CircLIFR suppresses hepatocellular carcinoma progression by sponging miR-624-5p and inactivating the GSK-3β/β-catenin signaling pathway

Circular RNAs have been reported to play essential roles in the tumorigenesis and progression of various cancers. However, the biological processes and mechanisms involved in hepatocellular carcinoma (HCC) remain unclear. Initial RNA-sequencing data and qRT-PCR results in our cohort showed that hsa_circ_0072309 (also called circLIFR) was markedly downregulated in HCC tissues. Kaplan–Meier analysis indicated that higher levels of circLIFR in HCC patients correlated with favorable overall survival and recurrence-free survival rates. Both in vitro and in vivo experiments indicated that circLIFR inhibited the proliferation and invasion abilities of HCC cells. We therefore conducted related experiments to explore the mechanism of circLIFR in HCC. Fluorescence in situ hybridization results revealed that circLIFR was mainly located in the cytoplasm, and RNA immunoprecipitation assays indicated that circLIFR was significantly enriched by Ago2 protein. These results suggested that circLIFR may function as a sponge of miRNAs to regulate HCC progression. We further conducted bioinformatics prediction as well as dual-luciferase reporter assays, and the results of which showed that circLIFR could sponge miR-624-5p to stabilize glycogen synthase kinase 3β (GSK-3β) expression. Loss and gain of function experiments demonstrated that regulation of the expression of miR-624-5p or GSK-3β markedly affected HCC progression induced by circLIFR. Importantly, we also proved that circLIFR could facilitate the degradation of β-catenin and prevent its translocation to the nucleus in HCC cells. Overall, our study demonstrated that circLIFR acts as a tumor suppressor in HCC by regulating miR-624-5p and inactivating the GSK-3β/β-catenin signaling pathway.Subject terms: Oncogenes, Liver cancer     

miR-17-5p accelerates cervical cancer cells migration and invasion via the TIMP2/MMPs signaling cascade

Cytotechnology - Cervical cancer (CC) is a common gynecological tumor, ranking second in the female reproductive system tumor. The work aims to study the function of miR-17-5p in the occurrence and...     

SNHG1 represses the anti-cancer roles of baicalein in cervical cancer through regulating miR-3127-5p/FZD4/Wnt/β-catenin signaling

As a flavonoid, baicalein exhibits remarkable anti-cancer roles in several cancers. However, the factors regulating the antitumorigenic roles of baicalein in cervical cancer remain undefined. Here, we revealed that long noncoding RNA SNHG1 is implicated in the tumor-suppressive roles of baicalein. Functional assays demonstrated that ectopic expression of SNHG1 attenuates the roles of baicalein in repressing cervical cancer cell viability, inducing apoptosis, and repressing migration. SNHG1 silencing promotes the tumor-suppressive roles of baicalein in cervical cancer cell viability, apoptosis, and migration. Xenograft assays showed that SNHG1 reverses the tumor-suppressive roles of baicalein in repressing cervical cancer growth in vivo. Mechanistic investigations revealed that SNHG1 directly binds miR-3127-5p and up-regulates FZD4, a target of miR-3127-5p. Via regulating miR-3127-5p/FZD4, SNHG1 activates Wnt/β-catenin signaling. Moreover, SNHG1 reverses the repressive role of baicalein on Wnt/β-catenin signaling. The effect of SNHG1 on the antitumorigenic process of baicalein was abolished by Wnt/β-catenin signaling inhibitor ICG-001. Together, our observations demonstrated that SNHG1 represses the tumor-suppressive roles of baicalein in cervical cancer through regulating miR-3127-5p/FZD4/Wnt/β-catenin axis, and suggested that targeting SNHG1 represents a potential strategy to enhance the tumor-suppressive roles of baicalein in cervical cancer.Impact statementBaicalein exhibits anti-cancer roles in several cancers. However, the factors influencing the antitumorigenic efficiencies of baicalein in CC remain largely unclear. Here, we provide convincing evidences that lncRNA SNHG1 attenuates the tumor-suppressive roles of baicalein in CC cell viability, apoptosis, migration, and CC tumor growth. This study further demonstrates that the influences of SNHG1 in the antitumorigenic process of baicalein are achieved through modulating the miR-3127-5p/FZD4Wnt/β-catenin axis. SNHG1 attenuates the repressive role of baicalein on Wnt/β-catenin. Therefore, SNHG1 is a novel modulator of the tumor-suppressive roles of baicalein and SNHG1 represents a therapeutic intervention target to reinforce the tumor-suppressive roles of baicalein in CC.     

