1.A preliminary study on Toxoplasma gondii interfering with copper metabolism pathways in mouse kidney
Jun YANG ; Chuanming REN ; Min LIU ; Kunting WANG ; He CHEN ; Yihong CAI
Acta Universitatis Medicinalis Anhui 2026;61(1):127-132
ObjectiveTo investigate the effect of Toxoplasma gondii infection on copper metabolism in the kidneys of mice. MethodsA total of 80 7-8-week-old C57BL/6 female mice were randomly divided into four groups of 20 mice in each group after one week of adaptation, including Control group, Cu group, TgCtwh6 group and Cu+TgCtwh6 group. Mice that were not infected and fed with normal diet and water were used as the Control group; Mice fed with 1 g/kg of copper chloride processing diet and 0.1% copper chloride water for 60 consecutive days were used as Cu group; Mice infected with 25-30 TgCtwh6 cysts (one of the predominant genotype Chinese 1 in China) fed with normal diet and water were used as the TgCtwh6 group; mice infected with 25-30 TgCtwh6 cysts and fed with a processed diet containing 1 g/kg of copper chloride and water with 0.1% copper chloride for 60 consecutive days were used as the Cu+TgCtwh6 group. ICP-MS was used to determine the changes in copper content in kidney tissues. Hematoxylin-eosin (HE) staining was used to observe the pathological changes of mouse kidney tissue. The number of apoptotic cells was observed by PI staining. Western blot was used to detect the protein expression levels of glutathione peroxidase 4 (GPX4) and superoxide dismutase (SOD1, SOD2). RT-qPCR was used to detect the mRNA expression of cuproptosis-related genes. ResultsPathological manifestations such as inflammatory cell infiltration in the Cu group and TgCtwh6 group were seen under the microscope, and the inflammatory infiltrating cells of the renal interstitial were reduced in the Cu+TgCtwh6 group, and the pathological manifestations
2.Management of an imported family cluster of dengue fever cases in Shanghai, 2024
Lei SHEN ; Dongsheng REN ; Mingyi CAI ; Zhixiang TENG ; Qi SHEN ; Qingyuan XU ; Xiaofen NI
Shanghai Journal of Preventive Medicine 2026;38(2):170-174
ObjectiveTo investigate and manage an imported dengue fever (DF) outbreak in Shanghai in 2024, to summarize the experience and lessons learned from the on-site management, and to provide a reference basis for future prevention and control of DF. MethodsEpidemiological investigation and case search were carried out for an imported DF outbreak in Shanghai, 2024. Real-time fluorescence polymerase chain reaction (RT-PCR) was used to detect dengue virus nucleic acid in the serum samples from cases. Meanwhile, emergency vector surveillance and mosquito control measures were carried out in the affected areas, and the effectiveness of the management was evaluated. ResultsAccording to the epidemiological investigation, it was confirmed that this epidemic was a family cluster of imported DF, with both cases infected in Thailand and developed symptoms successively after returning to Shanghai. Laboratory testing identified the pathogens as dengue virus serotype-3 (DENV-3). In the core and precautionary area, ultra-low-volume space spraying and residual spraying were combined to kill adult mosquitoes, and at the same time, comprehensive cleaning and elimination of mosquito breeding sites was carried out. After 2 weeks, the Breteau Index (BI) in the core area decreased from 20 to 5, and the mosquito net trap index decreased from 2 mosquitoes (net·hour)-1 to 0.67 mosquitoes (net·hour)-1. Continuous implementation of mosquito control measures kept the BI and net trap index below the safety thresholds [BI<5 and mosquito net trap index <2 mosquitoes (net·hour)-1] both in the core and precautionary area. ConclusionEarly diagnosis and isolation of patients, combined with rapid suppression of the density of vector Aedes mosquitoes, are the key measures to prevent the transmission of imported DF cases.
