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 ; 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

OBJECTIVES: To investigate the expression of CDKN3 in gastric cancer and its impact on prognosis of gastric cancer patients. METHODS: We analyzed CDKN3 expression in clinical specimens from 114 gastric cancer patients and assessed its association with 5-year postoperative survival of the patients. GO and KEGG enrichment analyses were used to predict the biological function and possible mechanism of CDKN3. The effects of lentivirus-mediated CDKN3 knockdown on biological behaviors of gastric cancer cells were evaluated using Transwell assay, CCK-8 assay, TUNEL staining, flow cytometry, and Western blotting. RESULTS: CDKN3 expression was significantly higher in gastric cancer tissues than in the adjacent tissues with significant correlations with CEA level, CA19-9 level, and T and N staging (P<0.05). High CDKN3 expression was an independent risk factor affecting 5-year postoperative survival of the patients and predictive for long-term prognosis (P<0.01). Enrichment analyses suggested a probable association of CDKN3 with apoptosis. In MGC-803 cells, CDKN3 knockdown significantly lowered migration and invasion capacities of the cells, while CDKN3 overexpression produced the opposite effects. TUNEL staining revealed a significantly lower level of cell apoptosis in gastric cancer tissues than in adjacent tissues (P<0.01). CDKN3 knockdown obviously inhibited proliferation and increased apoptosis of MGC-803 cells. CDKN3 overexpression down-regulated the expressions of p53, p21 and Bax and up-regulated the expressions of p-p65 and Bcl-2. CONCLUSIONS CDKN3 is highly expressed in gastric cancer tissues and affects patient prognosis. CDKN3 overexpression promotes proliferation, invasion and migration and suppressed apoptosis of gastric cancer cells possibly through the p53/NF-κB signaling pathway.
Humans ; Stomach Neoplasms/pathology* ; Apoptosis ; Signal Transduction ; Tumor Suppressor Protein p53/metabolism* ; Cell Movement ; Cell Line, Tumor ; NF-kappa B/metabolism* ; Prognosis ; Cyclin-Dependent Kinase Inhibitor Proteins/metabolism* ; Cell Proliferation ; Neoplasm Invasiveness ; Male ; Female ; Dual-Specificity Phosphatases

Dysregulation of p53 and phosphoinositide (PIPn) signaling are both key drivers of oncogenesis and metastasis. Our recent findings reveal a previously unrecognized interaction between these pathways, converging in the nucleus to form a PIPn-p53 signalosome that modulates nuclear AKT activation and downstream signaling, thereby influencing cancer cell survival and motility. This review examines recent insights into nuclear PIPn signaling in the context of established roles for p53 in cell dynamics and migration while also deliberating current research on how nuclear PIPns interact with p53 to form signalosomes that affect cell motility. We emphasize the critical role of PIPns in stabilizing p53 and activating de novo nuclear AKT signaling, which subsequently modulates key motility-related pathways. Understanding the unique operation and function of the PIPn-p53 signalosome in nuclear phosphatidylinositol 3-kinase (PI3K)-AKT activation offers novel therapeutic strategies for controlling cancer metastasis by targeting pertinent interactions and events.
Humans ; Tumor Suppressor Protein p53/metabolism* ; Signal Transduction ; Cell Movement ; Cell Nucleus/metabolism* ; Phosphatidylinositols/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; Animals ; Neoplasms/pathology* ; Phosphatidylinositol 3-Kinases/metabolism*

