BACKGROUND:We have successfully established an animal model of small ear pig in southern Yunnan province with internal tension relieving technique combined with autologous Achilles tendon for anterior cruciate ligament reconstruction,and verified the stability and reliability of the model.However,whether internal tension relieving technique can promote the ligamentalization process of autologous Achilles tendon graft has not been studied. OBJECTIVE:To investigate the differences in the process of ligamentalization between conventional reconstruction and internal reduction reconstruction of the anterior cruciate ligament by gross view,histology and electron microscopy. METHODS:Thirty adult female small ear pigs in southern Yunnan province were selected.Anterior cruciate ligament reconstruction was performed on the left knee joint with the ipsilateral knee Achilles tendon(n=30 in the normal group),and anterior cruciate ligament reconstruction was performed on the right knee joint with the ipsilateral knee Achilles tendon combined with the internal relaxation and enhancement system(n=30 in the relaxation group).The autogenous right forelimb was used as the control group;the anterior cruciate ligament was exposed but not severed or surgically treated.At 12,24,and 48 weeks after surgery,10 animals were sacrificed,respectively.The left and right knee joint specimens were taken for gross morphological observation to evaluate the graft morphology.MAS score was used to evaluate the excellent and good rate of the ligament at each time point.Hematoxylin-eosin staining was used to evaluate the degree of ligament graft vascularization.Collagen fibers and nuclear morphology were observed,and nuclear morphology was scored.Ultrastructural remodeling was evaluated by scanning electron microscopy and transmission electron microscopy. RESULTS AND CONCLUSION:(1)The ligament healing shape of the relaxation group was better at various time points after surgery,and the excellent and good rate of MAS score was higher(P<0.05).Moreover,the relaxation group could obtain higher ligament vascularization score(P<0.05).(2)The arrangement of collagen bundles and fiber bundles in the two groups gradually tended to be orderly,and the transverse fiber connections between collagen gradually increased and thickened,suggesting that the strength and shape degree of the grafts were gradually improved,but the ligament remodeling in the relaxation group was always faster than that in the normal group at various time points after surgery.(3)The diameter,distribution density,and arrangement degree of collagen fibers in the relaxation group were better than those in the normal group at all time points,especially in the comparison of collagen fiber diameter between and within the relaxation group(P<0.05).

Arginine methylation is a critical post-translational modification that plays multifaceted biological functions. However, the manipulation of protein arginine methylation largely depends on genetic or pharmaceutic inhibition of the regulatory enzymes, protein arginine methyltransferases (PRMTs), or non-methylation substitution of corresponding arginine residue to lysine or alanine of protein of interest (POI), which inevitably affects other substrates, or disrupts the structure of POI. Thus, it urges an approach to specifically modulate the arginine methylation of a POI under physiological conditions. To this end, we report the discovery of a methylation tagging system (MeTAG), that enables targeted modification of protein arginine methylation. Through bridging the methyltransferase PRMT5 proximity to a POI, MeTAG facilitates the arginine methylation of POIs, including known arginine methylated proteins, androgen receptor (AR) and protein kinase B (AKT), as well as a neo-substrate E1A binding protein (p300), in a reversible and PRMT5-dependent manner. Moreover, MeTAG can regulate downstream signaling in a methylation dependent manner, leading to downregulation of PSMA mRNA level and activation of AKT. Therefore, MeTAG represents a feasible approach to modulate protein methylation and thereby perturbs protein function in biological and therapeutic contexts.

