BACKGROUND:Periprosthetic joint infection is the most common cause of early failure after total knee replacement.The current methods of preventing periprosthetic joint infection by improving the surface of the prosthesis have limitations to varying degrees.OBJECTIVE:To construct a coating material that can stably improve the surface of the implant,prevent the initial floating bacterial infection of periprosthetic infection,and regulate the bone transfer function around the implant.METHODS:(1)Material preparation:YGF polypeptide(which promotes bone formation),LL-37 polypeptide(with antibacterial properties)and YGF+LL-37 composite peptide were prepared by Fmoc solid phase peptide synthesis technology.The titanium-based materials were immersed in the three polypeptide solutions for 2 hours to obtain YGF coating,LL-37 coating and composite peptide coating coated titanium sheets.(2)In vitro experiment:Uncoated titanium sheets and coated titanium sheets were co-cultured with Escherichia coli(or Staphylococcus aureus)and the colonies were counted by plate method.MC3T3 cells were inoculated on the surface of uncoated titanium sheet and coated titanium sheet,respectively.Alizarin red staining was used to observe the calcium salt deposition on the surface of the material.Western blot assay was used to detect the protein expression of RUNX2,osteocalcin,osteopontin,and bone morphogenetic protein 2.(3)Animal experiment:24 SD rats were randomly divided into three groups:the blank group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal;the control group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension;the experimental group(n=8)was implanted with composite peptide coated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension.After 5 weeks of implantation,micro-CT examination,hematoxylin-eosin staining and immunohistochemical staining of femur specimens were performed.RESULTS AND CONCLUSION:(1)In vitro experiment:Compared with uncoated titanium sheet and YGF coated titanium sheet,LL-37 coated and composite peptide coated titanium sheet could significantly inhibit the growth and reproduction of Escherichia coli and Staphylococcus aureus.Compared with uncoated titanium sheets and LL-37-coated titanium sheets,YGF-coated and composite peptide-coated titanium sheets could promote calcium salt deposition in osteoblasts and increase the protein expression of RUNX2,osteocalcin,osteopontin and bone morphogenetic protein 2.(2)Animal experiment:Micro-CT test showed that the control group had less bone mass than the blank group and the experimental group.Hematoxylin-eosin staining showed that there was a large amount of fibrous tissue around the nail channel in the control group,only a small amount of tissue fibrosis around the nail channel in the blank group,and only a small amount of tissue fibrosis around the nail channel in the experimental group.Immunohistochemical staining showed that the protein expression of interleukin 1β and tumor necrosis factor α in the control group was higher than that in the blank group and the experimental group,and the expression of osteocalcin,RUNX2 and osteopontin in the experimental group was higher than that in the blank group and the control group.(3)The results show that the titanium-based material coated with YGF+LL-37 composite peptide coating has good antibacterial ability and can promote bone transfer around the implant.

OBJECTIVE:Based on different algorithms of machine learning,the prediction model of lumbar disc herniation has become a trend and hot spot in the development of precision medicine.However,there is limited evidence on the reporting quality and methodological quality of prediction models of lumbar disc herniation outcomes using machine learning.This article is aimed to explore the performance of machine learning algorithms in predicting the prognosis of lumbar disc herniation by comprehensively analyzing the report quality and risk of bias of previous studies that developed and validated prognosis prediction models based on machine learning through a comprehensive literature search,in order to explore the performance of machine learning algorithms in predicting the prognosis of lumbar disc herniation.METHODS:The databases of CNKI,WanFang,VIP,SinOMED,PubMed,Web of Science,Embase,and The Cochrane Library were searched by computer.Studies on the use of machine learning to develop(and/or validate)prognostic prediction models for lumbar disc herniation were collected from the inception of the database to December 31,2023.Two researchers independently screened the literature,extracted data,and assessed the risk of bias of the included studies.The reporting quality and risk of bias of the included studies were assessed by the Multivariable Transparent Reporting of Predictive Models(TRIPOD)statement and the Predictive Model Risk of Bias Assessment Tool(PROBAST).The results of the evaluation were analyzed using descriptive statistics and visual charts.RESULTS:(1)A total of 23 articles were included,and the TRIPOD compliance of each study ranged from 11％to 87％,with a median compliance of 54％.The quality of reporting of titles,detailed descriptions of treatment measures,blinding of predictors,handling of missing data,details of risk stratification,specific procedures for enrollment,model interpretation,and model performance was mostly poor,with TRIPOD adherence rates ranging from 4％to 35％.