A quick and reliable image-based AI algorithm for evaluating cellular senescence of gastric organoids

Objective:Organoids are a powerful tool with broad application prospects in biomedicine.Notably,they provide alternatives to animal models for testing potential drugs before clinical trials.However,the number of passages for which organoids maintain cellular vitality ex vivo remains unclear.Methods:Herein,we constructed 55 gastric organoids from 35 individuals,serially passaged the organoids,and captured microscopic images for phenotypic evaluation.Senescence-associatedβ-galactosidase(SA-β-Gal),cell diameter in suspension,and gene expression reflecting cell cycle regulation were examined.The YOLOv3 object detection algorithm integrated with a convolutional block attention module(CBAM)was used to evaluate organoid vitality.Results:SA-β-Gal staining intensity;single-cell diameter;and expression of p15,p16,p21,CCNA2,CCNE2,and LMNB1 reflected the progression of aging in organoids during passaging.The CBAM-YOLOv3 algorithm precisely evaluated aging organoids on the basis of organoid average diameter,organoid number,and number×diameter,and the findings positively correlated with SA-β-Gal staining and single-cell diameter.Organoids derived from normal gastric mucosa had limited passaging ability(passages 1–5),before aging,whereas tumor organoids showed unlimited passaging potential for more than 45 passages(511 days)without showing clear senescence.Conclusions:Given the lack of indicators for evaluating organoid growth status,we established a reliable approach for integrated analysis of phenotypic parameters that uses an artificial intelligence algorithm to indicate organoid vitality.This method enables precise evaluation of organoid status in biomedical studies and monitoring of living biobanks.

Benchmark for establishment of organoids from gastrointestinal epithelium and cancer based on available consumables and reagents

Gastrointestinal cancers are a public health problem that threatens the lives of human being. A good experimental model is a powerful tool to promote the uncovering pathogenesis and establish novel treatment methods. High-quality biomedical research requires experimental models to recapitulate the physiological and pathological states of their parental tissues as much as possible. Organoids are such experimental models. Organoids refer to small organlike cellular clusters formed by the expansion and passaging of living tissues in 3D culture medium in vitro.Organoids are highly similar to the original tissues in terms of cellular composition, cell functions, and genomic profiling. Organoids have many advantages, such as short preparation cycles, long-term storage based on cryopreservation, and reusability. In recent years, researchers carried out the establishment of organoids from gastrointestinal mucosa and cancer tissues, and accumulated valuable experiences. In order to promote effective usage and further development of organoid-related technologies in the research of gastrointestinal diseases, this study proposes a benchmark based on utilization of available experimental consumables and reagents, which are involved in the key steps such as collection and pretreatment of biospecimen, organoid construction, organoid cryopreservation and recovery, growth status evaluation, and organoid quality control. We believe that the standard for the construction and preservation of organoids derived from human gastrointestinal epithelium and cancer tissues can provide an important reference for the majority of scientific researchers.

Artificial intelligence efficiently predicts gastric lesions,Helicobacter pylori infection and lymph node metastasis upon endoscopic images

Objective:Medical images have been increased rapidly in digital medicine era,presenting an opportunity for the intervention of artificial intelligence(AI).In order to explore the value of convolutional neural network(CNN)algorithms in endoscopic images,we developed an AI-assisted comprehensive analysis system for endoscopic images and explored its performance in clinical real scenarios.Methods:A total of 6,270 white light endoscopic images from 516 cases were used to train 14 different CNN models.The images were divided into training set,validation set and test set according to 7:1:2 for exploring the possibility of discrimination of gastric cancer(GC)and benign lesions(nGC),gastric ulcer(GU)and ulcerated cancer(UCa),early gastric cancer(EGC)and nGC,infection of Helicobacter pylori(Hp)and no infection of Hp(noHp),as well as metastasis and no-metastasis at perigastric lymph nodes.Results:Among the 14 CNN models,EfficientNetB7 revealed the best performance on two-category of GC and nGC[accuracy:96.40%and area under the curve(AUC)=0.9959],GU and UCa(accuracy:90.84%and AUC=0.8155),EGC and nGC(accuracy:97.88%and AUC=0.9943),and Hp and noHp(accuracy:83.33%and AUC=0.9096).Whereas,InceptionV3 model showed better performance on predicting metastasis and nometastasis of perigastric lymph nodes for EGC(accuracy:79.44%and AUC=0.7181).In addition,the integrated analysis of endoscopic images and gross images of gastrectomy specimens was performed on 95 cases by EfficientNetB7 and RFB-SSD object detection model,resulting in 100%of predictive accuracy in EGC.Conclusions:Taken together,this study integrated image sources from endoscopic examination and gastrectomy of gastric tumors and incorporated the advantages of different CNN models.The AI-assisted diagnostic system will play an important role in the therapeutic decision-making of EGC.