Objective:To elucidate the prognostic differences and risk factors associated with different patterns of recurrence and metastasis following pancreatic cancer (PC) resection.Methods:This is a retrospective case series study. Clinicopathological data and follow-up information were retrospectively collected from 210 patients who underwent surgery for PC at the Department of Hepatobiliary and Pancreatic Surgery, Peking University First Hospital, between January 2014 and December 2023. There were 114 males and 96 females; the age was (64.5±10.3) years (range: 29 to 89 years). Survival functions based on different times to recurrence and metastasis and different patterns of recurrence and metastasis were estimated using the Kaplan-Meier method, and survival differences among groups were compared using the Log-rank test. Identifying the optimal cutoff for time to postoperative recurrence/metastasis predicting overall survival (OS) in pancreatic cancer patients via the minimum p-value approach. Univariate and multivariate Cox regression analyses were performed to identify independent risk factors affecting OS following pancreatectomy.Results:A total of 210 patients met the inclusion and exclusion criteria. Among them, 71 patients remained free of recurrence and metastasis, while 139 developed recurrence and metastasis. The patterns included local recurrence ( n=34), liver metastasis ( n=39), lung metastasis ( n=11), peritoneal metastasis ( n=13), multiple sites metastasis ( n=38), bone metastasis ( n=3), and kidney metastasis ( n=1). OS was significantly shorter in the group with postoperative recurrence and metastasis compared to the group without recurrence/metastasis (23.07 months vs.not reached, P<0.01). The optimal cut-off time distinguishing early from late recurrence and metastasis was 13 months. There was a significant difference in post-recurrence survival between patients with early and late recurrence and metastasis (16.03 months vs. 52.40 months, P=0.009). The Kaplan-Meier survival curve showed that different postoperative recurrence and metastasis patterns had different impacts on OS, with lung metastasis showing the best prognosis compared to local recurrence, liver metastasis, peritoneal metastasis, and multiple sites metastasis ( P<0.01). Multivariate Cox analysis revealed that Eastern Cooperative Oncology Group (ECOG) score 1, postoperative carcinoembryonic antigen (CEA) ≥15 μg/L, poor tumor differentiation, postoperative local recurrence, liver metastasis, peritoneal metastasis, and multiple sites metastases are independent risk factors for postoperative recurrence and metastasis (all P<0.05). Conclusions:Considerable prognostic heterogeneity exists in postoperative PC patients depending on the site and pattern of recurrence or metastasis. Specifically, lung metastasis portends a significantly more favorable prognosis than liver metastasis, peritoneal metastasis, local recurrence, or multiple sites metastases. ECOG score 1, postoperative CEA≥15 μg/L, poor tumor differentiation, postoperative local recurrence, liver metastasis, peritoneal metastasis, and multiple sites metastases are independent risk factors for OS in postoperative PC patients.

Objective·To determine hyaluronan(HA)expression in the endocrine-resistant microenvironment of estrogen receptor-positive(ER+)breast cancer and elucidate its impact on the acquired resistance.Methods·Chemiluminescent immunoassay was used to quantify HA levels in the culture supernatants of fulvestrant-resistant breast cancer cells.An immunofluorescence(IF)assay was performed to visualize the colocalization of CD44 and HA in MCF7/FulR cells.Using an established adaptive endocrine-resistant breast cancer mouse model,HA expression in resistant breast cancer tissues was assessed by immunohistochemistry(IHC)assay.Single-cell RNA sequencing(scRNA-seq)and RNA sequencing(RNA-seq)were conducted to examine transcriptomic profiles and alterations in HA-related genes in resistant breast cancer cells.Flow cytometry(FCM)was utilized to measure the proportion of CD44+CD24-cells in MCF7/FulR.The correlation between HA synthesis genes and cell stemness was investigated in clinical ER+breast cancers from GEO data sets.Hyaluronidase(HAase)treatment was applied to remove the"HA coat",and RT-qPCR and Western blotting analysis were carried out to monitor changes in stemness-related molecules.CCK-8 assays,flow cytometry(FCM),and Hoechst 33258 staining were performed to determine changes in apoptosis and fulvestrant efficiency after HAase treatment.Results·IF results revealed that compared with MCF7 cells,the"HA coat"on the surface of MCF7/FulR cells was significantly thickened.IHC demonstrated markedly increased HA retention in fulvestrant-resistant mouse breast cancer tissues.ScRNA-seq and RNA-seq analyses indicated elevated expression of stemness-related genes and HA synthesis-associated genes in fulvestrant-resistant breast cancer cells.Correlation analysis revealed a positive association between HA synthesis and cancer stemness in ER+breast cancer.IF and RT-qPCR results demonstrated that removing the HA coating from the surface of MCF7/FulR cells led to a significant reduction in the expression of stemness-related molecules;concurrently,CCK-8 assays,FCM analysis,and Hoechst 33258 staining revealed that"HA coat"clearance reduced MCF7/FulR'tolerance to fulvestrant and increased apoptosis.Conclusion·Endocrine-resistant breast cancer cells develop an enriched"HA coat",which promotes stemness in fulvestrant-resistant tumors.Disruption of this HA coat through HAase treatment effectively reduces cell stemness,induces apoptosis,and re-sensitizes breast cancer cells to fulvestrant.

