandem mass spectrometry (LC-MS/MS), the analysis can be completed in less than 30 min. For 25OHD2 and 25OHD3, the LOD was 0.021 and 0.017 ng mL-1, respectively, and the LOQ was 0.070 and 0.058 ng mL-1, respectively. The results indicated that the magnetic nanomaterials based on oriented immobilization can be applied as an effective, sensitive, and attractive adsorbent to the enrichment of serum 25OHD.

Quantitative Detection of Natural Rubber Content in Eucommia ulmoides by Portable Pyrolysis-Membrane Inlet Mass Spectrometry.

Eucommia ulmoides gum (EUG) is a natural polymer predominantly consisting of trans-1,4-polyisoprene. Due to its excellent crystallization efficiency and rubber-plastic duality, EUG finds applications in various fields, including medical equipment, national defense, and civil industry. Here, we devised a portable pyrolysis-membrane inlet mass spectrometry (PY-MIMS) approach to rapidly, accurately, and quantitatively identify rubber content in Eucommia ulmoides (EU). EUG is first introduced into the pyrolyzer and pyrolyzed into tiny molecules, which are then dissolved and diffusively transported via the polydimethylsiloxane (PDMS) membrane before entering the quadrupole mass spectrometer for quantitative analysis. The results indicate that the limit of detection (LOD) for EUG is 1.36 µg/mg, and the recovery rate ranges from 95.04% to 104.96%. Compared to the result of pyrolysis-gas chromatography (PY-GC), the average relative error is 1.153%, and the detection time was reduced to less than 5 min, demonstrating that the procedure was reliable, accurate, and efficient. The method has the potential to be employed to precisely identify the rubber content of natural rubber-producing plants such as Eucommia ulmoides, Taraxacum kok-saghyz (TKS), Guayule, and Thorn lettuce.

Zwitterionic rhodamine-CPT prodrug nanoparticles with GSH/H2O2 responsiveness for cancer theranostics.

Rationale: Fluorescently traceable prodrugs, which can monitor their biodistribution in vivo and track the kinetics of drug delivery in living cells, are promising for constructing theranostic medicines. However, due to their charge and hydrophobicity, most of the fluorescently traceable prodrugs exhibit high protein binding and non-specific tissue retention affecting in vivo distribution and toxicity, with high background signals. Methods: Herein, the zwitterionic rhodamine (RhB) and camptothecin (CPT) were bridged with a disulfide bond to construct a tumorous heterogeneity-activatable prodrug (RhB-SS-CPT). The interaction of zwitterionic RhB-SS-CPT with proteins was detected by UV and fluorescence spectroscopy, and further demonstrated by molecular docking studies. Then, intracellular tracking and cytotoxicity of RhB-SS-CPT were determined in tumor and normal cells. Finally, the in vivo biodistribution, pharmacokinetics, and anticancer efficacy of RhB-SS-CPT were evaluated in a mouse animal model. Results: The tumorous heterogeneity-activatable RhB-SS-CPT prodrug can self-assemble into stable nanoparticles in water based on its amphiphilic structure. Particularly, the zwitterionic prodrug nanoparticles reduce the non-specific binding to generate a low background signal for better identification of cancerous lesions, achieve rapid internalization into cancer cells, selectively release bioactive CPT as a cytotoxic agent in response to high levels of GSH and H2O2, and exhibit high fluorescence that contributes to the visual chemotherapy modality. In addition, the RhB-SS-CPT prodrug nanoparticles show longer circulation time and better antitumor activity than free CPT in vivo. Interestingly, the zwitterionic nature allows RhB-SS-CPT to be excreted through the renal route, with fewer side effects. Conclusions: Zwitterionic features and responsive linkers are important considerations for constructing potent prodrugs, which provide some useful insights to design the next-generation of theranostic prodrugs for cancer.

Analysis of low-abundance molecules in complex matrices by quadrupole-linear ion trap mass spectrometry using a simultaneous fragmentation and accumulation strategy.