CircMTO1 suppresses hepatocellular carcinoma progression via the miR-541-5p/ZIC1 axis by regulating Wnt/β-catenin signaling pathway and epithelial-to-mesenchymal transition

CircRNA mitochondrial tRNA translation optimization 1 (circMTO1) functions as a tumor suppressor usually and is related to the progression of many tumors, including hepatocellular carcinoma (HCC). CircMTO1 is downregulated in HCC as compared to adjacent nontumor tissue, which may suppress the HCC progression by certain signal pathways. However, the underlying signal pathway remains largely unknown. The interactions between circMTO1 and miR-541-5p were predicted through bioinformatics analysis and verified using pull-down and dual-luciferase reporter assays. CCK-8, transwell, and apoptosis assays were performed to determine the effect of miR-541-5p on HCC progression. Using bioinformatic analysis, dual-luciferase reporter assay, RT-qPCR, and western blot, ZIC1 was found to be the downstream target gene of miR-541-5p. The regulatory mechanisms of circMTO1, miR-541-5p, and ZIC1 were investigated using in vitro and in vivo rescue experiments. The results depicted that silencing circMTO1 or upregulating miR-541-5p expression facilitated HCC cell proliferation, migration, and invasion and inhibited apoptosis. CircMTO1 silencing upregulated the expression of downstream ZIC1 regulators of the Wnt/β-catenin pathway markers, β-catenin, cyclin D1, c-myc, and the mesenchymal markers N-cadherin, Vimentin, and MMP2, while the epithelial marker E-cadherin was downregulated. MiR-541-5p knockdown had the opposite effect and reversed the effect of circMTO1 silencing on the regulation of downstream ZIC1 regulators. Intratumoral injection of miR-541-5p inhibitor suppressed tumor growth and reversed the effect of circMTO1 silencing on the promotion of tumor growth in HCC. These findings indicated that circMTO1 suppressed HCC progression via the circMTO1/ miR-541-5p/ZIC1 axis by regulating Wnt/β-catenin signaling and epithelial-to-mesenchymal transition, making it a novel therapeutic target. Subject terms: Cancer therapy, Liver cancer, Tumour-suppressor proteins     

Dok5 regulates proliferation and differentiation of osteoblast via canonical Wnt/β-catenin signaling

Objective:In bone tissue engineering, the use of osteoblastic seed cells has been widely adopted to mediate the osteogenic differentiation so as to prompt bone regeneration and repair. It is hypothesized that Dok5 can regulate the proliferation and differentiation of osteoblasts. In this study, the role of Dok5 in osteoblast proliferation and differentiation was investigated.Methods:A lentiviral vector to silence Dok5 was transferred to C3H10, 293T and C2C12 cells. CCK-8 assay was used to detect the cell proliferation. Cells were stained by ALP and AR-S staining. Western blot and RT-PCR were used to detect the expression levels of related factors.Results:Dok5 expression level was gradually up-regulated during the osteoblast differentiation. Dok5 silencing down-regulated the expression levels of osteogenic biosignatures OPN, OCN, and Runx2 and suppressed the osteogenesis. Additionally, the osteoblast proliferation and canonical Wnt/β-catenin signaling were suppressed upon Dok5 knockdown, β-catenin expression level was significantly down-regulated in the knockdown group, while the expression levels of GSK3-β and Axin, negative regulators in the Wnt signaling pathway, were up-regulated. Furthermore, overexpression of Dok5 promoted the proliferation and osteogenesis and activated the canonical Wnt/β-catenin signaling pathway.Conclusion:Dok5 may regulate the osteogenic proliferation and differentiation via the canonical Wnt/β-catenin signaling pathway.     

