Design of inductive electrostatic boom spray system based on embedded closed electrode structure and droplet distribution test in soybean field.

The large water demand, insufficient deposition on the back of the leaf and the uneven distribution of droplets are the problems of traditional agricultural ground plant protection machinery, which leads to low agricultural control efficiency. Combined with the advantages of electrostatic spray technology and the characteristics of high working efficiency and low probability of droplets drift of ground sprayer, an inductive electrostatic boom spray system based on embedded electrode structure is designed and mounted on a large self-propelled boom sprayer for field testing. Based on the working characteristics of the fan nozzle and the analysis of the theory of charge, the inductive electrostatic spray device is designed. The performance of the device is tested and the rationality of the system design is verified by COMSOL numerical simulations, charge-to-mass ratio, and particle size distribution measurements. The spray deposition scanning software and the Box-Behnken experimental design method are used to analyze the spray droplet deposition rate and coverage density of the sprayer on the front and back of the target leaves. The results show that the embedded closed electrode structure designed in this paper can avoid the problem of electrode wetting, and the electric field generated by it is mainly concentrated in the spray liquid film area, and the intensity reaches 6~7 V/m. At the conventional application height (500 mm), the maximum charge-to-mass ratio is 2.91 mC/kg, and the average particle size is 168.22 µm, which is 12.87% lower than that of ordinary spray, when the spray pressure is 0.3 MPa and the electrostatic voltage is 12 kV. The results of field experiments show that the optimum combination of the working parameters with the spray speed is 8.40 m/s, the spray pressure is 0.35 MPa, the charging voltage is 11.50 kV, the amount of droplet deposition in the lower dorsal area of the blade is 1.44 µL·cm-2. This study can provide a certain basis for the application of electrostatic spray technology in ground sprayers.

Bone and Extracellular Signal-Related Kinase 5 (ERK5).

Bones are vital for anchoring muscles, tendons, and ligaments, serving as a fundamental element of the human skeletal structure. However, our understanding of bone development mechanisms and the maintenance of bone homeostasis is still limited. Extracellular signal-related kinase 5 (ERK5), a recently identified member of the mitogen-activated protein kinase (MAPK) family, plays a critical role in the pathogenesis and progression of various diseases, especially neoplasms. Recent studies have highlighted ERK5's significant role in both bone development and bone-associated pathologies. This review offers a detailed examination of the latest research on ERK5 in different tissues and diseases, with a particular focus on its implications for bone health. It also examines therapeutic strategies and future research avenues targeting ERK5.

Individual Pig Identification Using Back Surface Point Clouds in 3D Vision.

The individual identification of pigs is the basis for precision livestock farming (PLF), which can provide prerequisites for personalized feeding, disease monitoring, growth condition monitoring and behavior identification. Pig face recognition has the problem that pig face samples are difficult to collect and images are easily affected by the environment and body dirt. Due to this problem, we proposed a method for individual pig identification using three-dimension (3D) point clouds of the pig's back surface. Firstly, a point cloud segmentation model based on the PointNet++ algorithm is established to segment the pig's back point clouds from the complex background and use it as the input for individual recognition. Then, an individual pig recognition model based on the improved PointNet++LGG algorithm was constructed by increasing the adaptive global sampling radius, deepening the network structure and increasing the number of features to extract higher-dimensional features for accurate recognition of different individuals with similar body sizes. In total, 10,574 3D point cloud images of ten pigs were collected to construct the dataset. The experimental results showed that the accuracy of the individual pig identification model based on the PointNet++LGG algorithm reached 95.26%, which was 2.18%, 16.76% and 17.19% higher compared with the PointNet model, PointNet++SSG model and MSG model, respectively. Individual pig identification based on 3D point clouds of the back surface is effective. This approach is easy to integrate with functions such as body condition assessment and behavior recognition, and is conducive to the development of precision livestock farming.

Weed detection in soybean fields using improved YOLOv7 and evaluating herbicide reduction efficacy.