3.Mechanisms of Xiaozhi Qinggan Decoction in Treatment of Metabolic Dysfunction-associated Steatotic Liver Disease by Regulating Ferroptosis
Haihang DONG ; Yuying TU ; Xingrong LI ; Yujie CAI ; Yi REN ; Huiqin ZHANG ; Yinqiang ZHANG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(6):109-119
ObjectiveTo investigate the mechanism of Xiaozhi Qinggan decoction (XQD) in preventing and treating metabolic dysfunction-associated steatotic liver disease (MASLD) by regulating ferroptosis, network pharmacology, in vitro and in vivo experiments. MethodsIn the in vivo experiment, mouse MASLD models were established by high-fat diet (HFD) induction. The model mice were randomly assigned to a positive control group (silybin, 50 mg·kg-1), low-, medium- and high-dose XQD groups (4.725, 9.45, 18.9 g·kg-1), with a normal control group. After 4 weeks of modeling, mice except the normal group were administered intragastrically for 8 consecutive weeks. Liver function, serum lipid levels, hepatic histopathology, as well as the levels of malondialdehyde (MDA), superoxide dismutase (SOD), reduced glutathione (GSH) and oxidized glutathione (GSSG) and Fe2+ were detected. The mRNA and protein expression of p53, SLC7A11 and GPX4 were determined by quantitative Real-time quantitative polymerase chain reaction(Real-time PCR) and Western blot. In the network pharmacology analysis, active components and potential targets of XQD for MASLD were screened, followed by functional and pathway enrichment analyses, and molecular docking was performed to verify the target binding activity. In the in vitro experiment, the optimal concentration of XQD-containing serum was screened by cytotoxicity assay. HepG2 cells were transfected with ov-NC or ov-p53 plasmid, and a lipid accumulation model was induced by free fatty acid (FFA, 1.0 mmol·L-1). Cells were divided into a normal group, FFA model group, ov-NC+XQD (15%) group and ov-p53+XQD (15%) group. Intracellular Fe2+ level and lipid accumulation were evaluated, and the protein expression of p53, SLC7A11 and GPX4 was measured by Western blot. ResultsCompared with the normal group, the model group exhibited markedly elevated body weight, liver weight, liver index, fasting blood glucose, AUC of glucose tolerance test, serum liver function and blood lipid levels at week 12 (P<0.01). Hepatic steatosis and inflammatory infiltration were observed by pathological staining. Additionally, hepatic levels of MDA, SOD and Fe2+ were increased (P<0.01), while GSH, GSSG and the GSH/GSSG ratio were decreased (P<0.01). The mRNA and protein expression of hepatic p53 was upregulated (P<0.01), whereas the expression of SLC7A11 and GPX4 was downregulated (P<0.01). Compared with the model group, the low- and medium-dose XQD groups showed significantly decreased body weight at week 12 (P<0.05). The silybin group, together with the medium- and high-dose XQD groups, presented reduced liver weight and liver index (P<0.05). Fasting blood glucose and the AUC of glucose tolerance test were lowered in all four treatment groups (P<0.05, P<0.01). Pathological staining revealed alleviated hepatic steatosis and inflammation, accompanied by decreased serum liver function and blood lipid levels (P<0.05, P<0.01). Moreover, hepatic MDA and SOD levels were markedly reduced, while GSH, GSSG and the GSH/GSSG ratio were significantly elevated (P<0.05, P<0.01). Hepatic Fe2+ level was decreased (P<0.01). The mRNA and protein expression of hepatic p53 was downregulated, and the expression of SLC7A11 and GPX4 was upregulated (P<0.05, P<0.01). Network pharmacology analysis identified quercetin, kaempferol, luteolin, tanshinone IIA and isorhamnetin as the core active components of XQD, with p53 serving as the key target. Stable binding was verified between these active components and the p53 protein. The optimal concentration of XQD-containing serum in vitro was determined to be 15%. Compared with the normal group, the model group showed increased intracellular Fe2+ and lipid accumulation, significantly upregulated p53 protein expression (P<0.01), and markedly downregulated SLC7A11 and GPX4 protein expression (P<0.01). Compared with the model group, the ov-NC group exhibited reduced Fe2+ and lipid accumulation, downregulated p53 expression, and upregulated SLC7A11 and GPX4 expression. In the ov-p53 group, p53 expression was upregulated (P<0.01), while SLC7A11 and GPX4 expression was downregulated (P<0.01). ConclusionXQD inhibits ferroptosis by downregulating p53 and upregulating SLC7A11 and GPX4, thereby alleviating oxidative stress and lipid peroxidation in hepatocytes and improving MASLD.