New blood markers detection technology:A leap in thediagnosis of gastric cancer

Gastric cancer(GC) is still one of the malignant tumors with high morbidity and mortality in the world, with a 5-year survival rate of less than 30%. GC is often either asymptomatic or causes only nonspecific symptoms in its early stages, whereas when the symptoms manifest, the cancer has usually reached an advanced stage, which is one of the main causes of its relatively poor prognosis. Hence, the main focus of GC research has been on discovering new tools and technology to predict, screen and diagnose g C at an early stage which would prompt early treatment. With the tremendous advances in the OMICS technology, serum proteomics has been in the limelight of cancer research over the last few decades and has steered the development of several methods helping to understand the mechanisms underlying gastric carcinogenesis, resulting in the identification of a large number of molecular targets such as circulating tumor cells(CTCs), cell free DNA(cf DNA) and cell tumor DNA(ct DNA) and their sub-molecular components such as mi RNA, that show great promise as GC biomarkers. In this review, we are underlying the recent breakthroughs about new blood markers technology for GC while scrutinizing the potential clinical use of CTCs, cf DNA, ct DNA and the role of the methylation of their submolecular components in the pathogenesis, diagnosis and management of GC.

Reoperation for early postoperative complications after gastric cancer surgery in a Chinese hospital

AIM:To investigate the occurrence of postoperative complications of gastric cancer surgery,and analyze the potential causes of reoperation for early postoperative complications. METHODS:A total of 1639 patients who underwent radical or palliative gastrectomies for gastric cancer were included in the study.The study endpoint was the analysis of postoperative complications in inpatients. RESULTS:About 31%of patients had early postoperative complications,and complications of infection occurred most frequently.Intra-abdominal hemorrhage and anastomotic leak were the main causes of reoperation,which accounted for about 2.2%.Mortality was 11.1%in the reoperation group,but was only 0.8%in other patients.The duration of postoperative stay in hospital was significantly longer and the total expenditure was markedly higher in the patients who underwent reoperation(P<0.001).There was no significant association of any available factors in this study with the high rate of reoperation.CONCLUSION:Reoperation significantly increases the mortality rate and raises the burden of the surgical unit.More prospective studies are required to explore the potential risk factors.

Higher CO_2-insufflation pressure inhibits the expression of adhesion molecules and the invasion potential of colon cancer cells

