Elevated expression of circular RNA circ_0008450 predicts dismal prognosis in hepatocellular carcinoma and regulates cell proliferation, apoptosis, and invasion via sponging miR‐548p

Abstract Background Circular RNA (circRNA) is emerging as an important player in human diseases, especially cancer. In our previous study, we identified a series of deregulated circRNAs in hepatocellular carcinoma (HCC) by performing circRNA microarray expression profile. Here, we aimed to explore the role of circ-LRIG3 (hsa_circ_0027345) in HCC. Methods qRT-PCR and western blot were used to asses gene and protein expression, respectively. CCK-8, EdU and Transwell assays were used to detect cell proliferation, migration and invasion. GSEA software was applied to analyze the pathway related to circ-LRIG3. Co-IP, RIP and ChIP assays were used to identify the positive feedback axis of circ-LRIG3/EZH2/STAT3. Animal study was carried to test the role of circ-LRIG3 in vivo. Results Circ-LRIG3 was notably upregulated in HCC and promoted HCC cell proliferation, migration, invasion and reduced apoptosis. Circ-LRIG3 formed a ternary complex with EZH2 and STAT3, facilitating EZH2-induced STAT3 methylation and subsequent phosphorylation, resulting in the activation of STAT3 signaling. In turn, activated STAT3 could directly bind to circ-LRIG3 promoter to increase circ-LRIG3 transcription activity, thus forming a positive feedback loop. The animal models showed that exogenous expression of circ-LRIG3 enhanced tumorigenicity and metastasis in vivo, whereas these effects were blocked after treatment with C188–9, a specific STAT3 small-molecule inhibitor. Clinically, high circ-LRIG3 was closely linked with aggressive clinicopathological features and was identified as an independent risk prognostic factor of overall survival. Importantly, plasma circ-LRIG3 was found to be a highly sensitive and specific non-invasive diagnostic indicator for HCC. Conclusions Our study reveals the carcinogenic role of circ-LRIG3 in HCC, which may provide a new therapeutic target for HCC patients.

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Circular RNA circRHOBTB3 is downregulated in hepatocellular carcinoma and suppresses cell proliferation by inhibiting miR-18a maturation

Infectious Agents and Cancer ◽

10.1186/s13027-021-00384-1 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Gang Hu ◽

Shusen Zhai ◽

Sheng Yu ◽

Zhen Huang ◽

Ran Gao

Keyword(s):

Hepatocellular Carcinoma ◽

Cell Proliferation ◽

Expression Vector ◽

Circular Rna ◽

Precursor Cell ◽

Normal Tissues ◽

Cancer Tissues ◽

Suppress Cell Proliferation ◽

Hcc Cells

Abstract Background Circular RNA circRHOBTB3 has been characterized as a tumor suppressor in gastric cancer, while its role in hepatocellular carcinoma (HCC) is unknown. This study was carried out to analyze the role of circRHOBTB3 in HCC. Methods In this study, circRHOBTB3, mature miR-18a, and miR-18a precursor in HCC and paired non-cancer tissues were detected by RT-qPCR. The role of circRHOBTB3 in the production of mature miR-18a was explored by transfecting circRHOBTB3 expression vector into HCC cells, followed by RT-qPCR to determine the expression of mature miR-18a and miR-18a precursor. The role of circRHOBTB3 and miR-18a in HCC cell proliferation was studied using CCK-8 assay. Results CircRHOBTB3 was under-expressed in HCC compared to normal tissues. In HCC cells, circRHOBTB3 overexpression decreased mature miR-18a level but not miR-18a precursor. Cell proliferation analysis showed that circRHOBTB3 overexpression decreased cell proliferation while miR-18a overexpression increased cell proliferation. Moreover, circRHOBTB3 suppressed the role of miR-18a in cell proliferation. Conclusions CircRHOBTB3 is downregulated in HCC and may suppress cell proliferation by reducing miR-18a production.

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Elevated Circular RNA PVT1 Promotes Eutopic Endometrial Cell Proliferation and Invasion of Adenomyosis via miR-145/Talin1 Axis

BioMed Research International ◽

10.1155/2021/8868700 ◽

2021 ◽

Vol 2021 ◽

pp. 1-15

Author(s):

Yi-Yi Wang ◽

Hua Duan ◽

Sha Wang ◽

Yong-Jun Quan ◽

Jun-Hua Huang ◽

...