4.Polypeptide-based Nanocarriers for Oral Targeted Delivery of CAR Genes to Pancreatic Cancer
Feng XIN ; Jian REN ; Zhao-Zhen LI ; Quan FANG ; Rui-Jing LIANG ; Lan-Lan LIU ; Lin-Tao CAI
Progress in Biochemistry and Biophysics 2026;53(2):431-441
ObjectivePancreatic ductal adenocarcinoma (PDAC) exhibits a limited response to current treatments due to its dense fibrotic stroma and highly immunosuppressive tumor microenvironment. In recent years, advancements in cellular immunotherapy, particularly chimeric antigen receptor macrophage (CAR-M) therapy, have offered new hope for pancreatic cancer treatment. Although CAR-M therapy demonstrates dual potential in directly killing tumor cells and remodeling the immune microenvironment, it still faces challenges such as complex in vitro preparation processes and low in vivo targeting and delivery efficiency. Therefore, developing strategies for efficient and targeted in vivo delivery of CAR genes has become crucial for overcoming current therapeutic limitations. This study aims to develop an orally administrable nano-gene delivery system for the targeted delivery of CAR genes to pancreatic tumor sites. MethodsCore nano-gene particles (PNP/pCAR) were constructed by loading plasmid DNA encoding CAR (pCAR) with cationic polypeptides (PNP). Subsequently, PNP/pCAR was surface-modified with β-glucan to prepare the targeted nanoparticles (βGlus-PNP/pCAR). The loading efficiency of PNP for pCAR was quantitatively assessed by gel retardation assay. The particle size, Zeta potential, morphology, and storage stability of PNP/pCAR were characterized using a Malvern particle size analyzer and transmission electron microscopy. At the cellular level, RAW 264.7 macrophages were selected. The cytotoxicity of PNP/pCAR was evaluated using the CCK-8 assay. The cellular uptake efficiency and lysosomal escape ability of the nanoparticles were assessed via flow cytometry and confocal microscopy. Transfection efficiency was quantitatively evaluated by detecting the expression of the reporter gene GFP using flow cytometry. At the in vivo level, an orthotopic pancreatic cancer mouse model was established. Cy7-labeled βGlus-PNP/pCAR nanoparticles were administered orally, and the fluorescence distribution in mice was dynamically monitored at 1, 2, 4, 8, and 16 h post-administration using a small animal in vivo imaging system. Forty-eight hours after oral gavage, the mice were euthanized, and pancreatic tumor tissues were collected for further analysis of intratumoral fluorescence signals using the imaging system. Additionally, βGlus-PNP/pCAR-GFP nanoparticles loaded with the reporter gene (GFP) were administered orally. Forty-eight hours post-administration, pancreatic tumor tissues were harvested to prepare frozen sections, and GFP expression was observed and analyzed under a fluorescence microscope. ResultsThe PNP carrier exhibited a high loading capacity for pCAR. The successfully prepared PNP/pCAR nanoparticles were regular spheres with a hydrodynamic diameter of approximately (120±10) nm and a Zeta potential of about +(6±1) mV. They maintained good structural stability after incubation in PBS buffer for 7 d. Cell experiments demonstrated that PNP/pCAR exhibited no significant cytotoxicity in RAW 264.7 cells while being efficiently internalized and effectively escaping lysosomal degradation. The transfection positive rate of PNP/pCAR-GFP in RAW 264.7 cells reached (25±3)%, surpassing that of Lipofectamine 2000-loaded pCAR-GFP (Lipo/pCAR-GFP), which was (20±1)%.In vivo experiments revealed that, compared to unmodified PNP/pCAR, βGlus-PNP/pCAR exhibited strongerin situ pancreatic tumor targeting ability after oral administration. Furthermore, oral administration of βGlus-PNP/pCAR-GFP resulted in significant GFP protein expression detectable within pancreatic tumor tissues. ConclusionThis study successfully constructed and validated an orally administrable, pancreatic cancer-targeting polypeptide-based nano-gene delivery system. It provides an important technological foundation in delivery systems and experimental basis for the subsequent development of in situ CAR-M-based therapeutic strategies for pancreatic cancer.