RATIONALE: Fast and sensitive analysis of low-abundance molecules in complex matrices has always been a challenge in chemical and biological applications. Mass spectrometry (MS) has been widely used in the fields of chemical and biological analysis due to its unparalleled specificity and sensitivity. However, the MS signals consistently deteriorate in the presence of matrices. Demands for more sensitive and efficient methods to analyze those low-abundance molecules in chemical and biological systems are in urgent need. METHODS: Based on a home-made quadrupole-linear ion trap (Q-LIT) mass spectrometer, a simultaneous fragmentation and accumulation strategy was developed to improve the sensitivity of the analysis for the low-abundance molecules in complex matrices. Ions were filtered by the quadrupole into the LIT. The precursor ions were fragmented and the product ions were isolated and accumulated in the LIT simultaneously. The fragmentation, isolation and accumulation processes were conducted at the same time. The accumulation time could be controlled to accumulate sufficient product ions. RESULTS: With this strategy, the signal intensity of targeted molecules could be increased by 2-8 times and by increasing the accumulation time, this could be further enhanced. Those interferences induced by isomers and matrices can be reduced by using our method. We further applied our method to the quantification and analysis of biological samples. Tryptic digested peptides of myoglobin (Mb) were successfully detected by our method. CONCLUSIONS: We have established a new method with great advantages in the detection of molecules in complex matrices. The application of this method promises better results in the bioanalytical area, especially for the analysis of substances in complex matrices in the future.

Erratum.

Overexpression of the tumor necrosis factor receptor-associated factor 4 (TRAF4) has been detected in many cancer types and is considered to foster tumor progression. However, the role of TRAF4 in hepatocellular carcinoma (HCC) remains elusive. In this study, we found that TRAF4 was highly expressed in HCC cell lines and HCC tissues compared with normal liver cell lines and adjacent noncancerous tissues. TRAF4 overexpression in HCC tissues was correlated with tumor quantity and vascular invasion. In vitro studies showed that TRAF4 was associated with HCC cell migration and invasion. An in vivo study verified that TRAF4 overexpression facilitated metastasis in nude mice. In addition, overexpressed TRAF4 promoted the phosphorylation of Akt and induced Slug overexpression, leading to downregulated E-cadherin and upregulated vimentin, while silencing TRAF4 moderated the phosphorylation of Akt and repressed the expression of Slug, which resulted in upregulated E-cadherin and downregulated vimentin. These effects were inversed after pretreatment of the PI3K/Akt inhibitor LY294002 or overexpression of constitutively active Akt1. Our study demonstrated that TRAF4 was involved in promoting HCC cell migration and invasion. The process was induced by the EMT through activation of the PI3K/Akt signaling pathway.

Reactions of Transition-Metal Carbyne Cations with Ethylene in the Gas Phase.

The reactions of iridium- and osmium-carbyne hydride cations [HIrCH]+ and [HOsCH]+ with ethylene have been studied using mass spectrometry with isotopic-labeling in the gas phase. The carbyne reactivity is compared with that of the rhodium, cobalt, and iron analogues [TMCH2]+ (TM = Fe, Co, and Rh), which were determined to have the carbene structures. Besides the cycloaddition/dehydrogenation reaction in forming the [TMC3H4]+ + H2 (TM = Ir and Os) products, a second reaction pathway producing the [TMC2H2]+ ion and CH4 via triple hydrogen atom transfer reactions to the carbyne carbon is observed to be the major channel. The latter channel is not observed in the rhodium, cobalt, and iron carbene cation reactions. Quantum-chemical calculations indicate that the distinct reactivity is not due to different initial structures of the reactants. Both reaction channels are predicted to be thermodynamically exothermic and kinetically facile for the carbyne cations, and the reactions proceed with the initial formation of a carbene intermediate via hydride-carbyne coupling. The latter channel is also exothermic but kinetically unfavorable for the rhodium, cobalt, and iron carbene cations.

Strong Acid Anions Significantly Increasing the Charge State of Proteins during Electrospray Ionization.