OBJECTIVES: To investigate the effect of nuclear protein (Nupr) 1 on the pathological progression of osteoarthritis and its relationship with ferroptosis of chondrocytes. METHODS: Chondrocytes from mouse knees were divided into small interfering RNA (siRNA) control group, small interfering RNA targeting Nupr1 (siNupr1) group, siRNA control+IL-1β group (siRNA control interference for 24 h followed by 10 ng/mL IL-1β) and siNupr1+IL-1β group (siNupr1 interference for 24 h followed by 10 ng/mL IL-1β). The protein and mRNA expressions of Nupr1 were detected by Western blotting and quantitative reverse transcription polymerase chain reaction (qRT-PCR). Cell proliferation viabilities were measured using the cell counting kit-8 method. The levels of ferrous ions were detected by FerroOrange staining. Lipid peroxidation levels were detected by C11-BODIPY-591 fluorescence imaging. The contents of malondialdehyde (MDA) and glutathione (GSH) were detected by enzyme-linked immunosorbent assay. The protein expressions of acyl-CoA synthetase long-chain family (ACSL) 4, P53, glutathione peroxidase (GPX) 4 and solute carrier family 7 member 11 gene (SLC7A11) were detected by Western blotting. The osteoarthritis model was constructed by destabilization of the medial meniscus (DMM) surgery in 7-week-old male C57BL/6J mice. The mice were randomly divided into four groups with 10 animals in each group: sham surgery (Sham)+adeno-associated virus serotype 5 (AAV5)-short hairpin RNA (shRNA) control group, Sham+AAV5-shRNA control targeting Nupr1 (shNupr1) group, DMM+AAV5-shRNA control group, and DMM+AAV5-shNupr1 group. Hematoxylin and eosin staining and Safranin O-Fast Green staining were used to observe the morphological changes in cartilage tissue. The Osteoarthritis Research Society International (OARSI) osteoarthritis cartilage histopathology assessment system was used to evaluate the degree of cartilage degeneration in mice. The mRNA expressions of matrix metallopeptidase (MMP) 13, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) 5, cyclooxy-genase (COX) 2, and GPX4 were detected by qRT-PCR. RESULTS: In vitro experiments showed that knocking down Nupr1 alleviated the decrease of chondrocyte proliferation activity induced by IL-1β, reduced iron accumulation in mouse chondrocytes, lowered lipid peroxidation, downregulated ACSL4 and P53 protein expression and upregulated GPX4 and SLC7A11 protein expression (all P<0.01), thereby inhibiting ferroptosis in mouse chondrocytes. Meanwhile, in vivo animal experiments demonstrated that knocking down Nupr1 delayed the degeneration of articular cartilage in osteoarthritis mice, improved the OARSI score, slowed down the degradation of the extracellular matrix in osteoarthritis cartilage, and reduced the expression of the key ferroptosis regulator GPX4 (all P<0.01). CONCLUSIONS Knockdown of Nupr1 can delay the pathological progression of osteoarthritis through inhibiting ferroptosis in mouse chondrocytes.
Animals ; Ferroptosis ; Mice ; Chondrocytes/metabolism* ; Osteoarthritis/pathology* ; RNA, Small Interfering/genetics* ; Basic Helix-Loop-Helix Transcription Factors/genetics* ; Interleukin-1beta/metabolism* ; Phospholipid Hydroperoxide Glutathione Peroxidase/genetics* ; Coenzyme A Ligases/genetics* ; Tumor Suppressor Protein p53/metabolism* ; Mice, Inbred C57BL ; DNA-Binding Proteins ; Neoplasm Proteins ; Amino Acid Transport System y+ ; Nuclear Receptor Subfamily 1, Group D, Member 1

OBJECTIVE: To investigate the effects of LASS2/TMSG1 gene overexpression on proliferation and apoptosis of human lung cancer A549 cells and explore the possible mechanism. METHODS: We examined LASS2/TMSG1 expression level in a previously constructed A549 cell line overexpressing LASS2/TMSG1 using Western blotting. The proliferation and apoptosis of the cells were detected using colony-forming assay, CCK-8 assay, Hoechst/PI double staining and flow cytometry. Fourteen nude mice were randomized into 2 groups (n=7) to receive subcutaneous injection of A549 cells with or without LASS2/TMSG1 overexpression on the back of the neck, and the cell proliferation in vivo was observed. The expression levels of p38 MAPK protein and p-p38 MAPK protein in the xenografts were detected with Western blotting. ELISA was used to detect the levels of ceramide and p38 MAPK protein in cultured A549 cell supernatants and the xenografts in nude mice. RESULTS: Compared with the negative control cells, A549 cells with LASS2/TMSG1 overexpression had significantly lowered proliferation ability in vitro with increased early apoptosis rate (P < 0.05), and showed obvious growth inhibition after inoculation in nude mice(P < 0.05). Western blotting showed that in both cultured A549 cells and the xenografts in nude mice, LASS2/TMSG1 gene overexpression significantly increased the expression levels of p38 MAPK protein and p-p38 MAPK protein (P < 0.05); the results of ELISA also revealed significantly increased levels of ceramide and p38 MAPK protein in the cell supernatant andxenografts as well (P < 0.05). CONCLUSION Overexpression of LASS2/TMSG1 gene can significantly inhibit the proliferation and promote early apoptosis of human lung cancer A549 cells both in vitro and in vivo possibly by upregulating the expressions of ceramide and p38 MAPK protein to activate a signal transduction cascade.
Animals ; Humans ; Mice ; A549 Cells ; Apoptosis ; Cell Line, Tumor ; Cell Proliferation ; Lung Neoplasms ; Membrane Proteins/metabolism* ; Mice, Nude ; p38 Mitogen-Activated Protein Kinases/metabolism* ; Signal Transduction ; Tumor Suppressor Proteins/metabolism*