(2)Of all included studies,61％had a high risk of bias and 39％had an unclear overall risk of bias.The area under the curve,accuracy,sensitivity and specificity were used to evaluate the performance of the model.The areas under the curve of 20 models were reported,ranging from 0.561 to 0.999.Three models reported the accuracy of the model,ranging from 82.07％to 89.65％.(3)Among all included studies,the statistical analysis domain was most often assessed as having a high risk of bias,mainly due to the small number of valid samples,the selection of predictors based on univariate analysis and the lack of calibration and discrimination assessment of the model in the study.CONCLUSION:These results indicate that machine learning can achieve good predictive ability in the development and validation of prognostic models for lumbar disc herniation.The commonly used algorithms include regression algorithm,support vector machine,decision tree,random forest,artificial neural network,naive Bayes and other algorithms.Reasonable algorithms combined with clinical practice can improve the accuracy of prognosis prediction of lumbar disc herniation.However,the reporting and methodological quality of prognosis prediction models based on machine learning are poor,the prediction performance of different models varies greatly,and the generalization and extrapolation of research models are unclear.There is an urgent need to improve the design,implementation and reporting of such studies.To promote the application of machine learning in the clinical practice of lumbar disc herniation prediction models,it is necessary to comprehensively consider various predictors related to the prognosis of the disease before modeling,and strictly follow the relevant standards of PROBAST tool during modeling.

BACKGROUND:Periprosthetic joint infection is the most common cause of early failure after total knee replacement.The current methods of preventing periprosthetic joint infection by improving the surface of the prosthesis have limitations to varying degrees.OBJECTIVE:To construct a coating material that can stably improve the surface of the implant,prevent the initial floating bacterial infection of periprosthetic infection,and regulate the bone transfer function around the implant.METHODS:(1)Material preparation:YGF polypeptide(which promotes bone formation),LL-37 polypeptide(with antibacterial properties)and YGF+LL-37 composite peptide were prepared by Fmoc solid phase peptide synthesis technology.The titanium-based materials were immersed in the three polypeptide solutions for 2 hours to obtain YGF coating,LL-37 coating and composite peptide coating coated titanium sheets.(2)In vitro experiment:Uncoated titanium sheets and coated titanium sheets were co-cultured with Escherichia coli(or Staphylococcus aureus)and the colonies were counted by plate method.MC3T3 cells were inoculated on the surface of uncoated titanium sheet and coated titanium sheet,respectively.Alizarin red staining was used to observe the calcium salt deposition on the surface of the material.Western blot assay was used to detect the protein expression of RUNX2,osteocalcin,osteopontin,and bone morphogenetic protein 2.(3)Animal experiment:24 SD rats were randomly divided into three groups:the blank group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal;the control group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension;the experimental group(n=8)was implanted with composite peptide coated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension.After 5 weeks of implantation,micro-CT examination,hematoxylin-eosin staining and immunohistochemical staining of femur specimens were performed.RESULTS AND CONCLUSION:(1)In vitro experiment:Compared with uncoated titanium sheet and YGF coated titanium sheet,LL-37 coated and composite peptide coated titanium sheet could significantly inhibit the growth and reproduction of Escherichia coli and Staphylococcus aureus.Compared with uncoated titanium sheets and LL-37-coated titanium sheets,YGF-coated and composite peptide-coated titanium sheets could promote calcium salt deposition in osteoblasts and increase the protein expression of RUNX2,osteocalcin,osteopontin and bone morphogenetic protein 2.(2)Animal experiment:Micro-CT test showed that the control group had less bone mass than the blank group and the experimental group.Hematoxylin-eosin staining showed that there was a large amount of fibrous tissue around the nail channel in the control group,only a small amount of tissue fibrosis around the nail channel in the blank group,and only a small amount of tissue fibrosis around the nail channel in the experimental group.Immunohistochemical staining showed that the protein expression of interleukin 1β and tumor necrosis factor α in the control group was higher than that in the blank group and the experimental group,and the expression of osteocalcin,RUNX2 and osteopontin in the experimental group was higher than that in the blank group and the control group.(3)The results show that the titanium-based material coated with YGF+LL-37 composite peptide coating has good antibacterial ability and can promote bone transfer around the implant.

