CircASPH promotes KGN cells proliferation through miR-375/MAP2K6 axis in Polycystic Ovary Syndrome.

Polycystic Ovary Syndrome (PCOS) is a kind of endocrine disorder which is prevalent in adult women, so exploring more biomarkers for PCOS is imperative. Recently, circular RNA and microRNA are confirmed to be related with PCOS development. Whether circular RNA ASPH (circASPH) is involved in PCOS need to be studied further. We utilized RT-qPCR to measure the expression levels of circASPH, miR-375 and MAP2K6 in PCOS patients and normal group. The effects of circASPH and miR-375 on KGN cells proliferation and apoptosis were observed by CCK-8 assay, EdU incorporation assay and apoptosis assay, separately. Then Dual-luciferase reporter assay was carried out to verify the circASPH/miR375 axis and miR375/MAP2K6 axis. The interaction between circASPH and MAP2K6 were detected with the support of RT-qPCR and Western blot. We found circASPH and MAP2K6 were both over-expressed in PCOS patients, while miR-375 was in the opposite direction. Moreover, miR-375 was negatively regulated by circASPH, while MAP2K6 was positively regulated by circASPH. In addition, circASPH directly targeted miR-375, which targeted MAP2K6. More than that, the knockdown of circASPH repressed KGN cells proliferation and enhanced apoptosis, while the silence of miR-375 reversed the above effects. In conclusion, circASPH promotes KGN cells proliferation through miR-375/MAP2K6 axis in PCOS, and they are thought-provoking biomarkers for PCOS diagnosis and therapy.

CircASPH Enhances Exosomal STING to Facilitate M2 Macrophage Polarization in Colorectal Cancer.

Exosomes are considered a mediator of communication within the tumor microenvironment (TME), which modulates cancer progression through transmitting cargos between cancer cells and other cancer-related cells in TME. Circular RNAs (circRNAs) have emerged to be regulators in colorectal cancer (CRC) progression, but most of them have not been discussed in CRC. This study aims to investigate the role of circRNA aspartate beta-hydroxylase (circASPH) in CRC progression and its correlation with exosome-mediated TME. At first, we determined that circASPH was upregulated in CRC samples and cell lines. Functionally, the circASPH deficiency suppressed the malignant processes of CRC cells and also inhibited in vivo tumor growth via enhancing antitumor immunity. Mechanically, circASPH facilitated macrophage M2 polarization by upregulating exosomal stimulator of interferon genes (STING). CircASPH interacted with insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) to stabilize IGF2BP2 protein, therefore enhancing the stability of m6A-modified STING mRNA. In turn, coculture of STING-overexpressed macrophages recovered the suppression of silenced circASPH on the malignancy of CRC cells both in vitro and in vivo. Our study demonstrated that circASPH enhances exosomal STING to facilitate M2 macrophage polarization, which further accelerates CRC progression. The findings support circASPH as a promising therapeutic target for CRC treatment.

CircASPH is markedly overexpressed in CRC cell lines and promotes CRC progression. CircASPH deficiency inhibits in vivo tumor growth via enhancing antitumor immunity. CircASPH upregulates STING to enhance M2 macrophage polarization.

CircASPH Promotes Hepatocellular Carcinoma Progression Through Methylation and Expression of HAO2.

CircRNAs have been reported to be related to hepatocellular carcinoma (HCC) development. Limited studies have revealed the expression profile of circRNAs in tumor and para-tumor normal samples in HCC patients. We found that circASPH was significantly increased in HCC tumor samples and that the level of circASPH was closely related to the overall survival of HCC patients. Mechanistically, circASPH could regulate the methylation of the promoter and expression of hydrocyanic oxidase 2 (HAO2) to promote HCC progression by acting as a sponge for miR-370-3p, and miR-370-3p could target DNMT3b and increase the 5mC level. In summary, our study determined that circASPH could regulate the methylation and expression of HAO2 and it could be considered an important epigenetic regulator in HCC progression.

Upregulation of circ-ASPH contributes to glioma cell proliferation and aggressiveness by targeting the miR-599/AR/SOCS2-AS1 signaling pathway.

Glioma (GM) is the most common type of malignant brain tumor with a high recurrence rate. Circular RNAs (circRNAs) play a key role in mediating tumorigenesis. However, the functions and mechanisms of circRNAs in GM are still not fully understood. A circRNA microarray was performed to identify differentially expressed circRNAs in GM and non-cancerous specimens. Reverse transcription-quantitative PCR was used to detect circ-aspartyl/asparaginyl ß-hydroxylase (ASPH) expression in GM tissues and cells. The clinical importance of circ-ASPH was investigated using Kaplan-Meier analysis. The functions of circ-ASPH were investigated in LN229 and U87MG cells. Bioinformatics, RNA immunoprecipitation, RNA pull-down and luciferase reporter assays were used to explore the mechanisms of circ-ASPH in GM. circ-ASPH levels were upregulated in GM specimens and cells. The prognostic role of circ-ASPH was identified in patients with GM. Loss/gain of function assays demonstrated that circ-ASPH increased cell proliferation, migration and invasion in GM cells. Mechanistically, circ-ASPH counteracted microRNA (miR)-599-mediated androgen receptor (AR) suppression by acting as a sponge for miR-599. Rescue assays indicated that circ-ASPH facilitated cell progression by regulating AR expression. Moreover, AR activated long non-coding RNA suppressor of cytokine signaling 2-antisense RNA 1 (SOCS2-AS1) expression in GM cells. Taken together, circ-ASPH/miR-599/AR/SOCS2-AS1 signaling may be a promising biomarker/therapeutic target for GM.