Objective:To analyze the epidemiological and clinical characteristics of pertussis cases identified through active surveillance.Methods:Active surveillance for pertussis was conducted in three sentinel hospitals in Yiwu, Zhejiang Province, and Yongcheng, Henan Province. The study population included cases that met the surveillance case definition and sought medical care at outpatient/emergency departments or were hospitalized between June 1, 2021, and May 31, 2022. Samples were collected for bacterial culture and PCR detection. Case information and clinical data were collected. Differences in rates were assessed using the chi-square test or Fisher's exact probability test, and the differences in cough time were compared using the Mann-Whitney U test. Results:Among 1 423 cases of pertussis surveillance, the positive rate of pertussis was 28.11% (400/1 423), with a median age of 5 years (interquartile range: 2, 8). The positive rate in Yongcheng, Henan Province, and Yiwu, Zhejiang Province were 39.27% (216/550) and 21.08% (184/873), respectively; the positive rate of pertussis was highest in July 2021, and the highest positive rate of pertussis was among those aged 10-14. The positive rate of pertussis in hospitalized cases was higher than in outpatient/emergency cases (26.68%) ( χ2=4.16, P=0.041). Among the 400 laboratory test-positive cases, the highest proportion of atypical symptom cases was in adults aged 20-59 (43.33%, 13/30). The specificity rates of apnea and worsening nocturnal cough in monitored cases under 3 months of age were 100.00% and 73.81%, respectively. Among monitored cases aged 3 months to 9 years, the proportions of symptoms including worsening nighttime cough (63.00%) and night sweats (4.59%) in test-positive cases were significantly higher than those in the test-negative group (47.77% and 0.56%, respectively), with statistically significant differences (both P<0.05). The specificity rates of worsened nighttime coughing and night sweats were 52.23% and 99.44%, respectively. Conclusions:The active surveillance results for pertussis showed that the 10-14 age group exhibited the highest positivity rate. Active surveillance enhanced the detection rate of pertussis. Among laboratory-confirmed cases, the proportion of atypical symptoms was the highest in adults, suggesting that laboratory testing should be combined to diagnose programs of pertussis. For infants under 3 months, worsening nighttime cough and apnea increase the diagnostic specificity, while for individuals aged 3 to 9 years old, worsening nighttime cough and night sweats increase the diagnostic specificity.

Objective: To explore the potential application of PAK4-PROTAC targeted degradation drug (PpD) in renal cancer immunotherapy. Methods: TIMER 2.0 and TISIDB databases were used to analyze the relationship among PAK4 expression, tumor purity and abundance of immune cell infiltration in renal tumor microenvironment (TEM).Renal cancer cell lines OS-RC-2, 786-O and ACHN were treated with 0, 125 and 250 nmol/L PpD, and the effects of Jurkat cell co-culture on the results were investigated.The cell apoptosis was detected with flow cytometry, and the expression of programmed cell death 1 ligand 1 (PD-L1) in renal cancer cells was detected with immunoblotting. Results: The high expression of PAK4 was positively related to immune purity, and inhibited the abundance of immune killer cells in TEM, such as CD8 T cells, CD4 T cells, natural killer cells and dendritic cells.With 250 nmol/L PpD treatment, there were 21.02% apoptotic cells in OS-RC-2, 29.67% apoptotic cells in 786-O, and 15.39% apoptotic cells in ACHN, respectively.However, with the same concentration of 250 nmol/L PpD treatment, cell apoptotic rate was sharply increased to 70.13% in OS-RC-2/Jurkat, 70.68% in 780-O/Jurkat, and 60.27% in ACHN/Jurkat co-culture models, respectively. Conclusion: PpD can promote apoptosis of renal cancer cells by reducing the expression of PAK4 protein, and enhance the killing effects of immune cells on tumor cells.