High dose androgen suppresses natural killer cytotoxicity of castration-resistant prostate cancer cells via altering AR/circFKBP5/miRNA-513a-5p/PD-L1 signals

Most advanced prostate cancer (PCa) patients initially respond well to androgen deprivation therapy, but almost all eventually develop castration-resistant prostate cancer (CRPC). Early studies indicated the bipolar androgen therapy via a cycling of high dose and low dose of androgen to suppress PCa growth might be effective in a select patient population. The detailed mechanisms, however, remain unclear. Here we found the capacity of natural killer (NK) cells to suppress the CRPC cells could be suppressed by a high dose of dihydrotestosterone (DHT). Mechanism dissection indicates that transactivated AR can increase circularRNA-FKBP5 (circFKBP5) expression, which could sponge/inhibit miR-513a-5p that suppresses the PD-L1 expression via direct binding to its 3ʹUTR to negatively impact immune surveillance from NK cells. Preclinical data from in vitro cell lines and an in vivo mouse model indicate that targeting PD-L1 with sh-RNA or anti-PD-L1 antibody can enhance the high dose DHT effect to better suppress CRPC cell growth. These findings may help us to develop novel therapies via combination of high dose androgen with PD-1/PD-L1 checkpoint inhibitors to better suppress CRPC progression.Subject terms: Cell signalling, Prostate cancer     

Circ-ERBB2 knockdown sensitized colorectal cancer cells to 5-FU via miR-181a-5p/PTEN/Akt pathway

Colorectal cancer (CRC) is the fourth most deadly cancer worldwide, drug resistance impedes treatment of CRC. It is still urgent to find new molecular targets to improve the sensitivity of chemotherapeutic drugs. In this study, circ-ERBB2 was upregulated in CRC cells. Upregulation of circ-ERBB2 promoted CRC cells proliferation and clone formation, but inhibited apoptosis. We identified miR-181a-5p as circ-ERBB2's target. The effect of miR-181a-5p on CRC cells was contrary to circ-ERBB2, miR-181a-5p downregulation abolished the function of circ-ERBB2 silencing in CRC cells. In addition, phosphatase and tensin homolog (PTEN) was verified as miR-181a-5p's downstream target, circ-ERBB2 activates the Akt pathway and inhibits cell apoptosis through modulating miR-181a-5p/PTEN. Circ-ERBB2 silencing significantly reduced CRC cell resistance to 5-FU. miR-181a-5p downregulation abolished the role of circ-ERBB2 knockdown in CRC cell resistance to 5-FU. In conclusion, upregulation of circ-ERBB2 promoted the malignancy of CRC and reduced CRC cell resistance to 5-FU. Besides, additional mechanism study provided a novel regulatory pathways that circ-ERBB2 knockdown promoted CRC cell sensitivity to 5-FU by regulating miR-181a-5p/PTEN/Akt pathway. This research indicated that circ-ERBB2 may be a valuable biomarker for the diagnosis and treatment of CRC.     

Homoharringtonine inhibited breast cancer cells growth via miR-18a-3p/AKT/mTOR signaling pathway

Homoharringtonine (HHT), a natural alkaloid derived from the cephalotaxus, exhibited its anti-cancer effects in hematological malignancies clinically. However, its pesticide effects and mechanisms in treating solid tumors remain unclear. In this study, we found that HHT was capable of inhibiting tumor growth after 5-days treatment of breast cancer cells, MCF-7, in vivo. Furthemore, HHT also significantly inhibited the cancer cell growth and induced cell apoptosis in vitro. miRNA sequencing proved miR-18a-3p was noticeably downregulated in the cells after HHT treatment. Moreover, downregulating miR-18a-3p increased HHT-induced cell apoptosis; our data supported that HHT suppressed miR-18a-3p expression and inhibited tumorigenesis might via AKT-mTOR signaling pathway. In conclusion: our study proved that HHT suppressed breast cancer cell growth and promoted apoptosis mediated by regulating of the miR-18a-3p-AKT-mTOR signaling pathway, HHT may be a promising antitumor agent in breast cancer treatment.     