Gliomas are the most common central nervous system tumours; they are highly aggressive and have a poor prognosis. RGS16 belongs to the regulator of G-protein signalling (RGS) protein family, which plays an important role in promoting various cancers, such as breast cancer, pancreatic cancer, and colorectal cancer. Moreover, previous studies confirmed that let-7c-5p, a well-known microRNA, can act as a tumour suppressor to regulate the progression of various tumours by inhibiting the expression of its target genes. However, whether RGS16 can promote the progression of glioma and whether it is regulated by miR let-7c-5p are still unknown. Here, we confirmed that RGS16 is upregulated in glioma tissues and that high expression of RGS16 is associated with poor survival. Ectopic deletion of RGS16 significantly suppressed glioma cell proliferation and migration both in vitro and in vivo. Moreover, RGS16 was validated as a direct target gene of miR let-7c-5p. The overexpression of miR let-7c-5p obviously downregulated the expression of RGS16, and knocking down miR let-7c-5p had the opposite effect. Thus, we suggest that the suppression of RGS16 by miR let-7c-5p can promote glioma progression and may serve as a potential prognostic biomarker and therapeutic target in glioma.
Humans ; Phosphatidylinositol 3-Kinases/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; MicroRNAs/metabolism* ; Glioma/genetics* ; Genes, Tumor Suppressor ; Cell Proliferation ; Gene Expression Regulation, Neoplastic ; Cell Line, Tumor

Chromodomain-helicase-DNA-binding protein 1 (CHD1) deletion is among the most common mutations in prostate cancer (PCa), but its role remains unclear. In this study, RNA sequencing was conducted in PCa cells after clustered regularly interspaced palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9)-based CHD1 knockout. Gene set enrichment analysis (GSEA) indicated upregulation of hypoxia-related pathways. A subsequent study confirmed that CHD1 deletion significantly upregulated hypoxia-inducible factor 1α (HIF1α) expression. Mechanistic investigation revealed that CHD1 deletion upregulated HIF1α by transcriptionally downregulating prolyl hydroxylase domain protein 2 (PHD2), a prolyl hydroxylase catalyzing the hydroxylation of HIF1α and thus promoting its degradation by the E3 ligase von Hippel-Lindau tumor suppressor (VHL). Functional analysis showed that CHD1 deletion promoted angiogenesis and glycolysis, possibly through HIF1α target genes. Taken together, these findings indicate that CHD1 deletion enhances HIF1α expression through PHD2 downregulation and therefore promotes angiogenesis and metabolic reprogramming in PCa.
Male ; Humans ; Von Hippel-Lindau Tumor Suppressor Protein/metabolism* ; DNA-Binding Proteins/metabolism* ; Prolyl Hydroxylases/metabolism* ; Hypoxia ; Prostatic Neoplasms/pathology* ; Glycolysis ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Cell Line, Tumor ; DNA Helicases/metabolism*

Lung squamous cell carcinoma (LSCC) accounts for approximately 30% of non-small cell lung cancer (NSCLC) cases and is the second most common histological type of lung cancer. Anaplastic lymphoma kinase (ALK)-positive NSCLC accounts for only 2%-5% of all NSCLC cases, and is almost exclusively detected in patients with lung adenocarcinoma. Thus, ALK testing is not routinely performed in the LSCC population, and the efficacy of such treatment for ALK-rearranged LSCC remains unknown. Echinoderm microtubule associated protein like 4 (EML4)-ALK (V1) and TP53 co-mutations were identified by next generation sequencing (NGS) in this patient with advanced LSCC. On December 3, 2020, Ensatinib was taken orally and the efficacy was evaluated as partial response (PR). The progression-free survival (PFS) was 19 months. When the disease progressed, the medication was changed to Loratinib. To our knowledge, Enshatinib created the longest PFS of ALK-mutant LSCC patients treated with targeted therapy since literature review. Herein, we described one case treated by Enshatinib involving a patient with both EML4-ALK and TP53 positive LSCC, and the relevant literatures were reviewed for discussing the treatment of this rare disease.
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Humans ; Carcinoma, Non-Small-Cell Lung/drug therapy* ; Lung Neoplasms/pathology* ; Anaplastic Lymphoma Kinase/metabolism* ; Carcinoma, Squamous Cell/genetics* ; Mutation ; Cytoskeletal Proteins/genetics* ; Lung/pathology* ; Oncogene Proteins, Fusion/genetics* ; Protein Kinase Inhibitors/therapeutic use* ; Tumor Suppressor Protein p53/genetics*