Keyword(s):

Cell Proliferation ◽

Circular Rna ◽

Endometrial Tissue ◽

Luciferase Reporter ◽

Circular Rnas ◽

Regulatory Effect ◽

Endometrial Cell ◽

Elevated Expression ◽

Proliferation And Invasion

Several theories on the origin of adenomyosis (ADS) have been proposed, of which the most widely accepted is the fundamental pathogenic role of uterine eutopic endometrium. Emerging evidence suggests that circular RNAs participate in the multiple tumorgenesis. The vital importance of circular RNA PVT1 (circPVT1) in the pathological progress like malignancies has been well documented. Nevertheless, its underlying correlation with ADS remains elusive yet. The purpose of this study was to investigate the expression pattern, regulatory effect, and internal mechanism of circPVT1 in ADS. qRT-PCR was performed to detect the relative mRNA expression of circPVT1, miR-145, and Talin1 in ADS endometrial tissue and cells. The protein level of Talin1 was measured by Western blot and immunochemistry. Immunofluorescence was used to identify the primary endometrial epithelial and stromal cells. circPVT1 knockdown in vitro was achieved by transfecting with specific lentivirus vector CCK-8, and colony formation assays were utilized to assess cell proliferation; meanwhile, the transwell assay was employed for evaluating cell invasion ability. By conducting bioinformatics, dual-luciferase reporter assay, or RNA immunoprecipitation (RIP) experiment, the interaction between miR-145 and circPVT1 or Talin1 was verified. Rescue experiments further determined the regulatory effect of circPVT1/miR-145/Talin1 axis. We found both circPVT1 and Talin1 were markedly upregulated in ADS endometrial tissue and cells, whereas miR-145 was decreased. Elevated expression of circPVT1 was closely related to the severity of dysmenorrhea, menorrhagia, and uterine enlargement of patients with ADS. Knockdown of circPVT1 inhibited adenomyotic epithelial and stromal cell proliferation and invasion. Further mechanistic experiments revealed that circPVT1 negatively regulated miR-145 through serving as a molecular sponge. And the facilitating effect of circPVT1 was partially reversed by miR-145. Talin1 was demonstrated to be a down target of miR-145 and indirectly affected by circPVT1. Our findings unveiled that enhanced circPVT1 may be involved in the pathogenesis of ADS via stimulating endometrial cell proliferation and invasion. The establishment of circPVT1/miR-145/Talin1 pathway might present a novel therapeutic insight for ADS.

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A novel circular RNA circ-LRIG3 facilitates the malignant progression of hepatocellular carcinoma by modulating the EZH2/STAT3 signaling

10.21203/rs.3.rs-71500/v2 ◽

2020 ◽

Author(s):

Suofeng Sun ◽

Jing Gao ◽

Shen Zhou ◽

Yuan Li ◽

Yu Wang ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Cell Proliferation ◽

Positive Feedback ◽

Circular Rna ◽

Migration And Invasion ◽

Stat3 Signaling ◽

Gene And Protein Expression ◽

Important Player

Abstract Background: Circular RNA (circRNA) is emerging as an important player in human diseases, especially cancer. In our previous study, we identified a series of deregulated circRNAs in hepatocellular carcinoma (HCC) by performing circRNA microarray expression profile. Here, we aimed to explore the role of circ-LRIG3 (hsa_circ_0027345) in HCC.Methods: qRT-PCR and western blot were used to asses gene and protein expression, respectively. CCK-8, EdU and Transwell assays were used to detect cell proliferation, migration and invasion. GSEA software was applied to analyze the pathway related to circ-LRIG3. Co-IP, RIP and ChIP assays were used to identify the positive feedback axis of circ-LRIG3/EZH2/STAT3. Animal study was carried to test the role of circ-LRIG3 in vivo.Results: Circ-LRIG3 was notably upregulated in HCC and promoted HCC cell proliferation, migration, invasion and reduced apoptosis. Circ-LRIG3 formed a ternary complex with EZH2 and STAT3, facilitating EZH2-induced STAT3 methylation and subsequent phosphorylation, resulting in the activation of STAT3 signaling. In turn, activated STAT3 could directly bind to circ-LRIG3 promoter to increase circ-LRIG3 transcription activity, thus forming a positive feedback loop. The animal models showed that exogenous expression of circ-LRIG3 enhanced tumorigenicity and metastasis in vivo, whereas these effects were blocked after treatment with C188-9, a specific STAT3 small-molecule inhibitor. Clinically, high circ-LRIG3 was closely linked with aggressive clinicopathological features and was identified as an independent risk prognostic factor of overall survival. Importantly, plasma circ-LRIG3 was found to be a highly sensitive and specific non-invasive diagnostic indicator for HCC.Conclusions: Our study reveals the carcinogenic role of circ-LRIG3 in HCC, which may provide a new therapeutic target for HCC patients.

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