OBJECTIVE:Based on different algorithms of machine learning,the prediction model of lumbar disc herniation has become a trend and hot spot in the development of precision medicine.However,there is limited evidence on the reporting quality and methodological quality of prediction models of lumbar disc herniation outcomes using machine learning.This article is aimed to explore the performance of machine learning algorithms in predicting the prognosis of lumbar disc herniation by comprehensively analyzing the report quality and risk of bias of previous studies that developed and validated prognosis prediction models based on machine learning through a comprehensive literature search,in order to explore the performance of machine learning algorithms in predicting the prognosis of lumbar disc herniation.METHODS:The databases of CNKI,WanFang,VIP,SinOMED,PubMed,Web of Science,Embase,and The Cochrane Library were searched by computer.Studies on the use of machine learning to develop(and/or validate)prognostic prediction models for lumbar disc herniation were collected from the inception of the database to December 31,2023.Two researchers independently screened the literature,extracted data,and assessed the risk of bias of the included studies.The reporting quality and risk of bias of the included studies were assessed by the Multivariable Transparent Reporting of Predictive Models(TRIPOD)statement and the Predictive Model Risk of Bias Assessment Tool(PROBAST).The results of the evaluation were analyzed using descriptive statistics and visual charts.RESULTS:(1)A total of 23 articles were included,and the TRIPOD compliance of each study ranged from 11％to 87％,with a median compliance of 54％.The quality of reporting of titles,detailed descriptions of treatment measures,blinding of predictors,handling of missing data,details of risk stratification,specific procedures for enrollment,model interpretation,and model performance was mostly poor,with TRIPOD adherence rates ranging from 4％to 35％.(2)Of all included studies,61％had a high risk of bias and 39％had an unclear overall risk of bias.The area under the curve,accuracy,sensitivity and specificity were used to evaluate the performance of the model.The areas under the curve of 20 models were reported,ranging from 0.561 to 0.999.Three models reported the accuracy of the model,ranging from 82.07％to 89.65％.(3)Among all included studies,the statistical analysis domain was most often assessed as having a high risk of bias,mainly due to the small number of valid samples,the selection of predictors based on univariate analysis and the lack of calibration and discrimination assessment of the model in the study.CONCLUSION:These results indicate that machine learning can achieve good predictive ability in the development and validation of prognostic models for lumbar disc herniation.The commonly used algorithms include regression algorithm,support vector machine,decision tree,random forest,artificial neural network,naive Bayes and other algorithms.Reasonable algorithms combined with clinical practice can improve the accuracy of prognosis prediction of lumbar disc herniation.However,the reporting and methodological quality of prognosis prediction models based on machine learning are poor,the prediction performance of different models varies greatly,and the generalization and extrapolation of research models are unclear.There is an urgent need to improve the design,implementation and reporting of such studies.To promote the application of machine learning in the clinical practice of lumbar disc herniation prediction models,it is necessary to comprehensively consider various predictors related to the prognosis of the disease before modeling,and strictly follow the relevant standards of PROBAST tool during modeling.

