RNA modification has emerged as a crucial area of research in epigenetics, significantly influencing tumor biology by regulating RNA metabolism. N‐acetyltransferase 10 (NAT10)‐mediated N4‐acetylcytidine (ac4C) modification, the sole known acetylation in eukaryotic RNA, influences cancer pathogenesis and progression. NAT10 is the only writer of ac4C and catalyzes acetyl transfer on targeted RNA, and ac4C helps to improve the stability and translational efficiency of ac4C‐modified RNA. NAT10 is highly expressed and associated with poor prognosis in pan‐cancers. Based on its molecular mechanism and biological functions, ac4C is a central factor in tumorigenesis, tumor progression, drug resistance, and tumor immune escape. Despite the increasing focus on ac4C, the specific regulatory mechanisms of ac4C in cancer remain elusive. The present review thoroughly analyzes the current knowledge on NAT10‐mediated ac4C modification in cancer, highlighting its broad regulatory influence on targeted gene expression and tumor biology. This review also summarizes the limitations and perspectives of current research on NAT10 and ac4C in cancer, to identify new therapeutic targets and advance cancer treatment strategies.

The chromobox (CBX) proteins mediate epigenetic gene silencing and have been implicated in the cancer development. By analyzing eight CBX family members in TCGA dataset, we found that chromobox 7 (CBX7) was the most strikingly downregulated CBX family member in urinary bladder cancer (UBC), as compared to normal tissues. Though dysregulation of CBX7 has been reported in multiple cancers, its specific role and clinical relevance in UBC remain unclear. Herein, we found that frequent downregulation of CBX7 in UBC specimens, which was due to its promoter hypermethylation, was correlated with poor prognosis. The ectopic expression of CBX7 suppressed UBC cell proliferation, migration, invasion, and cancer stemness, whereas CBX7 depletion promoted cancer cell aggressiveness. Importantly, CBX7 overexpression in UBC cells inhibited tumorigenicity, whereas CBX7 depletion promoted the tumor development, indicating its tumor-suppressive role in UBC. Using RNA-seq and chromosome immunoprecipitation (ChIP) assays, we identified aldo-keto reductase family 1 member 10 (AKR1B10) as a novel downstream target of CBX7, which was negatively modulated by CBX7 in a PRC1-dependent manner and involved in stimulating ERK signaling. Consistently, AKR1B10 overexpression induced cancer cell aggressiveness, whereas suppression of AKR1B10 by siRNA or its small molecular inhibitor, oleanolic acid, reversed the CBX7 deficiency-induced cellular effects. AKR1B10 overexpression was negatively associated with CBX7 downregulation and predicted poor clinical outcomes in UBC patients. Taken together, our results indicate that CBX7 functions as a tumor suppressor to downregulate AKR1B10 and further inactivates ERK signaling. This CBX7/AKR1B10/ERK signaling axis may provide a new therapeutic strategy against UBC.

Urinary bladder cancer (UBC) is one of the most common urological cancer types. Muscle invasive bladder cancer possesses high propensity for metastasis with poor prognosis. Honokiol is a lignan isolated from Magnolia officinalis with high bioavailability and potent anticancer effects. The results of the present study demonstrated that honokiol significantly inhibited UBC cell migration and invasion in a dose‑dependent manner compared with the vehicle‑treated control group. In addition, honokiol treatment suppressed epithelial‑mesenchymal transition by induction of E‑cadherin and repression of N‑cadherin. Honokiol was capable of significantly downregulating the expression of cell invasion‑associated genes, steroid receptor coactivator‑3 (SRC‑3), matrix metalloproteinase (MMP)‑2 and Twist1. Notably, the inhibition of UBC cell invasion by honokiol was reversed by reintroduction of oncoprotein SRC‑3 expression, with the restoration of MMP‑2 and Twist1, and reduction of E‑cadherin expression. Furthermore, the results of the luciferase assay confirmed that SRC‑3 could regulate Twist1 promoter activity. Taken together, the results of the present study suggest that honokiol is a promising agent against UBC cell invasion via downregulation of SRC‑3 and its target genes.