Objective·To determine hyaluronan(HA)expression in the endocrine-resistant microenvironment of estrogen receptor-positive(ER+)breast cancer and elucidate its impact on the acquired resistance.Methods·Chemiluminescent immunoassay was used to quantify HA levels in the culture supernatants of fulvestrant-resistant breast cancer cells.An immunofluorescence(IF)assay was performed to visualize the colocalization of CD44 and HA in MCF7/FulR cells.Using an established adaptive endocrine-resistant breast cancer mouse model,HA expression in resistant breast cancer tissues was assessed by immunohistochemistry(IHC)assay.Single-cell RNA sequencing(scRNA-seq)and RNA sequencing(RNA-seq)were conducted to examine transcriptomic profiles and alterations in HA-related genes in resistant breast cancer cells.Flow cytometry(FCM)was utilized to measure the proportion of CD44+CD24-cells in MCF7/FulR.The correlation between HA synthesis genes and cell stemness was investigated in clinical ER+breast cancers from GEO data sets.Hyaluronidase(HAase)treatment was applied to remove the"HA coat",and RT-qPCR and Western blotting analysis were carried out to monitor changes in stemness-related molecules.CCK-8 assays,flow cytometry(FCM),and Hoechst 33258 staining were performed to determine changes in apoptosis and fulvestrant efficiency after HAase treatment.Results·IF results revealed that compared with MCF7 cells,the"HA coat"on the surface of MCF7/FulR cells was significantly thickened.IHC demonstrated markedly increased HA retention in fulvestrant-resistant mouse breast cancer tissues.ScRNA-seq and RNA-seq analyses indicated elevated expression of stemness-related genes and HA synthesis-associated genes in fulvestrant-resistant breast cancer cells.Correlation analysis revealed a positive association between HA synthesis and cancer stemness in ER+breast cancer.IF and RT-qPCR results demonstrated that removing the HA coating from the surface of MCF7/FulR cells led to a significant reduction in the expression of stemness-related molecules;concurrently,CCK-8 assays,FCM analysis,and Hoechst 33258 staining revealed that"HA coat"clearance reduced MCF7/FulR'tolerance to fulvestrant and increased apoptosis.Conclusion·Endocrine-resistant breast cancer cells develop an enriched"HA coat",which promotes stemness in fulvestrant-resistant tumors.Disruption of this HA coat through HAase treatment effectively reduces cell stemness,induces apoptosis,and re-sensitizes breast cancer cells to fulvestrant.

Objective:To investigate the molecular mechanisms by which HMGB1 in lung cancer cells affects the function of lung cancer cells themselves and immune cells through the NF-κB pathway.Methods:Western blot detected HMGB1 expressions in Lewis lung cancer(LLC)cells,Raw264.7 cells,and mouse spleen cells,while tumor cell lysates(TCL)with low HMGB1 was pre-pared by inhibiting HMGB1 expression in lung cancer cells with glycyrrhetinic acid(GA);the effects of endogenous HMGB1 inhibi-tion or TCL with low HMGB1 on apoptosis and proliferation of lung cancer cells were detected by flow cytometry and CCK-8;TCL with normal HMGB1 or TCL with low HMGB1 was prepared by freeze-thawing;Raw264.7 cells and mouse splenocytes were treated with them for 48 h.Apoptosis and CD69 expression were detected by flow cytometry,and secretion of cytokines IL-2,IL-4,IL-6,TNF-α and TNF-β were detected by ELISA;Western blot detected lung cancer cells or immune cells.Western blot was performed to detect the protein expression of key signaling molecules of the NF-κB signaling pathway in lung cancer cells or immune cells.Results:HMGB1 was expressed in LLC cells,Raw264.7 cells,and mouse spleen cells,among which LLC cells had the highest expression of HMGB1,and 30 μg/ml GA had the best inhibitory effect on HMGB1 expression in LLC cells.Endogenous HMGB1 in LLC cells could promote cell proliferation.Exogenous HMGB1 in TCL induced apoptosis in lung cancer cells and inhibited immune cell activation and prolifera-tion.Inhibition of endogenous HMGB1 in lung cancer cells leaded to activation of the apoptosis-inducing factor CASP9 in the NF-κB signaling pathway,which was inhibited in lung cancer cells or immune cells after the action of TCL with low HMGB1.Conclusion:Tumor cell HMGB1 has a dual role in lung carcinogenesis,promoting the proliferation of lung cancer cells while suppressing the func-tion of immune cells,which in turn causes lung carcinogenesis,a process associated with the activation of the NF-κB signaling path-way in different cells.

