The Combination of circEPSTI1 and MIF Offers Diagnostic Value for Endometrial Cancer

Background

Circular RNAs (circRNAs) exhibit unique patterns of expression and high levels of stability in patient plasma samples such that they represent ideal non-invasive biomarkers that can be leveraged to detect a wide array of diseases including endometrial cancer (EC). This study was designed to identify circRNAs with potential diagnostic utility in serum samples from EC patients while also evaluating the utility of macrophage migration inhibitory factor (MIF) as a biomarker when screening for this form of cancer in the clinic.

Methods

Levels of circEPSTI1 and MIF were assessed in the plasma of EC patients and healthy subjects (n=186 each) through qPCR and ELISAs. The diagnostic utility of these biomarkers was assessed with receiver operating characteristic curve (ROC) analyses.

Results

Relative to healthy subjects, EC patient serum contained significantly elevated circEPSTI1 and MIF. An association was noted between circEPSTI1 expression in stages, histologic grade, and residual tumor. ROC curves confirmed that serum circEPSTI1 levels distinguished between controls and patients with EC with an Area of 0.835 and serum MIF levels distinguished between controls and patients with EC with an Area of 0.6646. When instead diagnosing patients based on the combination of MIF and circEPSTI1, the Area further rose to 0.8604.

Conclusion

Assessing the combination of circEPSTI1 and MIF may be a viable approach to reliably diagnosing EC.

circEPSTI1 promotes tumor progression and cisplatin resistance via upregulating MSH2 in cervical cancer

CircRNAs (circRNAs) are a kind of non-coding RNAs which are extensively distributed in tissues. Previous investigations reported that circRNAs harbor indispensable roles in modulating the progress of multiple cancers. Nevertheless, the function along with the molecular mechanism of most circRNAs in cervical cancer progression was still not clear. Herein, we illustrated that circEPSTI1 is a remarkably upregulated circRNA, which we validated in tissues with cervical cancer along with cell lines. The biological role of circEPSTI1 in the advancement of cervical cancer was probed via loss-of function assessments. Silencing circEPSTI1 could diminish the proliferative capacity of the cervical cancer cells to spread. In cervical cancer cells, silencing circEPSTI1 dramatically elevated drug responsivity to cisplatin. Mechanically, RNA immuno-precipitation experiments and dual luciferase enzyme reporter experiments were conducted to reveal the molecular mechanism of circEPSTI1 in cervical cancer. In conclusion, this research premise identified the biological function of circEPSTI1-miR-370-3p-MSH2 axis in cervical cancer progression. Our result is significant for slowing the progress of and overcoming drug resistance of cervical cancer.

Circular RNA circEPSTI1 accelerates cervical cancer progression via miR-375/409-3P/515-5p-SLC7A11 axis

Background: Circular RNAs (circRNAs) is one kind of non-coding RNAs (ncRNAs) and exert crucial functions in biological processes and intracellular gene expression modulation. However, the biological roles and expression status of the majority of circRNAs still remain unknown in cervical cancer.

Results: In this study, circEPSTI1 (hsa_circRNA_000479) was significantly upregulated in cervical cancer. We first discovered the impact of circRNA on cell ferroptosis in cervical cancer. Interestingly, circEPSTI1 attenuates the effect of ferritin which is mediated by SLC7A11 based on lipid peroxidation measurements and reduced glutathione and glutathione (GSH/GSSG) assay.

Conclusions: circEPSTI1-miR-375/409-3P/515-5p-SLC7A11 axis affected the proliferation of cervical cancer via the competing endogenous RNAs (ceRNA) mechanism and was relative to ferroptosis. Our findings provided experimental evidences which revealed that circEPSTI1 might act as a new and useful biomarker for monitoring and treatment target for cervical cancer.