With the increasing environmental awareness and the demand for sustainable agriculture, herbicide reduction has become an important goal. Accurate and efficient weed detection in soybean fields is the key to test the effectiveness of herbicide application, but current technologies and methods still have some problems in terms of accuracy and efficiency, such as relying on manual detection and poor adaptability to some complex environments. Therefore, in this study, weeding experiments in soybean fields with reduced herbicide application, including four levels, were carried out, and an unmanned aerial vehicle (UAV) was utilized to obtain field images. We proposed a weed detection model-YOLOv7-FWeed-based on improved YOLOv7, adopted F-ReLU as the activation function of the convolution module, and added the MaxPool multihead self-attention (M-MHSA) module to enhance the recognition accuracy of weeds. We continuously monitored changes in soybean leaf area and dry matter weight after herbicide reduction as a reflection of soybean growth at optimal herbicide application levels. The results showed that the herbicide application level of electrostatic spraying + 10% reduction could be used for weeding in soybean fields, and YOLOv7-FWeed was higher than YOLOv7 and YOLOv7-enhanced in all the evaluation indexes. The precision of the model was 0.9496, the recall was 0.9125, the F1 was 0.9307, and the mAP was 0.9662. The results of continuous monitoring of soybean leaf area and dry matter weight showed that herbicide reduction could effectively control weed growth and would not hinder soybean growth. This study can provide a more accurate, efficient, and intelligent solution for weed detection in soybean fields, thus promoting herbicide reduction and providing guidance for exploring efficient herbicide application techniques.

Biomechanical effects of different lateral mass injury patterns on subaxial cervical fracture dislocations after anterior cervical surgery: a finite element study.

OBJECTIVE: The lateral mass joint plays an important role in maintaining the mechanical stability of the subaxial cervical spine. We first performed a three-dimensional finite element (FE) biomechanical study to evaluate the local mechanical stability of subaxial cervical fracture dislocations after anterior-only fixation for lateral mass injuries of varying severity. METHODS: A three-dimensional FE model of the subaxial cervical spine with simple anterior fixation for C5-6 fracture dislocation was reconstructed. According to their different morphological characteristics of unilateral lateral mass injuries, the lateral mass injury was divided into six types. The range of motion (ROM) of each part and the stress of the cage, each intervertebral disc, titanium plate, and screw stress were recorded. RESULTS: The ROM of C3-4, C4-5, C5-6, and C6-7 in type 4 was higher than that of the other five types. The maximum equivalent stress on C4-5 intervertebral discs, titanium plates, and screws in type 4 under various sports loads was higher than that produced by the other load types. In the stress cloud diagram of the front titanium plate and screws, the degree of stress was the highest in type 4. Stress placed on each part of the model, from high to low, was as follows: plate, screw, C6, C5, and C7. CONCLUSION: Greater injury severity is associated with higher stress on the plate and screw with exercise loads. Type 4 lateral mass injuries, characterized by ipsilateral pedicle and lamina junction fractures, significantly affected biomechanical stability after simple anterior fixation.

Risk factors for proximal junctional kyphosis after posterior long-segment internal fixation for chronic symptomatic osteoporotic thoracolumbar fractures with kyphosis.

BACKGROUND: This study aimed to analyze the risk factors for proximal junctional kyphosis (PJK) for patients with chronic symptomatic osteoporotic thoracolumbar fractures (CSOTLF) and kyphosis who underwent long-segment internal fixation. METHODS: We retrospectively reviewed the records of patients with CSOTLF complicated with kyphosis who underwent posterior multilevel internal fixation in our hospital between January 2013 and January 2020. The patients' age, sex, body mass index (BMI), bone mineral density (BMD), smoking status, cause of injury, comorbidities, injury segments, and American Spinal Injury Association (ASIA) grading non-surgical data; posterior ligament complex (PLC) injury, upper and lower instrumented vertebral position (UIV and LIV, respectively), number of fixed segments surgical data, proximal junctional angle (PJA), sagittal vertebral axis (SVA), pelvic incidence (PI), lumbar lordosis (LL), pelvic incidence-lumbar lordosis mismatch (PI-LL), pelvic tilt (PT), and sacral slope (SS) surgical indicators were collected. Patients were divided into postoperative PJK and non-PJK groups. RESULTS: This study included 90 patients; among them, 30 (31.58%) developed PJK postoperatively. All patients were followed up for > 24 months (mean 32.5 months). Univariate analysis showed significant differences in age, BMI, BMD, PLC injury, UIV, and LIV fixation position, number of fixation stages, and preoperative PJA, SVA, PI-LL, and SS between the two groups (P < 0.05). Additionally, no significant differences were observed in sex, smoking, cause of injury, complications, injury segment ASIA grade, and preoperative PT between the two groups (P > 0.05). Multifactorial logistic regression analysis showed that age > 70 years (OR = 32.279, P < 0.05), BMI > 28 kg/m2 (OR = 7.876, P < 0.05), BMD T value < - 3.5 SD (OR = 20.836, P < 0.05), PLC injury (OR = 13.981, P < 0.05), and preoperative PI-LL > 20° (OR = 13.301, P < 0.05) were risk factors for PJK after posterior long-segment internal fixation in elderly patients with CSOTLF complicated with kyphosis. CONCLUSION: CSOTLF patients undergoing posterior long segment internal fixation are prone to PJK, and age > 70 years, BMI > 28 kg/m2, BMD T value < - 3.5 SD, preoperative PI-LL > 20° and PLC injury may increase their risk.