Bladder cancer (BC) belongs to one of the most common and highly heterogeneous malignancies. Ferroptosis is a newly discovered regulated cell death (RCD), characterized by accumulation of toxic lipid peroxides, and plays a crucial role in tumor progression. Here, we conducted a comprehensive analysis on the transcriptomics data of ferroptosis-related genes in BC based on The Cancer Genome Atlas (TCGA) and three Gene Expression Omnibus (GEO) datasets. In our study, a 6-gene signature was identified based on the potential prognostic ferroptotic regulatory genes. Furthermore, our signature revealed a good independent prognostic ability in BC. Patients with low-risk score exhibited higher FGFR3 mutation rates while high risk score had a positive association with higher RB1 mutation rates. Meanwhile, higher proportions of macrophages were observed in high BC risk group simultaneously with four methods. Unexpectedly, the risk score showed a significant positive correlation with epithelial-mesenchymal transition (EMT) status. Functional assays indicated that CRYAB and SQLE knockdown was associated with attenuated invasion capacity. Our study revealed a ferroptosis-related risk model for predicting prognostic and BC progression. Our results indicate that targeting ferroptosis may be a therapeutic strategy for BC.

Purpose: The combination of Xiaozheng decoction with postoperative intravesical instillation has been shown to improve the prognosis of bladder cancer patients and prevent recurrence. However, the mechanisms underlying the efficacy of this herbal formula remain largely unclear. This research aims to identify the important components of Xiaozheng decoction and explore their anti-bladder cancer effect and mechanism using network pharmacology-based experiments. Methods: The chemical ingredients of each herb in the Xiaozheng decoction were collected from the Traditional Chinese Medicine (TCM) database. Network pharmacology was employed to predict the target proteins and pathways of action. Disease databases were utilized to identify target genes associated with bladder cancer. A Protein–Protein Interaction (PPI) network was constructed to illustrate the interaction with intersected target proteins. Key targets were identified using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analysis. A compound-target-pathway network was established after molecular docking predictions. In vitro experiments with bladder cancer cell lines were conducted using core chemical components confirmed by ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-qTOF-MS) to verify the conclusions of network pharmacology. Results: 45 active compounds were extracted, and their relationships with Traditional Chinese Medicines (TCMs) and protein targets were presented, comprising 7 herbs, 45 active compounds, and 557 protein targets. The intersection between potential TCM target genes and bladder cancer-related genes yielded 322 genes. GO and KEGG analyses indicated that these targets may be involved in numerous cancer-related pathways. Molecular docking results showed that candidate compounds except mandenol could form stable conformations with the receptor. In vitro experiments on three bladder cancer cell lines demonstrated that quercetin and two other impressive new compounds, bisdemethoxycurcumin (BDMC) and kumatakenin, significantly promoted cancer cell apoptosis through the B-cell lymphoma 2/Bcl-2-associated X (Bcl-2/BAX) pathway and inhibited proliferation and migration through the glycogen synthase kinase 3 beta (GSK3β)/β-catenin pathway. Conclusion: By employing network pharmacology and conducting in vitro experiments, the mechanism of Xiaozheng decoction’s effect against bladder cancer was tentatively elucidated, and its main active ingredients and targets were identified, providing a scientific basis for future research.

Ten-eleven translocation 1 (TET1) is a member of methylcytosine dioxygenase, which catalyzes 5-methylcytosine (5 mC) to 5-hydroxymethylcytosine (5 hmC) to promote the demethylation process. The dysregulated TET1 protein and 5 hmC level were reported to either suppress or promote carcinogenesis in a cancer type-dependent manner. Currently, the role of TET1 in the development of urinary bladder cancer (UBC) and its underlying molecular mechanisms remain unclear. Herein, we found that TET1 expression was downregulated in UBC specimens compared with normal urothelium and was inversely related to tumor stage and grade and overall survival, suggesting its negative association with UBC progression. TET1 silencing in UBC cells increased cell proliferation and invasiveness while the ectopic expression of wild-type TET1-CD, but not its enzymatic inactive mutant, reversed these effects and suppressed tumorigenicity in vivo. In addition, as a direct regulator of TET1 activity, vitamin C treatment increased 5 hmC level and inhibited the anchorage-independent growth and tumorigenicity of UBC cells. Furthermore, we found that TET1 maintained the hypomethylation in the promoter of the AJAP1 gene, which codes for adherens junction-associated protein 1. The downregulation of AJAP1 reversed TET1-CD-induced nuclear translocation of β-catenin, thus inhibiting the expression of its downstream genes. In human UBC specimens, AJAP1 is frequently downregulated and positively associated with TET1. Notably, low expression levels of both TET1 and AJAP1 predict poor prognosis in UBC patients. In conclusion, we found that the frequently downregulated TET1 level reduces the hydroxymethylation of AJAP1 promoter and subsequently activates β-catenin signaling to promote UBC development. The downregulation of both TET1 and AJAP1 might be a promising prognostic biomarker for UBC patients.