5.Polypeptide-based Nanocarriers for Oral Targeted Delivery of CAR Genes to Pancreatic Cancer
Feng XIN ; Jian REN ; Zhao-Zhen LI ; Quan FANG ; Rui-Jing LIANG ; Lan-Lan LIU ; Lin-Tao CAI
Progress in Biochemistry and Biophysics 2026;53(2):431-441
ObjectivePancreatic ductal adenocarcinoma (PDAC) exhibits a limited response to current treatments due to its dense fibrotic stroma and highly immunosuppressive tumor microenvironment. In recent years, advancements in cellular immunotherapy, particularly chimeric antigen receptor macrophage (CAR-M) therapy, have offered new hope for pancreatic cancer treatment. Although CAR-M therapy demonstrates dual potential in directly killing tumor cells and remodeling the immune microenvironment, it still faces challenges such as complex in vitro preparation processes and low in vivo targeting and delivery efficiency. Therefore, developing strategies for efficient and targeted in vivo delivery of CAR genes has become crucial for overcoming current therapeutic limitations. This study aims to develop an orally administrable nano-gene delivery system for the targeted delivery of CAR genes to pancreatic tumor sites. MethodsCore nano-gene particles (PNP/pCAR) were constructed by loading plasmid DNA encoding CAR (pCAR) with cationic polypeptides (PNP). Subsequently, PNP/pCAR was surface-modified with β-glucan to prepare the targeted nanoparticles (βGlus-PNP/pCAR). The loading efficiency of PNP for pCAR was quantitatively assessed by gel retardation assay. The particle size, Zeta potential, morphology, and storage stability of PNP/pCAR were characterized using a Malvern particle size analyzer and transmission electron microscopy. At the cellular level, RAW 264.7 macrophages were selected. The cytotoxicity of PNP/pCAR was evaluated using the CCK-8 assay. The cellular uptake efficiency and lysosomal escape ability of the nanoparticles were assessed via flow cytometry and confocal microscopy. Transfection efficiency was quantitatively evaluated by detecting the expression of the reporter gene GFP using flow cytometry. At the in vivo level, an orthotopic pancreatic cancer mouse model was established. Cy7-labeled βGlus-PNP/pCAR nanoparticles were administered orally, and the fluorescence distribution in mice was dynamically monitored at 1, 2, 4, 8, and 16 h post-administration using a small animal in vivo imaging system. Forty-eight hours after oral gavage, the mice were euthanized, and pancreatic tumor tissues were collected for further analysis of intratumoral fluorescence signals using the imaging system. Additionally, βGlus-PNP/pCAR-GFP nanoparticles loaded with the reporter gene (GFP) were administered orally. Forty-eight hours post-administration, pancreatic tumor tissues were harvested to prepare frozen sections, and GFP expression was observed and analyzed under a fluorescence microscope. ResultsThe PNP carrier exhibited a high loading capacity for pCAR. The successfully prepared PNP/pCAR nanoparticles were regular spheres with a hydrodynamic diameter of approximately (120±10) nm and a Zeta potential of about +(6±1) mV. They maintained good structural stability after incubation in PBS buffer for 7 d. Cell experiments demonstrated that PNP/pCAR exhibited no significant cytotoxicity in RAW 264.7 cells while being efficiently internalized and effectively escaping lysosomal degradation. The transfection positive rate of PNP/pCAR-GFP in RAW 264.7 cells reached (25±3)%, surpassing that of Lipofectamine 2000-loaded pCAR-GFP (Lipo/pCAR-GFP), which was (20±1)%.In vivo experiments revealed that, compared to unmodified PNP/pCAR, βGlus-PNP/pCAR exhibited strongerin situ pancreatic tumor targeting ability after oral administration. Furthermore, oral administration of βGlus-PNP/pCAR-GFP resulted in significant GFP protein expression detectable within pancreatic tumor tissues. ConclusionThis study successfully constructed and validated an orally administrable, pancreatic cancer-targeting polypeptide-based nano-gene delivery system. It provides an important technological foundation in delivery systems and experimental basis for the subsequent development of in situ CAR-M-based therapeutic strategies for pancreatic cancer.