Can paraspinal muscle degeneration be a reason for refractures after percutaneous kyphoplasty? A magnetic resonance imaging observation.

BACKGROUND: Vertebral augmentation (VA) techniques are used to treat acute osteoporotic vertebral compression fractures (OVCFs). However, the incidence of recurrent vertebral fractures after VA is controversial. Various factors have been discussed in the literature, but no convincing study on the quality of paraspinal muscles has been reported. The purposes of this study were to evaluate the changes in paraspinal muscles and discuss the relationship between paraspinal muscle degeneration and vertebral refractures after percutaneous kyphoplasty (PKP). METHODS: This retrospective study was conducted in patients who underwent PKP for an initial OVCF between July 2017 and August 2018. Patients were followed up and categorized in the refractured or non-refractured group. A final magnetic resonance imaging (MRI) scan and a preoperative MRI scan were used to determine the measurements. The paraspinal muscles at the mid-height level of the initial fractured vertebral body were measured using regions of interest (ROIs), including the cross-sectional area (CSA) and signal intensity (SI). The changes in the observed data were compared between the groups using rank-sum tests. RESULTS: Overall, 92 patients were enrolled in the study; 33 of them sustained vertebral refractures during the follow-up and the other 59 patients did not. There were no significant differences in terms of sex, age, preoperative bone mineral density, and body mass index between the groups (all, P > 0.05). The refractured group had a significantly higher decrease in the ROI-CSA and CSA/SI, and a higher increase in ROI-SI, compared with the preoperative data (all, P < 0.05). CONCLUSIONS: The quality of paraspinal muscles significantly decreased in patients with new OVCFs after PKP. This brings a new perspective to the study of postoperative recurrent fractures; patients and physicians need to pay more attention to the efficacy of bed rest and bracing.

Can Additional Facet Joint Block Improve the Clinical Outcome of Kyphoplasty for Acute Osteoporotic Vertebral Compression Fractures?

BACKGROUND: Percutaneous kyphoplasty (PKP) has been reported to provide a favorable analgesic effect for pain caused by osteoporotic vertebral compression fractures (OVCFs). However, a systematic review demonstrated that pain relief was only reported for approximately 86% of kyphoplasty treatments. OBJECTIVES: To explore whether an additional facet joint block (FJB) can minimize pain and improve the clinical outcome of PKP in patients with acute OVCFs. STUDY DESIGN: Prospective study. SETTING: All data were from Honghui Hospital in Xi'an. METHODS: According to the inclusion and exclusion criteria, 194 patients were eventually included in our study; they were randomly divided into 2 groups of 97 patients each and treated with either PKP + FJB or PKP alone. Follow-up consultations were scheduled 1 day, 3 days, 1 week, 1 month, 3 months, and 1 year postoperatively; the demographic characteristics, related surgical information, and complications observed within both groups were recorded. The clinical evaluation parameters included the intraoperative satisfaction score, the Visual Analog Scale (VAS) score, and the Oswestry Disability Index (ODI). RESULTS: A total of 171 patients (61 men and 110 women; age range: 62-85 years) completed the full postoperative follow-up schedule, with 83 patients in the PKP + FJB group and 88 in the PKP group. No significant differences were observed in the genders, ages, preoperative bone mineral density, surgical levels, or volume of cement injected between the 2 groups (P > 0.05, respectively). The average duration of the surgeries in the PKP + FJB group was slightly longer than that in the PKP group (35.5 ± 4.8 min vs. 31.8 ± 4.3 min; P = 0.038), and in terms of the clinical outcomes, the average intraoperative satisfaction score was significantly higher in the PKP + FJB group (8.6 ± 1.1 vs. 6.3 ± 1.3; P < 0.001). Compared with the preoperative data, significant improvements in the VAS scores of back pain and ODI were observed at each follow-up interval (P < 0.05, respectively). These scores were significantly higher in the PKP + FJB group than in the PKP group; however, this was only observed within the first month after the procedure. LIMITATIONS: A single-center noncontrol study. CONCLUSIONS: The addition of an FJB (which in our study involved a unique combination of ropivacaine, prednisolone, and vitamin B12) improved the short-term clinical outcome of PKP for acute OVCFs. The local anti-inflammatory and analgesic effects on the facet joints resulted in higher intraoperative satisfaction and lower VAS and ODI scores for the first postoperative month when compared with the PKP group.