ObjectiveTo explore the potential mechanism of Weicanqing Formula （微残清方， WF） combined with chemotherapy in treating acute myeloid leukemia （AML） based on malic enzyme 2 （ME2）-mediated bone marrow immune-metabolic homeostasis and . MethodsSixty-five male C57BL/6N mice were randomly divided into control group， model group， WF group， chemotherapy group， and the combination group （WF plus chemotherapy）， with 13 mice per group. Except for the control group， mice were injected with C1498 cells （appro-ximately 1×10⁶ cells per mouse） via the tail vein on day 1 to establish an AML model. Starting from day 8， mice in the chemotherapy group and the combination group were administered with cytarabine at 30 mg/（kg·d） via subcutaneous injection， once daily for 3 consecutive days； WF group and the combination group received WF at 7.54 g/（kg·d） by gavage， once daily for 21 consecutive days. On days 1， 7， 14， 21 and 28， hemoglobin （Hb） and white blood cell （WBC） levels were determined in each group. On day 28， Giemsa staining was used to observe morphological changes in bone marrow cells. Flow cytometry was employed to detect the expression levels of bone marrow T lympthocyte subsets， including CD8⁺， CD4⁺， and regulatory T lymphocytes （Treg）. The contents of glutamine （Gln）， nicotinamide adenine dinucleotide phosphate （NADP⁺）， and reduced nicotinamide adenine dinucleotide phosphate （NADPH） in bone marrow were determined using visible spectrophotometry. Adenosine triphosphate （ATP） concentration in bone marrow was measured by chemiluminescence assay. The mRNA expression of malic enzyme 2 （ME2） in bone marrow was detected by RT-qPCR， and the protein expression level of ME2 was determined by Western blotting. ResultsCompared to the control group， the model group showed decreased Hb levels on day 14， 21， and 28， and increased WBC levels on day 7， 14， 21， and 28 （P＜0.05）. On day 28， bone marrow CD8⁺ and CD8⁺/CD4⁺ levels decreased， while Treg cells， ATP， Gln， NADP⁺， NADPH， ME2 mRNA， and their corresponding protein levels increased （P＜0.05）. Compared to the model group， the chemotherapy group and the combination group both exhibited reduced Hb level on day 14， 21 and 28， as well as the increased WBC level； the combination group showed increased CD8⁺ level， decreased Treg， ATP， Gln， and NADPH content， as well as reduced ME2 mRNA expression and protein levels （P＜0.05）. Compared to the chemotherapy group， the combination group showed significantly increased Hb level on days 21 and 28， and increased WBC level on day 28 （P＜0.05）. Bone marrow smear pathology revealed that， in the model group， myeloid blast cells exhibited cytoplasmic vacuoles indicative of abnormal metabolic activity. In contrast， both the chemotherapy group and the combination group showed large numbers of metamyelocytes and band neutrophils， with only a few immature granulocytic blast cells observed. ConclusionWF may improve the prognosis of AML when used as an adjunct to chemotherapy by modulating ME2 expression， inhibiting metabolic energy competition within the bone marrow microenvironment， and reshaping the distribution of T lymphocyte subsets in the bone marrow.

Objective:To evaluate the efficacy and safety of fecal microbiota transplantation (FMT) for treating functional constipation, analyze the incidence of, and factors that influence, adverse events, and provide scientific evidence for optimizing FMT treatment.Methods:This retrospective, multicenter, single-arm, pre–post real-world study included 1529 patients with functional constipation from four clinical centers. Eligibility criteria comprised meeting the diagnostic criteria for functional constipation, having undergone at least one FMT treatment, complete pre- and post-treatment data available, and age ≥18 years. Patients who had received other interventions affecting gut function within 1 month before treatment and those with severe organic diseases or immune deficiencies were excluded. Applying the above criteria yielded 1529 eligible patients with functional constipation from four medical centers (1405 from the Shanghai Tenth People's Hospital Affiliated to Tongji University, 20 from the Central Hospital of Wuhan, 67 from the Shanxi Bethune Hospital and 37 from the Longgang District People's Hospital of Shenzhen). The study cohort comprised 746 male (48.8%) and 783 female patients (51.2%) of mean age (51.4 ± 17.4) years, mean body mass index (26.4 ± 4.9) kg/m2, and mean duration of disease (15.0 ± 8.3) years. The primary outcomes were the incidence, types, and severity of adverse reactions during treatment, and their impact on patients' quality of life. Secondary outcomes included: (1) the efficacy of FMT in treating constipation. This was assessed based on changes in Patient Assessment of Constipation Symptoms (PAC-SYM) scores, where higher score indicates worse symptom. (2) Subjective satisfaction, evaluated through questionnaires or rating scales, reflecting patients' acceptance of and satisfaction with the treatment, with scores ranging from 1 to 5, where higher scores indicated greater