AIM： To investigate the influence of CO2-insufflation pressure on adhesion, invasion and metastatic potential of colon cancer cells based on adhesion molecules expression. METHODS： With an/n vitro artificial pneumoperitoneum model, SW1116 human colon carcinoma cells were exposed to CO2-insufflation in 5 different pressure groups： 6 mmHg, 9 mmHg, 12 mmHg, 15 mmHg and control group, respectively for 1 h. Expression of E-cadherin, ICAM-I, CD44 and E-selectin was meas- ured at 0, 12, 24, 48 and 72 h after CO2-insufflation using flow cytometry. The adhesion and invasion capacity of SW1116 cells before and after exposure to CO2-insufflation was detected by cell adhesion/invasion assay in vitro. Each group of cells was injected intraperitoneally into 16 BALB/C mice. The number of visible abdominal cavity tumor nodules, visceral metas-tases and survival of the mice were recorded in each group. RESULTS： The expression of E-cadherin, ICAM-1, CD44 and E-selectin in SWl116 cells were changed significantly following exposure to CO2 insufflation at different pressures （P 〈 0.05）. The expression of E-cadherin, CD44 and ICAM-1 decreased with increasing CO2-insufflation pressure. The adhesive/ invasive cells also decreased gradually with increasing pressure as determined by the adhesion/invasion assay. In animal experiments, the number of abdominal cavity tumor nodules in the 15 mmHg group was also significantly lower than that in the 6 mmHg group （29.7± 9.91 vs 41.7±14.90, P = 0.046）. However, the survival in each group was not statistically different. CONCLUSION： CO2-insufflation induced a temporary change in the adhesion and invasion capacity of cancer cells in vitro. Higher CO2-insufflation pressure inhibited adhesion, invasion and metastatic potential in vitro and in vivo, which was associated with reduced expression of adhesion molecules.

Tumor heterogeneity of gastric cancer: From the perspective of tumor-initiating cell

Gastric cancer(GC) remains one of the most common and malignant types of cancer due to its rapid progression, distant metastasis, and resistance to conventional chemotherapy, although efforts have been made to understand the underlying mechanism of this resistance and to improve clinical outcome. It is well recognized that tumor heterogeneity, a fundamental feature of malignancy, plays an essential role in the cancer development and chemoresistance. The model of tumor-initiating cell(TIC) has been proposed to explain the genetic, histological, and phenotypical heterogeneity of GC. TIC accounts for a minor subpopulation of tumor cells with key characteristics including high tumorigenicity, maintenance of self-renewal potential, giving rise to both tumorigenic and non-tumorigenic cancer cells, and resistance to chemotherapy. Regarding tumor-initiating cell of GC(GATIC), substantial studies have been performed to(1) identify the putative specific cell markers for purification and functional validation of GATICs;(2) trace the origin of GATICs; and(3) decode the regulatory mechanism of GATICs. Furthermore, recent studies demonstrate the plasticity of GATIC and the interaction between GATIC and its surrounding factors(TIC niche or tumor microenvironment). All these investigations pave the way for the development of GATIC-targeted therapy, which is in the phase of preclinical studies and clinical trials. Here, we interpret the heterogeneity of GC from the perspectives of TIC by reviewing the above-mentioned fundamental and clinical studies of GATICs. Problems encountered during the GATIC investigations and the potential solutions are also discussed.

A study on arsenic trioxide inducing in vitro apoptosis of gastric cancer cell lines

INTRODUCTION Cell apoptosis,which involves the biologic regulation of the numbers and vital activity of cells,is an important metaboloc process in both normal cells and tumor cells.

Complications and risk factors for complications of implanted subcutaneous ports for intraperitoneal chemotherapy in gastric cancer with peritoneal metastasis

Objective:Intraperitoneal(IP)chemotherapy through subcutaneous port is an effective treatment for gastric cancer(GC)patients with peritoneal metastasis(PM).The objective of this study is to assess the port complications and risk factors for complications in GC patients with PM.Methods:In retrospective screening of 301 patients with subcutaneous ports implantation,249 GC patients with PM who received IP chemotherapy were screened out for analysis.Port complications and risk factors for complications were analyzed.Results:Of the 249 analyzed patients,57(22.9%)experienced port complications.Subcutaneous liquid accumulation(42.1%)and infection(28.1%)were the main complications,and other complications included port rotation(14.1%),wound dehiscence(12.3%),inflow obstruction(1.7%)and subcutaneous metastasis(1.7%).The median interval between port implantation and occurrence of complications was 3.0 months.Eastern Cooperative Oncology Group(ECOG)performance status[odds ratio(OR),1.74;95%confidence interval(95%CI),1.12-2.69],albumin(OR,3.67;95%CI,1.96-6.86),implantation procedure optimization(OR,0.33;95%CI,0.18-0.61)and implantation groups(OR,0.37;95%CI,0.20-0.69)were independent risk factors for port complications(P<0.05).ECOG performance status was the only factor that related to the grades of port complications(P=0.016).Conclusions:Port complications in GC patients who received IP chemotherapy are manageable.ECOG performance status,albumin,implantation procedure and implantation group are independent risk factors for port complications in GC patients with PM.