Methods: The expression of circEPSTI1 was examined in cervical cancer cells. Then, we observed the impact of circEPSTI1 expression on the proliferation of cervical cancer by loss-of-function assays both in vivo and vitro. RIP and luciferase reporter assay revealed that circEPSTI1 sponges miR-375, miR-409-3p and miR-515-5p to upregulate SLC7A11 expression. We applied mouse xenograft experiments in mice to validate our results.

circEPSTI1 Acts as a ceRNA to Regulate the Progression of Osteosarcoma

BACKGROUND

Recent studies have reported the vital roles of circular RNAs (circRNAs) in tumor progression. However, the function and expression profile of most circRNAs in osteosarcoma remain unclear.

METHODS

We examined the expression of circEPSTI1, a circRNA, in 50 paired adjacent normal tissues and osteosarcoma tissues by qRT-PCR. Then, we further explored the function of circEPSTI1 in osteosarcoma progression in vitro and in vivo. For example, cell proliferation and migration were examined. Some experiments were performed to explore the regulatory function of circEPSTI1 in miRNA and to investigate the potential role of circEPSTI1 in osteosarcoma.

RESULTS

We found that circEPSTI1 was significantly upregulated in osteosarcoma. Inhibition of circEPSTI1 suppressed the osteosarcoma cancer cell proliferation and migration in vitro. Dual luciferase reporter assay showed that circEPSTI1 and MCL1 (myeloid cell leukaemia 1) could bind to miR-892b and that MCL1 and circEPSTI1 were targets of miR-892b.

CONCLUSION

Thus, the circEPSTI1-miR-892b-MCL1 axis affected osteosarcoma progression through the miRNA sponging mechanism. circEPSTI1 may serve as a target and biomarker for osteosarcoma treatment.

Downregulation of circEPSTI1 represses the proliferation and invasion of non-small cell lung cancer by inhibiting TRIM24 via miR-1248 upregulation

The circular RNA (circRNA) circEPSTI1 has been recently identified as a new cancer-associated circRNA in multiple types of cancer. However, the involvement of circEPSTI1 in non-small cell lung cancer (NSCLC) remains unexplored. The purpose of this study was to explore the expression pattern and function of circEPSTI1 in NSCLC. We found that circEPSTI1 expression was significantly elevated in NSCLC. In vitro experiments elucidated that knockdown of circEPSTI1 caused a significant reduction in NSCLC cell proliferation and invasion. Moreover, circEPSTI1 was identified as an miRNA sponge of miRNA-1248. Knockdown of circEPSTI1 markedly increased the expression of miR-1248 in NSCLC cells. Upregulation of miR-1248 significantly restricted the proliferation and invasion of NSCLC cells. Inhibition of miR-1248 promoted the proliferation and invasion of NSCLC cells and blocked the circEPSTI1 knockdown-mediated inhibitory effect on NSCLC cell proliferation and invasion. Subsequent data revealed that the tumor-promoting gene tripartite motif-containing protein 24 (TRIM24) is a target gene of miR-1248. The upregulation of TRIM24 partially reversed circEPSTI1 knockdown- or miR-1248 overexpression-induced tumor suppressive effect in NSCLC cells. In summary, our data demonstrate that downregulation of circEPSTI1 represses the proliferation and invasion of NSCLC by inhibiting TRIM24 via miR-1248 upregulation.

CircEPSTI1 Promotes the Progression of Non-Small Cell Lung Cancer Through miR-145/HMGB3 Axis

Background

The high expression of circular RNA circEPSTI1 (hsa_circRNA_000479) has been reported to be associated with the malignant potential of ovarian cancer cells and triple-negative breast cancer cells. However, the expression profile and function of circEPSTI1 in non-small cell lung cancer (NSCLC) are not fully addressed.

Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to measure the RNA expression of circEPSTI1, relevant microRNAs (miRNAs) and high mobility group box 3 (HMGB3) in NSCLC tissues and cells. Cell counting kit 8 (CCK8) assay, colony formation and transwell assays were conducted to detect the capacities of proliferation, colony formation and metastasis in NSCLC cells. Western blot assay was performed to detect the expression of metastasis-associated proteins and HMGB3. Animal experiment was carried out to confirm the function of circEPSTI1 in vivo. The combination between miR-145 and circEPSTI1 or HMGB3 was verified by dual-luciferase reporter assay, RNA pull-down and RIP assays.