When is the circumferential stabilization necessary for subaxial cervical fracture dislocations? The posterior ligament-bone injury classification and severity score: a novel treatment algorithm.

OBJECTIVE: To propose a novel classification and scoring system called the posterior ligament-bone injury classification and severity score (PLICS) that offers a quantitative score to guide the need for posterior stabilization in addition to anterior reconstruction for subaxial cervical fracture dislocations (SCFDs). METHODS: A total of 456 patients with SCFDs were prospectively included. Patients with PLICS ≥ 7 together with extremely unstable lateral mass fracture (EULMF) were classified as high-risk group, and the other patients were classified as low-risk group. For patients in the low-risk group, anterior-only reconstruction was performed; for patients in the high-risk group, additional posterior lateral mass fixation and fusion was performed after anterior reconstruction. Clinical outcome evaluation included using the visual analogue score (VAS), the Neck Disability Index (NDI), and the American Spinal Injury Association (ASIA) impairment scale. The change in the local sagittal alignment kyphosis Cobb angle was also recorded. RESULTS: A total of 370 patients (81.1%) completed the minimal 12-month follow-ups, including 321 patients of low-risk group and 49 patients of high-risk group. Compared with the average VAS score preoperatively, the score at 12-month follow-up was significantly improved (from 6.1 + 0.3 to 1.1 + 0.2 in the low-risk group, P < 0.001; from 6.4 + 0.2 to 1.4 + 0.2 in the high-risk group, P < 0.001). The average NDI score at the 12-month follow-up was statistically low in the low-risk group (8.8 + 2.5 vs 13.8 + 3.4, P = 0.034). At least more than one grade improvement in the ASIA scale was observed in 80.5% of all patients. The local kyphosis Cobb angle at the injured segment averaged improved in both groups. CONCLUSION: A PLICS score ≥ 7 together with EULMF can be the threshold for posterior stabilization in addition to anterior reconstruction for the patients with SCFDs.

[Polymethylmethacrylate-augmented screw fixation in treatment of senile thoracolumbar tuberculosis combined with severe osteoporosis].

OBJECTIVE: To explore the safety and effectiveness of polymethylmethacrylate-augmented screw fixation (PASF) in the treatment of elderly thoracolumbar tuberculosis combined with severe osteoporosis. METHODS: The clinical data of 20 elderly patients with thoracolumbar tuberculosis and severe osteoporosis who underwent PASF after anterior or posterior debridement and bone grafting and met the selection criteria between December 2012 and December 2014 were retrospectively analyzed. There were 8 males and 12 females with an average age of 68.5 years (range, 65-72 years). T value of bone mineral density was -4.2 to -3.6, with an average of -3.9. There were 12 cases of thoracic tuberculosis, 3 cases of thoracolumbar tuberculosis, and 5 cases of lumbar tuberculosis. The diseased segments involved T 3-L 4, including 11 cases of single-segment disease, 6 cases of double-segment disease, and 3 cases of multi-segment disease. The disease duration was 3-9 months, with an average of 6 months. The preoperative spinal nerve function of the patients was evaluated by the American Spinal Injury Association (ASIA) grading. There were 2 cases of grade A, 5 cases of grade B, 6 cases of grade C, 4 cases of grade D, and 3 cases of grade E. Postoperative imaging examination was used to evaluate the bone graft fusion and paravertebral abscess absorption, and to measure the Cobb angle of the segment to evaluate the improvement of kyphosis. The levels of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were tested. The visual analogue scale (VAS) score, Oswestry disability index (ODI), and ASIA grading were used to evaluate the effectivreness before operation, at 1 month after operation, and at last follow-up. The clinical cure of tuberculosis was also evaluated. RESULTS: All operation successfully completed. The operation time was 154-250 minutes, with an average of 202 minutes; the intraoperative blood loss was 368-656 mL, with an average of 512 mL. All 20 patients were followed up 18-42 months, with an average of 26.8 months. The postoperative pain and symptoms of tuberculosis in all patients relieved, and the paravertebral abscess was absorbed, reaching the cure standard for spinal tuberculosis. All bone grafts fusion achieved within 1 year after operation. Only 1 case had asymptomatic bone cement leakage into the paravertebral veins, and the remaining patients had no serious complications such as bone cement leakage in the spinal canal, pulmonary embolism, and neurovascular injury. At last follow-up, spinal cord nerve function significantly improved when compared with preoperative one. Among them, ASIA grading were 7 cases of grade C, 8 cases of grade D, and 5 cases of grade E, showing significant difference when compared with preoperative one ( Z=2.139, P=0.000). VAS score, ODI score, segmental Cobb angle, ESR, and CRP at 1 month after operation and at last follow-up were significantly improved when compared with preoperative ones ( P<0.05); there was no significant difference between 1 month after operation and last follow-up ( P>0.05). During the follow-up, no complications such as failure of internal fixation, proximal junctional kyphosis, or tuberculosis recurrence occurred. CONCLUSION: For elderly patients with thoracolumbar tuberculosis and severe osteoporosis, PASF treatment is safe and effective.