Expression of γ-synuclein in colorectal cancer tissues and its role on colorectal cancer cell line HCT116

AIM: To investigate the expression pattern of γ-synuclein in colorectal cancer (CRC) tissues, and to study the effects of γ-synuclein on CRC cell line HCT116 biological features in vitro.METHODS: The expression pattern of γ-synuclein was determined in 54 CRC tissues and 30 tumor-matched nonneoplastic adjacent tissues (NNAT) 5 cm away from the tumor via real-time quantitative reverse transcription PCR (RT-PCR) and immunohistochemistry. The relationship between γ-synuclein protein expression and clinicopathological factors of CRC tissues was analyzed. Three small interfering RNA (siRNA) targeting γ-synuclein mRNA plasmids were constructed and transfected into the CRC cell line HCT116. The stable cell lines were selected with G-418 for 28 d, and the biological features of these cells were examined by cell growth curve, soft agar assay, and cell migration and invasion assays in vitro. RESULTS: The expression of γ-synuclein mRNA and protein was much higher in CRC tissue samples than in NNAT samples (P = 0.02, P = 0.036). There was a significant correlation between the γ-synuclein protein expression and clinical stage and lymph node involvement of CRC (P = 0.02, P = 0.033). In functional analysis we found that down-regulation of γ-synuclein expression in HCT116 cells could inhibit the growth, colony formation rate, and migration and invasion ability of HCT116 cells.CONCLUSION: Increased expression of γ-synuclein in CRC tissues and the biological effects of reduced γ-synuclein expression on HCT116 cells suggest that γ-synuclein may play a positive role in the progression of CRC.

Higher body mass index deteriorates postoperative outcomes of pancreaticoduodenectomy

Background:Previous studies presented controversies in impact of body mass index(BMI)on perioper-ative complications in pancreatectomy,and mainly focused on Western population.This study aimed to explore the impact of BMI on perioperative outcomes in Chinese patients undergoing pancreaticoduo-denectomy.Methods:Seven hundred and seven adult patients undergoing open pancreaticoduodenectomy between January 2005 and December 2016 at Ruijin Hospital were studied retrospectively and categorized as obese(BMI≥25 kg/m^2),overweight(BMI≥23 kg/m^2 and<25 kg/m^2),or normal weight(BMI≥18.5 kg/m^2 and<23 kg/m^2).Associations of these BMI groups with perioperative outcomes were evaluated.Results:The overweight and obese groups experienced higher risk of clinically related postoperative pan-creatic fistula(CR-POPF)(7.6%vs.9.9%vs.17.6%,P=0.002)and re-operation(1.1%vs.2.5%vs.5.1%,P=0.017),and longer systemic inflammation response syndrome(SIRS)duration[2(1–9)d vs.2(1–7)d vs.3(1–10)d,P=0.003]and postoperative hospital stay[19(2–84)d vs.19(7–158)d vs.23(8–121)d,P=0.023]than the normal weight group did.The multiple logistic regression models showed obese as an independent risk factor for CR-POPF(P=0.013).The multiple linear regression analysis confirmed BMI as a predictor for prolonged postoperative hospital stay(P=0.005).Conclusions:Higher BMI results in higher morbidity of Chinese patients undergoing open pancreaticoduo-denectomy.Pancreaticoduodenectomy is still a safe surgery procedure for overweight and obese patients,with intensive perioperative management.

