Objective: To investigate the effect of targeted silencing of DNA methyltransferase 3A(DNMT3A) on collagen deposition, proliferation and migration activity of mouse lung fibroblasts(PFs). Methods: In order to ensure the proliferation and migration activity of primary fibroblasts, the lung tissues of neonatal C57 suckling mice were taken, PFs were extracted after being sheared, and the morphology was observed and identified under the microscope. PFs cells were activated by 5 ng/ml TGF-β1for 24 h after cell attachment, and DNMT3A silencing model was constructed by small interfering RNA; The experiment was divided into control group, TGF-β1group, TGF-β1+ siRNA-NC group and TGF-β1+ siRNA-DNMT3A group. The protein expressions of DNMT3A, α-smooth muscle actin(α-SMA) and Collagen Ⅰ were detected by Western blot; Real time quantitative reverse transcription polymerase chain reaction(RT-qPCR) was used to detect the mRNA expression changes ofDNMT3A,α-SMAandCollagenⅠ. The proliferation ability of PFs was detected by CCK-8 and EdU staining; the migration ability of PFs was detected by scratch test and Transwell migration test. Results: Compared with the control group, TGF-β1induced the increase of DNMT3A in the activated PFs cell group(P<0.01), the protein and mRNA levels of fibrosis and proliferation related indicators α-SMA and Collagen Ⅰ also increased(allP<0.05), and the proliferation and migration ability of PFs increased(allP<0.000 1). Compared with the siRNA-NC group, the protein expression levels of DNMT3A(P<0.000 1) and related indicators α-SMA(P<0.01) and Collagen Ⅰ(P<0.01) significantly decreased in the DNMT3A silencing group by Western blot, and the mRNA levels ofDNMT3A,α-SMAandCollagenⅠby RT-qPCR also decreased(allP<0.001), and the proliferation(P<0.01) and migration ability(P<0.05) of PFs cells decreased compared with the control group. Conclusion Silencing DNMT3A can inhibit the deposition of collagen and the proliferation of PFs. DNMT3A can promote the proliferation and migration of PFs, and then promote the activation of PFs and the development of pulmonary fibrosis. This process may be regulated by DNA methylation modification.

Protein tyrosine phosphatase nonreceptor type 2 (PTPN2) is a promising target for sensitizing solid tumors to immune checkpoint blockades. However, the highly polar active sites of PTPN2 hinder drug discovery efforts. Leveraging small interfering RNA (siRNA) technology, we developed a novel glutathione-responsive nano-platform HPssPT (HA/PEIss@siPtpn2) to silence PTPN2 and enhance immunotherapy efficacy in hepatocellular carcinoma (HCC). HPssPT showed potent transfection and favorable safety profiles. PTPN2 deficiency induced by HPssPT amplified the interferon γ signaling in HCC cells by increasing the phosphorylation of Janus-activated kinase 1 and signal transducer and activator of transcription 1, resulting in enhanced antigen presentation and T cell activation. The nano-platform was also able to promote the M1-like polarization of macrophages in vitro. The unique tropism of HPssPT towards tumor-associated macrophages, facilitated by hyaluronic acid coating and CD44 receptor targeting, allowed for simultaneous reprogramming of both tumor cells and tumor-associated macrophages, thereby synergistically reshaping tumor microenvironment to an immunostimulatory state. In HCC, colorectal cancer, and melanoma animal models, HPssPT monotherapy provoked robust antitumor immunity, thereby sensitizing tumors to PD-1 blockade, which provided new inspiration for siRNA-based drug discovery and tumor immunotherapy.

Glioblastoma (GBM) is a highly aggressive primary brain tumor characterized by poor prognosis. Conventional chemo-radiotherapy demonstrates limited therapeutic efficacy and is often accompanied by significant side effects, largely due to factors such as drug resistance, radiation resistance, the presence of the blood-brain barrier (BBB), and the activation of DNA damage repair mechanisms. There is a pressing need to enhance treatment efficacy, with BRD4 identified as a promising target for increasing GBM sensitivity to therapy. Lacking small molecule inhibitors, BRD4 can be degraded using PROteolysis Targeting Chimera (PROTAC), thereby inhibiting DNA damage repair. To deliver PROTAC, SIAIS171142 (SIS) effectively, we designed a responsive nanocapsule, MPL_(SS)P@SIS, featuring GBM-targeting and GSH-responsive drug release. Modified with 1-methyl-l-tryptophan (MLT), nanocapsules facilitate targeted delivery of SIS, downregulating BRD4 and sensitizing GBM cells to radiotherapy and chemotherapy. After intravenous administration, MPL_(SS)P@SIS selectively accumulates in tumor tissue, enhancing the effects of radiotherapy and temozolomide (TMZ) by increasing DNA damage and oxidative stress. GSH activates the nanocapsules, triggering BRD4 degradation and hindering DNA repair. In mouse models, the nanosensitizer, combined with TMZ and X-ray irradiation, efficiently inhibited the growth of GBM. These findings demonstrate a novel PROTAC-based sensitization strategy targeting BRD4, offering a promising approach for effective GBM therapy.