Comparison of Clinical and Radiologic Outcome Between Mini-Open Wiltse Approach and Fluoroscopic-Guided Percutaneous Pedicle Screw Placement: A Randomized Controlled Trial.

OBJECTIVE: To compare clinical efficacy, radiographic outcome, and radiation exposure between mini-open pedicle screw (MPS) fixation with the Wiltse approach and percutaneous pedicle screw (PPS) fixation in treatment of young and middle-aged patients with thoracolumbar burst fractures. METHODS: Of 60 patients with thoracolumbar vertebrae fractures treated in our hospital from January 2017 to January 2018, 30 were randomly assigned to the MPS group and 30 were randomly assigned to the PPS group. Clinical efficacy, radiographic outcome, and radiation exposure were compared between the 2 groups. RESULTS: The average age of patients was 42.2 ± 6.7 years in the MPS group and 43.0 ± 6.9 years in the PPS group (P = 0.668). There was no significant difference between the 2 groups in blood loss, hospital stay, postoperative visual analog scale score for back pain, and Oswestry Disability Index score. The vertebral body height and vertebral body angle of the MPS group were significantly better than those of the PPS group at the last follow-up. There was no significant difference in the accuracy rate of pedicle screw placement between the MPS group and the PPS group; the facet joint violation was significantly higher in the PPS group. The average radiation exposure dosage was lower in the MPS group. CONCLUSIONS: Both MPS fixation with the Wiltse approach and PPS fixation are safe and effective in the treatment of single-segment thoracolumbar vertebral fractures. Nevertheless, considering the surgical duration, radiation exposure, facet joint violation, vertebral body height, and vertebral body angle at the last follow-up, MPS fixation with the Wiltse approach is a better choice than PPS.

The novel lncRNA p4516 acts as a prognostic biomarker promoting gastric cancer cell proliferation and metastasis.

Purpose: Emerging evidence has shown that long noncoding RNAs (lncRNAs) participate in oncogenesis and tumor progression. We previously found a novel lncRNA p4516 which was closely associated with prognosis by preliminary study of lncRNA expression profile from paired tumors and nontumor tissues in 198 gastric cancer (GC) patients. However, the exact biological functions and the underlying molecular mechanisms of p4516 in gastric tumorigenesis still remain unclear. Materials and methods: The RNA fluorescence in situ hybridization (RNA-FISH) analysis, cytoplasmic and nuclear RNA isolation and qRT-PCR were applied to determine the subcellular localization of p4516. Expression levels of p4516 were assessed using qRT-PCR in both GC cell lines and in 142 primary GC tissues. Correlations between p4516 expression and GC patients' clinicopathological parameters were analyzed. Gain- and loss-of-function experiments were employed to investigate the role of p4516 in proliferation, migration and invasion both in vitro and in vivo. In addition, Western blotting and immunohistochemical staining were used to examine the protein expression levels. Results: LncRNA p4516 was mainly localized in the nucleus of GC cells and p4516 tended to have higher expression levels in GC cells compared to the normal gastric mucosa-derived cells GES-1. Furthermore, higher expression levels of p4516 correlated with worse clinical outcomes in GC patients and acted as an independent prognostic biomarker. Functional analysis revealed that p4516 participated in the regulation of GC cell proliferation, invasion and migration both in vivo and in vitro. Moreover, p4516 was involved in epithelial-mesenchymal transition (EMT) in GC cells. Conclusion: Our study demonstrated the oncogenic role of novel lncRNA p4516 in the gastric carcinogenesis for the first time. High expression of p4516 may act as prognostic marker in patient with gastric cancer.

