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

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

Genes, p53 ; Genetic Predisposition to Disease ; Germ-Line Mutation ; Humans ; Li-Fraumeni Syndrome/genetics* ; Tumor Suppressor Protein p53/genetics*

BACKGROUND: The pathogenesis of osteosarcoma (OS) is still unclear, and it is still necessary to find new targets and drugs for anti-OS. This study aimed to investigate the role and mechanism of the anti-OS effects of miR-296-5p. METHODS: We measured the expression of miR-296-5p in human OS cell lines and tissues. The effect of miR-296-5p and its target gene staphylococcal nuclease and tudor domain containing 1 on proliferation, migration, and invasion of human OS lines was examined. The Student's t test was used for statistical analysis. RESULTS: We found that microRNA (miR)-296-5p was significantly downregulated in OS cell lines and tissues (control vs. OS, 1.802 ± 0.313 vs. 0.618 ± 0.235, t = 6.402, P < 0.01). Overexpression of miR-296-5p suppressed proliferation, migration, and invasion of OA cells. SND1 was identified as a target of miR-296-5p by bioinformatic analysis and dual-luciferase reporter assay. Overexpression of SND1 abrogated the effects induced by miR-296-5p upregulation (miRNA-296-5p vs. miRNA-296-5p + SND1, 0.294 ± 0.159 vs. 2.300 ± 0.277, t = 12.68, P = 0.003). CONCLUSION Our study indicates that miR-296-5p may function as a tumor suppressor by targeting SND1 in OS.
Bone Neoplasms/genetics* ; Cell Line, Tumor ; Cell Movement/genetics* ; Cell Proliferation/genetics* ; Endonucleases/genetics* ; Gene Expression Regulation, Neoplastic ; Genes, Tumor Suppressor ; Humans ; MicroRNAs/genetics* ; Osteosarcoma/genetics*

Carbonic Anhydrase IV ; genetics ; Chloride Channels ; genetics ; Colorectal Neoplasms ; genetics ; Databases, Genetic ; Gene Expression Regulation, Neoplastic ; Genes, Tumor Suppressor ; Humans ; Inhibin-beta Subunits ; genetics

Objective: To explore the clinical implications and prognostic value of TP53 gene mutation and deletion in patients with myelodysplastic syndromes (MDS) . Methods: 112-gene targeted sequencing and interphase fluorescence in situ hybridization (FISH) were used to detect TP53 mutation and deletion in 584 patients with newly diagnosed primary MDS who were admitted from October 2009 to December 2017. The association of TP53 mutation and deletion with several clinical features and their prognostic significance were analyzed. Results: Alterations in TP53 were found in 42 (7.2%) cases. Of these, 31 (5.3%) cases showed TP53 mutation only, 8 (1.4%) cases in TP53 deletion only, 3 (0.5%) cases harboring both mutation and deletion. A total of 37 mutations were detected in 34 patients, most of them (94.6%) were located in the DNA binding domain (exon5-8) , the remaining 2 were located in exon 10 and splice site respectively. Patients with TP53 alterations harbored significantly more mutations than whom without alterations (z=-2.418, P=0.016) . The median age of patients with TP53 alterations was higher than their counterparts[60 (21-78) years old vs 52 (14-83) years old, z=-2.188, P=0.029]. TP53 alterations correlated with complex karyotype and International prognostic scoring system intermediate-2/high significantly (P<0.001) . Median overall survival of patients with TP53 alterations was shorter than the others[13 (95%CI 7.57-18.43) months vs not reached, χ(2)=12.342, P<0.001], while the significance was lost during complex karyotype adjusted analysis in multivariable model. Conclusion: TP53 mutation was more common than deletion in MDS patients. The majority of mutations were located in the DNA binding domain. TP53 alterations were strongly associated with complex karyotype and always coexisted with other gene mutations. TP53 alteration was no longer an independent prognostic factor when complex karyotype were occurred in MDS.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Genes, p53 ; Humans ; In Situ Hybridization, Fluorescence ; Middle Aged ; Mutation ; Myelodysplastic Syndromes/genetics* ; Prognosis ; Tumor Suppressor Protein p53 ; Young Adult