Thalidomide (THA) is renowned for its potent anti-inflammatory properties. This study aimed to elucidate its underlying mechanisms in the context of Crohn's disease (CD) development. Mouse colitis models were established by dextran sulfate sodium (DSS) treatment. Fecal microbiota and metabolites were analyzed by metagenomic sequencing and mass spectrometry, respectively. Antibiotic-treated mice served as models for microbiota depletion and transplantation. The expression of forkhead box P3⁺ (FOXP3⁺) regulatory T cells (Tregs) was measured by flow cytometry and immunohistochemical assay in colitis model and patient cohort. THA inhibited colitis in DSS-treated mice by altering the gut microbiota profile, with an increased abundance of probiotics Bacteroides fragilis, while pathogenic bacteria were depleted. In addition, THA increased beneficial metabolites bile acids and significantly restored gut barrier function. Transcriptomic profiling revealed that THA inhibited interleukin-17 (IL-17), IL-1β and cell cycle signaling. Fecal microbiota transplantation from THA-treated mice to microbiota-depleted mice partly recapitulated the effects of THA. Specifically, increased level of gut commensal B. fragilis was observed, correlated with elevated levels of the microbial metabolite 3alpha-hydroxy-7-oxo-5beta-cholanic acid (7-ketolithocholic acid, 7-KA) following THA treatment. This microbial metabolite may stable FOXP3 expression by targeting the receptor FMR1 autosomal homolog 1 (FXR1) to inhibit autophagy. An interaction between FOXP3 and FXR1 was identified, with binding regions localized to the FOXP3 domain (aa238-335) and the FXR1 domain (aa82-222), respectively. Conclusively, THA modulates the gut microbiota and metabolite profiles towards a more beneficial composition, enhances gut barrier function, promotes the differentiation of FOXP3⁺ Tregs and curbs pro-inflammatory pathways.

Objective : To clarify the intrinsic link between a high-fat diet(HFD) and the pathological progression and prognosis of spinal cord injury(SCI) while preliminarily exploring the potential underlying mechanisms. Methods: SCI models were established in mice that were fed either a regular diet(RD) or HFD, with injury inflicted specifically on the T9-T12segments. Hematoxylin-Eosin(HE) staining, Masson staining, and Nissl staining were used to observe the local histological changes in SCI tissues. The basso, beattie, and bresnahan(BBB) score and footprint analysis were used to evaluate and compare hindlimb functional recovery after SCI in both RD and HFD mice.In vitroexperiments were conducted to identify key fatty acids in the HFD that exacerbate neuronal damage, whilein vivoexperiments assessed the effects of 2-bromopalmitate(2-BP), a palmitic acid inhibitor, on HFD-fed mice with SCI. Results : Compared to RD-fed mice, HFD-fed mice exhibited significantly larger lesion areas, more severe neuronal damage, and poorer hindlimb functional recovery after SCI. Palmitic acid was identified as the key fatty acid aggravating neuronal damage. Further more, inhibition of palmitoylation, mediated by palmitic acid, enhanced neuronal survival, promoted tissue repair, and improved hindlimb functional recovery in HFD-fed mice post-SCI. Conclusion HFD exacerbates pathological damage following SCI in mice through palmitic acid, impairing recovery. Palmitic acid-mediated palmitoylation is likely the main mechanism underlying this effect.

Objective To assess the feasibility of utilizing the ExacTracDynamic surface monitoring system(ETD)for setup and body surface monitoring in patients with thoracic tumors undergoing intensity-modulated radio-therapy(IMRT).Methods Patients receiving IMRT for thoracic tumors were included in this study.The enrolled patients were alternatively assigned to either conventional cross curve positioning(control group)or surface monitoring system-assisted positioning(experimental group).ETD X-ray images were utilized for calibration purposes prior to radiotherapy,enabling the determination of setup errors.A region of interest(ROI)was delineated on the body surface above the sternum,and real-time body surface monitoring was performed based on this ROI during radiotherapy.Post-radiotherapy X-ray images were obtained to verify patient position.Data regarding left-right(X),head-foot(Y),abdomen-back(Z),pitch,roll,and yaw directions were recorded and analyzed.Results A total of 60 patients were enrolled,with 754 fractions of radiotherapy in the control group and 718 fractions in the experimental group.The setup errors in the X and Z directions were significantly smaller in the experimental group compared to the control group(P<0.05).Moreover,there was a significant reduction in the number of setup errors≤0.50 cm for X,Y,and Z directions,as well as≤1.00° for Roll angle in the experimental group compared to the control group(P<0.05).Additionally,differences were observed between surface monitoring and X-ray image verification regarding position deviation along Y and Z directions(P<0.05),although these deviations remained within submillimeter levels on average.Conclusion Surface monitoring system-assisted positioning can enhance radiotherapy setup accuracy among thoracic tumor patients,particularly along X and Z directions.Furthermore,when setting ROI above sternum on body surface area,surface monitoring provides better reflection of target area's position deviation.

