Project description:Growing evidence has indicated that miR-193 is involved in the initiation and progression of malignancy, such as bladder cancer, hepatocellular carcinoma, renal cell carcinoma, and colorectal cancer. Nevertheless, the mechanisms of miR-193 in the development of metastatic bladder cancer remains unknown. In the current study, we clarified the association of miR-193/N-myc was implicated in cancer metastasis. miR-193 expression increased in metastatic bladder cancer biopsies compared to the primary cases. Moreover, the elevation of miR-193 was correlated with the invasiveness, lymph node metastasis, and advanced stages of bladder cancer significantly. Downregulation of miR-193 by shRNA hampered proliferation and migration while inducing cell apoptosis. Furthermore, miR-193 sponged N-myc and diminished miR-103 expression. Overexpression of miR-193 released oncogene N-myc expression, leading to the promotion of cell proliferation and migration. Besides, knockout of miR-193 suppressed tumor growth in the human T24 mice models. Briefly, the present findings suggested that miR-193-N-myc were novel promising pathways for conquering bladder cancer progression.
Project description:The synergism between c-MYC and miR-17-19b, a truncated version of the miR-17-92 cluster, is well documented during tumor initiation. However, little is known about miR-17-19b function in established cancers. Here we investigate the role of miR-17-19b in c-MYC-driven lymphomas by integrating SILAC-based quantitative proteomics, transcriptomics and 3’ UTR analysis upon miR-17-19b overexpression. We identify over one hundred novel miR-17-19b targets, of which 40% are co-regulated by c-MYC. Down-regulation of a new miR-17/20 target Chek2 increases the recruitment of HuR to c-MYC transcripts, resulting in the inhibition of c-MYC translation and thus interfering with in vivo tumor growth. Hence, in established lymphomas, miR-17-19b fine-tunes c-MYC activity through a tight control of its function and expression, ultimately ensuring cancer cell homeostasis. Our data highlight the plasticity of miRNA function, reflecting changes in the mRNA landscape and 3’ UTR shortening at different stages of tumorigenesis.
Project description:The E3 ubiquitin ligase RNF112 exhibits significant downregulation in bladder cancer, correlating with disease progression and unfavorable prognosis. Experimental evidence from in vitro and in vivo studies indicates that RNF112 suppresses bladder cancer proliferation, migration, and lipid synthesis. Mechanistically, RNF112 interacts directly with the MBII domain of MYC through its N-terminal zinc finger motif. The catalytic site C97 of RNF112 facilitates K48-linked polyubiquitination of the K389 residue on the c-Myc protein, accelerating its degradation. The restoration of c-Myc expression has been shown to mitigate the inhibitory impacts of RNF112 on the growth, migration, and lipid synthesis of bladder cancer cells. Additionally, our research validates the interaction of c-Myc with the ACLY promoter, leading to an enhancement of its transcriptional activity. RNF112 exerts its inhibitory effects on lipid synthesis in bladder cancer through the regulation of c-Myc. In conclusion, RNF112 suppresses the proliferation, migration, and lipid synthesis of bladder cancer cells by facilitating the ubiquitin-mediated degradation of c-Myc.
Project description:Tumor necrosis factor (TNF) receptor-associated factor (TRAF)-interacting protein (TRAIP), a RING domain-containing E3 ligase, has emerged as a key player in safeguarding genome integrity and is closely linked to cancer. Here, we discovered that TRAIP exhibits low expression in bladder cancer (BLCA), which correlates with poor prognosis. TRAIP exerts inhibitory effects on bladder cancer cell proliferation and migration both in vitro and in vivo. MYC serves as a newly identified target for TRAIP, with direct interaction leading to the promotion of K48 polyubiquitination at K428/430 lysine residues, subsequently resulting in proteasome-dependent degradation and downregulation of MYC's transcriptional activity. This process effectively hinders the progression of bladder cancer. Restoration of MYC expression rescues the suppressed proliferation and migration of bladder cancer cells induced by TRAIP. Furthermore, our investigation also demonstrates that MYC binds to the transcriptional start region of TRAIP, exerting regulatory control over TRAIP transcription. Consequently, this interaction establishes a negative feedback loop that prevents excessive expression of MYC. In summary, our study uncovers a novel mechanism by which TRAIP inhibits the progression of bladder cancer through the ubiquitinated degradation of MYC.