Regulation of protein's charge state in electrospray is of great importance to the analysis of proteins. Different methods have been developed so far to increase the charge state of proteins. In this work, we investigated the influence of different anions on the charge state of proteins. Both strong acid anions and weak acid anions were taken into consideration. The results showed that the presence of 5 mM strong acid anions in acidic solutions could significantly increase the charge state of proteins. In comparison, weak acid anions with the same concentration in solution had little impact on the charge state of proteins. The species of the cations in the samples had very limited influence on the charge state. The presence of a certain amount of acid in sample solution was critical to the effect of strong acid anions. Almost no increase of the charge state was observed when no acid was added to the samples. However, remarkable increase of the charge state of myoglobin (Mb) was observed when 0.001% (v/v) acetic acid (HAc) was added to the sample together with 5 mM sodium chloride (NaCl). A higher concentration of acid in samples would further enhance the effect of strong acid anions on the increase of the charge state. Further investigations into the mechanism revealed that the effect of the strong acid anions on the charge state of proteins was based on the unfolding of the protein molecules during electrospray ionization (ESI). The interactions among H+, anions, and protein molecules were so strong that it caused the unfolding of protein molecules and resulted in the increasing of proteins' charge states. The key factor that made strong acid anions and weak acid anions different in the results was the hydrolysis of the weak acid anions in acidic solutions. The present work furthers our understanding about electrospray, as well as the regulation of protein charge state. The presence of strong acid anions in acidic solutions can significantly influence the charge state of proteins in electrospray. Attention should be paid to this when regulating the charge state of proteins.

The role of circular RNA hsa_circ_0085616 in proliferation and migration of hepatocellular carcinoma cells.

BACKGROUND: CircRNAs involved in the development of many diseases have been recently identified. However, the possible role of circRNAs in human hepatocellular carcinoma (HCC) remains to be investigated. OBJECTIVE: This study aimed to identify the expression of hsa_circ_0085616 in different HCC cell lines and its function in HCC tumorigenesis. METHODS: The expression of hsa_circ_0085616 was first measured in 68 pairs of HCC tissues and matched normal adjacent tissues. Further analysis was performed in different HCC cell lines and human normal hepatic cell lines. Moreover, we down- or upregulated its expression by cell transfection in vitro. Cell proliferation, migration, invasion and apoptosis were measured, and proliferation-related signaling pathway proteins were also analyzed. RESULTS: We found that hsa_circ_0085616 was highly expressed in all HCC cell lines compared to the normal liver cell line. Upregulation or downregulation of hsa_circ_0085616 expression could strengthen or weaken the proliferative ability of HCC cells in vitro. Moreover, the protein levels of ß-catenin, p-ERK, and p-AKT, which play important roles in the typical proliferation pathway, were also affected by the expression of hsa_circ_0085616. CONCLUSION: Our study indicated that hsa_circ_0085616 might be a potential biomarker and a new therapeutic target for HCC.

Laparoscopic common bile duct exploration with primary closure is safe for management of choledocholithiasis in elderly patients.

BACKGROUND: Laparoscopic common bile duct exploration (LCBDE) is one of the minimally invasive options for choledocholithiasis. Primary closure of the common bile duct (CBD) upon completion of laparoscopic choledochotomy is safe in selected patients. The present study aimed to evaluate the feasibility and safety of primary closure of CBD after LCBDE in patients aged 70 years or older. METHODS: A total of 116 patients (51 males and 65 females) who suffered from choledocholithiasis and underwent primary closure of the CBD (without T-tube drainage) after LCBDE from January 2003 to December 2017 were recruited. They were classified into two groups according to age: group A (≥70 years, n = 56), and group B (<70 years, n = 60). The preoperative characteristics, intraoperative details, and postoperative outcomes of the two groups were evaluated. RESULTS: The mean operative time was 172.02 min for group A and 169.92 min for group B (P = 0.853). The mean hospital stay was 7.40 days for group A and 5.38 days for group B (P < 0.001). Bile leakage occurred in two patients in group A and one in group B (3.57% vs 1.67%, P = 0.952). There were no significant differences in the rates of postoperative complications and mortality between the two groups. At median follow-up time of 60 months, stone recurrence was detected in one patient in group A and two in group B (1.79% vs 3.33%, P = 1.000). Stenosis of CBD was not observed in group A and slight stenosis in one patient in group B (0 vs 1.67%, P = 1.000). CONCLUSION: Primary closure of the CBD upon completion of laparoscopic choledochotomy is safe and feasible in elderly patients ≥70 years old.

Perioperative and long-term outcomes of laparoscopic versus open liver resection for hepatocellular carcinoma with well-preserved liver function and cirrhotic background: a propensity score matching study.