NOP14 regulates the growth,migration, and invasion of colorectal cancer cells by modulating the NRIP1/GSK-3β/β-catenin signaling pathway

Colorectal cancer (CRC) is the third most common cancer diagnosed worldwide. Recently, nucleolar complex protein 14 (NOP14) has been discovered to play a critical role in cancer development and progression, but the mechanisms of action of NOP14 in colorectal cancer remain to be elucidated. In this study, we used collected colorectal cancer tissues and cultured colorectal cancer cell lines (SW480, HT29, HCT116, DLD1, Lovo), and measured the mRNA and protein expression levels of NOP14 in colorectal cancer cells using qPCR and Western blotting. GFP-NOP14 was constructed and siRNA fragments against NOP14 were synthesized to investigate the importance of NOP14 for the development of colorectal cells. Transwell migration assays were used to measure cell invasion and migration, CCK-8 kits were used to measure cell activity, and flow cytometry was applied to the observation of apoptosis. We found that both the mRNA and protein levels of NOP14 were significantly upregulated in CRC tissues and cell lines. Overexpression of GFP-NOP14 markedly promoted the growth, migration, and invasion of the CRC cells HT19 and SW480, while genetic knockdown of NOP14 inhibited these behaviors. Overexpression of NOP14 promoted the expression of NRIP1 and phosphorylated inactivation of GSK-3β, leading to the upregulation of β-catenin. Genetic knockdown of NOP14 had the opposite effect on NRIP1/GSK-3/β-catenin signals. NOP14 therefore appears to be overexpressed in clinical samples and cell lines of colorectal cancer, and promotes the proliferation, growth, and metastasis of colorectal cancer cells by modulating the NRIP1/GSK-3β/β-catenin signaling pathway.Key words: Colorectal cancer, NOP14, proliferation, migration, invasion     

The TTYH3/MK5 Positive Feedback Loop regulates Tumor Progression via GSK3-β/β-catenin signaling in HCC

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide, and identification of novel targets is necessary for its diagnosis and treatment. This study aimed to investigate the biological function and clinical significance of tweety homolog 3 (TTYH3) in HCC. TTYH3 overexpression promoted cell proliferation, migration, and invasion and inhibited HCCM3 and Hep3B cell apoptosis. TTYH3 promoted tumor formation and metastasis in vivo. TTYH3 upregulated calcium influx and intracellular chloride concentration, thereby promoting cellular migration and regulating epithelial-mesenchymal transition-related protein expression. The interaction between TTYH3 and MK5 was identified through co-immunoprecipitation assays and protein docking. TTYH3 promoted the expression of MK5, which then activated the GSK3β/β-catenin signaling pathway. MK5 knockdown attenuated the activation of GSK3β/β-catenin signaling by TTYH3. TTYH3 expression was regulated in a positive feedback manner. In clinical HCC samples, TTYH3 was upregulated in the HCC tissues compared to nontumor tissues. Furthermore, high TTYH3 expression was significantly correlated with poor patient survival. The CpG islands were hypomethylated in the promoter region of TTYH3 in HCC tissues. In conclusion, we identified TTYH3 regulates tumor development and progression via MK5/GSK3-β/β-catenin signaling in HCC and promotes itself expression in a positive feedback loop.     

Dasatinib ameliorates thioacetamide-induced liver fibrosis: modulation of miR-378 and miR-17 and their linked Wnt/β-catenin and TGF-β/smads pathways

Hepatic stellate cells activation (HSCs) plays a crucial role in the pathogenesis of liver fibrosis. Specific microRNAs have been suggested to affect the activation of HSCs via various signalling pathways including TGF-β/smads and Wnt/β-catenin pathways. Dasatinib is a multitarget inhibitor of many tyrosine kinases has recently studied for its anti-fibrotic effects in a variety of fibrous diseases. This study investigated the role of modulation of miRNA-378 and miRNA-17 in the pathogenesis of liver fibrosis through altering Wnt/β-catenin and TGF-β/smads pathways and evaluated the beneficial effect of the tyrosine kinase inhibitor, dasatinib, in thioacetamide-induced liver fibrosis model in mice. Treatment with dasatinib down-regulated miRNA-17 expression, leading to the restoration of WiF-1 and smad-7 which cause the inhibition of both Wnt/β-catenin and TGF-β/smads signalling. In addition, it upregulated miRNA-378 leading to the decrease of Wnt-10 which contributes to the suppression of activated HSCs.