Project description:Hitherto, most studies on POLD1 have mainly focused on the effect of POLD1 inactivation mutation in tumors. Nonetheless, the mechanism underlying high POLD1 expression in tumorigenesis remains elusive. Herein, we substantiated the pro-carcinogenic role of POLD1 in bladder cancer (BLCA) and found that POLD1 expression is related to malignancy and prognosis of BLCA. Next, we demonstrated that POLD1 could promote proliferation and metastasis of BLCA via MYC. Mechanistically, we demonstrated that POLD1 was able to stabilize MYC in a manner independent of DNA polymerase activity. POLD1 attenuated the FBXW7-mediated ubiquitination degradation of MYC by directly binding to the MYC homology box 1 domain competitively with FBXW7. Moreover, we found that POLD1 can form a complex with MYC to promote the transcriptional activity of MYC. MYC could also transcriptionally activate POLD1, forming a POLD1-MYC positive feedback loop to enhance the pro-carcinogenic effect of POLD1-MYC on BLCA. Overall, our study suggests a novel MYC-driven mechanism for BLCA, and POLD1 has the potential as a biomarker for BLCA.
Project description:MicroRNAs play an important role in the pathogenesis of different types of cancer including bladder cancer. MiR-21 has been identified to have an oncogenic function, while its inhibition suppresses tumor growth. Here, we followed an integrated bioinformatics and molecular analyses to identify the molecular mediators of miR-21 oncogenic function in bladder cancer and evaluate the therapeutic potential of a chemically-modified miR-21 inhibitor in bladder xenografts. MiR-21 expression was found to up-regulated in human bladder cancers relative to normal tissues and miR-21 inhibition suppressed bladder cancer cell properties, including growth, invasiveness and anchorage-independence. Intravenous administration of an antisense oligonucleotide against miR-21 harboring locked-nucleic-acid (LNA-miR-21) modifications blocked bladder tumor growth in vivo. Transcriptomic analysis of 28 bladder cancer cell lines revealed a gene signature that negatively correlated with miR-21 expression levels. Bioinformatics and 3’UTR luciferase assay analyses revealed a direct interaction between miR-21 the 3’UTR of PPP2R2A gene. Inhibition of PPP2R2A expression induced bladder cancer growth, suggesting its tumor suppressor function. Gene profiling followed by IPA network analysis revealed that PPP2R2A regulates the ERK1/2 molecular network. Taken together, PPP2R2A is the functional mediator of miR-21 oncogenic activity on bladder cancer and LNA-miR-21 could have a therapeutic potential in bladder cancer patients.
Project description:We recently identified a subset of down-regulated miRNAs such as miR-145 and miR-133a in bladder cancer. Cell growth inhibitions occurred in miR-145 and miR-133a transfectants compared with the controls, suggesting that both miRNAs function as tumor suppressors. The aims of our expression studies were identification of these miRNAs target genes.
Project description:Bladder cancer characterized by RNA methylation abnormalities and NOTCH pathway dysregulation exhibits high recurrence that remains the major obstacle for bladder cancer treatment. Targeting methyltransferase-like 3 (METTL3) and NOTCH signal is a potential strategy to block bladder cancer progression. However, the underlying mechanisms by which METTL3-manipulated NOTCH signal and its effect on bladder cancer tumorigenesis remain to be clarified. Here we showed that METTL3-guided m6A modification methylated pri-miR-146 at the flaking sequence, which was responsible for the pri-miR-146 maturation. Furthermore, NUMB/NOTCH2 axis was identified as the functional downstream target signal that mediated the pro-survival role of miR-146a-5p in bladder cancer cells. Therapeutically, the polypeptide melittin was demonstrated to induce apoptosis of bladder cancer cells in a METTL3-dependent manner. Importantly, METTL3 and miR-146a-5p were positively correlated with recurrence and poor prognosis of bladder cancer patient. Our studies indicate that METTL3/miR-146a-5p/NUMB/NOTCH2 axis could be a potential therapeutic target for recurrent bladder cancer treatment and METTL3 acts as a fate determinant that controls sensitivity of bladder cancer cells to melittin treatment.
Project description:We established stable miR-146a-5p overexpression T24 cells, then performed transcriptome profiling of miR-146a-5p overexpressing cells compared to control T24 cells to detect the molecular mechanisms of the miR-146a-5p’s effect on bladder cancer cells.