BACKGROUND: Although laparoscopic liver resection (LLR) has advanced into a safe and effective alternative to conventional open liver resection (OLR), it has not been widely accepted by surgeons. This article aimed to investigate the perioperative and long-term benefits of LLR versus OLR for hepatocellular carcinoma (HCC) in selected patients with well-preserved liver function and cirrhotic background. METHODS: A retrospective study was conducted on 1085 patients with HCC who underwent liver resection at Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University from July 2010 to July 2015, and 346 patients with well-preserved liver function and cirrhotic background were selected. A 1:1 propensity score matching (PSM), which is the best option to overcome selection bias, was conducted to compare the surgical outcomes and long-term prognosis between LLR and OLR. After PSM, a logistic regression analysis was used to identify the predictive risk factors of posthepatectomy liver failure (PHLF). RESULTS: By using PSM, the two groups were well balanced with 86 patients in each group. In the LLR group, only the median operation time was significantly longer than the OLR group, but the hospital stay, overall morbidity, and the incidence of PHLF were significantly decreased compared to OLR. There were no significant differences in the overall survival and disease-free survival rates between the two groups. On multivariate analysis, OLR was identified to be the only independent risk factor for PHLF. CONCLUSIONS: In selected HCC patients with well-preserved liver function and cirrhotic background, LLR could be a better option compared to OLR.

Ultrasensitive analysis of heat shock protein 90α with antibodies orderly arrayed on a novel type of immunoprobe based on magnetic COFs.

The early diagnosis of liver cancer by target biomarkers is of great significance for improving the survival rate of cancer patients. However, it is still a challenging task to sensitively detect circulating protein biomarkers due to decreased binding activity of antibodies originating from uncontrolled orientation of immobilization on the surface of a solid matrix. In this work, a novel immunoaffinity probe, Fe3O4@TpBD-DSS-Ab-MEG, based on magnetic COFs with ordered arrangement of anchored antibodies has been developed and applied for the first time to detection of a cancer biomarker, heat shock protein 90alpha (Hsp90α). The fabricated composites possess favorable features from magnetic cores and COF shells, including strong magnetic responses (7.96 emu g-1), ordered active groups, a large amount of immobilized antibodies (111.7 µg/mg), good solvent and thermal stability. Fe3O4@TpBD-DSS-Ab-MEG demonstrated low detection limit (50 pg/mL), high selectivity (Hsp90α:BSA = 1:1000), desirable repeatability and good stability for Hsp90α immunocapture. Compared with other immunoprobes, our materials showed higher selectivity and sensitivity, which were mainly attributed to regular arrays of surface antibodies. Furthermore, samples containing Hsp90α at the concentration of 1 µg/mL in human plasma were used to test our immunoprobe, and 2 peptides of Hsp90α were successfully observed. The proposed non-invasive immunoassay strategy offers enhanced ability to control the orientation of immobilized antibodies and great promise for accurate analysis of the liver cancer biomarker Hsp90α in a complicated biological matrix. In addition, the facile preparation of magnetic COFs support and the satisfactory analytical performance made the newly developed immunoprobe a potential tool for sensitive detection of other cancer biomarkers in clinical diagnosis.

Laparoscopic liver re-resection is feasible for patients with posthepatectomy hepatocellular carcinoma recurrence: a propensity score matching study.

BACKGROUND: Liver re-resection plays a paramount role in treatment of patients with posthepatectomy hepatocellular carcinoma (HCC) recurrence. Laparoscopic liver resection has been a feasible alternative to open surgery. However, whether laparoscopic liver re-resection for posthepatectomy HCC recurrence is better than open liver re-resection remains unknown. METHOD: From January 2008 to December 2015, 30 patients with recurrent HCC after prior liver resection underwent laparoscopic liver re-resection in our center. To minimize any confounding factors, a propensity score matching study using a patient ratio of 1:1 was conducted to compare the short- and long-term outcomes of patients who underwent laparoscopic or open liver re-resection. RESULT: With the open surgery group compared laparoscopic group, operative time was 207.50 versus 200.5 min (p = 0.903), blood loss was 400 versus 100 ml (p = 0.000196), blood transfusion rate was 43.3 versus 0.0% (p = 0.000046), complication rates were 30.0 versus 6.7% (p = 0.01), and hospital stay was 13.5 versus 9.5 days (p = 0.000008). The median follow-up was 35 months. The 1-year, 3-year, 5-year disease-free survival rates were 79.0, 51.0, and 31.9%, versus 78.3, 57.4, and 43.0%, respectively (p = 0.474). The 1-year, 3-year, and 5-year overall survival rates were 89.4, 75, and 67.5%, versus 96.7, 85.0, and 74.4%, respectively (p = 0.413). CONCLUSION: Laparoscopic liver re-resection for patients with posthepatectomy HCC recurrence provided comparable perioperative and oncological outcomes as open liver re-resection and can be a safe alternative to open procedure.