6.Dynamic Sequential Diagnosis and Treatment of Pediatric Nephrotic Syndrome Based on the "Sweat Pore-Qi and Liquid-Kidney Collaterals"
Zhenhua YUAN ; Mingyang CAI ; Yingying JIANG ; Jingjing WU ; Wenqing PAN ; Zichao DING ; Shuzi ZHANG ; Xianqing REN
Journal of Traditional Chinese Medicine 2025;66(10):1007-1010
Based on the viewpoint of "sweat pore-qi and liquid-kidney collaterals", it is believed that children's nephrotic syndrome is caused by the core mechanism of sweat pore constraint and closure, qi and liquid imbalance, and kidney collaterals impairment, and it is proposed that the treatment principle is to nourish the sweat pore, regulate qi and fluid, and supplement the kidney and unblock the collaterals. In clinic, guided by sequential therapy and according to the different disease mechanism characteristics of the four stages, including early stage of the disease, hormone induction stage, hormone reduction stage, hormone maintenance stage, the staged dynamic identification and treatment was applied. For early stage of the disease with edema due to yang deficiency, modified Zhenwu Decoction (真武汤) was applied to warm yang and drain water; for hormone induction stage with yin deficiency resulting in effulgent fire, modified Zhibai Dihuang Pill (知柏地黄丸) plus Erzhi Pill (二至丸) was used to enrich yin and reduce fire; for hormone reduction stage with qi and yin deficiency, modified Shenqi Dihuang Decoction (参芪地黄汤) was used to boost qi and nourish yin; for hormone maintenance stage, modified Shenqi Pill (肾气丸) was used to supplement yin and yang. Meanwhile, the treatment also attaches importance to the combination of vine-based or worm medicinals to dredge collaterals, so as to providing ideas for clinical treatment.
7.Quality evaluation of Xinjiang Rehmannia glutinosa and Rehmannia glutinosa based on fingerprint and multi-component quantification combined with chemical pattern recognition.
Pan-Ying REN ; Wei ZHANG ; Xue LIU ; Juan ZHANG ; Cheng-Fu SU ; Hai-Yan GONG ; Chun-Jing YANG ; Jing-Wei LEI ; Su-Qing ZHI ; Cai-Xia XIE
China Journal of Chinese Materia Medica 2025;50(16):4630-4640
The differences in chemical quality characteristics between Xinjiang Rehmannia glutinosa and R. glutinosa were analyzed to provide a theoretical basis for the introduction and quality control of R. glutinosa. In this study, the high performance liquid chromatography(HPLC) fingerprints of 6 batches of Xinjiang R. glutinosa and 10 batches of R. glutinosa samples were established. The content of iridoid glycosides, phenylethanoid glycosides, monosaccharides, oligosaccharides, and polysaccharides in Xinjiang R. glutinosa and R. glutinosa was determined by high performance liquid chromatography-diode array detection(HPLC-DAD), high performance liquid chromatography-evaporative light scattering detection(HPLC-ELSD), and ultraviolet-visible spectroscopy(UV-Vis). The determination results were analyzed with by chemical pattern recognition and entropy weight TOPSIS method. The results showed that there were 19 common peaks in the HPLC fingerprints of the 16 batches of R. glutinosa, and catalpol, aucubin, rehmannioside D, rehmannioside A, hydroxytyrosol, leonuride, salidroside, cistanoside A, and verbascoside were identified. Hierarchical cluster analysis(HCA) and principal component analysis(PCA) showed that Qinyang R. glutinosa, Mengzhou R. glutinosa, and Xinjiang R. glutinosa were grouped into three different categories, and eight common components causing the chemical quality difference between Xinjiang R. glutinosa and R. glutinosa in Mengzhou and Qinyang of Henan province were screened out by orthogonal partial least squares discriminant analysis(OPLS-DA). The results of content determination showed that there were glucose, sucrose, raffinose, stachyose, polysaccharides, and nine glycosides in Xinjiang R. glutinosa and R. glutinosa samples, and the content of catalpol, rehmannioside A, leonuride, cistanoside A, verbascoside, sucrose, and glucose was significantly different between Xinjiang R. glutinosa and R. glutinosa. The analysis with entropy weight TOPSIS method showed that the comprehensive quality of R. glutinosa in Mengzhou and Qinyang of Henan province was better than that of Xinjiang R. glutinosa. In conclusion, the types of main chemical components of R. glutinosa and Xinjiang R. glutinosa were the same, but their content was different. The chemical quality of R. glutinosa was better than Xinjiang R. glutinosa, and other components in R. glutinosa from two producing areas and their effects need further study.