ISL1 predicts poor outcomes for patients with gastric cancer and drives tumor progression through binding to the ZEB1 promoter together with SETD7.

ISL1, a LIM-homeodomain transcription factor, serves as a biomarker of metastasis in multiple tumors. However, the function and underlying mechanisms of ISL1 in gastric cancer (GC) have not been fully elucidated. Here we found that ISL1 was frequently overexpressed in GC FFPE samples (104/196, 53.06%), and associated with worse clinical outcomes. Furthermore, the overexpression of ISL1 and loss-of-function of ISL1 influenced cell proliferation, invasion and migration in vitro and in vivo, including GC patient-derived xenograft models. We used ChIP-seq and RNA-seq to identify that ISL1 influenced the regulation of H3K4 methylation and bound to ZEB1, a key regulator of the epithelial-mesenchymal transition (EMT). Meanwhile, we validated ISL1 as activating ZEB1 promoter through influencing H3K4me3. We confirmed that a complex between ISL1 and SETD7 (a histone H3K4-specific methyltransferase) can directly bind to the ZEB1 promoter to activate its expression in GC cells by immunoprecipitation, mass spectrometry, and ChIP-re-ChIP. Moreover, ZEB1 expression was significantly positively correlated with ISL1 and was positively associated with a worse outcome in primary GC specimens. Our paper uncovers a molecular mechanism of ISL1 promoting metastasis of GC through binding to the ZEB1 promoter together with co-factor SETD7. ISL1 might be a potential prognostic biomarker of GC.

Formation of Different Si3N4 Nanostructures by Salt-Assisted Nitridation.

Silicon nitride (Si3N4) products with different nanostructure morphologies and different phases for Si3N4 ceramic with high thermal conductivity were synthesized by a direct nitriding method. NaCl and NH4Cl were added to raw Si powders, and the reaction was carried out under a nitrogen gas flow of 100 mL/min. The phase composition and morphologies of the products were systemically characterized by X-ray diffraction, field emission scanning electron microscopy, and high-resolution transmission electron microscopy. At 1450 °C, the NaCl content was 30 wt %, the NH4Cl content was 3 wt %, and the maximum α-Si3N4 content was 96 wt %. The process of Si nitridation can be divided into three stages by analyzing the reaction schemes: in the first stage (25-900 °C), NH4Cl decomposition and the generation of stacked amorphous Si3N4 occurs; in the second stage (900-1450 °C), NaCl melts and Si3N4 generates; and in the third stage (>1450 °C), α-Si3N4 → ß-Si3N4 phase change and the evaporation of NaCl occurs. The products are made of two layers: a thin upper layer of nanowires containing different nanostructures and a lower layer mainly comprising fluffy, blocky, and short needlelike products. The introduction of NaCl and NH4Cl facilitated the evaporation of Si powders and the decomposition of Al2O3 from porcelain boat and furnace tube, which resulted in the mixing of N2, O2, Al2O, and Si vapors and generated Al xSi yO z nanowires with rough surfaces and lead to thin Si3N4 nanowires, nanobranches by the vapor-solid (VS), vapor-liquid-solid (VLS), and the double-stage VLS base and VS tip growth mechanisms.

Analysis of PD1, PDL1, PDL2 expression and T cells infiltration in 1014 gastric cancer patients.