Emerging roles of the ribonucleotide reductase M2 in colorectal cancer and ultraviolet-induced DNA damage repair

AIM:To investigate the roles of the ribonucleotide reductase M2 (RRM2) subunit in colorectal cancer (CRC) and ultraviolet (UV)-induced DNA damage repair. METHODS:Immunohistochemical staining of tissue microarray was performed to detect the expression of RRM2. Seven CRC cell lines were cultured and three human colon cancer cell lines, i.e., HCT116, SW480 and SW620, were used. Reverse transcription polymerase chain reaction and Western blotting were performed to determine the mRNA and protein expression levels of RRM2, respectively. Cell proliferation assay, cell cycle analysis were performed. Cell apoptosis was evaluated by double staining with fluorescein isothiocyanate-conjugated Annexin Ⅴ and propidium iodide (PI) usingAnnexin Ⅴ/PI apoptosis kit. The motility and invasion of CRC cells were assessed by the Transwell chamber assay. Cells were irradiated with a 254 nm UV-C lamp to detect the UV sensitivity after RRM2 depletion. RESULTS:Immunohistochemical staining revealed elevated RRM2 levels in CRC tissues. RRM2 overexpression was positively correlated with invasion depth (P < 0.05), poorly differentiated type (P = 0.0051), and tumor node metastasis stage (P = 0.0015). The expression of RRM2 in HCT116 cells was downregulated after transfection, and HCT116 cell proliferation was obviously suppressed compared to control groups (P < 0.05). In the invasion test, the number of cells that passed through the chambers in the RRM2-siRNA group was 81 ± 3, which was lower than that in the negative control (289 ± 7) and blank control groups (301 ± 7.2). These differences were statistically significant (P < 0.01). Our data suggest that RRM2 overexpression may be associated with CRC progression. RRM2 silencing by siRNA may inhibit the hyperplasia and invasiveness of CRC cells, suggesting that RRM2 may play an important role in the infiltration and metastasis of CRC, which is a potential therapeutic strategy in CRC. In addition, RRM2 depletion increased UV sensitivity. CONCLUSION:These findings suggest that RRM2 may be a facilitating factor in colorectal tumorigenesis and UV-induced DNA damage repair.

Microencapsulated tumor assay:Evaluation of the nude mouse model of pancreatic cancer

AIM: To establish a more stable and accurate nude mouse model of pancreatic cancer using cancer cell microencapsulation. METHODS: The assay is based on microencapsulation technology, wherein human tumor cells are encapsulated in small microcapsules (approximately 420 μm in diameter) constructed of semipermeable membranes. We implemented two kinds of subcutaneous implantation models in nude mice using the injection of single tumor cells and encapsulated pancreatic tumor cells. The size of subcutaneously implanted tumors was observed ona weekly basis using two methods, and growth curves were generated from these data. The growth and metastasis of orthotopically injected single tumor cells and encapsulated pancreatic tumor cells were evaluated at four and eight weeks postimplantation by positron emission tomography-computed tomography scan and necropsy. The pancreatic tumor samples obtained from each method were then sent for pathological examination. We evaluated differences in the rates of tumor incidence and the presence of metastasis and variations in tumor volume and tumor weight in the cancer microcapsules vs single-cell suspensions. RESULTS: Sequential in vitro observations of the microcapsules showed that the cancer cells in microcapsules proliferated well and formed spheroids at days 4 to 6. Further in vitro culture resulted in bursting of the membrane of the microcapsules and cells deviated outward and continued to grow in flasks. The optimum injection time was found to be 5 d after tumor encapsulation. In the subcutaneous implantation model, there were no significant differences in terms of tumor volume between the encapsulated pancreatic tumor cells and cells alone and rate of tumor incidence. There was a significant difference in the rate of successful im- plantation between the cancer cell microencapsulation group and the single tumor-cell suspension group (100% vs 71.43%, respectively, P = 0.0489) in the orthotropic implantation model. The former method displayed an obvious advantage in tumor mass (4th wk: 0.0461 ± 0.0399 vs 0.0313 ± 0.021, t = -0.81, P = 0.4379; 8th wk: 0.1284 ± 0.0284 vs 0.0943 ± 0.0571, t = -2.28, respectively, P = 0.0457) compared with the latter in the orthotopic implantation model. CONCLUSION: Encapsulation of pancreatic tumor cells is a reliable method for establishing a pancreatic tumor animal model.