Rehmannia/classification*
;
Drugs, Chinese Herbal/chemistry*
;
Chromatography, High Pressure Liquid/methods*
;
Quality Control
8.Retrospective analysis of application value of percutaneous plate internal fixation after external fixation stenting in patients with open fracture of tibial shaft.
Peng-Fei CAI ; Wei ZHAO ; Jin-Hua WANG ; Ren-Sheng CHEN ; Xiao-Fei LI
China Journal of Orthopaedics and Traumatology 2025;38(3):273-279
OBJECTIVE:
To compare clinical effects of external fixation and minimally invasive percutaneous plate osteosynthesis (MIPPO) after external fixation in treating open fractures of tibial shaft.
METHODS:
From January 2020 to June 2022, 151 patients with open fracture of tibial shaft treated with external fixation stenting were divided into external fixation group and combined group according to different surgical methods. There were 81 patients in external fixation group, including 48 males and 33 females, aged from 21 to 68 years old with an average of (42.58±7.44) years old;according to Gustilo classification, 49 patients with typeⅡ, 32 patients with type ⅢA;the time from injury to treatment ranged from 2.5 to 10 h with an average of (4.25±0.74) h;external fixed stenting was performed. There were 70 patients in combined group, including 42 males and 28 females, aged from 20 to 69 years old with an average of (41.39±7.02) years old;35 patients with type Ⅱ and 35 patients with type ⅢA according to Gustilo classification;the time from injury to treatment ranged from 3 to 9 h with an average of (4.31±0.85) h;MIPPO treatment was performed after external fixed stenting. The time of callus formation, fracture healing and complications were compared between two groups. Rasmussen score and Hospital for Special Surgery (HSS) score were used to evaluate functional recovery of knee joint at 6 months after operation.
RESULTS:
Both groups were followed up for 6 to 13 months with an average of (10.17±2.33) months. The time of callus formation and fracture healing were (13.98±4.02) d and (70.26±12.15) d in combined group, and (18.56±4.37) d and (79.87±15.41) d in external fixation group, respectively. Combined group was better than external fixation group in the time of callus formation and fracture healing (P<0.05). At six months after operation, Rasmussen and HSS scores in combined group were (26.79±3.11) and (83.36±9.44), which were higher than those in external fixation group (24.51±4.63) and (79.63±8.46) (P<0.05). In external fixation group, there were 2 patients with incision infection, 2 patients with nail tract infection, 1 patient with stent loosening, fracture displacement, delayed union and malunion, and 1 patient with biocompatibility reaction in combined group, with statistical significance between two groups (P<0.05).
CONCLUSION
MIPPO could accelerate callus formation and fracture healing, improve knee function, improve clinical effects and reduce complications in patients with open tibial shaft fractures after external and external fixation.
Humans
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Male
;
Female
;
Middle Aged
;
Adult
;
Aged
;
Tibial Fractures/physiopathology*
;
Fracture Fixation, Internal/methods*
;
Retrospective Studies
;
Bone Plates
;
External Fixators
;
Fractures, Open/physiopathology*
;
Stents
;
Young Adult
9.O-GlcNAcylated YTHDF2 promotes bladder cancer progression by regulating the tumor suppressor gene PER1 via m6A modification.