satisfaction. Paired t-tests and Wilcoxon signed-rank tests were used to evaluate changes in symptom scores and biochemical indicators before and after treatment. Logistic regression was performed to analyze factors influencing adverse events, and subgroup analyses to explored differences in efficacy between patient groups.Results:In this cohort of 1529 patients with functional constipation, adverse reactions were primarily mild to moderate (1048/1529,68.5%). They comprised fever in 54 patients (3.5%), dizziness or fatigue in 218 (14.3%), throat discomfort in 806 (52.7%), nausea and vomiting in 166 (10.9%), and abdominal distension or pain in 415 (27.1%). According to multivariate logistic regression analysis, PAC-SYM scores were associated with the rate of adverse reactions, higher scores indicating a lower risk (OR = 0.958, 95% CI: 0.923–0.993, P=0.021). Among the 1529 patients, 274 (17.9%) underwent two or more treatment courses. After one treatment course, the patients' PAC-SYM scores decreased from (37.7 ± 3.2) pre-treatment to (23.7 ± 8.6) (mean difference 14.0 ± 9.1). PAC-SYM scores decreased by (20.7 ± 7.7) after two courses of FMT, and by (19.4 ± 6.3) after three courses. After treatment, 50.7%(775/1529) of patients reported satisfaction scores of ≥4. Adverse reactions impacted satisfaction; specifically, dizziness/fatigue, throat discomfort, and abdominal distension/pain were significantly associated with satisfaction (all P < 0.05). Conclusions:FMT achieved good relief of symptoms of functional constipation and multiple treatment courses have a cumulative effect. Adverse reactions, mainly dizziness/fatigue, throat discomfort, and abdominal distension/pain, had significant negative impacts on patient satisfaction.

Objective:To investigate the related factors for unexpected positive intraoperative cultures (UPC) in patients undergoing aseptic hip revision and the long-term prosthesis survival rate in such patients.Methods:A retrospective cases series analysis was conducted in 397 patients who underwent aseptic hip revision surgery at the Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University from January 2012 to December 2021. There were 225 females and 172 males with an age ( M(IQR)) of 58(23) years (range:21 to 89 years) and a body mass index (BMI) of 25(6) kg/m 2 (range:15 to 39 kg/m 2). Based on the culture results of intraoperative specimens, patients were divided into culture-positive group (32 cases) and culture-negative group (365 cases). The clinical data were analyzed including gender, age, BMI, preoperative C-reactive protein, preoperative erythrocyte sedimentation rate, American Society of Anesthesiologists(ASA) classification, preoperative urinary bacteria, preoperative hypoproteinemia; comorbidities of diabetes mellitus, anemia, chronic obstructive pulmonary disease, cerebral infarction; history of allergy to antibiotics, smoking, drinking, previous prosthetic dislocation, previous surgical intervention; and time from symptom onset to admission, duration of surgery, etc. A univariate analysis was performed by Mann-Whitney U orχ2 test and the independent risk factors were identified by including the independent variables with P<0.20 in the univariate analysis in a logistic regression analysis of dichotomous variables. The study outcomes were defined as :(1) re-surgical treatment for any reason; (2)symptoms of infection such as sinus and incision seepage; (3) persistent excessive hip pain.The Kaplan-Meier survival curve was plotted using the study outcome of any cause as the endpoint event, and the log-rank test was used to compare the 10-year survival rate of the prosthesis in the culture-negative group with that in the culture-positive group. Results:Univariate analysis showed statistically significant differences between the culture-negative and culture-positive groups when comparing gender, BMI, ASA classification, and preoperative urinary bacterial results ( χ2=2.368, P=0.124; χ2=-1.648, P=0.098; χ2=14.128, P=0.003; and χ2=7.384, P=0.007). Logistic regression analysis showed that male, ASA classification Ⅳ, and positive preoperative urinary bacteria were independent risk factors for the development of UPC during aseptic hip revision( OR=2.35,95% CI:1.08 to 5.36, P=0.040; OR=37.32,95% CI:1.80 to 1 810.63, P=0.030; OR=4.11,95% CI:1.40 to 11.12, P=0.012). The follow-up time of the 397 patients included in this study was 70 (134) months (range:12 to 146 months). The Kaplan-Meier survival curves showed that the 10-year survival rates of the prostheses in the culture-negative and culture-positive groups were 95.7% and 75.0%, respectively. There was no statistically significant difference in the 10-year survival rate comparing the two groups ( P=0.661). Conclusions:UPC is more likely to occur in patients undergoing hip revision due to noninfectious factors in those who are male, have positive preoperative urinary bacteria, and have an ASA classification of Ⅳ. Intraoperative specimen culture results (negative or positive) do not affect 10-year prosthesis survival rate after hip revision.