In vitro and in vivo evidence of metallopanstimulin-1 in gastric cancer progression and tumorigenicity

Purpose:The metallopanstimulin-1(MPS-1)gene is a growth factor-inducible gene,which is highly expressed in many human cancers and may be involved in the progression towards tumor malignancy.However,it is unclear whether MPS-1 plays any role in gastric cancer development or progression.Our studies were designed to clarify the MPS-1 expression pattern and to explore its potential role in gastric cancer.Experimental Design:The expression pattern of MPS-1 was determined in primary gastric cancer specimens and gastric cancer cell lines via immunohistochemistry and Western blotting.To investigate the functional significance of MPS-1 expression,three small interfering RNA(siRNA)expression plasmids were constructed and transfected into gastric cancer cell line SGC7901.The stable cell lines transfected with the siRNA targeting MPS-1 mRNA plasmids were selected and the biological features of these cells were examined.Results:MPS-1 was overexpressed in 86% of the gastric cancer tissues and all gastric cancer cells.In addition,MPS-1 expression was significantly increased and corresponded with the tumor-node-metastasis clinical stage,and was significantly higher in the late stage(P<0.01).The MPS-1 expression level was significantly decreased in the transfected cells with MPS-1-specific siRNA expression plasmid pRNAT-133.Furthermore,the stable transfected cancer cells exhibited an increase in the incidence of spontaneous apoptosis and a decrease in growth ability and tumorigenicity in nude mice.Conclusions:These results provide strong evidence that MPS-1 plays an important role in gastric cancer cell proliferation and development,and suggests that MPS-1 is a promising target for gastric cancer treatment.

Silencing invariant chain of DCs enhances Th1 response using small interfering RNA

RNA interference(RNAi),which causes the degradation of any RNA in a sequence specific manner,is a posttranscriptional gene silencing mechanism.Targeting the invariant chain(Ii)in DCs has been used as an approach to enhance antitumor immunity.It is demonstrated in this article that transfection of H-2(K)DCs with siRNA specific for Ii gene can significantly knock down Ii.When exposed to TNF-alpha,immature DCs transfected with Ii siRNA can differentiate into mature DCs without reducing viability or IL-12p70 production.Ii siRNA-treated H-2(K)DCs exhibited an increased allostimulatory capacity in a lymphocyte proliferation assay.Furthermore,Ii siRNA-transfected H-2(K)DCs enhanced Th1 responses by increasing IFN-gamma and decreasing IL-4 production,and much stronger cytotoxic activity was observed when DCs were co-transfected with Ii siRNA and an endogenous tumor antigen in vitro.Our findings indicate that silencing the Ii gene in DCs with siRNA may offer a potential approach to enhancing antitumor immunotherapy.

Machine-learning-assisted prediction of surgical outcomes in patients undergoing gastrectomy

Objective: Postoperative complications adversely affected the prognosis in patients with gastric cancer. This study intends to investigate the feasibility of using machine-learning model to predict surgical outcomes in patients undergoing gastrectomy.Methods: In this study, cancer patients who underwent gastrectomy at Shanghai Rui Jin Hospital in 2017 were randomly assigned to a development or validation cohort in a 9:1 ratio. A support vector classification(SVC) model to predict surgical outcomes in patients undergoing gastrectomy was developed and further validated.Results: A total of 321 patients with 32 features were collected. The positive and negative outcomes of postoperative complication after gastrectomy appeared in 100(31.2%) and 221(68.8%) patients, respectively. The SVC model was constructed to predict surgical outcomes in patients undergoing gastrectomy. The accuracy of 10-fold cross validation and external verification was 78.17% and 78.12%, respectively. Further, an online web server has been developed to share the SVC model for machine-learning-assisted prediction of surgical outcomes in patients undergoing gastrectomy in the future procedures, which is accessible at the web address:http://47.100.47.97:5005/r_model_prediction.Conclusions: The SVC model was a useful predictor for measuring the risk of postoperative complications after gastrectomy, which may help stratify patients with different overall status for choice of surgical procedure or other treatments. It can be expected that machine-learning models in cancer informatics research are possibly shareable and accessible via web address all over the world.