Li WANG ; Da REN ; Zeqiang CAI ; Wentao HU ; Yuting CHEN ; Xuan ZHU
Journal of Central South University(Medical Sciences) 2025;50(5):827-839
OBJECTIVES:
Bladder cancer is a common malignancy with high incidence and poor prognosis. N6-methyladenosine (m6A) modification is widely involved in diverse physiological processes, among which the m6A recognition protein YTH N6-methyladenosine RNA binding protein F2 (YTHDF2) plays a crucial role in bladder cancer progression. This study aims to elucidate the molecular mechanism by which O-linked N-acetylglucosamine (O-GlcNAc) modification of YTHDF2 regulates its downstream target, period circadian regulator 1 (PER1), thereby promoting bladder cancer cell proliferation.
METHODS:
Expression of YTHDF2 in bladder cancer was predicted using The Cancer Genome Atlas (TCGA). Twenty paired bladder cancer and adjacent normal tissues were collected at the clinical level. Normal bladder epithelial cells (SV-HUC-1) and bladder cancer cell lines (T24, 5637, EJ-1, SW780, BIU-87) were examined by quantitative real-time PCR (RT-qPCR), Western blotting, and immunohistochemistry for expression of YTHDF2, PER1, and proliferation-related proteins [proliferating cell nuclear antigen (PCNA), minichromosome maintenance complex component 2 (MCM2), Cyclin D1]. YTHDF2 was silenced in 5637 and SW780 cells, and cell proliferation was assessed by Cell Counting Kit-8 (CCK-8), colony formation, and EdU assays. Bioinformatics was used to predict glycosylation sites of YTHDF2, and immunoprecipitation (IP) was performed to detect O-GlcNAc modification levels of YTHDF2 in tissues and cells. Bladder cancer cells were treated with DMSO, OSMI-1 (O-GlcNAc inhibitor), or Thiamet G (O-GlcNAc activator), followed by cycloheximide (CHX), to assess YTHDF2 ubiquitination by IP. YTHDF2 knockdown and Thiamet G treatment were further used to evaluate PER1 mRNA stability, PER1 m6A modification, and cell proliferation. TCGA was used to predict PER1 expression in tissues; SRAMP predicted potential PER1 m6A sites. Methylated RNA immunoprecipitation (MeRIP) assays measured PER1 m6A modification. Finally, the effects of knocking down YTHDF2 and PER1 on 5637 and SW780 cell proliferation were assessed.
RESULTS:
YTHDF2 expression was significantly upregulated in bladder cancer tissues compared with adjacent tissues (mRNA: 2.5-fold; protein: 2-fold), which O-GlcNAc modification levels increased 3.5-fold (P<0.001). YTHDF2 was upregulated in bladder cancer cell lines, and its knockdown suppressed cell viability (P<0.001), downregulated PCNA, MCM2, and CyclinD1 (all P<0.05), reduced colony numbers 3-fold (P<0.01), and inhibited proliferation. YTHDF2 exhibited elevated O-GlcNAc modification in cancer cells. OSMI-1 reduced YTHDF2 protein stability (P<0.01) and enhanced ubiquitination, while Thiamet G exerted opposite effects (P<0.001). Thiamet G reversed the proliferation-suppressive effects of YTHDF2 knockdown, promoting cell proliferation (P<0.01) and upregulating PCNA, MCM2, and CyclinD1 (all P<0.05). Mechanistically, YTHDF2 targeted PER1 via m6A recognition, promoting PER1 mRNA degradation. Rescue experiments showed that PER1 knockdown reversed the inhibitory effect of YTHDF2 knockdown on cell proliferation, upregulated PCNA, MCM2, and Cyclin D1 (all P<0.05), and promoted bladder cancer cell proliferation (P<0.001).
CONCLUSIONS
O-GlcNAc modification YTHDF2 promotes bladder cancer development by downregulating the tumor suppressor gene PER1 through m6A-mediated post-transcriptional regulation.
Humans
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Urinary Bladder Neoplasms/metabolism*
;
RNA-Binding Proteins/genetics*
;
Cell Proliferation
;
Cell Line, Tumor
;
Disease Progression
;
Acetylglucosamine/metabolism*
;
Adenosine/metabolism*
;
Gene Expression Regulation, Neoplastic
;
Genes, Tumor Suppressor

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