Objective:To investigate the diagnostic efficacy of intraoperative direct sonication in periprosthetic joint infection (PJI).Methods:This is a retrospective case series study. The clinical data of 490 patients with PJI or aseptic prosthesis loosening after hip or knee arthroplasty admitted to the Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University from January 2018 to December 2023 were retrospectively analyzed. There were 209 male cases, 281 female cases, aged ( M(IQR)) 63 (19) years (range: 15 to 89 years). There were 328 cases of PJI (123 cases of traditional sonication, 205 cases of intraoperative direct sonication, and 204 cases had simultaneous intraoperative synovial fluid), and 162 patients of aseptic loosening (89 cases of traditional sonication, 73 cases of intraoperative direct sonication, and 96 cases had simultaneous intraoperative synovial fluid). The method of traditional sonication: the prosthesis components were placed in a sterile container, vortexed for 30 seconds, then placed in an ultrasound bath to sonication (frequency:(40±2) kHz, power density:(0.22±0.04) W/cm2) for 5 minutes, vortexed again for 30 seconds, and the resulting sonicate fluid was extracted for culture. The method of intraoperative direct sonication: during the operation, the surgical area, the prosthesis and the tissues around the prosthesis which were placed in a sterile container were respectively subjected to sonication for 5 minutes using a portable handheld ultrasonic cell disruptor device (frequency: 25 kHz, power density:(0.22±0.04) W/cm2), and the fluids before and after sonication were extracted for culture. The method of intraoperative synovial fluid: during the operation, the joint capsule was incised, and the synovial fluid was extracted under direct vision for culture. The sensitivity, specificity, positive and negative predictive values, Youden index, the effect of preoperative antimicrobial agents on culture results, and culture duration for different culture methods. Receiver operating characteristic (ROC) curves were plotted, and the diagnostic efficacy of these methods for PJI was compared using the χ2 test, the Wilcoxon signed-rank test, and other appropriate statistical methods. Results:The sensitivity of intraoperative direct sonication was significantly higher than that of intraoperative synovial fluid culture (89.8%(184/205) vs.56.9%(116/204), χ2=44.457, P<0.01) and traditional sonication (89.8%(184/205) vs.66.7%(82/123), χ2=121.588, P<0.01). However, its specificity was lower compared to intraoperative synovial fluid (87.5%(64/73) vs. 99.0%(95/96), χ2=9.491, P=0.002). The culture duration for intraoperative direct sonication was shorter than for intraoperative synovial fluid 87.0 (41.8) hours vs. 112.5 (78.5) hours, Z=-5.121, P<0.01) and traditional sonication (87.0 (41.8) hours vs. 119.0 (67.5) hours, Z=-7.119, P<0.01). Gram-positive bacteria (predominantly Staphylococcus aureus and Staphylococcus epidermidis) were the most common isolates across all three culture methods. Furthermore, intraoperative direct sonication was more likely to detect polymicrobial infections compared to traditional sonication (38.6% vs. 2.4%, χ2=37.223, P<0.01) and intraoperative synovial fluid (38.6% vs. 0.9%, χ2=55.527, P<0.01). The ROC curve revealed that the area under the curve of intraoperative direct sonication,intraoperative synovial fluid culture and traditional sonication were 0.886 (95% CI:0.843 to 0.930), 0.779 (95% CI:0.743 to 0.815) and 0.788 (95% CI: 0.736 to 0.839). Conclusions:Compared with intraoperative synovial fluid and traditional sonication, intraoperative direct sonication has excellent sensitivity, the shortest appropriate culture duration for pathogenic bacteria, and it is more likely to diagnose PJI patients with polymicrobial infections, having better diagnostic efficacy in the diagnosis of PJI.