A STUDY ON THE TREATMENT OF GASTRIC CANCER BY CD GENE COMBINED WITH 5-FC IN VITRO AND IN VIVO

Objective: To study the killing effect of suicide gene CD on mouse gastric cancer. Methods: CD gene was transduced with the retroviral vector. The killing effect and bystander effect of CD gene on mouse gastric cancer cell line MFC were observed. The mouse gastric cancer model was used for in vivo study. The CD gene containing virus was injected into the tumors. The volumes of the tumors in every group were measured in time. Results: Significant killing effect and bystander effect were observed by CD gene in vitro, 70–80% cell death resulting from 20% of CD gene transduction. In vivo, CD/5-Fc caused tumor to diminution. Conclusion: CD/5-Fc system has significant killing effect on mouse gastric cancer

OPTIMIZATION OF ELECTROPORATION PARAMETERS FOR TRANSFECTION OF PLASMID DNA INTO MURINE BONE MARROW-DERIVED DENDRITIC CELL

Objective To explore the optimal electroporation parameters for transfection of plasmid DNA into murine bone marrow-derived dendritic cells. Methods Murine bone marrow-derived dendritic cells （DCs） were electroporated with plasmid DNA in varied conditions, such as electrical voltage, pulse time ,pre-electroporation cell condition and serum concentration in electrical buffer, lnverted fluorescence microscope and flow cytometer were used to determine the transfection efficiency. Some of the DCs genetically modified under different conditions were stained with trypan-blue and its viability was observed microscopically 48h after electroporation. Results Highest transfection efficiency （22.10%） could be reached when electrical voltage was 250V and pulse time was 20ms. Refreshing the culture medium pre-electroporation may help the cells recover more easily from gene transfer. Besides, electrical buffer containing serum may benefit the viability of DC after electroporation and temperature may has little influence on transfection efficiency. Conclusion Our observations demonstrated plasmid DNA could be efficiently transferred into murine bone marrow-derived DCs by electroporation. These data may helpful for cancer research related to murine DC transfection.

Recent progress in targeting the sialylated glycan-SIGLEC axis in cancer immunotherapy

Malignant tumors are complex structures composed of cancer cells and tumor microenvironmental cells.In this complex structure,cells cross-talk and interact,thus jointly promoting cancer development and metastasis.Recently,immunoregulatory molecule-based cancer immunotherapy has greatly improved treatment efficacy for solid cancers,thus enabling some patients to achieve persistent responses or cure.However,owing to the development of drug-resistance and the low response rate,immunotherapy against the available targets PD-1/PD-L1 or CTLA-4 has limited benefits.Although combination therapies have been proposed to enhance the response rate,severe adverse effects are observed.Thus,alternative immune checkpoints must be identified.The SIGLECs are a family of immunoregulatory receptors(known as glyco-immune checkpoints)discovered in recent years.This review systematically describes the molecular characteristics of the SIGLECs,and discusses recent progress in areas including synthetic ligands,monoclonal antibody inhibitors,and Chimeric antigen receptor T(CAR-T)cells,with a focus on available strategies for blocking the sialylated glycan-SIGLEC axis.Targeting glyco-immune checkpoints can expand the scope of immune checkpoints and provide multiple options for new drug development.

Emerging trends in clinical cancer genomic research

Academic activities are resuming now that the global COVID-19 pandemic has subsided.On 14-17 June 2023 the 15thInternational Gastric Cancer Congress(IGCC2023)of the International Gastric Cancer Association was held in Yokohama,Japan.More than 1300 experts from 44 countries discussed the hot issues pertaining to stomach cancer.