TRAF4 Regulates Migration, Invasion, and Epithelial-Mesenchymal Transition via PI3K/AKT Signaling in Hepatocellular Carcinoma.

Overexpression of the tumor necrosis factor receptor-associated factor 4 (TRAF4) has been detected in many cancer types and is considered to foster tumor progression. However, the role of TRAF4 in hepatocellular carcinoma (HCC) remains elusive. In this study, we found that TRAF4 was highly expressed in HCC cell lines and HCC tissues compared with normal liver cell lines and adjacent noncancerous tissues. TRAF4 overexpression in HCC tissues was correlated with tumor quantity and vascular invasion. In vitro studies showed that TRAF4 was associated with HCC cell migration and invasion. An in vivo study verified that TRAF4 overexpression facilitated metastasis in nude mice. In addition, overexpressed TRAF4 promoted the phosphorylation of Akt and induced Slug overexpression, leading to downregulated E-cadherin and upregulated vimentin, while silencing TRAF4 moderated the phosphorylation of Akt and repressed the expression of Slug, which resulted in upregulated E-cadherin and downregulated vimentin. These effects were inversed after pretreatment of the PI3K/Akt inhibitor LY294002 or overexpression of constitutively active Akt1. Our study demonstrated that TRAF4 was involved in promoting HCC cell migration and invasion. The process was induced by the EMT through activation of the PI3K/Akt signaling pathway.

Expression of CHODL in hepatocellular carcinoma affects invasion and migration of liver cancer cells.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-associated death. Due to rapid progression and metastasis, the long-term survival remains poor for most patients. Thus, it is important to discover and develop novel preventive strategies and therapeutic approaches for HCC. Recent data show that chondrolectin (CHODL) is commonly overexpressed in the majority of lung cancers, indicating a possible correlation between CHODL and metastasis of lung cancer cells. Our investigation shows that the expression of CHODL is significantly decreased in HCC clinical samples and in HCC cell lines. Overexpression of CHODL in SMMC7721 cells with a lentiviral vector increased SMMC7721 cell migration and invasion. Our findings establish for the first time an association between human CHODL and HCC metastasis.

ZKSCAN1 gene and its related circular RNA (circZKSCAN1) both inhibit hepatocellular carcinoma cell growth, migration, and invasion but through different signaling pathways.

There is increasing evidence that circular RNA (circRNA) are involved in cancer development, but the regulation and function of human circRNA remain largely unknown. In this study, we demonstrated that ZKSCAN1, a zinc finger family gene, is expressed in both linear and circular (circZKSCAN1) forms of RNA in human hepatocellular carcinoma (HCC) tissues and cell lines. Here, we analyzed a cohort of 102 patients and found that expression of both ZKSCAN1mRNA and circZKSCAN1 was significantly lower (P < 0.05) in the HCC samples compared with that in matched adjacent nontumorous tissues by reverse transcription PCR (RT-PCR). The low expression level of ZKSCAN1 was only associated with tumor size (P = 0.032), while the cirZKSCAN1 levels varied in patients with different tumor numbers (P < 0.01), cirrhosis (P = 0.031), vascular invasion (P = 0.002), or microscopic vascular invasion (P = 0.002), as well as with the tumor grade (P < 0.001). Silencing both ZKSCAN1mRNA and circZKSCAN1 promoted cell proliferation, migration, and invasion. In contrast, overexpression of both forms of RNA repressed HCC progression in vivo and in vitro. Silencing or overexpression of both forms of RNA did not interfere with each other. RNA-seq revealed a very different molecular basis for the observed effects; ZKSCAN1mRNA mainly regulated cellular metabolism, while circZKSCAN1 mediated several cancer-related signaling pathways, suggesting a nonredundant role for ZKSCAN1mRNA and circRNA. In conclusion, our results revealed two post-translational products (ZKSCAN1mRNA and circZKSCAN1) that cooperated closely with one another to inhibit growth, migration, and invasion of HCC. cirZKSCAN1 might be a useful marker for the diagnosis of HCC.