Objective:To investigate the molecular mechanisms by which HMGB1 in lung cancer cells affects the function of lung cancer cells themselves and immune cells through the NF-κB pathway.Methods:Western blot detected HMGB1 expressions in Lewis lung cancer(LLC)cells,Raw264.7 cells,and mouse spleen cells,while tumor cell lysates(TCL)with low HMGB1 was pre-pared by inhibiting HMGB1 expression in lung cancer cells with glycyrrhetinic acid(GA);the effects of endogenous HMGB1 inhibi-tion or TCL with low HMGB1 on apoptosis and proliferation of lung cancer cells were detected by flow cytometry and CCK-8;TCL with normal HMGB1 or TCL with low HMGB1 was prepared by freeze-thawing;Raw264.7 cells and mouse splenocytes were treated with them for 48 h.Apoptosis and CD69 expression were detected by flow cytometry,and secretion of cytokines IL-2,IL-4,IL-6,TNF-α and TNF-β were detected by ELISA;Western blot detected lung cancer cells or immune cells.Western blot was performed to detect the protein expression of key signaling molecules of the NF-κB signaling pathway in lung cancer cells or immune cells.Results:HMGB1 was expressed in LLC cells,Raw264.7 cells,and mouse spleen cells,among which LLC cells had the highest expression of HMGB1,and 30 μg/ml GA had the best inhibitory effect on HMGB1 expression in LLC cells.Endogenous HMGB1 in LLC cells could promote cell proliferation.Exogenous HMGB1 in TCL induced apoptosis in lung cancer cells and inhibited immune cell activation and prolifera-tion.Inhibition of endogenous HMGB1 in lung cancer cells leaded to activation of the apoptosis-inducing factor CASP9 in the NF-κB signaling pathway,which was inhibited in lung cancer cells or immune cells after the action of TCL with low HMGB1.Conclusion:Tumor cell HMGB1 has a dual role in lung carcinogenesis,promoting the proliferation of lung cancer cells while suppressing the func-tion of immune cells,which in turn causes lung carcinogenesis,a process associated with the activation of the NF-κB signaling path-way in different cells.

Objective:To analyze the epidemiological and clinical characteristics of pertussis cases identified through active surveillance.Methods:Active surveillance for pertussis was conducted in three sentinel hospitals in Yiwu, Zhejiang Province, and Yongcheng, Henan Province. The study population included cases that met the surveillance case definition and sought medical care at outpatient/emergency departments or were hospitalized between June 1, 2021, and May 31, 2022. Samples were collected for bacterial culture and PCR detection. Case information and clinical data were collected. Differences in rates were assessed using the chi-square test or Fisher's exact probability test, and the differences in cough time were compared using the Mann-Whitney U test. Results:Among 1 423 cases of pertussis surveillance, the positive rate of pertussis was 28.11% (400/1 423), with a median age of 5 years (interquartile range: 2, 8). The positive rate in Yongcheng, Henan Province, and Yiwu, Zhejiang Province were 39.27% (216/550) and 21.08% (184/873), respectively; the positive rate of pertussis was highest in July 2021, and the highest positive rate of pertussis was among those aged 10-14. The positive rate of pertussis in hospitalized cases was higher than in outpatient/emergency cases (26.68%) ( χ2=4.16, P=0.041). Among the 400 laboratory test-positive cases, the highest proportion of atypical symptom cases was in adults aged 20-59 (43.33%, 13/30). The specificity rates of apnea and worsening nocturnal cough in monitored cases under 3 months of age were 100.00% and 73.81%, respectively. Among monitored cases aged 3 months to 9 years, the proportions of symptoms including worsening nighttime cough (63.00%) and night sweats (4.59%) in test-positive cases were significantly higher than those in the test-negative group (47.77% and 0.56%, respectively), with statistically significant differences (both P<0.05). The specificity rates of worsened nighttime coughing and night sweats were 52.23% and 99.44%, respectively. Conclusions:The active surveillance results for pertussis showed that the 10-14 age group exhibited the highest positivity rate. Active surveillance enhanced the detection rate of pertussis. Among laboratory-confirmed cases, the proportion of atypical symptoms was the highest in adults, suggesting that laboratory testing should be combined to diagnose programs of pertussis. For infants under 3 months, worsening nighttime cough and apnea increase the diagnostic specificity, while for individuals aged 3 to 9 years old, worsening nighttime cough and night sweats increase the diagnostic specificity.