Results

CircEPSTI1 was abnormally up-regulated in NSCLC tissues and cells in comparison with that in normal tissues and cells. The high expression of circEPSTI1 was associated with the low survival rate of NSCLC patients. CircEPSTI1 accelerated the proliferation, colony formation and motility of NSCLC cells in vitro. CircEPSTI1 silencing restrained the NSCLC tumor growth in vivo. miR-145 was validated as a target of circEPSTI1 in NSCLC cells. HMGB3 was a direct downstream target of miR-145 in NSCLC cells. The decreased abilities of proliferation, colony formation and metastasis caused by the silencing of circEPSTI1 were reversed by the depletion of miR-145 or the accumulation of HMGB3 in NSCLC cells.

Conclusion

CircEPSTI1 aggravated the progression of NSCLC through elevating the expression of HMGB3 via sponging miR-145.

circEPSTI1 regulates ovarian cancer progression via decoying miR-942

Increasing studies show that circular RNAs (circRNAs) play vital roles in tumour progression. But, how circRNAs function in ovarian cancer is mostly unclear. Here, we detected the expression of circEPSTI1 in ovarian cancer and explored the function of circEPSTI1 in ovarian cancer via a series of experiments. Then, we performed luciferase assay and RNA immunoprecipitation (RIP) assay to explore the competing endogenous RNA (ceRNA) function of circEPSTI1 in ovarian cancer. qRT-PCR verified that circEPSTI1 was overexpressed in ovarian cancer. Inhibition of circEPSTI1 suppressed ovarian cancer cell proliferation, invasion but promoted cell apoptosis. Luciferase assays and RIP assay showed that circEPSTI1 and EPSTI1 (epithelial stromal interaction 1) could directly bind to miR-942. And circEPSTI1 could regulate EPSTI1 expression via sponging miR-942. In summary, circEPSTI1 regulated EPSTI1 expression and ovarian cancer progression by sponging miR-942. circEPSTI1 could be used as a biomarker and therapeutic target in ovarian cancer.

circEPSTI1 as a Prognostic Marker and Mediator of Triple-Negative Breast Cancer Progression

Circular RNAs (circRNAs) represent a class of non-coding RNAs that play a vital role in modulating gene expression and several pathological responses. However, the expression profile and function of circRNAs in triple-negative breast cancer (TNBC) remain unknown. In the current study, we investigated the expression profile of human circRNAs in TNBC tissues and identified circEPSTI1 (hsa_ circRNA_000479) as a significantly upregulated circRNA.

Methods: We performed circular RNA microarray assays to screen circular RNA expression profiles of TNBC and further investigated circEPSTI1. We observed the effect of circEPSTI1 on proliferation, clonal formation and apoptosis in TNBC by knocking downcircEPSTI1 in three TNBC cell lines. Based on the MRE analysis and luciferase reporter assay, we found that circEPSTI1 binds to miRNAs as a miRNA sponge and the co-target genes of miRNAs. We performed xenograft experiments in mice to confirm our findings. We evaluated circEPSTI1 levels in 240 TNBC patients by ISH.

Results: Knockdown of circEPSTI1 inhibits TNBC cell proliferation and induces apoptosis. In vitro and in vivo experiments indicated that circEPSTI1 binds to miR-4753 and miR-6809 as a miRNA sponge to regulate BCL11A expression and affect TNBC proliferation and apoptosis. High levels of circEPSTI1 correlate with reduced survival in TNBC patients.

Conclusions: The circEPSTI1-miR-4753/6809-BCL11A axis affect the proliferation and apoptosis of triple-negative breast cancer through the mechanism of competing endogenous RNAs (ceRNA). In addition, our results identify circEPSTI1 as an independent prognostic marker for survival in patients with TNBC.