Objective To investigate the role and primary mechanism of a novel fusion gene RELCH-RET in driving the malignant transformation of normal human bronchial epithelial(HBE)cells.Methods Based on retrospective clinical data from 456 non-small cell lung cancer(NSCLC)patients admitted in the Second Affiliated Hospital of Army Medical University from January 2019 to June 2022,a fusion gene,RELCH-RET,was identified as a research target.Three cell models were established:negative control(HBE VC,transfected with empty lentiviral vector),RET control(HBE RET,transfected with lentiviral overexpression vector of Flag-RET),and experimental group(HBE RELCH-RET,transfected with lentiviral overexpression vector of Flag-RELCH-RET).MTS assay and Transwell assay were used to detect cell proliferation and migratory and invasive abilities.In vivo tumorigenicity of the 3 cell models was assessed in 15 female non-obese diabetic/severe combined immunodeficiency(NOD/SCID)mice(SPF grade,4 weeks old,weighing 15.1±0.4 g)via subcutaneous xenograft experiments,with 5 animals in each group.Western blotting was employed to detect the autophosphorylation of RET(Y905)and the phosphorylation of downstream signaling proteins ERK1/2,EGFR(Y845)and STAT3(Y705).Dimerization and multimerization status of RELCH-RET were analyzed by chemical cross-linking(DTME treatment)in combination with Western blotting,with the reversibility being confirmed through de-cross-linking experiments.Results There were 3 cases carrying RELCH-RET fusion gene screened out from the 469 NSCLC patients.Compared with the HBE VC and HBE RET groups,the HBE RELCH-RET group exhibited significantly enhanced cell proliferation(P<0.01),and acquired migratory and invasive abilities(P<0.01),while the control groups did not demonstrate the abilities.In the mouse xenograft tumor model,HBE cells stably expressing RELCH-RET developed significant tumor nodules(P<0.001),whereas the control groups(empty vector and wild-type RET)failed to exhibit detectable tumor growth.Western blotting revealed that RELCH-RET could induce the autophosphorylation of the RET tyrosine residue(Y905)and significantly up-regulate the phosphorylation levels of ERK1/2,EGFR(Y845),and STAT3(Y705)proteins.Chemical cross-linking combined with Western blot analysis demonstrated that RELCH-RET formed a dimer(～170 kDa)in HBE cells,which is reversibly dissociated into monomers upon decross-linking treatment.Conclusion The novel fusion gene RELCH-RET,promotes ligand-independent dimerization/oligomerization,thereby mediating RET autophosphorylation,subsequently activates the downstream typical RET signaling pathway and ultimately drives the malignant transformation of normal HBE cells.

Objective To elucidate the effects of miR-616 on the malignant biological processes of osteosarcoma and to preliminarily explore its potential mechanisms.Methods In situ hybridization(ISH)was employed to analyze miR-616 expression in 11 paraffin-embedded osteosarcoma specimens collected in our department during January 2018 to December 2019.Quantitative real-time PCR(qRT-PCR)was used to compare the mRNA expression level of miR-616 in the osteoblast cell line hFOB1.19 and osteosarcoma cell lines 143B and HOS.Stable cell lines with miR-616 knockdown or overexpression were established via lentiviral transfection in 143B and HOS cells.Cell proliferation and apoptosis were detected by flow cytometry,while cell invasion and migration were assessed using Transwell and colony formation assays,respectively.To evaluate the effect of miR-616 on tumor growth in vivo,10 female nude mice(4 weeks old,weighing 18～20 g)were randomized into a control group and a miR-616 overexpression group.After the xenograft tumor model was constructed,the growth of subcutaneous tumors was monitored.Finally,next-generation sequencing and a dual-luciferase reporter assay were performed to identify the target genes of miR-616.Results ISH results showed that miR-616 expression was up-regulated in osteosarcoma tissues than adjacent tissues,and primarily localized in the cytoplasm.qRT-PCR confirmed that miR-616 level was significantly higher in 143B and HOS cells than hFOB1.19 cells(P<0.05).In vitro experiments revealed that miR-616 overexpression enhanced the proliferation,migration and invasion,while suppressing apoptosis in 143B and HOS cells(P<0.01).Conversely,miR-616 knockdown weakened these malignant phenotypes(P<0.05),with miR-616-3p showing a stronger effect on apoptosis than miR-616-5p.Animal experiments demonstrated that the tumor weight in the miR-616 overexpression group was significantly greater than that of the control group(98.00±17.22 vs 33.60±8.08 mg,P<0.01).Furthermore,KLF2 was identified and confirmed as a direct target of miR-616.Conclusion MiR-616 promotes malignant biological behaviors in osteosarcoma,and its expression level indicates that it may serve as a potential therapeutic target.