Objective:To treat the Crohn's disease(CD)patients with ustekinumab(UST),to eva-luate their clinical and endoscopic remission,and to evaluate their transmural response(TR)and trans-mural healing(TH)condition using intestinal ultrasonography(IUS).Methods:Retrospective analysis was made on patients diagnosed with CD in Peking University People's Hospital from January 2020 to Au-gust 2022,who were treated with UST for remission induction and maintenance therapy.All the patients were evaluated on both week 8 and week 16/20 after treatment,including clinical,biochemical indica-tors,colonoscopy and IUS examination.Results:A total of 13 patients were enrolled in this study,inclu-ding 11 males and 2 females.The minimum age was 23 years,the maximum age was 73 years and the mean age was 36.92 years.All the patients were in the active stage of disease before treatment,and the average Best Crohn's disease activity index(Best CDAI)score was 270.12±105.55.In week 8,the Best CDAI score of the patients decreased from 270.12±105.55 to 133.16±48.66(t=4.977,P＜0.001).Eight patients achieved clinical remission while 5 patients remained in the active stage.Nine patients underwent colonoscopy evaluation.The average simple endoscopic score for Crohn's disease(SES-CD)score decreased from 10.71±7.14 before treatment to 6.00±7.81(t=2.483,P=0.048)in week 16/20.Four patients achieved endoscopic remission while 5 patients did not.In week 8,5 pa-tients achieved TR,2 patients achieved TH,the other 6 patients did not get TR or TH.In week 16/20,6 patients achieved TR,3 patients achieved TH while the other 4 patients did not get TR or TH.There was no significant statistical difference in the TR effect of UST between small intestine and colon lesions(Fisher test,P＞0.999).The rate of UST transmural response in the patients who had had previous bio-logical agent therapy was lower than those with no previous biological agent therapy,but there was no sig-nificant statistical difference(Fisher test,P=0.491).Conclusion:After treatment of UST,the clinical and endoscopic conditions of the CD patients had been improved,and some patients could achieve clini-cal remission and endoscopic remission.UST had good TR and TH effects on CD.TR might appear in week 8,and the TR effect increased in week 16/20.There was no significant statistical difference in the TR effect between small intestine and colon lesions.TR effect of UST was better in the patients who had no previous biological agent therapy than those who had had other biological agents,but the result had no significant statistical difference.

Objective To explore the feasibility of automatic segmentation of clinical target volume(CTV)and organs at risk(OARs)for cervical cancer using AccuLearning(AL)based on geometric and dosimetric indices.Methods Seventy-five CT localization images with manual contouring data of postoperative cervical cancer were enrolled in this study.Sixty cases were randomly selected to trained to generate automatic segmentation model by AL,and the CTV and OARs of the remaining 15 cases were automatically contoured.Radiotherapy plans on the automatic segmentation contours were imported on the CT images of manual contours.The efficiency,Dice similarity coefficient(DSC),Hausdorff distance(HD)and dosimetric parameters were compared between the two methods.Results The time of automatic segmentation was significantly shorter than that of the manual contour(P<0.05).The DSC of all structures were≥0.87.The HD of bowel bag and rectum were about 10 mm,and that of the rest of OARs were less than 5 mm.CTV(D98,V90% ,V95% ,Dmean,HI),bowel bag(V50)and bladder(V50)had significant differences in dosimetric comparison(P<0.05).Conclusion The automatic segmentation model based on AL can improve the efficiency of radiotherapy.Automatic segmentation of OARs has the potential of clinical application,while that of CTV still needs to be further modified.

Objective To explore the correlation between intestinal dose and acute radiation enteritis(ARE)in patients with cervical cancer received concurrent chemoradiotherapy,and optimize the dose limit of intestinal tissue.Methods 158 cervical cancer patients received concurrent chemoradiotherapy from 2014 to 2019 were selected in this study.According to CTCAE 5.0,patients with ARE≥grade 2 were classified as ARE≥grade 2 group,otherwise classified as ARE0.7,P<0.05).Conclusions For patients with cervical cancer received concurrent chemoradiotherapy,the dose of bowelbag V5 and V40 should be considered to rationally optimize the dose of bowelbag in the radiotherapy plan,so as to reduce the incidence of ARE≥grade 2.