Although immune checkpoint blockade have demonstrated promising results, their effects on gastric cancer (GC) are under investigation. Understanding the clinical significance of PD1 and its ligands' expression, together with T cell infiltration might provide clues for biomarkers screening in GC immunotherapy. Immunohistochemistry were performed on a tissue microarray including 1,014 GC specimens using PD1, PDL1 and PDL2 antibodies. T cell markers CD3 and CD8 were also stained and quantified by automated image analysis. Correlation with clinical features and outcome were analyzed after controlling for potential confounders including EBV infection, HER2, C-met and PCNA expression. 37.8% of the cases showed membranous PD-L1 expression in tumor cells and 74.9% in infiltrating immune cells. PDL1 expression rate was rather higher in patients without metastasis, in EBV positive group and those with C-met and PCNA expression. GC patients with high level PDL1 expression exhibited better survival. GC Patients with higher T cell infiltration also showed elevated PDL1, PDL2 and PD1 expression and predict favorable outcome, indicating an adaptive immune resistance mechanism may exist. The group of patients infiltrated with lower density CD3+ T cells also without PDL1 expression in tumor cells predict the worst outcome in the subgroup of different PTNM stage, which may suggest an inactive immune status. These results highlights the need to assess both PDL1 expression in all tumor context and the characterization of the GC immune microenvironment.

High-level SAE2 promotes malignant phenotype and predicts outcome in gastric cancer.

BACKGROUND: The SUMO pathway has been shown to play an important role in tumorigenesis. This report analyzed the involvement of the sole SUMO-Activating Enzyme Subunit 2 (SAE2) in human gastric cancer (GC) progression and prognosis. METHODS: Expression of SAE2 was examined by Quantigene Plex, western blotting and immunohistochemistry. The expression of SAE2 and c-MYC were detected in parallel in 276 cases. The molecular mechanisms of SAE2 expression and its effects on cell growth, colony formation, migration and invasion were also explored by CCK8 assay, colony formation experiment, transwell chamber assay with or without matrigel, immunoprecipitation and in vivo tumorigenesis and tumor metastasis. RESULTS: SAE2 was markedly overexpressed in GC cell lines and primary tumor samples of GC, and significantly correlated with deeper tumor depth, distant metastasis, higher pathological stage and stratified survival in human GC. SAE2 positivity was independently associated with a worse outcome in multivariate analysis. Knockdown of SAE2 expression inhibited the proliferation, migration, and invasion of SAE2-overexpressing GC cells. Consistent with the in vitro results, down-regulation of SAE2 in human GC BGC823 cells significantly reduced the tumorigenic and metastatic potential of the cells in vivo. SAE2 protein was significantly associated with the higher expression of c-MYC in primary GC tissues. Moreover, FoxM1 was SUMOylated in GC and that inhibition of SAE2 resulted in a decrease in SUMO1-FoxM1 levels compared with those in the controls. CONCLUSIONS: These findings suggest that SAE2 has a pivotal role in the aggressiveness of GC, and highlight its usefulness as a prognostic factor in GC.

High-level SAE2 promotes malignant phenotype and predicts outcome in gastric cancer.

BACKGROUND: The SUMO pathway has been shown to play an important role in tumorigenesis. This report analyzed the involvement of the sole SUMO-Activating Enzyme Subunit 2 (SAE2) in human gastric cancer (GC) progression and prognosis. METHODS: Expression of SAE2 was examined by Quantigene Plex, western blotting and immunohistochemistry. The expression of SAE2 and c-MYC were detected in parallel in 276 cases. The molecular mechanisms of SAE2 expression and its effects on cell growth, colony formation, migration and invasion were also explored by CCK8 assay, colony formation experiment, transwell chamber assay with or without matrigel, immunoprecipitation and in vivo tumorigenesis and tumor metastasis. RESULTS: SAE2 was markedly overexpressed in GC cell lines and primary tumor samples of GC, and significantly correlated with deeper tumor depth, distant metastasis, higher pathological stage and stratified survival in human GC. SAE2 positivity was independently associated with a worse outcome in multivariate analysis. Knockdown of SAE2 expression inhibited the proliferation, migration, and invasion of SAE2-overexpressing GC cells. Consistent with the in vitro results, down-regulation of SAE2 in human GC BGC823 cells significantly reduced the tumorigenic and metastatic potential of the cells in vivo. SAE2 protein was significantly associated with the higher expression of c-MYC in primary GC tissues. Moreover, FoxM1 was SUMOylated in GC and that inhibition of SAE2 resulted in a decrease in SUMO1-FoxM1 levels compared with those in the controls. CONCLUSIONS: These findings suggest that SAE2 has a pivotal role in the aggressiveness of GC, and highlight its usefulness as a prognostic factor in GC.