BACKGROUND: Ischemic acute kidney injury (AKI) is a common syndrome associated with considerable mortality and healthcare costs. Up to now, the underlying pathogenesis of ischemic AKI remains incompletely understood, and specific strategies for early diagnosis and treatment of ischemic AKI are still lacking. Here, this study aimed to define the transcriptomic landscape of AKI patients through single-cell RNA sequencing (scRNA-seq) analysis in kidneys. METHODS: In this study, scRNA-seq technology was applied to kidneys from two ischemic AKI patients, and three human public scRNA-seq datasets were collected as controls. Differentially expressed genes (DEGs) and cell clusters of kidneys were determined. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, as well as the ligand-receptor interaction between cells, were performed. We also validated several DEGs expression in kidneys from human ischemic AKI and ischemia/reperfusion (I/R) injury induced AKI mice through immunohistochemistry staining. RESULTS: 15 distinct cell clusters were determined in kidney from subjects of ischemic AKI and control. The injured proximal tubules (PT) displayed a proapoptotic and proinflammatory phenotype. PT cells of ischemic AKI had up-regulation of novel pro-apoptotic genes including USP47 , RASSF4 , EBAG9 , IER3 , SASH1 , SEPTIN7 , and NUB1 , which have not been reported in ischemic AKI previously. Several hub genes were validated in kidneys from human AKI and renal I/R injury mice, respectively. Furthermore, PT highly expressed DEGs enriched in endoplasmic reticulum stress, autophagy, and retinoic acid-inducible gene I (RIG-I) signaling. DEGs overexpressed in other tubular cells were primarily enriched in nucleotide-binding and oligomerization domain (NOD)-like receptor signaling, estrogen signaling, interleukin (IL)-12 signaling, and IL-17 signaling. Overexpressed genes in kidney-resident immune cells including macrophages, natural killer T (NKT) cells, monocytes, and dendritic cells were associated with leukocyte activation, chemotaxis, cell adhesion, and complement activation. In addition, the ligand-receptor interactions analysis revealed prominent communications between macrophages and monocytes with other cells in the process of ischemic AKI. CONCLUSION Together, this study reveals distinct cell-specific transcriptomic atlas of kidney in ischemic AKI patients, altered signaling pathways, and potential cell-cell crosstalk in the development of AKI. These data reveal new insights into the pathogenesis and potential therapeutic strategies in ischemic AKI.
Humans ; Mice ; Animals ; Transcriptome/genetics* ; Ligands ; Kidney/metabolism* ; Acute Kidney Injury/metabolism* ; Ischemia/metabolism* ; Reperfusion Injury/metabolism* ; Sequence Analysis, RNA ; Adaptor Proteins, Signal Transducing/metabolism* ; Tumor Suppressor Proteins/metabolism*

This paper aimed to investigate the role and potential mechanism of p53 on primordial follicle activation. Firstly, the p53 mRNA expression in the ovary of neonatal mice at 3, 5, 7 and 9 days post-partum (dpp) and the subcellular localization of p53 were detected to confirm the expression pattern of p53. Secondly, 2 dpp and 3 dpp ovaries were cultured with p53 inhibitor Pifithrin-μ (PFT-μ, 5 μmol/L) or equal volume of dimethyl sulfoxide for 3 days. The function of p53 in primordial follicle activation was determined by hematoxylin staining and whole ovary follicle counting. The proliferation of cell was detected by immunohistochemistry. The relative mRNA levels and protein levels of the key molecules involved in the classical pathways associated with the growing follicles were examined by immunofluorescence staining, Western blot and real-time PCR, respectively. Finally, rapamycin (RAP) was used to intervene the mTOR signaling pathway, and ovaries were divided into four groups: Control, RAP (1 μmol/L), PFT-μ (5 μmol/L), PFT-μ (5 μmol/L) + RAP (1 μmol/L) groups. The number of follicles in each group was determined by hematoxylin staining and whole ovary follicle counting. The results showed that the expression of p53 mRNA was decreased with the activation of primordial follicles in physiological condition. p53 was expressed in granulosa cells and oocyte cytoplasm of the primordial follicles and growing follicles, and the expression of p53 in the primordial follicles was higher than that in the growing follicles. Inhibition of p53 promoted follicle activation and reduced the primordial follicle reserve. Inhibition of p53 promoted the proliferation of the granulosa cells and oocytes. The mRNA and protein expression levels of key molecules in the PI3K/AKT signaling pathway including AKT, PTEN, and FOXO3a were not significantly changed after PFT-μ treatment, while the expression of RPS6/p-RPS6, the downstream effectors of the mTOR signaling pathway, was upregulated. Inhibition of both p53 and mTOR blocked p53 inhibition-induced primordial follicle activation. Collectively, these findings suggest that p53 may inhibit primordial follicle activation through the mTOR signaling pathway to maintain the primordial follicle reserve.
Female ; Animals ; Mice ; Tumor Suppressor Protein p53/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Hematoxylin ; Signal Transduction/physiology* ; TOR Serine-Threonine Kinases ; Sirolimus ; RNA, Messenger