Circular RNAs are a new class of non-coding RNAs that have been shown to play critical roles in the development and progression of renal cell carcinoma (RCC). However, little is known about the functional mechanisms and therapeutic role of ciRS-7 in RCC. A series of in vitro and in vivo experiments were performed to investigate the functional mechanism and therapeutic role of ciRS-7, such as real-time quantitative PCR, CCK-8, wound healing, transwell, colony formation, Edu, tumor xenograft and lung metastasis in NSG mice. RNA pull-down, dual luciferase reporter, fluorescence in situ hybridization (FISH) and rescue assays were used to determine the relationship between ciRS-7, miR-139-3p and TAGLN. In addition, we constructed PBAE/si-ciRS-7 nanocomplexes with PBAE material to evaluate the therapeutic effect of the nanocomplexes on tumor in vivo. ciRS-7 was highly expressed in RCC tumor tissues and cell lines, and high ciRS-7 expression correlated with tumor size, high Fuhrman grade and poor survival. Depletion of ciRS-7 significantly inhibited RCC cell proliferation, invasion, tumor growth and metastasis in vivo, while overexpression of ciRS-7 had the opposite effect. Mechanistically, ciRS-7 acts as a "ceRNA" for miR-139-3p to prevent TAGLN degradation and promoting RCC progression and metastasis via the PI3K/AKT signaling pathway. In addition, miR-139-3p mimics or inhibitor could reverse the altered malignant tumor behavior caused by ciRS-7 overexpression or silencing. Furthermore, the PBAE/siciRS-7 nanocomplexes could significantly inhibit RCC tumor progression and metastasis in vivo. ciRS-7 acts as a tumor promoter by regulating the miR-139-3p/TAGLN axis and activating the PI3K/AKT signaling pathway to promote RCC progression and metastasis. Drug development of PBAE/si-ciRS-7 nanocomplexes targeting ciRS-7 may represent a promising gene therapeutic strategy for RCC.

Long non-coding RNA XIST promotes cell growth and metastasis through regulating miR-139-5p mediated Wnt/-catenin signaling pathway in bladder cancer Long non-coding RNA XIST promotes cell growth and metastasis through regulating miR-139-5p mediated Wnt/β-catenin signaling pathway in bladder cancer

Accumulating studies have confirmed that PIWI-interacting RNAs (piRNAs) are considered epigenetic effectors in cancer. We performed piRNA microarray expression analysis on renal cell carcinoma (RCC) tumor tissues and paired normal tissues and performed a series of in vivo and in vitro experiments to explore piRNAs associated with RCC progression and investigate their functional mechanisms. We found that piR-1742 was highly expressed in RCC tumors and that patients with high piR-1742 expression had a poor prognosis. Inhibition of piR-1742 significantly reduced tumor growth in RCC xenograft and organoid models. Mechanistically, piRNA-1742 regulates the stability of USP8 mRNA by binding directly to hnRNPU, which acts as a deubiquitinating enzyme that inhibits the ubiquitination of MUC12 and promotes the development of malignant RCC. Subsequently, nanotherapeutic systems loaded with piRNA-1742 inhibitors were found to effectively inhibit the metastasis and growth of RCC in vivo. Therefore, this study highlights the functional importance of piRNA-related ubiquitination in RCC and demonstrates the development of a related nanotherapeutic system, possibly contributing to the development of therapeutic approaches for RCC.

Background: Clear cell renal cell carcinoma (ccRCC) arises from the renal parenchymal epithelium and is the predominant malignant entity of renal cancer, exhibiting increasing incidence and mortality rates over time. SEC14-like 3 (SEC14L3) has emerged as a compelling target for cancer intervention; nevertheless, the precise clinical implications and molecular underpinnings of SEC14L3 in ccRCC remain elusive. Methods: By leveraging clinical data and data from the TCGA-ccRCC and GEO datasets, we investigated the association between SEC14L3 expression levels and overall survival rates in ccRCC patients. The biological role and mechanism of SEC14L3 in ccRCC were investigated via in vivo and in vitro experiments. Moreover, siRNA-SEC14L3@PDA@MUC12 nanoparticles (SSPM-NPs) were synthesized and assessed for their therapeutic potential against SEC14L3 through in vivo and in vitro assays. Results: Our investigation revealed upregulated SEC14L3 expression in ccRCC tissues, and exogenous downregulation of SEC14L3 robustly suppressed the malignant traits of ccRCC cells. Mechanistically, knocking down SEC14L3 facilitated the ubiquitination-mediated degradation of ribosomal protein S3 (RPS3) and augmented IκBα accumulation in ccRCC. This concerted action thwarted the nuclear translocation of P65, thereby abrogating the activation of the nuclear factor kappa B (NFκB) signaling pathway and impeding ccRCC cell proliferation and metastasis. Furthermore, diminished SEC14L3 levels exerted a suppressive effect on NFKB1 expression within the NFκB signaling cascade. NFKB1 functions as a transcriptional regulator capable of binding to the SEC14L3 enhancer and promoter, thereby promoting SEC14L3 expression. Consequently, the inhibition of SEC14L3 expression was further potentiated, thus forming a positive feedback loop. Additionally, we observed that downregulation of SEC14L3 significantly increased the sensitivity of ccRCC cells to sunitinib. The evaluation of SSPM-NPs nanotherapy highlighted its effectiveness in combination with sunitinib for inhibiting ccRCC growth. Conclusion: Our findings not only underscore the promise of SEC14L3 as a therapeutic target but also unveil an SEC14L3/RPS3/NFκB positive feedback loop that curtails ccRCC progression. Modulating SEC14L3 expression to engage this positive feedback loop might herald novel avenues for ccRCC treatment.