Objective: To analyze the survival and first-line immune-chemotherapy (CIT) of chronic lymphocytic leukemia (CLL) with abnormal TP53 gene in the era of traditional CIT. Methods: The clinical data of 118 CLL patients diagnosed from January 2003 to August 2017 were collected. Survival was analyzed according to indicators including sex, age, Binet risk stratification, B symptoms, β(2)-microglobulin (β(2)-MG) , immunoglobulin heavy chain variable region gene (IGHV) mutation status, chromosome karyotype and TP53 gene deletion/mutation. The efficacy of first-line CIT of 101 CLL patients was further analyzed. Results: Among 118 patients, median progression-free survival (PFS) was 12 (95%CI 10.148-13.852) months and median overall survival (OS) was 53 (95%CI 41.822-64.178) months, only 30.5% patients survived over 5 years. Low β(2)-MG<3.5 mg/L indicated longer PFS (P=0.027) , female and Binet A patients had longer OS (P=0.011 and 0.013, respectively) . Of 118 patients, 17 (14.4%) didn't receive any therapy until follow-up time or the dead time. Among the 101 patients who received ≥1 CIT, median time to first treatment (TTFT) was 1 (0-62) months, patients in Binet A had longer TTFT (P<0.001) compared to the patients in Binet B/C. According to statistical needs, we divided those first-line CIT into four groups: there were 30 cases (29.7%) in mild chemotherapy group (mainly treated with nitrogen mustard phenylbutyrate or rituximab alone) , 32 cases (31.7%) in the fludarabine-containing group, 23 cases (22.8%) in high-dose methyprednisolone (HDMP) containing group and 16 cases (15.8%) in the other chemotherapy group. The first regimen contained HDMP can bring longer PFS (P<0.001) , however the OS between four groups had no statistical differences. Conclusion: CLL patients with abnormal TP53 gene had poor response to immunotherapy, rapid clinical progressing, first-line immunotherapy containing HDMP can prolong PFS and will create an opportunity for patients to participate in clinical trials of novel drugs.
Antineoplastic Combined Chemotherapy Protocols ; Female ; Genes, p53 ; Humans ; Immunotherapy ; Leukemia, Lymphocytic, Chronic, B-Cell/genetics* ; Survival Analysis ; Tumor Suppressor Protein p53/genetics*

Adult ; Cytogenetics ; Genes, p53 ; Humans ; Leukemia, Myeloid, Acute/genetics* ; Mutation ; Prognosis ; Tumor Suppressor Protein p53/genetics*

PURPOSE: Tumor protein p53-regulated apoptosis-inducing protein 1 (TP53AIP1) functions in various cancers. We studied the effect and molecular mechanism of TP53AIP1 in breast cancer. METHODS: The degree of correlation between TP53AIP1 expression and overall survival in patients with breast cancer was obtained from the online The Cancer Genome Atlas database. Six of the TP53AIP1 levels in the tumor and adjacent non-tumor tissues randomly selected from 38 breast cancer patients were determined. Transgenic technology was used to enhance the expression of TP53AIP1 in breast cancer cell lines, MDA-MB-415 and MDA-MB-468, and to observe the effects of gene overexpression on the proliferation, cell cycle, and apoptosis of breast cancer cells. The molecular mechanism of association between cell cycle- and apoptosis-related factors and the phosphoinositide 3-kinases/protein kinase B (PI3K/Akt) pathway was also studied. RESULTS: The messenger RNA and protein expression levels of TP53AIP1 in cancer tissues were significantly lower than those in the control group. TP53AIP1 overexpression inhibits cell viability. The mechanism of TP53AIP1 inhibition of proliferation and growth of breast cancer cells includes cell cycle arrest, apoptosis promotion (p < 0.01), promotion of the expression of cleaved-caspase-3 (p < 0.01), cleaved-caspase-9 (p < 0.01), B cell lymphoma/leukemia-2 (Bcl-2)-associated X protein, and p53 (p < 0.01), and the inhibition of Bcl-2, Ki67, and PI3K/Akt pathways (p < 0.01). CONCLUSION: TP53AIP1 may be a novel tumor suppressor gene in breast cancer and can potentially be used as an effective target gene for the treatment of breast cancer.
Apoptosis ; Breast Neoplasms ; Breast ; Cell Cycle Checkpoints ; Cell Line ; Cell Proliferation ; Cell Survival ; Genes, p53 ; Genes, Tumor Suppressor ; Genome ; Humans ; Phosphotransferases ; RNA, Messenger

Medulloblastoma is considered one of the most threatening malignant brain tumors with an extremely high mortality rate in children. In the medulloblastoma, there are several genes and mutations found to work in an unregulated manner that works together to push the cells into a cancerous state. With the discovery of non-coding RNAs such as microRNAs (miRNAs), it has been shown that a different layer of gene regulations may be disrupted which would cause cancer. This fact led scientists to put their focus on the role of miRNAs in cancer. A mature miRNA contains a seed sequence which gives the miRNA to identify and attach to the interest mRNA; this attachment may lead degradation of mRNA or suppress of translation of the mRNA. The expression of miRNAs in medulloblastoma shows that some of these non-coding RNAs are overexpressed (OncomiRs) which help cells to proliferate and keep their stemness features. On the other hand, there are other forms of these miRNAs which normally inhibit cell proliferation and promote cell differentiation (tumor suppressor). These are down-regulated during cancer progression. In this systematic review, we attempted to gather several important studies on miRNAs’ role in medulloblastoma tumors and the importance of these non-coding RNAs in the future study of cancer.
Brain Neoplasms ; Cell Differentiation ; Cell Proliferation ; Child ; Genes, Tumor Suppressor ; Hand ; Humans ; Medulloblastoma ; MicroRNAs ; Mortality ; Oncogenes ; RNA, Messenger ; RNA, Untranslated ; Social Control, Formal